Effects of a high carbohydrate diet and arginine supplementation during the rearing period of gilts on osteochondrosis prevalence at slaughter

• Effects of dietary carbohydrate and arginine levels on osteochondrosis (OC).
• Carbohydrate diet affected glucose, insulin, IGF-1, and nitric oxide levels.
• Carbohydrate diets associated with lower body weight development.
• Carbohydrate high diets associated with lower OC prevalence.
• OC prevalence likely affected by body weight development affected by diet.

Osteochondrosis (OC) is a consequence of necrotic growth cartilage formation early in life and suggested to be associated with lameness and premature culling of sows. Higher insulin, glucose, and insulin-like growth factor-1 (IGF-1) are associated with increased OC in horses and are affected by carbohydrates. If dietary composition can affect OC through metabolic parameters in sows, it could be a tool in practice to reduce OC prevalence. This study examined if OC prevalence in rearing gilts can be influenced by dietary carbohydrates and/or arginine by affecting IGF-1, insulin, glucose, and nitric oxide (NO) levels. Gilts (n=212; Dutch Large White x Dutch Landrace) were acquired after weaning (4 weeks of age). At 6 weeks of age, gilts were subjected to a 2×2 factorial treatment design of dietary carbohydrate and arginine level scale fed at pen level. Carbohydrate level consisted of 12.5% cornstarch and 12.5% dextrose added to a basal diet (C+) versus an isocaloric diet in which cornstarch and dextrose were replaced with 8.9% soya bean oil (C−). Arginine supplementation consisted of 0.8% arginine supplemented to a basal diet (A+) versus 1.64% alanine as the isonitrogenous control (A−). At 24 weeks of age, blood samples of in total 34 gilts around feeding were taken and assessed for insulin, glucose, IGF-1, and NO levels. After slaughter at 25 weeks of age, OC was scored on the elbow, knee, and hock joints. Gilts in the C− treatment had higher glucose and insulin levels 90 min after feeding onwards and higher IGF-1 levels than gilts in the C+ treatment (P<0.05). Arginine supplementation did not significantly affect metabolic parameters. Arginine supplementation tended to decrease OC prevalence (P=0.07) at the animal level (all joints combined) and in the knee joint. Carbohydrate treatment affected prevalence of OC only in the knee joint in which gilts in the C− treatment had a higher odds ratio (OR) to have OC (OR=2.05, CI: 1.18–3.58) than gilts in the C+ treatment. Additionally, body weight at slaughter was significant when added to the statistical model (P<0.01) in the knee joint and the animal level (per 10 kg increase OR=1.33, CI=1.11–1.6 and OR=1.17, CI=1.05–1.31, respectively). This study found effects of carbohydrates on OC prevalence in gilts at slaughter. The dietary treatment effects found in the current study likely have been mediated through effects on body weight.