Silage quality deteriorates with Clostridium spp. contamination, and if consumed, such silage jeopardises herd health and productivity. Minimising its occurrence reduces economic and animal welfare risks. The study investigated the influence of environmental and technological determinants on the Clostridium genus’ occurrence in silage. Analyses were conducted on 305 silage samples directly collected from farms located in all Polish provinces. Cultures and isolates were evaluated phenotypically and examined for occurrence of Clostridium spp., particularly C. perfringens and C. botulinum using PCR techniques. The results were statistically analysed using the ᵡ² test for continuous and Student’s t-test for non-continuous values. The most influential effect on Clostridium spp. occurrence is exerted by factors potentially associated with primary production, like the type of fertilisation and the contamination level of the ensiled feed material. Clostridium spp. was detected in 232 (76%) samples, and C. perfringens strains, predominantly toxinotype A, in 79 (26%). C. botulinum occurrence was not detected. Deterioration of silage by clostridia could be prevented by a properly conducted ensiling process with the addition of starter cultures, but the presence of spores mainly depends on primary production and the extent of contamination of the feed material.

The aim of the study was to present cases of botulism in animals found in Poland in 2019–2021. The analytical laboratory diagnosis and difficulties that occurred in the interpretation of the results are described. From 2019 to 2021, samples of serum, intestinal content, liver, spleen, kidney, faeces, wet feed, dry feed, ensilage, water and mixed samples of internal organs associated with 10 suspected animal botulism cases were sent to the National Veterinary Research Institute. Samples were analysed using a mouse bioassay and culture methods in combination with ntnh and bont gene detection. Among the ten putative botulism cases, only four (40%) were confirmed in the laboratory on the basis of the detection of botulinum toxin (BoNT) or the ntnh or bont genes. The remaining six (60%) were determined as probable despite observable characteristic clinical signs. The diagnosis of botulism in animals is a very difficult task, made so by the heterogeneity of Clostridium botulinum strains and possible loss of toxinogenicity during laboratory processing or the potential degradation of toxins. Laboratory diagnosis is a complex and problematic process which should utilise different prescribed methods for specific types of sample.

The role of silage feeding in the origin of an epizootic of encephalitic listeriosis in a sheep flock was investigated by use of a new direct Listeria-selective isolation and enumeration medium, in combination with serotyping and phage typing. The silage contained high numbers (about 10(6) cells/g) of a L monocytogenes strain indistinguishable with respect to serovar and phagovar from that isolated from the brains of sick sheep. These results provided unambiguous bacteriologic evidence of the epidemiologic link between silage consumption and listeriosis in ruminants.

Complex analysis of maize (Zea mays) yielding capacity and content of nutritive substances in silage and green mass depending on the phase of crop development and sowings damage due to frost was realized in the conditions of the Republic of Belarus. Yielding capacity of green mass in the analyzed sowings of hybrid maize Beliz on sod-podzolic light loamy soils was 75,1 n/ha at the stage of grain formation. Insufficient amount of positive temperatures at the beginning of vegetation stage was compensated by means of favourable weather conditions for growth and development of maize in July-September. In proportion to maize crops maturity there was stated the appropriate lowering of green mass. Taking place frosts lowered moisture content in crops. Yielding capacity of maize top biomass after cold spell was from 45,7 up to 44,8 c/ha. For the obtaining of the optimal amount of nutritive elements in the conditions of Vitebsk region of Belarus it was proposed to realize crop harvesting at the stage of milky-wax ripeness. The best composition of nutritive elements in silage was at the stage of milky-wax ripeness

