A Study on Reducing the Incidence of Sub-Clinical Mastitis in Dairy Cows by Feeding a Vitamins and Minerals based Strategic Feed Supplement

Abstract

One hundred twelve high yielding (>20kg/animal/day) crossbred cows having a history of clinical and sub-clinical mastitis in previous lactation were selected from 24 farms in Mohali and Ropar districts of Punjab. Thirty-three cows from eight farms served as control, and remaining were fed daily 10 g supplement per animal, containing chelated copper, zinc, chromium, vitamins E and A along with iodine for four weeks before calving. After calving, milk samples were collected on 10th and 40th day for analysis of somatic cell counts (SCC), sodium content, pH and electrical conductivity. The farm owners were provided with Mastect strips for routine check up for sub-clinical mastitis. Out of 79 experimental cows, only 17 showed positive signs for sub-clinical and clinical mastitis with Mastect strip test, which was confirmed by SCC in milk (2.97 x105 cells/ml milk). However, out of thirty three, twenty nine animals in control group were affected by sub-clinical mastitis as indicated by SCC (3.19 x105 cells/ml milk), which was later aggravated to clinical mastitis. The pH, electrical conductivity, SCC and sodium content in milk were higher (P<0.01) in animals affected by sub-clinical mastitis than the normal animals. In experimental group, SCC in 62 animals was within the normal range (0.75-2.50 x105 cells/ml milk) and no signs of sub-clinical or clinical mastitis were observed. The inference could be drawn that feeding a vitamins and chelated minerals based strategic feed supplement for four weeks prior to calving can reduce the incidence of sub-clinical and clinical mastitis significantly in dairy cows under farm conditions.