Influence of boar contact on gilt age at puberty

Abstract

In this review of the literature we have investigated the influence of boar contact on the puberty attainment in the gilt. Nature of the sensory cues involved, endocrine reaction of the female and influence of endogenous and environmental factors on the efficiency of the boar to advance puberty were successively analysed. The boar stimulus is very complex and seems to involve olfactory, auditory, visual and tactile cues. The gilt reacts to the introduction of the boar with an increase in cortisol secretion which could be necessary but not sufficient, in itself, to stimulate sexual development. Decrease in the age at puberty, due to boar influence, has been observed with various genotypes of females. The effect is highest with a mature male and when there are full physical contacts. Exposure of short duration (10 to 30 minutes/day) give similar results as permanent contacts. Exposure of females to the male during the growing phase does not seem detrimental to the efficiency of subsequent boar introduction.