摘要
Corn silage is the predominant mechanically harvested forage source for feedlot cattle production in the United States because of high yield. Alternatively, because of multiple cuttings per year and lower annual cost, the use of alfalfa or other forages, may increase opportunities for manure spreading, perennial soil cover, pollinator habitat, and greater carbon sequestration. The objective of this trial was to determine the feeding value of alfalfa haylage when replacing corn silage in growing cattle diets. One-hundred-sixty-five Angus crossbred steers [326 ± 51 kg of body weight (BW)] were blocked by initial BW and randomly assigned to one of 28 pens at the University of Minnesota feedlot. Pens were randomly assigned to dietary growing treatments. The control diet was comprised of (DM basis) 50% corn silage, 19.25% rolled corn grain, 19.25% high moisture corn, 7% dried distillers grains plus solubles, and 4.5% liquid supplement (corn silage control, CS Control). For alfalfa haylage (AH) diets, AH substituted corn silage at 33% (AH 33), 66% (AH 66), or 100% (AH 100). Growth performance measurements [dry matter intake (DMI), average daily gain (ADG) and gain to feed (G:F) ratio] were assessed for 42 to 70 d depending on BW block. Afterwards, steers were fed a common finishing diet until harvested. There was a linear increase in DMI (P P ≤ 0.05) ADG and G:F. No differences (P ≥ 0.10) were observed in finishing performance or carcass traits. Results from this study demonstrated that greater substitution of corn silage with alfalfa haylage in growing diets resulted in greater intake but reduced rate of gain and gain:feed. Despite slower rate of gain, cattle fed alfalfa haylage at increasing proportions during the growing period were able to compensate in BW gains during the finishing period and reached harvest weight and backfat thickness at similar days on feed than those fed corn silage. Based on these results the energy value of corn silage and alfalfa haylage were 3.05 and 2.39 Mcal ME/kg of DM, respectively, when included at 50% of the diet DM.
摘要译文
由于高产量，玉米青贮饲料是美国饲养牛生产的主要机械收获的草料来源。另外，由于每年多次插条和较低的年成本，使用苜蓿或其他草料，可能会增加肥料扩散的机会，多年生土壤覆盖，传粉媒介栖息地和更大的碳固执。该试验的目的是确定在替代种植牛饮食中的玉米青贮饲料时，苜蓿干草的饲料值。一百六十五个Angus杂交转向[326±51 kg体重（BW）]被初始BW阻塞，并随机分配给明尼苏达大学饲养场的28支笔之一。笔随机分配给饮食生长的治疗方法。对照饮食由（DM基础）50％玉米青贮饲料，19.25％卷玉米颗粒，19.25％的高水分玉米，7％的干蒸馏剂颗粒加上溶解性，以及4.5％的液体补充剂（玉米青贮饲料，CS Control）。对于苜蓿干草（AH）饮食，AH以33％（AH 33），66％（AH 66）或100％（AH 100）代替玉米青贮饲料。根据BW块，评估了42至70 d的增长绩效测量[干物质摄入量（DMI），平均每日增益（ADG）和进食（G：F）比率42至70 d。之后，牛奶被喂食常见的饮食，直到收获为止。DMI（p≤0.05）ADG和G：f线性增加。在完成性能或car体性状方面未观察到差异（p≥0.10）。这项研究的结果表明，在不断增长的饮食中，更大的玉米青贮饲料替代玉米青贮饲料会导致更大的摄入量，但增益率降低了：饲料。尽管增益速度较慢，但在生长期间以增加比例的牛喂养的牛在整理期内能够补偿BW的增长，并且在饲料时类似的天数在相似的天数中达到了收获的重量和回脂，而不是那些喂食玉米灰烬。基于这些结果，玉米青贮饲料和苜蓿干草的能量值分别为DM的MCAL ME/KG，分别为DM的50％。
Federico Tarnonsky [1]; Katherine Hochmuth [2]; Alfredo DiCostanzo [3]; Nicolas DiLorenzo [1]. Effects of replacing corn silage with alfalfa haylage in growing beef cattle diets on performance during the growing and finishing period[J]. Journal of Animal Science, 2023,101