摘要
Our objective was to determine the effects of dry and wet conditions during the preweaning on subsequent feedlot performance and carcass characteristics of beef cattle. Steers (n = 7,432) and heifers (n = 2,361) finished in 16 feedlots in southwestern Iowa through the Tri-County Steer Carcass Futurity Cooperative were used for a retrospective analysis. Cattle originated in the Midwest (Iowa, Missouri, Indiana, Illinois, and Minnesota) and were born in February, March, or April of 2002 through 2013. Feedlot performance and carcass composition data were obtained for each animal. Palmer Drought Severity Index (PDSI) values were obtained for each animal’s preweaning environment on a monthly basis. Mean PDSI values were used to classify conditions as dry (≤−2.0), normal (>−2.0 and <2.0), or wet (≥2.0) for the cool (April and May), warm (June through August), and combined (April through August) forage growing seasons preweaning. Mixed models were used to evaluate the effects of PDSI class on subsequent performance. Calf sex, date of birth (as day of year), year, and feedlot were also included as fixed effects. When considering PDSI class during the cool season, cattle from normal and wet classes had a greater feedlot delivery BW (P < 0.0001) than dry. Dry and normal classes had greater (P ≤ 0.02) delivery BW than wet during the warm and combined seasons, however. For the cool season, average daily gain was greater (P < 0.0001) for the dry class than normal and wet. Cattle from the normal class for the cool season had greater (P = 0.001) final BW than wet, but the wet class had the greatest (P < 0.04) and dry class had the lowest (P < 0.01) final BW during the warm season. During the cool season, HCW was greater (P < 0.007) for the normal than wet class, although HCW was greater (P ≤ 0.02) for wet compared with dry and normal during the warm season. Calculated yield grade was lower (P ≤ 0.006) for the normal class during the cool season compared with dry and wet. For both the warm and combined seasons, the dry class had lower (P ≤ 0.004) calculated yield grade compared with normal and wet. Carcasses from cattle that experienced normal or wet warm seasons had greater (P ≤ 0.0005) marbling scores than dry, and normal had greater (P = 0.0009) marbling score than dry for the combined seasons. In conclusion, these data indicate that both dry and wet conditions during the preweaning phase may impact ultimate feedlot performance and carcass composition.
摘要译文
我们的目标是确定断奶前干燥和潮湿条件对肉牛后续饲养场性能和胴体特性的影响。通过Tri-County Steer Carcass Futurity Cooperative在爱荷华州西南部的16个饲养场中完成的阉牛（n = 7,432）和小母牛（n = 2,361）用于回顾性分析。牛起源于中西部（爱荷华州，密苏里州，印第安纳州，伊利诺伊州和明尼苏达州），出生于2002年2月，3月或4月至2013年。获得每只动物的饲养场性能和胴体组成数据。每月为每只动物的断奶前环境获得帕尔默干旱严重程度指数（PDSI）值。平均PDSI值用于将冷却（4月和5月），温暖（6月至8月）的干燥（≤-2.0），正常（> -2.0和<2.0）或湿润（≥2.0）的条件分类，并合并（4月至8月）饲料生长季节断奶。混合模型用于评估PDSI类对后续性能的影响。小牛性别，出生日期（一年中的一天），年份和饲养场也包括在内作为固定效应。在凉爽季节考虑PDSI分类时，正常和湿润类型的牛的饲养场输送BW（P <0.0001）大于干燥。然而，干燥和正常类别在温暖和结合的季节中具有比湿润更大（P≤0.02）的递送BW。对于凉爽的季节，干燥阶段的平均日增重（P <0.0001）比正常和湿润更大（P <0.0001）。凉季正常类别的牛最终BW比湿润的最大（P = 0.001），但湿水类最高（P <0.04），干燥类在温暖季节的最终BW最低（P <0.01） 。在凉爽的季节，HCW比正常湿度更高（P <0.007），尽管在暖季期间HCW比干燥和正常湿度更大（P≤0.02）。与干燥和潮湿相比，冷季期间正常类别的计算产量等级较低（P≤0.006）。对于温暖和复合季节，干燥等级与正常和湿润相比具有较低的（P≤0.004）计算的产量等级。来自正常或潮湿的温暖季节的牛的尸体具有比干燥更大的（P≤0.0005）大理石花纹分数，并且在合并季节中正常具有比干燥大的（P = 0.0009）大理石花纹分数。总之，这些数据表明在断奶前阶段的干燥和潮湿条件都可能影响最终饲养场性能和胴体组成。
Garth A Gatson[1];Patrick J Gunn[2];W Darrell Busby[3];Bryon R Wiegand[1];Brian L Vander Ley[4];Allison M Meyer[1]. Effects of dry or wet conditions during the preweaning phase on subsequent feedlot performance and carcass composition of beef cattle[J]. Translational Animal Science, 2019,3(1): 247-255