Abstract:
Considerable progress in reproduction of dairy goats has been made, with advances in reproductive technology accelerating dairy goat production since the 1980s. Reproduction in goats is described as seasonal. The onset and length of the breeding season is dependent on various factors such as breed, climate, physiological stage, male effect, breeding system, and photoperiod. The reproductive physiology of goats was investigated extensively, including hypothalamic and pituitary control of the ovary related to estrus behavior and cyclicity etc. Photoperiodic treatments coupled with the male effect allow hormone-free synchronization of ovulation, but the kidding rate is still less than for hormonal treatments. Different protocols have been developed to meet the needs and expectations of producers; dairy industries are subject to growing demands for year round production. Hormonal treatments for synchronization of estrus and ovulation in combination with artificial insemination (AI) or natural mating facilitate out-of-season breeding and the grouping of the kidding period. The AI with fresh or frozen semen has been increasingly adopted in the intensive production system, this is perhaps the most powerful tool that reproductive physiologists and geneticists have provided the dairy goat industry with for improving reproductive efficiency, genetic progress and genetic materials transportation. One of the most exciting developments in the reproduction of dairy animals is embryo transfer (ET), the so-called second generation reproductive biotechnology following AI. Multiple ovulation and ET (MOET) program in dairy goats combining with estrus synchronization (ES) and AI significantly increase annual genetic improvement by decreasing the generation interval. Based on the advances in reproduction technologies that have been utilized through experiments and investigation, this review will focus on the application of these technologies and how they can be used to promote the dairy goat research and industry development in the future.
摘要:
奶山羊的繁殖已取得相当大的进展,随着生殖技术的进步,自20世纪80年代以来加速了奶山羊的生产。山羊的繁殖被描述为季节性的。繁殖季节的开始和长度取决于各种因素,例如品种,气候,生理阶段,男性效应,育种系统,和光周期。对山羊的生殖生理进行了广泛的调查,包括下丘脑和垂体对卵巢的控制,与发情行为和周期性等有关。光周期治疗加上男性效应允许无激素同步排卵,但是开玩笑的比率仍然低于激素治疗。已经制定了不同的协议来满足生产者的需求和期望;乳制品行业受到全年生产日益增长的需求。与人工授精(AI)或自然交配相结合的发情和排卵同步激素治疗可促进反季节繁殖和开玩笑期的分组。在集约化生产系统中越来越多地采用新鲜或冷冻精液的AI,这也许是生殖生理学家和遗传学家为奶山羊行业提供的提高生殖效率的最有力工具,遗传进展和遗传物质运输。奶牛繁殖最令人兴奋的发展之一是胚胎移植(ET),所谓的继人工智能之后的第二代生殖生物技术。奶山羊的多次排卵和ET(MOET)程序与发情同步(ES)和AI相结合,通过减少世代间隔,显着提高了年度遗传改良。根据通过实验和调查利用的繁殖技术的进步,本文将重点介绍这些技术的应用,以及如何在未来促进奶山羊的研究和产业发展。