Scielo RSS <![CDATA[Revista Brasileira de Zootecnia]]> vol. 45 num. 12 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[Stability of enzyme complex solid-state fermentation subjected to the processing of pelleted diet and storage time at different temperatures]]> ABSTRACT The effects of processing of pelleted diets and their storage time on the stability of the enzyme complex SSF (solid-state fermentation) were evaluated. Two diets were formulated with the same nutritional composition, differing only in the Schizochytrium sp. levels (0 g kg-1 and 50 g kg-1). The samples were collected during the following processing steps: mixing, then pelleting, and then oven. To evaluate the storage time, the diet ready after drying was considered as day 1. On this day, two samples were obtained, being one kept in a room with ambient temperature of 25 °C and another stored in freezer at -18 °C. At 15, 30, 45, and 60 days, sub-samples were taken. All samples from the processing step and storage time were sent to the laboratory and the following enzyme activities were measured: α-galactosidase, endoglucanase (carboxy-methyl-cellulase), xylanase, sucrase, amylase, lipase, and trypsin. There were no significant differences between the mixture and post-oven phase, except for the activity of α-galactosidase, lipase, and sucrase. For the storage temperature of 25 °C, no effect was observed for the activities of endoglucanase, sucrase, xylanase, amylase, and trypsin between the first (after oven) and the 60th day of the trial. As for the storage temperature of -18 °C, no difference was observed, except for the activities of endoglucanase and xylanase between the first and last day. Comparing the two types of storage (25 °C and -18 °C), there was difference only for the activity of galactosidase and trypsin at 60 days. The enzymes of the enzyme complex SSF studied remain stable during the processing of pelleted diet at 55 °C, maintaining activity for at least 60 days when stored at temperatures up to 25 °C. <![CDATA[Adjustment of four growth models through Bayesian inference on weight and body nutrient depositions in laying quail]]> ABSTRACT An experiment was conducted to estimate the parameters of the Gompertz, Brody, Logistic, and Von Bertalanffy equations through Bayesian inference and evaluate the potential for growth in terms of weight and body composition of laying female quail (Coturnix coturnix japonica). The weights and body compositions of the birds were obtained weekly (1-119 days), allowing the adjustment of the four equations by Bayesian inference. The parameters mature weight (β1), integration constant (β2), maturity rate (β3), and their credibility intervals in four models on body weight and body components were properly estimated by Bayesian inference to describe the body growth in laying quail. The inflection point was determined by the 1st and 2nd derivatives of the Gompertz equation for body weight and body components (fat, protein, ash, and water). Based on Deviance Information Criterion (DIC) for the studied and analyzed variables, there is a model that fits best as a result of its better performance to achieve the DIC value. The Von Bertalanffy model proved to be very versatile, not obtaining good fit of data only for fat. The study shows that other models can also be used in several data sets as an alternative to Gompertz, which, due to its adequate biological interpretation and desirable characteristics in a curve growth, is generally the most used. <![CDATA[Assessment of a natural, non-antibiotic blend on performance, blood biochemistry, intestinal microflora, and morphology of broilers challenged with <strong><em>Escherichia coli</em></strong>]]> ABSTRACT The effect of a non-antibiotic growth-promoting component composed of natural phytomolecules, direct-fed microbials, glucomannan oligosaccharides, and organic acids on the performance, intestinal morphology and microbiology, plasma biochemistry, enzyme activities, visceral organ weights, and immune response of commercial broilers challenged with Escherichia coli was investigated. Three hundred and sixty one-day old male Ross 308 broiler chicks were randomly divided into basal diet (control, CON); control plus 0.5 mL of culture materials containing 108 cfu/mL of E. coli (E. coli); control with 400 mg/kg bacitracin methylene disalicylate (an antibiotic growth promoter, AGP); control plus 1000 g/t of feed of a blended mixture of natural feed additives (NAT); combination of E. coli and AGP treatments (E. coli + AGP); or the combination of E. coli and NAT treatments (E. coli + NAT). E. coli injection decreased broiler performance by lowering body weight and increasing feed intake, whereas AGP and NAT treatments improved body weight and the feed efficiency when compared to the other groups. However, feed intake was not affected by treatment. Immune response also improved with the addition of NAT, compared with control. Blood biochemistry parameters were significantly affected by the treatments. Nutrient digestibilities were increased by AGP and NAT supplementation in E. coli-challenged groups. Both AGP and NAT significantly decreased E. coli and coliform numbers in ceca. Ileal villus height was not affected by treatment, but ileal crypt depth and goblet cell counts decreased in the NAT relative to control group. Antibiotic growth promoter was somewhat more effective in improving broiler growth and health characteristics than NAT, but since NAT generally improved broiler performance compared to the control group, it can be alternatively used as an alternative to AGP in commercial broiler production. <![CDATA[Effect of soybean hulls on blood biochemical profiles and body condition of dogs]]> ABSTRACT The objective of this study was to evaluate the alterations in blood biochemical profiles and body condition