title: Interactive effects among porcine somatotropin, the beta-adrenergic agonist salbutamol, and dietary lysine on growth performance and nitrogen balance of finishing swine.
abstract: An experiment was conducted to evaluate the interactive effects among porcine somatotropin (pST), salbutamol, and dietary lysine on growth performance, nitrogen balance, and carcass characteristics of finishing barrows (n = 32; 62.8 kg initially). Two replicate 32-d studies were set up in a split-plot design to evaluate singular and combined use of pST (0 or 4 mg/d) and salbutamol (0 or 2.75 ppm of the diet) as whole-plot treatments and diets containing .8, 1.2, 1.6, or 2.0% lysine as subplot treatments. Dietary lysine levels were administered within subplots in a 4 x 4 Latin square with pigs allowed 4 d of adjustment to diets followed by 4 d of urine and feces collection for determination of N retention and apparent digestibility of DM and N. Interactions between lysine and salbutamol were not found (P > .16). A pST x lysine interaction (P < .05) resulted in ADG being maximized at 1.2% lysine for pST-treated pigs (lysine quadratic, P < .02) but decreased linearly (P < .02) with increasing lysine for pigs receiving buffer. Pigs injected with 4 mg/d of pST had improved gain:feed (G:F) up to 1.2% lysine (lysine quadratic, P < .05), but no further increase to 2% lysine, whereas pigs injected with buffer showed no benefit from increased lysine (pST x lysine, P < .06). Pigs receiving buffer had greater increases in plasma urea N (PUN) as lysine increased than those receiving pST (pST x lysine, P < .002), but PUN was reduced by pST (P < .001) regardless of lysine level.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-0201.
authors.forename: J A
authors.initials: JA
authors.lastname: Hansen
authors.forename: J L
authors.initials: JL
authors.lastname: Nelssen
authors.forename: R D
authors.initials: RD
authors.lastname: Goodband
authors.forename: J L
authors.initials: JL
authors.lastname: Laurin
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects / Q000254:growth & development; D000420:Albuterol / Q000494:pharmacology*; D000818:Animals; D001806:Blood Urea Nitrogen; D004032:Diet; D004043:Dietary Fiber; D004063:Digestion / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D013006:Growth Hormone / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects / Q000254:growth & development; D008099:Liver / Q000187:drug effects / Q000254:growth & development; D008239:Lysine / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008460:Meat / Q000592:standards; D024510:Muscle Development; D009132:Muscles / Q000187:drug effects; D009584:Nitrogen / Q000378:metabolism*; D009929:Organ Size / Q000187:drug effects; D011994:Recombinant Proteins / Q000494:pharmacology; D013552:Swine / Q000254:growth & development* / Q000378:metabolism; D015430:Weight Gain / Q000187:drug effects
chemical_list: D004043:Dietary Fiber; D011994:Recombinant Proteins; D013006:Growth Hormone; D008239:Lysine; D009584:Nitrogen; D000420:Albuterol