Data/hora: 30/05/2024 06:26:55

Biblioteca(s): 	Embrapa Gado de Leite.	
Data corrente: 	03/12/2021	
Data da última atualização: 	03/12/2021	
Autoria: 	LEÃO, J. M.; COELHO, S. G.; LAGE, C. F. de A.; AZEVEDO, R. A. de; LIMA, J. A. M.; CARNEIRO, J. C.; FERREIRA, A. L.; MACHADO, F. S.; PEREIRA, L. G. R.; TOMICH, T. R.; DINIZ NETO, H. do C.; CAMPOS, M. M.	
Afiliação: 	JULIANA MERGH LEÃO, Universidade Federal de Minas Gerais; SANDRA GESTEIRA COELHO, Universidade Federal de Minas Gerais; CAMILA FLÁVIA DE ASSIS LAGE, Universidade Federal de Minas Gerais; RAFAEL ALVES DE AZEVEDO, Universidade Federal de Minas Gerais; JULIANA APARECIDA MELLO LIMA, Universidade Federal de Minas Gerais; JULIANA CAMPOS CARNEIRO, Universidade Federal de Minas Gerais; ALEXANDRE LIMA FERREIRA, Universidade Federal de Minas Gerais; FERNANDA SAMARINI MACHADO, CNPGL; LUIZ GUSTAVO RIBEIRO PEREIRA, CNPGL; THIERRY RIBEIRO TOMICH, CNPGL; HILTON DO CARMO DINIZ NETO, Universidade Federal de Minas Gerais; MARIANA MAGALHAES CAMPOS, CNPGL.	
Título: 	How divergence for feed efficiency traits affects body measurements and metabolites in blood and ruminal parameters on pre-weaning dairy heifers.	
Ano de publicação: 	2021	
Fonte/Imprenta: 	Animals, v. 11, 3436, 2021.	
DOI: 	https://doi.org/10.3390/ani11123436	
Idioma: 	Inglês	
Conteúdo: 	The objectives of this study were: (1) to evaluate feed efficiency indexes and their relationships with body measurements and blood and ruminal metabolites in the pre-weaning period; (2) to determine if such measurements can be used as feed-efficiency markers during the pre-weaning period. Holstein?Gyr heifer calves (n = 36), enrolled between 4 and 12 weeks of age, were classified into two residual feed intake (RFI) and residual body weight gain (RG) groups: high efficiency (HE; RFI, n = 10; and RG, n = 9), and low efficiency (LE; RFI, n = 10; and RG, n = 8). Calves were fed whole milk (6 L/day) and solid feed ad libitum. Body developments were measured weekly and feed intake (milk and solid feed) daily during the whole period. Blood samples were collected at 12 weeks of age and analyzed for glucose, insulin and ?-hydroxybutyrate (BHB). Samples of ruminal content were collected on the same day and analyzed for pH, NH3 -N, and volatile fatty acids (VFA). Among the growth characteristics, only the initial hip width differed between the RFI groups, and withers height differed between the RG groups. Concentration of BHB was greater and glucose: insulin ratios tended to be greater in LE-RG animals. Butyric acid proportions were similar among RFI groups, but tended to be greater for HE-RG than for LE-RG. Overall, correlation coefficients between RFI or RG and blood, rumen, or morphometric markers were low. Thus, it is unlikely that measurements of metabolic indicators, per se, will be useful in the early identification of more efficient animals. Understanding the underlying physiological basis for improved feed efficiency in dairy heifers requires further investigation	
Palavras-Chave: 	Alta eficiência; Baixa eficiencia; Crescimento residual; Eficiência alimentar.	
Thesagro: 	Gado Leiteiro; Novilho Leiteiro.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Gado de Leite (CNPGL)	
Exemplares: 	CNPGL - (25501-1) - UPC - AP - DD -  -  -  - DIS