Vitamin inadequacies are being ignored in swine management because of misunderstandings in sow-culling reports, some nutritional experts think.
“Producers check (off) what they see last,” said Iowa State University nutritional researcher Ken Stalder at the World Pork Expo.
“The primary reason often doesn’t get recorded in their reporting systems.”
Many North American sow herds have “unacceptable” cull rates for sows, with 55 to 65 per cent replacement rates within herds.
The most commonly noted reason is “reproductive failure,” but Stalder thinks that masks the true cause for many cases.
Some sows might have problems with their reproductive systems, but others aren’t breeding or carrying fetuses to term because of feet and leg problems.
“If a sow has poor feet and legs and she doesn’t want to stand up and eat in farrowing, she’s obviously going to get thin. If she gets thin, when she gets weaned she may not cycle in a timely manner.
“If she doesn’t cycle in a timely manner, she may not cycle at all. If she cycles she may not conceive, or if she conceives she may not hold that litter until she farrows.”
Stalder said research he was involved with revealed 85 per cent of cull sows inspected at a packing plant had at least one foot lesion.
The connection to vitamin consumption comes from the importance of vitamins to pig leg and foot health. Without optimal nutrition, sows and other pigs can develop foot and back problems.
In sows, that can lead to poor reproductive performance, but if foot and leg problems are not recorded or realized to be a cause at time of culling, it can be a hidden problem.
“Vitamin D is very critical in developing good bone structure,” said Stalder.