Determination of the effects of chitosan addition to rumen fluids of different animal species on i̇n vitro digesibility of some roughage

The aim of this study was to determine the effect of chitosan addition to the rumen fluids of cow, buffalo, sheep and goat on the in vitro digestibility of commonly used roughages like alfalfa hay, alfalfa silage, corn silage, and meadow hay. Rumen fluids used in the study were obtained from cow (Holstein) (> 2 years old), buffalo (Murrah x Anadolu) (> 2 years old), sheep (> 5 months old) and goat (> 5 months old) from the slaughterhouse. Dry matter (DM), crude protein (CP), crude fiber (CF), ether extract (EE), crude ash, acid detergent fiber (ADF), acid detergent lignin (ADL), and neutral detergent fiber (NDF) were analyzed in the roughages. Relative feed values were calculated. İn vitro digestibility of feeds was determined by NDF analysis after 48 hours of incubation in Daisy incubator. The chitosan used in this study was prepared in 2.5% acetic acid solution. Before incubation, 16 ml of buffer solution was added to the groups with chitosan. At the end of the incubation, the washed and dried bags were weighed to calculate the in vitro true digestibility (IVTD) and in vitro dry matter digestibility (IVTDDM). At the end of the İn vitro digestibility assay, digested feed residues were analyzed for CP and, CF to ascertain the CF and CP digestibilities (CFD and CPD). Addition of chitosan to rumen fluids of different animal species decreased the IVTDDM, IVTD and, CPD of all the roughages (p<0.01) while no significant difference was noted in CFD. Similarly, the use of chitosan in four different feeds decreased the IVTDDM, IVTD and, CPD in buffalo, sheep, goat and cow animal species (p<0.01) whereas no significant difference in CFD. The use of rumen fluid from different animal species in alfalfa hay, alfalfa silage and meadow hay created a significant difference in IVTDDM, IVTD, CFD and CPD values (p<0.01). Maize silage created a significant difference in IVTDDM, IVTD and CFD values (p<0.01) while no significant difference in CPD value (p=0.055). In conclusion, it was observed that the addition of chitosan to the rumen fluid reduces IVTDDM, IVTD and CPD. This might be associated with the antimicrobial effect of chitosan. The findings of this study suggest that chitosan protects the dietary proteins from ruminal fermentation. In addition, results also reveal that there are differences in ruminal digestibility among the different ruminant species in all the roughages. The extent of IVTDDM in all animal species were: alfalfa silage> alfalfa hay> meadow hay> corn silage.