title: Growth enhancement following dietary delivery of recombinant porcine somatotropin to diploid and triploid coho salmon (Oncorhynchus kisutch).
abstract: Diploid (2n) and triploid (3n) coho salmon were fed upon control (diet 1), recombinant porcine somatotropin (rpST)-supplemented (diet 2; 20 μg rpST/g body wt/day) or rpST/antacid/detergent-containing feed (diet 3; 20, 100 & 20 μg/g body wt/day respectively) for 16 wk. Fish were weighed and measured bimonthly and their relative performances assessed. By wk 4, 2n and 3n groups fed upon diet 2 were significantly heavier and longer than control 2n fish. At the termination of the trial, diet 3 fed animals were greater in weight than all other treatment groups. Diet 3 salmon also returned better feed conversion efficiencies than either diet 1 or 2 groups. RpST therapy induced a 28.7% and 60.2% increase in group wt for 3n diet 2/3 coho versus (-vs-) controls. Likewise, 2n rpST-treated fish increased wt -vs-2n control coho by 17% and 50% respectively over the same period. No differences were recorded between groups for body moisture, but diet 2, 3n and both diet 3 groups exhibited decreased condition factors when compared to control fish (p ≤ 0.05).
authors.affiliation: Biotechnology, Genetics & Nutrition Section, West Vancouver Laboratory, 4160 Marine Drive, West Vancouver, B.C., V7V 1N6, Canada.
authors.forename: E
authors.initials: E
authors.lastname: McLean
authors.forename: E M
authors.initials: EM
authors.lastname: Donaldson
authors.forename: E
authors.initials: E
authors.lastname: Teskeredzic
authors.forename: L M
authors.initials: LM
authors.lastname: Souza