Effect on Rendement Napole genotype on metabolic markers in Ossabaw pigs fed different levels of fat

We investigated effects of Rendement Napole (RN) genotype on metabolic markers in Ossabaw pigs fed diets with different levels of dietary fat. Thirty-two pigs, belonging to either the wild-type (WT, rn⁺ /rn⁺ ) or carrier (CAR, RN^- /rn⁺ ) genotypes (n = 16/genotype), were divided into two dietary groups, (high fat [HF] or low fat [LF]) diets, for 12 weeks (n = 8 pigs/genotype/diet) after which pigs were killed for gene expression analysis by RT-PCR. Feeding HF diet caused increased daily gain (ADG, p < .05) and final body weight (BW) (p < .05) in comparison with the LF diet (p < .05). Feed efficiency (gain:feed) was higher (p < .05) in pigs on the HF and was higher (p < .05) in CAR pigs compared to WT. There was genotype × diet interaction (p = .05) on final BW such that CAR animals on LF diet had the same final BW as animals of both genotypes on HF diet. Carrier pigs on LF diet had higher (p < .05) average daily gain and gain:feed than WT pigs. There was a trend (p < .08) for a higher feed consumption in pigs on the LF diet. Backfat thickness was higher (p < .01) in pigs on the HF diet. Serum triglyceride was higher (0.62 vs. 0.33 mg/dl, p < .01) in pigs on HF diet. Serum insulin was higher (p < .05) in CAR versus WT pigs (0.40 vs. 0.015 μg/ml). Pigs on the HF diet had a higher (p < .05) serum insulin compared to those on the LF diet (0.032 vs. 0.023 μg/ml). Carnitine palmitoyl transferase 1-alpha was higher (p < .05) in the longissimus dorsi and semitendinosus muscles of pigs on HF diet. Acyl-CoA oxidase I was elevated (p < .05) in the liver of pigs on HF diet. Fatty acid synthase was lower in the longissimus dorsi muscle, liver and mesenteric fat (p < .05) of carrier pigs. The RN gene regulates specific metabolic markers in the Ossabaw pigs.