Scielo RSS <![CDATA[Revista Brasileira de Zootecnia]]> http://www.scielo.br/rss.php?pid=1516-359820170003&lang=pt vol. 46 num. 3 lang. pt <![CDATA[SciELO Logo]]> http://www.scielo.br/img/en/fbpelogp.gif http://www.scielo.br <![CDATA[Presence of roosters in an alternative egg production system aiming at animal welfare]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300175&lng=pt&nrm=iso&tlng=pt ABSTRACT The objective of this study was to evaluate the effect of the presence of roosters on welfare and egg production of laying hens reared in an alternative system. Two breeding systems were established: barn 1 - laying hens reared without roosters (4500 birds); and barn 2 - laying hens reared with roosters (4500 layers and 250 roosters). In the poultry facilities, microclimate, egg production, mortality rate, and bird behavior were evaluated. Microclimate analysis showed that the birds were subjected to periods of constant heat stress, except for the morning hours. However, even under these conditions, egg production results and mortality rate were consistent with the indices recommended in the Isa Brown management guide in the barn with roosters; the indices obtained were even better and were characterized by higher egg production and lower mortality rates. In addition to productivity benefits, the presence of roosters broadened the behavioral repertoire of the birds due to the introduction of reproductive behaviors. Moreover, there was a significant decrease in the tolerance-reflex behavior, which is associated with the impossibility of displaying reproductive behaviors. This alternative egg production system proved to promote animal welfare since it provides and stimulates the display of behaviors considered important for birds. <![CDATA[Determination of the mode of reproduction of bahiagrass hybrids using cytoembryological analysis and molecular markers]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300185&lng=pt&nrm=iso&tlng=pt ABSTRACT The aim of this study was to determine the mode of reproduction of a hybrid progeny derived from intraspecific crosses of Paspalum notatum through cytoembryological analysis and use of RAPD (random amplification of polymorphic DNA) molecular markers. Cytoembryological analysis allowed identification of the mode of reproduction of 28 plants that were selected after agronomic productivity evaluations. Of these, 19 had embryo sac morphology compatible with an apomictic mode of reproduction and nine had embryo sac morphology compatible with a sexual mode of reproduction. Meanwhile, molecular marker analysis for 194 individuals showed 54 sexual and 140 apomictic plants; of the 28 plants analyzed by the two methods, ten results (35.7%) were in disagreement. In this paper, through cytoembryological analyses, a ratio of 1:2.1 of sexual to apomictic plants was found. The BCU 243 marker showed a stable pattern of amplification, but some results differed with cytoembryological analyses, demonstrating that these analyses are more reliable when determining the mode of sexual reproduction for the plants of P. notatum. Apomictic plants characterized in this work can be tested in the field to check their agronomic value and registration as plant varieties, while the sexual plants can be used as potential parents in future crosses. <![CDATA[Seasonal variation in the reproductive activity of male goats raised under tropical climate conditions]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300192&lng=pt&nrm=iso&tlng=pt ABSTRACT This study analyzed seasonal variations in the testes, the concentration of sex hormones, the parameters of fresh and thawed semen, and the sexual behavior of male Alpine goats from a temperate region in a tropical climate and possible interference with fertility. The maximum and minimum temperature and luminosity were recorded daily, while seminal, hormonal, and behavioral assessments were carried out every fortnight. The maximum and minimum temperature (°C) and luminosity (h) were recorded daily always at 17.00 h. The scrotal circumference (cm), testicular volume (mL), volume (mL), appearance (creamy, milky, aqueous) and coloration (white, white-yellowish, and yellowish) seminal, turbulence or mass movement (0 to 5), progressive spermatic motility (0 to 100%), spermatic force (0 to 5), concentration (spermatozoids/mL), spermatic pathologies, hypoosmotic test (%), serum levels of FSH (mUI/mL), LH (mUI/mL), testosterone (ng/mL), and sexual behaviors were carried out every fortnight. There was a difference between the scrotal circumference evaluated monthly, testicular volume, volume and concentration of fresh semen, sperm vigor of the thawed semen, serum levels of testosterone, FSH and LH, and some sexual behaviors. Thus, the changes that occur in the quantity and quality of sperm, in the hormonal profile, and in sexual behaviors should not be regarded as an impediment to the use of male Alpine goats in tropical climates throughout the year. These variations do not lead to changes in the