The Effects of Pistachio by-Product Silage Feeding on Microbial Protein Synthesis and Kidneys Function of Holstein Fattening Bulls

The study was conducted to examine the effects of compounds of pistachio by-product silage on the kidneys function and microbial protein synthesis in Holstein fattening male calves. For this purpose, levels of 0, 6, 12 and 18% of pistachio by-product silage (PBPS) were substituted with corn silage in twenty four Holstein male calves (155.1± 13.5kg). The calves were hosed in individual pens and 4 total mixed rations were feeding in a completely randomized design. The rations were fed adlibitum to the calves in a 6 month period. Microbial protein synthesis were predicted via spot sampling of urine for purine derivatives which measured by spectrophotometer for two consecutive days at 120 and at 180 days of experiment. Physical and chemical properties of urine were measured after the adaptation period to the rations and then every 45 day throughout the experiment. The results showed that increasing the levels of PBPS to 12 and 18%, microbial protein synthesis significantly (P<0.01) decreased in compared with control and 6% (PBPS) groups. No significant differences were observed between treatments for pH, specific gravity, white and red blood cells number and epithelial cells of urine. In spite of the urine dark color with increasing levels of PBPS, the calves were not affected by hemoglobinuria and hematory. As a whole, the results showed that phenolic compound of PBPS decreased microbial protein synthesis without detrimental effects on kidneys function in fattening male calves.