Different chemical and biological treatments (in vitro) and nitrogen supplementation were applied to improve the use of cereal straws in the diet of ruminants. The findings of the study resulted in the development of a method to adjust pH for dry treatment based on titratable capacity. Considering the reagent consumption and degradability, treatment with sodium hydroxide at pH 12 followed by ensilage may be regarded as the most effective dry method to improve the ruminal degradability of straw. Microbial protein and efficiency synthesis enhanced when the treated straw was supplemented with either urea or casein, but there was no additional benefit of altering N sources, or their level of synchrony. Moreover, feeding ensiled alkali-treated straw (65% of the diet DM basis) enhanced intake, ruminal and total tract digestibility, fractional dilution rate, urine pH and fecal consistency compared to feeding untreated straw. In lactation trial, straw treated with alkali (pH 12) and ensiled after adding 5% molasses and 10% ground wheat grain was included as one third of forage portion into the diet of mid lactation dairy cows. Total tract digestibility was similar between control (no straw) and treated straw diets. Dry matter intake averaged 24 kg and was unaffected by the forage sources. Milk yield was greater in cows fed control diet, but no differences were detected between control and treated straw diet niether in milk efficiency nor, in fat or energy corrected milk. Treatment with 7% alkali (pH?12) followed by ensiling appeared to be a promising process for improving cereal straw quality.
