Evaluation of morphological lesions in selected internal organs in lambs of Kamieniecka, Pomorska and Polish Blackheaded Mutton sheep and their crossbreeds.

Investigations were carried out on 40 rams aged 50 days (n = 8), Kamieniecka (K), Pomorska (P) and Polish Blackheaded Mutton (PBM) breeds and their crossbreeds (K x PBM, P x PBM). Microscopic evaluation of the liver, kidneys, spleen and heart muscle in the rams as well as ultrastructural analyses of their liver and semitendinous muscle showed that retrogressive lesions, circulation disturbances, inflammation and progressive changes occurred respectively: frequently, occasionally, rarely. Internal organs, particularly liver and kidneys, of crossbred rams (K x PBM and P x PBM) were almost two times more affected with morphological lesions than purebred lambs (K and P). However, in the semitendinous muscle these differences were more vivid in the ultrastructural analysis than in the histopathological or macroscopic observations. Results suggest that breed growth-rate differences have effects on the pathomorphological pattern of the liver and kidneys in lambs. On the bases of this evaluation, it can also be emphasised that young PBM rams are less susceptible to morphological lesions than the K and P breeds.

The influence of the reproductive cycle on levels of some metabolism indices in ewes.

Investigations were performed in 14 ewes of the Polish Merino race, undergoing the second reproductive cycle. Fundamental indices of the protein and energy metabolism, levels of Ca, P, Mg, Cu, Fe and beta-carotene as well as vitamins A, E and C in the blood plasma and serum were determined. The analyses were carried out during the following periods of the reproductive cycle: 3 weeks before mating, the early and late pregnancy, the culmination and close of lactation. The levels of metabolism indices, especially those of the protein and energy metabolism, were found to vary during the studied periods of the reproductive cycle. In all the periods, low levels (during lactation a deficiency) of Ca and Mg and a distinct deficiency of vitamin C were detected. It seems therefore, necessary to work out the reference values for particular periods of the reproductive cycle.