Suplementação de bezerras de corte lactentes e em recria e parâmetros nutricionais de vacas de corte em pastejo

• Autor(a) principal: Valente, ériton Egidio Lisboa
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5609
• topic: Bovinos; Creep feeding; Desempenho; Bovine; Creep feeding; Performance; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL

Two experiments were conducted. The first work aimed to evaluate the performance of female calves in creep feeding receiving different supplementation strategies, milk production, intake and digestibility of pasture by Nellore or crossbred cow (Nellore x Holstein), on pasture of Brachiaria decumbens Stapf during the dry-rainy transition season. Forty four female beef suckling calves, with age between 90 and 150 days and average initial body weight of 117.7 + 4.3kg, and their dam (24 Nellore and 20 crossbred) with average initial body weight of 417.5 + 8.3 kg, were used. The treatments were: TMM (control) mineral mixture, ad libitum; Strategy 1 supplement provided from 112 days prior to weaning, 0.375 kg/animal/day. Strategy 2 - supplement provided from 112 days prior to weaning, in increasing amount, 0.15, 0.30, 0.45 and 0.60 kg/animal/day for the four sub-periods, in this order. Strategy 3 - supplement provided from 56 days prior to weaning, 0.750 kg/animal/day. The animals of strategy 1 had higher average daily gain (0.672 kg/day) than control animals (0.582 kg/day) (P<0.10) and better efficiency of supplement use. The strategy of supplementation of female calves did not influence weight gain, body condition score and the milk production of cows (P>0.10). The crossbred cows produced more milk (6.21 kg) than Nellore cows (5.37 kg/day) (P<0.10). The intake of dry matter (DM) were higher (P<0.10) in crossbred cows. However, there were not differences in the nutrients digestibility between the genetic groups. It can be concluded that supplementation strategies in which there are equitable distribution along the period prior to weaning, provides higher weight gain in female calves. Crossbred cows produce more milk production and have higher intake of DM than Nellore cows. There are not differences in the nutrients digestibility between cow Nellore and crossbred cow (Nellore x Holstein). The second work aimed to evaluate the performance, microbial protein synthesis, intake and digestibility of nutrients of beef heifers receiving increasing levels of multiple supplements or nitrogen salt, in self-fed, on Brachiaria decumbens Stapf. pasture, during the dry season. Thirty five beef heifers, with age and average body weight of 8 months and 203.4 + 4.5 kg, respectively, were used. The treatments were: MM (control) mineral mixture, ad libitum; SN (nitrogen salt) supplement with 75 % of CP, based on urea + mineral mixture, in proportion of 1:1 (50%), and corn (50%); Q1, Q2, Q3 multiple supplements with 40 % of CP, using different proportions of intake controller mixture (urea + mineral mixture, in proportion of 1:1), corn and soybean meal. The consumptions observed were: 115, 173, 572 e 1214 g/animal/day for the treatments SN, Q1, Q2 and Q3, respectively. The levels of urea + salt resulted in quadratic effect on consumption of supplement (P<0.10). The supplemented animals had higher (P<0.10) average daily gain (ADG). The supply of multiple supplement resulted on positive linear effect on ADG (P<0.10). However, on average, there was not significant effect (P>0.10) on ADG of animals that received multiple supplements or nitrogen salt. The supplementation increased (P<0.10) the intake and digestibility of nutrients, with exception of digestibility of the neutral detergent fiber (NDF), although the intake of digested FDN had increased (P<0.10). The supplementation increased (P<0.10) the production of microbial nitrogen as well as nitrogen losses in urine, although the quantity of assimilated nitrogen by bacteria, on proportion to intake, was higher on the higher levels of multiple supplements. It can be conclude that urea + salt control the intake of supplement on nonlinear way. The levels of multiple supplement result on positive linear effect on ADG and, on average, have similar gain to nitrogen salt. The supplementation increases the intake, digestibility, microbial nitrogen production and the ADG.