State of metabolic processes in cattle under the influence of biotic contaminants of feed

Abstract

Control of feed contamination by micromycetes and bacteria at all stages of their preparation, storage, and feeding of farm animals is an acute issue of feed safety and one of the principal measures that create an opportunity to prevent their negative impact on animal health. Therefore, the study aimed to investigate the state of metabolic processes in cattle of different physiological groups under the influence of biotic feed contaminants. The material for the research was grain fodder and coarse grinding grain of local production, roughage used on the farm. Veterinary and sanitary condition of grain products was established based on organoleptic, toxico-biological and microbiological studies. To determine the indicators of the state of metabolic processes, 3 groups of cows (n = 5–7) with different physiological conditions were formed: group I — non-pregnant cows, group II — pregnant animals with normal pregnancy, group III — cows after miscarriage. Biochemical parameters (level of total protein, albumin, globulins, vitamins A and E) in blood serum samples were determined spectrophotometrically by conventional methods. The study of the content of inorganic elements in the aggregate samples of bovine sera was performed using an X-ray spectrometer ‘Spectroscan MAX’. Laboratory studies have proven the presence of biotic contaminants in the feed base of the experimental farm. Exceedance of maximum permissible levels of feed contamination (max 16.50×104 CFU/g when MPL 5.0×104 CFU/g) by toxin-forming micromycetes (due to the genera Fusarium, Aspergillus, Penicillium, Mucor, and Rhizopus; a total of 24 isolates of microscopic fungi were isolated, which showed high toxicity in 11.3% and weak — in 20.1% of samples) and total bacterial contamination (max 18.7×105 CFU/g when MPL 5.0×105 CFU/g), in the structure of which coliform bacteria and Salmonella enterica were isolated. In cattle that consumed feed with an excess of biotic contaminants, disorders of the digestive tract (diarrhea) and reproductive capacity (abortions in the first half of pregnancy) were observed and metabolic disorders were found in cattle: increased Iron (on average 1.5 times) and Bromine (on average 1.6 times) levels, a decrease in the concentration of vitamin A (by 17.4–39.8%), and vitamin E (by 10.0–12.5%), most pronounced in cows after abortion and pregnant cows, respectively, Manganese (on average by 12.5%) and Selenium (by 30.7%)