Energy concentration and phosphorus digestibility in canola, cottonseed, and sunflower products fed to growing pigs

Rodríguez, D. A., Sulabo, R. C., González-Vega, J. C. and Stein, H. H. 2013. Energy concentration and phosphorus digestibility in canola, cottonseed, and sunflower products fed to growing pigs. Can. J. Anim. Sci. 93: 493-503. Many protein sources are available to the swine feed industry, but accurate data for the energy concentration and the standardized total tract digestibility (STTD) of P in these ingredients are lacking. Therefore, two experiments were conducted to determine the concentration of digestible energy (DE), metabolizable energy (ME) and the STTD of P in oilseed products. In exp. 1, 48 barrows (44.8±3.9 kg) were fed a basal diet containing 97.15% corn or seven diets containing corn and canola seed (CS), canola meal (CM), cottonseed meal (CSM), sunflower seed (SFS), sunflower meal (SFM), de-hulled sunflower meal (SFM-DH), or soybean meal (SBM). Six pigs were allotted to each treatment. Sunflower seeds contained 5492 kcal kg⁻¹, at least 689 kcal kg⁻¹ more (P<0.05) ME than all other feed ingredients. Likewise, CS (4803 kcal kg⁻¹) had greater (P<0.05) ME than SBM (3676 kcal kg⁻¹), and both CS and SBM had greater (P<0.05) ME than CM, SFM, SFM-DH, and CSM (2998, 2725, 2631, and 2459 kcal kg⁻¹, respectively). In exp. 2, 84 barrows (13.7±1.5 kg) were allotted to 14 diets, which contained each of the oilseed products without or with phytase, in a randomized complete block design with six pigs per dietary treatment. The STTD of P in SBM was at least 4 percentage units greater (P<0.05) than the STTD of P in the other ingredients. Adding phytase to the diets reduced fecal output of P from all ingredients and increased (P<0.05) the STTD of P for all ingredients except SFM-DH. The ME concentration in SFS and CS is greater than that of SBM and the STTD of P among these ingredients is comparable, which indicates that SFS and CS may be fed to growing pigs at the expense of SBM.