#15-179

Complete

Date Full Report Received

10/13/2017

Date Abstract Report Received

10/13/2017

Investigation

Institution:
Primary Investigator: ,
Co-Investigators: Aileen F. Keating, Lance Baumgard

Gilt and sow management play a key part in improving system production efficiency. Current industry estimates for sow turnover rate range from 40-50% (PigChamp year-end review 2000-2015), with a disproportionate percentage of younger parity sows culled in transition from their first and second parity. High turnover rates result in reduction of the average productive life expectancy of the herd, and increase overhead costs to production. Furthermore, increases in average mortality have been observed in past five years. Thus, if a sow can make it to breeding for her 3rd parity and produce 30 pigs, she may only provide a market return of 80% of the offspring produced, when considering 13% average pre-wean mortality per litter, and 6% average post wean mortality (National Pork Board, 2012). Nutrition during gestation, heat stress management, and gilt selection are areas of gilt and sow management that can be linked to reproductive and performance efficiency of the herd. Understanding the application, physiology, and incidence of parameters that affect these areas of management, have the potential to improve herd performance. These projects provided insight and understanding of sow management and its effect on herd reproductive efficiency through utilization of knowledge on physiology in management, as well as insight into practical application of the knowledge gained.

Take home message for U.S. pork producers regarding this proposal:
Production of animal proteins is an important industry within the United States and the global economy, particularly for pork which makes up 40% of all animal protein consumed globally (OECD) and contributing $39 billion to the GDP (National Pork Producers Council, pork-facts page, 10-2-2017). Inadequate performance of the reproductive herd reduces the productive output of the swine industry at every level of pig production. Increasing our understanding of gilt and sow physiological challenges during her lifetime can improve management of the sow herd, and potentially increase the productivity of downstream pig production in the terminal herd. Improving gilt selection, gestation nutrition, and our understanding of the effects of heat stress on reproduction represent areas of tremendous opportunity for swine producers to improve whole system production. These research projects have contributed valuable information into increasing our understanding of swine management and reproductive physiology under commercial conditions.

Objective 1
♦ Maternal supplementation of arginine during gilt gestation did not improve litter size under current conventional pig production system conditions.
♦ Maternal supplementation of arginine fed late in gestation may improve piglet wean weight and gain during gestation, however effects are not visualized at market, highlighting the complexity of maternal influence on offspring performance.
Objective 2
♦ Heat stress causes an increase in autophagy markers in the pig ovary, a sign increased cellular stress and reduced function.
♦ Anti-apoptotic signaling is increased in the pig ovary under heat stress conditions, indicating that cells remain in prolonged stress, but do not die.
Objective 3
♦ Early prepubertal reproductive tract development is associated with improved reproductive performance.
♦ Gilts average or above for vulva width at 15 weeks of age, have an increased likelihood of achieving parity one, and produce more piglets through two parities.