Genetically reducing sow stress

Dec 09, 2019

Genomic researchers are working with swine sector experts to assess whether selecting for reduced stress in sows can lead to greater piglet survivability

By Jackie Clark
Staff Writer
Farms.com

Thanks to an investment from the Ontario Regional Priorities Partnership Program, Dr. Ray Lu of the department of molecular and cellular biology at the University of Guelph, and Alliance Genetics Canada (AGC) are trying to target stress reduction in sows to improve piglet survival rates.

“Before we were looking at stress impact on growth, meat quality, and feed conversion,” Lu told Farms.com. Upon teaming up with Dave Vandenbroek, CEO of AGC, and Brent Devries, customer sales and service representative at AGC, Lu asked “What are the problems that happen on the farm that need solutions?”

Vandenbroek and Devries pointed to pre-weaning mortality as an aspect of the swine sector that could be improved.

“Piglet mortality has a big effect on our customers and our producers in the industry. Many factors lead to survivability,” Vandenbroek told Farms.com. “If we can reduce pre-weaning mortality by selecting for genes related to (reducing) stress within sows, it’s going to help our customers.”

The Ontario pork industry loses $12.9 million from piglets to crushed or savaged by sows.

Given the amount of money at stake, “even if genetic factors are only 5 to 10 per cent (of the reason) behind piglet loss, that is still a huge economic gain if we can help increase survivability,” Lu said.

Lu is using two genetic techniques in his work. The first technique is a broad genomic approach of looking at all genes that may have the potential to affect stress.

Researchers are “trying to validate the things we found in mice,” he explained. Genes that indicate stress tend to be similar in mammals, so mouse-based research can help scientists locate stress genes in pigs.

The second technique is what Lu calls a “targeted genomic approach,” which works with a “more precise marker panel to accurately predict stress in pigs,” he said.

“I think the two methods can complement each other,” he added.

Lu explained the necessity of involving producers and industry experts to translate learning from a controlled experimental setting to commercial swine barns.

The goal is to develop “genetic tools, but also practical, on-farm stress evaluations” to assess which sows will be more likely to have maternal traits that increase piglet survivability, he explained.

This research may offer additional benefits for the swine sector.

“We can collect the data and look at other economically beneficial traits,” Vandenbroek said. Genetically controlling stress traits in sows may contribute to a larger litter size, increased milk production or greater weaning weight.

The Ontario Regional Priorities Partnership Program awarded seven projects at the University of Guelph a total of over $2.5 million for genomics research in the agriculture and agri-food industry.

chayakorn lotongkum\iStock\Getty Images Plus photo

Video: US Soy: Pig growth is impaired by soybean meal displacement in the diet

Eric van Heugten, PhD, professor and swine extension specialist at North Carolina State University, recently spoke at the Iowa Swine Day Pre-Conference Symposium, titled Soybean Meal 360°: Expanding our horizons through discoveries and field-proven feeding strategies for improving pork production. The event was sponsored by Iowa State University and U.S. Soy.

Soybean meal offers pig producers a high-value proposition. It’s a high-quality protein source, providing essential and non-essential amino acids to the pig that are highly digestible and palatable. Studies now show that soybean meal provides higher net energy than current National Research Council (NRC) requirements. Plus, soybean meal offers health benefits such as isoflavones and antioxidants as well as benefits with respiratory diseases such as porcine reproductive and respiratory syndrome (PRRS).

One of several ingredients that compete with the inclusion of soybean meal in pig diets is dried distillers grains with solubles (DDGS).

“With DDGS, we typically see more variable responses because of the quality differences depending on which plant it comes from,” said Dr. van Heugten. “At very high levels, we often see a reduction in performance especially with feed intake which can have negative consequences on pig performance, especially in the summer months when feed intake is already low and gaining weight is at a premium to get them to market.”

Over the last few decades, the industry has also seen the increased inclusion of crystalline amino acids in pig diets.

“We started with lysine at about 3 lbs. per ton in the diet, and then we added methionine and threonine to go to 6 to 8 lbs. per ton,” he said. “Now we have tryptophan, isoleucine and valine and can go to 12 to 15 lbs. per ton. All of these, when price competitive, are formulated into the diet and are displacing soybean meal which also removes the potential health benefits that soybean meal provides.”