Influence of litter size on histochemical picture of ewe oviduct during the puerperal period

The study focuses on the activity of alkaline phosphatase, acidic phosphatase and non-specific esterase in the epithelial cells of the oviducts of puerperal ewes with a single lamb (n = 24) and two lambs (n = 24). The experimental animals had the ampullar sections of the oviducts removed on days 7, 17, 25 and 35 postpartum. The results indicated an upward trend in the activity of the investigated enzymes in both groups of animals from day 7 to 35 of the puerperal period. However, the increase in enzyme activity in the ewes with twins was slower in comparison with the ewes with a singleton, which was significantly manifested by lower alkaline phosphatase activity (5.8 ± 0.4 vs 4.3 ± 0.4; P < 0.01), acidic phosphatase activity (11.5 ± 0.3 vs 7.2 ± 0.4; P < 0.05) and non- -specific esterase activity (11.3 ± 0.4 vs 8.7 ± 0.4; P < 0.05) on day 25 postpartum. These differences between the groups persisted until the completion of the experiment with alkaline phosphatase activity (7.1 ± 0.7 vs 5.7 ± 0.3; P < 0.05), acidic phosphatase activity (14.4 ± 0.4 vs 8.6 ± 0.3; P < 0.001) and non-specific esterase activity (11.6 ± 0.5 vs 9.5 ± 0.4; P < 0.01) on day 35 postpartum. The results indicate that the retardation of functional changes in the ewes with twins reveals the prolongation of time essential for the completion of regenerative processes in the epithelium of the oviducts. The discussion deals with the possible utilization of these facts in relation to optimizing out of season breeding in sheep.