Porcine somatotropin and dietary lysine influence bone mineralization and mechanical properties of bones in finishing swine.
The femur, a rib, and a third metacarpal were collected from 108 barrows (initial weight = 57 kg) and analyzed to determine the effects of porcine somatotropin (pST) and dietary lysine on bone mineralization and mechanical properties. In Exp. 1, pigs were injected daily with 4 mg of pST and fed diets containing 1.0% Ca and .9% P and either .6, .8, 1.0, 1.2, or 1.4% lysine. Control pigs (placebo injection) received the .6% lysine diet. Bone wall thickness (BWT) of the femur increased (linear, P < .05) but ash content decreased (linear, P < .10) as dietary lysine level increased. Stress and ash content of the rib also decreased (linear, P < .05) with increasing dietary lysine level. In Exp. 2, pigs were injected with either 4 or 8 mg/d of pST and fed diets containing 1.1% Ca and 1.0% P and either .8, 1.0, 1.2, or 1.4% lysine. Control pigs received the .8% lysine diet. Increasing pST dosage increased BWT of the femur (linear, P < .10) but decreased ash content (linear, P < .10). In the rib, increasing pST dosage reduced stress, modulus of elasticity (linear, P < .10), and ash content (linear, P < .01). Increasing lysine level resulted in increased BWT of the femur and decreased ash content of rib, femur, and metacarpal (linear, P < .10). These data indicate that pST administration in conjunction with increasing lysine levels decreases bone ash content but increases BWT of finishing pigs.
Goodband
R D
RD
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-0201.
Hines
R H
RH
Nelssen
J L
JL
Kropf
D H
DH
Schricker
B R
BR
D000469:Alkaline Phosphatase / Q000097:blood; D000821:Animal Feed; D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D001842:Bone and Bones / Q000187:drug effects* / Q000502:physiology; D005269:Femur / Q000187:drug effects / Q000502:physiology; D013006:Growth Hormone / Q000494:pharmacology*; D008239:Lysine / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008663:Metacarpus / Q000187:drug effects / Q000502:physiology; D011897:Random Allocation; D012272:Ribs / Q000187:drug effects / Q000502:physiology; D013552:Swine / Q000502:physiology*
D013006:Growth Hormone; D000469:Alkaline Phosphatase; D008239:Lysine