Resumen

VERDE, Omar. Inbreeding and Its Effect on Growth Characters in Five Registered Brahman Herds in Venezuela. Rev. Fac. Cienc. Vet. [online]. 2016, vol.57, n.2, pp.78-84. ISSN 0258-6576.

Some 27098 individual records from five registered Brahman herds in Venezuela, were analyzed with a general lineal model in order to evaluate inbreeding levels for the period 2001 to 2012 and its possible negative effects on weight at time of birth, 205 days and 548 days of age. Besides inbreeding value, year and month of birth, sex and mother age were included in the model. General average of inbreeding was 0.574%, with a range from 0.37 to 2.20 for individual herds. Inbred animals averaged  from 0.95 to 4.53%. Less than 2.5% of the animals in the herds showed values higher than 12.8%. It was not detected any important increment of inbreeding value with time. Weighted averages showed negative regressions of - 68.4,  - 283.3 and - 614.6 gr associated with an increment of 1% of inbreeding, which means loss of 39, 163 and 352 gr by animal at birth, 205 days and 548 days of age, respectively. It is concluded that permanent mating programs in the herds must be maintained in order to minimize inbreeding effects.

Palabras clave : inbreeding; growth; Brahman.

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