Determination of the minimal dose of iliren capable of inducing estrus in alpine goats

ABSTRACT

Various doses of iliren [0.25, 0.5, 0.75 and 1ml] were injected to 36 cycling Alpine dairy goats during 7-10 days of estrous cycle. Another 9 goats were injected with 1 ml saline served as control. All does were teased twice daily with a fertile buck and observed for sings of estrus for 5 days post-injection. Pre and post injection daily progesterone assay were determined. The results revealed that the mean concentration of progesterone in all does on the day of injection was 3.4 +/- 0.5 ng/ml. Concentration 24 hours post-injection were 0.2 +/- 0.02,0.15 +/- 0.05, 0.17 +/- 0.04, 0.16 +/- 0.05 and 4.5 +/- 1.1 ng/ml for does receiving 0.25, 0.5, 0.75,1 ml of iliren and 1ml saline respectively. The results indicated that 0.25 ml iliren was the minimal dose effective for induction of estrus in cycling does. Estrus was synchronized using 0.25 ml of iliren [2 injections 11 days apart] into 45 cycling does. Another 45 does injected with 1 ml saline at the same period serve as control. The does exhibited estrus were mated by a fertile buck. The pregnancy rate, kidding rate, and litter size were recorded in both Seventy one percent [32/45] of the does initially treated with 0.25 ml iliren came to heat within 48 +/- 4 hours after injection. Estrus was observed within 46 +/- 2 hours in 44 out of 45 does [97.9%] treated 11 days later with second injection of 0.25 ml iliren. No significant differences in the pregnancy rate were observed between the treated and the control groups. It could be concluded that the use of 0.25 ml i.m.of iliren was the minimal dose capable of inducing estrus in Alpine does. Moreover this dose was used 2 time with 11 days apart it was highly effective in synchronizing estrus in does. Fertility in comparison with the control was not altered