of dogs after intake of the diet without soybean hull (0%SH) and with soybean hull (16%SH) replacing corn. Twelve Beagle dogs with ideal body condition score (BCS) (average: 5) were distributed in a completely randomized design (six animals per treatment) and received the daily amount of food according to the energy needs for maintenance (g/kg weight0.75). The animals were evaluated on days 0 and 28 in relation to the blood biochemical profiles and body measurements, such as: total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low density lipoprotein (VLDL), triglyceride (TAG), glucose, body weight (BW), body fat percentage (%BF), nape, rib, tail base (TB), chest, and abdomen with plicometer, and BCS (scale of 1, thin and 9, obese), canine body mass index (CBMI), and thickness of the adipose tissue of the seventh lumbar vertebra (L7) with ultrasonography. The data were analyzed by Student's t test. The variation (final - initial, mg/dL) of cholesterol (16.33 vs. 15.55), HDL (17.56 vs. 10.05), LDL (22.78 vs. 14.57), VLDL (-4.01 vs. -1.92), TAG (-20.11 vs. -11.66), and glucose (-16.77 vs. -20.31) of dogs fed 0%SH and 16%SH, respectively, showed no difference. The body measurement variation (cm) of TB (1.00 vs. -0.60) obtained a significant difference. The addition of soybean hull in the diet does not alter the blood biochemical profiles; however, it does decrease the deposition of lipids in subcutaneous tissue. <![CDATA[Performance and methane emissions of Nellore steers grazing tropical pasture supplemented with lipid sources]]> ABSTRACT The objective of this study was to evaluate the effect of lipid sources on voluntary intake, digestibility, performance, and CH4 emission of Nellore steers grazing Brachiaria brizantha cv. Xaraés forage in the dry season. Forty-five Nellore steers with average weight of 442±34 kg were alloted into one of the five treatments: without additional fat; with palm oil; with linseed oil; with protected fat; and with whole soybeans. The supplements were provided daily and quantities were adjusted to 1% of body weight and diets were formulated in accordance with the Cornell Net Carbohydrate and Protein System. The experimental design was completely randomized with five treatments and two replications. There were no effects on dry matter, organic matter, and neutral detergent fiber intake with the inclusion of lipids in the diet. The neutral detergent fiber showed decreased digestibility in animals receiving linseed oil and palm oil treatments compared with animals receiving the diet without additional fat. The linseed oil treatment reduced CH4 emissions by 38% when expressed in mg/d/kg BW and tended to reduce the emission in g/d/kg BW0.75. Lipid sources did not affect the weight gain of the animals. The intake and performance of grazing Nellore steers supplemented at 1% body weight with lipid sources were not modified. However, fiber digestibility was reduced with palm or linseed oil addition. Linseed oil reduced enteric CH4 emissions. Linseed oil has the potential to reduce enteric CH4 emissions in continuous tropical grazing systems based on B. brizantha grass. <![CDATA[Performance and eating behaviour of crossbred goats in Mediterranean climate of Turkey]]> ABSTRACT The objective of the study was to investigate milk yield and eating behaviour of crossbred goats, German Improved Fawn × Hair crossbred (GIF) and Saanen × Hair goats (S), in subtropical eastern Mediterranean climate of Turkey during early summer season. Eight GIF and eight S goats were individually housed in 1.5 × 1.5 m pens. Diurnal eating patterns were monitored by a system that recorded meal size and meal length. Milk yield (kg/day) was 1.77 in GIF and 2.0 in S goats, whereas milk production efficiency (kg feed/kg milk) was 1.15 in GIF and 1.07 in S goats. The differences between GIF and S goats in eating behaviour parameters were significant: the S goats had higher meal size and meal length and longer inter-meal interval, meal time, and eating rate within in each meal, but lower number of meals in comparison with GIF goats. German Improved Fawn × Hair crossbred and Saanen × Hair goats have similar lactation performance under good nutritional condition, but their eating behaviours are quite different. <![CDATA[Degradability and kinetics of fibrous particles in cattle fed diets based on corn silage and concentrates with or without addition of lipids]]> ABSTRACT Eight rumen-cannulated steers were assigned to two 4 × 4 balanced Latin squares to evaluate degradability and kinetics of fiber particles from diets based on corn silage and supplements with or without addition of lipids. Dietary treatments were: only corn silage (T1), corn silage plus concentrate with no added lipids (T2), corn silage plus concentrate with added soybean oil (T3), and corn silage plus concentrate containing ground soybean seeds (T4). Kinetics of gastrointestinal transit of fibrous particles was evaluated based on chromium-mordanted fiber. Events of rumen degradation dynamics of fibrous carbohydrates were quantified using the in situ incubation procedure. The mixed models methodology from SAS was used to fit models and the Tukey test was used to compare means. The ruminal digestibility of fiber was lower in treatments T3 and T4 and, consequently, lower proportions of potentially digestible fraction of standardized fiber and higher proportions of indigestible fraction of standardized fiber for treatments T3 and T4 compared with T1 and T2 were observed. However, there were no differences in mean retention time of the rumen, total mean retention time, mean digestion time, and rumen fill among diets. Animals from T2, T3, and T4 showed higher dry matter intake, organic matter intake, and crude protein intake rates than animals receiving T1 diet, but there was no effect of the addition of