INCREASE IN THE FERTILITY RATE OF EWES BY FOCUSED FLUSHING FROM 9TH TO 14TH DAY OF THE ESTRUS CYCLE, SYNCHRONIZED BY THE RAM EFFECT.

Krum Nedelkov, Nikolay Todorov, Boyko Georgiev, Aleksandar Atanasov

Abstract: The purpose of this study was to determine the possibility for increasing the fertility of Middle Balkan Mountain Sheep (Srednostaroplaninska ovza) by 6 days (acute) flushing with rich in energy and protein feed in the second half of the luteal phase of the estrous cycle. An experiment has been carried out by a flock with 213 ewes at an average body condition score (BCS) 2.67 (1 emaciated, 5 obese) divided in two groups for the period of flushing. In one of the groups flushing has not been applied used and this group served as a control. The second group received 500 g per capita daily rich in crude fat (15.6% of dry matter) sunflower expeller from 9th to 14th day of the expected estrous cycle. Synchronization of estrus has been performed by the ram effect and flushing coincided with 11th to 16th days from the introduction of equipped with protective aprons rams in the flock. The ewes which came in estrus from 18th to 26th day after introduction of rams in the flock, i.e. during the expected ram effect period had 13,5% more ovulating ova, accounted by the number of formed corpora lutes and twins were 16.3% more than in the control group of ewes which has not been acute fed. The ewes which didn’t come in estrus immediately after flushing had practically the same percentage of twins with control ewes. It was established a tendency for lower levels of estradiol-17β and progesterone in the blood plasma of acute fed ewes during the follicular phase of the estrus cycle. To the ram effect reacted significantly higher percentage of ewes with BCS over 2.5, compared with the poor ewes with BCS under 2.5. The results of the experiment allow concluding that synchronization of estrus by the
ram effect and acute flushing with sunflower expeller can increase the fertility of ewes.

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Date published: 2023-03-06