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.

OBJECTIVE To determine whether Mycobacterium bovis remains viable in ensiled forages. SAMPLE Alfalfa, mixed mostly grass, and corn silages. PROCEDURES For each of 10 sampling days, six 250-g replicate samples of each feedstuff were created and placed in a film pouch that could be vacuum sealed to simulate the ensiling process. Within each set of replicate samples, 4 were inoculated with 10 mL of mycobacterial liquid culture medium containing viable M bovis and 2 were inoculated with 10 mL of sterile mycobacterial liquid culture medium (controls) on day 0. Pouches were vacuum sealed and stored in the dark at room temperature. On the designated sampling day, 1 control pouch was submitted for forage analysis, and the other pouches were opened, and forage samples were obtained for M bovis culture and analysis with a PCR assay immediately and 24 hours later. RESULTS None of the control samples had positive M bovis culture or PCR assay results. Among M bovis-inoculated samples, the organism was not cultured from alfalfa and corn silage for > 2 days but was cultured from mixed mostly grass silage for 28 days after inoculation and ensiling initiation. Mycobacterium bovis DNA was detected by PCR assay in samples of all 3 feedstuffs throughout the 112-day observation period. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that properly ensiled forages would be an unlikely source for M bovis transmission to cattle. Further research is necessary to determine whether ensiling kills M bovis or forces it to become dormant and, if the latter, elucidate the conditions that cause it to revert to an infectious state.

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%.

Usage of preservatives Kormoplus 1 and 2 lets us produce the silage of a highest quality and raise dry substance integrity at 8,7%, protein - at 12-9,4%. The researches determined that cereal silage, prepared with supplement Kormoplus 1 and 2, lets us raise digestibility of dry substance at 5,5% and 3,7%, organic substance - at t 5,5 and 4,0%, fiber- at 16,5 and 15,0% and raise nitrogen sediment at 17,4 and 20,8%. These forages didn't have any negative influence at health and biochemical performance of cow blood

In the conditions of the Republic of Belarus there was studied the efficiency of application of forage chemical preservatives Kormoplyus-1, Kormoplyus-2, and Kormoplyus-3 for grass fodder conservation. The analyzed preservatives contained acetous acid, urotropine and sodium acetate (only in Kormoplus-2). In course of the study there were established experimental batches with the studied sreservative; there was determined a chemical composition of prepared forages; in physiological and scientifical and economic experiment there was analyzed the feeding efficiency of cereal ensilage. Research results showed that application of preservatives Kormoplyus-1 and Kormoplyus-2 2 for preparation of cereal ensilage made it possible to receive a high quality ensilage and to increase the dry matter safety on 4,2-8,7% and protein on 12-9,4% on comparison with storage without preservatives. Also, it made it possible to increase the digestibility of dry matter in cattle diets respectively on 5.5% and3.7%; organic substance - on 5.5% and 4.0%; fibre - on 16,5% and 15,0%, and also to increase nitrogen deposition on 17,4 and 20,8%. Feeding with forages preserved with Kormoplyus-1 and 2 did not render negative influence on a health state and biochemical indices of animal blood.