EVALUATION OF SOME MACRO AND MICRO MINERALS OF FEEDS, SERUM, AND MILK AT HARAMAYA UNIVERSITY DAIRY FARM

A study conducted at Haramaya University dairy farm aimed to evaluate the levels of macro and micro minerals in the feed, serum, and milk of lactating dairy cows. The 6 feed samples were collected from dairy farms and 22 milk and blood samples from cows selected based on parity (three to four) and stages of lactation (4 post-partum, 6 early, 6 mid, and 6 late). The analysis included measuring Calcium (Ca), Phosphorus (P), Potassium (K), Sodium (N), Magnesium (Mg), Zinc (Zn), and Iron (Fe) in the milk and feed samples, and Ca, P, K, and Na in the serum samples. Various instruments such as Ultraviolet–visible spectrophotometer (for P), flame emission photometer (for Na and K), atomic absorption spectrometer (for Ca, Mg, Zn, and Fe), and a Cobas 311 (for serum Ca, P, K, and Na) were used for analysis. Data were analyzed using the General Linear Model (GLM) procedure of SAS version 9.4, and correlations between minerals in milk and serum were assessed using bivariate analysis. The overall concentrations of Ca, P, K, Na, Mg, Zn, and Fe in the feed samples were 0.15±0.03%, 0.2±0.04%, 0.6±0.025%, 0.25±0.012%, 0.27±0.01%, 9.2±1.2ppm, and 20.7±2.1ppm, respectively. In the milk samples, the overall concentrations of Ca, P, Na, K, Mg, Zn, and Fe were 76±0.02g/L, 0.46±0.02g/L, 0.5±0.02g/L, 1±0.02g/L, 0.15±0.008g/L, 3.33±0.28mg/L, and 13±0.3mg/L, respectively. The serum samples had overall concentrations of Ca, P, Na, and K as 3.41±0.07mg/dl, 4.43±0.26mg/dl, 124.6±4.6mmol/L, and 3.7±0.14mmol/L, respectively. Significant concentration differences (p