Location: Livestock Bio-SystemsTitle: How does body composition affect productivity
Submitted to: World Wide Web
Publication Type: Other
Publication Acceptance Date: 8/14/2018
Publication Date: 8/17/2018
Citation: Lents, C.A. 2018. How does body composition affect productivity. World Wide Web. https://www.pork.org/blog/august-2018-animal-science-webinar-series/. Available: https://www.youtube.com/watch?v=QjVnJb4sUXM&feature=youtu.be
Technical Abstract: Proper development of gilts is critical to productivity and longevity of sow herds. A complex biology underpins gilt development. Age at which a gilt reaches puberty is the first phenotypic indicator of her productive potential, and is positively associated with other indicators of fertility. Gilts that reach puberty earlier tend to stay in the herd longer and produce more pigs over their reproductive lifespan. There are age and weight thresholds that must be reached before puberty occurs, but initiation of puberty is also influenced by the relative amounts of lean and fat tissue. Genetic selection for lean growth rate is typically not associated with negative effects on reproductive performance of gilts; however, increased lean growth rates can have negative effects on the ability of a gilt to display a strong estrus. Puberty generally occurs over a wide range of lean growth rates and variation in pubertal age reflects differences in physiological maturity between individual gilts. Modern genotypes of gilts typically have little trouble achieving more than adequate growth rates and body composition. Many gilts are quite heavy at first breeding which can have detrimental impacts on longevity. Evidence suggests that gilts with slower growth rates have a greater probability of generating a second or third litter. Energy and lysine content of the diet can be reduced without negatively influencing reproductive development of gilts, thus allowing them to be bred in a more optimal weight range. Gilts tend to lose body fat and become leaner during breeding and first gestation. Gilts that do not have adequate levels of body fat at selection for breeding are at greater risk of being culled early and produce fewer litters and piglets over their lifetime. Nutritional management of body composition during breeding and first gestation represents an opportunity to improve longevity of gilts.