Identification of estrogen levels in dairy cows based on MUN levels and pregnancy rates

This study aimed to determine the effect of Milk Urea Nitrogen (MUN) levels as an indicator of protein intake to estrogen levels and pregnancy status in dairy cows. Eighteen productive heifers from wagir district, Malang were collected out from criteria. Thus, they were groups based on MUN levels and reproductive status. Feeding is done in the same pattern. Blood drawing for estrogen level were analized by Enzyme Linked Immunosorbent Assay (ELISA). Milk extraction for analysis of urea levels using the Barthelot method. Pregnancy examinations were carried out three months after Insemination. Data analysis were processed using SPSS (Statistical Package for the Social Sciences) for Windows programs. The results showed that non-pregnant cow had MUN levels from 16-28 mg/dL and high estrogen levels at time of estrus were the same as estrogen levels in pregnant cow. It can be concluded that the same feed pattern different produces MUN levels, estrogen and pregnancy status, depending on the efficiency of nitrogen utilization in the body and physiological health of individual dairy cows.