Feeding strategies favoring dam and calf health and performance: a winning combination for dairy farms

相对于分娩，从-3至3周的过渡期对于现代奶牛来说是具有挑战性的，因为可能会发生一些健康问题。例如，产犊前饮食不足会加剧哺乳早期的负能量平衡状态，然后有利于过度的身体储备动员，导致代谢疾病。小牛出生时就有一个无功能的免疫系统，它们依赖于初乳的消耗来获得免疫球蛋白来对抗潜在的感染因子。奶牛和小牛的早期泌乳和早期生命问题分别给乳制品生产商造成严重的经济损失。该项目旨在确定商业奶牛群在围产期优化初乳质量和奶牛及小牛健康的营养策略。具体而言，B族维生素在与能量和蛋白质代谢、DNA甲基化和细胞生长相关的几个反应中具有重要作用。这些维生素是由受奶牛营养影响的瘤胃细菌产生的。我们假设，某些类型的产前口粮，不使用B族维生素补充剂，优化B族维生素的状态，在围产期的母亲和初乳。小牛摄入这种初乳将有益于增加其B族维生素供应，并可能改善表观遗传编程，因为维生素B 9在DNA甲基化中发挥作用。小牛出生时没有功能性瘤胃，依靠维生素B供应来满足其需求。通过产犊前饮食和犊牛状况优化分娩前后母畜B族维生素状况将减少奶牛和犊牛的健康问题，从而避免经济损失。在这个项目中，总共将对75个加拿大牛群和375对母牛-小牛进行血液采样。B族维生素母体状态、初乳免疫球蛋白浓度和表观遗传特征之间的联系将被完成。评估影响初乳免疫球蛋白浓度的营养因素以使其浓度最大化是至关重要的。为供伙伴组织使用，将制定关于饮食类型的建议（例如，玉米青贮饲料的百分比）或营养组合物（例如，在这一具有挑战性的时期，通过添加不同比例的纤维和淀粉（纤维和淀粉的百分比）来促进产犊前的配给，以优化奶牛和小牛的B族维生素状态以及初乳的B族维生素和免疫球蛋白浓度，从而最大限度地提高它们的健康。

The transition period from -3 to 3 weeks relative to the parturition is challenging for modern dairy cows as several health problems might occur. For instance, an inadequate precalving diet can exacerbate the state of negative energy balance in early lactation and then favor an excessive body reserve mobilization leading to metabolic diseases. Calves are born with a non-functionnal immune system and they rely on colostrum consumption to get immunoglobulin to fight against potential infectious agents. Early lactation and early life problems for cows and calves, respectively, cause severe monetary loss for dairy producers. This project aims to identify nutritional strategies optimizing colostrum quality and cow and calf health during the peri-partum period in commercial dairy herds. Specifically, B vitamins have important roles in several reactions linked to energy and protein metabolism, DNA methylation and cell growth. These vitamins are produced by rumen bacteria which are affected by cow nutrition. We hypothesize that certain types of precalving rations, without the use of B-vitamin supplements, optimize B-vitamin status of the dam during the peri-partum period and of the colostrum. Intake of this colostrum by the calves would be beneficial by increasing their B-vitamin supply and possibly by improving epigenetic programmation as vitamin B9 has a role in DNA methylation. Calves do not have a functional rumen at birth and rely on B-vitamin supply to fulfill their requirements. Optimizing dam B-vitamin status around parturition through the precalving diet as well as the calf status would decrease cow and calf health problems and then avoid monetary loss. A total of 75 Canadian herds and 375 cow-calf pairs will be blood sampled in this project. Links between B-vitamin maternal status, colostral immunoglobulin concentrations and epigenetic profile would be done. It is essential to assess nutritional factors influencing colostral immunoglobulin concentration to maximize their concentrations. For the use of the partner organizations, recommandations would be developed on diet type (ex. percentage of corn silage) or nutritive composition (ex. percentages of fiber and starch) to favor in pre-calving rations to optimize B-vitamin statuses of the cow and the calf and B-vitamin and immunoglobulin concentrations of the colostrum to maximize their health during this challenging period.