Cyclic reproductive activity and efficiency of reproduction in Serrana goats

Reproductive efficiency was studied in mature Serrana goats in three commercial units with ovarian activity being assessed from plasma progesterone profiles between October and May. Over a 2 year period, the mean fertility was 76.2% and the prolificacy was 1.73. Parturitions were recorded between 1 October and 28 February, with 50% of them occurring before the end of October. Goats kidding in October had a significantly shorter (P<0.01) postpartum anoestrous period in the first year (33.0±9.4 days; n = 20) than in the second year of this experiment (50.3±19.7 days; n = 20). Ovarian activity, assessed by plasma progesterone profiles, was low in October (postpartum anoestrus), increased until early January, then declined suddenly to less than 3% and remained low until the first week of May (seasonal anoestrus) when the breeding period commenced. ta suggest that Serrana goats have a period of anoestrus from January to May. Fertility in the beginning of the breeding period (May) could be improved by adequate management techniques so that most parturitions occur in October/November.