California Mastitis Test and Somatic Cell Counts as Indicators of Intramammary Infection in Dairy Goat in Kenya.

Abstract

Intramammary Infections in goats is an important and costly disease.  Subclinical Mastitis (SCM) constitutes the greater part of this problem.  Several methods are available for diagnosis of SCM.

The objective of this study was to evaluate the application of somatic cells measured indirectly by CMT, and directly by SCC – as possible markers for IMI in dairy goat mastitis.

CMT was performed randomly on 138 udder halves at milking site, while in the laboratory SCC was conducted on 239 samples. Bacterial culture was done on 250 samples.

The results of CMT showed that 12.3% of samples were negative, while 30.4%, 23.2% and 34.1% recorded +ve 1, 2, 3 respectively. The SCC ranged between 248 x 10⁶ and 1693 x 10⁶, with a mean of 869 x 10⁶. The key bacterial isolates were Staph. aureus 58%, E.coli 40.5%. A statistical analysis to determine the strength and direction of association between CMT & SCC indicated a positive but not statistically significant correlation. ANOVA across the key bacterial isolates showed all bacteria falling between CMT mean scores of 2 and 3. The SCC showed that the key bacteria isolated had mean scores 86169 x 10⁶ for E. coli and 8810 x 10⁶ for Staph. aureus.

There is a consensus amongst researchers in this area that a CMT scores of 2 and above are indicative of infection in goat milk. The results of this study on Staph. aureus and E. coli, and the fact that 73.9% of E. coli and 68.5% of Staph. aureus fall in the range 500,000 and 1 million cells, SCC was an accurate determinant of infection.

Key words: Somatic cell counts, goat mastitis.