Scielo RSS <![CDATA[Revista Brasileira de Zootecnia]]> vol. 47 num. lang. en <![CDATA[SciELO Logo]]> <![CDATA[Metabolic and histologic responses of pacu (<em>Piaractus mesopotamicus</em>) fed diets supplemented with increasing concentrations of ractopamine]]> ABSTRACT An experiment was conducted during 60 days with forty pacu males fed diets supplemented with increasing concentrations of ractopamine (0.00, 11.25, 22.50, 33.75, and 45.00 mg kg−1). Eight fish were evaluated for each experimental diet. Performance and survival rate of the fish were measured. At the end of the experiment, blood was collected to determine the levels of cortisol, triacylglycerol, and protein. Moreover, the liver was collected to determine the activities of glucose-6-phosphate dehydrogenase and malic enzymes. The fillets were collected to determine chemical composition, and histologic cuts were analyzed to verify muscle growth and deposition of adipose tissue between muscle fibers. Increasing concentrations of dietary ractopamine did not change feed intake, fillet yield, fillet content of protein and ash, and frequency of relative distribution of muscle fibers. By increasing the dietary ractopamine concentration, the serum cortisol level was elevated. Ractopamine supplementation (45.00 mg kg−1) increased serum levels of triacylglycerol and protein and reduced the activity of hepatic lipogenic enzymes and the survival rate of the fish, probably in response to the high concentration of circulating cortisol. In addition, the higher level of ractopamine supplementation evaluated in this research impaired the weight gain and feed conversion. However, 11.25 mg kg−1 ractopamine reduced the ether extract level determined in the fillet and the fat deposition between muscle fibers, improving the nutritional quality of meat. <![CDATA[Maintenance of <em>Octopus vulgaris</em> Type II paralarvae in an estuarine area]]> ABSTRACT We assessed the survival of paralarvae kept in a floating wooden box attached to an oyster extensive cultivation system with no extra food supply. A total of 7700 newly hatched paralarvae were maintained in a 10.5-L floating box (7 cm height × 30 cm width × 50 cm length) covered with a 180-μm mesh net for 14 days with no extra food supply. Skin damages and tentacle deformities were observed in 43% of the paralarvae at 14 days after hatching (DAH). The survival rate was 64.7% at 7 DAH and 42.8% at 14 DAH. The floating box is a promising structure for culturing O. vulgaris paralarvae in an extensive system. <![CDATA[Evaluation of some oxidative-stress and antioxidant markers in goats during estrous cycle under Egyptian environmental conditions]]> ABSTRACT The objective of this study was to explore the impact of thermal stress on hormonal level and antioxidant activity in goats during various phases of the estrous cycle in the Egyptian summer. Forty cycling does were allocated to two groups (20 animals each) divided by season (mild/hot). Daily meteorological, rectal temperature, and respiratory rate data were recorded in the two seasons. The estrous cycle of the goats was synchronized by two intramuscular injections of 5 mg of prostaglandin F2α (PGF2α) at 11-day intervals. Blood samples were collected every two days and the levels of total antioxidant, malondialdehyde, and β-carotene were estimated. Total protein, albumin, cholesterol, triglycerides, progesterone, and thyroxine (T4) hormones were additionally measured in the serum of the collected samples. Under hot circumstances, both rectal temperature and respiratory rate increased considerably, with significant variation during the different stages of the estrous cycle. On the other hand, serum level of total protein, albumin, cholesterol, and triglycerides reduced significantly in animals in the hot environment, particularly during the luteal period of the estrous cycle (IV). During the Egyptian hot summer, the serum level of progesterone and T4 hormones declined in phases II and IV of the estrous cycle for progesterone and T4, respectively. Moreover, the serum content of all oxidative stress markers tested (total antioxidant, β-carotene, and malondialdehyde) decreased considerably, especially in estrous cycle phase II in the hot environment. The Egyptian environmental conditions have detrimental effects on some antioxidant agents and some biochemical parameters throughout the estrous cycle of goats. <![CDATA[Effects of dietary grape seed on performance and some metabolic assessments in Japanese quail with different plumage colors exposed to heat stress]]> ABSTRACT The objective of this study was to determine the effects of grape seed (GS) supplementation to basal diet on performance, carcass characteristics, some biochemical parameters, and antioxidant status of tissues of Japanese quail in growth phase with different plumage colors exposed to heat stress (HS). A total of 144 eight-day-old Japanese quail including 72 (36 females, 36 males) grey and 72 (36 females, 36 males) golden were used in this study. The quail were kept under HS (16 h at 34 °C, 8h at 22 °C) and thermo-neutral (24 h at 22°C) conditions between 15 and 43 days of age. All quail were fed a basal diet (control) and basal diet supplemented with GS at both 10 g/kg and 20 g/kg ratios. Each feeding treatment was repeated three times including four quail (two females and two males) per replicate. Heat stress considerably decreased the live weight gain on days 29-36, 36-43, and 15-43. Golden quail had higher live weight from the beginning of the trial. The increase of live weight on days 15-43 was higher in the golden group than in the grey group. Malondialdehyde (MDA) levels of liver and kidney tissues increased in heat-stress group compared with thermo-neutral group (P&lt;0.001). In HS, significant increases were determined only in catalase (CAT) in the liver and in glutathione peroxidase (GSH-Px), CAT, and glutathione (GSH) in the kidney (P&lt;0.05). Addition of dietary GS decreased MDA and antioxidant levels, which increased in liver and kidney of quail during HS. Plasma total cholesterol, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels were higher in quail under HS. Plasma total cholesterol, glucose, triglyceride, AST, and ALT levels of quail under HS decreased due to addition of 10 g/kg GS. <![CDATA[Integrating the pastoral component in agricultural systems]]> ABSTRACT This paper aims to discuss the impact of the introduction of pastures and grazing animals in agricultural systems. For the purposes of this manuscript, we focus on within-farm integrated crop-livestock systems (ICLS), typical of Southern Brazil. These ICLS are designed to create and enhance the synergisms and emergent properties have arisen from agricultural areas where livestock activities are integrated with crops. We show that the introduction of the crop component will affect less the preceding condition than the introduction of the livestock component. While the introduction of crops in pastoral systems represents increasing diversity of the plant component, the introduction of animals would represent the entry of new flows and interactions within the system. Thus, given the new complexity levels achieved from the introduction of grazing, the probability of arising emergent properties is theoretically much higher. However, grazing management is vital in determining the success or failure of such initiative. The grazing intensity practiced during the pasture phase would affect the canopy structure and the forage availability to animals. In adequate and moderate grazing intensities, it is possible to affirm that livestock combined with crops (ICLS) has a potential positive impact. As important as the improvements that grazing animals can generate to the soil-plant components, the economic resilience remarkably increases when pasture rotations are introduced compared with purely agriculture systems, particularly in climate-risk situations. Thus, the integration of the pastoral component can enhance the sustainable intensification of food production, but it modifies simple, pure agricultural systems into more complex and knowledge-demanding production systems. <![CDATA[Accumulation and export of nutrients in cactus pear cladodes (<em>Opuntia ficus-indica</em>) under different managements in the Brazilian Semiarid]]> ABSTRACT The present study evaluated the accumulation and export of nutrients in cactus pear (Opuntia ficus-indica) cv. Gigante, fertilized with combinations of