The potency of signal transducers and activators of transcription (STAT) protein as a growth promoter candidate for broilers

The long-term objective of this study was to produce STAT synthetic protein in broilers during growth period resulting from the increase of growth hormone (GH) as growth promoter. This study used ten male broilers Lohman (MB 202 P) from PT. Multibreeder Indonesia Tbk. The broilers were kept in batteried cages, with a capacity of one broiler in each cage. The broilers were fed twice a day, at 6 a.m. and 6 p.m. with the amount of feed 10% less than standard. At day 21 the broilers were sacrificed to obtain the samples, i.e., adipose tissue, liver and muscles (Mfemoralis and M pectoralis) for the following examinations: (1) isolation of STAT-1 and STAT-3 signaling protein from adipose tissue, liver, and muscles (M. femorolis and M. pectoralis) of the broilers, (2) analysis of STAT-1 and STAT-3 signaling protein from adipose tissue, liver, and muscles (M. femorolis and M.pectoralis) of the broilers using SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis) method, and (3)identification of STAT-l and STAT-3 signaling protein using Western Blot method by means of protein detection using electrophoresis with polyacrylamide gels. Results of examination on protein in hepatic tissue, muscle and adipose tissue of broilers in growth period using dot blot revealed that STAT protein was positively present in those tissues. This finding was followed-up with SDS-PAGE examination, from which we found the presence of protein band between the markers of 116 kDa and 14.4 kDa. The protein band was supposedly the STAT-1and STAT-3 protein. To prove that protein band formed was the STAT-1and STAT-3, Western Blot examination was conducted using rabbit polyclonal antibody STAT-1 and STAT-3. The result showed the formation of the protein band, indicating the presence of reaction between antigens (STAT-1 and STAT-3 protein) and STAT 1 and STAT-3 protein antibodies. In conclusion, STAT 1 and STAT-3 protein is present in hepatic, muscular and adipose tissues, with molecular weight of 59.3 kDa and 59.4 kDa, respectively.