Effect of feeding 3 zero-tannin faba bean cultivars at 3 increasing inclusion levels on growth performance, carcass traits, and yield of saleable cuts of broiler chickens

F. C. Kopmels, M. N. Smit, M. Cho, L. He, E. Beltranena, Effect of feeding 3 zero-tannin faba bean cultivars at 3 increasing inclusion levels on growth performance, carcass traits, and yield of saleable cuts of broiler chickens, Poultry Science, Volume 99, Issue 10, 2020, Pages 4958-4968, ISSN 0032-5791, https://doi.org/10.1016/j.psj.2020.06.034

broiler, carcass, chicken, dietary inclusion, faba bean, growth performance, peer-reviewed, Publication

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Faba bean (Vicia faba L.) is a high-yield pulse (low-fat legume) crop that shows potential as the substitute for conventional feedstuffs in broiler feed. Faba bean grain is rich in both starch (33%) and crude protein and grows well in temperate climate zones. Locally grown faba bean represents an opportunity to producers to reduce feed cost by displacing higher priced ingredients such as imported SBM. Feeding faba bean to poultry also has its downsides: Faba bean contains antinutritional substances (ANS) that can reduce feed intake and consequently growth. To mitigate the negative effects of tannins on feed intake and nutrient digestibility, white-flowered, low-tannin (so-called zero-tannin) cultivars of faba bean have been developed. The objective of this study was to evaluate the effect of feeding 3 zero-tannin faba bean cultivars at different introduction rates or inclusion levels on growth performance, carcass traits, and yield of saleable cuts.

Approach

In total, 662 male Ross 708 broiler chickens were used in the experiment. Chicks were individually weighed and randomly distributed among 64 cages, with 10 to 11 chicks per cage. On day 25, up to 2 birds (less if mortality had occurred) with the lowest BW per cage were removed to reduce stocking density to 8 birds per cage. In total, 10 different dietary treatments were fed. Dietary treatments were fed over 3 growth phases (starter, day 0 to 12; grower, day 13 to 25; and finisher, day 26 to 41) for the entire 41-day growth cycle. Control diets were wheat grain–SBM based. Dietary treatments included 3 different zero-tannin faba bean cultivars (Snowbird, Snowdrop, and Tabasco), each fed at 3 different inclusion levels: low inclusion level of 5% in the starter phase, 10% in the grower phase, and 20% in the finisher phase; medium inclusion level of 10% in the starter phase, 20% in the grower phase, and 30% in the finisher phase; and high inclusion level of 15% in the starter phase, 30% in the grower phase, and 40% in the finisher phase. Overall growth performance variables (ADFI, ADG, and G:F) and carcass yield were analyzed.

Analysis of Results

There were no interactions between faba bean cultivar and dietary inclusion level on growth performance or carcass traits. The most important finding in this experiment was that neither faba bean cultivars nor inclusion levels had an effect on overall trial or individual growth phase ADFI, ADG, G:F, or BW. Faba bean cultivar or inclusion level had no effect on antemortem WT or chilled carcass WT, but the high faba bean inclusion level reduced (P < 0.05) dressing percentage compared with the low and medium levels (74.3 vs. 74.9%).

Application

In conclusion, there was no effect of either faba bean cultivar (Snowbird, Snowdrop, Tabasco) or increasing dietary inclusion level (5, 10, and 20%; 10, 20, and 30%; 15, 30, and 40% for the starter, grower, and finisher phases, respectively) on growth performance, carcass traits, or proportional yield of carcass components. Our results indicate that zero-tannin cultivars Snowbird, Snowdrop, and Tabasco introduced at the high inclusion level (15, 30, and 40% for the starter, grower, and finisher phase, respectively) can be fed to broilers without affecting growth performance. Broiler producers can therefore feed the most aggressive of the 3 inclusion levels tested (15, 30, 40% for the starter, grower, finisher phase) and any of the 3 zero-tannin faba bean cultivars evaluated to maximize faba bean inclusion in broiler diets.

Abstract

A trial was conducted to evaluate how rapidly one could introduce faba bean in broiler diets and to what maximum level one could feed 3 zero-tannin faba bean cultivars to broiler chickens based on growth performance, carcass traits, and yield of carcass cuts. A total of 662 male broiler chickens (Ross 708) were fed one of 10 dietary treatments over 3 growth phases (starter [Str], day 0–12; grower [Gwr], day 13–25; and finisher [Fnr], day 26–41). Treatment diets included 3 different zero-tannin faba bean cultivars (Snowbird, Snowdrop, and Tabasco), each fed at 3 different inclusions: low inclusion level of 5% in Str, 10% in Gwr, and 20% in Fnr; medium inclusion level of 10% in Str, 20% in Gwr, and 30% in Fnr; and high inclusion level of 15% in Str, 30% in Gwr, and 40% in Fnr. Wheat grain–soybean meal (SBM) diets were fed as control. Faba bean cultivars replaced SBM and wheat grain in phase diets. Neither cultivar nor inclusion level affected overall trial or growth phase BW, ADFI, ADG, G:F, slaughter weight (WT), chilled carcass WT, and proportion of saleable cuts. Carcass dressing was 0.6% units lower for high vs. medium or low faba bean inclusion level (P < 0.05). There was no effect on overall trial or growth phase ADFI and there were only slight reductions (P < 0.05) in BW, ADG, G:F, slaughter WT, chilled carcass WT, dressing percentage, and percentage of drumstick yield in broilers fed the treatment diets including faba bean compared with those fed the wheat–SBM control diet. The control diet’s advantage was largely attributed to dehulling and the greater extent of processing to produce SBM vs. feeding raw, merely rolled, faba bean. In conclusion, broiler producers can feed any of the 3 zero-tannin faba bean cultivars evaluated as the most aggressive of the 3 inclusion levels tested (15, 30, 40% for the starter, grower, finisher phase) to maximize faba bean inclusion in broiler diets.