Nutritional Value of Faba Bean Cultivars as Dietary Source of Energy and Protein for Weaned and Growing Pigs
Creators: Nyende, Protus
Publisher: name: University of Alberta Library
Year: 2022

<p>Novel faba bean cultivars vary in nutrient content, digestibility and antinutritional factors that must be characterized to prioritize which faba bean cultivars to grow for pigs feeding.  In chapter 2, five diets included (20%, phase 1; 30%, phase 2) 3 different, zero-tannin and high vicine/covicine faba bean cultivars (Snowbird, Snowdrop and Tabasco) and 2 medium tannin cultivars (Fabelle, low vicine/covicine; Malik, high vicine/covicine). Diets were fed to weaned pigs to investigate their effect on nutrient digestibility and growth performance. Fabelle contained the most condensed tannins (CT; 0.53%) but the least vicine (0.04%) and covicine (0.0 1%). Zero-tannin cultivars contained little CT (&lt; 0.2%) but had the greatest vicine (averaged 0.5%) and covicine content (0.4%). For phase 1, energy and nutrient digestibility and growth performance did not differ among cultivar diets. For phase 2, diet apparent total digestibility (ATTD) of energy and CP was greatest (P &lt; 0.05) for Snowdrop and Tabasco, and lowest in Malik and intermediate for Snowbird or Fabelle. Diet net energy (NE) values was greater (P &lt; 0.05) for Tabasco than Snowbird, Fabelle and Malik and intermediate for Snowdrop. For the entire trial (day 0 to 28), the average daily feed disappearance (ADFD) was 10% greater (P &lt; 0.05) in pigs fed Fabelle than Malik and intermediate for pigs fed Snowbird, Snowdrop or Tabasco. Consequently, pigs fed Fabelle diet had the greatest (P &lt; 0.05) average daily gain (ADG) and final body weight (BW). In Chapter 3, two zero-tannin (Snowbird and Snowdrop) and 2 mid-tannin (Fabelle and Florent, high vicine/covicine) cultivars were included in 4 diets at 95%. Diets were fed to 8 ileal-cannulated barrows (37.5 kg) for four 9-day periods in a double 4 × 4 Latin square. A nitrogen-free diet was also fed to correct for basal endogenous losses of protein and amino acids. Analysed tannins content was double in mid-tannin cultivars than zero-tannin cultivars (14 vs. 6.9 g/kg). Vicine/covicine was lowest in Fabelle (0.6 g/kg vicine; 0.4 g/kg covicine) but greatest in Snowbird, Snowdrop and Florent (5.5 to 7.0 g/kg vicine; 3.4 g/kg covicine). Apparent total tract digestibility of dry matter and gross energy was greatest (P &lt; 0.05) for pigs fed Snowbird, intermediate for Snowdrop and Fabelle, and lowest for Florent.  Apparent ileal digestibility (AID) of starch was greater (P &lt; 0.05) in zero- than mid-tannin cultivars. Ingredient NE value was greatest in pigs fed Snowbird and did not differ among Snowdrop and Fabelle or Florent. The standardised ileal digestibility coefficient (CSID) of crude protein was greater in Fabelle, Snowbird, Snowdrop than Florent, with similar differences for lysine and most essential amino acids.<br>
In conclusion, Fabelle had greater growth performance than Malik in weaned pigs and greater energy, protein, and AA digestibility than Florent in growing pigs, likely associated with its lowest vicine and covicine. Furthermore, combined mid-tannin and, vicine and covicine possibly contributed to both lower energy and nutrient digestibility in pigs fed Malik and Florent than zero-tannin cultivars and should also be considered in prioritizing modern faba bean cultivars to feed to pigs. Across cultivars, variation in dietary total and resistant starch, crude protein and fibre contributed to difference in energy, protein and amino acid digestibility and should be considered in diet formulation.</p>