Becker Larissa L, Gebhardt Jordan T, Tokach Mike D, Arentson Roger A, Shields Michael, Woodworth Jason C, Goodband Robert D, DeRouchey Joel M, Seltzer Jenna A, Puls Christopher L
Department of Animal Sciences and Industry, College of Agriculture, Kansas State University, Manhattan, KS 66506-0201, USA.
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506-0201, USA.
Transl Anim Sci. 2024 Jun 15;8:txae099. doi: 10.1093/tas/txae099. eCollection 2024.
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 (), feed efficiency (), 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.
离子载体是一类饲料添加剂，可通过破坏细胞膜上的离子转运来减少革兰氏阳性微生物种群数量，从而提高生长性能。那拉菌素（商品名Skycis；美国礼来公司动物保健部，印第安纳州格林菲尔德）是一种经美国食品药品监督管理局批准的离子载体，用于提高生长育肥猪的增重速度和饲料效率。本研究进行了一项Meta回归分析，以评估在生长育肥猪日粮中添加那拉菌素的效果，预测其对平均日增重（ADG）、饲料效率（G:F）和胴体产量的影响。建立了一个数据库，其中包含2012年至2021年的21份技术报告、摘要和同行评议论文，代表了35项生长性能数据观察值，研究时长从35天到116天不等（总体数据）。此外，在这35项观察值中，使用每周、每两周或每月的性能间隔评估了个体阶段数据（143项观察值）（阶段数据）。建立了回归模型方程，并使用逐步手动向前选择程序评估预测变量。使用总体数据的ADG模型包括对照组的ADG、ADFI和G:F、添加的那拉菌素剂量以及分为长于或短于65天的那拉菌素饲喂持续时间。使用总体数据的G:F模型中包含的预测变量是对照组的ADG、ADFI和G:F以及添加的那拉菌素剂量。对于胴体产量，最终模型包括对照组的ADFI和G:F、添加的那拉菌素剂量以及长于65天的那拉菌素饲喂持续时间。在ADG的阶段模型中，预测变量包括对照组的ADG、ADFI和G:F、添加的那拉菌素剂量以及分为大于或小于105 kg的对照组平均体重。对于G:F的阶段数据，模型选择了对照组ADG、ADFI和G:F以及添加的那拉菌素剂量。根据结果，添加那拉菌素后ADG和G:F的总体反应呈二次曲线，并且随着ADG和G:F的增加而趋于下降。个体阶段数据也观察到类似的二次反应。总之，使用数据库中预测变量的中位数，本Meta分析表明，连续饲喂超过65天时，那拉菌素有望使ADG提高1.06%至1.65%，G:F提高0.71%至1.71%，胴体产量提高0.31%。
