Effects of PMSG induced oestrus on the performances of rabbit does: a review +

• Autores: L. Maertens, F. Luzi, G. Grilli
• Localización: World Rabbit Science, ISSN-e 1989-8886, ISSN 1257-5011, Vol. 3, Nº. 4, 1995, págs. 191-199
• Idioma: inglés
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• Resumen

  • Although the rabbit is considered as a mammal with an extreme high reproduction capacity, the irregular alternation of oestrous and anoestrous periods is a disadvantage in view of a regular, synchronized reproduction rhythm. Especially with the increasing use of artificial insemination in rabbit breeding, large groups of females in the same reproductive and pllysiolog1cal stage are likely. However, the receptivity of the ooe is largely aepending on the hormonal antagonism between prolactin and gonadotropin. In order to salve this problem, last years an increasing use of a Pregnant Mare Serum Gonadotropin (PMSG) treatment, 2 to 3 days before the insemination, became widespread.The authors reviewed the literature concerning the effects of a PMSG treatment in arder to synchronize the oestrus. The following beneflts generally determined were:-              an increase of the sexual receptivity to the male; about 90 % accept the male 2-3 days after the treatment.-              especially in lactating non receptiva does, receptivity and fertihty were significantly increased.-              an increase of the prolificacy; total litter size: + 5 to 10 %-              positive results on does with reproductiva problems. However, a number of dlsadvantages were found:-              the lack of improvement in non-lactating or receptiva does.-              because of antigenic properties, a decrease in fertility after repeated treatments.-              an increase of the mortality rate at birth, probably related to the dosage used.-              a changed distribution of litter size frequencies: larga litters (> 12 young) and small litters (<5 young) are more numerous. Based on these observations, the authors advise to consider the application of PMSG induced oestrus only in relation to the physiological status of the doe and at a low dosage. Limited use on primiparous does and (or) on non-receptiva does can help to synchronize the oestrus and to obtain more favourable results in a well organized reproduction scheme. However, further research efforts have to be done in order to optimize feeding, zootechnical and environmental conditions in view of oestrus synchronization and to avoid the systematic use of PMSG.