Factors influencing number of services per conception and litter size of pigs artificially inseminated in Uganda

Abstract

Artificial insemination in pigs is currently the most promoted reproductive technology in Uganda. However, the adoption and use of the technology particularly in pigs is marred by low success rates in terms of high number of inseminations repeats for conception and small litter sizes. This study therefore was aimed at identifying the major factors that influenced the success of field artificial inseminations. A total of 376 pig insemination records from 2012 to 2019 of three pig breeds in 183 smallholder farms located in nine districts in Uganda were used in this study. Inseminations of sows and gilts was done using boar semen obtained from the national AI Boar Stud at MUARIK. The semen age (n = 4), pig type (n = 2), breed (n = 4), and sow’s body condition score (n = 5) were the factors evaluated. Correlation studies between litter size and number of services per conception were also evaluated. Pig type significantly affected litter size and number of services per conception (p = 0.032 and p = 0.014 respectively). Sow breed significantly affected number of services per conception (p = 0.009) but not litter size (p = 0.154). Age of semen and body condition score did not affect either litter size (p = 0.267 and p = 0.636 respectively) or number of services per conception (p = 0.205 and p = 0.162 respectively). Crossbred pigs required a significantly lower number of services per conception compared to other breeds. Sows gave significantly higher litter sizes than the gilts. There was no correlation between litter size and number of services per conception. Crossbreds because of their hybrid vigour, required fewer number of services whereas sows gave higher litter sizes because of the reproductive experience. Farmers should ensure pigs conceive at the first service to reduce on the production costs and increase profit margins of their piggery businesses. This can be attained through capacity building at various levels.