Effect of the Reduction in the Frequency of Injections of Pituitary Extracts During a Superovulation on the Embryo Collection Results in Cows in Algeria

Abstract

The aim of this study is to verify the efficacy of a superovulation treatment with 3 injections of pituitary extracts (Stimufol®) 24 hours apart and compare the results to a standard protocol (8 injections 12 hours apart), with a total dose of 500 μg. Twenty-three embryos collections were conducted after two superovulation protocols, the first with 8 injections 12 hours apart and decreasing doses (n = 11, group 1) and the second 3 injections at constant doses 24 hours of interval (n = 12, group 2). The average number of lutea corpora obtained is 9.1 per cow for group 1 and 10.4 in group 2. A total number of 140 embryos were collected with an average of 6.08 per cow. Among the embryos collected, 46 and 56 per cent were transferable respectively in group 1 and 2. A little quality gain was recorded in group 2 with an average transferable embryo of 3.8 against 2.2 for group1. In our study we observed the same efficacy for both treatments with a little quality improvement (almost one transferable embryo) when reducing the number of injections at the time of superovulation treatment, the same gain minimal in elite cows can have a significant economic impact.