Anaerobic digestion of whole-crop winter wheat silage for renewable energy production

With biogas production expanding across Europe in response to renewable energy incentives, a wider variety of crops need to be considered as feedstock. Maize, the most commonly used crop at present, is not ideal in cooler, wetter regions, where higher energy yields per hectare might be achieved with other cereals. Winter wheat is a possible candidate because, under these conditions, it has a good biomass yield, can be ensiled, and can be used as a whole crop material. The results showed that, when harvested at the medium milk stage, the specific methane yield was 0.32 m3 CH4 kg–1 volatile solids added, equal to 73% of the measured calorific value. Using crop yield values for the north of England, a net energy yield of 146–155 GJ ha–1 year–1 could be achieved after taking into account both direct and indirect energy consumption in cultivation, processing through anaerobic digestion, and spreading digestate back to the land. The process showed some limitations, however: the relatively low density of the substrate made it difficult to mix the digester, and there was a buildup of soluble chemical oxygen demand, which represented a loss in methane potential and may also have led to biofoaming. The high nitrogen content of the wheat initially caused problems, but these could be overcome by acclimatization. A combination of these factors is likely to limit the loading that can be applied to the digester when using winter wheat as a substrat

Effect of heat processing on the nutritive value of mucuna bean (<i>mucun sloanei</i>) for rats

Mucuna bean (Mucuna sloanei, MB) is widely cultivated as a cover crop in a traditional bush fallow system of tropical regions. Despite its protein value and high yield in Nigeria, its use is limited to grazing animals. Its physical-chemical properties may be responsible for under-utilization. Like other legumes, Mucuna bean may contain antinutrients i.e., phenolic compounds which limit their utilization for man and animals. The utilization may be increased by either modifying or removing these compounds using simple processing methods. The following studies were conducted to test the efficacy of using physical-mechanical methods to improve the nutritive value of MB for rats and by implication for other species including human beings.</jats:p

Effect of heat processing on the nutritive value of mucuna bean (<i>mucun sloanei</i>) for rats

Mucuna bean (Mucuna sloanei, MB) is widely cultivated as a cover crop in a traditional bush fallow system of tropical regions. Despite its protein value and high yield in Nigeria, its use is limited to grazing animals. Its physical-chemical properties may be responsible for under-utilization. Like other legumes, Mucuna bean may contain antinutrients i.e., phenolic compounds which limit their utilization for man and animals. The utilization may be increased by either modifying or removing these compounds using simple processing methods. The following studies were conducted to test the efficacy of using physical-mechanical methods to improve the nutritive value of MB for rats and by implication for other species including human beings.</jats:p

4.2 Forage Protein and the Performance and Health of the Dairy Cow

In nutrition, as in any other branch of quantitative applied science, two essential criteria must be met before research findings can be transferred successfully into practice. (1) The fundamental concepts must be essentially sound and (2) the predictions emerging from that conceptually sound system must, in a practical situation, constitute a useful increase in accuracy. The new method proposed by the Agricultural Research Council (ARC, 1980) for expressing protein requirements and the value of feeds for ruminants is undoubtedly an enormous improvement in a conceptual sense on ARC (1965). Indeed, the division of protein inputs into rumen degradable nitrogen (RDN) and undegradable dietary nitrogen (UDN) cannot be faulted since it is the best possible simple description of what happens. Even the decision to retain the concept of crude protein (N x 6.25) and refer therefore to RDP and UDP is harmless. The new ARC protein system therefore fulfils the first criterion for successful practical application. The second criterion can only be fulfilled if ARC (1980) accurately describes both the requirements of animals and the nutritive value of feeds in terms of RDP and UDP. In the case of dairy cows, this is open to considerable doubt.</jats:p