Protein supplementation to early lactation dairy cows grazing tropical grass: Performance and ruminal metabolism

Autor(es)

Jado Chagas, Lucas ^[1] ; Delveaux Araujo Batalha, Camila ^[2] ; de Arruda Camargo Danes, Marina ^[3] ; Mauricio Santos Neto, Jose ^[4] ; Lopes Macedo, Fernanda ^[5] ; da Silva Marques, Rodrigo ^[6] ; Augusto Portela Santos, Flavio ^[5]

Afiliação do(s) autor(es)

^[1] Dept Res & Dev, Roullier Anim Nutr, Minga Guazu - Paraguay

^[2] Ctr Avancado Pesquisa Bovinos Corte, Inst Zootecnia, Sertaozinho - Brazil

^[3] Univ Lavras, Dept Anim Sci, Lavras - Brazil

^[4] Michigan State Univ, Dept Anim Sci, E Lansing, MI 48824 - USA

^[5] Univ Sao Paulo, Dept Anim Sci, Sao Paulo - Brazil

^[6] Montana State Univ, Dept Anim & Range Sci, Bozeman, MT 59717 - USA

• Tipo de documento: Artigo Científico
• Fonte: ANIMAL SCIENCE JOURNAL; v. 92, n. 1 JAN 2021.
• Citações Web of Science: 0

Resumo

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 x 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%. (AU)

• Processo FAPESP: 12/09535-1 - Suplementação de bovinos em pastagem tropical
• Beneficiário: Flávio Augusto Portela Santos
• Modalidade de apoio: Auxílio à Pesquisa - Temático