Enhancing digestion efficiency and weaning success of dairy calves through provision of a novel calf starter

向产奶犊牛提供更多的牛奶已被证明可以改善短期和长期犊牛的性能和效率以及整体福利。喂养更高水平的牛奶的一个挑战是成功地断奶。由于小牛对牛奶有天然的偏好，当在两者之间进行选择时，它们倾向于消耗牛奶而不是固体饲料。因此，饲喂较高水平的牛奶可以减少断奶前小牛消耗的固体饲料量。断奶奶犊牛断乳是一个紧张的过渡，可能对犊牛的生理和行为产生不利影响。为了帮助缓解断奶压力，重要的是小牛在去除牛奶之前消耗足够量的固体饲料，以使小牛在此饮食过渡期间发育其瘤胃并保持其健康和性能。这需要一个适当的断奶方案，以及在此期间喂养高度可口和易消化的饲料。因此，本项目的目的是确定饲喂一种新的、基于乳副产品（乳清）的犊牛料对犊牛生长、效率和福利的影响。将进行一项随机研究，以检验以下假设：与仅饲喂传统谷物型犊牛料的犊牛相比，饲喂基于乳副产品的犊牛料的犊牛料将在生命早期开始食用固体饲料，经历更快的瘤胃发育，并显示出更高的断奶后消化效率。这样的研究对于专门从事动物营养和饲料产品以支持动物性能的Grand Valley Fortifiers非常重要。对于Grand Valley Fortifiers来说，调查这种新型饲料产品效果的可靠科学研究至关重要，以便能够自信地向客户提供如何在生命早期最好地喂养小牛的建议。这项研究也将补充圭尔夫大学的研究，发现影响小牛断奶后改用固体饲料时发生的生理变化的因素。具体来说，这项研究将提供一种潜在的新饲料的新见解，以提供小牛，以鼓励饲料摄入量和方便断奶成功。这项研究的主要受益者是加拿大的乳制品生产商，他们可以利用这种饲料来优化他们的奶牛的生长，健康和福利。

Provision of higher quantities of milk to dairy calves has been shown to improve short- and long-term calf performance and efficiency, and overall welfare. A challenge with feeding higher levels of milk is the successful weaning off that milk. With calves having a natural preference for milk, they will tend to consume milk over solid feed when given the choice between the two. Therefore, feeding higher levels of milk can decrease the amount of solid feed calves consume prior to weaning. Weaning dairy calves off milk is a stressful transition and can have detrimental effects on calf physiology and behaviour. To help ease weaning stress, it is important that calves consume sufficient amounts of solid feed, prior to the removal of milk, for calves to develop their rumen and maintain their health and performance during this dietary transition. This requires a proper weaning protocol as well as the feeding of both a highly palatable and digestible feed during this time period. Thus, the objective of this project is to determine the impact of feeding a novel, milk by-product (whey) based calf starter on the growth, efficiency, and welfare of calves. A randomized study will be conducted to test the hypothesis that calves fed a milk by-product based calf starter will start to consume solid feed earlier in life, experience faster rumen development, and show greater efficiency of digestion post-weaning than calves fed only a traditional grain-based calf starter. Such research is important to Grand Valley Fortifiers, who specialize in animal nutrition, and feed products to support animal performance. Sound scientific research investigating the effects of this novel feed product is essential for Grand Valley Fortifiers to be able confidently advise their clientele on how best to feed calves early in life. This research will also complement research at the University of Guelph in discovering factors influencing physiological changes that occur as calves wean off milk onto solid feed. Specifically, this research will provide novel insight on a potential new feed to offer calves to encourage feed intake and ease weaning success. The primary beneficiaries of this research are the Canadian dairy producers who can utilize this feed to optimize growth, health, and welfare of their dairy calves.