Producers are keenly aware that mortality rates in sows have increased dramatically over the years. 
The question is why? 
There are theories, but zeroing in on the answer has stumped producers, scientists and analysts. Jennifer Brown, a research scientist in ethology at the Prairie Swine Centre in Saskatoon, is among those trying to find the cause or causes. 
“Numbers are going up and that’s an issue, especially with gilts and younger sows,” Brown told those in attendance and online at a Group Sow Housing Seminar, hosted by the Prairie Swine Centre. “Identifying causes of sow loss is a huge priority for us.” 
Brown did a survey in 2019 to try to find answers to the question. Coupled with a questionnaire sent to producers across Canada, was on-farm data collection. 
“On farms, we have a high replacement rate, removal of roughly 45 to 50 per cent per annum of the sow herd. Turnover is common and widely accepted. The concerning aspect is the mortality.” 
The mortality rate has historically been about five per cent. That has hit the 10-per-cent mark in recent years. 
“The impact is obviously the animal’s welfare and also the economics of pig production,” she said. 
Brown’s survey included 49 questions, covering such things as herd management, production levels and mortality. 
A total of 104 producers completed the survey, with 50 per cent coming from operations with herds of fewer than 500 sows. Others had as many as 3,000 sows. 
Forty-two per cent of sows were in stalls and 40 per cent in groups, and the others in a combination of the two. 
The 13 on-farm visits took place in Saskatchewan (five farms) and in Quebec (the other eight). Approximately 100 sows were part of the study in each herd. 
The morality rate in smaller operations was found to be 5.7 per cent. In larger herds, it was 10.08 per cent. 
“Larger herds have their own replacement gilt supply line and perhaps that large gilt supply at a lower cost of gilts might drive them to remove sows earlier on. But it certainly doesn’t explain the death loss side of things. 
“The general explanation is the staff workload, the turnover of staff and difficulty in training good staff in large herds might be impacting their ability to observe sows and identify problems early on and then to treat those animals properly.” 
Brown stressed that data from farms hasn’t been properly recorded. 
“Recording sow loss doesn’t seem to have that much importance for farm staff. If we could change that attitude and the importance of these numbers . . . it would really help us address the problem . . . I question the (current) data.” 
Brown pointed out mortality was found to be higher in group gestation. 
“We have heard going to groups is going to improve sow welfare, and yet we are seeing an increase in mortality in groups. What we are seeing is concerning.” 
Brown said the mortality rate is seven per cent in group housing and five per cent in stalls. 
“Within the data I have, we didn’t pull apart different systems or different management. Going forward, as we get more and more farms in groups, we really need to start pulling that apart. 
“What is effective management and how we can actually improve the welfare of sows, and their productivity in these systems?” 
Ron Ketchum, a respected American analyst who often speaks at Canadian symposiums, concurs with Brown. 
“We’ve seen sow mortality go up about a half a percent a year,” Ketchum said in May 2021. “I think a lot of it is a lack of training and lack of quality people to oversee the animals.” 
Ketchum, being quoted in PigHealthToday.com, expressed the same concern as Brown when it comes to younger animals dying at a high rate. 
“Is it something we’re not doing or something we’re doing wrong regarding gilt development or gilt selection that’s setting these young animals up not to survive? The older parities are the ones making it through the system,” he said. 
Brown again emphasized the need for reliable data. 
“I challenge each farm to try to dig into to what is going on in their specific situation. We need to standardize our reporting methods, and recognizing its importance. 
“At the end of day, this is going to help our management decisions, and obviously it is going to help someone like myself, who is trying to study sow removal reasons. Hopefully, it will help us reduce sow death . . . and improve our management and productiveness.” •
— By Cam Hutchinson