Nutrition and Food in the Reproduction of Cattle
Nutrition and Food in the Reproduction of Cattle
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牛繁殖中的营养和食物
DOI：
10.34297/ajbsr.2019.06.001000
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
A. Córdova
中科院分区：
文献类型：
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作者：
A. Córdova
20 世纪 80 年代初，由于北半球的生产系统达到了每头奶牛的最高产量，奶牛营养方法发生了一系列非常深刻的变化。营养被定义为有机体获取和吸收食物以促进其生长并更换磨损或受损组织的一系列过程。营养物质是动物发挥不同生产功能的基础。当我们考虑涉及反刍动物营养领域的方面时，我们了解这组具有动物学意义的动物的重要性，它们能够加工其他哺乳动物不消耗的植物成分，即结构性碳水化合物（纤维）。反刍动物来自“rumen”这个词，它是牛、绵羊或山羊胃的四个隔室中最大的隔室。这个结构是微生物发酵发生的地方。反刍动物通过进化过程，与微生物建立了生命关系，使它们能够利用纤维作为食物，也就是说，它们以某种方式发展了它们的“食物工厂”。它们吃的草料被瘤胃微生物群转化为动物能量来源的物质，并且对于微生物合成来说，微生物细胞是动物蛋白质的极好来源。然而，瘤胃微生物群的形成过程在某种程度上是低效的。草退化产生挥发性脂肪酸、微生物蛋白质和气体。这些气体中，有一些是环境污染物，例如二氧化碳、甲烷和一氧化二氮。数以百万计的细菌、原生动物和真菌生活在瘤胃中，降解植物中富含能量的部分，使它们易于被动物宿主消化。草料在瘤胃中被消化并降解成较小的部分后，它可以通过网胃和瓣胃，网胃和瓣胃的作用就像漏勺，捕获大块物质，防止它们到达皱胃或“真正的胃”，在那里继续消化。反刍动物的营养关注点集中在能量（即碳水化合物）、蛋白质、矿物质、维生素和水。能量（碳水化合物）负责动物的生长和维持功能以及产生热量。该蛋白质使组织生长并执行其他重要功能。其他营养物质和矿物质如维生素A和E、钙、磷、硒等可以作为矿物质补充品“自由选择”喂养。具有高生产潜力（9000-12000/升/泌乳期）的奶牛目前对营养构成了真正的挑战。多年来，已有证据表明营养对雌性牛的繁殖行为有影响。影响繁殖的主要因素是由于食物稀缺和质量造成的营养不良。随后的研究表明，营养作用是通过各个方面之间复杂的相互关系来发挥的，例如：身体储备的含量和使用、不同系统和器官之间营养物质的分配以及除繁殖之外的各种功能的营养物质使用的优先顺序。
At the beginning of the 1980s, a series of very profound changes were initiated in the milk cow nutrition approaches, as a consequence of the highest levels of production per cow that were reached by the productive systems of the northern hemisphere. Nutrition is defined as the series of processes through which an organism acquires and assimilates food to promote its growth and replace worn or damaged tissues. The nutrients are fundamental for the animals to carry out their different productive functions. When we consider the aspects that touch the field of nutrition of ruminants, we understand the importance of this group of animals of zootechnical interest, which are able to process plant components that are not consumed by other mammals, the structural carbohydrates (fiber). Ruminant comes from the word "rumen", which is the largest of the compartments in the stomach of four compartments of a bovine, sheep, or goat. This structure is where microbial fermentation takes place. The ruminants, through evolutionary processes, developed life relationships with microorganisms which enabled them to use fiber as food, that is, they developed in some way their "food factory". They eat the forage to be transformed by the rumen's microbiota into substances that are the source of energy for the animal and for the microbial synthesis, the microbial cells are an excellent source of proteins for the animal. However, the processes that make the ruminal microbiota are, in a certain way, inefficient. Grass degradation produces volatile fatty acids, microbial protein and gases. Within these gases, some are environmental pollutants such as CO2, methane and nitrous oxide. Millions of bacteria, protozoa, and fungi live in the rumen and degrade parts of the plant rich in energy, making them digestible to the animal host. After the forage has been digested in the rumen and degraded to smaller parts, it can pass through the reticulum and omasum, which function as colanders that trap large pieces of material preventing them from reaching the abomasum, or "true stomach", where digestion continues. The nutritional concern for ruminants focuses on energy (ie, carbohydrates), protein, minerals, vitamins, and water. The energy (carbohydrates) is responsible for the functions of growth and maintenance of the animal, and the generation of heat. The protein makes the tissue grow and performs other vital functions. Other nutrients and minerals such as vitamin A and E, calcium, phosphorus, and selenium can be fed to "free choice" as a mineral supplement. Dairy cows of high productive potential (9000-12000 / liters / lactation) currently represent a real challenge for nutrition. For many years, there has been evidence of the impact of nutrition on the reproductive behavior of the bovine female. The main factor that affects reproduction is the undernourishment due to the scarcity and quality of the food. Subsequent research has shown that nutritional effects are exerted through complex interrelations between various aspects such as: content and use of body reserves, distribution of nutrients between different systems and organs and prioritization of the use of nutrients for various functions in addition to reproduction.