离子载体是饲料添加剂,其通过破坏跨细胞膜的离子转移来减少革兰氏阳性微生物群体,从而导致改善的生长性能。Narasin(Skycis;Elanco动物保健,格林菲尔德,IN)是FDA批准的离子载体,用于增加生长肥育猪的增重率和改善饲料效率。进行了荟萃回归分析,以评估在生长育肥猪日粮中添加narasin的影响,以预测其对平均日增重(ADG)的影响。饲料效率(G:F),和car体产量。建立了一个包含21份技术报告的数据库,摘要,以及2012年至2021年的参考文献,代表了35项研究中对增长绩效数据的观察,研究长度为35至116d(总体数据)。此外,在这35个观察中,使用每周评估个体周期数据(143个观察值),每两周一次,或每月性能间隔(周期数据)。建立了回归模型方程,和预测变量通过逐步手动前向选择程序进行评估。使用总体数据的ADG模型包括ADG,ADFI,对照组的G:F,添加Narasin剂量,和narasin喂养持续时间分类为长于或短于65d。使用总体数据的G:F模型中包含的预测变量为ADG,ADFI,和G:对照组的F和添加的narasin剂量。对于car体产量,最终模型包括对照组的ADFI和G:F,添加Narasin剂量,和Narasin喂养持续时间超过65d。在ADG的周期模型中,预测因子包括ADG,ADFI,对照组的G:F,添加Narasin剂量,和对照组的平均BW分为大于或小于105kg。对于G:F的周期数据,选择ADG的模型,ADFI,和G:对照组的F和添加的narasin剂量。根据结果,ADG和G:F对添加narasin的总体反应是二次的,并且随着ADG和G:F的增加而趋于降低。对于各个周期数据观察到类似的二次响应。总之,使用数据库中的中值作为预测变量,这项荟萃分析表明,narasin有望将ADG提高1.06%至1.65%,G:F在0.71%和1.71%之间,连续饲喂超过65d时,car体产量降低0.31%。
Ionophores are feed additives that decrease gram-positive microbial populations by disrupting the ion transfer across cell membranes resulting in improved growth performance. Narasin (Skycis; Elanco Animal Health, Greenfield, IN) is an FDA-approved
ionophore utilized for increased rate of weight gain and improved feed efficiency in growing-finishing pigs. A meta-regression analysis was conducted to evaluate the effects of added narasin in growing-finishing pig diets to predict its influence on average daily gain (ADG), feed efficiency (G:F), and carcass yield. A database was developed containing 21 technical reports, abstracts, and refereed papers from 2012 to 2021 representing 35 observations for growth performance data in studies ranging from 35 to 116 d in length (overall data). In addition, within these 35 observations, individual period data were evaluated (143 observations) using weekly, bi-weekly, or monthly performance intervals (period data). Regression model equations were developed, and predictor variables were assessed with a stepwise manual forward selection procedure. The ADG model using the overall data included ADG, ADFI, and G:F of the control group, added narasin dose, and narasin feeding duration categorized as longer or shorter than 65 d. Predictor variables included in the G:F model using overall data were ADG, ADFI, and G:F of the control group and added narasin dose. For carcass yield, the final model included ADFI and G:F of the control group, added narasin dose, and narasin feeding duration of longer than 65 d. In the period model for ADG, the predictors included ADG, ADFI, and G:F of the control group, added narasin dose, and average BW of the control group categorized into greater than or less than 105 kg. For period data for G:F, the model selected ADG, ADFI, and G:F of the control group and added narasin dose. Based on the results, the overall response to added narasin for ADG and G:F was quadratic and tended to decrease as ADG and G:F increased. A similar quadratic response was observed for the individual period data. In summary, using median values from the database for predictor variables, this meta-analysis demonstrated narasin would be expected to improve ADG between 1.06% and 1.65%, G:F between 0.71% and 1.71%, and carcass yield by 0.31% when fed continuously for longer than 65 d.