PREVALENCE OF SUB-CLINICAL MASTITIS IN COWS IN RANGPUR DISTRICT

Abstract

Sub-clinical Mastitis is a zoonotic standpoint important disease of the mammary gland caused by mainly bacterial infection and the most common and costly health disorder of dairy cows. It has a negative economic impact on dairy farms in terms of disordered milk, lost of production, reduced milk quality and treatment costs. It is responsible for greater loss to the dairy industry and the annual economic losses due to mastitis. A cross-sectional study was carried out on a total of 150 lactating dairy cows at (small holder dairy farm and large scale farm system) urban and semi urban area of Rangpur district to determine the prevalence of Subclinical Mastitis (SCM) using California Mastitis Test (CMT), White Side Test (WST) and Strip Cup Test during the period from January to December, 2017 The overall prevalence of SCM was 38.66%. Prevalence of sub-clinical mastitis is significantly higher in cross breed (53.8%) than local breed (27.1%). Of all cows tested, cows showed positive reaction for SCM by CMT, WST and Strip Cup Test were 30%, 28.57% and 22.22% respectively in local breed and in cross breed 59.09 %, 57.14 %, and 50 % respectively. CMT showed better performance in detecting SCM (30% in local breed and 59.09 % in cross breed) among three indirect tests used. The prevalence of SCM was significantly (p<0.05) higher (45.45% in local breed and 70% in cross breed.) in older aged group cows (9-12 years) than young aged group (3-5 years) cow. The prevalence of subclinical mastitis was increased with parity of cows. Cows with 5th and 4th parity had higher SCM than others parity in local breed and cross breed respectively. The prevalence of SCM was significantly (p<0.05) higher (53.85%) in cows yielding 3-5 of milk than lower milk yielding cows in local breed. The prevalence of SCM was significantly (p<0.05) higher (75 %) in cows yielding >5-10L of milk than lower milk yielding cows in cross breed. The prevalence of SCM was highest in late lactation (43.75% in local breed and 63.63% in cross breed) followed by mid lactation (29.03% in local breed and 45.83% in cross breed) and then early lactation (18.42% in local breed and 45.83% in cross breed).