Effect of Repeated Use of Progestagen-PMSG Treatment for Estrus Control in Dairy Goats out of Breeding Season

Anti-PMSG antibody levels in sheep subjected annually to oestrus synchronisation

“…Anti-PMSG antibodies had previously been suspected in cattle (Willet et al, 1953) as in ewes (Hulet and Foote, 1969;Clarke, 1973;Gherardi and Martin, 1978) which had suddenly shown lower rates of embryo recovery. Several subsequent studies demonstrated these antibodies in goats (Baril et al, 1992a, b), cattle (Jainudeen et al, 1966) and rabbits (Canali et al, 1991 (Baril et al, 1992a, b (Baril et al, 1992a, b), and in ewes when the delay between injections is only 1 month (Rainio, 1992 (Baril et al, 1992b). As had been previously observed (Rainio, 1992), and also noted in our experiment, older ewes have higher residual binding rates.…”

“…As had been previously observed (Rainio, 1992), and also noted in our experiment, older ewes have higher residual binding rates. This may be explained, as it was for goats (Baril et al, 1992b) …”

“…Studies on cattle (Willet et al, 1953;Christie et al, 1979;Alwan et al, 1988), and goats (Maurer et al, 1968;Gherardi and Martin, 1978;Armstrong et al, 1983;Remy et al, 1991;Baril et al, 1992b;Beckers et al, 1995) (Pignon et al, 1960;Jainudeen et al, 1966;Maurer et al, 1968;Alwan et al, 1988;Bavister et al, 1986;Remy et al, 1991;Baril et al, 1992b). Moreover, Beckers et al (1995) showed that goats treated with eCG, transmitted anti-eCG antibodies in their colostrum.…”

Evolution of anti-eCG antibodies in response to eCG doses and number of injections. Relationship with productivity of rabbit does

“…The goat seems to be the most reactive with repeated administrations of gonadotrophins (Drion et al, 1998). Indeed, 36% of the females receiving one or two eCG treatments at the first insemination presented a sufficient immune response to compensate for the successful estrus induction treatment (Baril et al, 1992). The immune reaction induces an increase in the frequency of late estrus, associated with a low fertility.…”

“…In ovine and caprine production, this molecule is routinely used to induce and synchronize estrus and ovulation and is consequently a prerequisite to insemination. However, the repeated use of eCG is generally followed by a decrease in fertility in some ewes and goats, a consequence of the apparition of plasmatic anti-eCG antibodies (Baril et al, 1992;Bodin et al, 1995;Roy et al, 1995). Indeed, its proteinic and exogenic nature associated with its high molecular weight could reduce its efficiency in case of prolonged use in rabbit does also.…”