Raw milk composition of Malian Zebu cows (Bos indicus) raised under traditional system

Milk from Malian Zebu cows was analysed during the dry and hot season (March-June) in order to assess its composition and the components variation according to the presence of subclinical mastitis and supplementary feeding. The Zebu cow milk (n=30) was composed of 8 g/kg ash, 43 g/kg fat, 48 g/kg lactosemonohydrate, 37 g/kg proteins and 134 g/kg total solids. One-third of the cows tested positive to subclinical mastitis (white blood cell count >350,000/mL). Milk components were significantly affected by the somatic cell count (decrease of lactosemonohydrate, increase of fat and total solids P<0.01). Supplementation of the diet of Zebu cows with low quantity of pasture straw significantly and positively affected milk composition. The fatty acids were composed of a high proportion of polyunsaturated, long-chain fatty acids (oleic acid). This indicates that Zebu cows at this period of the year mobilize body fat for milk production because of the energy deficit in their diet. Lack of supplementary feeding of the Zebu cows and subclinical mastitis appeared to be main constraints in the extensive livestock system in Mali.