BREED AND ENVIRONMENTAL EFFECTS ON BIRTH WEIGHT, WEANING WEIGHT AND CALVING INTERVAL OF ZEBU CATTLE IN SOUTHEASTERN MEXICO
Records of beef cows from a ranch in southern Mexico gave 1967 birth weights (BW), 1587 weaning weights adjusted to 210 days of age ( A WW) and 2001 calving intervals (CI) for the comparison of the breed groups: Brahman (B R ), Guzerat (GU), Nellore (NE) and crosses born to zebu dams by Brown Swiss...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | México |
| Institución: | Universidad Autónoma de Yucatán |
| Repositorio: | Redalyc-UADY |
| OAI Identifier: | oai:redalyc.org:93952506011 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=93952506011 |
| Access Level: | acceso abierto |
| Palabra clave: | Agrociencias tropics purebred cows Crossbred cattle preweaning traits |
| Sumario: | Records of beef cows from a ranch in southern Mexico gave 1967 birth weights (BW), 1587 weaning weights adjusted to 210 days of age ( A WW) and 2001 calving intervals (CI) for the comparison of the breed groups: Brahman (B R ), Guzerat (GU), Nellore (NE) and crosses born to zebu dams by Brown Swiss sires. Animals were fed mainly pasture . Data were analysed using general linear procedures. Th e statistical model that described the data for BW and A WW included the fixed effects of breed group (B R , GU, NE, BS x B R , BS x GU and BS x NE); year of birth or calving (20 0 5 to 2014), season of parity of the cow (dry, rainy, windy), sex of the calf (fema le or male), parity (1 to =>8) and the simple interaction of year x season of birth or calving. The model for CI wa s similar to the previous one, except that only the Zebu purebreds were included. The overall means and standard deviations for BW, AWW and C I were 33.5 + 0.75 kg, 178.9 + 19.7 kg and 456.4 + 79.2 days. All effects included in the model had significant effect on BW and A WW, but season and sex on CI. The smallest least squares means for BW corresponded to the cross of B R x NE and the largest to the cross of BS x BR (33.3 and 33.7 kg, respectively) ; whereas the lowest and largest least squares means for A WW corresponded to the NE ( 173.8 kg) and BS x BR (1 91.8 kg ). NE cows ha d shorter CI than BR and GU cows (413.9, 446.2 and 481.3, respectively ) . Male calves weighed m ore at birth and w e aning than females . Year x season interaction indicate that season effects on performance of calves or cows were not similar throughout the year s studied. |
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