LEVELS OF ARACHIDONIC-ACID IN LIVER, OVAR IES AND UTERUS OF COWS FROMHERDS WITH GOOD AND LOW FERTILITY

Research was carried out at two localities ecologically different, i.e . in the ''relatively'' clean region of Klatovy, designed according to the standards of the Czech Ministry of Environment as a region with a bove-average quality environment and in the considerably affected regi on of Prague-East, designed as a region with below-average quality env ironment. The first group included 33 cows from herds with good fertil ity (average conception rate after 1st insemination 61,5 and service p eriod 88 days) and the dairy cows were eliminated for reasons differen t as reproductive disorders (Klatovy), in the second group all 18 cows were eliminated because of reproductive disorders (Prague-East) and t hey were from the herds with much lower fertility (average conception rate after 1 st insemination 46,9 % and service period 107 days). Samp les of fiver, uterus and ovarian tissues of the cows were processed ac cording to the method after Jary et al. (1987), analysed on the gas ch romatograph Varian - Aerogramm 2100. The data obtained were processed on a computer IBM PC - AT with a numeric co-processor, and the program me Quatro Pro, version 2.0 was used. Differences in average amounts me asured in both regions are objectively characterized in Figs. 1, 2 (wi th marked scaterings) and correspond to the amount given in Tab. I. As regards the saturated acid, stearic acid and oleic acid, no remarkabl e differences were found according to the localities (Klatovy and Prag ue), with the exception of the average contents of those acids in uter ine horns. In that case the region of Klatovy is dominating. When the functions of reproductive organs are to be characterized, the interest was mainly focused on the differences in the amount of linoleic acid (Fig. 1) and arachidonic acid (Fig. 2) in the uterus tissue and on the presence of corpus luteum, and also on their presence in liver. In al l cases (except the linoleic acid contents in ovaries), the lower conc entration of these acids (18:2 a 20:4) was found in the total amount o f fatty acids isolated from these organs in samples taken from the reg ion of Klatovy, i.e. in cows with good fertility. The results describe d are similar to those concerning a group of twelve cows with pasture and without it. The observation was concentrated on the difference in the arachidonic acid contents in the liver of the housed cattle and th e cattle with pasture at the same locality in the surroundings Klatovy . The data in 12 heifers show smaller average amounts in cows with pas ture then without it. Disturbances of reproduction can be caused by ma ny reasons, among other things by the bad environment, by worsened qua lity of water and fodder, in view of chronical intoxications with heav y metals, mycotoxins, PCB and other polychlorinated hydrocarbons, as w e exhibited in our older studies. Probably this negative influence is strong enough to evoke the response of the immnunity system in the org anism, metabolism of which starts to synthetize higher concentrations of arachidonic acid. By the effect of lipoxygenase, the metabolism of excessive arachidonic acid can be changed for the benefit of leukotrie nes. This may result in higher sensitiveness to allergens, lowered imm unity, bring about various inflammations of the uterus, which were con firmed in cows from the region of Prague-East. Furthermore, cyclooxyge nase may affect higher concentrations of prostaglandin F2alpha, which may cause luteolyse in an unsuitable period (more than 70% of the cycl es in cows from the group Prague-East were prolonged), but it is also known that higher concentrations of PGF2alpha may retard or even block the motility of spermatozoa. It is a well-known fact from practice th at grazing heifers and cows have better condition, health and reproduc tion. This is in compliance with the results of this study showing tha t both cows with good fertility bred in better environment and cows wi th pasture exhibited the lower arachidonic acid content in their liver and reproductive organs.