Optimal age of breeding gilts and its impact on lifetime performance

In swine industry, gilts replace sows as they age for production purposes, hence continued livestock productivity highly depends on viable replacement stock. Management of these gilts early in life affects their future performance and ultimately the profitability of the swine operation. Lifetime sow performance is an important aspect in managing a commercial sow herd, and age of a gilt at first breeding is considered a management decision which affects sow lifetime performance and stayability in the herd. However with varied age range of breeding gilts practiced on various swine farms, this research aimed at understanding optimal age to first breed gilts and its impact on lifetime performance. Variables measured included, parity total born pigs, lifetime total born pigs and reason for culling. Lifetime data was evaluated of gilts breed between 1st Jan 2014 and 31st July 2016 in piglet producing herds of Midwest United States. Data was extracted from porcitec database in Dec 2018 where 15% of the sows were still active in the herds hence excluded from the analysis. A total of 17,558 removed were classified into 6 classes according to age at the first breeding in days 170-190(n=754), 191-211(n=4683), 212-232(n=7123), 233-253(n=3385), 254-274(n=1002) and 275-369 (n=611). Piglet total born obtained from each sow during the lifetime production was significant (P < 0.05) greater for gilts bred between 233-253 days of age at first mating. Gilts that were bred at <233 days appeared to have a higher risk of removal by farrowing productivity as compared to the other groups. However, the results show that the risk of being culled due to health problems and conformation issues increases as the age at first mating is delayed. Overall reproductive failure appears to be the most economical culling reason across all age groups. With this outcome, it was prudent to evaluate the best management decisions for gilt initiation in a herd to maximize her lifetime performance. Results show that gilts mated for the first time at the right age, 233–253 days, are more productive, both in lifetime total born and have a minimal risk of culling due to farrowing productivity. Furthermore inseminating gilts at second estrus proves to have an advantage of 1.57 more lifetime piglets as compared to first estrus insemination. The research therefore established that there was a significant difference (p<0.05) of age at first breeding of gilts with lifetime performance and a significant difference (p