Consumo e digestibilidade total dos nutrientes e produção e composição do leite de vacas alimentadas com teores crescentes de proteína bruta na dieta contendo cana-de-açúcar e concentados
Carregando...
Data
2007-12-01
Autores
Cordeiro, Carla Fabrícia de Araujo
Pereira, Mara Lúcia Albuquerque
Mendonça, Sandro de Souza [UNESP]
Almeida, Paulo José Presidio
Aguiar, Luzyanne Varjão
Figueiredo, Mauro Pereira de
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Zootecnia
Resumo
Objetivou-se avaliar o efeito de teores crescentes de PB na MS total da dieta (11,5; 13,0; 14,5 e 16,0%) sobre os consumos e a digestibilidade total dos nutrientes e a produção e composição do leite de vacas leiteiras no terço inicial da lactação. O experimento foi constituído de quatro períodos experimentais de 15 dias, sete para adaptação dos animais à dieta e oito para coleta de dados. Foram utilizadas oito vacas, manejadas em cochos individuais, distribuídas em dois quadrados latinos balanceados 4 × 4. Utilizou-se concentrado à base de farelo de algodão e fubá de milho (40%) e, como volumoso, cana-de-açúcar corrigida com 1% de uréia + sulfato de amônio (9:1), na proporção de 60% (% MS). Os consumos médios diários de nutrientes, exceto EE e CNF, diferiram à medida que os teores de PB da dieta aumentaram. Os teores de PB na dieta não afetaram os coeficientes de digestibilidade aparente total dos nutrientes. A produção de leite corrigida ou não para 3,5% de gordura e seus componentes (gordura, PB e lactose), expressa em g/dia, e o nitrogênio uréico no leite (NUL) tiveram efeito linear crescente, enquanto a eficiência de utilização de N sofreu efeito linear negativo dos teores de PB da dieta. A dieta com 16% PB resultou em valores numericamente maiores de consumo e produção do leite e de seus componentes se comparada às dietas com menores teores de PB.
The objective of this research was to evaluate the effect of increasing levels of CP in the total DM of diet (11.5, 13.0, 14.5 and 16.0%) on the intakes and the total digestibility of nutrients and the milk production and composition of dairy cows in initial third of lactation. The research was constituted by four experimental periods of 15 days each, seven for adaptation of the animals to the diet and eight for data collection. Eight cows, individually fed, were distributed to two balanced 4 × 4 Latin squares. A cottonseed meal, ground corn-based concentrate (40%) was used and, as forage, sugar cane corrected with 1% of urea + ammonium sulfate (9:1), in the proportion of 60% (%DM). The daily average intakes of nutrients, except for EE and NFC, differed as the levels of CP increased in the diet. The protein levels in the diet did not affected the coefficients of total apparent digestibility of the nutrients. Production of fat corrected milk, 3.5% or not and its components (fat, CP and lactose), expressed in g/day, and milk urea nitrogen showed increased linear effect, while the N efficiency showed negative linear effect of the CP levels in the diet. The diet with 16% CP provided values numerically greater for intake and milk production and its components as compared to diets with lower levels of CP.
The objective of this research was to evaluate the effect of increasing levels of CP in the total DM of diet (11.5, 13.0, 14.5 and 16.0%) on the intakes and the total digestibility of nutrients and the milk production and composition of dairy cows in initial third of lactation. The research was constituted by four experimental periods of 15 days each, seven for adaptation of the animals to the diet and eight for data collection. Eight cows, individually fed, were distributed to two balanced 4 × 4 Latin squares. A cottonseed meal, ground corn-based concentrate (40%) was used and, as forage, sugar cane corrected with 1% of urea + ammonium sulfate (9:1), in the proportion of 60% (%DM). The daily average intakes of nutrients, except for EE and NFC, differed as the levels of CP increased in the diet. The protein levels in the diet did not affected the coefficients of total apparent digestibility of the nutrients. Production of fat corrected milk, 3.5% or not and its components (fat, CP and lactose), expressed in g/day, and milk urea nitrogen showed increased linear effect, while the N efficiency showed negative linear effect of the CP levels in the diet. The diet with 16% CP provided values numerically greater for intake and milk production and its components as compared to diets with lower levels of CP.
Descrição
Palavras-chave
farelo de algodão, proteína não-degradável no rúmen, terço inicial da lactação, cottonseed meal, early lactation, rumen undegradable protein
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 36, n. 6, p. 2118-2126, 2007.