Interrelationships between somatic cell counts, lactation stage and lactation number and their influence on plasmin activity and protein fraction distribution in dromedary (Camelus dromedaries) and cow milks

In the present study, the relationship between milk somatic cell counts (SCC), nitrogen fractions, individual casein percentage distribution, plasmin-plasminogen activities and proteolysis, and the influence of lactation stage and lactation number in dromedary and cow milks were compared. Dromedary milk appeared to contain a lower amount of total and pH 4.6-soluble nitrogen than cow milk. The major protein components in milks were caseins, which accounted for ∼70% of total proteins for both species, - and s1-being the predominant caseins in both milk kinds. In dromedary milk, -casein increased with lactation number but decreased as SCC increased. Total protein, s2-casein and SCC decreased during lactation in dromedary milk. The dromedary is characterized by a relatively low content of -casein. Plasmin plus plasminogen activity is higher in cow milk compared to dromedary milk. The plasmin activity increased as SCC increased in cow milk but not in dromedary milk. Crown Copyright © 2012 Published by Elsevier B.V. All rights reserved.