Comparison of the Contents of Calcium, Magnesium and some Environmental Microorganisms in Cow Feed and Raw Milk Produced in Cameroon

A chemical and microbiological study was conducted on twelve dairy farms in the West Region of Cameroon (Central Africa) during the period 2019-2020. Two hundred and sixteen samples of drinking water, green fodder consumed by dairy cows and raw milk produced were analyzed. Calcium and Magnesium contents were assessed by volumetry and atomic absorption spectrometry methods. Lactobacilli, yeasts and molds were isolated on solid culture media by surface spreading techniques. The average Ca2+ concentrations were 42 mg/l, 1674 mg/kg and 1215 mg/l, in the drinking water, green fodder and milk produced respectively. That of Mg2+ was 26 mg/l, 1913 mg/kg and 160 mg/l respectively. The Ca2+ content of the raw milk produced was not significantly different (p>0.05) from that of the green fodder consumed by the cows. However, the drinking water had a significantly lower Ca2+ and Mg2+ content than the green fodder consumed and the raw milk produced (p0.05). Similarly, the yeasts and molds abundance dynamics in the drinking water of the cows were not significantly different from those in the milk produced (p>0.05). Practical Applications : The mineral content of milk depends mainly on the mineral concentration of the feed consumed by the cows. Green fodder and drinking water are potential sources of microorganisms that can have an impact on the microbiota of the raw milk produced. It is therefore essential to treat the water before the animals are drunk and to improve fodder production in the region.