A University of Kentucky reproductive biologist announced on Apr. 30 a four-year study to examine the growing problem of uterine crowding in commercial swine, an issue linked to higher pre-weaning mortality and lower growth rates among piglets.
The research, led by Jonathan Pasternak, associate professor in the Department of Animal and Food Sciences at the Martin-Gatton College of Agriculture, Food and Environment, is supported by a $650,000 grant from the U.S. Department of Agriculture National Institute of Food and Agriculture. The project aims to identify how increased litter sizes have outpaced sows’ ability to support their offspring during pregnancy.
Decades of genetic selection have resulted in larger litters—now averaging nearly 16 piglets—but sows’ uterine capacity has not kept up. “Ovulation rate is exceptionally heritable, but uterine capacity can’t keep pace,” Pasternak said. “We now have sows producing more piglets in a litter than they have nipples to nurse them.” This mismatch leads to intrauterine growth restriction (IUGR), where piglets with full genetic potential for growth are deprived of nutrients before birth. According to Pasternak, “From a pure reproductive standpoint, this is arguably the biggest issue facing the swine industry today.”
Researchers will track fetal development at different stages and investigate why some piglets resist crowding effects better than others. The findings could help producers select animals that maintain high litter sizes without sacrificing animal welfare or economic performance due to IUGR. “We’re never going back on litter size,” Pasternak said. “The goal is to perhaps inform the geneticists of what the limits of uterine capacity really are and find ways to maintain litter size while avoiding these low-quality piglets that won’t perform as desired.”
The Martin-Gatton College supports this work through its facilities such as teaching labs and research centers according to its official website. The college receives over $48.7 million annually in external research funding and awards more than $1.2 million each year in scholarships according to its official website. It includes more than 2,600 students and reaches about 4.8 million contacts through its programs according to its official website.
As part of the University’s land-grant system according to its official website, the college works toward serving local communities as well as global ones through education, outreach, research, and service aimed at improving lives and ensuring sustainability according to its official website. Its mission also includes advancing social impact both within Kentucky and internationally via graduates and programs according to its official website.
Pasternak hopes that tissue samples collected during this project will be valuable for other researchers studying similar issues across species: “IUGR is also a human health issue, so the samples we’re generating are likely to be valuable to other researchers at UK and beyond,” he said.
