# Effect of Steam Pressure Toasting Duration on Snowbird Faba Bean Seeds and the Impact on the Intestinal and Metabolic Characteristics in Dairy Cows

## TL;DR

Steam pressure toasting improves the nutritional value of faba bean seeds for dairy cows by increasing metabolizable protein and feed milk value.

## Contribution

This study demonstrates that steam pressure toasting modifies faba bean seeds to enhance intestinal protein supply and metabolic outcomes in dairy cows.

## Key findings

- Steam pressure toasting increased truly absorbed protein and metabolizable protein in dairy cows.
- Intestinally digested crude protein rose significantly with longer toasting durations.
- Feed milk value improved with steam pressure toasting, indicating better nutritional quality.

## Abstract

The response of feedstuffs to thermal processing depends on the type of feed and the thermal processing methods being applied. Steam pressure toasting (SPT) has been used recently to modify the nutrient degradability and enhance the nutritional quality of pulses. This study aimed to determine the effects of SPT duration in faba bean seeds (FBS) on the intestinal and metabolic characteristics of dairy cows. Our results show that SPT increased the nutrient values of FBS in terms of total metabolizable protein (MP), truly absorbed nutrient supply (DVE), and feed milk value (FMV).

The response of feedstuffs to thermal processing depends on the type of feed and the thermal processing methods being applied. Steam pressure toasting (SPT) has been used to modify the nutrient degradability and enhance the nutritional quality of pulses, including faba bean seeds (FBS). Strategic feeding approaches are essential for balancing diets and maintaining adequate nutrition, especially in high-performing ruminants. This research aimed to determine the effects of SPT duration in FBS on the intestinal and metabolic characteristics of dairy cows. Faba Bean seeds (three harvesting years) were processed at 121 °C for 0, 30, 60, 90, and 120 min. Rumen degradation and intestinal digestion were determined using the in situ and modified in vitro three-step techniques. The true protein supplied to the small intestine was also determined using the NRC and DVE systems. Our results showed a reduced total digested DM (TDDM) with longer SPT duration (quadratic, p = 0.02). The intestinally digested crude protein (IADP) increased from 62 to 220 g/kg DM with 0 to 120 min of SPT, respectively (p < 0.01), whereas the total tract digestible starch (TDSt) gradually decreased from 321 to 182 g/kg DM based on SPT time (p < 0.01). On the other hand, the truly digested protein in the small intestine (DVE) and the total metabolizable protein (MP) increased from 138 to 282 g/kg DM and 129 to 282 g/kg DM, respectively, with 0 to 120 min of SPT (quadratic, p < 0.01). The Feed Milk Value (FMV), based on both the DVE/OEB and NRC dairy nutrition systems, also increased with SPT (Quadratic, p < 0.01). The processing of FBS with SPT at 121 °C effectively reduced the highly degradable protein fraction in the rumen, shifting to a higher rumen undegraded protein (RUP) which was able to reach the small intestine. In the current study, the total MP, DVE, and FMV in dairy cows showed an overall increase with SPT in FBS.