Review of reproductive performance of female Bos indicus (zebu) cattle

taurus species, they are often characterized by low reproductive and fertility rates. This monograph reviews the reproductive performance of female zebu cattle in tropical areas and explores possible improvements to it. After a brief introduction to the reproductive anatomy and endocrinology of the cow, subsequent chapters describe: (1) changes which occur at puberty, during the estrous cycle, and at pregnancy; (2) general and specific measures of reproductive performance; (3) causes of infertility, and how these can be diagnosed and their effects minimized; (4) the role of nutrition in cattle reproduction; and (5) lactational anestrous and its effect on weaning. Summaries and extensive bibliographies accompany each chapter. The study finds that among the most common forms of functional infertility in cows are faulty estrous manifestation, e.g., cystic ovaries, and infections of the reproductive tract. Inadequate nutrition also hinders reproduction by delaying puberty and sexual maturity in heifers and the resumption of ovarian and estrous cycles in postpartum cows. Crossbreeding with B. taurus is one solution to the depressed fertility and fitness traits which occur during inbreeding of zebu, but careful monitoring is essential, as high levels of taurine blood are disadvantageous in tropical areas. The final chapter outlines a herd health program, while cautioning that therapeutic interventions are no substitute for sound husbandry.