N. METODIEV1, E. RAICHEVA1 and I. RALCHEV2
1 Institute of Animal Science, Sheep Breeding Department, BG-2232 Kostinbrod, Bulgaria
2 University of Forestry, Faculty of Veterinary Medicine, Sofia, Bulgaria
METODIEV, N., E. RAICHEVA and I. RALCHEV, 2010. Influence of the salt-free – salt diet and the ram effect on main reproductive traits of ewes from Synthetic Population Bulgarian Milk. Bulg. J. Agric. Sci., 16: 788-793
The aim of this work was to study the effect of combined treatment of the salt free-salt diet and ram effect on main reproductive traits of ewes in different ages from the Synthetic Population Bulgarian Milk at the beginning of breeding season. The experiment was carried out with 107 ewes (in that number 26 maidens). The experimental ewes were at different age (between 1.5 and 6.0 years old) and respectively at different lactations (1-st, 2-nd, 3-rd and more), with middle weight 55-65 kg and body score estimation - 2.5-3.5. The ewes were divided in 4 groups according the range of lactation: I - maiden (1.5 years old); II-ewes at 1-st lactation; III - ewes at 2-nd lactation; IV- ewes at 3-rd and more lactation. Salt-free-salt diet was applied by the next scheme: first was saltfree diet, which continued 17 days. After that the ewes were put in salt conditions during 9 days (the salt lick were returned and in the concentrated forage was put salt (NaCl) in dose 20 g per ewe per day). The first day of salt diet coincided with the first day, in which ewes contacted with rams. Up to the beginning of breeding campaign, the rams were raised apart from ewes, in neighbor barn in the distance of 15 m. The ewes in estrus were detected by teasers once daily (1 teaser for 50 ewes) during 29 days. The ewes in estrus were inseminated according breeding plan artificially, vagino-cervically, with non-diluted semen. The parameters, that were studied, were: time of manifested estrus (at days) after the beginning of breeding campaign, fertility (at first estrus) and fecundity. 89.70% of the ewes were manifested estrus in the framework of 20 days as it was observed 2 surges – between day 1 and day 9 and between day 15 and day 20, after the beginning the breeding campaign. These results could be explained as a result of the ram effect and salt-free-salt diet and their synergic effect. The general fertility of the flock was 77. 00% and the fecundity was 127.27%.