Journal of Animal Science, Vol 70, Issue 6 1677-1681, Copyright © 1992 by American Society of Animal Science

JOURNAL ARTICLE

Subclinical mastitis in ewes and its effect on lamb performance

D. H. Keisler, M. L. Andrews and R. J. Moffatt
Department of Animal Science, University of Missouri, Columbia 65211.

Two studies were conducted to 1) assess the effectiveness of the California mastitis test (CMT) relative to direct microscopic somatic cell count (DMSCC) and(or) somatic cell count (SCC) procedures for detecting subclinical mastitis in ewes, 2) determine the incidence of subclinical mastitis based on repeated or single sample measures and organisms associated with the inflammation, and 3) assess the relationship between milk quality measures and lamb performance. The relationship between DMSCC and SCC scores was significant (P less than .01); 90% of the variation in DMSCC scores was accounted for by SCC scores. In contrast, CMT scores accounted for only 26% of the variation in DMSCC and 30 to 34% of the variation in SCC scores. Incidence of inflammation varied from 17 to 50% of ewes tested, depending on the study and the method of assessment. Staphylococcus species were cultured from 14/41 samples tested, with cultures of Streptococcus species (3/41) and Micrococcus species (1/41) also present. The effect of subclinical mastitis in ewes on lamb performance was minimal when assessed by regressing lamb weights on subclinical mastitis and milk quality scores. In conclusion, growth performance of lambs in a management system where they had access to supplemental feed was not influenced by the quality of milk produced by ewes, or by the degree of subclinical mastitic inflammation present when they suckled.

This article has been cited by other articles:

				J. Conington, G. Cao, A. Stott, and L. Bunger Breeding for resistance to mastitis in United Kingdom sheep, a review and economic appraisal Vet Rec., March 22, 2008; 162(12): 369 - 376. [Abstract] [Full Text] [PDF]