Current Topics in Artificial Insemination of Sheep

Abstract

There have been developments in several aspects of artificial insemination (AI) in recent years, some of which have been directly responsible for proliferation of AI in the sheep-breeding industries of several countries. The most notable advances have probably been associated with the development of intrauterine insemination by laparoscopy. There is potential for refinement of some of the related techniques, particularly in the area of control of ovulation and definition of appropriate times and optimum doses of spermatozoa for insemination. It is unlikely that laparoscopic AI will be developed sufficiently that it will become readily affordable, and therefore widely practised, by commercial producers.

Fertility of young Cashmere goats after laparoscopic insemination

“…However, the critical threshold may be reached at different total numbers of spermatozoa depending on the semen freezing method. Evans (1988) also suggested that, in the ewe, additional investigations need to be undertaken under various conditions to determine the minimum dose of motile spermatozoa to maintain fertility rates.…”

Recent developments and concepts in the cryopreservation of spermatozoa and the assessment of their post-thawing function

“…A study of the fundamentals of cryoinjury in spermatozoa is now being undertaken, and is reviewed in this article. The aim of this review is not to provide an exhaustive account of the cryopreservation of spermatozoa species by species; that has been done in several reviews recently (Amann and Pickett 1987;Evans 1988;Watson 1990;Bwanga 1991;Klug et al 1992). Rather, it will attempt to present the author's perspective on the subject, emphasizing those areas of development in which it is considered the most useful progress is being made, or could be made if resources were devoted to those aspects.…”

Influence of fetuin and hyaluronan on the post-thaw quality and fertilizing ability of Holstein bull semen

“…The preservation of sperm generally requires a reduction or arrest of the metabolism of sperm cells, and thereby, prolongs their fertile life [39,59]. Cryopreservation produces cold shock and oxidative attack on the sperm membrane, both of which decrease the survival and fertilizing ability of sperm, and thus, lead to sperm death and a negative impact on the preservation of semen for AI [27,38]. The cold shock of spermatozoa is partly associated with oxidative attack and the generation of reactive oxygen species (ROS).…”