Effects of lasalocid and monensin plus tylosin on serum metabolic hormones and clinical chemistry profiles of beef steers fed a 90% concentrate diet.
Fourteen crossbred beef steers (average initial BW 313 +/- 13.1 kg) fed a 90% concentrate diet (as-fed basis) were used to evaluate effects of ionophores on serum metabolic hormones and clinical chemistry profiles. Treatments were no ionophore (C; four steers), lasalocid (L; 33 mg/kg of diet; five steers), and monensin (33 mg/kg of diet) plus tylosin (11 mg/kg of diet; MT; five steers). All steers were adapted to the 90% concentrate diet, after which treatments were applied and blood was sampled via jugular catheters on d 7, 35, 63, 91, and 119 of the trial at 0, 1, 2, 3, 4, 6, 8, and 10 h after feeding. Averaged over sampling days, serum glucose concentrations did not differ (P > .10) among treatments at any sampling time (treatment x sampling time, P < .05). Average across sampling days and times, serum growth hormone, insulin, cholesterol, and triglyceride concentrations did not differ (P > .10) among treatments. No major effects of ionophores were noted for serum enzymes or protein fractions. Averaged over sampling times within day (treatment x day interaction, P < .10), both L and MT increased (P < .05) serum Ca and Na concentrations on d 91 and 119 compared with C. Serum inorganic P was increased (P < .10) for L vs MT and for ionophore treatments compared with C (P < .10) on several occasions (treatment x day x sampling time interaction, P < .05). Results suggest that ionophores do not cause dramatic changes in serum metabolic hormones or clinical chemistry profiles; however, monensin and lasalocid altered serum minerals in beef steers fed a high-concentrate diet.
Department of Animal and Range Sciences, New Mexico State University, Las Cruces 88003.
G C
GC
Duff
M L
ML
Galyean
M E
ME
Branine
D M
DM
Hallford
D000821:Animal Feed; D000818:Animals; D001774:Blood Chemical Analysis / Q000662:veterinary; D001786:Blood Glucose / Q000187:drug effects; D001798:Blood Proteins / Q000187:drug effects; D001806:Blood Urea Nitrogen; D002118:Calcium / Q000097:blood; D002417:Cattle / Q000097:blood*; D003404:Creatinine / Q000097:blood; D004435:Eating; D013006:Growth Hormone / Q000097:blood; D007328:Insulin / Q000097:blood; D007832:Lasalocid / Q000494:pharmacology*; D008297:Male; D008985:Monensin / Q000494:pharmacology*; D010758:Phosphorus / Q000097:blood; D011897:Random Allocation; D012964:Sodium / Q000097:blood; D015645:Tylosin / Q000494:pharmacology*; D015430:Weight Gain
D001786:Blood Glucose; D001798:Blood Proteins; D007328:Insulin; D010758:Phosphorus; D013006:Growth Hormone; D008985:Monensin; D012964:Sodium; D003404:Creatinine; D002118:Calcium; D007832:Lasalocid; D015645:Tylosin