Nutrient digestibility, nitrogen excretion, and milk production of mid-lactation Jersey × Friesian cows fed diets containing different proportions of rumen-undegradable protein



Título del documento: Nutrient digestibility, nitrogen excretion, and milk production of mid-lactation Jersey × Friesian cows fed diets containing different proportions of rumen-undegradable protein
Revista: Anais da Academia Brasileira de Ciencias
Base de datos: PERIÓDICA
Número de sistema: 000436145
ISSN: 0001-3765
Autores: 1
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Instituciones: 1University of Sargodha, Department of Animal Sciences, Sargodha, Punjab. Pakistán
2Northwest A&F University, College of Animal Science and Technology, Yangling, Shaanxi. China
3Zagazig University, Department of Animal Production, Zagazig, Sharqiya. Egipto
4Zagazig University, Department of Theriogenology, Zagazig, Sharqiya. Egipto
5King Saud University, Department of Animal Production, Riyadh. Arabia Saudita
Año:
Volumen: 92
País: Brasil
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Aplicado, descriptivo
Resumen en inglés The present study was planned to test the hypothesis that feeding lactating dairy cattle with varying levels of rumen-undegradable protein (RUP) can enhance protein utilization, milk production, milk protein, and nitrogen (N) excretion. Forty mid-lactating crossbred (Jersey × Friesian) cattle were randomly divided into four groups. Four treatment diets were formulated to contain 30%, 40%, 50%, and 60% RUP of crude protein. Dry matter (DM) and crude protein intakes were significantly reduced with increasing dietary RUP levels. Crude protein digestibility increased linearly with incremental increases in dietary RUP levels. Cattle fed 60% RUP showed a linear decrease in N intake compared to that in the other groups. A linear decrease in urinary N and linear increases in net N, milk N, and N-use efficiency were observed with increasing dietary RUP levels. Actual milk, energy-corrected milk, and 4% fat-corrected milk yields (kg/day) increased linearly with an increasing degradability of protein. However, milk protein, solids not fat and total solids, as well as the yields of protein, fat, and lactose, showed significant increases with increased RUP supplementation. Collectively, the results indicate that formulating dairy cow diets to contain 60% RUP results in better lactating performance and N-use efficiency and lower N excretion
Disciplinas: Medicina veterinaria y zootecnia
Palabras clave: Bovinos,
Nutrición animal,
Vacas,
Jersey x Friesian,
Experimentos de alimentación,
Proteína no degradable,
Excreción de nitrógeno,
Digestibilidad,
Producción de leche
Keyword: Bovines,
Animal nutrition,
Cows,
Jersey x Friesian,
Feeding experiments,
Undegradable protein,
Nitrogen excretion,
Digestibility,
Milk production
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