Results of studies of the influence of two biological products produced on the basis of sapropel (putrid mud) of the Ganarata lake (Mostovski district, the Republic of Belarus) on quality of legume-grass silage were presented. It was established, that analyzed preparations could be used as the preserving agents for preparation of herbal forages. The preserving action of the preparations was caused by the intensification of lactic bacteria development in silaging mass for the account of humic acids, as well as by the fungicidal action of phenolic and carboxylic fractions of the preparation. Silage preparation in combinations with putrid mud preparations made it possible to lower the losses of a crude protein on 11,3-15,6%, sugar - on 33,3%, carotin - on 20% and to obtain forage with concentration of exchange energy 9,20-9,38 mJ per 1 kg of dry matter. Silage application in combination with biological products rendered positive impact on milking efficiency of cows, the average daily milk yields in the experimental cow groups were on 1,3-1,4 kg or 6,8-7,3% higher. Application of higher quality feeds made it possible to lower the expenses of forages on 0,04 fodder units. Research results proved that the analysed preparations from sapropel could be used as an efficient conservants for silage preparations. They made it possible to raise forage quality at the minimum expenses

Results of determination of yielding capacity, chemical composition of initial weight and silage quality of forages prepared from the binary mixtures of Japanese millet (Panicum curs-galli var. frumentaceum), millet (Panicum) and saccharine sorghum (Sorghum saccharatum) realized in the conditions of the Republic of Belarus were presented. Research results showed that the binary mixture of saccharine sorghum with blue lupine (Lupinus angustifolius) in ratio of 70% + 30%, respectively made it possible to obtain the highest efficiency (62,4 t/ha of green material, 15,1 t/ha of dry matter, 13,1 t/ha of fodder units). Mixed sowing of millet, Japanese millet and saccharine sorghum with blue lupine surpassed in productivity the single-crop sowing on 15,5-32,6%. It was established, that the silage produced from the mixture of sorghum and Japanese millet with lupine had higher energy and protein nutritive value: 0,86 and 0,98 fodder unit, respectively; 9,77 and 9,92 mJ of exchange energy per 1 kg of dry matter, respectively; 103, 3 and 108,4 grams of digestible protein per 1 fodder unit. High nutritive value and the best palatability of trial silos promoted the increasing of milk yield on 4,4-5,4% in comparison with the control tests. Haylage which was produced from drought resistant crops had high energy nutritive value: per 1 kg of dry matter there was noted 9,40-9,48 mJ of available energy, 0,89-0,94 fodder units with fodder unit provision with 102-114 grams of digestible protein

Research on preserving ability of the biological preserving agent Bioplant for grass and maize silage making was realized in the conditions of the Republic of Belarus. Application of Bioplant in course of grasess and maize encilaging promoted the faster accumulation of the significant amount of milk acid and decreasing of рН up to 4,1-4,2. Silage which was prepared with preserving agent Bioplant corresponded to the top grade of quality. Application of Bioplant for preparation of siloed forages promoted the reduction of losses at their storage. For example, in grass-legume and cereal silage there was a reduction of dry matter losses in comparison with control silage - on 4,7 and 4,2%, crude protein - on 5,6 and 5,0%, respectively. In maize silage the addition of the preserving agent there was stated the decreasing of nutrient losses in comparison with the control: dry matter - on 5,2%, crude protein - on 6,2%. Feeding of wedder hogs with the silage preserved by the preserving agent Bioplant provided higher digestibility of crude protein in comparison with the control group: on 3,2% in the conditions of grass-legume silage use, on 2,4% - in the conditions of feeding with cereals, and on 2,9% - in the conditions of feeding with maize silage

In the conditions of the Republic of Belarus there was realized comparative evaluation of chemical composition and nutritive value of silages produced on the basis of millet (Panicum) and maize (Zea mays), their productive action and economic efficiency of ensilage fodders in diets of young stock of cattle. Data of chemical analysis showed the benefits of millet silage. The content of crude protein, crude fat, carotene, calcium and phosphorous was higher in millet silage. The analogous situation was in the analysis of biochemical indexes and energy value of dry matter. As a result of application of millet silage in diets of young stock of cattle made it possible to obtain 3,7 kg of body weight gain, while the expenses of forage per 1 kilogram of of weight gain lowered on 0,34 centner of fodder units, or 3,6%. Prime cost of 1 centner of fodder units in a diet in experimental group was on 57,3% lower than in a control one. Thus, use of millet silage in diets of heifers made it possible to lower the cost of fodders per 1 kilogram of weight gain on 63,2%, and prime cost of 1 kilogram of weight gain – on 19,8%.