Looming restrictions in Europe on the (over)use of antimicrobials in farmed animals together with the growing world market for organic dairy farm products stimulate the exploration of alternative strategies for the control of mastitis. Alternatives under consideration include antibacterial teat seals, intramammary infusion of antimicrobials such as ozone, immune modulators like β-1, 3-glucan, and medium-chain fatty acids (MCFA) possessing inhibitory activities towards the most common mastitis pathogens. This paper describes, among other things, the effect of oral supplementation of a commercially available mix of MCFA (Aromabiotic, Vitamex, Drongen, Belgium) given to heifers and multiparous cows starting at 6 to 8 weeks prior to calving on the blood and milk neutrophil viability shortly after calving in a randomized controlled clinical trial. Neutrophils play an important role in the first-line immune defence of the mammary gland. Both heifers and multiparous cows suffer from immune suppression around parturition, characterized by a higher proportion of apoptotic (that is, less viable) blood and milk neutrophils. At the outset of the study, no significant differences in blood or milk neutrophil viability were found between supplemented and control animals. In non-supplemented animals, blood neutrophil apoptosis increased significantly between the start of supplementation and the first days after calving whereas no substantial change in blood neutrophil apoptosis could be observed in the MCFA-supplemented animals. Blood neutrophil apoptosis shortly after calving was higher in multiparous cows than in heifers. However, an identical effect of oral MCFA-supplementation on blood neutrophil apoptosis was observed for both heifers and multiparous cows. Similar results were obtained for milk neutrophil apoptosis in multiparous cows. Overall, the proportion of apoptotic milk neutrophils in early lactation was lower in the MCFA-supplemented group compared to the non-supplemented group. And when compared to blood neutrophil apoptosis, milk neutrophil apoptosis shortly after calving was higher in multiparous cows than in heifers. Oral supplementation of MCFA to heifers and multiparous cows from 6 to 8 weeks before calving appeared to suppress the natural drop in the systemic as well as the local innate immunity shortly after calving, independent of the cows’ parity. Oral supplementation of MCFA could offer an opportunity to stimulate the cellular immunity and support the cows in meeting their every-day challenges, particularly during the critical period around calving.
Source: Piepers et al. – NMC Annual Meeting Proceedings (2012) pp. 42-49. Complete abstract: www.m2-magazine.org > 012-28.02.2012