Evaluation of hormone-free protocols based on the "male effect" for artificial insemination in lactating goats during seasonal anestrus.

Goat estrous and ovulatory responses to the "male effect" were characterized to determine the time range over which fertile ovulations occur after buck exposure. The results were used to explore the efficacy of different hormone-free artificial insemination (AI) protocols aimed at diminishing the number of inseminations needed to optimize fertility. Adult bucks and does were exposed to artificially long days during winter and then exposed to a natural photoperiod before buck exposure (Day 0).

Sex and PRNP genotype determination in preimplantation caprine embryos.

The objective of this study was to test the accuracy of genotype diagnosis after whole amplification of DNA extracted from biopsies obtained by trimming goat embryos and to evaluate the viability of biopsied embryos after vitrification/warming and transfer. Whole genome amplification (WGA) was performed using Multiple Displacement Amplification (MDA). Sex and prion protein (PRNP) genotypes were determined.

High fertility using artificial insemination during deep anoestrus after induction and synchronisation of ovulatory activity by the "male effect" in lactating goats subjected to treatment with artificial long days and progestagens.

The response to the male effect was studied in two Saânen and two Alpine flocks over 5 consecutive years. Adult male and female goats were exposed to artificial long days (16h light and 8h darkness, 16L:8D) in open barns for approximately 3 months (between December 1 and April 15) followed by a natural photoperiod. Goats were treated for 11 days with fluorogestone acetate (FGA) or progesterone (CIDR) immediately before joining.

Highly synchronous and fertile reproductive activity induced by the male effect during deep anoestrus in lactating goats subjected to treatment with artificially long days followed by a natural photoperiod.

The response to the male effect was studied in two flocks of Saanen and three of Alpine goats during deep anoestrus in three consecutive years. Males and females were subjected to artificially long days for about 3 months (between December 4 and April 1) followed by a natural photoperiod. Bucks joined goats 42-63 days after the end of the long days treatment (between April 20 and June 3) and fertilisation was ensured by natural mating.

Efficacy of two types of vaginal sponges to control onset of oestrus, time of preovulatory LH peak and kidding rate in goats inseminated with variable numbers of spermatozoa.

In small ruminants, progestagen-impregnated vaginal devices (sponges) are useful tools to manage reproduction irrespective of season and to the application of timed artificial insemination (AI). A novel progestagen releasing vaginal-controlled release device (Chronogest CR), loaded with less (20mg) cronolone using proprietary procedures, was developed and its efficacy (synchronising ability, fertility and prolificacy following sponge removal) evaluated versus the existing Chronogest sponge containing 45 mg of cronolone in goats. Females (n=199) were maintained in field conditions and inseminated with graded amounts of spermatozoa at two stages of the year (breeding and non-breeding seasons).