Effects of L-Arginine Supplementation on Performance,Serum Amino Acid Concentrations and Immune Biochemical Indexes of Lactating Sows

This study was conducted to investigate the effects of L-arginine(L-Arg) supplementation on performance,serum amino acid concentrations and immune biochemical indexes of lactating sows.A total of 32 healthy Yorkshire×Landrace sows(2 parities) with similar body weight were randomly assigned into 4 groups with 8 replicates per group and 1 sow per replicate.The sows were fed a basal diet added with 0(control group),0.8%,1.0% and 1.2% L-Arg,respectively.The experiment lasted for 21 days,which was from delivery day to day 21 of lactation(weanling).The results showed as follows: on day 10 and day 18 of the experiment,except that there was no significant difference in serum ornithine concentration between 1.0% L-Arg group and the control group(P0.05),L-Arg supplementation significantly increased serum arginine,ornithine and proline concentrations of lactating sows(P0.05 or P0.01),and there were the best results in 1.0% and 1.2% L-Arg groups among all groups.Total protein concentration in serum of lactating sows was not significantly affected by L-Arg supplementation on day 10 and day 18 of the experiment(P0.05).However,on day 10 and day 18 of the experiment,the concentrations of albumin,IgM and IgG in serum of lactating sows in L-Arg groups were significantly increased(P0.05) and serum urea nitrogen concentration of lactating sows was significantly decreased compared with the control group(P0.05),and serum urea nitrogen concentration in 1.0% L-Arg group was the lowest among all groups,but there was no significant difference in serum urea nitrogen concentration among L-Arg groups(P0.05).Weaning litter weight,piglet weight at weanling and average daily gain were significantly increased with the supplementation of L-Arg to lactating sows(P0.05),and those in 1.0% L-Arg group were the highest among all groups,but there were no significant differences among L-Arg groups(P0.05).The interval days from weanling to estrus of sows in 1.0% L-Arg group were significantly shorter than those in the other three groups(P0.05),and there were no significant differences among the control group,0.8% L-Arg group and 1.2% L-Arg group(P0.05),but those had a increasing tendency as dietary supplemental level of L-Arg increased.Regression analysis showed that serum amino acid concentrations of sows were increased linearly with the increase of dietary L-Arg supplemental level(P0.05),but performance and serum immune biochemical indexes of sows were not significant regression relation with dietary L-Arg supplemental level(P0.05).In conclusion,L-Arg supplementation can improve partial amino acid concentrations,metabolism and immune function of lactating sows so as to get a better growth performance of suckling piglets and get shorter interval days from weanling to estrus of sows.In this experiment,the optimal supplemental level in the diets for lactating sows is 1.0%.