Faba bean is a grain legume rich in digestible protein and starch (1). It contains between 26.7-29.2% crude protein, 2,839 kcal/kg apparent metabolizable energy corrected to zero-nitrogen retention, and 7.5% crude fiber with variations depending on the cultivar (2). Faba bean is a pulse crop that can be cultivated locally in Alberta, and it is a great alternative that can partially replace the soybean meal in the diet, allowing poultry producers to reduce their feed costs (3).
Faba beans contain some antinutritional factors (tannin, vicine and convicine) which can reduce nutrient digestibility and cause undesirable physiological effects such as intestinal damage or growth depression (4). However, some antinutritional factors can have their negative effects removed by heating the beans (5), while heat-stable antinutritional factors can be reduced with soaking, dehulling, extrusion, pelleting, or fermentation (6, 7).
FABA BEANS FOR BROILER DIETS
Several studies have been performed to evaluate the effect of feeding faba beans to broilers. However, there is disagreement in the research findings from different authors. The difference in results can be due to differences in age and genotype of the birds (8) as well as the percentage of faba bean added, the cultivar, the treatment the seeds were submitted to prior to feeding, and the feed form.
It was observed that male broilers fed 30% of one of 5 tannin-free faba bean cultivars (from 7 to 21 d) had a higher weight gain and better feed conversion ratio than birds fed the control corn-soybean meal diet. Tannin-free faba bean also did not negatively affect performance or carcass weight (2).
In contrast, a different study (9) found no difference in weight gain and feed intake when comparing broilers fed a control soybean meal diet or with 20% replacement with low tannin faba beans from 1 to 21 days. However, the authors found that broilers fed faba beans had better excreta quality scores.
A different study also found no difference in broiler performance or carcass yield when broilers from 14 to 49 days were fed either a control soybean meal diet or a diet containing 31% dehulled-micronized faba beans (10).
Tomaszewska et al. (2018) fed broilers a control diet with soybean meal, a diet containing high-tannin faba bean in different concentrations (8/15% starter/grower diet or 16/22% starter/grower.) The diet did not influence broiler weight or feed conversion ratio during the experiment. It was also observed that the birds fed faba beans had increased villus length and thickness, therefore improving their gut absorptive capacity, maybe to counteract the negative effect of the antinutritional factors present in the diet (8).
Not only the inclusion level but also the feed form can influence the performance of broilers fed faba beans. When broilers (7-21 days of age) were fed different faba bean inclusions (0, 5, 10, 15, 20, or 25%) it was observed that in mash diets broiler growth rate decreased with the increase in faba bean inclusion, whereas in pelleted diets there was no difference in performance amongst the broilers fed different inclusions of faba bean (11). The author believes that the pelleting process generated enough heat to destroy the antinutritional factors that were detrimental to broiler performance.
A similar effect of feed form was found when 20% of faba bean was included in a pelleted broiler diet. No negative effect on performance was observed when compared to the control group (6). However, 20% inclusion on mash diets decreased feed intake and body weight (6).
Broiler body weight decreased linearly with the increase in the inclusion of faba bean in cold pellet diets (0, 8, 16, or 24%) with no negative effect on broiler health (12). However, the decrease in performance was only minor for diets with 16% or less faba bean inclusion.
When faba bean was fed to broilers (17-19 days) as the main protein source in pelleted or extruded diets, it was observed that the birds had a lower feed intake and, consequently lower body weight gain when compared to the control group. Longer retention of the faba bean diet on the upper gut and decreased palatability of the faba beans diets are believed to be responsible for the reduced feed intake observed in this experiment (13).
In general, most studies showed that faba bean did not negatively impact broiler body weight when they were from a cultivar low in antinutritional factors, fed in a treated form (pelleted) and in a lower inclusion (20% or less).
ECONOMIC ADVANTAGE OF FABA BEANS
Other than the economy of buying a local feed ingredient, immature or frost-damaged faba beans, which would be cheaper and undesirable for human consumption, can be fed to broilers without any negative effect on digestibility (14) or broiler performance (15). Surprisingly, low-quality faba beans had higher gross energy (7%) than high-quality seeds (15). It was also observed that faba beans (Fabelle, Snowdrop and Snowbird cultivars) that were planted later (therefore more prone to frost) had reduced antinutritional factors and better digestibility (14).
CONCLUSIONS
Several studies have shown that faba beans can be a suitable partial substitute for soybean meal in poultry diets. However, insecurity about faba bean availability hinders its adoption as a local poultry feedstuff. Better communication between pulse growers and the poultry industry might increase the use of sustainable and locally produced faba beans in poultry diets.
