日粮镁水平对荷斯坦阉牛生长性能及对丙酸拉沙洛西代谢反应的影响
Influence of dietary magnesium level on growth-performance and metabolic responses of Holstein steers to laidlomycin propionate.
作者信息
Ramirez J E, Alvarez E G, Montaño M, Shen Y, Zinn R A
机构信息
Desert Research and Extension Center, University of California, El Centro 92243, USA.
出版信息
J Anim Sci. 1998 Jul;76(7):1753-9. doi: 10.2527/1998.7671753x.
We used 216 Holstein steers (151 kg) in a 262-d trial to evaluate the influence of dietary magnesium level (.19, .25, and .32%) and laidlomycin propionate (LP; 0 vs 11 ppm, air-dry basis) on growth performance and NE value of the diet. During the initial 112 d of the trial, LP increased (P < .01) ADG (6.3%) and feed efficiency (4.2%). From d 112 until slaughter, LP increased (P < .05) ADG (9.7%) and feed efficiency (4.5%). Across the 262-d feeding period, LP supplementation enhanced (P < .01) ADG (8.9%) and feed efficiency (6.3%). There was an interaction (P < .05) between dietary Mg and LP on NE value of the diet. The enhancement in NE value of the diets owing to LP with .19, .25, and .32% dietary Mg were .5, 3.0, and 5.9%, respectively. Six Holstein steers (302 kg) were used in a 6 x 6 Latin square experiment to evaluate treatment effects on characteristics of ruminal and total tract digestion. There were no treatment interactions (P > .10) on site and extent of digestion of OM, starch, and N. Supplemental Mg increased (quadratic effect, P < .10) ruminal OM digestion. Neither LP nor dietary Mg level affected (P > .10) ruminal digestion of starch and feed N. Supplemental LP decreased (15%, P < .05) ruminal microbial efficiency. Total tract digestion of OM and N increased (linear effect, P < .01) with increasing dietary Mg level. There were interactions between LP and dietary Mg level on ruminal soluble-Mg concentration (linear effect, P < .01) and Mg absorption (quadratic effect, P < .05). Apparent total tract Mg digestion increased owing to LP (P < .01) and dietary Mg level (linear effect, P < .01). There were no treatment effects (P > .10) on ruminal pH. Dietary Mg level did not influence (P > .10) ruminal VFA concentrations or molar proportions. Supplemental LP increased (14%; P < .10) total ruminal VFA concentration but did not affect (P > .10) VFA molar proportions. We conclude that LP will increase daily weight gain and feed efficiency of calf-fed Holstein steers and that this response may be enhanced by increasing dietary Mg level.
我们使用216头荷斯坦公牛（体重151千克）进行了为期262天的试验，以评估日粮镁水平（0.19%、0.25%和0.32%）和丙酸拉沙洛西（LP；风干基础下0与11 ppm）对生长性能和日粮净能值的影响。在试验的最初112天，LP提高了（P < 0.01）平均日增重（6.3%）和饲料效率（4.2%）。从第112天到屠宰，LP提高了（P < 0.05）平均日增重（9.7%）和饲料效率（4.5%）。在整个262天的饲喂期内，添加LP提高了（P < 0.01）平均日增重（8.9%）和饲料效率（6.3%）。日粮镁和LP对日粮净能值存在交互作用（P < 0.05）。日粮镁水平为0.19%、0.25%和0.32%时，LP使日粮净能值分别提高了0.5%、3.0%和5.9%。使用6头荷斯坦公牛（体重302千克）进行了6×6拉丁方试验，以评估处理对瘤胃和全消化道消化特性的影响。在有机物、淀粉和氮的消化部位和程度上，各处理间没有交互作用（P > 0.10）。添加镁提高了（二次效应，P < 0.10）瘤胃有机物消化率。LP和日粮镁水平均未影响（P > 0.10）瘤胃淀粉和饲料氮的消化。添加LP降低了（15%，P < 0.05）瘤胃微生物效率。随着日粮镁水平的提高，有机物和氮的全消化道消化率提高了（线性效应，P < 0.01）。LP和日粮镁水平对瘤胃可溶性镁浓度（线性效应，P < 0.01）和镁吸收（二次效应，P < 0.05）存在交互作用。由于LP（P < 0.01）和日粮镁水平（线性效应，P < 0.01），表观全消化道镁消化率提高。各处理对瘤胃pH没有影响（P > 0.10）。日粮镁水平未影响（P > 0.10）瘤胃挥发性脂肪酸浓度或摩尔比例。添加LP提高了（14%；P < 0.10）瘤胃挥发性脂肪酸总浓度，但未影响（P > 0.10）挥发性脂肪酸摩尔比例。我们得出结论，LP可提高犊牛饲养的荷斯坦公牛的日增重和饲料效率，并且通过提高日粮镁水平可能会增强这种反应。
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