Levels of Arachidonic-Acid in Liver, Ovaries and Uterus of Cows from Herds with Good and Low Fertility

Veterinarni Medicina 38, 1993, 531-538

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 above-average quality environment and in the considerably affected region of Prague-East, designed as a region with below-average quality environment. The first group included 33 cows from herds with good fertility (average conception rate after 1st insemination 61,5 and service period 88 days) and the dairy cows were eliminated for reasons different as reproductive disorders (Klatovy), in the second group all 18 cows were eliminated because of reproductive disorders (Prague-East) and they were from the herds with much lower fertility (average conception rate after 1 st insemination 46,9 % and service period 107 days). Samples of fiver, uterus and ovarian tissues of the cows were processed according to the method after Jary et al. (1987), analysed on the gas chromatograph Varian - Aerogramm 2100. The data obtained were processed on a computer IBM PC - AT with a numeric co-processor, and the programme Quatro Pro, version 2.0 was used. Differences in average amounts measured in both regions are objectively characterized in Figs. 1, 2 (with marked scaterings) and correspond to the amount given in Tab. I. As regards the saturated acid, stearic acid and oleic acid, no remarkable differences were found according to the localities (Klatovy and Prague), with the exception of the average contents of those acids in uterine 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 all cases (except the linoleic acid contents in ovaries), the lower concentration of these acids (18:2 a 20:4) was found in the total amount of fatty acids isolated from these organs in samples taken from the region of Klatovy, i.e. in cows with good fertility. The results described 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 the cattle with pasture at the same locality in the surroundings Klatovy. The data in 12 heifers show smaller average amounts in cows with pasture then without it. Disturbances of reproduction can be caused by many reasons, among other things by the bad environment, by worsened quality of water and fodder, in view of chronical intoxications with heavy metals, mycotoxins, PCB and other polychlorinated hydrocarbons, as we exhibited in our older studies. Probably this negative influence is strong enough to evoke the response of the immnunity system in the organism, 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 leukotrienes. This may result in higher sensitiveness to allergens, lowered immunity, bring about various inflammations of the uterus, which were confirmed in cows from the region of Prague-East. Furthermore, cyclooxygenase may affect higher concentrations of prostaglandin F2alpha, which may cause luteolyse in an unsuitable period (more than 70% of the cycles 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 that grazing heifers and cows have better condition, health and reproduction. This is in compliance with the results of this study showing that both cows with good fertility bred in better environment and cows with pasture exhibited the lower arachidonic acid content in their liver and reproductive organs

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