Iraqi Journal of Veterinary Sciences

Abstract

The aim of this study was to examine the changes that occur in milk constituents of Awassi sheep due to experimentally infection with Staphylococcus aureus which was isolated from milk sample of clinically infected ewe with mastitis. A total of 240 samples of normal and infected milk from both left and right halves of udder of 6 Awassi sheep before and after induced infection were collected from tested healthy ewes. Milk samples were collected through 10 days before and after infection with Staph. aureus. Experimental inoculums with Staph. aureus was done with effective dose 150 Colony Forming Unit. Milk constituents were evaluated with Ultrasonic Milk Analyzer (Ekomilk) before and after induction of mastitis to all milk samples to determine Fat, Proteins, Solids Non-Fat, Density, Lactose and pH. The results also showed that there was a significant decrease (P<0.05) in the percentages of Fat, Proteins, Solids Non-Fat and Lactose, but there is a significant increase (P<0.05) in pH. The right half of the udder after experimental infection of bacteria also showed the same significant results such as those in the left mastitic half due to transmission of the infection between the two halves, after inoculation of the left half.