semen that may compromise the fertility of these animals. <![CDATA[Effect of photoperiod length and light intensity on some welfare criteria, carcass, and meat quality characteristics in broilers]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300202&lng=pt&nrm=iso&tlng=pt ABSTRACT The objective of this study was to investigate the effects of photoperiod length and light intensity on leg and eye health, tonic immobility, some blood parameters, carcass, and meat quality characteristics in broilers. A total of 272 one-day-old male broiler chicks (Ross 308) were randomly assigned to four treatment groups based on the photoperiod length (23L:1D or increasing duration of light) and light intensity (20 lux vs. dim light) with four replicates. In this study, photoperiod lenght had no effect on incidence of foot pad and hock burn. On the other hand, the effect of photoperiod lenght had significant influence on the gait score. The incidences of gait score (3 + 4 + 5) in bright and dim light groups was found as 21.4 and 41.0% in broilers, respectively. In addition, the effect of light intensity had statistical significance on gait score. The tonic immobility duration in 20 lux and dim light groups were 271.53 and 226.78 s, respectively, and tonic immobility duration was unaffected by light intensity. All the blood parameters, except for triglyceride, were not affected by light intensity. The dim light had a negative effect on broiler welfare as demonstrated by increased eye weight and dimensions. Cold carcass yield and whole breast and wing yields were lower in the dim light group than in 20 lux light intensity. The broilers kept with dim light had lower breast meat ultimate pH (6.19) and L* values (54.30) than those reared with 20 lux. These findings have a lot of implications on the use of increasing photoperiod and bright light to improve leg an eye health benefits for the broiler welfare in broilers. <![CDATA[Glycerin levels while maintaining the electrolyte balance in finishing pig diets]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300211&lng=pt&nrm=iso&tlng=pt ABSTRACT The objective of this study was to evaluate performance and carcass and meat characteristics of finishing pigs fed diets with different levels of glycerin, while maintaining the electrolyte balance. Forty barrows with an initial weight of 97.76±13.44 kg were distributed, in a randomized block design, into four treatments with five replicates. Treatments consisted of diets containing 0, 5, 10, and 15% glycerin. Inclusions of salt and sodium bicarbonate were adjusted to balance the sodium content and maintain the same electrolyte balance of the diets as a function of glycerin inclusions. In vivo backfat thickness, daily feed intake, daily weight gain, and feed conversion were measured. After the animals were slaughtered, pH and temperature were measured 45 min and 24 h postmortem, and backfat thickness, loin-eye area, drip loss, and colorimetry were determined. Glycerin inclusion levels did not influence the performance of barrows. Hot carcass weight, dressing percentage, and lightness had higher values when pigs were fed diets containing 2.32, 2.43, and 2.61% glycerin, respectively. The other carcass and meat characteristics were not influenced. Glycerin can be used in finishing pig diets without compromising results of performance or carcass and meat characteristics up to the inclusion level of 15%. <![CDATA[Glutamine supplementation plans for broilers reared in high-temperature environments]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300218&lng=pt&nrm=iso&tlng=pt ABSTRACT The purpose of this study was to evaluate the effect of glutamine supplementation plans on performance, carcass yield, and cut yield of broilers reared in a high-temperature environment. A fully randomized design was adopted for the experiment, comprising 900 male Hubbard broiler chicks assigned to five treatment groups (0% glutamine from one to 42 days of age; 0.5% glutamine from 1 to 7 days of age, followed by 0% from 8 to 42 days; 1.0% glutamine from 1 to 7 days of age, followed by 0.5% from 8 to 14 days and 0% from 15 to 42 days; 1.5% glutamine from 1 to 7 days of age, followed by 1.0% from 8 to 14 days, 0.5% from 15 to 21 days, and 0% from 22 to 42 days; 2.0% glutamine from 1 to 7 days of age, followed by 1.5% from 8 to 14 days, 1.0% from 15 to 21 days, and 0% from 22 to 42 days), consisting of six replicates of 30 animals each. The experiment was composed of four periods: pre-starter (1-7 days), starter (8-21 days), grower (22-33 days), and finisher (34-42 days). Glutamine supplementation plans up to 21 days do not improve the performance of broilers in the periods from 1 to 21 and from 1 to 42 days of age reared in a high-temperature environment. Carcass yields and cuts of broilers at 42 days of age are not changed by glutamine supplementation for up to 21 days. <![CDATA[Methionine + cystine levels and vitamin B<sub>6</sub> supplementation on performance and enzyme expression of methionine