Influence of feeding different levels of soybean meal in growing Friesian calves rations on: 1- digestibility, some rumen parameters, blood constituents and growth performance [electronic resource].

Includes references.

Fifteen male Friesian calves with average body weights of 150:!: 14 kg and 8:!: 0.94 month of age were used in this study. Calves were randomly distributed into three similar groups (five for each). The experimental rations were formulated as follows: ration 1 (R1): 63 % concentrate feed mixture (CFM) + 37 % clover hay (CH) (control), ration 2 (R2): 52.5 % CFM +7.5% soybean meal (SBM)+40% CH and ration 3 (R3): 47 %CFM +11 %SBM+42% CH. The partial replacement of CFM by SBM increased the CP% of rations 2 and 3. The CP concentration of the tested rations was 13.6, 15.6 and 16.6% for R1, R2 and R3. respectively. Nutrients digestibility tended to be higher (p<0.05) when SBM was supplemented at 11% than 7.5%. The TON%, The ME (M cal/kg) and NE (Meal/kg) and g CPI / ME Meal were higher (p<0.05) with feeding on R2 or R3 than R1, whiie the TON: CP ratio was higher (p<0.05) for R1 than R2 or R3. likewise, the digested dry matter (OOM%) was higher (p<0.05) by feeding calves on R2 or R3 than R1. The relative feeding values (RFV), relative feeding quality (RFQ) and quality index (Ql) were higher (p<0.05) when the rations supplemented with SBM. The total concentration of ruminal VFA was higher (p<0.05) for calves in R2 or R3 than R1. Blood urea-N and glucose concentration were higher (p<0.05) for calves in R3 than those in R1 and R2. The average daily gain kg/day and feed efficiency were higher (p<0.05) when animals were fed R2 or R3 than R1. It could be concluded that the replacement CFM by SBM at a ievel 11% level of total OMI would improve nutrients digestibility, average daily gain and feed conversion of the growing calves.

Summary in Arabic.

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