Genetic and non-genetic effects on productive and reproductive traits of cows in dual-purpose herds in southeastern Mexico
Genet. mol. res. (Online)
; 4(3): 482-490, 2005. tab
Artigo
em Inglês
| LILACS
| ID: lil-444964
Biblioteca responsável:
BR1.1
ABSTRACT
Data on productive and reproductive performance of cows in dual-purpose herds were analyzed to determine the effect of some environmental and genetic factors on saleable milk yield (SMY), lactation length (LL), daily saleable milk per lactation (DMYL), calving interval (CI), and daily saleable milk per calving interval (MYCI) in dual-purpose herds in Yucatan, Mexico. Repeatabilities (re) for these traits were also estimated. Data were obtained from monthly visits to 162 herds from 1996 to 2000. The fixed factors studied were region (central, eastern and southern), parity number (1 to 6), calving year (1996 to 2000) and calving season (dry, rainy and windy and rainy), genetic group (low- (< 0.50%), medium- (50%) and high- (> 50%) grade cows with European genes). About 2700 to 7700 cows were evaluated for each trait. All factors had significant effects (P < 0.05) on the traits except for region on CI and calving season on DMYL. The overall means for SMY, LL, DMYL, CI, and MYCI were 1322.3 +/- 80.5 kg, 224.8 +/- 1.3 days, 5.8 +/- 0.1 kg, 555.1 +/- 16.5 days, and 3.0 +/- 0.1 kg, respectively. The re values for SMY, LL, DMYL, CI, and MYCI traits were 0.19 +/- 0.03, 0.08 +/- 0.04, 0.16 +/- 0.04, 0.00 +/- 0.08, and 0.08 +/- 0.07, respectively. First parity cows had lower SMY, shorter LL, longer CI, and lower MYCI means than cows with more than one parity. Medium grade cows produced more SMY, DMYL and MYCI and had shorter CI than low- and high-grade cows. Therefore, under Yucatan conditions medium-grade cows should be exploited, and more attention should be given to first parity cows in order to improve the productivity in the herd. The relatively high re estimates for SMY and DMYL can be used to calculate most probable producing abilities, in order to identify which cows should be culled.
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Base de dados:
LILACS
Assunto principal:
Reprodução
/
Lactação
/
Bovinos
/
Característica Quantitativa Herdável
/
Meio Ambiente
Tipo de estudo:
Estudo prognóstico
Limite:
Animais
País/Região como assunto:
México
Idioma:
Inglês
Revista:
Genet. mol. res. (Online)
Assunto da revista:
Biologia Molecular
/
Genética
Ano de publicação:
2005
Tipo de documento:
Artigo
País de afiliação:
México
Instituição/País de afiliação:
Campus Tabasco del Colegio de Postgraduados/MX
/
Universidad Autónoma de Yucatán/MX