Effect of the growing season duration of sorghum and Sudan grass hybrids on the chemical composition and digestibility of organic matter

In our experimental study we used the four most commonly grown (in the Czech Republic) sorghum and Sudan grass hybrids from USA (Nutri Honey, Latte, Honey Graze, Big Kahuna) and one hybrid from Germany (Bovital). The aim of the study was to compare these hybrids and to find out the influence of the growing season length on their nutrient composition and digestibility of organic matter. Samples were taken in the first cut, always in 14-day intervals. The crop was sown in early June, sampling started on July 19, 2010 and finished 8 weeks later on September 13, 2010.When assessing the influence of the growing season’s length the following values and development trends were discovered. Constant decreases over the testing period were recorded in nitrogen compounds – by 62 % (133.13 g), easily soluble sugars – 55. 5 % (40.06 g), organic matter digestibility 25.7 % (182.93 g) and NDF (neutro – detergent fibre) digestibility 31.5 % (73.2 g). Increasing trend, on the other hand, was recorded in fibre – by 30.4 % (99.2 g) and its individual components: lignin, NDF and ADF (acido – detergent fibre).In the second part of the experiment we were studying the differences in nutrient composition and organic matter digestibility between the individual hybrids. Honey Graze was recorded as having the highest average content of easily soluble sugars 57.53 ± 0.43 g, with lowest fibre content (272.13 ± 2.49 g), lowest ADF content (331.4 ± 2.88 g) and NDF content (440.4 ± 4.20 g) and lignin (77.47 ± 0.71 g). This hybrid also showed the best organic matter of (657.07 ± 5.28 g); however, no statistically conclusive differences (P < 0.05) in terms of organic matter digestibility were recorded between this hybrid and the other ones. The Bovital hybrid had the highest content of nitrogen compounds over the entire growing season (138.73 ± 0.94 g). Statistically highly conclusive difference (P < 0.01) in nitrogen compounds was found between this hybrid and all the other ones (except Big Kahuna). Upon all the indicators, the best rated sorghum and Sudan grass hybrid in terms of nutrient composition and organic matter digestibility was Honey Graze

The use of yeast culture in feeding of dairy cows

The aim of this study was to determine the effect of a yeast culture (Saccharomyces cerevisiae CNCM I – 1077) addition in the diet of dairy cows on their rumen fermentation. Animals received a diet consisting of good maize silage with a higher dry matter content (18 kg), 6 kg of lucerne haylage, 5 kg of pea – silage, 3 kg of ensiled high moisture crimped corn, 1 kg of meadow hay, rape-cake 1 kg, ­brewer’s grain silage 4 kg, and 8.0 kg feed mixture. The yeast culture was added to the mixture in the dose 2.8*1010 cfu / day and cow. The supplement of yeast culture showed a positive effect on ruminal VFA production by experimental group cows in comparison with control, higher production (P < 0.01) of acetic acid (58.50 ± 1.2583b vs. 51.833 ± 2.409a %), and lower production of propionic and butyric acid (24.667 ± 1.3744a vs. 28.833 ± 1.863b %). The average utilisation of ammonia was higher by cows in treated group (12.267 ± 0.754 mmol / L), but difference was not significant. The difference in number of protozoa of cows in the control and experimental groups was significant (P < 0.05) different (308.333 ± 24.390a vs. 342.333 ± 10.9341b ths /1 ml of rumen fluid)

Influence of Technological Process on Biodegradation of PVA/Waxy Starch Blends in an Aerobic and Anaerobic Environment

Zlepšení biologické rozložitelnosti blendů PVA se škrobem je již řadou prací dokázanou skutečností. Zhorší se sice poněkud mechanické vlastnosti výrobků (např. pevnost v tahu), ale vhodnou optimalizací složení příp. chemickou modifikací škrobu lze tento problém ve značné míře eliminovat. Předložená práce je pokusem o zjištění dalšího možného vlivu na biologickou rozložitelnost a to technologického postupu při výrobě folií z těchto směsí na extrudéru. Postup s tzv. před-extruzním krokem (dvoustupňový) a dry-blend (jednostupňový) poskytl blendy s velmi malými rozdíly z hlediska dosaženého biologického rozkladu (prakticky v rámci experimentální chyby); při aerobním (76 vs. 79%) i anaerobním rozkladu (48 vs 52%). Na druhé straně byla morfologickou analýzou prokázána lepší homogenita folií připravených dvoustupňovým procesem; také pevnost v tahu byla vyšší.Improving biodegradability of PVA/starch blends is a reality already documented by a number of works. Admittedly, mechanical properties of products (for example, tensile strength) are somewhat worse, but suitable composition optimizing or chemical modifying of starch may eliminate the problem to a large degree. This work is an attempt to find another potential effect influencing biodegradability, that of technological procedure for producing films from these blends on an extruder. The procedure with a so-called pre-extrusion step (two-stage) and dry-blend (single-stage) produced blends of slightest differences in achieved biodegradability (virtually within limits of experimental error) in aerobic (76 vs. 79%) as well as anaerobic higher.breakdown (48 vs. 52%). Conversely, morphological analysis exhibited superior homogeneity of films prepared by the two-stage processtheir tensile strength was als

Biodegradability and Mechanical Properties of Poly(vinyl alcohol)-Based Blend Plastics Prepared Through Extrusion Method

Plastic blend materials consisting of poly(vinyl alcohol), glycerol and xanthan or gellan were prepared through laboratory extrusion. Their base mechanical properties were compared with the properties of poly(vinyl alcohol) foil and their biodegradability in soil, compost and both activated and anaerobic sludge were assessed. In samples with lower polysaccharide content (10-21 %w/w) the tensile strength of 15-20 MPa was found; the elongation at break of all blends was relatively close to the parameter of poly(vinyl alcohol) foil. The biodegradability levels of the blends tested corresponded to the content of natural components, and the mineralization of the samples with the highest carbohydrate proportion (42 %) reached 50-78 %, depending on the type of the environment. Complete biodegradation of all samples occurred in activated sludge. © 2012 Springer Science+Business Media, LLC

Influence of various starch types on PCL/starch blends anaerobic biodegradation

Research concentrated on the biodegradable capability of PCL blends with various types of starch in an anaerobic aqueous environment of mesophilic sludge from a municipal wastewater treatment plant. For blend preparation, use was made of a native starch Meritena from maize, another from Waxy - a genetically modified type of maize, as well as Gel Instant, a gelatinized starch, and an amaranth starch. Additional PCL/starch blends were prepared from the same starch types, but these were initially plasticized with glycerol. The biodegradability tests were supplemented with thermo gravimetric analysis (TGA), and differential scanning calorimetry (DSC); morphology was identified using scanning electron microscopy (SEM), plus mechanical properties were also tested. While mixtures of PCL with starches plasticized with glycerol exhibited improved mechanical properties and a higher degree of biodegradation in the anaerobic environment, mixtures of PCL with pure forms of starch were ascertained as rather resistant to the anaerobic aqueous environment. TGA and DSC analysis confirmed the removal of starch and glycerol from the PCL matrix. SEM then proved these results through the absence of starch grains in the samples following anaerobic biodegradation. © 2013 Elsevier Ltd. All rights reserved