P. Siroka

The effectiveness of biological treatment of wheat straw by white-rot fungi

Out of 13 species ofBasidiomycetes growing on wheat straw, 9 species enhanced thein vitro dry matter digestibility of the substrate. The detergent fiber content (acid and neutral) of the substrate was significantly reduced by most of the fungi tested. Hemicellulose showed the largest proportionate loss, whereas lignin the smallest one.

The effect of white-rot basidiomycetes on chemical composition and in vitro digestibility of wheat straw.

Five white-rot basidiomycetes were evaluated for their potential to improve ruminal degradation of wheat straw.Polyorus brumalis, Lyophyllum ulmarium III,Trametes gibbosa, Pleurotus ostreatus, and aPleurotus ostreatus mutant were incubated on wheat straw for 30 d at 28°C. Detergent fiber, crude protein andin vitro dry matter digestibility (IVDMD) were determined. The results showed increasing crude protein and ash contents in fungus-treated straw. IVDMD values were increased in straws treated withP. ostreatus, P. ostreatus mutant andT. gibbosa only. Relative to untreated wheat straw the detergent fiber content—neutral detergent fiber (NDF), and acid detergent fiber (ADF) was reduced in fungus-treated straw and out of three fractions—hemicellulose, cellulose and lignin, hemicellulose showed the largest proportionate loss whereas lignin the smallest one in all 5 samples of fungus treated straw.

Influence of diet and yeast supplement on in vitro ruminal characteristics

Abstract The effect of Yea-Sacc supplement on the level of rumen fermentation products in dependence on the diet has been investigated in the Rusitec fermentation apparatus. The solid and liquid components of the rumen contents of sheep fed a diet consisting of 80% meadow hay and 20% ground barley were used as an inoculum. Three experiments were carried out in which four fermentation vessels were each fed Diet 1 (80% meadow hay and 20% barley), Diet 2 (50% hay and 50% barley) and Diet 3 (65% hay, 20% barley and 15% treated beech sawdust). The yeast culture Yea-Sacc 1026 contained 10 8 live cells of Saccharomyces cerevisiae per gram and was added to two fermentation vessels every day at an amount of 0.5 g 1 −1 . Results showed that the Yea-Sacc supplement increased the digestibility of hemicellulose with Diets 1 and 2. The digestibilities of other parameters were not affected. With Diet 3 digestibility of dry matter, neutral detergent fibre, hemicellulose and cellulose were significantly lowered. Microbial proteosynthesis increased with Diets 1 and 3. No significant differences were found in the pH, ammonia N and gas production values. The volatile fatty acid production was variable. From the results it followed that the Yea-Sacc additive significantly influenced some aspects of rumen fermentation in vitro, which appeared to be dependent on the nature of the diet used.

Methanogenesis in rumen ciliate cultures of Entodinium caudatum and Epidinium ecaudatum after long-term cultivation in a chemically defined medium.

The methanogenic activity in the presence ofEntodinium caudatum andEpidinium ecaudatum was well preserved after long-term cultivation. Microscopic observation revealed that methane production in the presence ofE. caudatum was probably caused by their intracellular methanogenic activity, while methane production in the presence ofE. ecaudatum f.caudatum etecaudatum could be atributed to both the methanogenic bacterial fraction of their external surface and their intracellular activity. Methane production per protozoan cell ofE. caudatum andE. ecaudatum was 2.1 nmol per cell per d and 6.0 nmol. per cell per d, respectively.E. caudatum was responsible for almost the entire methane production in the culture. The activity of free methanogens constituted approximately 50% of the total methane production in thee. ecaudatum culture. Decrease of digestibility of substrates and differences in the fermentation end products accompanied the inhibition of methanogenesis in both cultures by penicillin G. streptomycin, chloramphenicol, 2-bromoethanesulfonate, and pyromellitic diimideE. caudatum appeared to be more sensitive thanE. ecaudatum to the compounds tested. Hydrogen recoveries based on both volatile fatty acids and methane production suggested that the methanogenic population appeared not to be fully able to consume hydrogen produced in the protozoan cultures. The culture conditions tested were found to be suitable for experiments on the relationship between rumen ciliate and rumen bacteria.

In vitro study of the rumen and hindgut fermentation of fibrous materials (meadow hay, beech sawdust, wheat straw) in sheep

Abstract The influence of both rumen and hindgut inocula of sheep on fermentation of fibrous materials in vitro has been investigated. Different fibrous materials (meadow hay, beech sawdust, wheat straw) and cellulose were used as substrates. The study was carried out to compare: (1) fermentation of substrates with rumen and hindgut inocula, (2) fermentation of meadow hay (reference substrate) and other substrates, (3) fermentation of the two types of cellulose (amorphous and crystalline), and (4) fermentation of treated fibrous materials (treated beech sawdust by defibration and impregnation and fungal treated wheat straw) and untreated fibrous materials. Hindgut fermentation of fibrous materials was associated with decreased dry matter and neutral detergent fibre degradabilities, and also methane and total gas production. The calculated hydrogen recoveries with hindgut inoculum showed a tendency to lower values as compared to the rumen inoculum. Significant differences were found between meadow hay and other fibrous materials, between both celluloses and between treated and untreated fibrous materials. The positive correlation between hydrogen recoveries and methane production of untreated wheat straw with a hindgut inoculum suggested the presence of reductive acetogenesis with the hindgut inoculum. It can be concluded that reductive acetogenesis with a hindgut inoculum instead of methanogenesis may increase the energetic yield from VFA per substrate, and to some extent also the energetic yield for the host animal.

