Interrelationships between somatic cell counts, electrical conductivity, bacteria counts, percent fat and protein in goat milk

Abstract

Six French-Alpine and six Anglo-Nubian does in mid-lactation at 150–180 days of milking, were randomly selected from the University herds, and morning and afternoon milk samples from each doe were tested for interrelationships between levels of somatic cell counts (SCC), electrical conductivity (EC), standard plate counts (total bacteria counts; SPC), staphylococcus counts (STC), coliform counts (CFC), percent fat and protein in goat milk. Mean cell counts of the combined breed data for SCC, SPC, STC and CFC in goat milk were 682, 38.9, 4.03 and 0.62 × 10 3 cells per ml, respectively. Mean ECs overall for, Alpine and Nubian breeds were 4.75, 5.80, and 3.76, respectively. Average EC of Alpine milk was higher than of Nubian, whereas mean SCC of Alpine milk was lower than of Nubians. Mean EC of afternoon milk was higher than of morning milk. There were no significant correlations ( r) between levels of SCC and EC for separate or combined breed data, nor for separate or combined data of milking time. However, SCC showed significant correlation with CFC for the pooled data ( P < 0.05). The EC values had negative but highly significant ( P < 0.01) r values with % fat and protein in the milk. Results suggest that SCC and EC by current instrumentations may not be good indicators for bacterial cell counts in goat milk. Further studies are necessary to find optimal unit measures of EC instrument for caprine milk.