Data/hora: 04/06/2024 00:14:30

Provedor de dados: | 65
País: | Brazil
Título: | Milk production and percentages of fat and protein in Holstein breed cows raised in Rio Grande do Sul, Brazil
Autores: | Feltes,Giovani Luis; Michelotti,Vanessa Tomazetti; Prestes,Alan Miranda; Bravo,André Padilha; Bondan,Carlos; Dornelles,Mariana de Almeida; Breda,Fernanda Cristina; Rorato,Paulo Roberto Nogara.
Data: | 2016-04-01
Ano: | 2016
Palavras-chave: | Calving season; Hyperbolic linear function; Age at calving; Identity model test.
Resumo: | ABSTRACT: The objective of this study was to identify a nonlinear regression model that better describes the milk production and the percentages of fat and protein curves, and to identify the season and age of calving that result in higher productions. For the analysis, 8,047 records of milk production and percentages of fat and protein obtained from 1,330 Holstein breed cows raised in Rio Grande do Sul, born from 1989 to 2011, were used. After determining the most appropriate nonlinear regression model, the identity of models and the equality of parameter tests for the different classes of season and age of calving were performed. Residual mean square, mean absolute deviation, mean squared prediction error and percentage of estimated curves per animal, indicated the Linear Hyperbolic Function (LHF) as the most appropriate to describe the milk production and the levels of fat and protein curves. Cows calving in the autumn and winter seasons yield higher quantities of milk and lower fat and protein content than those calved in the spring and summer seasons. Cows aged between 46 and 93 months at calving yield higher milk quantities, and those with calving age between 94 and 118 months produced more fat.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016000400700
Editor: | Universidade Federal de Santa Maria
Relação: | 10.1590/0103-8478cr20150465
Formato: | text/html
Fonte: | Ciência Rural  v.46 n.4 2016
Fonte: | info:eu-repo/semantics/openAccess