SYNCHRONIZING FERTILIZATION IN BULGARIAN MILK SHEEP POPULATION BY THE RAM EFFECT

Nikolay Todorov, Krum Nedelkov, Andrea Kolev, Todor Marinkov

Abstract: The purpose of the studies is to determine the extent of response of Synthetic Population Bulgarian Milk Sheep to the “ram effect” and the possibility of non-hormonal synchronization of fertilization. An experiment has been carried out for four years with three flocks in one farm. Ewes were below average body condition (BCS of 2,7 in 5 grade system) and artificial insemination, starting in different years between 25 July and 10 August, which coincides with the transition to the natural breeding season. Rams were isolated from sheep for 8 months. Ram-teasers, equipped with aprons were placed into the flocks for the detection of estrus in ewes during artificial insemination (AI), which lasted 30-38 days and then are placed intact rams for mating that have remained into the flocks by the end of December. A total of 2084 sheep from three flocks for four years were lambed 1771 (85%) ewes. From the first until 15th day after contact with the rams were inseminated 9.2% of all ewes or 10.8% of all lambed ewes. During the period when it is expected estrus as a result of the “ram effect” i.e. from 16 to 28 days of placing rams into the flocks come in estrus and was AI 45.9% of all ewes in the flocks or 54% of all lambed ewes. In conclusion, the ewes from the Synthetic Population Bulgarian Milk Sheep react to a significant degree to the “ram effect” as a result of which more than a half (54%) synchronously lambing within 13 days. This natural, easy and inexpensive method for partial synchronization deserves to be used on farms.

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Date published: 2023-01-25