nitrogen (10, 70, 100, 130, and 190 kg ha−1 year−1 N) and phosphorus (10, 70, 100, 130, and 190 kg ha−1 year−1 P2O5) under annual and biennial harvests, in Quixadá and Tejuçuoca, using a split-plot randomized block design with four replications. In Quixadá, under annual and biennial harvests, the following orders of accumulation of macronutrients (in kg ha−1 year−1) were found, respectively: K (98.8) &gt; Ca (87.2) &gt; N (46.7) &gt; Mg (26.8) &gt; S (18.4) &gt; P (2.04) and Ca (33.5) &gt; K (31.1) &gt; S (18.6) &gt; N (12.9) &gt; Mg (10.5) &gt; P (0.81). In Tejuçuoca, under annual and biennial harvests, the orders of accumulation of macronutrients were, respectively: K (146.5) &gt; Ca (204.6) &gt; N (128.1) &gt; Mg (75.8) &gt; S (50.3) &gt; P (3.7) and K (397.2) &gt; N (191.3) &gt; S (241.2) &gt; Ca (167.8) &gt; Mg (131.0) &gt; P (14.1). The maintenance/production fertilization in cactus pear should be planned according to productive potential, fertilization and harvest managements, and cultivation region, based on nutritional requirement and considering the nutrient recovery efficiency. <![CDATA[Development and reproductive performance of Hereford heifers of different frame sizes up to mating at 14-15 months of age]]> ABSTRACT Body development and reproductive performance of a hundred forty-two 14 to 15-month-old heifers, classified at weaning according to frame size as small, medium, and large, were evaluated. The parameters evaluated were: body weight, hip height, body condition score, weight gain, ovarian activity, and pregnancy rate. At weaning, body weight and hip height were significantly different among frame scores, (small – 133.0 kg, 92.2 cm; medium – 158.5 kg, 96.6 cm; and large – 185.2 kg; 100.2 cm). After weaning, heifers grazed together on natural pastures during the autumn and on ryegrass (Lolium multiflorum La.) during the winter and spring. Frame score differences remained until the beginning of the breeding season (BS), starting on average at 14 months of age. Weight gain between weaning and the beginning of BS was not different among frame scores (0.740 kg/day, on average). Body weights at the beginning of the BS were significantly different, of 255.7 kg (53.3% of the mature weight) for small heifers, 285.0 kg (59.4%) for medium heifers, and 307.6 kg (64.1%) for large heifers. Ovarian activity at the beginning of the BS was not different among the three groups. The average weight gain values during the BS of 0.492, 0.472, and 0.421 kg/day for small, medium, and large heifers, respectively, were significantly different. Pregnancy rates were not different among groups (small, 71.4%; medium, 76.4%; and large, 76.5%). Frame score did not influence the reproductive performance of heifers, but the small and medium heifers conceived 29 and 20 days earlier, respectively, than the large heifers. <![CDATA[Protein and mRNA expression of gonadotropin-releasing hormone receptor in yaks during estrus]]> ABSTRACT To demonstrate the role of gonadotropin-releasing hormone (GnRH) in yaks (Bos grunniens), we characterized the expression of gonadotropin-releasing hormone receptor (GnRHR) mRNA and protein. The level of GnRHR mRNA in the hypothalamus was higher than that in the pineal gland, pituitary gland, and ovary during estrus. Immunofluorescence analysis showed that GnRHR was expressed in the pinealocyte, synaptic ribbon, and synaptic spherules of the pineal gland and that melatonin interacts with GnRHR via nerve fibers. In the hypothalamus, GnRHR was expressed in the magnocellular neurons and parvocellular neurons. In the pituitary gland, GnRHR was expressed in acidophilic cells and basophilic cells. In the ovary, GnRHR was present in the ovarian follicle and Leydig cells. Gonadotropin-releasing hormone receptor is located in the pineal gland, hypothalamus, pituitary, and gonad during estrus of yaks and is mainly expressed in the hypothalamus and ovaries during the estrus period. <![CDATA[HSF1 and HSPA6 as functional candidate genes associated with heat tolerance in Angus cattle]]> ABSTRACT The purpose of this study was to access and characterize single nucleotide polymorphisms (SNP) located within the HSF1 and HSPA6 candidate genes for adaptability in Angus breed raised in subtropical climate. Samples of DNA from 20 animals representing extreme phenotypes for adaptability traits were obtained. Sequence variations in the candidate genes were described by sequencing target regions. We identified 12 SNP located in the HSF1 gene. Moreover, four of the six SNP found in the HSPA6 gene cause amino acid substitutions in protein-coding regions. We also identified a representative SNP (called tag SNP) in a region of the HSF1 gene with high linkage disequilibrium (r2 = 0.87) that may represent 11 SNP located in this gene. Minor allele frequency observed for the SNP ranged from 0.10 to 0.50 and 0.02 to 0.21 for the HSF1 and the HSPA6 genes, respectively. Overall, almost all SNP analyzed showed significant deviation from the Hardy-Weinberg Equilibrium and half of the loci had heterozygosity greater than 0.50. The data suggest that there is sequence variability in these genes that could be exploited by breeding programs. There is genetic variation in HSF1 and HSPA6 genes in this populations of Angus breed, which is fundamental to obtain response to selection. <![CDATA[Investigation of PRL-RsaI and HaeIII gene polymorphisms in Anatolian water buffaloes bred by using PCR-RFLP method]]> ABSTRACT The objective of this study was to investigate polymorphisms both in exons 1 and 3 of prolactin (PRL) gene for milk productivity of Anatolian water buffalo breed in Sivas province in Turkey. Blood samples were collected from 129 male and female water buffaloes and DNA was isolated by using phenol/chloroform method. Samples of DNA were amplified and resulting PCR products were digested with RsaI (for exons 1 and 3) and HaeIII (for exon 1). Allelic polymorphisms were determined by separation of fragments obtained from digested PCR products in 3% agarose gel electrophoresis. AA genotype (HaeIII) and BB genotype (RsaI) of exon 1 and only AA genotype (RsaI) of exon 3 were obtained. No polymorphisms were determined in Anatolian water buffalo breed and all loci were found as monomorphic. It can be stated that Anatolian water buffalo has a higher milk and milk fat yields since BB genotype was obtained. <![CDATA[Genetic diversity assessment of the Mexican Simmental population through pedigree analysis]]> ABSTRACT The purpose of this study was to examine the genetic variability of the Mexican Simmental. Inbreeding was calculated by year for animals born from 1985 to 2014. Proportion of ancestors known, average equivalent complete generations, generation interval, and effective size, as well as the effective numbers of founders, ancestors, and founder genomes were calculated for animals born in six periods (1985-1989, 1990-1994, 1995-1999, 2000-2004, 2005-2009, and 2010-2014). The year 1985 was selected as the initial year to form the subpopulations since the registration of the first Simmental cattle born in Mexico began in this year. Gene contributions of ancestors with the highest genetic influence were also calculated, using data of animals born in the latter period. Coefficients of inbreeding were low, ranging from 0.0068 to 0.0165. The average number of equivalent complete generations increased from 3.71, for the 1985-1989 subpopulation, to 5.83, for the 2010-2014 subpopulation. The population showed an effective population size of 186.6 animals in the last period. The numbers of founders, ancestors, and founder genomes increased from 1985 to 2004, but decreased from 2005 to 2014. The ratio of effective number of ancestors to effective number of founders and the ratio of effective number of founder genomes to effective number of ancestors were 0.31 and 0.66 and 0.27 and 0.63 for animals born in the 2005-2009 and 2010-2014 periods, respectively, revealing loss of diversity due to bottlenecks and genetic drift in the last decade. One ancestor explained 3.4% of the total genetic variability of the progeny born from 2010 to 2014, whereas the first fifteen ancestors explained 20% of such variability. The pedigree analysis showed Mexican Simmental cattle are not currently endangered. <![CDATA[Impact of embryo transfer phenotypic records on large-scale beef cattle genetic evaluations]]> ABSTRACT We aimed to evaluate the impact of using embryo transfer (ET) information on weaning weight estimated