Med. Weter. 82 (1), 27-32, 2026
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| SEDDIK KEBBAL, ISMAIL GHARBI, RÉDHA BELALA, NADIA HEZIL, AMINA SAMIA DECHICHA, DJAMILA BAAZIZE-AMMI, KARIM RAHAL, DJAMEL GUETARNI, NORA MIMOUNE |
| Performance of a colorimetric method for milk urea evaluation in dairy farms: the screening study |
| The aim of this study, conducted in the Blida region in north-central Algeria was to evaluate a colorimetric method (CM) for measuring milk urea concentration and to assess its relevance as an indicator of dietary balance, thus addressing the lack of nutritional management tools for dairy cows in Algeria. The approach was first to validate the colorimetric method (CM) by testing 50 milk samples and comparing the results with those obtained by a reference enzymatic method (RM). Then, we analyzed 52 Holstein cow milk samples to correlate urea concentration with milk yield and protein content (PC). The results confirmed a high reliability of CM for on-farm monitoring, demonstrating an excellent correlation with the reference method (r = 0.8589; p < 0.001). The herd analysis revealed an optimal average urea concentration (236.92 mg/L). A positive and statistically significant correlation was found between urea and protein content (r = 0.42; p = 0.03), while no association was observed with milk yield (r = 0.14; p = 0.31). Cross-analysis of urea-protein profiles showed that 61.5% of the animals had a nutritionally balanced diet, while 38.5% exhibited imbalances. The predominant issue, affecting 21.15% of the cows, was an excess of fermentable nitrogen in the diet, revealed by elevated urea levels (> 300 mg/L) associated with normal protein content. This profile indicates an oversupply of degradable protein, which may contribute to metabolic stress. In conclusion, the colorimetric method is a reliable and relevant monitoring tool. However, the findings highlight the need to combine it with other indicators to obtain a comprehensive and accurate assessment of dietary balance. |
| Keywords: milk, cow, urea, protein, nutritional monitoring, colorimetric method. |