Calving season, genotype and sex of crossbred taurus and indicus calves on the birth and weaning weight and individual efficiency of primiparous Hereford

Ciência Rural

Mendonça, Gilson de¹  Osório, José Carlos da Silveira¹  Pimentel, Marcelo Alves¹  Cardellino, Ricardo Alberto¹ 

[1] Universidade Federal de Pelotas, Pelotas

关键词: beef cattle;    cow efficiency;    birth weight;    weaning weight;   

DOI  :  10.1590/S0103-84782003000600018

学科分类：农业科学（综合）

来源: Universidade Federal de Santa Maria * Centro de Ciencias Rurais

【 摘 要 】

The objective of the present study was to evaluate the effect of calving season, genotype and calf sex on the cows weaning individual efficiency ( percentual relationship between cow body weight and calf weaning weight), birth and weaning weight of calves. Forty-eight primiparous Hereford cows with approximate average age of 3 years and grazing only native pastures were used. Sixteen inseminated with one Red Angus bull (Bos taurus) and 32 with Nelore (Bos indicus). Effects studied were calf genotype (GENOT), Bos taurus x Bos taurus and Bos taurus x Bos indicus, calving season (EPOCN) concentrated in the Spring and subdivided into three periods: 1S (September), 2O (October) and 3N (November and December) and calf sex (SEXO). Milk production (PL) was included as co-variable. Ten measurements of milk production obtained by the indirect method, weighing the calf before and after suckling, and eleven measurements of cow and calf weights, were made at 21 day intervals. Effects with significant influence on PN were GENOT and SEXO (P<0.05). P205 was significantly affected by EPOCN, SEXO and PL (P<0.05). EI was significantly affected by EPOCN, SEXO and PL until 147 days (P<0.05). Calf genotype and sex affected their birth weight. Weaning weight and cow efficiency are affected by sex and and calving season, but not by calf genotype.

【 授权许可】

CC BY-NC