摘要
The objective of the present study was to evaluate the effect of nutritional management treatments during the rearing period on the performance and carcass traits of Hereford steers finished either on pasture or in feedlot. Two hundred and forty male Hereford calves, weaned at 8 months of age with an average weight of 170 ± 17 kg, were used. After weaning, four nutritional treatments were imposed on the calves so as to obtain different daily liveweight gains (LWGs, kg/day) during the first winter (winter-growth phase). The nutritional management groups were high LWG in feedlot (HF), low LWG in feedlot (LF), high LWG on pasture (HP) and low LWG on pasture (LP). Finishing phase began when each group reached a mean liveweight (LW) of 350 ± 28 kg. During this phase, one half of the HF, LF, HP and LP animals were finished on pasture and the other half in feedlot. The animals were slaughtered when each group attained a mean LW of 500 kg. The carcass traits ribeye area (cm2) and backfat thickness (mm) were measured by ultrasonography. Liveweight, LWG and ultrasonography records were analysed by repeated-measures analysis. DM intake as a percentage of LW and feed conversion ratio (FCR; kg DM/kg LW) during feedlot were analysed by ANOVA. Least-square means for LWGs of pasture-finished animals were 0.807, 0.799, 0.819c and 0.782 kg/day for HF, LF, HP and LP respectively. Least-square means for LWG of feedlot-finished animals were 1.569, 1.554, 1.484 and 1.431 kg/day for HF, LF, HP and LP respectively. Least-square means for FCR in feedlot were 7.12, 7.20, 7.97 and 8.92 for HF, LF, HP and LP respectively. Hot carcass weight had a similar trend as did LWG. Feedlot-finished animals attained heavier hot carcass weights once they received a better nutritional management during the first winter. The growth-group management did not affect (P > 0.05) dressing percentage. The carcasses of feedlot-finished animals showed higher (P < 0.05) dressing percentages than did carcasses of pasture-finished animals. Nutritional feeding management during the first winter had permanent effects on growth, carcass and FCR traits; however, the prevalence of these effects depended on the feeding system during the finishing phase. On the basis of the results obtained in the study, it is recommended that animals receive an adequate nutritional management during the first winter so as to maximise their future performance, especially for intensive beef-cattle growing–finishing systems. However, if the animals have been subjected to restriction during early growth, they should be finished under pasture conditions.
摘要译文
本研究的目的是评估营养管理治疗在饲养期间的营养管理治疗对牧草的性能和胴体特征在牧场或饲料中的表现。二百四十个男性贝尔斯犊牛，在8个月的年龄断奶，平均重量为170±17千克。断奶后，在犊牛上施加了四个营养处理，以便在第一个冬季（冬季生长阶段）中获得不同的日常活重增益（LWGS，KG /天）。营养管理基团在饲料（HF）中的高LWG，饲料（LF）低LWG，牧场（HP）上的高LWG和牧场上的低LWG（LP）。完成阶段开始，当每组达到350±28公斤的平均活力（LW）时开始。在此阶段，HF，LF，HP和LP动物的一半在牧场和其他一半的饲料中完成。当每组达到500千克的平均值时，动物被屠宰。通过超声检查测量胎体性状ribeye区域（CM2）和背脂厚度（mm）。通过重复措施分析分析了LiveVeight，LWG和超声检查记录。 DM摄入量为LW和饲料转换率的百分比（FCR;通过ANOVA分析饲料期间的Kg DM / kg LW。对于HF，LF，HP和LP，LWG的牧场成品LWG的最小方形是0.807,0.799,0.819℃和0.782kg /天。对于HF，LF，HP和LP，饲养物完成的动物LWG的最小二乘法分别为1.569,1.554,1.484和1.431千克/天。用于HF，LF，HP和LP的饲料中FCR中FCR的最小二乘法分别为7.12,7.20,7.97和8.92。热胴体重量与LWG有类似的趋势。一旦他们在第一次冬天获得了更好的营养管理，饲养就成品的动物率达到较重的热胴体重量。生长组管理不影响（P> 0.05）敷料百分比。饲养的动物的尸体显示出更高（P <0.05）的敷料比牧场成品的尸体百分比。第一冬季期间的营养饲养管理对生长，胴体和FCR特征有永久性影响;然而，这些效果的患病率依赖于在整理阶段期间的饲养系统。在研究中获得的结果，建议动物在第一个冬季获得足够的营养管理，以最大限度地提高其未来的性能，特别是对于强化牛肉生长整理系统。但是，如果动物在早期生长期间受到限制，则应在牧场条件下完成。
Elisa Peripolli [A] [D];Georgget Banchero [B];Angélica Simone Cravo Pereira [C];Gustavo Brito [B];Alejandro La Manna [B];Enrique Fernandez [B];Fabio Montossi [B];Fernando Baldi [A]. Effect of growth path on the performance and carcass traits of Hereford steers finished either on pasture or in feedlot[J]. Animal Production Science, 2018,58(7): 1341-1348