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Effects of plane of nutrition and arginine supplementation on kidney and liver mass
Objectives were to determine the effects of plane of nutrition and arginine supplementation on liver and kidney mass in non-pregnant ewes (3-5 yr of age; average BW =57.7 kg). Forty-one ewes were randomly allocated to one of three feeding groups: control (n = 14; 2.14 Mcal/kg, 14% crude protein), overfed (n = 14; 2 × control), or underfed (n = 13; 0.6 × control). Estrus was synchronized using a controlled internal drug release (CIDR) device for 14 days. At CIDR withdrawal, ewes from each dietary group were assigned to one of two treatments: Arginine (~5-10 mL L-Arg HCl, 155 µmol/kgBW) or saline (~10 mL). Treatments were administered 3 times daily for 15 days via jugular catheter beginning on day 0 of the first estrous cycle until the time of tissue collection. Ewes were euthanized via captive bolt and exsanguinated on d 15 of the estrous cycle. The liver and kidneys were immediately removed and weighed. Data were analyzed as a completely randomized design with a factorial arrangement of treatments (diet, arginine, and diet × arginine). Overfed had greater (P < 0.001) BW (71 kg), kidney weight (146 g), liver weight (998 g), and liver weight relative to BW (6.32 g of liver/kg BW) than the others diets, and control had greater BW (57 kg), kidney weight (123 g), liver weight (606 g), liver weight relative to BW (4.83 g of liver/ kg BW) than underfed (46 kg BW, 113 g kidney, 483 g liver, 4.81 g of liver/kg BW) ewes. Arginine treatment tended to increase liver weight (P = 0.07) in the overfed ewes compared to underfed and control ewes. These data indicate that plane of nutrition influences liver and kidney mass, and arginine supplementation may influence liver mass regardless of dietary group. Supported by USDA-AFRI grant 2011-67016-30174 to ATGB and DAR, Hatch Projects ND01748 to DAR and ND01712 to ATGB.
Keywords:
Arginine, liver, kidney