Animal welfare is gaining momentum, and causing increased on-farm concerns. But occasionally something surfaces that improves animal welfare and makes economic sense.


A sow pheromone that calms piglets, reduces stress and leads to improved gains may be such a product. John McGlone, Texas Tech University animal scientist, has studied the effects of the synthetic pheromone on the activities and growth of nursery pigs.

"Pigs are olfactory animals," says McGlone. "They use their sense of smell much more than visual clues – and smells have a big effect on their behavior."

In McGlone's trials, pigs exposed to the pheromone spent more time with their head in the feeder and less time drinking, lying down and engaged in agonistic behaviors, like fighting and biting, than control pigs.

"The piglet probably finds the post-weaning environment more comfortable and familiar when the pheromone is used," says McGlone. "It also seems to produce effects that make pigs more active and more willing to eat."

McGlone studied pigs weaned between 16 and 28 days, and says the product appears to work equally well across all weaning ages. He believes the pheromone would work just as well with segregated early weaned pigs. A preliminary analysis showed no sex effects or interactions with treatment, so sex was dropped from the model.

The hypothesis for the study was that the synthetic maternal odor might intice weanling pigs to eat dry feed more quickly and in greater quantity during the difficult few hours after weaning. In turn, that might influence post-weaning pig performance and behavior.

In McGlone's study, pheromone-treated pigs were about 2.2 pounds heavier than control pigs at the end of the nursery phase. During the entire four-week, post-weaning period, average daily gain was 19 percent and 27 percent higher for two groups of pigs treated with the pheromone than for the control pigs.

The pheromone caused no significant change in feed intake, which produced an improved feed-to-gain ratio for pigs exposed to the pheromone, says McGlone. The pheromone improved the feed-to-gain ratio by 17 percent and 26 percent for the entire growth period compared with the control pigs.

In the end, the study found using the pheromone can help pigs gain an extra four pounds while in the nursery, or allow them to get to the finisher two to three days faster, depending on your management system, says McGlone.

With a quick look at finishing pigs, McGlone says the pheromone appears to stimulate feed intake slightly for about a week.

For practical use, the pheromone can be applied to the pen or feeders about an hour before moving weaned pigs in to the room. McGlone's study also looked at applying it to the pig's snout, which yielded similar results. The pheromone is not very volatile and lasts for a couple of days. By that time the pigs are usually well adjusted and continue to eat well.

"There is little labor involved," says McGlone. "It only takes about 1 ml. to 5 ml. per pig and it takes only a few minutes to spray an area for hundreds of pigs."

The synthetic pheromone used in the trial is not yet available in the United States, but is sold in Europe. The product could make its way to the states by early next year.

In Europe, the product is marketed as an animal-welfare product, because it reduces fighting, biting and stress among pigs. The product is known as a 'pig-appeasing pheromone.' Ceva Sante Animale is the company that produces and handles the pheromone, and has similar products for dogs and cats, one of which is available in the United States.

"The product itself has a lot of applications," says Uwe Haendler, North American regional manager for Ceva. "It also is used in Europe when producers co-mingle gilts and sows."

Testimonials from nursery trials in Spain showed that feed intake improved from 6.17 pounds to 7.05 pounds with one application of the pheromone on walls, floor and feeders two hours before pigs arrived in the post-weaning area. In addition, injured piglets dropped from 90 percent to 0.3 percent with the application of the pheromone, according to Haendler. Another field trial in Europe yielded an 82 percent rate of bites on piglets' shoulders for the control group and 62 percent for the treated group.

Product cost in the United States has not yet been determined, notes Haendler.

"The pheromone should be relatively inexpensive," says McGlone. "For a few cents per pig, you should be able to get several pounds of the product."

If the pheromone product lives up to research expectations, it appears to be a win/win because of its animal-welfare benefits and the productivity benefits. That would be welcome news, as not all animal-welfare driven production changes will be cost-effective.

"This appears to be a case where animal welfare and economic improvements are going in the same direction," says McGlone. "That is not always the case." 


What is a Pheromone?

Pheromones are compounds secreted by one animal that have an effect on the physiology or behavior of other animals.

Pigs have a highly developed olfactory system and probably have many pheromones that regulate their behavior and physiology, says John McGlone, Texas Tech University animal scientist.

Previous research provided evidence that maternal pheromones regulate nursing pig behaviors. Pigs would not nurse when odors were washed from the skin of the lactating sows.