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，能够比牛更有效地利用粗饲料。本研究旨在通过与同龄、相同饲养条件的水牛进行比较，从体温调节反应、饲料利用和育肥性能、繁殖性能等方面对水牛的生理和生产性能进行表征。研究结果如下：1)水牛的体水周转率高于黄牛，体表出汗和水分蒸发的散热能力低于黄牛，而水牛的储热能力和敏感散热能力必然较高，这些特点使水牛对高温环境具有良好的耐受性。(参考文献1和2)水牛表现出比牛更好的干物质消化率和更高的饲料能量利用率，如果在年轻时正确饲养和饲养，它们表现出与肉牛一样好的产肉性能。(参考文献3、4和6)为了克服水牛超数排卵和体外受精胚胎生产效率低的问题，进行了水牛体细胞核移植到牛卵母细胞的尝试。成功地获得了囊胚期形态正常的跨属间核移植胚胎。(参考文献5)4)这些研究结果表明，家牛在长期的进化过程中形成了独特的生理和生态特征，适应了炎热潮湿的环境，表明水牛是一种很有前途的热带肉类和牛奶生产国。

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.