Effect of the breed, the month of semen collection and artificial insemination on boar seminal parameters and sows performance at farrowing

Abstract

The aim of this work was to evaluate seminal variables and the results of artificial insemination during part of the spring-summer period. Information of 100 ejaculates and 363 AI from six Large White and Landrace adult boars during October'98-January'99, from a pig farm located in southern Uruguay (34º LS) was analysed. The effect of breed, month, and their interactions on the total number of piglets born and piglets born alive were studied. Furthermore, the effects of temperature (maximum TM, minimum Tm) and relative humidity (maximum RHM, minimum RHm) on collection day on seminal variables were studied. It was found an effect on volume, sperm concentration and abnormal sperm. The volume was affected by the month (P=0.0149); the TM (P=0.0274) and RHm (P=0.0506) influenced negatively; the Tm (P=0.0066) and TM*HRM (P=0.0412) affected positively. Temperatures (TM: P=0.0006, Tm: P=0.00044), and the interaction TM*HRM (P=0.001) also affect negatively sperm concentration. Percentage of abnormal sperm was affected by the month of collection. Male breed affected the litter size, LD>LW (P=0.0021). Month also affected parturition rate (P<0.01). The results suggested that the quality of the ejaculates collected during October-January did not seem to limit litter size either parturition rate. It was confirmed the seasonal infertility of the pigs in Uruguay.