Effects Of Nicotinic Acid In Diets On Performance, Serum Antioxidant Indices And Fat Metabolism Of Growing Rex-rabbits

This paper aims to study the performance, serum antioxidant indices and fat metabolism of 3 to 5-month-old Rex-rabbits feeding with different nicotinic acid adding levels. A total of 160 3-month-old Rex-rabbits(with means of body weight 1860±144g) were divided into 4 groups(each treatment had 40 replicates) randomly. Four diets adding different doses of nicotinic acid are feeded, namely, 0mg/kg(group 1), 50mg/kg(group 2), 100mg/kg(group 3) and 200mg/kg(group 4), respectively. The experiment lasted for 60 days comprised a 7-days adaptation and 53-days data collection. The results are as follows:Diet with different nicotinic acid supplement levels has no significant effects on average daily gain, average daily feed intake, ratio of feed to gain, fur weight, fur size and wool staple length(P>0.05), while has a little effect on fur thickness(P=0.0459). The density of hair follicles, primary follicles, secondary follicle, primary follicle density / secondary follicle density are affected significantly(P<0.01) by adding different doses of nicotinic acid, the second group and the third group are significantly higher than the density of the first group and the fourth groups. The glutathione peroxidase, total superoxide dismutase and malondialdehyde in serum were not affected by nicotinic acid adding. There are no effects on L、a*、pH24、drip loss and pressure loss of meat(P>0.05), but significant effects on b* of meat(P=0.0014), and the third group are very lower than others. The content of cholesterol(P<0.0001), free fatty acid(P<0.0001), adiponcetion(P=0.0324), ApoB(P=0.0023), high-density lipoprotein(P=0.0002) and activity of MDH(P=0.0210), LPL(P<0.0001) in blood are affected by different levels of nicotinic acid significantly, but other indices include total protein, ApoA, triglyceride, estradiol, leptin, insulin, low density lipoprotein cholesterol and very low density lipoprotein cholesterowere are not affected(P>0.05). There are different effects on the activity of MDH(P>0.05) and FAS(P=0.0428) in liver. The expression of adipoR1, adipoR2, insulin reception, ACC, CPT are decreased in different extent, especially adipoR2(P=0.0129) and ACC(P=0.0011).