Abstract
BACKGROUND: Smallholder dairy farming is the largest fresh milk producer in Indonesia. The success of dairy cattle production depends on feed protein, increased blood or milk urea, increased crude feed protein, and increased degradation of feed protein. AIM: This study aimed to determine the effect of concentrate intake given to Friesian Holstein dairy cows on community farms on blood urea nitrogen (BUN), estrogen, and insulin-like growth factor-1 (IGF-1) levels. METHODS: Gradually selecting the sample from 100, 50, and 21 dairy cows, we used the equality of variables as the control variable. Blood sampling was performed simultaneously on the day of artificial insemination (D0), the seventh (D+7), and D+22 (D+22) after artificial insemination. Pregnancy examination was performed using the rectal palpation technique three months after insemination. RESULTS: Milk production and BUN levels increased with increasing concentrate intake up to a certain limit. Estrogen levels based on BUN and pregnancy on D0 and D+7 were not significantly different (p > 0.05) between the groups. In contrast to the group of nonpregnant cows with low BUN, estrogen concentrations in pregnant cows with low BUN and nonpregnant cows with high BUN were lower on D+22. IGF-1 levels in pregnant cows were higher for D0, D+7, and D+22 at unbalanced IGF-1 levels in cows with BUN >18 or <18 mg/dl. CONCLUSION: This research is an effort to increase milk production by increasing concentrate intake and must pay attention to BUN level, which affects up level of IGF-1, services per conception, and calving interval levels.