Monitoring of mycotoxins in feed of the Krasnodar Territory and their combined effect on the microbiocenosis of the gastrointestinal tract of cattle

Abstract

Diets for cattle are affected by fungi - producers of mycotoxins: hay, straw, silage, grain, concentrates. Highly productive cattle breeds are more sensitive to mycotoxins. It has been studied that mycotoxins have antibiotic properties, disrupting the biocenosis and functionality of the proventriculus of cattle. This leads not only to a disruption in the nutritional process of animals, but also contributes to a decrease in the enzymatic activity of the rumen microflora and thus facilitates the penetration of other mycotoxins into the animal body. When conducting sanitary and mycological studies of coarse and succulent feed, compound feed and feed additives for cattle, it was found that feed was affected by micromycetes in descending order Mucor sp., Fusarium sp., Aspergillus sp., Candida sp., Penicillium sp. In the study of feeds, it was found that the most frequently recorded mycotoxins in descending order, T-2 toxin, aflatoxin, zearalenonone, ochratoxin A, fumonisin. Monitoring studies found that feed for cattle not containing mycotoxins was 33.4%, containing one mycotoxin 34.8%, two mycotoxins 28.8%, three mycotoxins 3.03%. When conducting scientific and economic experiments, the content of two mycotoxins in feed was diagnosed, the concentration of which for zearalenone was 1.0 mg / kg, for aflatoxin - 0.04 mg / kg. To study the effect of mycotoxins on the microflora of the gastrointestinal tract (proventriculus), an experiment was carried out on 40 bull calves of 7 months of age. The experimental group of animals (20 animals) was given feed contaminated with mycotoxins, the control group received a diet without mycotoxins. the contents of the rumen were collected on days 10, 20, and 30 of the experiment. The clinical picture in experimental animals with combined mycotoxicosis during the experimental period was characterized by a decrease in feed consumption by 10-20%, weight gain by an average of 18-25%, exhaustion, dullness of the coat, and alopecia. The difference between the experimental and control group of lactobacilli was 28.0%; 157.1% and 215.0% log10 CFU, respectively, for study days. Bifidobacteria 13.0%; 86.2% and 192.3% log10 CFU, respectively. The decrease in ciliates in the experimental group in comparison with the control on the 10th day of the experiment was 7.1 thousand units / g, on the 20 day 27.9 thousand units / g, on the 30th day 77.2 thousand units / g. Thus, the content of the main joints of the biocenosis in the rumen of cattle on days 10, 20 and 30 of the experiment was significantly reduced in the experimental group, the diet of which contained the association of mycotoxins. The monitoring carried out indicates that mycotoxins (in descending order) are most often recorded in feed for farm animals in the Krasnodar Territory: T-2 toxin, aflatoxin B1, zearalenone, ochratoxin A, fumonisin. A high contamination of feed and raw materials with molds was established - Mucor sp., Fusarium sp., Aspergillus sp., Candida sp., Penicillium sp. A decrease in the main representatives of the biocenosis actively participating in the digestion of cattle: lactobacilli, bifidobacteria, ciliates, under the influence of the combined effect of mycotoxins, has been established.