breeding values (EBV) and its accuracy. Data from Hereford and Braford cattle, raised under extensive conditions in Southern Brazil, were used. A model that included ET information in addition to maternal (genetic and permanent environmental) effects as a function of foster dams was compared to a model without ET information. Accuracy of both bulls and calves increased due to inclusion of ET records in 0.04 and 0.12 points, respectively. In general, the inclusion of ET records provided a greater amount of phenotypic variance and most accurate EBV for sires and progeny. The results obtained in this study encourage the use of ET phenotypic records in large-scale genetic evaluation programs, especially for bulls that have most of their progeny coming from ET. Most of the Brazilian genetic evaluation programs do not use phenotypic records of ET animals. Therefore, breeding values are predicted based only on parentage average, which implies in underestimated accuracies. Considering that ET has been widely used in Brazil and that such information improves genetic predictions, we suggest modifying the traditional adopted models by considering ET information in the Brazilian genetic evaluations. <![CDATA[Association of <em>BoLA-DRB3</em> genotype with somatic cell count in milk of Polish Holstein cattle]]> ABSTRACT The objective of this study was to evaluate the suitability of the BoLA-DRB3 gene polymorphism to define the phenotypic value of somatic cell count of 808 Polish Holstein cows. The cows were fathered by 190 sires. The PCR-RFLP alleles were identified with the BstYI, HaeIII, and RsaI restriction enzymes. For statistical analysis, 17 alleles whose frequencies in the herds were equal to or higher than 2% were selected. Somatic cell count was analyzed based either on the lactation averages or on test-day yields. Significant relationship between the occurrence of the BoLA-DRB3 gene alleles and somatic cell count were stated. In case of estimating the effects for all lactations together, the effect of substitution was observed for 11 alleles. The overall effects of four alleles (*12, *23, *24, and *ndb) were statistically significant and their effects were repeated in at least two lactations in the analysis of each lactation separately. The most numerous relationships were found for allele *24, which influences were statistically significant in lactations I to III in the analysis of all lactations together. <![CDATA[Individual responses of growing pigs to threonine intake]]> ABSTRACT A nitrogen balance test was performed to evaluate the individual responses of growing pigs to threonine intake. Eight commercial barrows were used (body weight ranging from 15 to 20 kg). A dose-response study was performed, in which the threonine supply increased in seven equidistant steps (the seven dietary threonine levels ranged from 50 to 120% of the requirements) every three days for each pig. The levels of all other amino acids were 20% higher than the tested amino acid. Nitrogen retention as a function of threonine intake was calculated per individual and per group (NLIN and NLMixed, respectively) using a linear plateau model. The highest break point value was 42.42 g of threonine intake (the most demanding individual), whereas the lowest value was 34.16 g (the least demanding individual), corresponding to a difference of 19%. In terms of N retention, the highest plateau value was 66.71 g and the lowest was 49.48 g, with a difference of 25%. There was no significant correlation between slope and plateau values or between slope and break point values. When using the model in which all parameters were random effects, the variations in threonine intake and nitrogen retention were 1.68±1.30 and 0.01±0.10 g, respectively, and no variance in the slope of the curve was detected. The average daily threonine intake values for the maximum response obtained in the group, as calculated by the NLIN and NLMixed procedures, were 13.96 and 14.02 g/day, respectively. The threonine intake for the maximum N retention between individuals ranged from 34.16 to 42.42 g, corresponding to a difference of 19%. The current recommended intake to optimize N retention is 14.02 g/day. The group responses obtained by the NLMixed procedures are very similar to those estimated by the NLIN procedure (all individuals). <![CDATA[Effect of linseed oil sediment in the diet of pigs on the growth performance and fatty acid profile of meat]]> ABSTRACT The objective of this investigation was to examine the influence of dietary linseed oil sediment on the growth performance and fatty acid composition in the muscle tissue of pigs. Sixty-eight crossbred Swedish Yorkshire × Norwegian Landrace pigs were allocated to two trials with two different levels of linseed oil sediment. Twenty-four pigs in Trial 1 were allotted into control 1 and experimental 1, of 12 animals each, and forty-four pigs in Trial 2 were allotted into control 2 and experimental 2, of 22 animals each. In both treatments, control and experimental groups were formed by animals analogous by origin, gender, weight, and condition score. Control pigs were fed identical diets ad libitum in both trials. The treated pigs were fed the same diet as control pigs, but vegetable oil was replaced by linseed oil sediment at a rate of 25 g kg−1 (experimental group 1) in Trial 1 and 50 g kg−1 (experimental group 2) in Trial 2. The results indicated that in both trials, vegetable oil replacement for linseed oil sediment had no significant influence on the growth rate of pigs, though a tendency was observed for a more rapid daily gain. Addition of linseed oil sediment to the diets increased the content of n-3 α-linolenic (C18:3n-3), eicosatrienoic (C20:3n-3), and eicosapentaenoic (C20:5n-3) acids and total n-3 polyunsaturated fatty acids (PUFA) and decreased the C18:2n-6/C18:3n-3 and n-6:n-3 ratios and the thrombogenic index of meat. Moreover, the addition of 50 g kg−1 linseed oil sediment resulted in higher content of docosapentaenoic (C22:5n-3) fatty acid, total PUFA, and PUFA:SFA ratio. Supplementation of pig diets with linseed oil sediment increases the content of α-linolenic, eicosatrienoic, eicosapentaenoic, and docosapentaenoic fatty acids and total content of n-3 polyunsaturated fatty acids and have a positive effect by improving the polyunsaturated fatty acids:saturated fatty acids and n-6:n-3 fatty acid ratios in meat. <![CDATA[Factors affecting the performance of Pantaneiro horses]]> ABSTRACT This study aimed to assess the physical performance of Pantaneiro horses with and without equine infectious anemia (EIA) under functional conditions of cattle management. The horses were subjected to a performance test and split into two groups according to a completely randomized design: animals were chosen from populations testing positive and negative for EIA. Performance was measured as a function of a data envelopment analysis (DEA) model considering four outputs and one unitary input. The output measures were the distance achieved in the performance test, hematocrit as a weighted average over the test duration, respiratory rate as weighted average over the test duration, and the level of lactic acid at the test termination. Weights for the hematocrit and the respiratory rate output variables were determined by means of factor analysis. The performance score was a weighted average of the output variables with the weights defined by the averages of the optimum individual multipliers in the DEA analysis. Contextual variables of interest were age, horse weight, room temperature, and corporal temperature. Only groups and room temperature were statistically significant effects, as indicated by a bootstrap analysis. The performance of group positive for EIA is significantly lower than that of the group negative for EIA and room temperature has a negative effect. <![CDATA[Organic selenium supplementation is cost-effective for increasing the number of seminal doses produced by sexually mature boars]]> ABSTRACT The present experiment was carried out to evaluate the economic viability of supplementing boar diets with organic selenium aiming to increase the number of seminal doses of sexually mature boars. Twelve boars were divided into three groups: control group received 0.3 mg kg−1 Se from sodium selenite (n = 4), inorganic group received 0.5 mg kg−1 Se from sodium selenite (n = 4), and organic group received 0.5 mg kg−1 Se from Sel-PlexTM (Alltech, Inc., n = 4). The