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Itapetininga, Brazil

de Oliveira J.B.,Pos Graduacao em Zootecnia | Pires A.J.V.,DTRA UESB | Pires A.J.V.,Brazilian National Council for Scientific and Technological Development | de Carvalho G.G.P.,Federal University of Bahia | And 4 more authors.
Revista Brasileira de Zootecnia

The experiment was carried out to evaluate the intake, apparent digestibility and the milk yield of goats fed elephant grass silages containing industrial by-products. Eight Saanen breed goats were used, distributed in two 4 × 4 Latin squares, with four 14-day periods (ten days of adaptation and four days for data collection). The treatments were: elephant grass silage + concentrate; elephant grass silage containing 15% cassava meal + concentrate; elephant grass silage containing 15% coffee hulls + concentrate; elephant grass silage containing 15% cocoa meal + concentrate. The greatest intakes of dry matter (DM), organic matter (OM), total carbohydrates (TC), nonfiber carbohydrate (NFC) and digestible total nutrients were observed in the animals fed silage containing cassava meal. The greatest intake of ether extract was verified in the silages with cassava meal or coffee hulls. The greatest digestibility values of the DM, OM, EE and TC were obtained in the diet containing elephant grass silage with cassava meal. The NFC digestibility value was similar among diets containing elephant grass silage with cassava meal, coffee hulls and cocoa meal. The neutral detergent fiber and acid detergent fiber digestibility was greater in the silage without additive, with cassava meal or cocoa meal. Greater intake, digestibility coefficients and milk yield were obtained in goats fed elephant grass silage containing cassava meal. © 2010 Sociedade Brasileira de Zootecnia. Source

This study evaluated body development and reproductive performance of beef cows whose calves were submitted to early weaning (76 days of age), or conventional weaning (148 days of age). It was used 141 Braford cows that calved in 2004, 2005, and 2006 to evaluate weight at calving at 76 days, weight at calving at 148 days, weight at the beginning and end of the breeding season, variation of the average daily weight, body condition, pregnancy rate, and calving interval. Dams of calves weaned at 148 days of age showed daily weight gain higher body weight and better body condition at 148 days of age. The weights at the end of breeding season and average weight gain during the breeding season were higher in early weaning cows than in conventional cows. Pregnancy rate of early weaning cows (86.34%) was higher than those submitted to weaning at conventional age (55.45%). Pasture interval was similar among early weaning cows and conventional weaning cows. The best benefit on reducing weaning age in pregnancy rate was in primiparous cows. There was significant interaction between weaning age and the year for calving interval and milk production. The early weaning of calves carried out at 76 days of age allows cows to better weight recovery in the post-weaning and breeding periods, improving their body condition and consequently increasing pregnancy rate regarding to cows whose calves suckled until 148 days of age. © 2010 Sociedade Brasileira de Zootecnia. Source

Neto M.R.T.,Pos Graduacao em Zootecnia | da Cruz J.F.,UESB | Malhado C.H.M.,UESB | Carneiro P.L.S.,UESB | And 3 more authors.
Revista Brasileira de Zootecnia

The objective of this study was to characterize body biometrics of Santa Ines sheep during growth. Data from 4,038 animals, males and females, with ages from four to 36 months, from different herds participating in the National Agricultural Fair in Bahia from 2003 to 2008 were used. The characteristics evaluated were: body weight, average daily gain, body length, thoracic circumference, anterior height and posterior height. The mean values found were compared by the Student-Newman-Keuls test. All characteristics studied showed gradual change with aging, and it is worth-noting that age had positive effect on body weight, body length, thoracic circumference, anterior height and posterior height and negative effect on average daily gain. Average daily gain was reduced by 68.5% from four to 36 months of age, while the mean improvements observed in both sexes in this age range, for body weight, body length, thoracic circumference, anterior height and posterior height were 137.8%, 23.5%, 43.2%, 19.3% and 19.6%, respectively. However, the increments for body weight, body length and thoracic circumference were higher until 12 months of age, when an increase of 72.7%, 14.6% and 24.8% in their respective characteristics was verified. For anterior height and posterior height, the greatest increase occurred up to eight months of age with improvement of 8.4% for both measures. Santa Ines sheep have different growth rates for body measurements; whereas growth in posterior height stabilizes earlier, the thoracic circumference, along with body weight, remains growing for longer time. © 2012 Sociedade Brasileira de Zootecnia. Source

de Andrade Souza L.,Pos Graduacao em Zootecnia | Caires D.N.,Pos Graduacao em Zootecnia | Carneiro P.L.S.,State University of Southwest Bahia | Malhado C.H.M.,State University of Southwest Bahia | Filho R.M.,Federal University of Ceara
Revista Ciencia Agronomica

The objective of this study was to analyze nonlinear models to describe growth of Indubrazil cattle raised in Sergipe State. After defining the best adjusted model, it was evaluated the influence of environmental effects (sex, farm, month and year of birth) over mature weight (A) and maturation rate (k). Data from 1,201 animals weighed in nearly 90-day intervals from birth up to two years of age were used, based on records from the Brazilian Association of Zebu Breeders (ABCZ). The models utilized were Brody, Von Bertalanffy, Richards, Logistic and Gompertz. The Logistic model presented best adjustment followed by Gompertz and Von Bertalanffy models. The parameters A (weight at maturity) and k (maturation rate), obtained by the Logistic model were 427.87 and 0.0052, respectively. An accentuated decrease in the absolute growth rate was observed after weaning and nutritional strategies should be performed to avoid the low weight gain at this stage. Environmental factors affected significantly the parameters A and k. The correlation estimated between the parameter A and k was negative (-0.62), indicating that fast-growing young animals are less likely to reach higher weights when adults. Source

Calderano A.A.,Pos Graduacao em Zootecnia | Gomes P.C.,UFV Vicosa | Donzele J.L.,UFV Vicosa | Barreto S.L.D.T.,UFV Vicosa | And 4 more authors.
Revista Brasileira de Zootecnia

The objective of this study was to determine the ideal digestible tryptophan:digestible lysine ratio in diets for laying hens from 24 to 40 weeks of age. Two hundred and forty Hy-Line W-36 laying hens at 24 weeks of age were distributed in a completely randomized design, with five treatments, eight replicates and six birds per experimental unit. The digestible tryptophan levels in the experimental diets were 1.57; 1.68; 1.79; 1.90 and 2.01 g/kg, providing ratios of digestible tryptophan:digestible lysine of 0.215; 0.230; 0.245; 0.260 and 0.275. The increase in the levels of digestible tryptophan in the diet linearly improved the feed intake, digestible tryptophan intake, digestible lysine intake, egg production, egg mass, feed conversion per egg mass and utilization efficiency of digestible lysine for eggs mass. There were quadratic effects from the digestible tryptophan levels on egg weight. For the efficiency of utilization of digestible lysine for egg mass, there was better adjustment of the data to the LRP model. The level of digestible tryptophan in the diet from which the plateau occurred was 0.184%. This level corresponded to the intake of 142 mg/bird/day of digestible tryptophan and digestible tryptophan:digestible lysine ratio of 0.252. The ideal digestible tryptophan:digestible lysine ratio recommended in diets for laying hens from 24 to 40 weeks of age is 0.252 (25.2%). ©2012 Sociedade Brasileira de Zootecnia. Source

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