Potential protein degradation balance and total metabolizable protein supply to dairy cows from heat‐treated faba beans

Abstract

The effects of pressure toasting (100, 118 and 136 • C for 3, 7, 15 and 30 min) on potential protein nutritional value of faba beans were evaluated with the NRC 2001 dairy model, by determining undegraded (RUP) and degraded rumen protein (RDP), undegraded (RUST) and degraded rumen starch (RDST), truly absorbed undegraded protein (ARUP), microbial protein (MCP RDP ) synthesized in the rumen from rumen-available protein, truly absorbed rumen synthesized microbial protein (AMCP), truly absorbed rumen endogenous protein (AECP), total metabolizable protein (MP) in the small intestine, and the protein degradation balance (PDB). The treatments increased RUP, RUST, ARUP and MP (p < 0.001), and decreased RDP, RDST, MCP RDP and PDB (p < 0.001), the effects increasing with increasing temperature and time. The treatments increased (p < 0.001) ARUP without affecting AECP and AMCP, so that the net absorbable total MP in the small intestine was increased. The PDB was reduced (p < 0.001) but never became negative. These results indicated that potential microbial protein synthesis would not be impaired due to sufficient nitrogen in the rumen, but the high positive PDB values with most treatments, except 136 • C for 15 min (PDB 2.0 g kg −1 DM) indicated that there were large potential losses of nitrogen in the rumen, particularly for the control with a value of 88.9 g kg −1 dry matter. It is concluded that predicted potential protein degradation balance and total metabolizable protein supply from faba beans were improved by the treatments.

Faba bean (Vicia faba) inclusion in dairy cow diets: Effect on nutrient digestion, rumen fermentation, nitrogen utilization, methane production, and milk performance

“…The chemical composition of FB used in our study (30% CP; 31% starch; 14% NDF) is similar to what has been reported in previous studies (Goelema et al, 1999;Yu, 2005;Larsen et al, 2009). Faba bean is widely grown in the region of Saguenay-Lac-Saint-Jean in Quebec, Canada.…”

“…Faba bean (Vicia faba; FB) is a valuable protein source (25 to 33% CP; Yu, 2005;Larsen et al, 2009;Crépon et al, 2010) and can be a practical alternative to SBM in the diet of high-producing dairy cows. Similar to other legume seeds, ruminal solubility and degradability of CP of FB is higher than CP of SBM (Rotger et al, 2006;Zagorakis et al, 2015).…”

“…Faba bean also contains a substantial amount of starch (32 to 44%; Yu, 2005;Larsen et al, 2009;Crépon et al, 2010), which makes FB an excellent source of energy, thereby reducing the need for use of costly cereal grains (e.g., corn) in dairy cow diets. The inclusion of FB in dairy cow diets can increase starch supply, which would shift ruminal fermentation toward more propionogenesis and less methanogenesis given the inverse relation-ship between propionate formation and CH 4 synthesis in the rumen.…”

Evaluation of the nutritional value of faba beans with high and low tannin content for use as feed for ruminants

“…The OEB value was positive in faba beans and negative in the barley, indicating potential nitrogen losses from the rumen using the beans as feed, and significant energy losses from the rumen using barley as feed. Our data was, to some extent, consistent with the results obtained by Yu et al 44 . who reported MP and OEB values of 89 and 101 g kg −1 DM for faba beans.…”

Carbohydrates molecular structure profiles in relation to nutritional characteristics of newly developed low and normal tannin faba bean varieties in dairy cows analysed by using standard methods and the vibrational molecular spectroscopy (Ft/IR‐ATR)

“…Fibre and oil contents are fairly low; however, there is a high level of linoleic and linolenic acids in the seeds(O'Kiely et al, 2017).According to results from energy values of different varieties of faba bean (Table2), Snowbird, Fatima and Vertigo had higher content of truly digestible non-fibre carbohydrates (tdNFC) compared to other varieties, but Fatima and Vertigo were similar to all of them. Results related to total digestible nutrients (TDN 1x ), digestible energy (DE 1x ), metabolizable energy (ME), net energy for lactation (NE Lp3x ), net energy for maintenance (NE m ) and net energy for gain (NE g ) were not significantly different (p > 0.10) among all different faba bean varieties Yu (2005a). reported a TDN 1x value of 81.1% of DM, ME-dairy (3.01 Mcal/kg) and NE L (1.92 Mcal/kg) in faba beans; NDS library in-dicates that the TDN 1x content of white-flowered faba beans is 78.5% of DM; these outcomes were not in agreement with the higher energy profiles obtained in the current research with faba beans that were grown in western Canada.…”