Genetic relationship between cyclic ovarian activity in heifers and cows and beef traits in males |
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Authors: | Marie-Madeleine Mialon Gilles Renand Daniel Krauss Fran?ois Ménissier |
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Affiliation: | 1.Station de génétique quantitative et appliquée, Institut national de la recherche agronomique, 78352 Jouy-en-Josas Cedex, France;2.Domaine expérimental de Galle, Institut national de la recherche agronomique, 18520 Avord, France |
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Abstract: | Records were collected in an experimental herd over an 11-year period from purebred Charolais heifers (n = 351), cows (n = 615) and young entire bulls (n = 383). The objective of the study was to estimate the genetic relationship between the components of female ovarian activity (age at puberty and postpartum anoestrus length), their growth rate and body condition score and beef traits measured on related bulls. Two methods were used to estimate age at puberty and postpartum anoestrus length: the detection of oestrous behaviour and a test of cyclicity based on plasmatic progesterone assay. This study shows the existence of significant heritability estimates for the different cyclicity traits (h2 between 0.11 and 0.38). Most of the genetic correlation coefficients between ovarian activity and growth rate of females and males are negative and favourable (rg between -0.43 and 0.06). Cyclicity is also favourably related with body condition score in young or adult females (rg between -0.65 and -0.22). The genetic relationship between female ovarian activity and proportion of adipose tissue in the male carcass is, however, close to zero. These results show that an antagonism between male beef traits measured in this study and female ovarian activity is unlikely to be a cause for concern in the short term. |
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Keywords: | genetic relationships ovarian activity beef-traits cattle |
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