Milk quality and prevalence of mastitis pathogens in infected bovine mammary glands and their sensitivity to local plant extracts

Abstract

The presence of pathogenic bacteria and antibiotics residue in milk is of public health concern. Traditional and established tests of mastitis diagnosis including microbial culture-based and somatic cell counts (SCC) microbial methods are standard for good health management in dairy industry. The objectives were: to identify the major etiological agents of bovine mastitis in the dairy herd and evaluate the influence of SCC on cow’s udders, to determine the effects of crude extracts of V. infausta and E. globules leaves on isolated mastitis causing pathogen 152 samples of milk from 38 milking cows were analysed, two SCC groups (group 1: ≤250 000 and group 2: >250 000 cells/mL) and this categorisation indicated that 76.9 % samples of the milk samples analysed were appurtenant to group 1 and only 24.1 % belonged to group 2. Milk somatic cell score (SCS) ranged from -5.6 to 2.12 (± 2.122) and milk yield ranged from 15.6 to 32.6 kg/d (±4.65). Milk fat, protein and lactose ranged from 2.99 to 4.11%, 2.78 to 3.30 % and 4.17 to 4.95 %, respectively. Mean SCC for each quarter was 2.58, respectively. From all quarter sampled, 62.5% were normal and 9.23 % had mastitis. The majority (62 %) of samples were normal and 17.8 % of teat canals were infected. Prevalence and distribution of isolated pathogens from quarter of the milk samples collected were arranged in 12 different SCC ranges. The results showed that 63.15% of pathogens are found in group 1 where SCC ranged from ≤ 2 ≤ 250³ and 17.11% of pathogens in group 2 with SCC ranged from > 250 > 2900³. Among the152 samples, 80.26% were cultured negative and 19.74% cultured positive. The results showed that the common pathogens isolated were coagulase-negative Staphylococci (CNS) (17 isolates, 56.66%) followed by Streptococcus uberis (5 isolates, 16.68%), Enterococcus spp (3 isolates, 9.98%), Enterococcus faecalis (3 isolates, 3.35%), Micrococcus (3 isolates, 3.35%) and contaminated (3 isolates, 9.98%). Extract of V. infausta did not show activity against CNS organisms at concentration lower than 0.020 g/ml and against other organisms at lower concentration than 0.025 g/ml. From 0.025 g/ml and 0.025 g/ml, CNS and other organisms, Micrococcus, E. faecalis and S. uberis were, respectively, inhibited. Extract of E. globulus exhibited activity against CNS at a concentration of 0.015 g/ml. Micrococcus and E. faecalis were inhibited from 0.020 g/ml while S. uberis were inhibited at the concentration from 0.025 g/ml.