Abstract
Age at first breeding and lifetime reproductive performance was analyzed on 17,558 F1 Landrace x Yorkshire gilts from 9 piglet producing herds of Midwest, United States entered in herds between 1st Jan 2014 and 31st July 2016. At the time of data collection Dec 2018, 15% of the sows were still active in the herds hence excluded from the analysis. Individual gilt data included date of birth, age in days at first mating, piglet total born by parity, lifetime piglet total born and reason for culling. Quality data checks were done before analysis to eliminate all outlier values together with sows that had no entry information for any listed category. The total database of the sows was classified into 6 classes according to age at the first mating 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 significantly (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. There is a need to evaluate the best management decisions for gilt initiation in a herd to maximize her lifetime performance. The results indicate 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.
Highlights
Modern swine production has benefited from a large amount of research that greatly influences lifetime sow performance
To be included in the present study, herds had to be free from incidences of Porcine Reproductive and Respiratory Syndrome (PPRS) and Porcine Epidemic Diarrhea (PED) which have been found to be the most economical diseases affecting swine industry in the US (Holtkamp et al, 2013).The herds were selected on their merit of completeness and accuracy of recording data
Age at first breeding of gilts has consequences on reproductive performance and longevity. This has been demonstrated by the fact that breeding at 233–253 days appears to be the optimal age for sow increased lifetime total born piglets and reduced sow culling by farrowing productivity
Summary
Modern swine production has benefited from a large amount of research that greatly influences lifetime sow performance. One of the most critical factors driving the performance of sow herds is gilt management. Decisions regarding gilts have profound effects on sows’ lifetime performance. Lifetime performance is normally assessed by the average productivity of the sows or the number of piglets born per sow for the entirety of her life in the herd Koketsu (2007). Lifetime sow performance is a critical indicator for producers managing a commercial sow herd. Increased lifetime performance and longevity in sows reduces costs of replacement gilts and improves herd performance and profitability Sasaki et al (2008)
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