metabolism of gilts from 75 to 100 kg]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300223&lng=pt&nrm=iso&tlng=pt ABSTRACT This study was carried out to evaluate the effect of different levels of standardized ileal digestible (SID) methionine + cystine (Met+Cys) and vitamin B6 supplementation on the performance, blood variables, and gene expression of enzymes involved in methionine metabolism in female pigs between 75 and 100 kg. Fifty six female pigs were used (Talent × Topigs 20), averaging 75.06±1.68 kg in initial weight, allotted in a completely randomized block design arranged in a 2 × 4 factorial scheme, composed of two vitamin B6 supplementation levels (1.58 and 3.58 mg/kg) and four levels of SID Met+Cys (0.370, 0.470, 0.570, and 0.670%), with seven replicates and one animal per experimental unit. No interactions between vitamin B6 supplementation and SID Met+Cys levels were observed. The levels of SID Met+Cys and vitamin B6 supplementation did not affect animal performance. Triacylglycerols showed a quadratic response to the SID Met+Cys levels, in which the lowest plasma concentration was estimated as 0.575%. Treatments did not affect the expression of the methionine synthase and cystathionine-γ-lyase enzymes or serum homocysteine levels. The SID Met+Cys requirement for female pigs from 75 to 100 kg is equal to or lower than 10.60 g/day, which corresponds to the level of 0.370% Met+Cys in the diet and a relationship 0.48% with the SID lysine. <![CDATA[Trace mineral requirements for growth of Moxotó goats grazing in the semiarid region of Brazil]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300231&lng=pt&nrm=iso&tlng=pt ABSTRACT A comparative slaughter trial was conducted to estimate the body composition and net requirements of Cu, Zn, Mn, Fe, and Co for growth of castrated Moxotó goat kids, with15.69±0.78 kg initial body weight (BW), grazing in the semiarid region of Brazil. The baseline group consisted of four randomly selected kids (15.37±0.30 kg BW). Thirty-two kids were randomly allocated into eight groups (considered as block), distributed among four levels of concentrate supplementation (0, 0.5, 1.0, and 1.5% BW). Animals in a group were slaughtered when the 1.5% BW treatment kids in the group reached approximately 25 kg BW. The trace element content (mg/kg of empty body weight) ranged from 23.68 to 27.81 mg Zn, 35.70 to 47.29 mg Fe, 0.86 to 1.09 mg Mn, 1.45 to 1.75 mg Cu, and 0.83 to 0.87 mg Co for Moxotó kids at 15 and 25 kg BW, respectively. The net requirements (mg/kg of empty body weight gain) ranged from 30.43 to 35.74 mg Zn, 53.48 to 70.84 mg Fe, 1.22 to 1.54 mg Mn, 1.93 to 2.32 mg Cu, and 0.91 to 0.95 mg Co for animals with BW ranging from 15 to 25 kg, respectively. Indigenous goats grazing in the semiarid region of Brazil have different requirements from those values recommended by international committees for dairy and meat goats. <![CDATA[Additives on <em>in vitro</em> ruminal fermentation characteristics of rice straw]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300240&lng=pt&nrm=iso&tlng=pt ABSTRACT The objective of this study was to evaluate the effects of mineral and protein-energy (MPES), exogenous fibrolytic enzyme supplements (ES), combination of MPES + ES, and straw without supplement (WS) on digestibility, fermentation kinetic parameters, cumulative gas production, methane, CO2 production, and volatile fatty acid concentration of rice straw of low and high nutritional value, estimated by in vitro techniques. The experimental design was randomized and factorial 2 × 4: two straws (low and high nutritional value) incubated with four supplements (MPES, ES, MPES + ES, and WS) and their interactions. Four experimental periods were used, totaling four replications per treatment over time. Data were analyzed by PROC MIXED of SAS. The in vitro dry matter and organic matter digestibilities of the rice straw with high nutritional value was improved by MPES, while the combination of MPES + ES supplements inhibited the digestibility of this straw. Dietary carbohydrate and nitrogen increased through MPES and MPES + ES supplements resulted in an increase in NH3-N concentration and a decrease in CO2 production due to the microbial mass formation. However, this increase was not enough to improve organic matter degradability parameters, cummulative gas production, gas production kinetics, and acetate:propionate ratio and reduce methane emissions. The straw with high nutritional value showed greater content of nitrogen fraction a, effective degradability, cummulative gas production, and methane and CO2 productions comparing with low-nutritional value straw. The use of MPES and MPES + ES supplements can be used as strategy to mitigate CO2 in ruminant production systems that use rice straw. <![CDATA[Effects of macauba cake on profile of rumen protozoa of lambs]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300251&lng=pt&nrm=iso&tlng=pt ABSTRACT The present study was conducted to determine the effects