It is common practice for stocker cattle producers to purchase cattle from sale barns at weaning in the fall, receive and precondition them in drylot environments for approximately 45 days, then grow them out on wheat pasture before sending them to feedyards for fattening prior to final processing. Past research suggests cattle transitioning to wheat pasture from a drylot require an acclimation period before they gain significant body weight. In fact, it has been shown that substantial weight loss often occurs during the drylot-to-pasture adaptation period. Previous research also concludes that weight loss can be decreased by altering the diet in the drylot prior to turning cattle out to wheat pasture. With this finding in mind, it has been hypothesized that providing a transitional diet during the drylot phase and during the first three weeks of wheat pasture can significantly reduce weight loss during the adaptation period.
要探索这一主题，我们开展了一个有两个目标的项目：
- 确定过渡饮食策略对放牧期间的储料器小河平均每日收益和总增益的影响。
- 确定过渡饮食策略是否比传统实践更有利可图。
数据和方法
我们在这项实验中使用了307家Stocker Heifers，所有这些都在2015年至2015年秋季开始从俄克拉荷马州的农场和牧场购买，抵达贵宾研究所设施时，所有的小母牛都收到了同样的预处理治疗。188bet金宝搏代理所有小母牛均已用标准接收协议治疗。鉴于婴儿疫苗和零醇植入物，在奥克拉荷马州爱县的奥斯沃尔牧场牛处理设施抵达时，对患有梭疫苗和零醇植入的内部寄生虫进行治疗。
Heifers were randomly assigned to one of six 6-acre preconditioning pastures (two pastures per treatment), stratified by weight. The average starting weight of the heifers in each treatment group was 524 pounds. We used 120 head in 2015 (body weight ± standard deviation = 456 ± 3.94 pounds), 92 head in 2016 (531 ± 8.20 pounds) and 95 head in 2017 (584 ± 8.49 pounds).
每年将三种替代饮食治疗随机分配给动物：
- 低能量饮食仅在旱地阶段喂食1％的动物体重（1％BWDL.）。
- 高能量饮食仅在旱地阶段喂食2％的动物体重（2%BWDL）。
- 高能量饮食在旱地阶段和小麦牧场阶段的前21天内以2％的动物体重喂食（2%BWDL）。
这1％BWDL.代表在预处理阶段喂食到储存器牛的典型（对照）饮食。所有三种饮食都有相同的成分。2015年，2016年和2017年的小学队员分别为84,39和44天的Drylot。由于落下的干旱，2015年司机的天数大得多。每天早上每天早上一次记录斜槽重量，每个动物在司徒阶段的开始和结束时为每只动物进行一次。一旦完成了最终阶段称重，牛在同一天运输到贵贵的红河牧场，随机分配到六个小麦饲料牧场之一。每个牧场的牛在三个GrowSafe牛肉®个体动物称重尺度中获得水。在放牧期的持续时间内记录单个动物每日重量。
我们使用了差异的混合效应分析（Anova.）模型，以测试在旱味和小麦牧场在放牧阶段的三种替代饮食之间平均每日收益和总增益的统计差异的假设。我们还使用了对比测试来测试在第1天，第7天，第14天和在放牧期间和放牧期间的三个饮食治疗之间的牧场放牧阶段累积总重量增长的假设。平均而言，这是第119天。这很重要，因为之前的文献表明，旱地和牧场之间的适应时间通常在前两周内发生。
企业预算技术以及从混合中获得的参数估计一起使用Anova.models described above to determine the effect of each diet treatment on the profitability of a typical stocker cattle production system.
表1.饮食策略的收入，成本和净返回的培训班大学绩效和预期价值的三年平均措施
饮食治疗*
| 动物和经济表现的措施： | 仅限能量毒滴（1％BWDL） | 仅高能毒细胞（2％BWDL） | 过渡性旱田和小麦牧场（2％BWDLWP） | p值 |
|---|---|---|---|---|
| 德伦阶段 | ||||
| Beginning date | 10月10日 | 10月10日 | 10月10日 | - |
| 开始重量（每头磅） | 524. | 524. | 524. | 0.9214 |
| 在旱滴水（天）饲料的日子 | 56. | 56. | 56. | - |
| 平均每日收益（每头磅） | 1.46一种 | 1.90B. | 1.90B. | 0.0325. |
| 总增益（每头磅） | 81.76一种 | 106.40B. | 106.40B. | 0.0255. |
| 在旱滴角中重量（每头磅） | 605.76一种 | 630.40B. | 630.40B. | 0.0365 |
| 小麦牧场阶段 | ||||
| 安置日期 | 12月5日 | 12月5日 | 12月5日 | - |
| 库存率（每英亩头部） | 1.50 | 1.50 | 1.50 | - |
| 放牧持续时间（天） | 119. | 119. | 119. | - |
| 第1天总累计增益（每头省磅） | -28.38一种 | -20.09.B. | -21.83C | 0.0214 |
| Total accumulated gain on Day 7 (pounds per head) | -16.78一种 | -14.12B. | -8.56C | 0.0354 |
| Total accumulated gain on Day 14 (pounds per head) | 2.54一种 | 3.15一种 | 11.33B. | 0.0145. |
| 第119天总累计增益（每头磅） | 256.46 | 258.36 | 242.06 | 0.1254 |
| 放牧终止日期 | 4月3日 | 4月3日 | 4月3日 | - |
| 最终体重（每头磅） | 862.22 | 888.76. | 872.46 | 0.1254 |
| 平均每日收益（每头磅） | 2.18 | 2.18 | 2.05 | 0.1963 |
| 经济学 | ||||
| 旱地和小麦牧场的总增益（每头磅） | 338.22 | 364.76 | 348.46 | 0.1689 |
| 十年平均收益价值（每磅成本） | 0.90 | 0.90 | 0.90 | - |
| 收入（每头部成本） | 328.28 | 328.28 | 328.28 | - |
| Preconditioning costs, excluding feed (cost per head) | 39.50. | 39.50. | 39.50. | - |
| 种子和种子建立成本（每头部成本） | 55.77 | 57.77 | 55.77 | - |
| 肥料和肥料应用成本（每头部成本） | 45.36 | 45.36 | 45.36 | - |
