Effect of Hypochlorite Oxidant or Extrusion on Nutrient Intake and Digestibility of Cotton Textile Byproduct by Holstein Heifers

Woldeghebriel, A., Bernard, J.K. and Mueller, T.C. 2000. Effect of hypochlorite oxidant or extrusion on nutrient intake and digestibility of cotton textile byporduct by Holstein heifers. J. Appl. Anim. Res., 17: 225–237. A 5x5 Latin square design trial was conducted to determine the effect of a hypochlorite oxidant and extrusion on nutrient intake and digestibility of textile mill byproduct (TMB) and compare TMB with pelleted cottonseed hulls (PCSH). Treatments included pelleted cottonseed hulls (PCSH), untreated (CONT), predigested with a hypochlorite oxidant (PD), extruded (EXT), and predigested. and extruded. (P&E) byproduct. Extrusion increased the bulk density of TBM by 32% and did not alter nutrient intake or digestibility compared with CONT. Dry matter (DM) and nutrient intake of heifers was not affected by treatment with hypochlorite oxidant. Apparent digestibility of neutral (NDF) and acid detergent fiber (ADF) was lowest for PCSH compared with TMB and was greatest for PD compared with CONT. Ruminal NH3 -N concentrations were highest for EXT but lowest for PCSH and PD. Molar proportions of propionate was greatest for PD and lowest for CONT and. EXT. In situ disappearance of DM and NDF indicated that TMB is digested very slowly and the rate of fermentation was not affected by oxidant or extrusion. These results indicated that fiber in TMB is more digestible than PCSH. Treatment of TMB did not improve in situ ruminal fiber digestibility, but hypochlorite oxidant appeared to potentially increase total tract fiber digestibility. Extrusion increased bulk density of TMB, but did not alter nutrient digestibility.