Effect of balanced supplementary feeding in winter on qualitative and quantitative changes in the population of microbes colonizing the rumen of red deer

Abstract

Ruminants are a group of animals that process and assimilate their food in a unique manner. The functioning of the digestive tract of these animals is closely related to the abundance and composition of microbes in the forestomach, which is a complex ecosystem of bacteria, protozoa and fungi. Microorganisms present in the rumen, and in particular their effect on physiological processes in the body, influence the animal's physical condition and state of health. Microbiological examination of rumen microbiota ecology is hindered by a lack of selective growth media, as well as by difficulties in isolating bacteria in vitro and accurately identifying them. The aim of the study was to evaluate the effect of food consumed by red deer (Cervus elaphus) on the diversity of their rumen microbiota. Microbes were compared in two study periods. In autumn the animals' diet came exclusively from natural plant sources, while in winter, supplementary feeding was introduced, including specially prepared fodder. The study showed that in deer that did not receive the special fodder in winter, but only natural plant components, the abundance of bacterial flora decreased significantly compared with what it was in autumn, unlike in animals that did receive the fodder, whose composition and caloric value substantially increased the activity of rumen microbes. In winter, changes in proportions of different morphological forms of rumen bacteria were observed, as well as a decline in their total number, particularly in the animals that did not receive the pellets. A similar decline was also observed in the populations of yeasts and protozoa in winter. To sum up the results of the study, the use of the specially prepared high-calorie fodder in winter was shown to influence the rumen ecosystem of red deer. The most significant factor improving the condition of deer receiving supplementary fodder during this period is the stabilization of bacterial flora in the rumen, which directly contributes to the efficiency of digestion.