Influence of dietary calcium on feedlot performance of steers
Burghardi, S.R.; Goodrich, R.D.; Meiske, J.C.; Windels, H.F.
Nutrition Reports International 37(6): 1199-1214
1988
ISSN/ISBN: 0029-6635
Accession: 001862560
Five trials were conducted to examine effects of dietary Ca on feedlot performance and digestibility. Dietary treatments in Trial 1 were .3, .4, .5 or .6% Ca with supplemental Ca supplied as ground limestone (CaCO3). Level of Ca did not affect feedlot performance of fecal measurements during the growing phase (high forage). Finishing phase (high grain) daily gains and carcass marbling scores, fat depth and quality grades responded linearly (p < .01, .01, .05 and .01, respectively) to dietary Ca. Fecal pH appeared to increase with increasing dietary Ca. Corn silage treatments in Trial 2 were control, CaCO3-treated (1.0%, wet basis), formic acid-treated (.5%, wet basis) and control with CaCO3 added at feeding to equal Ca provided by CaCO3-treated corn silage. Feedlot performance and apparent digestibilities of dry matter (DM), organic matter (OM) and starch were not improved by silage treatments. Treatment in Trial 3 included .32 or .60% Ca as CaCO3 fed with corn particle sizes of 2561 (cracked) or 6110 .mu.m (whole) in a factorial arrangement of treatments. Dietary Ca did not influence feedlot performance. Steers fed whole corn gained faster (P < .05) than those fed cracked corn. Treatments in Trial 4 were .3, .5, .7 or .9% Ca as CaCO3. Level of Ca did not influence feedlot performance during the growing or finishing phases. Kidney, heart and pelvic fat and fat thickness responded linearly to dietary Ca (P <. 05). Fecal pH appeared to increase with increasing dietary Ca. Dietary treatment in Trial 5 were ground barley or ground corn fed with .3 or .6% Ca. In the growing phase, feedlot performance and fecal characteristics were not influenced by dietary Ca or grain source. Finishing phase daily gains were not improved by increased dietary Ca. Steers fed barley diets gained faster (P < .05) than steers fed corn grain. Rib eye area was greater (P < .05) in steers fed barley diets gained faster (P < .05) than steers fed barley than in those fed corn diets. Dietary Ca did not influence carcass characteristics.