Effects of bovine growth hormone (Posilac®) on growth performance, body composition, and IGFBPs in two strains of channel catfish

The effects of recombinant bovine growth hormone (rbGH; Posilac®) on growth rate, feed efficiency, body composition, and insulin-like growth factor binding proteins (IGFBPs) were investigated in Norris and NWAC103 strains of channel catfish. Three hundred and twenty fish from each strain were assigned randomly to four treatments with four replicates each. The treatments were (1) Sham-injected control (needle puncture per 3 weeks); (2) Low (30 μg g −1 BW per 3 weeks, Posilac®); (3) Medium (60 μg g −1 BW per 3 weeks, Posilac®); and (4) High (120 μg g −1 BW per 3 weeks, Posilac®). Fish were reared in 76-l tanks supplied with 26.0 °C flow-through well water for 9 weeks. Fish were fed a 36% CP commercial diet twice each day to apparent satiation. Feed consumption increased ( P