Effect of Nisin on Two Cultures of Rumen Ciliates

The effect of nisin (in the form of Nisaplin) was determined using two species of rumen ciliate protozoain vitro, on their co-culture bacterial population, and volatile fatty acid concentration. Nisaplin did not affect thein vitro growth ofEntodinium caudatum at concentrations of 50–400 mg/L during short-term treatment (5 d). Long-term application (30 d) of Nisaplin (100 mg/L) significantly decreased growth of theEpidinium ecaudatum formacaudatum etecaudatum but not growth ofE. caudatum. Nisaplin moderately supported the growth ofE. caudatum after omission of wheat gluten (source of amino acids for protozoan growth). An inhibition of Gram-positive facultative anaerobic bacterial population in the protozoan cultures (lactobacilli, enterococci, staphylococci and amylolytic streptococci) was observed during long-term Nisaplin treatment. The concentration of volatile fatty acids significantly increased during the long-term Nispalin treatment of both cultures. The propionate concentration in the mixture of volatile fatty acids was nearly twice higher on the account of the decreased concentration (from 74 to 63 %) of acetate.

The comparison of in vitro fermentation kinetics estimated by three different methods

Three different methods for the estimation of in vitro fermentation kinetics are compared. The glass syringe, flow gasometer and pressure transducer methods were used for measurement of gas production. The rumen fluid from fistulated Merino sheep mixed with McDougalls buffer (1:1) was used as an inoculum and added at an amount of 35 ml into the fermentation vessels containing 0.25 g of meadow hay. The total gas produced was recorded after 12, 24, 36, 48, 60, 72 and 96 h of incubation. Hay dry matter degradability was the same with all three methods and achieved 56.5 to 58.2%. Total volatile fatty acids were significantly lower with the pressure transducer method than with the syringe and flow gasometer method. Lower values of mol% of butyrate and valerate obtained with the flow gasometer and pressure transducer methods in comparison with the syringe were also observed. Total gas production estimated by the flow gasometer method was lower than that stated by the two other methods. With regard to precision of the used methods syringe method was the best followed by the pressure transducer and flow gasometer method. It can be concluded that in spite of some limitations the pressure transducer method used in this experiment can be regarded as suitable for total gas estimation in in vitro rumen fermentation experiments.

Effect of monensin on fermentation of hay and wheat bran investigated by the Rumen Simulation Technique (Rusitec). 1. Basal parameters of fermentation.

An experiment was performed with Rumen Simulation Technique (Rusitec) in which the fermentation of mixed ration of hay (12.8 g/d) and wheat bran (3.2 g/d) was compared with the fermentation of the same diet in the presence of 2, 5 and 10 mg of monensin/d. The duration of the experiment was 12 days. During the first six days the fermentation conditions in Rusitec were stabilized. Monensin significantly depressed the digestibility of dry matter and fibre digestion--neutral detergent fibre (NDF), acid detergent fibre (ADF) and cellulose but only after using 2 mg monensin/d. Addition of monensin depressed the production of VFAs--acetate, butyrate and isovalerate and acetate:propionate ratio. Production of propionate was increased and production of methane and CO2 was decreased in the presence of monensin. It can be explained by changes in the production of VFAs and redistribution of metabolic hydrogen. The recovery of nitrogen was satisfactory (about 100%) and its distribution in the effluent was increased by monensin. The recovery of protein (measured as alpha--NH2 groups) and distribution of protein in the effluent and residues was increased with the increasing dose of monensin.

The effect of monensin on rumen fermentation in sheep fed on all-roughage and barley/roughage diets

Abstract The effect of 50 mg of Rumensin (monensin sodium) on rumen fermentation was studied in wethers fed on all-roughage (100% hay), high-roughage (75% hay, 25% barley) and concentrated (50% hay, 50% barley) rations. Monensin significantly increased the molar proportion of propionic and isovaleric acids and decreased the proportion of acetic acid and, with the concentrated diet, the proportion of butyric acid. No significant differences were observed in total VFA, pH, ammonia and blood urea. At the time of the most intensive fermentation (1, 3 and 5 h after feeding) the proportion of propionic acid in the monensin-treated group was similar in all diets (25.0, 25.3 and 26.2%), indicating that monensin increases propionate production more with high-roughage diets than with low-roughage diets. It is concluded that the effect of monensin is greater if given in high-roughage rations and that the performance of the roughage diets could be significantly increased by monensin supplementation.

In vitro fermentation of cellulosis amorphous and meadow hay in experimentally Ascaris suum-infected lambs

The objective of this experiment was to determine the effect of rumen inocula from experimentally Ascaris suum (AS)-infected lambs on cellulose amorphous (CA) and meadow hay (MH) used as substrates during 72h incubation in vitro. The rumen inocula were obtained post-mortem from eight lambs that had been experimentally infected with 1000 AS eggs per lamb daily for 3 weeks. Samples of rumen inocula were obtained from the lambs weekly throughout the experiment for 8 weeks. Two lambs were kept as uninfected control animals. The substrates were incubated together with buffered rumen fluid in sealed fermentation bottles. In vitro dry matter degradability (IVDMD), total gas, methane and total and individual fatty acid (VFA) for both incubated substrates were measured and compared by the pressure transducer technique. Comparison of the values for the controls, total gas, methane and VFA revealed significant differences (P<0.05, P<0.01, P<0.001, respectively) for both substrates. Pronounced differences (P<0.001) were also found between CA and MH especially for IVDMD, total gas and total VFA production. A decrease (P<0.001) of IVDMD, total gas, methane and total VFA was observed from week 6 to week 8. Restriction of fermentation was evident from week 7 to week 8. The results suggest that the functional damage arising from pathological lesions within the parasite-infected organs considerably affected the fermentation parameters of the incubated substrates.