Nutritional evaluation of two agroindustrial by-products for ducks and pigs

Forty-eight male White Pekin ducks and 24 crossbred barrows (Landrace or Yorkshire sows; PIC Line 355 boars) were used in three experiments to evaluate the nutritional value of two by-products generated from agricultural industries. In each experiment, test ingredients consisted of a dried meat solubles product (DMS) from swine processing facilities and a yeast fermentation product (YFP) from a commercial source. Soybean meal (SBM) with a CP content of 48% served as the control ingredient in the three experiments. Different batches of each by-product were evaluated in the three experiments utilizing an apparent ME (AME) assay for poultry (Exp. 1 and 2) and a digestibility assay for barrows (Exp. 3). The nitrogen-corrected AME (AMEn) for SBM, DMS, and YFP in Exp. 1 were 2.909, 2.801, and 3.292 kcal, respectively. The AMEn for SBM, DMS and YFP in Exp 2 were 2.809, 3.207, and 3.565 kcal, respectively. In Exp. 3, diets were formulated such that the test ingredients provided the sole source of amino acids in each experimental diet. The AME of SBM, DMS, and YFP in Exp. 3 were 3.844, 2.208, and 3.552 kcal, respectively. Based on the results of the ME assay for poultry, the DMS product compares well to SBM and seems to be suitable for feeding to ducks. The YFP does not seem to be suitable for feeding nonruminant species based on poor ability to support nitrogen retention in both species (-36% and -20% in Exp. 1 and 2, and 20% in Exp. 3).