Effects of using melatonin implants and syncro-part pessaries + PMSG on reproduction performance in transylvanian merino breed ewes.

Investigations were carried out in a commercial farm from Sinnicolau Mare, western Romania, on a number of 70 yearling ewes of 17-18 months of age from the native Transylvanian Merino breed. Ewes included into study lambed for the first time as maiden-ewes at the age of 14-15 months, with their lambs being weaned at the age of two months. First group (V1), numbering 25 ewes received during out of season breeding (30.05.2011) a dose of 18 mg subcutaneous melatonin implants (Melovin®), while the second group (V2) consisting out of 25 ewes were treated with subcutaneous melatonin implants + 30 mg FGA (Syncro-Part pessaries) + 500 IU PMSG. Control group was represented by 20 intact females. Ewes were put to ram in July 7 th 2011. Researches shown that in ewes treated with melatonin, 30 mg FGA + 500 IU PMSG (V2) the conception rate was of 80%, with a prolificacy of 140%, with a weaning rate of 1 lamb/ewe. In V1 group, the weaning rate was of 0.84 lambs/ treated ewe, with significantly lower production costs. Ewes from the control group produced a weaning rate of 0.55 lambs/ewe, significantly less (p≤0.05) comparing to V1 and V2 experimental groups. It was concluded that in Transylvanian Merino breed, although the V2 group performed best (producing 28 lambs) compared to V1 group (23 lambs), the difference of 5 lambs does not cover additional production costs, therefore the use of melatonin implants alone should be recommended.