Determination of Solubility and Potential of Acid Production of some Feedstuffs and Investigation of their In Vitro Fermentation in Natural and Induced Acidosis Conditions

This study was conducted to determine solubility and acid production of some feedstuffs in various fermentation conditions. The solubility was determined at a temperature of 39°C for 24 h and the potential of acid production (PAP) was measured by adding calcium carbonate to filtered fermentation medium. Fermentation of feedstuffs was performed in special gas production syringes both natural and induced acidosis conditions. Total feedstuffs had 316.1 g kg-1 and 11.72 mg Ca g-1 for DM solubility and PAP, respectively. The best regression model to estimate PAP was made by non-fibrous carbohydrates (NFC) for all feedstuffs (R2 = 0.91) and by soluble OM in DM for both high NFC and high crude protein groups (R2 = 0.83). In natural fermentation condition there was high correlation (r = -0.91) between pH and gas production. The rice hull and wheat straw had the highest and the sugar cane molasses and citrus pulp had the lowest pH in 6h natural fermentation condition. The rice hull, wheat straw, alfalfa hay, corn silage and sugar beet pulp were more resistant than others in induced acidosis. The results showed that solubility and NFC content can be used in models that estimate PAP of feedstuffs. Also determination of fermentation characteristics of some common and by-products or lesserknown feedstuffs in terms of acid and gas production in a short time is possible by presented screening methods.