The effects of exogenous bovine growth hormone and placental lactogen on juvenile striped bass Morone saxatilis feed and growth efficiency.

Striped bass Morone saxatilis under normal pond-reared conditions usually requires 14–18 mo to grow out to market weight. This includes a winter of comparatively slower growth which could possibly be overcome through hormonally induced acceleration of growth. Thus, the objective of this experiment was to test the hypothesis that bovine growth hormone and bovine placental lactogen increase growth in striped bass in a dose dependent manner. A secondary objective was to determine the effect of these hormones on body composition. Variables tested were weight gain, length gain, condition factor, feed conversion, and body composition. Fish injected biweekly with 10 μg/g body weight, bovine placental lactogen (P < 0.09) or bovine growth hormone (P < 0.11) increased body weight. Fish injected with 1 or 10 μg/g body weight bovine placental lactogen (P < 0.10) or bovine growth hormone (P < 0.10) increased body length during the 12-wk study period. Proximate analysis indicated that bovine growth hormone increased protein content (10 μg/g; P < 0.10) and decreased fat content (1 and 10 μg/g; P < 0.10). No significant differences occurred in feed conversions. We conclude that bovine growth hormone and bovine placental lactogen are effective in increasing body growth in striped bass.