Impact of Prl and Fst Loci Polymorphism on Sexual Activity of Puławska Gilts* *

PRL (prolactin) and FST (follistatin) genes were investigated and analysed with regard to values of selected indices determining the reproductive activity of gilts in heat. The performed analyses comprised gilts of Puławska breed kept within the framework of the Genetic Resources Protection Programme of Farm Animals. Ninety-six gilts were phenotyped (one set for FST and one set for PRL). Each genotype (PRL, FST) group was represented by an equinumerous population of 32 gilts. The analysis took into consideration the second and third spontaneous oestrus during which the following parameters were assessed: age, body weight, duration of the tolerance reflex in the phase of true oestrus and intensity of reproductive responses during the oestrus period. The sexual behaviour was estimated with the assistance of: the manual method, mounting with a simultaneous pressure with knees of the lumbosacral area, and using a teaser boar in accordance with a 3-point score. The performed experiments revealed a significant impact of polymorphism in the FST locus on oestrous activity. On the other hand, the PRL gene was found to affect feeding behaviour, motor activity (including oestrous) and contributed to lack of motor activity treated as rest or sleep.