Data/hora: 01/06/2024 07:56:24

Biblioteca(s): | Embrapa Gado de Leite.
Tipo da produção científica: | Artigo em Periódico Indexado
Circulação/Nível: | A - 2
Data corrente: | 21/08/2023
Data da última atualização: | 21/08/2023
Autoria: | MAIA, G. G.; SIQUEIRA, L. G. B.; VASCONCELOS, C. O. de P.; TOMICH, T. R.; CAMARGO, L. S. de A.; RODRIGUES, J. P. P.; MENEZES, R. A. de; GONÇALVES, L. C.; TEIXEIRA, B. F.; GRANDO, R. de O.; NOGUEIRA, L. A. G.; PEREIRA, L. G. R.
Afiliação: | GILSON GONÇALVES MAIA, Universidade Federal Fluminense; LUIZ GUSTAVO BRUNO SIQUEIRA, CNPGL; CARLOS OTÁVIO DE PAULA VASCONCELOS, Universidade Federal Fluminense; THIERRY RIBEIRO TOMICH, CNPGL; LUIZ SERGIO DE ALMEIDA CAMARGO, CNPGL; JOÃO PAULO PACHECO RODRIGUES, Universidade Federal do Sul e Sudeste do Pará; RAFAEL ARAÚJO DE MENEZES, Universidade Federal de Minas Gerais; LÚCIO CARLOS GONÇALVES, Universidade Federal de Minas Gerais; BRIDA FAGGION TEIXEIRA, Instituto de Desenvolvimento do Alto Uruguai; RODRIGO DE OLIVEIRA GRANDO, Instituto de Desenvolvimento do Alto Uruguai; LUIZ ALTAMIRO GARCIA NOGUEIRA, Universidade Federal Fluminense; LUIZ GUSTAVO RIBEIRO PEREIRA, CNPGL.
Título: | Effects of heat stress on rumination activity in Holstein-Gyr dry cows.
Ano de publicação: | 2020
Fonte/Imprenta: | Livestock Science, v. 239, 104092, 2020.
DOI: | https://doi.org/10.1016/j.livsci.2020.104092
Idioma: | Inglês
Conteúdo: | The objective of this study was to evaluate the effects of heat stress (HS) on: i) time and daily pattern of rumination and ii) in situ degradability in Holstein-Gyr crossbred dry cows. Nine cows, weighing 556.2 ± 97.1 kg were housed in a climate chamber (average THI=83.1) or a freestall barn (average THI=66.5) randomly assigned to treatments in a crossover design. Cows were fed corn silage ad libitum and 1 kg of concentrate as a maintenance diet. To measure rumination, we used a sensor attached to a collar. The in situ ruminal degradability was evaluated by incubation of concentrate, silage, and diet samples into the rumen of a fistulated cow for 6, 24, 48 and 96 h. The RT was affected by HS (P<0.001) and time of the day (P<0.001). The rumination pattern for control and HS cows had a first peak at approximately 04:00h and the magnitude of this peak in HS was 22.9% less than controls. The second RT peak occurred in the evening (~20:00h), when RT in HS was 27.8% less compared with controls. We observed a reduction in dry matter digestibility (DMD) of concentrate (85.1% vs 77.8%, control and HS, respectively; P<0,05) and also in the slow-degradable fraction of concentrate (93.9% vs 85.1%, respectively; P<0,05). Finally, DMD of the diet reduced from 73% to 70% for animals exposed to HS compared to controls. In conclusion, HS negatively affected e rumination time and in situ ruminal degradability in dry dairy cows.
Palavras-Chave: | Câmara climatizada; Cinética ruminal; THI.
Thesagro: | Bovino; Digestibilidade; Gado Gir; Gado Holandês; Vaca Leiteira.
Categoria do assunto: | L Ciência Animal e Produtos de Origem Animal
Registro original: | Embrapa Gado de Leite (CNPGL)
Exemplares: | CNPGL - (26076-1) - UPC - AP - DD -  -  -  - DIS