experiment was conducted within 10 weeks and analysis was performed fortnightly. No interaction was observed between treatments and weeks for any of the variables analyzed. Boars fed diet supplemented with 0.5 mg kg−1 of organic selenium exhibited a 23% increase in the seminal doses, which resulted in a 37% reduction in the cost of diet per dose produced by boars in this group compared with boars in the inorganic group. It should be pointed out that the total revenue produced by the organic group was 26% higher than the inorganic group. The feeding of organic Se increases the number of seminal doses and reduces the average cost of the diet, demonstrating to be cost-effective. <![CDATA[Estimation of growth parameters of body weight and body nutrient deposition in males and females of meat- and laying-type quail using the Gompertz model]]> ABSTRACT The objective of this study was to estimate the growth parameters of body weight and body nutrient deposition in males and females of one meat- (Coturnix coturnix coturnix) and two laying-type quail strains (Coturnix coturnix japonica), designated either yellow or red, using the Gompertz model. A total of 1350 quail from 1 to 42 days of age were used and they were distributed in a completely randomized design, with five replications for each strain. The parameters of body weight and body composition of the quail were analyzed weekly and evaluated using the Gompertz equation; growth rates and body nutrient deposition were evaluated through derivative equations. The three strains evaluated showed differences in their potential, growth rates, and body chemical composition. The composition up to 42 days of age was not sufficient to adjust the fat deposition data using Gompertz. Due to the period evaluated, the Gompertz model allowed to verify that females have higher body growth rates when compared with males of the same strains, with accelerated growth up to 14 and 21 days of age for males and females, respectively. Regarding the laying strain, the red has greater growth, with similar potential in depositing protein and water in the carcass, but they are more precocious in the deposition of these nutrients. <![CDATA[Antioxidant effect of the guava byproduct in the diet of broilers in the starter phase]]> ABSTRACT This work aimed to investigate the antioxidant capacity of the guava agroindustrial waste as a functional additive in broiler feed to improve the performance and meat quality of boilers. The experiment was conducted in a completely randomized design, consisting of four treatments and six replicates with 12 birds. Treatments included different levels of guava byproduct in the feed: 0, 0.5, 1.0, and 1.5%. We evaluated the performance of broilers at 7 and 21 days old. At 21 days old, two birds from each experimental unit were euthanized for intestine histologic evaluation (duodenum, jejunum, and ileum) and breast and deboned thigh samples were collected for analyzes of pH, colorimetry (L*, a*, and b*), and thiobarbituric reactive substances (TBARS). The use of guava byproduct in the diet at 7 days old did not affect feed intake and feed conversion of the birds. However, the body weight and weight gain increased linearly with the inclusion of the byproduct. At 21 days old, the guava byproduct did not depress the performance of birds. There was no effect of treatments on villus height, crypt depth, and villus:crypt ratio of the duodenum and jejunum of the birds. The inclusion of guava byproduct resulted in lower crypt depth and linear increase in villus:crypt ratio of the ileum. There was no significant difference in pH and colorimetry of the breast and thigh. With increasing inclusion of byproduct, TBARS value was reduced to 0.72%, indicating greater lipid stability in thigh meat in this inclusion amount. Guava byproduct can be used as an alternative antioxidant additive in broiler feed because it does not depress the productive performance and improves thigh meat quality of boilers. <![CDATA[Effects of 1,25-dihydroxycholecalciferol and reduced vitamin D<sub>3</sub> level on broiler performance and bone quality]]> ABSTRACT This study was conducted to evaluate the effect of two levels of vitamin D3 with or without 1,25- dihydroxycholecalciferol (1,25(OH)2D3) on live performance and bone quality of broiler chickens. For that, we used a completely randomized design in a 2 × 2 factorial arrangement, with eight replicates of 30 Cobb®500 male broiler chicks each (n = 960). The two levels of vitamin D3 and the addition or not of 0.5 μg 1,25(OH)2D3/kg were considered as main factors. The vitamin D3 levels were: 2500/2000 IU/kg and 1250/1000 IU/kg for the starter (1 to 21 days) and grower (22 to 40 days) phases, respectively, with the first representing the levels used in industry (100%) and the second, a reduction in 50% of those levels. The 1,25(OH)2D3 source was Solanum glaucophyllum. On days 21 and 40, one broiler per replicate was killed and long bones were removed for analyses of mineral percentage, bone mineral density, biomechanical properties, and morphology. No significant differences were found related to vitamin D3 levels and the addition or not of 1,25(OH)2D3 for live performance, mineral percentage, strength, stiffness, and morphology. Toughness was lower when 1,25(OH)2D3 was used at 21 days, but this effect was not observed at 40 days of age. Bone mineral density was greater when 100% of vitamin D3 was used at 40 days of age. The reduction of up to 50% of vitamin D3 levels is sufficient to ensure performance and bone development of broilers at 21 and 40 days of age. The inclusion of 0.5 μg 1,25(OH)2D3/kg in addition to diets with sufficient levels of vitamin D3 shows no effect on the improvement of those parameters at the same ages. <![CDATA[Glycemic control in minks with tendency to obesity in the perinatal period with the use of HbA1C]]> ABSTRACT The objective of this study was to investigate the usefulness of HbA1C as a test in monitoring the long-term glycemic control during the perinatal period in minks with the tendency to obesity. On the scanbrown mink farm, screening research on one-year-old females showing predilections to obesity was conducted. In the first year of the experiment, 120 females were assessed using body condition score (BCS) system. The two groups that differed significantly in body weight were selected based on the BCS system and then two treatment groups of 30 females were formed: BCS II (lean) and BCS IV (thick). The groups were subjected to tests during the two years of the experiment. The biological material was urine and blood taken from vena safena five times a year. In whole blood, the level of glycosylated hemoglobin A1C was determined by ion exchange chromatography with chromatographic-spectrophotometric test (BioSystems S.A. company). Plasma glucose level was determined using Cormay reagents and BS 130 apparatus. The level of glucose in urine was also determined using diagnostic Medi-Test Combi 10 VET strips. The results were statistically analyzed using the SAS Enterprise Guide 5.1. The descriptive statistics and the analysis of one-way variance (ANOVA) were used. Statistically significant differences were analyzed by Tukey test at the significance level α = 0.05. Glycosuria was found in females in all studied stages of the production cycle. In both BCS II and BCS IV, hyperglycemia was observed in late lactation and decreased after weaning. Average concentrations of HbA1C reached values from 3.64 to 5.17%. HbA1C is a useful test for monitoring glycemic control that is why the presented research should be continued due to the lack of reference values in case of HbA1C in minks, which can contribute to making the diagnosis and help in confirmation or exclusion of diabetes. <![CDATA[Live weight and body measurements of male and female native ducks raised in different raising systems]]> ABSTRACT The purpose of this study was to determine live weight and body measurements of male and female native ducks raised in different raising systems. One hundred and twenty native ducks (60 males, 60 females) were used in the study. The ducks were raised in deep litter floor and cage systems. Live weight and body values were measured every two weeks, until they were 56 days old. Three-parameter logistic regression and Gompertz model were used to determine growth model of male and female ducks. Interactions of time-raising system and time-sex were statistically significant in terms of live