<b>Protected fat and variable level of protein in diets of crossbreed cows in early lactation

Abstract

ABSTRACT. Current study evaluated the inclusion of protected fat and different levels of crude protein (CP) in the diet of crossbreed cows in early lactation. Twelve cows were distributed in a 4 x 4 factorial design, with four treatments (12 or 16% CP, with or without MEGALAC-E ® ). Statistical analyzes with ANOVA and Pearson's linear correlation procedures were performed. Protected fat did not affect intake of dry matter (DM) and organic matter (OM) (p > 0.05). Increased CP raised consumption of CP and EE and decreased the non-fiber carbohydrates (NFC; p <0.05). Protected fat increased (p <0.05) the digestibility of DM, OM, CP and ashes in the lower protein content. CP increase raised the level of blood and urinary urea (p < 0.05). There was no difference (p > 0.05) on milk yield and composition due to protected fat or CP rates. Since the inclusion of protected fat and higher content of CP (16%) in the diet did not benefit the production and composition of milk in crossbreed cows, diets with 12% CP without the inclusion of protected fat are recommended.Keywords: concentrate, dietary protein, digestibility, intake, lipid supplementation, milk yield.Gordura protegida e nível variável de proteína em dietas para vacas mestiças no terço inicial da lactação RESUMO. O objetivo desse estudo foi avaliar a inclusão de gordura protegida e de diferentes níveis de PB, na dieta para vacas mestiças, no início da lactação. Foram utilizadas 12 vacas, distribuídas em quadrados latinos 4 x 4 e quatro tratamentos (12 ou 16% de PB, com ou sem MEGALAC-E ® ). Análises estatísticas foram realizadas utilizando Anova e correlações lineares de Pearson. A gordura protegida não influenciou o consumo de MS e MO (p > 0,05). O aumento de PB elevou o consumo de PB e EE e diminuiu o de carboidratos não fibrosos (CNF; P<0,05). A gordura protegida aumentou (p < 0,05) a digestibilidade da MS, MO, PB e cinzas no menor teor de proteína. O aumento de PB elevou os níveis de ureia sanguínea e urinária (p < 0,05). Não houve diferença (p > 0,05) na produção e composição do leite em função da gordura protegida ou do teor de PB. A inclusão de gordura protegida e o maior teor de PB (16%) na dieta não resultaram em benefícios na produção e composição do leite de vacas mestiças, portanto recomenda-se utilizar dietas contendo 12% de PB, sem a inclusão de gordura protegida.Palavras-chave: concentrado, proteína dietética, digestibilidade, consumo, suplementação lipídica, produção de leite.

Effect of Supplementation Dietary Dry Fat on Productive and Reproductive Performance on Egyptian Lactating Buffaloes

“…Sharma et al (2016) indicated that protein; lactose and solid not fat content did not varied between the groups. Souza Júnior et al (2016) suggested no difference (P>0.05) on milk composition due to protected fat or CP rates. In current study, energy of milk was significantly (P≤ 0.05) higher in DF groups than those of corroborating results by Zeedan et al (2014) and S Sa af fa aa a (2015).…”

“…Sharma et al (2016) indicated that buffaloes consumed DM during post-partum between the groups (CG and SG) were non-significant. Souza Júnior et al (2016) indicated that treatments (MEGALAC) had no effect on consumption of dry matter (DM). On the other hand; Abu El-Hamd et al (2012) suggested that the average DM (kg/d/h) during postpartum periods were higher in G 2 than G 1 of cows.…”