Effects of coated cysteamine on growth performance, carcass meat and metabolism in finishing pigs

This study was conducted to evaluate the effects of coated cysteamine (CCS) on growth performance, carcass characteristics, meat quality, and lipid metabolism in finishing pigs. A total of 160 pigs (62.12 +/- 1.43 kg body weight) were randomly divided into 4 groups, with 4 pens per group and 10 pigs (5 gilts and 5 barrows) per pen. Pigs were fed a basal diet supplemented with 0, 100, 200, or 400 mg/kg CCS, corresponding to 0, 27, 54, or 108 mg/kg cysteamine, respectively. All pigs were given free access to feed and water for forty days. Average daily gain, average daily feed intake and feed to gain ratio were not affected by the CCS treatment. Supplemental CCS increased carcass lean ratio linearly (P<0.05) and longissmus muscle area quadratically (P<0.05), and the water-holding capacity as measured by 24 h drip loss was quadratically affected (P<0.05) by CCS supplementation. The activity of hormone-sensitive lipase in subcutaneous adipose tissue was linearly increased (P<0.001), while fatty acid synthase activity was linearly decreased (P<0.05). Pigs fed CCS had a lower serum triacylglycerol (P<0.001) level and lipase activity (P<0.001), lower total cholesterol (P<0.05) level, and a higher total protein (P<0.001) and free fatty acids (P<0.01) levels. In addition, CCS quadratically increased serum growth hormone (GH) (P<0.001) level and quadratically affected somatostatin (SS) (P<0.05) level. Consistently, significant effects of dietary CCS were observed on the mRNA expression of GH and SS in the anterior pituitary gland and the hypothalamus, respectively, where the intermediate CCS level showed the highest GH mRNA level and lowest SS mRNA level. The results indicate that dietary supplementation of CCS has beneficial effects on carcass characteristics and meat quality, and affects lipid metabolism in finishing pigs.