Data/hora: 11/06/2024 07:15:05

Provedor de dados: | 96
País: | Brazil
Título: | Development and reproductive performance of Hereford heifers of different frame sizes up to mating at 14-15 months of age
Autores: | Silva,Maurício Dallmann da; Lobato,José Fernando Piva; Vaz,Ricardo Zambarda; Eloy,Lidiane Raquel; Vaz,Márcia Bitencourt.
Data: | 2018-01-01
Ano: | 2018
Palavras-chave: | Age at conception; Average daily gain; Body condition score; Hip height; Ovarian activity; Pregnancy rate.
Resumo: | ABSTRACT Body development and reproductive performance of a hundred forty-two 14 to 15-month-old heifers, classified at weaning according to frame size as small, medium, and large, were evaluated. The parameters evaluated were: body weight, hip height, body condition score, weight gain, ovarian activity, and pregnancy rate. At weaning, body weight and hip height were significantly different among frame scores, (small – 133.0 kg, 92.2 cm; medium – 158.5 kg, 96.6 cm; and large – 185.2 kg; 100.2 cm). After weaning, heifers grazed together on natural pastures during the autumn and on ryegrass (Lolium multiflorum La.) during the winter and spring. Frame score differences remained until the beginning of the breeding season (BS), starting on average at 14 months of age. Weight gain between weaning and the beginning of BS was not different among frame scores (0.740 kg/day, on average). Body weights at the beginning of the BS were significantly different, of 255.7 kg (53.3% of the mature weight) for small heifers, 285.0 kg (59.4%) for medium heifers, and 307.6 kg (64.1%) for large heifers. Ovarian activity at the beginning of the BS was not different among the three groups. The average weight gain values during the BS of 0.492, 0.472, and 0.421 kg/day for small, medium, and large heifers, respectively, were significantly different. Pregnancy rates were not different among groups (small, 71.4%; medium, 76.4%; and large, 76.5%). Frame score did not influence the reproductive performance of heifers, but the small and medium heifers conceived 29 and 20 days earlier, respectively, than the large heifers.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982018000100400
Editor: | Sociedade Brasileira de Zootecnia
Relação: | 10.1590/rbz4720170031
Formato: | text/html
Fonte: | Revista Brasileira de Zootecnia  v.47 2018
Fonte: | info:eu-repo/semantics/openAccess