Tail biting increases if hogs are on a low-protein ration, reports veterinarian Hannah Jansen of Southwest Ontario Veterinary Services.
She outlines her work and Netherlands research on a posting on the Swineweb internet site.
Pigs that are fed low protein diets may spend increased amounts of time investigating their environment and foraging for food in an effort to find what they are lacking, she said.
On the other hand, lowering protein is associated with reduced rates of diarrhea among newly-weaned hogs.
When environmental enrichment is very poor the pigs may increasingly redirect their behaviours towards pen mates. If the act of “nibbling” on a penmate should happen to produce some blood the pigs will become very interested in the blood since it can be an easy source of amino acids and other nutrients that are missing from the diet, Jansen wrote.
They found that:
Hogs on a low-protein diet had a lower feed intake, growth, and gain-to-feed ratio, and were more active than hogs on a normal ration or those on a low-protein diet supplemented with amino acids.
Those on the low-protein diet interacted most often with enrichment materials, such as hanging ropes.
Low-protein pigs showed more tail biting.
Adding amino acids and extra toys reduced tail biting in the starter phase. but did not help in grower or finisher phases.
Dr, Jansen said this study done in the Netherlands confirms previous findings that pigs that are fed low crude protein rations can be at greater risk of tail biting behaviour.