Breeding decisions are heavily influenced by stockperson visual evaluations of the underline, says Nikki Villalon, a veterinary student in Iowa State University’s College of Veterinary Medicine. These subjective assessments determine piglet allocation and ultimately survival.
“It’s remarkable how litter sizes have increased over the past few decades, but with that growth comes a shift in the demand for available resources, particularly functional teats,” she said at the Allen D. Leman Swine Conference. “I wanted to investigate whether those pre-farrowing assessments accurately reflected functional teats, defined as those capable of producing colostrum, especially since there is limited research validating the accuracy of these visual evaluations.”
Villalon set out to do two things: (1) to assess the accuracy of stockperson visual teat counts (“good” teats) compared to functional teats that produced colostrum at parturition, and (2) to observe the morphological characteristics of both functional and nonfunctional teats over time. She says teats that were blind or did not provide colostrum were considered non-functional while functional teats provided access to colostrum at parturition.
Prior to farrowing, stockpeople recorded the number of good teats for 22 sows. During parturition, Villalon identified functional teats using warm towel stimulation, a plastic cup for colostrum collection, and a paper mat for in pen assessments.
She recorded measurements of teat spacing (samer) and teat-to-parenchyma distance on Days 0 (pre-farrowing), 3, and 10 postpartum for morphological analysis. Sows were encouraged to lay down using positive reinforcements (apple sauce and a hand scrubber) to minimize stress and maximize measurement consistency, she says.
“Milk letdown from the sow occurs for just 10 to 15 seconds every 50 minutes, which underscores how vital accurate teat access is,” Villalon says. “Every teat counts. If an unfunctional teat is mistakenly labeled as functional, it can result in the mortality or morbidity of up to two piglets. Conversely, labeling a functional teat as nonfunctional is a missed opportunity to foster an additional piglet.”
During the study, she found discrepancies between good and functional teat counts in 40% of the sows. Teats classified as nonfunctional at Day 0 failed to gain any measurable parenchymal volume over the 10-day period. Most morphological changes occurred between Day 0 and Day 3, particularly in teat-to-parenchyma distance.
“First parity sows showed more variation and greater parenchyma growth than multiparous sows, suggesting a less consistent udder development pattern,” she adds. “These findings highlight the value of integrating objective measures like colostrum flow checks and parenchyma growth tracking into farrowing protocols.”
Although entering the pen to verify colostrum production may seem time-consuming or disruptive, Villalon says the study shows that this step can significantly impact piglet survival and sow utilization.
“A low-cost, disposable paper mat can make in-pen assessments cleaner, faster and more practical for the stockperson,” she says. “By improving the accuracy of teat assessments, producers can reduce fallback piglets, enhance piglet welfare, and improve overall herd productivity and labor efficiency.”
Villalon was one of seven finalists for the Morrison Swine Innovator Prize recognized during the Allen D. Leman Swine Conference. She presented her research findings during a session at the conference.