lipid. Treatments did not differ regarding neutral detergent fiber intake. Animals from T1 had lower crude fat intake than animals from T2, which showed lower crude fat intake than those from T3 and T4. The addition of lipid to concentrate has no effect on passage rate, digestion rate, and intake, when a good quality roughage is used. <![CDATA[Effects of feed restriction and forage:concentrate ratio on digestibility, methane emission, and energy utilization by goats]]> ABSTRACT This study was carried out to to evaluate how feed restriction and different forage:concentrate ratios affect digestibility, methane emission (using the SF6 technique), and energy utilization of Anglo-Nubian goats. Fifteen (15) dry and non-pregnant Anglo Nubian goats, averaging 30±2.9 kg body weight, were used. The experiment was divided into two trials, the first of which was designed to study the effects of feed restriction (0% or ad libitum; 15% of feed restriction or equivalent to 85% of ad libitum intake; and 40% of feed restriction or equivalent to 60% of ad libitum intake) and the second, to study the effects of forage:concentrate (F:C) ratios (75:25, 54:46, and 25:75) in the diet. The sulfur hexafluoride (SF6) tracer gas method was used to collect and estimate methane (CH4) emissions. Feed restriction level did not affect apparent total tract digestibility of dry matter (DM), organic matter, crude protein, and neutral detergent fiber. Methane emission (g d−1) decreased linearly as intake level decreased. However, energy loss in methane proportional to organic matter intake was similar among levels of feed restriction; consequently, dietary metabolizability did not differ among treatments. Methane gas (g d−1) as a function of F:C ratio revealed a quadratic response, showing the highest values when animals were fed the 46:54 F:C ratio diet (18.2 g d−1), suggesting that the decrease in absolute CH4 occurred when the level of concentrate inclusion in the diet surpassed approximately 50%. The results presented herein may be relevant for the ongoing and future efforts towards completion of an IPCC inventory regarding the contribution of goats to the greenhouse gas effects on the planet. <![CDATA[Risk analysis and probability of return on invested capital in an intensive beef cattle production system in Minas Gerais, Brazil]]> ABSTRACT The study evaluated the average return on invested capital (ROIC) in function of the variations in the historical prices of beef cattle and the odds of return on that capital gain within the system of beef cattle fattening on a farm in the state of Minas Gerais, Brazil, from 2004 to 2007. To calculate the risk of ROIC, monthly data of beef cattle prices (BM&amp;F) were used from July 1997 to December 2013, revised by the General Price Index of the Fundação Getúlio Vargas in December 2013. The corrected data were divided into five classes that correspond to the risk scenarios. In light of these classes, the observed frequencies and their respective probabilities were calculated. The cumulative and updated ROIC were -3.02 and 0.24%, respectively. The odds for obtaining returns above 8.4% (Brazilian Selic Rate) per year were median, corresponding to 32.0 and 34.94% for the calculation of operating profit (ROIC OP) and total profit (ROIC TP), respectively. The expected average annual return was 6.26 and 7.66% for ROIC OP and ROIC TP, respectively. The standard deviation and coefficient of variation showed a high risk of ROIC because the scale and extent of dispersion per unit of expected return were elevated in the accumulation period and the risk for 2013 was reduced according to the price of beef cattle. The expected risk of ROIC was considered high between 2004 and 2007 and average for 2013. The probability of return on capital invested in the intensification of fattening beef cattle is a function of the selling price of cattle and purchase of inputs, in which the high scenario ranching provides greater probability of getting a return above the bank interest rates. <![CDATA[Value of genomics in breeding objectives for beef cattle]]> ABSTRACT The objective of this research was to discern the contribution of genomic information to multiple-trait breeding objectives and thus understand the economic value of that information. True genetic values were simulated for each of n, possibly correlated, traits. These true genetic values, combined with uncorrelated random noise, resulted in both genomic and phenotypic estimated breeding values, EBVg and EBVp, respectively. The separate EBV were then merged (blended) as a function of their respective accuracies to produce a unified EBV for each of the n traits. Finally, for each simulated animal (N = 10000), the sum of products of economic weights and EBV was calculated to predict the economic value (net merit) of the individual. Accuracies of the EBV for the individual traits and net merit were calculated as correlations between predicted and true values. Predicted responses to selection for individual traits included in the breeding objectives were enhanced from 9% to 76% with the greatest benefit accorded to those economically relevant traits that are recorded after selection decisions are made at one year of age, measured less frequently in national cattle evaluation, or often predicted using information from indicator traits. Combining the EBV to predict net merit for terminal and maternal breeding objectives resulted in predicted increases in selection response due to incorporation of genomic information of 27% and 57%, respectively. The results are interpreted to suggest that the economic benefit to be derived from selection based on a multiple-trait economic breeding objective, which is predicted using genomically enhanced EBV, can substantially exceed the present day cost of genotyping the candidates for selection.