Effects of lysocellin and calcium level on mineral metabolism, performance and ruminal and plasma characteristics of beef steers
Kegley, E.B. | Harvey, R.W. | Spears, J.W.
Metabolism and growth experiments were conducted to determine the effects of lysocellin and calcium level on mineral metabolism and performance of beef steers. Lysocellin at 0 or 22 mg/kg and Ca at .3 or .6% of the diet were fed in a 2 X 2 factorial arrangement of treatments. Two steers averaging 287 kg BW were fed each diet consisting of 80% corn silage and 20% supplement (DM basis) in each of two metabolism trails. Steers were fed the diets for a 21-d preliminary period, followed by 7 d of total feces and urine collection. A lysocellin X Ca interaction was observed for nitrogen retention (P < .01). Steers fed lysocellin and .6% Ca retained the most N (15.6 g/d), whereas steers receiving lysocellin and .3% Ca retained the least N (8.8 g/d). Lysocellin increased (P < .05) apparent absorption of Mg. In one of the two metabolism trials, lysocellin increased (P < .05) apparent absorption and retention of Ca. Apparent absorption and retention of Ca were higher (P < .05) in steers fed .6% Ca when expressed as grams per day, but absorption and retention were lower (P < .01) when expressed as a percentage of intake. In the other metabolism trial, the .6% Ca level decreased (P < .05) urinary P excretion and increased (P < .05) P retention as a percentage of absorbed P. In a growth experiment, 64 steers were fed similar levels of lysocellin and Ca for 119 d. Diets consisted of 90% corn silage and 10% supplement. Although no treatment effects on ADG, DMI or feed:gain were detected, lysocellin did affect concentration of several minerals in ruminal fluid and blood plasma.
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