Some bacteriological and immunological studies on subclinical mastitis in cows

Abstract

Increase of incidence of SCM due to environmental pathogens (86.04 % of SCM samples) in comparison with the contagious pathogens (S. aureus + S. agalactiae 13.78% SCM samples). Lower incidence of S. aureus (8.73% in SCM samples) and S. agalactiae (5.41%) was recorded in relative to other major pathogens. Incidence of subclinical mastitis in small, medium non-organized farms (69% of animals and 49.4% of quarters) was higher than it in large, organized and intensive farm group (57.6% of animals and 38.8% of quarters). S. dysgalactiae was the most recovered pathogen (13.66% of examined quarters and 26.85 % of isolates). Increase of incidence of CNS (15.33% of examined quarters) which were S. epidermidis and S. saprophyticus in comparison with S. aureus (3.6% of examined quarters). Higher incidence of SCM with E. coli (7.35% of examined quarters) as major mastitis pathogens in relative to the other major pathogens, S. aureus and S. agalactiae (3.6% and 2.31% of examined quarters respectively). Mean SCC in samples of the large, organized and intensive farm group was higher (548000 cell/ml) than in small, medium non-organized farms (455000 cell/ml). In large organized intensive farm group, the higher SCC were associated with E. coli (607000 cell/ml milk) and S. aureus (599000 cell/ml milk) infections which are two major pathogens in comparison with S. saprophyticus (519000 cell/ml milk), S. agalactiae (445000 cell/ml) and S. epidermidis (279000 cell/ml). While in small non-organized farm group, the higher values were E. coli (464000 cell/mi) and S. epidermidis (563000 cell/ml). In large organized farm group, Geometric means of LDH, GOT and ALP were higher (419, 158 and 488 µL/ml respectively) than in small owners and small farm group (359, 150 and 446 µL/ml respectively). LDH geometric means in samples of the large organized intensive farm group were higher than the means in small non-organized farm group for all recovered pathogens in the study.