Factors which influence parameters of goat lactation curves in the Federal District

Revista Brasileira de Zootecnia

Louvandini, Helder²  McManus, Concepta²  Mariante, Arthur da Silva¹  Soares Filho, Guilherme³ 

[1] Embrapa, Brasília;UnB, Brasília;Faculdade da Terra de Brasília

关键词: enviromental factors;    goodness of fit;    parameters    Introdução A curva de lactação é um importante estudo que possibilita a identificação de possíveis falhas de manejo de um determinado rebanho;    como alimentação deficiente;    instalações inadequadas;    patologias não aparentes;    entre outras (Graminha et al;   

DOI  :  10.1590/S1516-35982003000700010

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 摘 要 】

The objetive of this work was to evaluate the effect of environmental factors on the shape of lactation curves (Quadratic, Gama, Linear Hiperbolic and Jenkins & Ferrel) of Saanen, Alpine and Toggenburg as well as mixed breed goats. Data from 299 lactations of 215 goats raised on two farms in the Federal District from 1995 to 1997 was used. The parameters of the lactation curves (yield at start of lactation- a, rate of increase of milk production - b e rate of decline of milk production after peak rate - c) were estimated using the Table Curve program from Jandel Scientific. The parameters were then analysed using SAS (Statistical Analysis System) (CORR and GLM procedures). The statistical model included fixed effects (farm, breed, month and year of kidding, type of kidding, kid sex) and covariates (weight at insemination). Parameters a and c were influenced by breed, month of kidding as well as type of kidding. The Quadratic and Linear Hyperbolic curves had the highest R2. The correlations between curve parameters and production indices were, in general, high and positive. This study shows that any in the functions studied may be used to represent the individual lactation curve of herd, however, the curve that best expressed the shape of the lactation curve for goats was the Quadratic function while the Linear Hyperbolic and Jenkins and Ferrel had higher correlation between total production and curve parameters.

【 授权许可】

CC BY-NC