REDR1998 Reproduction in Domestic Ruminants IV Comparative Reproductive Function: Implications for Management (4 abstracts)
1Institut National de la Recherche Agronotnique, Station de Physiologie de la Reproduction des Mammiferes Domestiques, URA CNRS 1291, 37380 Nouzilly, France; 2Institut National de la Recherche Agronomique, Station Experimentale dInsémination Artificielle 86480 Rouillé, France
The control of reproduction in goats is interesting for technical reasons (synchronization of kiddings, adjustment to forage availability or to economy), and for genetic reasons (identification and dissemination of improved genotypes). The use of short-light rhythms leads to markedly increased production of semen per buck and prevents occurrence of a resting season. Recent identification of a bulbourethral lipase in goat spermatozoa opens new perspectives in sperm preservation. Light plus short day treatments also allow induction of out-of-season oestrous cycles and ovulations leading to enhanced fertility. Repeated use of eCG provokes the production of antibodies, delays the timing of ovulation and causes a reduction in fertility after fixed-time artificial insemination. All steps of embryo production, freezing and transfer are now controlled and allow the attainment of satisfactory numbers of kids bom per donor female, which are compatible with the development of the technique for exchanging genotypes between countries. In vitro production of embryos allows high development rates to be achieved after in vitro maturation and fertilization of oocytes, and will ensure the production of synchronous populations of one-cell zygotes at the stage required by new biotechnologies.
© 1999 Journals of Reproduction and Fertility Ltd