| 杀虫剂和农药应用成本（每头脑成本） | 18.00 | 18.00 | 18.00 | - |
| 饲料成本（每头部成本） | 47.79 | 98.05 | 134.3. | - |
| 现金运营费用的利息成本（每头脑成本） | 2.72 | 3.41 | 3.86 | - |
| Stocker Heifer所有权的利息成本（每头脑成本） | 20.04 | 20.04 | 20.04 | - |
| 总成本（每头部成本） | 229.17 | 282.12 | 316.82 | - |
| Net return (cost per head) | 99.11 | 46.16 | 11.46 | - |
| 净返回的相对差异（每头部成本） | - | -52.95 | -87.65 | - |
| 相对融合的饲料成本（每头部成本） | - | 45.10 | 46.65 | - |
*行中不同的信件在统计上不同，信心95％。
结果
动物性能
Three-year average measures of stocker cattle heifer performance and expected values for revenues, costs and net returns by diet strategy are reported in Table 1.
小麦放牧阶段的三年平均每日增益为2.18,2.18和2.05英镑，每头为1％BWDL.那2%BWDL和2%BWDL节食分别;它们没有统计学不同，信心95％。
全部三年的第1天结束时的总累积重量增益为-28.4，-20.1和-21.8磅/磅1％BWDL.那2%BWDL和2%BWDL节食分别。这三重重量均有统计学不同，彼此有95％的信心水平，并且与以前的研究结果类似。
在一周（第7天）后，所有三种饮食中累积的增益仍然是阴性，但与第1天相比，基本上不那么负。到第二周（第7天）结束时，所有三个治疗的总累积体重增加为2.5每头部3.2和11.3磅1％BWDL.那2%BWDL和2%BWDL节食分别。
第14天权重1％BWDL.和2%BWDL饮食在统计学上没有不同，但既小于2%BWDL权重95％的自信。该结果表明过渡饮食（2%BWDL）在第1天的速度比其他两种饮食更快地改善重量损失。不幸的是，这种差异在小麦牧场放牧期结束时没有阻碍。
在该期间结束时，总累计重量增益为257,259和242磅/磅1％BWDL.那2%BWDL和2%BWDL饮食分别彼此没有统计学不同，信心95％。
经济学
Because the total accumulated gain from both the drylot and the wheat pasture phases between the three diets were not statistically different (P = 0.1689), revenues from the three diets are the same. We calculated revenue for each diet strategy using total gains from the2%BWDL饮食（即每头部364.76磅）和10年（2010-2020）平均价值为每磅0.90美元。这是一个任意选择，给了我们三个收益之间最大的收入。我们可以轻松选择使用来自的增益1％BWDL.(control) diet, which would have given all three systems the smallest revenue. We also included the total list of costs associated with our stocker system, including preconditioning/healthcare, seed and seed establishment, fertilizer and fertilizer application, pest management, feed, and interest on cash operating capital and cash operating capital for purchased stocker cattle. However, you can see from a glance at Table 1 that the only costs that vary between the three diet strategies is the cost of feed and the portion of the interest for operating capital associated with feed. As a result, net return for the2%BWDL和2%BWDL饮食比低于52.95和87.651％BWDL.（控制）饮食策略。
结论
混合的结果Anova.models, as they pertain to the weight gain of cattle in these two feeding segments, concur with and confirm much of what has already been established by previous research on cattle adapting to wheat pasture. During the drylot phase, cattle that are fed more can be expected to gain more weight. During the pasture phase, weight loss that cattle may experience is expected to occur almost immediately after turnout as they transition to pasture. Because of the individual animal data obtained from the Growsafe Beef units, we were able to show that positive daily gains begin as soon as the third day after transitioning rather than slowly over time as the literature suggests. Although previous work has attributed the change in weight to what is often referred to as a two-week adaptation or transition period, the results of this study indicate that the transition period is much shorter. This information is valuable because it shows producers that the net losses from this adaptation period are relatively small.
Although providing a high-energy supplement to cattle transitioning to pasture affected their weight gain during the first two weeks, the gains were not sustained in the long run. The additional cost of feed in drylot and on pasture were the determining factors for the economics. The most economically sound practice is to not provide any energy supplement with the intent of aiding cattle transitioning to wheat pasture. Hence, we do not recommend providing energy supplementation to aid cattle in adapting to wheat pasture.
