Comparative studies on the evaluation of productive traits and its efficient use in buffaloes

众所周知，家养水牛对湿热的热带环境具有良好的适应性，并且比牛更有效地利用粗饲料。本研究旨在通过与相同年龄和相同饲养条件的牛进行比较，从以下方面描述水牛的生理和生产特征：1）体温调节反应，2）饲料利用和育肥性能，以及3）繁殖特征。研究结果如下：1）水牛比牛表现出更高的体内水分周转率和更低的通过出汗和皮肤表面水分蒸发散热的能力，而水牛的蓄热能力和敏感散热能力必然较高，这些特性使得水牛能够很好地耐受炎热环境。 (参考1和2)2) 水牛比牛表现出优异的干物质消化率和更有效的饲料能量利用率，并且如果在幼年时饲养和喂养得当，它们就会表现出与肉牛一样高的良好产肉性能。 （参考文献3、4和6）3）为了克服水牛超排卵和体外受精胚胎生产效率较低的问题，已经进行了将水牛体细胞核移植到牛卵母细胞的尝试。结果，成功获得形态正常的囊胚期胚胎，即属间核移植胚胎。 (ref.5)4) 这些研究结果表明，家养水牛经过长期的进化，形成了其独特的生理和生态特征，能够很好地适应炎热和潮​​湿的环境，并表明水牛是热带地区很有前途的肉类和奶类生产动物。

It has been known that domestic buffaloes have a good adaptability to hot-humid tropical environments and can utilize coarse fodder more efficiently than cattle. This study aimed at to characterize the physiological and productive traits of buffaloes in terms of 1) thermoregulatory responses, 2) feed utilization and fattening performance, and 3) reproductive traits, by comparing the traits to those of cattle with same ages and same feeding conditions. Research results obtained are as follows :1) Buffaloes show a higher body water turn over rate and lower heat dissipation ability by sweating and water evaporation from skin surface than in cattle, while the heat storage capacity and sensitive heat dissipation are inevitably high in buffaloes, and these characteristics allow the buffalo well-tolerate hot environments. (ref.1 and 2)2) Buffaloes show a superior digestibility of dry matter and more efficient feed energy utilization rates than cattle, and, if raised and fed properly at young ages, they show a good meat-producing performance as high as beef cattle. (ref.3, 4 and 6)3) To overcome less efficient yield for embryo production by super ovulation and in vitro fertilization in buffaloes, an attempt of nuclear transfer of buffalo somatic cells to cattle oocytes has been conducted. As a result, the morphologically normal embryos at blastocyst stage, a inter-generic nuclear-transferred embryo, were successfully obtained. (ref.5)4) These research results demonstrate that the domestic buffaloes have developed their unique physiological- and ecological traits through long-term evolutional period being well-adapted to hot and humid environments, and show that the buffalo is a promising animal in the tropics as a meat and milk producer.