Protein supplementation to early lactation dairy cows grazing tropical grass: Performance and ruminal metabolism.
Anim Sci J
; 92(1): e13564, 2021.
Article
em En
| MEDLINE
| ID: mdl-34047427
This experiment was designed to evaluate the effects of different concentrate crude protein (CP) concentration on performance, metabolism and efficiency of N utilization (ENU) on early-lactation dairy cows grazing intensively managed tropical grass. Thirty cows were used in a ten replicated 3 × 3 Latin square design. The treatments consisted of three levels of concentrate CP: 7.9%, 15.4%, and 20.5% offered at a rate of 1 kg (as-fed basis)/3 kg of milk. The cows fed low and medium CP had negative balance of rumen degradable protein and metabolizable protein. Increasing CP tended to linearly increase DMI, 3.5% FCM and milk casein, and linearly increased the yields of milk fat and protein. Increasing CP linearly increased the intake of N, the concentration of rumen NH3 -N, and the losses of N in milk, urine, and feces. Increasing dietary CP linearly increased the molar proportion of butyrate but had no effect on the other rumen VFAs and no effect on microbial yield. In conclusion, feeding a concentrate with 20.5% of CP to early-lactation dairy cows grazing tropical grasses, leading to a 17.8% CP diet, tended to increase DMI, increased the yield of 3.5% FCM and the milk N excretion, and decreased ENU by 32%.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Rúmen
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Clima Tropical
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Lactação
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Bovinos
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Proteínas Alimentares
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Suplementos Nutricionais
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Leite
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Dieta
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Herbivoria
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Poaceae
Limite:
Animals
Idioma:
En
Revista:
Anim Sci J
Assunto da revista:
MEDICINA VETERINARIA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Paraguai
País de publicação:
Austrália