The effect of feeding level during lactation period on flushing in sheep

Nutrition has an important impact on the reproductive performance of ewes. Flushing defined as the practice of increasing level of nutrition in the pre-mating and mating period, is used with the objective of improving reproductive performance. However, it doesn?t always provide the expected results because of individual and environmental factors.The objective of the present study was to evaluate the effects of nutritional condition 4 to 6 months prior mating period and interaction with flushing on reproductive performance in sheep. Two nutritional level were used during lactation period started 6 months before mating in Karacabey Merino sheep. The different feding levels were used for the lactation period of nutrition as 100 % (KF-K) and 70 % (DF-D) according to NRC (2007). The ewes were assigned at random to two equal-sized groups during lactation period and then randomly divided into equal-sized subgroups as flushing (KF, DF) and non-flushing, three weeks before mating period.High level of nutrition during lactation resulted in an incresae of ovulation rate. However, the difference among the groups was not significant (P=0,296). It was determined that ovulation rate was 0,23 higher in the high nutritional level (KF-K) than low level (DF-D). Similarly, litter size was 0,15 more in KF-K groups than DF-D groups. However, the difference between high and low nutritional levels was not significantly (P=0,684).Flushing reduced fecundity in KF group but it did not affect in DF group. Besides the days of heat in DF group was shortened significantly (P=0,02).The effect of nutritional level during lactation on ovulation rate and lambing performance was not clear, due to the fact that the difference among the groups was not important. However, the effect of nutritional level 4 to 6 months before mating period has important potantial to effect reproductive performance in sheep.