Effect of a paramunity inducer on reproductive performance of gilts.

Optimal reproductive performance of gilts is an economically important characteristic which is influenced amongst others by the general health condition of the animal. In the present pilot study, we examined whether reproductive performance of gilts that were transported from a breeding to a commercial farm can be improved by paramunization, e.g. by enhancing the non-specific immunological response of the animal. Three groups of gilts were submitted to various treatments as follows. The first group received no treatment and served as the control group. The gilts of the second group were injected twice with a paramunity inducer derived from a sheep parapoxvirus (Baypamun liquid, Bayer, Germany), once 2 days before the transport and a second time 2 h before departure. The gilts of the third group were treated as those of the second group, but received an additional injection 2 days after their arrival at the commercial farm. Gilts were compared up to their first farrowing with regard to the appearance of oestrus, the number of the gilts which became pregnant, and the cost of supportive medication. Their litter size at farrowing, the number of piglets born alive and the litter weight have also been recorded. The results show that the number of gilts that showed oestrus and became pregnant was increased after Baypamun liquid treatment, particularly in the third group. The cost of supportive medication per gilt was much lower in treated groups compared to untreated animals. The treatment did not have a significant effect on the total number of piglets born, but some beneficial effect was seen in the number of piglets born alive and the average piglet weight at birth of gilts treated three times with Baypamun liquid. It was concluded that paramunization of gilts at the time of transport may improve their reproductive performance.