FERTILITY OF SOWS AFTER INTRACERVICAL OR INTRAUTERINE INSEMINATION WITH DIFFERENT SPERMATOZOA NUMBER IN REDUCED VOLUME DOSES

Modern intensive pig production demands an increasing number of insemination doses per ejaculate of genetically superior boars. In order to achieve such a result the possibility of producing insemination doses in both reduced volume and spermatozoa count without decreasing the fertility of sows is studied. In this trial we studied the effect of insemination with reduced volumes of semen (50 mL) and varied spermatozoa count (4, 2 or 1x109). Insemination was performed by the classical (intracervical) or by the new (intrauterine) techniques and the basic fertility parameters (farrowing % and litter size) were measured. The farrowing value decreased with decreasing spermatozoa numbers after intracervical and intrauterine insemination. However, the farrowing value, regardless of spermatozoa numbers, was significantly higher after intrauterine insemination (83.3%, 76.7%, 66.7%) compared to the classical intracervical insemination (73.3%, 66.7% and 50%). Litters size did not vary significantly depending on the applied insemination procedure or spermatozoa number. These results indicate that application of the new intrauterine insemination procedure enables the use of doses with a smaller volume and spermatozoa number, at the same time obtaining a satisfactory farrowing and litter size. This opens the possibility of obtaining a significantly higher number of doses per ejaculate when compared to the classical intracervical insemination procedure. In such a way can be increased significantly the degree of reproductive exploitation of genetically superior boars.