weight. At the end of eight weeks, live weights of ducks raised in deep litter floor were higher than ducks raised in cage system. In addition, live weights of male ducks were higher than female ducks. Consequently, deep litter floor is more appropriate for live weight in native ducks. Accuracy rate of Three-parameter Logistic and Gompertz models for estimation of growth in ducks was between 0.91-0.95 and similar results were obtained from both models. The Gompertz model is appropriate for the data structure of this study because it contains fewer iterations than the Three-Parameter Logistic model. <![CDATA[Effects of sumac and turmeric as feed additives on performance, egg quality traits, and blood parameters of laying hens]]> ABSTRACT The objective of this study was to investigate the effects of sumac and turmeric on performance, egg quality traits, and blood parameters of laying hens. Forty Lohman Brown hens at 30 weeks of age were distributed into four groups, consisting of five replicates with two hens in each. The experiment lasted for 42 days. Laying hens were fed different basal diets in treatment groups and control groups. The groups consisted of hens fed a basal diet with 0.5% sumac, a basal diet with 0.5% turmeric, and a basal diet with 0.25% sumac + 0.25% turmeric. Hens were given ad libitum access to feed and water during the experiment. The results revealed that there were no statistically significant differences in terms of final body weight, egg production, egg weight, and feed intake after the groups were fed according to the diets as 0.5% sumac, 0.5% turmeric, and 0.25% sumac + 0.25% turmeric. Addition of turmeric increased egg production and egg weight, but reduced the feed conversion ratio compared with the control group. On the other hand, dietary supplementation with sumac decreased egg weight. Shape index, yolk index, albumen index, Haugh unit, and yolk color parameters were also not affected by dietary supplementation of turmeric and sumac. When layers were fed the 0.25% sumac + 0.25% turmeric-supplemented diet, yolk index was higher in number, but Haugh unit and albumen index were lower. Dietary addition of sumac and turmeric does not have any negative influence on performance and egg quality traits of laying hens. Dietary treatments do not significantly affect blood serum cholesterol, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels. With the supplementation of turmeric, AST and ALT levels are higher in number among all the groups. Dietary sumac and turmeric can be added at 0.5% level to laying hen rations without changing animal performance. <![CDATA[The role of yeast culture (<em>Saccharomyces cerevisiae</em>) on performance, egg yolk fatty acid composition, and fecal microflora of laying hens]]> ABSTRACT This study investigated the effects of different levels (0.05, 0.1, and 0.2%) of yeast culture supplementation on body weight, feed intake, feed conversion ratio, egg production, egg weight, egg quality traits, egg yolk fatty acid composition, and microbiological flora in feces. A total of 240 laying hens at 18-19 weeks of age were divided into four groups and fed a basal diet containing 2750 kcal/kg metabolizable energy and 16% crude protein for 16 weeks. The basal diet was supplemented with 0.05, 0.1, and 0.2% commercial yeast culture product obtained from Saccharomyces cerevisiae. The different levels of yeast culture supplementation to the diets did not statistically affect body weight change among the treatments. However, feed intake was lowest in the group fed 0.2% of yeast culture. The highest egg weights were obtained from the groups fed 0.1 and 0.2% yeast culture, when compared with control group. Regarding fatty acid composition, linolenic acid (C18:2 n6) was lowest in the group fed 0.2% yeast culture. However, yeast culture supplementation to the diet did not alter the microbial flora. Yeast culture (S. cerevisiae) supplementation to the diet of laying hens is beneficial for increasing feed intake and egg weight of laying hens without affecting the microbial flora in their digestive system. <![CDATA[Effect of different vitamin D<sub>3</sub> metabolites on intestinal calcium homeostasis-related gene expression in broiler chickens]]> ABSTRACT The purpose of this study was to investigate the effects of vitamin D3 metabolites 1α-hydroxycholecalciferol (1α(OH)D3), 25-hydroxycholecalciferol (25(OH)2D3), and 1,25-dihydroxycholecalciferol (1,25(OH)2D3) on growth performance, bone quality, and intestinal calcium homeostasis-related gene expression in broiler chickens. One-day-old broilers were fed a basal diet and basal diet containing different vitamin D3 metabolites. The body weight, feed intake, and feed conversion ratio in control and experimental broilers were measured to assess the growth performance, mineral levels, and bone breaking strength. The duodenum was used to assess calcium homeostasis-related gene expressions by quantitative reverse transcription-PCR. No statistically significant difference was found in growth performance, mineral deposition, or bone breaking strength in broiler chickens after three weeks feeding with vitamin D3. However, supplementation of vitamin D3 metabolites tended to improve feed conversion rate, bone mineral deposition, and breaking strength in broiler chickens. The results demonstrated that vitamin D3 metabolites significantly upregulated calcium homeostasis-related genes, including calbindin, β-glucuronidase, TRPV6, and Na/Pi IIb cotransporter, mRNA levels after 12 h of feeding. The vitamin D3 metabolite 1,25(OH)2D3 was the most effective at regulating calcium homeostasis-associated gene expression after 6 h of feeding. Dietary vitamin D3 metabolites may alleviate the development of TD in broiler chickens and these effects probably occur through regulation of intestinal calcium homeostasis-related gene expression. <![CDATA[Meat properties and fatty acid profile of swine fed cashew bagasse bran in qualitative food restriction program]]> ABSTRACT The purpose of this study was to evaluate the effects of qualitative dietary restriction diet on carcass characteristics, meat quality, fatty acid profile, and performance of finishing pigs fed diets containing cashew bagasse bran. Forty pigs (20 females and 20 males) with initial weight of 60.00±5.24 kg of body weight (BW) were used. The diets were formulated with corn, soybean meal, cashew bagasse bran, vegetable oil, and mineral and vitamin mixture for finishing pigs. The experimental design was in randomized blocks with five treatments and four replicates, with two animals per experimental unit, one of each sex. Parameters related to performance, carcass characteristics, meat quality, and fatty acids profiles were used. The treatments used in the experiment did not affect feed intake and daily weight gain; however, in relation to feed conversion, a linear effect was observed with the increase of cashew bagasse bran levels in the diet. The same effects were also observed in carcass yield, backfat thickness, and fat area. The meat:fat ratio increased linearly with the increase of fiber in the diet. The level of 22.5% of cashew bagasse bran in finishing pig diets is recommended. <![CDATA[The requirement of valine for gilts in the initial phase is not influenced by moderate levels of leucine]]> ABSTRACT The objective of this study was to evaluate the standardized ileal digestible (SID) valine and SID leucine levels on performance, backfat thickness, longissimus dorsi depth, and biochemical blood parameters of starting gilts. A total of 72 gilts, with initial weight of 15.16±1.15 kg, were distributed in a randomized block design in a 2 × 4 factorial scheme, comprised of two SID leucine levels (1.20 and 1.77%) and four SID valine levels (0.58, 0.73, 0.88, and 1.03%), with nine replicates and one animal per experimental unit. No interactions were observed for growth performance parameters. Final weight and average daily gain presented linear and quadratic effects. Setting data to the quadratic model associated with the Linear Response Plateau model, the optimal level of SID valine for average daily gain was achieved at 0.703%. A quadratic effect was also observed for average daily feed intake (ADFI), estimating the highest ADFI at 0.822% of SID valine. No branched chain amino acid (BCAA) effects were observed for backfat thickness, longissimus dorsi depth, and lean meat percentage. The interaction between levels of BCAA showed that the highest