Golder H M, Lean I J
J Anim Sci. 2016 Jan;94(1):306-26. doi: 10.2527/jas.2015-9694.
The effects of lasalocid on rumen measures, beef and dairy performance, and carcass traits were evaluated using meta-analysis. Meta-regression was used to investigate sources of heterogeneity. Ten studies (20 comparisons) were used in the meta-analysis on rumen measures. Lasalocid increased total VFA and ammonia concentrations by 6.46 and 1.44 m, respectively. Lasalocid increased propionate and decreased acetate and butyrate molar percentage (M%) by 4.62, 3.18, and 0.83%, respectively. Valerate M% and pH were not affected. Meta-regression found butyrate M% linearly increased with duration of lasalocid supplementation (DUR; = 0.017). When >200 mg/d was fed, propionate and valerate M% were higher and acetate M% was lower ( = 0.042, = 0.017, and = 0.005, respectively). Beef performance was assessed using 31 studies (67 comparisons). Lasalocid increased ADG by 40 g/d, improved feed-to-gain ratio (F:G) by 410 g/kg, and improved feed efficiency (FE; combined measure of G:F and the inverse of F:G). Lasalocid did not affect DMI, but heterogeneity in DMI was influenced by DUR ( = 0.004) and the linear effect of entry BW ( = 0.011). The combination of ≤100 vs. >100 d DUR and entry BW ≤275 vs. >275 kg showed that cattle ≤275 kg at entry fed lasalocid for >100 d had the lowest DMI. Heterogeneity of ADG was influenced by the linear effect of entry BW ( = 0.028) but not DUR. Combining entry BW ≤275 vs. >275 kg and DUR showed that cattle entering at >275 kg fed ≤100 d had the highest ADG. The FE ( = 0.025) and F:G ( = 0.015) linearly improved with dose, and entry BW >275 kg improved F:G ( = 0.038). Fourteen studies (25 comparisons) were used to assess carcass traits. Lasalocid increased HCW by 4.73 kg but not dressing percentage, mean fat cover, or marbling score. Heterogeneity of carcass traits was low and not affected by DUR or dose. Seven studies (11 comparisons) were used to assess dairy performance but the study power was relatively low and the evidence base is limited. Lasalocid decreased DMI in total mixed ration-fed cows by 0.89 kg/d but had no effect on milk yield, milk components, or component yields. Dose linearly decreased DMI ( = 0.049). The DUR did not affect heterogeneity of dairy measures. This work showed that lasalocid improved ADG, HCW, FE, and F:G for beef production. These findings may reflect improved energy efficiency from increased propionate M% and decreased acetate and butyrate M%. Large dairy studies are required for further evaluation of effects of lasalocid on dairy performance.
采用荟萃分析评估了拉沙洛西对瘤胃指标、肉牛和奶牛生产性能以及胴体性状的影响。采用元回归分析来探究异质性来源。在瘤胃指标的荟萃分析中使用了10项研究（20组比较）。拉沙洛西使总挥发性脂肪酸（VFA）和氨浓度分别增加了6.46和1.44 m。拉沙洛西使丙酸增加，乙酸和丁酸的摩尔百分比（M%）分别降低了4.62%、3.18%和0.83%。戊酸M%和pH值未受影响。元回归分析发现，丁酸M%随拉沙洛西添加持续时间（DUR）呈线性增加（= 0.017）。当饲喂量>200 mg/d时，丙酸和戊酸M%较高，乙酸M%较低（分别为 = 0.042、= 0.017和 = 0.005）。使用31项研究（67组比较）评估肉牛生产性能。拉沙洛西使平均日增重（ADG）提高了40 g/d，改善了料重比（F:G）410 g/kg，并提高了饲料效率（FE；G:F和F:G倒数的综合指标）。拉沙洛西对干物质采食量（DMI）没有影响，但DMI的异质性受DUR（= 0.004）和初始体重（entry BW）的线性效应影响（= 0.011）。DUR≤100天与>100天以及初始体重≤275 kg与>275 kg的组合表明，初始体重≤275 kg且饲喂拉沙洛西>100天的牛DMI最低。ADG的异质性受初始体重的线性效应影响（= 0.028），但不受DUR影响。将初始体重≤275 kg与>275 kg和DUR相结合表明，初始体重>275 kg且饲喂≤100天的牛ADG最高。FE（= 0.025）和F:G（= 0.015）随剂量呈线性改善，初始体重>275 kg可改善F:G（= 0.038）。使用14项研究（25组比较）评估胴体性状。拉沙洛西使热胴体重（HCW）增加了4.73 kg，但对屠宰率、平均脂肪覆盖度或大理石花纹评分没有影响。胴体性状的异质性较低，不受DUR或剂量影响。使用7项研究（11组比较）评估奶牛生产性能，但研究效能相对较低且证据基础有限。拉沙洛西使全混合日粮饲喂奶牛的DMI降低了0.89 kg/d，但对产奶量、乳成分或成分产量没有影响。剂量使DMI呈线性下降（= 0.049）。DUR不影响奶牛指标的异质性。这项研究表明，拉沙洛西可提高肉牛生产的ADG、HCW、FE和F:G。这些发现可能反映了丙酸M%增加以及乙酸和丁酸M%降低带来的能量效率提高。需要开展大型奶牛研究以进一步评估拉沙洛西对奶牛生产性能的影响。
