Effect of treating wheat straw with NaOH on liveweight gains of cattle supplemented with molasses-ureia blocks

A uniform area of wheat stubble was divided into three paddocks, 1.2 ha each: A - standing stubble; B - baled stubble: and C - sodium hydroxide sprayed and baled stubble. Sodium hydroxide solution (40 g of NaOH per kg of straw) was sprayed into the chute of a forage harvester during the harvesting operation at the rate of 400 kg of solution per t of'straw. Each paddock was stocked with eight Friesian heifers and grazing was restricted to a 1/6 portion for the first week and extended to sucessive 1/6 portions weekly over a 42-day period. Urea, molasses and minerals supplement blocks were available ad lib in the three paddocks. Animals were weighed weekly and liveweight changes calculated as the coefficients of liveweight regressed against time. Liveweight changes were -352, -312, and +23 g/head/day on treatments A, B and C, respectively (C >A and B; P<0.01). Proportions of digestible organic matter in the dry matter in vitro, (DOMD) were 38 and 53% for untreated and alkali treated straws, respectively.