[Edited version of a paper presented by Cara Haden, DVM, Pipestone Veterinary Services, Minnesota, during the 2024 Annual Meeting of the American Association of Swine Veterinarians]

In 2022, the US swine industry hit a five-year pre-weaning mortality high of 14.4%. The trend of increasing pre-weaning mortality has been identified as a significant barrier to both the industry’s welfare and sustainability goals. Pre-weaning mortality is complex. There are several genetic, health, environmental, facility and management factors that impact pre-weaning mortality.

Piglet movement

Piglet movement from the dam to the foster sow is a regular production practice on many US farms. Piglets are moved for a variety of reasons, ranging from attempts to save starving piglets, to finding a teat for piglets when live born is greater than the teats available to nurse.

Within the first several days of life, piglets are establishing teat order, piglet hierarchy, and learning to understand the grunting patterns which communicate laying and nursing behaviors of their dams. As piglets are moved to new dams, hierarchy, teat order and grunting pattens need to be relearned and piglets are exposed to new environments possibly containing new pathogens. Each time piglets are moved there are health and behavioral implications.

In work done by Dr. Gustavo Pizarro at Pipestone, litters that remained intact on their own dam at initial cross fostering had statistically significant lower pre-weaning mortality compared to litters where piglets were not left on their dams.

Fully intact litters had 10.54% pre-wean mortality. Litters where piglets were removed, but not added, had 10.50% mortality. Litters with low live born where additional piglets were added averaged 10.88% mortality and litters where all piglets in the litter were placed on a new sow had a pre-weaning mortality of 12.55%.

As producers seek to reduce preweaning mortality, the behavior and health implications of pig movements should be considered.

Confirming colostrum intake

Colostrum intake is a main indicator of piglet survivability. Colostrum plays a vital role in energy, thermoregulation, immunity and immune function. Many farms utilize production practices such as drying and split suckling, which aim to increase colostrum intake.

Few farms measure successful colostrum intake in real time on the farm.

As piglets consume colostrum, their metabolic rate increases which raises and maintains body temperature. A piglet with an appropriate body temperature has likely consumed adequate colostrum. Given appropriate environmental conditions, a piglet with an inappropriate temperature may indicate inadequate colostrum intake. When piglet temperature is monitored in real time, actions can be taken to ensure colostrum intake prior to gut closure.

Early work with thermal cameras has suggested it may be a helpful tool at identifying colostrum deprived piglets when farrowing rooms are cool. Unfortunately, in hotter temperatures thermal imaging can’t distinguish between colostrum deprived piglets and those that consumed appropriate colostrum. Continued work is needed to help caregivers verify colostrum consumption.

Real time tracking

Historically, pig farms have utilized production record packets which come out weekly and contain production information from the previous week. The lag between timing of pre-weaning mortality and production record availability does not allow for timely recognition of concerns or timely intervention. However, there is now technology available that can provide real time pre-weaning mortality tracking, which allows for the immediate recognition of problems. 

Pre-weaning mortality is a barrier to improving pig welfare and sustainability of US pig farms. Accepting an ever-increasing mortality rate in piglets is not an option. All veterinarians and farmers need to evaluate the role genetics, health, environmental and facility management play on their current pre-weaning mortality. The focus should be on the evaluation of pig movements, confirmation of colostrum intake and real time tracking of pre-weaning mortality.