Effect of toasting grain silages from field peas (Pisum sativum) and field beans (Vicia faba) on in vitro gas production, methane production, and post-ruminal crude protein content

Abstract

Legume grains such as field peas and field beans can be produced on a local level, and may be reliable sources of dietary protein and energy apart from common soybean and rapeseed meals. In ruminants, protein, starch, and carbohydrates from peas and field beans are fermented in large part before reaching the small intestine. The objective of this study was to evaluate the effects of a combination of ensiling and hydro-thermic treatment (i.e., toasting at 160 °C for 30 min) of grains of peas and field beans on the concentrations of post-ruminal crude protein (PRCP) and rumen-undegraded protein (RUP). Moreover, 24-h gas production and methane production were measured. For this, an in vitro batch culture system with ruminal fluid from sheep was used. Rumen-undegraded protein was determined using the Streptomyces griseus protease test. Scanning electron micrographs were used to visualize morphological changes of starch granules and their joint matrices in peas and field beans after ensiling, toasting, or a combination of both. Native pea grains contained crude protein (CP) at 199 g/kg DM, PRCP at 155 g/kg DM at a ruminal passage rate of 0.08/h ( K p8), RUP at 33 g/kg DM at K p8, and starch at 530 g/kg DM. Native field beans contained CP at 296 g/kg DM, PRCP at 212 g/kg DM at K p8, RUP at 54 g of/kg DM at K p8, and starch at 450 g/kg DM. The PRCP did not considerably differ among native and treated peas or field beans. Especially in the peas, RUP at K p8 increased after ensiling by 10 g/kg DM (i.e., 30%; P < 0.05). Toasting increased RUP ( K p8) in ensiled peas by another 28% ( P < 0.05). Toasting had no effect on PRCP or RUP when the peas or field beans were not ensiled before. Gas and methane production were not affected by any treatment, and scanning electron micrographs did not reveal structural changes on the starches doubtless of any treatment. Protein seemed to be more affected by treatment with ensiled + toasted peas than with ensiled + toasted field beans, but starches and other carbohydrates from both legumes remained unaffected.

Techno-economic evaluation of biogas production from food waste via anaerobic digestion

“…Furthermore, Kulivand and Kafilzadeh reported that 80% of gas production was achieved within 21 h using the rumen fluid 25 . Li et al 26 reported an optimum methane production of 14.9 mL after around 72 h, and Bachmann et al 27 reported that the optimum gas production for beans samples was at around 16 h. Dagaew et al 28 performed 96 h of biogas production in the AD process and found out that the optimum gas production was achieved at around 24 h.…”

Identification of Ruminal Fermentation Curves of Some Legume Forages Using Particle Swarm Optimization

“…Forages should have less of Part b, but for feeds containing high-value biological proteins, Part b should be increased, so that most of the protein could pass through rumen digestion and be absorbed. Gas production during in vitro incubation indicates ruminal degradation and microbial activity [ 27 ], and a higher b fraction indicates higher rumen undegradable protein (RUP) content [ 28 ]. Yuan and Wan [ 29 ], and Ayaşan et al [ 30 ] reported negative values for Part a, which is consistent with the findings of the current investigation.…”

Use of Heating Methods and Xylose to Increase Rumen Undegradable Protein of Alternative Protein Sources: 1) Peanut Meal

“…However, an excess of heat exposure (time or intensity) might also protect the protein from postrumen compartment digestion [15,16]. Studies have reported the effects of autoclaving [17], toasting [18], microwave heating [19,20], and xylose treatment [21] on the improvement of the RUP content of protein sources. However, there are still contradictory results regarding these methods [5,22].…”