Kegley E B, Harvey R W, Spears J W, Crickenberger R G
Dept. of Anim. Sci., North Carolina State University, Raleigh 27695-7621.
J Anim Sci. 1990 Feb;68(2):483-9. doi: 10.2527/1990.682483x.
Twenty-four steers initially averaging 221 kg BW were used to evaluate the effects of lysocellin and calcium (Ca) level on performance and ruminal and plasma characteristics. Lysocellin at 0 or 22 mg/kg of diet and Ca at .3 or .6% were fed in a 2 X 2 factorial arrangement of treatments. Steers in individual pens had ad libitum access to a diet consisting of 80% corn silage and 20% (DM basis) of a protein, mineral and vitamin supplement. Ruminal fluid and blood samples were collected on d 42 and 85 of the 113-d trial. Steers fed the .6% Ca diet gained faster and required less feed/unit of gain than those fed the .3% Ca diet (P less than .05). There was a tendency for a lysocellin X Ca interaction for gain and feed efficiency (P less than .10). Lysocellin tended to depress performance when fed with .3% Ca, but it tended to improve gain and feed efficiency when fed with .6% Ca. Molar proportions of propionate were higher and those of acetate were lower (P less than .01) for steers fed lysocellin. Ruminal-soluble Zn, Fe and Cu levels were higher (P less than .01) in steers fed lysocellin. Ruminal-soluble Ca (P less than .01) was higher and ruminal-soluble P and Na were lower (P less than .01) in steers fed .6% Ca. Plasma K was higher (P less than .05) in steers fed .6% Ca but it was lower (P less than .05) in steers fed lysocellin. Results of this study indicate that dietary Ca affects certain metabolic responses to lysocellin in growing cattle.
选用24头初始平均体重为221千克的阉牛，以评估溶胞菌素和钙（Ca）水平对生产性能、瘤胃及血浆特性的影响。溶胞菌素添加量为0或22毫克/千克日粮，钙添加量为0.3%或0.6%，采用2×2析因处理设计。单栏饲养的阉牛可自由采食由80%玉米青贮和20%（干物质基础）蛋白质、矿物质及维生素补充料组成的日粮。在为期113天的试验的第42天和第85天采集瘤胃液和血样。饲喂0.6%钙日粮的阉牛比饲喂0.3%钙日粮的阉牛增重更快，单位增重所需饲料更少（P<0.05）。溶胞菌素×钙对增重和饲料效率存在交互作用趋势（P<0.10）。溶胞菌素与0.3%钙一起饲喂时往往会降低生产性能，但与0.6%钙一起饲喂时往往会提高增重和饲料效率。饲喂溶胞菌素的阉牛丙酸的摩尔比例较高，乙酸的摩尔比例较低（P<0.01）。饲喂溶胞菌素的阉牛瘤胃可溶性锌、铁和铜水平较高（P<0.01）。饲喂0.6%钙的阉牛瘤胃可溶性钙较高（P<0.01），瘤胃可溶性磷和钠较低（P<0.01）。饲喂0.6%钙的阉牛血浆钾较高（P<0.05），但饲喂溶胞菌素的阉牛血浆钾较低（P<0.05）。本研究结果表明，日粮钙会影响生长牛对溶胞菌素的某些代谢反应。
