Crude Protein Fractionation and Fiber Analysis of Commercial Non-Forage Fiber Sources for Ruminants in Central Iran

A total of fourteen dairy farms across the central province oflsfahan were visited for sampling wheat bran (WB) and beet pulp (BP) as the main commercial non-forage fiber sources fed to ruminants. Fiber fractions were determined using approved analytical procedures. Crude protein (CP) was fractionated into NPN (A), quickly degradable true CP (B)), moderately degradable CP (Bz), slowly degradable CP (B3) , and unavailable CP (C), based on the Cornell Net Carbohydrate and Protein Model. Descriptive statistics and correlation coefficients between fibers and CP fractions were calculated for all samples, and data for WB were analyzed in a completely randomized design. All fiber and CP fractions of WB except for C differed significantly across farms. The NPN, B3, and NDF were greater but CP, unavailable CP and B2 were lower in the WB of this study as compared to that of CNCPS feed library. The greater CP and lower fibers of BP used across Isfahan as compared to that ofother reports were translated into more soluble fiber and thus more ruminally available energy in the samples of this study. The NPN, B[, and C in BP were significantly greater than the values found in the literature. Results indicated the necessity of a more dynamic evaluation ofthe nutrients in by-products ifthe diet formulation is to provide a more predictable animal response.