Without any doubt, the polyester-bag method is a very useful and common tool when evaluating ruminal utilization of feed. The first-order kinetic model as described by 0rskov & McDonald (1979), McDonald (1981) and Dhanoa (1988) is widespread and commonly used for description of disappearance curves. The model has two drawbacks clearly identified: (a) the assumption of fraction A being totally a...

KOPČEKOVÁ, J., ČEREŠŇÁKOVÁ, Z., FĽAK, P., MLYNEKOVÁ, Z.: Eff ect of mechanical processing of ce reals on rumen starch degradability. Acta univ. agric. et silvic. Mendel. Brun., 2010, LVIII, No. 2, pp. 139–146 Although starch in cereal grain is almost completely digested in the whole digestive tract, the rate and extent of ruminal degradation and fermentation vary widely with grain source and ce...

The aim of this study was to assess the effect of carvacrol supplement as a dietary additive to rumen fermentors, fed a barley seed:alfalfa hay (70:30) ration and to compare its effect with monensin supplementation. The material was incubated with goat ruminal fluid and four different treatments were included: no additive (C), 7.5 mg/l monensin (M), 250 mg/l carvacrol (C250) and 500 mg/l carvac...

Five steam-flaked sorghum grain (SFSG) samples with bulk densities of 476, 412, 347, 309 and 283 g/liter made by adjusting tension between mill rollers and three reconstituted sorghum grain (RSG) samples with reconstitution times of 10, 20 and 30 d and a control sample were analyzed for gas production kinetics (rumen liquor fermentation) and enzymatic glucose release (amyloglucosidase). Protein...

The current study evaluated the effects of electron beam (EB; 10, 20, 30 and 40 kGy), urea and NaOH treatments on chemical composition, phenolic compounds, in vitro gas production and i n situ ruminal degradability of pistachio by-product (PB). The EB decreased (p < 0.01) neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) contents of PB. Treating PB by NaO...

An experiment was conducted to determine the relationship between nitrogen intake and testicular urea content. Twenty ram lambs of fat-tailed Iranian native breed were used in this study. The mean (±SD) age and body weight of the lambs were 180±20 days and 36.7±6.3 kg, respectively. The lambs were divided in to five groups of equal size, and received a ration containing a single protein source;...

Twelve multiparous Holstein dairy cows in mid-lactation were selected for a replicated 4×4 Latin square design with a 2 ×2 factorial arrangement to investigate the effects of corn and soybean meal (SBM) types on rumen fermentation, N metabolism and lactation performance in dairy cows. Two types of corn (dry ground [DGC] and steam-flaked corn [SFC]) and two types of SBM (solvent-extracted and he...

Proanthocyanidins (PA) (condensed tannins) and hydrolyzable tannins (HT) are the two major classes of tannins. Proanthocyanidins are flavonoid polymers. Hydrolyzable tannins are polymers of gallic or ellagic acid esterified to a core molecule, commonly glucose or a polyphenol such as catechin. Proanthocyanidins are the most common type of tannin found in forage legumes. Problems in the analysis...