SID leucine levels (1.77%) provided a high plasma urea concentration only at low SID valine levels (0.58 and 0.73%). The SID valine requirement of starting gilts for a maximum average daily gain is achieved at 0.703%, corresponding to 9.72 g day−1, and is not affected by SID leucine levels currently used in conventional diets. <![CDATA[Digestible threonine for slow-growing broilers: performance, carcass characteristics, intestinal mucin, and duodenal morphometry]]> ABSTRACT Five experiments were conducted to estimate the digestible threonine requirements of slow-growing broilers: experiment 1, starter phase (days 10 to 28); experiment 2, grower I phase (days 29 to 49); experiment 3, grower II phase (days 50 to 69); experiment 4, finisher phase (days 70 to 84); and experiment 5, which was specifically conducted to determine the production of intestinal mucin over two periods (days 50 to 69 and 70 to 84). Different birds were used in all experiments. A completely randomized design with five treatments and four replicates was used. Treatments consisted of increasing the values of digestible threonine in the diet through basal feed supplementation with L-threonine (98.5%), which was added instead of cornstarch. The following values of digestible threonine were investigated: 0.622, 0.697, 0.772, 0.847, and 0.922% in experiment 1; 0.586, 0.662, 0.738, 0.814, and 0.890% in experiment 2; 0.570, 0.640, 0.71, 0.780, and 0.850% in experiments 3 and 5; and 0.520, 0.595, 0.670, 0.745, and 0.820% in experiments 4 and 5. The digestible threonine values presented quadratic effects on feed conversion ratio in experiments 1, 2, and 3. Digestible threonine values of 0.628 and 0.609% resulted in higher villus height and greater duodenal crypt depth, respectively. Digestible threonine values of 0.762, 0.767, and 0.733% may be recommended for the starter, grower I, and grower II phases, respectively, based on the best feed conversion ratio. In addition, a digestible threonine level of 0.694% may be recommended for the finisher phase based on the highest production of intestinal mucin. <![CDATA[Effects of White Roman gosling quality on their growth parameters, intestinal villus morphology, blood biochemistry, and nonspecific pathological lesions]]> ABSTRACT The purpose of this study was to investigate the effects of gosling quality on their growth parameters, intestinal villus morphology, blood biochemistry, and nonspecific pathological lesions from 0 to 4 weeks old. Seventy-two goslings were randomly distributed into 12 pens, with each pen containing three males and three females in a completely randomized design of two control variables, including healthy and weak goslings. Healthy goslings all shared the same characteristics, such as good features with no abnormalities and full absorption of yolk sac. Albeit lighter body weight (&lt;85 g/bird) and incomplete absorption of the yolk sac were found in the weak geese, no obvious disease was exhibited in them. Post mortem examination revealed that the incidence of nonspecific pathological lesions of the 4 week-old healthy and weak gosling groups were 25.0 and 50.0%, respectively. Nonspecific pathological changes of 4 week-old goslings in the liver, ileum, lung, and heart were 16.7, 12.5, 8.3, and 4.2%, respectively. The healthy goslings also had higher total cholesterol, high-density lipoprotein, and low-density lipoprotein than weak goslings. Separately raising weak goslings from 0 to 4 weeks old could increase the survival rate and reduce economic losses of feeding. <![CDATA[Effects of <em>in ovo</em> injection of lysine and methionine into fertile broiler (parent stock) eggs on hatchability, growth performance, caecum microbiota, and ileum histomorphology]]> ABSTRACT We investigated the effect of in ovo injection of lysine, methionine, or their mixture into fertile broiler eggs on hatchability, chick weight, growth performance, inner organ development, caecum total aerobic bacteria, E. coli, coliforms, Enterobactericaea, and ileal histomorphology of broilers. Three hundred fertile eggs obtained from 60-week-old Ross 308 broiler breeders were used. Before this study, a preliminary study was conducted to determine the optimal amino acid dose. Optimum amino acid dose was determined as 2 mg/0.2 mL. Before replacing hatching machine, eggs were weighed individually and numbered. On day 16 of incubation, these eggs were allocated to treatment groups: negative control (no injection), positive control (distilled water injection 0.2 mL), lysine (2 mg/0.2 mL), methionine (2 mg/0.2 mL), and lysine + methionine (1 + 1 mg/0.2 mL). The hatching window lasted 32 h. During hatching, chicks hatched in the first hour and the last 6 h were discarded from the study to ensure equal hatching time. After hatching, 120 one-day-old healthy chicks were divided into five treatment groups with three replicates, each including eight birds, for 21 days. These chicks were given a starter diet (3080 kcal/kg metabolizable energy and 22% crude protein) during the trial. The results showed that in ovo injection of lysine, methionine, and lysine + methionine did not affect relative chick weight, livability, growth performance, caecum microbiota, and ileal villi length and thickness. Lysine injection increased hatchability compared with the negative control and methionine-injected groups. Gastrointestinal weight increased in lysine-injected group compared with the negative control group. The in ovo injection of 2 mg/0.2 mL lysine have a positive effect on the hatchability of fertile eggs. <![CDATA[Phenotypic study of egg production curve in commercial broiler breeders using Compartmental function]]> ABSTRACT The objective of this study was to analyze the effect of environmental factors on egg production curve traits in broiler breeders. The weekly egg production records of birds collected from four different flocks were used to estimate the egg production curve parameters using the Compartmental function (y = A(1 − exp−b(t − d))exp−ct). The coefficient of determination (R2) obtained by the model was 0.98. Least squares analysis of variance indicated that the environmental factors such as hatchability and flock had significant effects on egg production curve traits. The highest correlation was observed between the weekly potential maximum yield and yield at the beginning of laying, whereas the lowest correlation was found between the weekly potential maximum production and production after peak yield. Associated factors with the increasing slope of egg production curves had a negative correlation with the decrease after peak. The correlation analysis showed that peak production had a negative and significant relationship with production towards peak and time to reach peak production, while there was a positive and significant correlation with the slope decrease after peak yield. The Compartmental function can be used as an alternative model to predict egg production traits in broiler breeders. <![CDATA[Effects of <em>Ananas comosus</em> leaf powder on broiler performance, haematology, biochemistry, and gut microbial population]]> ABSTRACT The objective of our study was to evaluate the effects of pineapple (Ananas comosus) leaf powder (PLP) on broiler performance. One hundred male broiler chicks (aged one day) were divided into five groups consisting of four pens as replicates, which were treated with basal diet (normal control); basal diet supplemented with 1, 2, and 3% PLP; or 50 mg/kg of zinc bacitracin (ZnB) as a positive control for 35 days. Body weights were significantly increased by 1.06, 5.67, 13.15, and 11.92%, respectively, and feed conversion ratios were decreased by 2.36, 8.49, 12.06, and 11.43%, respectively, in 1, 2, 3% PLP- and ZnB-supplemented groups, compared with the normal control group. Notably, the 2 and 3% PLP supplementations had beneficial effects on broiler performance, similar to that of the positive group. Haematological parameters, such as red blood count, haemoglobin, and haematocrit, were improved in the 3% PLP-supplemented group, but no significant differences in white blood count and its differential count were observed. The serum biochemical parameters, such as creatinine and blood urea nitrogen, were found to be decreased in the 2 and 3% PLP-supplemented groups, compared with the normal control group. Finally, 2 and 3% PLP supplementations dramatically decreased the caecal coliform and Escherichia coli populations, but increased the