REFERENCES
1. Crépon, K., P. Marget, C. Peyronnet, et al.,. 2010. Nutritional value of faba bean (Vicia faba L.) seeds for feed and food. Field Crops Res. 115(3): 329-339. https://doi.org/10.1016/j.fcr.2009.09.016.
2. Usayran, N.N., H. Sha’ar, G.W. Barbour, et al. 2014. Nutritional value, performance, carcass quality, visceral organ size, and blood clinical chemistry of broiler chicks fed 30% tannin-free fava bean diets. Poult Sci. 93(8):2018-2027. https://doi.org/10.3382/ps.2014-03872
3. Tewatia, B.S., Jyotsana, A. S., Meetu, et al. 2022. Effect of dietary replacement of soybean meal with faba beans (Vicia faba L.) on the performance of broilers. Indian J. Anim. Nutr. 39(1): 81-87. https://doi.org/10.5958/2231-6744.2022.00011.1
4. Muzquiz, M., A. Varela, C. Burbano, et al. 2012. Bioactive compounds in legumes: pronutritive and antinutritive actions. Implications for nutrition and health. Phytochem Rev 11: 227–244. https://doi.org/10.1007/s11101-012-9233-9
5. Cardador-Martínez, A., K. Maya-Ocaña, A. Ortiz-Moreno, et al. 2012. Effect of Roasting and Boiling on the Content of Vicine, Convicine and L-3,4-dihydroxyphenylalanine in Vicia faba L. J. Food Qual. 35(6): 419-428. https://doi.org/10.1111/jfq.12006
6. Ivarsson, E., and H. Wall. 2017. Effects of toasting, inclusion levels and different enzyme supplementations of faba beans on growth performance of broiler chickens. J. Appl. Poult. Res. 26(4):467-475. https://doi.org/10.3382/japr/pfx016
7. Omar, A. E,. H.S. Al-Khalaifah, T.A. Ismail, et al. 2021. Performance, Serum Biochemical and Immunological Parameters, and Digestive Enzyme and Intestinal Barrier-Related Gene Expression of Broiler Chickens Fed Fermented Fava Bean By-Products as a Substitute for Conventional Feed. Front Vet Sci. 8:1-15. https://doi.org/10.3389/fvets.2021.696841
8. Tomaszewska, E., S. Muszyński, P. Dobrowolski, et al. 2018. The influence of dietary replacement of soybean meal with high-tannin faba beans on gut-bone axis and metabolic response in broiler chickens. Ann. Anim. Sci. 18(3): 801-824. https://doi.org/10.2478/aoas-2018-0019
9. Nalle, C.L., V. Ravindran, and G. Ravindran. 2010. Nutritional value of faba beans (Vicia faba L.) for broilers: Apparent metabolisable energy, ileal amino acid digestibility and production performance. Anim. Feed Sci. Technol. 156(3–4):104-111. https://doi.org/10.1016/j.anifeedsci.2010.01.010.
10. Laudadio, V., E. Ceci, and V. Tufarelli. 2011. Productive traits and meat fatty acid profile of broiler chickens fed diets containing micronized fava beans (Vicia faba L. var. minor) as the main protein source. J. Appl. Poult. Res. 20(1):12-20. https://doi.org/10.3382/japr.2010-00173.
11. Gous, R.M. 2011. Evaluation of faba bean (Vicia faba cv. Fiord) as a protein source for broilers. S. Afr. J. Anim. Sci. 41(2): 71-78. https://doi.org/10.4314/sajas.v41i2.71009
12. Koivunen, E., P. Tuunainen, L. Rossow, and J. Valaja. 2014. Digestibility and utilization of faba bean (Vicia faba L.) diets in broilers. Acta Agric. Scand. – A: Anim. Sci. 64(4): 217-225. https://doi.org/10.1080/09064702.2015.1020857
13. Itani, K., J. Ø. Hansen, B. Kierończyk, et al. 2022. Air-classified faba bean protein fraction as a substitute to soybean meal in pelleted and extruded broiler diets. Br. Poult. Sci. 63(1): 62-72. https://doi.org/10.1080/00071668.2021.1960949
14. Smit, M.N., R. F. Ketelaar, L. He, and E. Beltranena. 2021a. Ileal digestibility of energy and amino acids in three faba bean cultivars (Vicia faba L.) planted and harvested early or late in broiler chickens. Poult. Sci. 100(9):1-10. https://doi.org/10.1016/j.psj.2021.101332.
15. Smit, M.N., L. He, and E. Beltranena. 2021b. Feeding different cultivars and quality levels of faba bean to broiler chickens. Transl. Anim. Sci. 5(3): 1-18. https://doi.org/10.1093/tas/txab094
