Nutritional Value of Zero-Tannin Faba Beans

Zero-tannin faba beans are a potential replacement of soybean meal in swine diets. The chemical characteristics, energy and amino acid (AA) digestibility, the content of DE and NE, and tannin content of zero-tannin faba beans were determined and indicate, together with the subsequent growth performance variables and carcass quality of grower-finisher pigs, that zero-tannin faba beans can replace soybean meal and result in similar performance in grower-finisher pigs.

Introduction

Faba bean (Vicia faba minor) production is not new to Alberta. Research was completed in the early 1970’s; however, tannin and other antinutritional factors limited the use of faba beans in swine diets. Presently, zero-tannin faba bean varieties are available. The general purpose of this project was to remove barriers, which were preventing increased production and use of zerotannin faba beans in Alberta, especially in the Parkland and Peace regions. Analysis of the nutrient content of zero-tannin faba beans and a subsequent performance study confirming equal performance were thus needed. Objectives were (1) to determine chemical characteristics, energy and amino acid (AA) digestibility, the content of DE and NE, and tannin content of zero-tannin faba beans; and (2) to compare growth performance variables and carcass quality of grower-finisher pigs fed zero-tannin faba beans to soybean meal.

Experimental Procedures

One sample of zero-tannin faba beans was collected in Alberta.

Exp. 1. Digestibility Study

Energy and amino acid digestibility was tested using cannulated 60-kg barrows. Energy digestibility was tested in a diet containing 96% faba beans. Amino acid digestibility was tested in a diet containing 62% faba beans and 35% corn starch. Diets were fed at 3 x maintenance. Faeces were collected for 2-d followed by 2-d collection of ileal digesta. Standardized AA, DE and NE contents were determined.

Exp. 2. Performance Study

100 grower-finisher pigs in 20 pens had free access to either a soybean meal or faba bean-based diet regime from 30 –115 kg. Diets were formulated to equal Net Energy (NE) and Standardized Ileal Digestible Ammino Acids (SID) (Grower (30- 60 kg), 2.40/3.95; Finisher I (60-90 kg), gilts 2.38/3.15, barrows 2.38/2.76; Finisher II (90-115 kg), gilts 2.38/2.92, barrows 2.35/2.55; Mcal kg-1 NE/g SID lysine Mcal-1 NE, respectively), with up to 30% faba beans. Pigs were weighed, feed intake was measured, and carcass measurements were obtained.

Results and Discussion

The chemical characteristics (Table 1) and energy (Table 2) and AA (Table 3) profiles suggest that zero-tannin faba beans have a desirable nutrient content (slightly better than peas; NRC 1998). Overall, ADG (Figure 1) and ADFI (data not shown) did not differ between zerotannin faba beans or soybean meal (P > 0.10) suggesting that faba bean inclusion up to 30% might be possible without reducing ADG. The higher ADG for barrows during the Grower phase and higher lean depth for gilts fed soybean meal compared to zero-tannin faba beans (Figure 2) suggest that the available energy content needs further investigation.

Conclusion

In conclusion, the zero-tannin faba bean is a worthwhile protein ingredient to consider as a replacement for
soybean meal.

Acknowledgements

The AAFRD Industry Development Sector – New Initiatives Fund is funded the project. Alberta Pulse Grower – Zone 3 funded the zerotannin faba beans. Mr. Clayton Wierenga stimulated the start and Dr. Eduardo Beltranena the completion of the project. Strategic program funding to PSCI was provided by Sask Pork, Alberta Pork, Manitoba Pork Council, and Saskatchewan Agriculture and Food.

By R.T Zijlstra ¹, K. Lopetinsky ², B. Dening ³, G.S. Bégin ⁴, and J.F. Patience ⁵
¹ University of Alberta, Edmonton, AB;
² Crop Development Centre North, Edmonton, AB;
³ Alberta Agriculture Food and Rural Development, Barrhead, AB;
⁴ Alberta Swine Diet Formulators Corp. Edmonton, AB;
⁵ Prairie Swine Centre Inc. Saskatoon, SK.