Resumo

GONCALVES, R.W. et al. Effect of inbreeding on morfhometric traits in Mangalarga Marchador horses. Arq. Bras. Med. Vet. Zootec. [online]. 2012, vol.64, n.2, pp. 419-426. ISSN 0102-0935.  http://dx.doi.org/10.1590/S0102-09352012000200023.

The coefficient of inbreeding was estimate and its effect on linear traits of the Mangalarga Marchador horses reared in a ranch in the North of Minas Gerais was evaluated. The characteristics studied were morphometric traits such as wither and hip height, length of head, neck, back-loin, hip and body, as well as chest and hip width. The archive had 2186 data on the genealogy of animals from the herd register of the Catuni Farm. The coefficient of inbreeding (F) was calculated and its effect was evaluated by means of simple linear regression on the linear traits. Of all animals, 27.6% showed inbreeding, with an F average of 1.4% in the population. Considering only the inbred animals, the average consanguinity reached 5.3% minimum of 0.1 and maximum of 28.1%. Negative effects of inbreeding on the morphometric traits were not seen, except for hip width, where for each 10% increase in F there was increase of 0.576cm. Possibly due to the low value found, inbreeding did not influence the other evaluated characteristics.

Palavras-chave : horse; consanguinity; inbreeding depression; linear measures.