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

摘要

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 10~(th) and 40~(th) day for analysis of somatic cell counts (SCC), sodium content, pH and electrical conductivity. The farm owners were provided with Masted 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 Masted strip test, which was confirmed by SCC in milk (2.97 x lO~s 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 x lO~s 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 in62 animals was within the normal range (0.75-2.50 x lO~s 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.