lactobacillus population. Taken together, our results suggest that PLP improves the performance of broilers and balances the gut microbial population. Therefore, PLP can be used as a supplement in the diet of broilers. <![CDATA[Effects of fennel seed supplementation of ration on performance, egg quality, serum cholesterol, and total phenol content of egg yolk of laying quails]]> ABSTRACT The objective of this research was to evaluate the effects of fennel seed (Foeniculum vulgare Mill.) supplementation of ration on performance, egg quality, and serum cholesterol of laying quails during an eight-week period. For this purpose, 96 quail (Coturnix coturnix japonica) of 16 weeks of age were evenly separated into one control group and three treatment groups. Each group was divided into four replicates, each containing six quail. The fennel seeds (Foeniculum vulgare) were added to the diets of the first, second, and third treatment groups at levels of 0.3, 0.6, and 0.9%, respectively. No significant effect of dietary fennel seed supplementation was recorded on body weight, feed intake, egg production, and egg weight. Feed efficiency (kg feed per kg egg) of the 0.6% treatment group was negatively affected by fennel seed supplementation; however, kilogram of feed:dozen egg ratio was not affected when compared with the control group. The effects of dietary treatments on shape index, albumen height, albumen index, Haugh unit, yolk index, yolk colour, blood cholesterol level, and total phenol content of egg yolk had no significance. Dietary fennel seed do not affect the egg quality and blood cholesterol level of laying quail. The amount of 0.3, 0.6, and 0.9% dietary fennel seed supplementation do not have any adverse effect on performance and egg quality of laying quail. <![CDATA[Effects of two sources of Mexican oregano oil on performance, blood profile, carcass variables, and meat of broilers]]> ABSTRACT The current study was conducted to investigate the effects of Mexican oregano essential oil (MOO) extracts from Lippia berlandieri Schauer (LBS) and Poliomintha longiflora Gray (PLG) on performance, blood profiles, carcass variables, and meat composition of broilers at slaugther. A total of 360 one-day-old Ross broilers were randomly distributed into four dietary treatments with six replicate pens per treatment and 15 birds per pen. The dietary treatments were: a basal diet (control), control + 0.40 g of LBS/kg of feed, control + 0.40 g of PLG/kg, and control + 0.40 g of LBS/kg + 0.40 g of PLG/kg. Results showed that linear, quadratic, and cubic effects of days were significant in the performance variables of broilers. The treatments with LBS and PLG maintained the broiler body weight without increasing feed intake and water intake when compared with the control group. Broilers given LBS+PLG and PLG had increased blood leukocytes, lymphocytes, low-density lipoprotein, and hot carcass yields. In meat composition, treatments with PLG and LBS+PLG presented similar breast protein content compared with the control treatment. Supplementation with these two MOO exhibits positive effects on broiler performance, blood profiles, carcass traits, and meat composition. These two MOO may be promising feed supplements as growth promoters and enhancers of meat quality in broiler production. <![CDATA[Influence of dietary fat sources and conjugated fatty acid on egg quality, yolk cholesterol, and yolk fatty acid composition of laying hens]]> ABSTRACT This study was conducted to investigate the effects of dietary fats (tallow [TO] or linseed oil [LO]) or conjugated linoleic acid (CLA), singly or in combination, on laying performance, yolk lipids, and fatty acid composition of egg yolks. Three hundred 50-week-old laying hens were given one of five diets containing 2% TO; 1% TO + 1% CLA (TO/CLA); 2% LO; 1% LO + 1% CLA (LO/CLA); and 2% CLA (CLA). Laying performance, egg lipids, and serum parameters were not altered by dietary treatments. Alpha-linolenic acid or long-chain ω-3 fatty acids including eicosapentaenoic and docosahexaenoic acids were elevated in eggs of laying hens fed diets containing LO (i.e., LO or LO/CLA groups) compared with those of hens fed TO-added diets. Dietary CLA, alone or when mixed with different fat sources (i.e., TO or LO), increased the amounts of CLA in egg yolks, being the highest in the CLA-treated group. The supplementation of an equal portion of CLA and LO into the diet of laying hens (i.e., LO/CLA group) increase both CLA and ω-3 fatty acid contents in the chicken eggs. <![CDATA[Effects of the buriti (<em>Mauritia flexuosa</em> L.) oil supplementation on crossbred lactating goats: behavioral, physiological, and hematological responses]]> ABSTRACT This study aimed to evaluate the buriti oil (Mauritia flexuosa L.) inclusion levels (0, 15, 30, and 45 g kg−1 in dry matter) replacing ground corn on the feeding behavior, as well as physiological and hematological variables of crossbred lactating Anglo Nubian goats. Eight Anglo Nubian goats were used, which were distributed in a double 4 × 4 Latin square experimental design (four periods and four levels of buriti oil) replacing corn in the total dry matter. For the evaluation of feeding behavior, single animals were observed every ten minutes for 24 h on three days. Respiratory rate (RR), heart rate (HR), rectal temperature (RT), and sweating rate (SR) of the animals were evaluated in the morning (09:00 h) and in the afternoon (15:00 h). Blood samples were always taken in the morning, before feeding, by puncturing the jugular vein for the complete blood count and white blood cell count. The levels of buriti oil had no effect on feeding, rumination, idling time, water intake, defecation and urination, DM intake, feed efficiency, and rumination efficiency of DM and NDF, but had effects on NDF intake. Physiological variables (RT, SR, RR, and HR) in both periods of the day were not influenced by the inclusion of buriti oil. However, SR and RR were higher in the afternoon than in the morning. In erythrocyte, results showed that the hematocrit and mean corpuscular volume increased with the inclusion of buriti oil. Hemoglobin, red blood cell count, mean corpuscular hemoglobin concentration, and total plasma protein were not affected by the inclusion of buriti in the goat diet. The inclusion of buriti oil is recommended in up to 45 g kg−1 (DM basis) as a replacement for ground corn in diet of lactating goats without affecting the feeding behavior and physiological and hematological variables. <![CDATA[Performance and carcass characteristics of lambs fed a solution of cheese whey during feedlot and pre-slaughter lairage]]> ABSTRACT The objective of this study was to evaluate performance and carcass and meat characteristics of lambs fed a solution of cheese whey plus water (100 g kg−1 dry matter) (CW) during feedlot and pre-slaughter lairage. Data were analyzed as a 2 × 2 factorial (place – feedlot and slaughterhouse, food – water or CW). We evaluated the following treatments (feedlot/slaughterhouse): CW/CW, CW/water, water/CW, and control (water/water). The lambs were given a balanced diet for 70 days in the feedlot. Slaughter started 12 h after the animals arrived at the slaughterhouse. Dry matter intake, gain-to-feed ratio, average daily gain, and body weight of lambs fed CW were similar to those of control lambs. The water/CW group consumed less of this solution than the CW/CW group in the slaughterhouse. The CW supplied as a pre-slaughter supplement reduces the drip losses of lamb carcasses provided that the animals also consume it during the feedlot period. The other carcass characteristics (carcass weight, pH, subcutaneous fat thickness, and ribeye area) were similar among treatments. The meat characteristics (color, water holding capacity, cooking losses, and shear force) were similar among treatments. Whey cheese added to water can be used as an ingredient of the diet for lambs and as pre-slaughter supplement, since it does not change performance and improves carcass characteristics. <![CDATA[Substitution of soybean meal for urea in diets based on deferred buffelgrass hay for feedlot sheep]]> ABSTRACT The objective of this study was to evaluate the effect of substituting soybean meal for urea in diets based on deferred buffelgrass on the performance of feedlot sheep. Thirty mixed-breed sheep with an average initial body weight of 17±1.5 kg were distributed in a completely randomized design in which the experimental