Smeaton D C, Harris B L, Xu Z Z, Vivanco W H
AgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, New Zealand.
Theriogenology. 2003 Jan 15;59(2):617-34. doi: 10.1016/s0093-691x(02)01244-x.
New reproductive technologies include sexed sperm and embryo-based technologies. The technology of sperm sexing, for various reasons, is not available in New Zealand and its use has not been modelled. Embryo technologies are however already in use on a limited scale and various scenarios for their use in both the dairy and beef industries in New Zealand have been modelled. This review briefly discusses the various technologies available and some of their potential strengths and weaknesses. In the dairy industry, modelling has been used to simulate the production of breeding bulls for large breeding companies and the production of replacement heifers in dairy herds. For the beef industry, similar modelling has been carried out to determine the opportunities for more efficient beef production. All the models confirmed that at current levels of performance, embryo-based reproductive technologies are usually not profitable in New Zealand except in niche market situations where the returns from the resulting offspring are significantly greater than can be obtained from natural mating or artificial insemination (AI) reproduction systems. This is confirmed by the low uptake of these technologies in this country to date. Even if performance lifts to levels similar to AI, profitability is likely to occur only if the costs of pregnancies to embryo-based reproductive technologies can occur at prices less than two to four times greater than AI or natural mating. This break-even requirement depends on the returns that can be achieved and the advantages that can be captured by the technology over and above those available from AI or natural mating. Two new uses for reproductive technologies in dairy cattle could be the proliferation of novel or rare genotypes from gene discovery programs and improving the female reproductive rate for optimal marker assisted selection. In both these uses the technology is not at present competing with AI or natural mating. The challenge exists therefore for the biological scientists to satisfy these requirements, coupled with the ethical and human factors involved in the introduction of any new technology. Potential end users of the technologies have been surveyed. They are quite positive about the technologies provided they can use them profitably and are keen to obtain more information about them.
新的生殖技术包括精子性别筛选技术和基于胚胎的技术。出于各种原因，精子性别筛选技术在新西兰无法使用，也未对其应用进行模拟。然而，胚胎技术已在有限范围内使用，并且已对其在新西兰奶牛业和肉牛业中的各种应用场景进行了模拟。本综述简要讨论了现有的各种技术及其一些潜在的优点和缺点。在奶牛业中，已通过建模来模拟大型育种公司种公牛的生产以及奶牛群中后备小母牛的生产。对于肉牛业，也进行了类似的建模以确定提高牛肉生产效率的机会。所有模型均证实，就目前的性能水平而言，基于胚胎的生殖技术在新西兰通常无利可图，除非在特定的利基市场情况下，即由此产生的后代的回报明显高于自然交配或人工授精（AI）繁殖系统所能获得的回报。该国目前对这些技术的低采用率证实了这一点。即使性能提升到与人工授精相似的水平，只有当基于胚胎的生殖技术的妊娠成本低于人工授精或自然交配成本的两到四倍时，才可能实现盈利。这一收支平衡要求取决于所能获得的回报以及该技术相对于人工授精或自然交配所能获得的优势。奶牛生殖技术的两个新用途可能是基因发现计划中新型或稀有基因型的繁殖，以及提高雌性生殖率以实现最佳标记辅助选择。在这两种用途中，该技术目前并未与人工授精或自然交配竞争。因此，生物科学家面临着满足这些要求的挑战，同时还要考虑引入任何新技术所涉及的伦理和人为因素。已对这些技术的潜在最终用户进行了调查。他们对这些技术相当积极，前提是他们能够从中获利，并渴望获得更多相关信息。
