Bovine placental lactogen invokes rapid growth in chinook salmon

Abstract

The effect of recombinant bovine placenta) lactogen (rbPL) treatment upon growth of juvenile chinook salmon, Oncorhynchus tshawytscha (Walbaum) (14.0 ± 0.31 g wet wt), was examined over a period of 6 weeks. Experimental animals were either injected (5 μg rbPL g−1 week−1), implanted with a cholesterol pellet containing 0.4 mg rbPL (approximately 4 μg g−1 week−1), or orally and rectally intubated with 7.5 μg rbPL g−1 week−1. Control animals were injected with bovine serum albumen (BSA), 5 μg g−1 week−1, implanted with a placebo or orally intubated (7.5 μg BSA g−1 week−1). Significant (P < 0.05) growth acceleration was recorded for rbPL‐injected and pellet‐implanted groups from week 2 onwards when compared against all other groups. Oral or rectal intubation of rbPL (7.5 μg rbPL g−1 week−1), however, was without effect. Condition factor decreased in all groups, but was significantly lower in rbPL‐injected and pellet‐implanted fish at trial end when compared against controls. No differences were recorded between groups for per cent body moisture or relative gut length. Hepatosomatic index was significantly (P < 0.05) higher in rbPL‐injected and rbPL‐implanted chinook salmon versus other fish.

Transgenesis changes body and head shape in Pacific salmon

“…A further indication of the flexibility of fish growth, and its morphological consequences, may be seen following treatments with exogenous hormones. For example, Pacific salmon Oncorhynchus spp., injected with growth hormone (GH) or placental lactogen experience declining condition factor (McLean et al, 1996(McLean et al, , 1997. Genetically engineered animals likewise express gross alterations in shape due to body elongation (Devlin et al, 1994(Devlin et al, , 1995a, reflecting modification to the genotype.…”

The Effects of Exogenous Bovine Growth Hormone and Placental Lactogen on Juvenile Striped Bass Morone saxatilis Feed and Growth Efficiency

“…However, Devlin et al (1994) observed a 10-20% increase in feed efficiency in bPL-treated coho salmon Oncorhynchus kisutch. McLean et al (1996) also showed that bPL accelerated growth rate in chinook salmon. Fish treated with 0.5 pg/g body weight (BW) bPL grew similarly to those treated with 5 pg/g BW bovine GH (bGH), suggesting that bPL may be superior to bGH as a growth enhancement tool.…”