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Estimates of breed average direct, maternal and heterosis effects for some productive traits of swine in the mexican tropics

P. Chimal; J.C. Segura

Facultad Medicina Veterinaria Zootecnia, Universidad Autonom de Yucatan, Apartado Postal 4-116, Merida Yucatan, 97100, Mexico. Send correspondence to J.C.S.

ABSTRACT

Records from 2985 purebred and crossbred litters farrowed in a commercial farm in the southeast of Mexico were analyzed. A multiple regression procedure was used to obtain estimates of breed average direct, breed maternal, and direct and maternal heterosis effects for the Duroc (D), Hampshire (H), American Landrace (L) and Yorkshire (Y) breeds and their crosses. Average direct and maternal effects were expressed as deviations from the Y breed. Average direct effects for litter size and weight at birth and litter size at weaning did not differ significantly among breeds although, in general, the Y breed was the best. Landrace average effect for litter weight at weaning was large and significant (P < 0.05). Breed maternal effects for all preweaning traits were in general small for the D and H breeds, but large and significant for the L breed (P < 0.05). Direct and maternal heterosis effects were in general significant (P < 0.05) for litter size and weight at weaning.

Keywords: maternal effects; heterosis effects; swine; mexican tropics.

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