Comparative amino acid digestibility in US blood products fed to weanling pigs

Blood products are commonly used in diets for weanling pigs, but the different processing techniques that are used in the production of different blood products may result in differences in amino acid (AA) digestibility among products. There are, however, no comparative data on the standardized ileal digestibility (SID) of AA among different blood products when fed to weanling pigs. Thus, the objective of this experiment was to compare values for the SID of crude protein (CP) and AA in spray-dried animal blood (SDAB), spray-dried blood cells (SDBC), spray-dried plasma protein (SDPP), avian blood meal (ABM), and in porcine blood meal (PBM), when fed to weanling pigs. Seven weanling barrows (initial body weight: 11.5 ± 1.1 kg) were equipped with a T-cannula in the distal ileum and allotted to a 7 × 7 Latin Square design with 7 diets and 7 periods in each square. One of the diets was based on casein, and 5 diets were based on a mixture of casein and each blood product. A nitrogen-free diet was used to measure basal endogenous losses of AA and CP. The SID of CP in SDAB, SDBC, and SDPP were greater (P<0.01) than the SID of CP in ABM and PBM (1.040, 0.945, 0.995, 0.704, and 0.689, respectively). The SID of lysine was also greater (P<0.01) in SDAB (0.998), SDBC (0.976), and SDPP (0.981) than in ABM (0.740) and in PBM (0.786), but the SID of lysine in ABM was not different (P>0.05) from the SID of lysine in PBM. The mean SID of indispensable AA was greater (P<0.01) in SDAB, SDBC, and SDPP than in ABM and in PBM. The mean SID of total AA was also greater (P<0.01) in SDAB, SDBC, and SDPP than in ABM and in PBM. In conclusion, the SID of AA in SDAB, SDBC, and SDPP is greater than the SID of AA in ABM and PBM, which indicates that inclusion of spray dried blood products in diets to weanling pigs may be preferred over inclusion of blood meal. No differences exist in the SID of AA between blood meal from avian or porcine species when fed to weanling pigs.