Phagocytic activity and the phagocytic index of milk PMN’s as a marker for diagnosis and monitoring of the therapeutic and prophylactic efficacy of antioxidant formulation in bovine mastitis

Abstract

A clinical study was undertaken on bovine mastitis in the Kashmir valley to study the relationship between Phagocytic activity (PA) and the phagocytic index (PI) of milk neutrophils (PMN’s) and bovine mastitis. The PA and PI of milk PMN’s were assessed in mastitic animals and compared with normal, healthy, lactating animals. A significant decrease was found in the values of the PA and PI of milk neutrophils in clinical cases of mastitis as compared to the healthy control group. The utility of anti-oxidants in clinical management of mastitis was measured through the response to treatment with trace minerals such as Cu, Zn, Mn and Se in addition to conventional antibiotic therapy. Two groups of mastitic animals received two therapeutic regimens. Group I animals received antibiotics (Enrofloxacin 6.6 mg/kg BID for 5 days) and a self-formulated trace mineral anti-oxidant mixture at therapeutic doses for 7 days, while Group II animals only received the antibiotic (at the same dose rate and frequency). Therapeutic regimen I proved more efficacious than the therapeutic regimen II in the treatment of clinical mastitis, as evidenced by higher recovery rates, a lower number of mean days required for recovery, and higher PA and PI of the milk PMN’s on day 10 post treatment. For prophylactic studies, 24 healthy lactating cows were divided into two groups of 12 animals each. One group was supplemented with a self-formulated trace mineral anti-oxidant mixture at prophylactic doses for 30 days, which resulted in a significant improvement in udder health status in terms of the SCC, PA and PI of milk PMN’s. Supplementation with the antioxidant formulation played a significant role in early recovery and prophylaxis of bovine mastitis. Assessment of PA and PI of milk PMN’s could be utilised as an effective tool for diagnosing susceptibility to the occurrence of mastitis, as well as monitoring the therapeutic efficacy of different treatment regimes.