Control of Mastitis through dry cow therapy: A review

Introduction Mastitis is one of the most economically important diseases of milch animals and also causes the changes in glandular tissues affecting quality and quantity of milk [1]. Mastitis continues to be the most costly disease of dairy animals. Field surveys of major livestock diseases in Pakistan have ranked mastitis as number one disease of dairy animals [2,3]. In Nili-Ravi buffaloes, mastitis shortens lactation period of each animal by 57 days on an average and reduces 438 kg of milk per lactation [2]. Statistics of current losses in Pakistan due to mastitis are not yet available, but in Punjab alone, the total losses caused by clinical mastitis amount to Rs. 240M per year [3,4]. These occur through discarded milk, reduction in milk yield, premature culling of animals and replacements. Dipping of teat and dry period therapy are not so far being carried out in Pakistan [5]. Mastitis occurs in two farms i.e. clinical and subclinical. Clinical mastitis is defined as udder inflammation characterized by visible abnormalities in the milk or udder or both. Severity of clinical cases can be described as mild, moderate, or severe. The incidence of clinical mastitis in buffalo ranges from 8 to 40% [6]. Subclinical mastitis show no macroscopic evidence of inflammation, but examination of the milk reveals udder infection, increased cell count and also alteration in the chemical properties of the milk. The quarter wise prevalence of intramammary infection in buffalo was 66%. Since the mammary gland is highly susceptible to infection during the periparturent period, the incidence was highest during the 30 days after calving [7]. Mastitis can be prevented when an effective control program is adopted. Dry period therapy is an essential part of this control program. To be fully effective dry period therapy should be used in conjunction with recommended practices for environmental control, equipment management and milking management [8, 9].