Interkorelasi antara persentase konsentrat, kadar urea nitrogen susu dan beberapa variabel sapi perah Friesian Holstein

The purpose of this study was to identify the correlation among the percentage of feed concentrate, milk urea nitrogen (MUN), milk production, services per conception (S/C), calving interval (CI), and days open (DO) of Holstein Friesian cows on smallholder farms. Twenty four, 4-6 year old, non-pregnant, lactating cows, with body condition score (BCS) 5-7, having given birth 2-5 times were recorded their daily milk production, S/C, CI, DO, and the percentage of concentrate in feed given. Milk samples were collected to measure MUN. The correlation calculation among the six variables resulted 15 correlation values, ten of which were not significantly different (p >0.05), including the correlation between the percentage of concentrate and milk production on MUN. The other five correlation values were significantly different (p <0.05). The increase in concentrate intake was moderately correlated (r = 0.52), affecting 27.04% of the increase in milk production, and weakly correlated (r = 0.39), affecting 15.21% of the increase in S/C. The increase in milk production had a very strong correlation (r = 0.82), affecting 67.24% of the increase in S/C. The increase in S/C had a strong correlation (r = 0.61), affecting 37.21% of the increase in CI. The increase in CI was also affected 38.44% by the increase in milk production with a strong correlation (r = 0.62). It could be concluded that dairy cows with higher feed concentrate intake would be followed by an increase in milk production, but had a negative effect on reproduction in the form of increased S/C and CI.