Dietary L‐arginine supplementation affects immune status of pregnant gilts

This study was conducted to determine the effect of dietary L‐arginine supplementation on the immune status of pregnant gilts. A total of 53 pregnant gilts with an initial body weight of 166.25+1.81 kg and backfat thickness of 13.26+0.21 mm were housed individually in gestation crates. At d 30 of gestation, gilts were assigned randomly to corn‐ and soybean‐based diets supplemented with 1.0 % L‐arginine (treatment group) or 1.7 % L‐alanine (isonitrogenous control). Both diets contained 3.1 Mcal ME/kg and 12.2% CP. Gilts were fed 1 kg of the diet twice a day at 0700 and at 1700 h during the gestation period. Blood samples were collected at 0900 on d 30, 50, 70, 90 and 110 d of gestation. Whole blood samples were used for hematological analysis as determined by CELL‐DYN®. The numbers of white blood cells, neutrophil, basophil, eosinophil, monocytes, and total lymphocytes did not differ (P>0.05) between the control and treatment groups at d 30, 50, 70, and 90 of gestation. However, compared with the control group, arginine supplementation increased the numbers of white blood cell (P=0.013), neutrophil (P=0.007) and basophil (P=0.011) at 110 d of gestation. These results demonstrate the L‐arginine supplementation at 1% affects immune cell populations of first parity sows.