Evaluation of a pregnant mares’ serum and human chorionic gonadotrophin mixture for alleviating summer infertility in sows.

The research article investigates the effect of a commercial hormone mixture on summer infertility in pigs, revealing the hormone treatment significantly reduced the interval from weaning to oestrus but had a negative impact on the number of offspring produced.

Objective and Method of the Study

• The main aim of this study was to analyze the effectiveness of a commercial gonadotrophin hormone mixture that includes pregnant mares’ serum and human chorionic gonadotrophin, in dealing with seasonal fertility decline in pigs, specifically during the summer in a sub-tropical environment.
• The testing process was a controlled on-farm trial where two groups of sows were observed – one group was treated with the hormone mixture while the other functioned as the control group and was left untreated.

Significant Findings

• The treatment was found to have a significant effect on the weaning to oestrus (fertility cycle) interval of sows. The average interval for treated sows was significantly less than that of the untreated sows, showing that the hormone treatment was effective at inducing oestrus quickly after weaning.
• However, despite the success in speeding up the fertility cycle, the treatment negatively influenced other aspects of fertility. The sows treated with the hormone mixture had lower farrowing rates (fewer sows gave birth) and produced smaller litters compared to the untreated group.

Conclusion and Interpretation

• The study concludes that although the hormone mixture succeeded in reducing the weaning to oestrus interval, it failed to increase the overall number of weaners produced due to the reduction in farrowing and litter size.
• This implies that the treatment might not be a practical solution for compensating summer infertility among pigs as the overall fertility, represented by the number of offspring produced, was not improved.