Bovine Mastitis Pathogens in New York and Pennsylvania: Prevalence and Effects on Somatic Cell Count and Milk Production

Abstract

Milk samples were collected from 108,312 dairy cows during 1601 farm visits made between January 1991 and June 1995. The herd visits were made by personnel from the Central Laboratory of the Quality Milk Promotion Services at Cornell University (Ithaca, NY) to farms located in central New York and northern Pennsylvania. Dairy Herd Improvement Association records were available for 32,978 cows in 327 herds. Intramammary infections, as defined by positive milk cultures, were present in 48.5% of all cows and in 36.3% of cows in herds enrolled in the Dairy Herd Improvement Association. Over 75% of the intramammary infections were caused by Streptococcus agalactiae, Streptococcus spp. other than Strep. agalactiae, Staphylococcus aureus, and coagulase-negative staphylococci. Mean days in milk at the time of diagnosis, linear score of the somatic cell count, cost of milk loss per lactation, and milk production effects were calculated for 24 etiologic agents of bovine mastitis.

Sensitivity and specificity of a hand-held milk electrical conductivity meter compared to the California mastitis test for mastitis in dairy cattle

“…Coagulase-negative staphylococci were the most frequently isolated bacteria in milk samples from both lactating and dry cows during 2000 to 2007, followed by Staphylococcus aureus and Streptococcus agalactiae (Petzer et al, 2009). Staphylococcus aureus can be considered the most important mastitis pathogen in South Africa because of the economic impact (Wilson et al, 1997) and potential for chronic infections and treatment failures.…”

Species identification of coagulase-negative staphylococci: Genotyping is superior to phenotyping

“…Increased SCC is generally associated with decreased milk 55 production (Seegers et al, 2003) but subclinical intramammary infections by CNS have 56 been associated with increased milk production (Wilson et al, 1997). By contrast, clinical 57 CNS mastitis was linked to decreased milk production (Gröhn et al, 2004) and increased 58 risk of culling (Gröhn et al, 2005).…”

Isolation and identification of main mastitis pathogens in Mexico

“…It ranges from 3.0 -3.5% in Finland and Germany and from 34.2%  38.5% in Zimbabwe and Australia, (Daniel et al, 1982;Myllys et al, 1998;Kloppert et al, 1999;Kudinha and Simango, 2002;Milne et al, 2002). In other countries such as USA, Ethiopia, and Brasil the S. aureus was detected in 7.6%, 9.1% and 9.5%, respectively (Bishi et al 1988, Wilson et al 1997, Benites et al, 2002. The aim of the present work is to monitor the actual role of different pathogens in the induction of mastitis in Jalisco State, west Mexico and to detect the incidence of subclinical mastitis in relation to clinical cases.…”