The effect of wheat straw processed with cellulolytic bacteria isolated from gastrointestinal tract of horse on performance, digestibility, and fermentation and blood parameters in the fattening lambs

effect of these bacteriaon the performance of fattening lambs, digestibility, fermentation and blood parameters. Thirty Afshari male lambs with an average weight of 32 ± 3 kg and age of four months were used in a completely randomized design. The experimental treatments included diets containing wheat straw processed with four bacterial strains isolated from the gastrointestinal tract of horse (Paenibacillus polymyxa L11, Paenibacillus polymyxa L12Enterobacter cloacae L2 and Escherichia coli Z2) for 6 weeks; and the control treatment. The results showed that bacterial processing increased crude protein and decreased NDF, iNDF and ADF content, as well as increased organic matter digestibility (OMD) and metabolizable energy (ME) of wheat straw compared to the control. The highest amount of OMD and ME was assigned toL11. Apparent digestibility of DM, NDF and ADF, concentrations and ratios of ruminal volatile fatty acid (VFA), ruminal pH and ammonia nitrogen were affected by bacterial processing. The highest nutrient digestibility was assigned to the L11 and and the lowest amount was assigned to the control treatment. The lowest amount of ruminal ammonia nitrogen was observed in L11 treatment. Bacterial treatments increased total VFA, propionate concentration and decreased rumen acetate concentration. According to the results, processing of wheat straw with cellulolytic bacteria isolated from the horse's gastrointestinal tract (especially L11) improved nutritional value of wheat straw. Therefore, it seems that bacterial processing can be a suitable strategyfor better use of crop by-product with low nutritional value.