treatments consisted of five diets with six replicates. Diets were composed of deferred buffelgrass plus concentrates and calculated to be isoproteic. Treatments were represented by the substitution of soybean meal for the urea levels (0, 25, 50, 75, and 100%). Nutrient intake did not differ among animals fed diets with urea levels. Hot and cold carcass weights, hot and cold carcass dressing percentages, initial and final pH, and weight of commercial cuts did not differ among animal fed diets with urea levels. There was no difference for non-carcass components among animals, except for the empty carcass, gall bladder, and perirenal fat weights, which were influenced by dietary urea levels. Substituting the crude protein from soybean meal for the protein from urea provides a similar performance in sheep consuming deferred buffelgrass. <![CDATA[Performance and carcass characteristics of lambs fed a solution of crude glycerin during feedlot and pre-slaughter lairage]]> ABSTRACT The objective of this study was to evaluate performance and carcass and meat characteristics of lambs fed a solution of crude glycerin plus water (100 g kg−1 of dry matter) (GLY) during feedlot and pre-slaughter lairage. Data were analyzed as a 2 × 2 factorial (GLY available or not in feedlot and GLY available or not in the slaughterhouse). We evaluated the following treatments (feedlot/slaughterhouse): GLY/GLY, GLY/water, water/GLY, and water/water (control). Lambs fed a balanced diet for 70 days in the feedlot. Slaughter started 12 h after the animals arrived at the slaughterhouse. Dry matter intake, feed conversion, average daily gain, and body weight of lambs fed GLY were similar to those of control lambs. Lambs receiving GLY ingested more water in the feedlot. At the slaughterhouse, water/GLY animals ingested more glycerin and water than GLY/water animals ingested water. Group GLY/GLY had lower drip loss in carcasses than the group GLY/water. The other carcass and meat characteristics (carcass weight, pH, subcutaneous fat thickness, ribeye area, color, water holding capacity, cooking losses, and shear force) were similar among treatments. Solution of crude glycerin plus water can be used as a dietary ingredient for lambs, since it improves hydration and does not change performance and carcass characteristics. This solution supplied as a pre-slaughter supplement does not improve carcass and meat characteristics. <![CDATA[Challenges of beef cattle production from tropical pastures]]> ABSTRACT The live weight gain of cattle on tropical pastures is reviewed and found to be low and dependent on the length of the growing season. Supplements may be added to address the primary limiting nutrient, which, in the dry season, is crude protein. The response relationships of live weight gain to level of supplement (protein or energy) that have been developed for animals on pasture in Brazil and Australia have been compared and found to be very similar. This gives confidence in recommending a supplementation strategy for cattle on tropical pastures. Response in the wet season was very low and likely to be uneconomic compared with dry season supplementation. Supplementation is costly and should only be used as a last resort, but the strategy needs to be viewed in the context of a growth path to a defined market or slaughter weight. In Australia, high inputs in the first dry season are risky as subsequent compensatory growth can reduce or eliminate the weight advantage of a supplement. There is less financial risk in using supplements towards the end of the growth path. Growth paths can follow many forms and there is no need to maximise live weight gain in each period. Targeted supplements in the second dry season, leucaena based systems, other special-purpose pastures or crops, and feedlots offer the most economical way for cattle to meet market targets. The expected annual live weight gain and weaning weight are other major factors which determine the growth path, target market which can be achieved, and the level of intervention (supplements, legumes, feedlots, etc) which are required and when. Some recent results on growth paths in Australia are presented. <![CDATA[Sheep meat commercialization in the retail market in Brazilian cities]]> ABSTRACT This paper explored the mix market characteristics of sheep meat as a product for sale in different cities in the states of São Paulo and Paraná. For this, 81 products were purchased in 21 outlets sampled in a “non-probabilistic” manner for convenience and then subjected to analysis of yield of meat, bone, and fat. Imported products represented 20% of the total, being marketed in hypermarkets. It was observed that 37% of the total products were obtained in hypermarkets, 31% in supermarkets, 23% in butcher shops, and 8.6% in meat outlets. Almost 9% of the products had not undergone the official slaughter inspection system. The main types of products identified were palettes and legs with bones (33.3 and 24.7%, respectively); however, only 25% were satisfactorily displayed to consumers. The yields obtained in meat and deboned portions were 74% and 59% of the total weight, significantly affecting the average adjusted sales prices of the products, respectively US$13.01/kg sale price; US$17.82/kg deboned; and US$22.52/kg lean meat. The low yield of clean and boned meat observed in the samples can lead to negative experiences of these products by consumers. <![CDATA[Problems of water buffalo breeding in Turkey and suggestions for its development]]> ABSTRACT The objective of the study was to present the current situation of water buffalo breeding in Turkey, determine the relevant problems, and propose suggestions for its improvement. The research data were collected at the “Focus Group Interviews” with the sector actors from the cities engaged in buffalo breeding between July and September of 2015. The cities included Afyonkarahisar, Bitlis, Diyarbakir, Istanbul, Muş, Samsun, and Tokat, where buffalo breeding was usually practiced by small-scale family enterprises that used traditional husbandry methods. The variables chosen as indicators of yield included milk yield, meat yield, and lactation period, which were found to be below global averages. The study revealed lack of adequate record-keeping of enterprises raising water buffalo. Buffalo breeders should take necessary steps to improve their strategies to increase buffalo milk yield, while government agencies should protect wetlands and prevent their unintended use, making relevant legal arrangements where necessary. Buffalo meat and milk should be promoted with an emphasis on their superior nutritional values. For the development of buffalo breeding in Turkey, necessary steps should be taken on both national and local levels. <![CDATA[Identification of risk factors affecting production of beekeeping farms and development of risk management strategies: A new approach]]> ABSTRACT The aim of this investigation was to determine risk factors affecting production of beekeeping farms in Igdir province of Turkey and to develop strategies in coping with these risks. Research was based on data collected through a questionnaire applied to 85 beekeeping farms registered to Igdir Beekeepers’ Union according to exact counting method. Factor analysis was applied to collected data to identify risk factors and risk management strategies. Factor analysis was conducted under principle component extraction method and VARIMAX rotation. A stepwise regression analysis was used to reveal the relationship between each of four strategy factors and eight risk factors. As risks in procuring labor occur, farmers are more likely to adopt modern agricultural techniques and risk management strategies, such as registering to a cooperative, product insurance, contract farming, and cooperating with public bodies. Unfavorable security conditions and lack of proper bookkeeping in farms are more likely to lead to adoption of careful production and investment planning. As enterprise conditions get better or external conditions get worse, protecting the investment through disease-prevention and better marketing through getting more market information becomes important. Thus, thirteen applicable strategies are determined in the study. As a result, the approach developed in this research could be suggested for beekeepers in selecting necessary strategies against possible risk factors defined here for sustainable honey production and more income.