Pain meds in milk could calm piglets

"We wanted to find out if we can deliver medications to the piglets passively without having to handle and inject each one individually," says Hans Coetze. "Our results seem to demonstrate that this method has the potential to dramatically change how piglets are treated." (Credit: Morgan/Flickr)

Delivering pain medication to piglets through their mothers’ milk could ease the stress they experience after being castrated or having their tails removed.

Consumers are concerned about pain management during routine animal husbandry procedures, so researchers began studying the possibility of introducing pain medication into the feed of a sow, which would then pass it on to her piglets through her milk, eliminating the need to give the piglet an injection.

cranial temperature of piglets
These images taken with a thermography camera show a piglet treated with a pain medication on the left and a piglet given a placebo on the right. The piglet on the right displays a cooler cranial temperature. (Courtesy: Hans Coetzee )

The year-long study shows that piglets that receive the pain medication through the milk of a medicated sow experience less stress following castration and tail docking than piglets nursed on sows that didn’t receive the medication.

“We wanted to find out if we can deliver medications to the piglets passively without having to handle and inject each one individually,” says Hans Coetzee, professor of veterinary diagnostic and production animal medicine at Iowa State.

“Our results seem to demonstrate that this method has the potential to dramatically change how piglets are treated.”

The practices of removing the tails of piglets and castrating males are common in US pork production, he says. Castrating males before they reach sexual maturity stops pork from developing an unpleasant taste referred to as “boar taint.” It also lowers the level of aggression that male pigs may demonstrate.

Docking reduces the possibility of pigs biting the tails of their pen-mates, causing pain and potentially serious injury.

Skin temperature changes

The European Union requires pork producers to administer pain medication to piglets before carrying out these procedures, but the United States hasn’t enacted a similar measure. In fact, the Food and Drug Administration hasn’t approved the use of any pain medication for piglets, Coetzee says.

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So how do the researchers know the piglets in the study are responding to the medication?

For the study, published in PLOS ONE, researchers tracked the level of the medication in blood samples taken from both the sows and piglets involved in the study. They also used a thermography camera to measure changes in skin temperature on the heads of the piglets after they underwent castration and docking.

The images showed that piglets nursing unmedicated sows typically had a pronounced drop in surface temperature around their heads, likely resulting from pain causing blood vessels in the skin to constrict and reduce blood flow.

On the other hand, piglets that received the pain medication through the milk maintained a more consistent surface skin temperature, an indication that those piglets were under less stress.

The researchers used meloxicam in the study, a non-steroidal anti-inflammatory medication similar to aspirin. The next step in the research is to determine the lowest dose of medicine that can be given to a sow that still produces the desired amount of pain mitigation in piglets.

“We have to refine the process and make it cost effective, because this method has immense potential in assisting the swine industry in addressing pain associated with routine management procedures,” Coetzee says. “It’s possible it could be used for other drugs a producer might want to use to medicate piglets.”

The Iowa Livestock Health Advisory Council and the US Department of Agriculture’s National Institute of Food and Agriculture funded the study.

Source: Iowa State University