Abstract: The aim of this study is to access libido (sex drive) and examine the quality of ejaculates collected from Yorkshire (Large White) and Landrace boars, taking into account the potential effects of season and breed over a test period of one year. Two sexually mature boars (one from each breed, Yorkshire and Landrace) were trained to mount a dummy and ejaculate. Libido scores were assigned to boars during each semen collection. Scores ranged from zero to four, with zero indicating minimum and four indicating maximum libido. Upon collection, standard laboratory tests were utilized to evaluate volume of ejaculate, raw and forward progressive motility of sperm cells. Both breed of boar and season of semen collection significantly influenced the ejaculate volume (p< 0.01). The Yorkshire boar showed overall superiority in quantity of semen produced when compared to Landrace boar (336.05?168.2 vs. 144.42?100.0 mls; p< 0.01). Both the percentage of motile sperm cells and raw motility estimates were not significantly affected by season of ejaculate collection (p>0.05). However, breed of boar significantly affected both the proportion of motile sperm cells and the raw motility estimates of sperm cells (p< 0.01). Mean libido scores did not differ significantly (p> 0.05) between boars (3.49?0.29 vs. 3.19?0.20; for York and Landrace boars respectively, although there was a tendency for the Landrace boar to express lower libido in summer and fall. It is envisaged that the incorporation of the results from this project would greatly enhanced widespread use of artificial Insemination as a genetic improvement tool by limited -resource swine producers.
Chukwuemeka Okere , Avis Joseph and Michael Ezekwe , 2005. Seasonal and Genotype Variations in Libido, Semen Production and Quality in Artificial Insemination Boars . Journal of Animal and Veterinary Advances, 4: 885-888.