Department of Animal, Veterinary and Food Sciences, University of Idaho, Twin Falls, ID 83301, USA.
Department of Animal Science, Universidade Federal de Pelotas, RS 96010-900, Brazil.
Animal. 2024 Sep;18 Suppl 2:101219. doi: 10.1016/j.animal.2024.101219. Epub 2024 Jun 19.
Goats play an important role in the agricultural business, providing valuable income sources through producing high-quality animal protein. They are widespread livestock for rural households due to their inherent resiliency, adaptability to many environments, and suitability in sustainable production systems. While goats are reared in highly diverse environments, a great portion of their population is reared in hot environments. Heat stress is known to affect goats' productive and reproductive performance negatively. However, goats can remarkably thrive in harsh conditions due to physiological, metabolic, and molecular adaptive mechanisms. In the face of it, in the last decades, the nutrition of goats, particularly their nutritional requirements, has received special attention. Research groups worldwide have dedicated their efforts to updating feeding systems for goats. Our objective was to present the recent findings on the energy and nutrient requirements of growing and pregnant goats in hot environments. Energy and protein requirements for the maintenance and growth of goats are influenced by sex and genotype only when mature weight is not considered in the models. Sex and genotype affect the efficiency of energy use for growth but do not affect the efficiency of protein use. Major mineral requirements for maintenance and growth are not affected by sex, except for magnesium. However, the phosphorus, sodium, and potassium requirements of goats raised in hot environments differ from those in the feeding systems. This difference may be related to the adaptation mechanisms goats employ to cope with the hot environmental conditions. Regarding requirements for pregnancy, there was no effect of days of pregnancy on the energy or protein requirements. The efficiency of metabolizable energy utilization for pregnancy increased with the progress of pregnancy. Mineral accretion for pregnancy differs between single and twin pregnancies and, irrespective of pregnancy type, the mineral requirements increase as pregnancy progresses. The differences between the estimated dietary requirements of goats raised in hot environments and the most widely adopted feeding systems suggest that these goats may be using energy and nutrients to cope with heat stress and other stressors associated with hot environments. The recent findings on energy, protein, and mineral requirements of growing and pregnant goats can be an important resource of information for enhancing feeding systems worldwide.
山羊在农业生产中扮演着重要的角色，通过生产高质量的动物蛋白，为农村家庭提供了有价值的收入来源。由于其内在的弹性、对多种环境的适应性以及在可持续生产系统中的适宜性，山羊是农村家庭广泛饲养的家畜。虽然山羊在高度多样化的环境中饲养，但很大一部分山羊在炎热的环境中饲养。众所周知，热应激会对山羊的生产性能和繁殖性能产生负面影响。然而，由于生理、代谢和分子适应机制，山羊可以在恶劣的条件下茁壮成长。面对这种情况，在过去的几十年里，山羊的营养，特别是它们的营养需求，受到了特别的关注。世界各地的研究小组都致力于更新山羊的饲养系统。我们的目的是介绍在炎热环境中生长和怀孕的山羊的能量和营养需求的最新研究结果。只有在不考虑模型中成熟体重的情况下，性别和基因型才会影响山羊维持和生长的能量和蛋白质需求。性别和基因型会影响能量用于生长的效率，但不会影响蛋白质利用的效率。除了镁之外，维持和生长的主要矿物质需求不受性别影响。然而，在炎热环境中饲养的山羊对矿物质的需求与饲养系统中的需求不同。这种差异可能与山羊为应对炎热的环境条件而采用的适应机制有关。关于怀孕的需求，怀孕天数对能量或蛋白质需求没有影响。随着怀孕的进展，可代谢能用于怀孕的效率增加。怀孕的矿物质积累在单胎和双胎妊娠之间存在差异，并且无论妊娠类型如何，随着妊娠的进展，矿物质需求都会增加。在炎热环境中饲养的山羊的估计日粮需求与最广泛采用的饲养系统之间的差异表明，这些山羊可能正在利用能量和营养物质来应对热应激和与炎热环境相关的其他应激源。关于生长和怀孕山羊的能量、蛋白质和矿物质需求的最新研究结果可以为世界各地的饲养系统提供重要的信息资源。