of the inclusion of macauba cake, from biodiesel processing, on profile of rumen protozoa of Santa Ines lambs. Twenty-four lambs were randomized in block design supplemented with macauba cake at 0, 100, 200, and 300 g/kg of dry weight of the diet. Concentrations of small, medium, and large protozoa had quadratic relationships with inclusion of macauba cake, with maximum protozoa occurring at 100 g/kg. High genus diversity occurred in rumen fluid of lambs that did not feed macauba cake, comprising 13 protozoa genera. However, only the genera Isotricha, Charonina, Entodinium, Diplodinium, Eodinium, Diploplastron, and Polyplastron were detected in lambs fed 300 g/kg macauba cake, indicating that these protozoa were resistant to the effects of the cake. Addition of macauba cake levels greater than 100 g/kg show antiprotozoal effect in the rumen. <![CDATA[Characteristics of carcass and of non-carcass components of lambs and hoggets fed high-concentrate corn or sorghum diets]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300257&lng=pt&nrm=iso&tlng=pt ABSTRACT The objective of this study was to evaluate the characteristics of carcass and non-carcass components of lambs and hoggets finished in the feedlot with high-concentrate corn or sorghum grain-based diets. Thirty-two animals were finished, comprising 16 lambs (milk teeth) and 16 hoggets (two teeth), which were distributed in a completely randomized design in a 2 × 2 factorial arrangement (two sheep categories × two grains). For the variables final live weight, live weight at slaughter, hot carcass weight, cold carcass weight, hot carcass yield, cold carcass yield, carcass compactness index, subjective color, loin-eye area, fasting losses, external organs, internal organs, and for the weights, in kilograms, of neck, shoulder, ribs, and leg, there was a significant difference between categories. In the variables studied for the high-concentrate diets, significant differences were found for the ribs, expressed in relative values. Lambs have much higher fasting losses, a greater proportion of internal organs, and lighter-colored meat compared with hoggets. Hot and cold carcass yields, meat subjective color, and percentage of ribs are higher in feedlot-finished lambs and hoggets fed high-concentrate sorghum-based diets compared with those fed corn-based diets. <![CDATA[Characterization and influence of production factors on growing and finishing pig farms in Brazilian cooperatives]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300264&lng=pt&nrm=iso&tlng=pt ABSTRACT The objective of this study was to identify and quantify, through mathematical models, the main factors of production in growing and finishing pig units linked to three Brazilian cooperatives located in Western Region of Paraná State that influence the parameters of daily feed intake and feed conversion ratio. The records of 216 growing and finishing farms from 2010 to 2013, representing 1,533 batches, and totaling approximately 1,025,000 pigs, were evaluated. Thirty production factors related to the management, health, installations and equipment, nutrition, genetics, and environment were considered. The number of pigs per pen, the feeder model, the origin and sex of the animals, and the initial and final body weights were the factors included in the final models for both dependent variables (daily feed intake and feed conversion ratio) and had a significant impact on these ratios. Approximately, 41 and 55% of the total variance found for daily feed intake and feed conversion ratio, respectively, were explained by the variables included in the final models. Mathematical models could serve as important tools to aid the decision-making in pig production systems. <![CDATA[ERRATUM]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300273&lng=pt&nrm=iso&tlng=pt ABSTRACT The objective of this study was to identify and quantify, through mathematical models, the main factors of production in growing and finishing pig units linked to three Brazilian cooperatives located in Western Region of Paraná State that influence the parameters of daily feed intake and feed conversion ratio. The records of 216 growing and finishing farms from 2010 to 2013, representing 1,533 batches, and totaling approximately 1,025,000 pigs, were evaluated. Thirty production factors related to the management, health, installations and equipment, nutrition, genetics, and environment were considered. The number of pigs per pen, the feeder model, the origin and sex of the animals, and the initial and final body weights were the factors included in the final models for both dependent variables (daily feed intake and feed conversion ratio) and had a significant impact on these ratios. Approximately, 41 and 55% of the total variance found for daily feed intake and feed conversion ratio, respectively, were explained by the variables included in the final models. Mathematical models could serve as important tools to aid the decision-making in pig production systems.