An industry survey and an animal experiment were conducted to evaluate compositional variability and DE and ME content of animal protein by-products, and to generate equations to predict DE and ME content based on chemical analysis. For the 220 samples collected, the greatest concentration of CP was observed in blood meal (BM) and least in meat and bone meal (MBM), the greatest concentration of ether extract (EE) was in meat meal and least in BM, with ash content greatest in MBM and least in BM; with Ca and P levels being 36.1 and 16.3% of the ash content, respectively. For the balance experiment, a corn-soybean meal basal diet was used with test diets formulated by mixing 80% of the basal diet with 20% of the animal protein by-product, except for BM which was included at 10 and 20% of the test diets. Ten groups of 24 gilts (final BW = 92.5 Â± 7.4 kg) were used, with gilts randomly assigned to the test or the basal diet within each group, resulting in 16 replications per animal protein by-product or basal diet, except for BM determinations (20 replications). Gilts were placed in metabolism crates and offered 2.4 kg daily of their assigned diet for 13 d, with total collection of feces and urine during the last 4 d. Gross energy was determined in the diets, feces, and urine to calculate DE and ME content of each ingredient by the difference procedure, using DE and ME content of the basal diet as covariates among groups of pigs. The DE content of the animal protein by-products ranged from 5,367 to 2,567 kcal DE/kg of DM, and ME ranged from 4,783 to 2,340 kcal ME/kg DM. Using all animal protein by-products, the best fit equations were as follows: DE, kcal/kg DM = -2,468 + (1.26 Ã— GE, kcal/kg DM), with R2 of 0.84, SE = 390, and P < 0.01; ME, kcal/kg DM = -2,331 + (1.15 Ã— GE, kcal/kg DM), with R2 of 0.86, SE = 327, and P < 0.01). The apparent total tract digestibility (ATTD) of Ca and P were also determined using the difference procedure, with the average ATTD of Ca and P for the animal protein by-products, excluding BM and FM, being 27.1 and 39.1%, respectively. These data indicate that DE and ME varied substantially among the animal protein by-products and sources, and that a variety of nutritional components can be used to accurately predict DE and ME for finishing pigs. In addition, it appears that high dietary inclusion rates of animal protein by-products may result in low ATTD estimates of Ca and P, which may be due to excessive concentrations of total Ca and P affecting digestibility.
|Date made available||2017|
|Publisher||Data Repository for the University of Minnesota|