Mitigating Tail Biting in Pigs: Amino Acid Supplementation vs. Environmental Enrichment By Hannah Jansen DVM Southwest Ontario Veterinary Services

Some European producers have elected to formulate relatively low crude protein diets in an effort to reduce environmental nitrogen excretion (pollution). In addition. lowering crude protein is believed to reduce hind gut fermentation of undigested protein that can increase the risk of post-weaning scour. 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. 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. These Dutch researchers investigated the effect of supplementing a low protein diet with indispensable (essential) amino acids (IAA) or providing additional environmental enrichment on tail biting. Undocked pigs (n = 48 groups of 12) received either a normal protein diet (NP), a low protein diet (LP), an LP diet with supplemented IAA (LP+), or LP diet with extra environmental enrichment (LP-E+) during the starter, grower, and finisher phase. All treatments in the nursery phase had a jute bag (1.1 × 0.6 m) and a rope (2.85 m in length) that was standard enrichment. The extra environmental enrichment consisted of a rope (2.85 m in length, with three nodes), a wooden beam (1 × 0.095 × 0.045 m) hanging from the pen walls with metal chains, and a provision of 350 g of chopped straw (approximately 15 cm long) per day.