The effects of dose and method of administration of biosynthetic bovine somatotropin on live-weight gain, carcass composition and wool growth in young lambs

Abstract

1987). The effects of dose and method of administration of biosynthetic bovine somatotropin on live-weight gain, carcass composition and wool growth in young lambs. ABSTRACT Exogenous bovine pituitary somatotropin (GH) can influence markedly body composition in fattening lambs. However, neither the effects of biosynthetic somatotropin nor the effects of dose and method of administration have been reported. Fifty Dorset-cross lambs (female and castrated male) were given concentrate ad libitum and treated between 10 and 22 weeks of age with biosynthetic bovine somatotropin either dissolved in buffer and injected subcutaneously (s.c.) in proportion to body weight (0-025, 0-1 or 0-25 mg/kg per day), dissolved in buffer and continuously infused s.c. (0-1 mg/kg per day) or suspended in olive oil and injected s.c. (0-1 mg/kg per day), and compared with 10 untreated control lambs. Somatotropin had little effect on live-weight gain (controls = 228 g/day; final live weight 37 kg), food intake and food conversion efficiency, and only marginally increased the weight of muscle and bone dissected from the shoulder joint. The weights of the major fat depots in the abdominal cavity and of fat dissected from the shoulder joint were linearly related to dose of somatotropin (P < 0-001). Lambs given the highest dose had less visceral fat (1-18 v. 2-84 kg; P < 0-001) and proportionately less fat (285 v. 374 g/kg; P < 0-001) and more muscle (542 v. 447 g/kg) and bone (172 v. 149 g/kg; P < 0-001) in the shoulder joint than control lambs. There was a positive curvilinear relationship (P < 0-01) between clean wool growth (mid-side patch sample) and dose; lambs injected daily with 0-1 mg somatotropin per kg grew one-third more wool than control lambs. Method of administration affected plasma somatotropin profiles but had no significant influence on any of the responses measured. The anabolic actions of somatotropin may have been limited in this experiment by a low sodium concentration in the diet. It is concluded that the lipolytic/anti-lipogenic effect of somatotropin can occur in the absence of conditions conducive to the stimulation of muscle protein deposition and that the response is dose dependent but not influenced by method of administration of the hormone.

Influence of nutrition and bovine growth hormone (GH) on hepatic GH binding, insulin-like growth factor-I and growth of lambs

“…Growth hormone (GH), when administered to sheep, often causes a small increase in body weight and a significant decrease in carcass fat, with an associated increase in muscle (Wagner & Veenhuizen, 1978;Johnsson, Hathorn, Wilde et al 1987). This response is dose dependent (J. J.…”

Respons Pertumbuhan Dan Keragaan Darah Dari Tiga Strain Ikan Nila Terhadap Pemberian Hormon Pertumbuhan Rekombinan Ikan Kerapu Kertang

“…Seperti yang dilaporkan oleh beberapa peneliti bahwa dengan pemberian rGH dapat meningkatkan sintesis protein dan menurunkan sintesis lemak pada mamalia (Pell et al, 1990;Johnsson et al, 1987) dan menstimulasi anabolisme dalam meningkatkan penggantian dan sintesis protein pada ikan, yang terjadi pada hati dan otot dengan menstimulasi efisiensi dari translasi ribosom melalui peningkatan konsentrasi mRNA dan ribosom (Foster et al, 1991;Herbert et al, 2001). Mekanisme tersebut diduga melalui optimasi pemanfaatan protein sebagai sumber energi untuk pertumbuhan.…”

Recombinant bovine somatotropin increases nutrient absorption by the proximal small intestine in sheep

“…or immunization againsr SRIF (Sun et al 1990) increases digestibility of dietary nutrients. The increase in feed effi_ ciency in animals immunized against somatostatin may be due to enhanced nutrient absorption by the gut (Johnsson et al 1987;Pell et al 1990). ST is known to increase small intestinal electrolyte and fluid transport (Levin 1969;Braithwaite 1975;Mainoya 1975, tOSZ;Chipman et al 1980f and ST may regulate expression ofgenes encoding specific intestinal nutrient transporters lLobG et al.…”