Investigation of Relationship among Dietary Fatty Acids, Milk Urea Nitrogen and Fertility Problems in Dairy Cattle Farms

The aim of this study was demonstrated the relationship between the nutritional variables of ration and the fertilityparameters in the postpartum period in dairy cattle farms. All dairy cattle farms used in the present study had fertilityproblems (calving range ≥14 months and artificial insemination number ≥1.8). Ration and milk samples were taken fromselected dairy cattle farms. Fertility records from herd registration systems were examined. In the study, milk urea nitrogen(MUN) levels of the milk samples were different between the farms; the lowest was 7.37 mg/dL, and the highest was 32.92mg/dL (P<0.001). The artificial insemination number was negatively correlated with the monounsaturated fatty acid (MUFA)concentration of total mix ration (TMR) (r=-0.502; P<0.01). The rations at the beginning of lactation included average 31.09%of w-6 fatty acids, 1.99% of w-3 fatty acids, and 2.95% of w-9 fatty acids. The MUN concentration of milk was negativelycorrelated with long-chain fatty acids (LCFA) and linoleic acid concentrations of TMR (P<0.05). As a result, it can be said thatthe easy soluble carbohydrates, crude protein, oleic acid, w-3 and w-6 fatty acids and energy levels that may be related tofertility in dairy cattle should be well adjusted. It was concluded that targeted milk production and fertility could be achievedby feeding as many nutrients as genetic capacity allowed.