298 Comparison of Amino Acid Digestibility in Pulses Between Broiler Chickens and Pigs

Abstract

Abstract The difference in capacity and structure of the gastrointestinal tract of broiler chickens and pigs could influence the digestibility of amino acids (AA) in feed ingredients. Therefore, two experiments were carried out to compare the standardized ileal digestibility (SID) of AA in faba beans (FB) and three field peas (FP) cultivars between broiler chickens (Exp.1) and pigs (Exp.2). Four diets were prepared to contain FB, FP DS-Admiral (FPD), FP Hampton (FPH), or FP 4010 (FP4) as the sole source of nitrogen. A nitrogen-free diet (NFD) was also prepared to estimate the basal endogenous losses of AA. On day 21 post-hatch, 416 male broiler chickens with an initial body weight (BW) of 951 ± 111 g were allotted to 5 diets in a randomized complete block design with BW as a blocking factor in Exp.1. There were 8 replicate cages with 10 birds per cage for diets containing the test ingredients and 12 birds per cage for the NFD. All birds were fed the diets for 5 days. On day 26 post-hatch, birds were euthanized by CO2 asphyxiation and digesta contents from the distal two-thirds of the ileum were collected. Barrows (n = 20) with an initial BW of 30.2 ± 1.58 kg, surgically fitted with T-cannulas at the distal ileum, were used in Exp.2. The pigs were divided into 4 blocks based on BW and assigned to a 5 × 2 incomplete Latin Square design consisting of 5 dietary treatments and 2 experimental periods. The daily feeding allowance was calculated at 4% of the mean BW of the pigs in each block. The adaptation period was 5 days, followed by a 2-day collection of ileal digesta samples. Data from Exp.1 and 2 were pooled and analyzed as a 2 × 4 factorial treatment arrangement with the effect of species and test ingredients. There were no interactions (P > 0.05) between diet and species. For broiler chickens, the SID of Lys in FB, FPD, FPH, and FP4 were 91.3, 91.0, 92.5, and 85.1%, respectively, whereas for pigs the SID of Lys were 82.4, 85.7, 87.0, and 78.9%, respectively. The respective SID of Met in FB, FPD, FPH, and FP4 were 84.1, 87.3, 89.8, and 72.1% for broiler chickens. Furthermore, the SID of Met in FB, FPD, FPH, and FP4 for pigs were 71.5, 80.4, 81.8, and 68.1%, respectively. Field peas 4010 had significantly less (P < 0.05) SID of indispensable AA compared with the other ingredients, except for the SID of Trp. In conclusion, the SID of AA were significantly greater (P < 0.05) in broiler chickens compared with pigs, except for the greater (P < 0.05) SID of Pro in pigs and similar SID of Arg between both species.