Impact of humic acid as an organic additive on the milk parameters and occurrence of mastitis in dairy cows

Abstract

Given growing concerns about the use of antibiotics in the treatment of animals, identifying organic alternatives as feed additives to improve animal health and the development of immune responses has become of interest in dairy farming. Humic acids (HA) seem to be a suitable alternative with a favorable impact on the health and production parameters of animals. This study aimed to determine the effects of an HA supplemented diet on milk parameters as well as the effects on somatic cell count (SCC) and the occurrence of mastitis in dairy cows during the peripartum period. Twenty dairy cows in the last stage of pregnancy were selected from a herd of 140 cows. The selected cows were randomly divided into two groups: control (C) and experimental (E). The two groups were fed the same feed mixture and group E was additionally supplemented with HA at a total dose of 100 g per cow per day during the last 50 days of pregnancy. The milk parameters (dry matter, lactose, fat, crude protein, casein and milk urea) and SCC of every cow, and the presence of mastitis, were checked on days 10 and 30 during the first month of lactation. The results of the study show that dietary supplementation with HA significantly reduced the milk urea (MU) content and SCC on the 10th day after calving but did not affect the other milk compositions. In addition to the decreased MU and SCC, the number of positive quarters detected by the California Mastitis Test was reduced by 20.0% and the occurrence of mastitis caused by coagulase-negative staphylococci (CNS). Based on the obtained results we can conclude that the addition of HA stabilizes the nutrient digestion, as was confirmed by a reduced MU content in the supplemented group. Their indirect beneficial effects improved the development of immune responses, resulting in decreased SCC and the occurrence of mastitis caused by CNS.