title: True and standardized total tract phosphorus digestibility in canola meals from Brassica napus black and Brassica juncea yellow fed to growing pigs.
abstract: The aim was to determine the true total tract digestibility (TTTD) and standardized total tract digestibility (STTD) of P in canola meals from Brassica napus black (BNB) and Brassica juncea yellow (BJY) fed to growing pigs. Fifty-four barrows with an initial BW of 19.9 ± 0.22 kg (mean ± SEM) were allocated in 3 consecutive blocks to 1 of 9 dietary treatments in a randomized complete block design to give 6 replicate pigs per diet. Dietary treatments were cornstarch based with increasing concentrations of P, that is, 0.8, 1.6, 2.4, and 3.3 g/kg (as-fed basis) from either BNB or BJY as the sole source of P and a gelatin-based P-free diet. Limestone was added to maintain a Ca:total P ratio of 1.2:1 in all diets. All diets contained titanium dioxide (3 g/kg) as an indigestible marker. Daily feed allowance was calculated to supply 2.6 times the maintenance energy requirement based on the BW at the beginning of each period and offered in 2 equal portions at 0800 and 1600 h as a dry mash. Pigs were individually housed in metabolism crates and fed experimental diets for 16 d, including 9 d for adaptation to feed and 5 d for total but separate collection of feces and urine. The apparent total tract digestibility values of P increased from 19.0 to 30.0% for BNB and from 17.3 to 28.3% for BJY as the dietary P content increased from 0.8 to 3.3 g/kg DM. The TTTD of P was determined using the regression analysis as dietary P content increased from 0.8 to 3.3 g/kg whereas the STTD of P was calculated for the diet with the highest P content (i.e., 3.3 g/kg, as-fed basis) using the P-free diet to estimate endogenous P losses (EPL). The total and basal EPL estimates obtained with regression analysis and the P-free diet were 665 ± 0.03 and 209 ± 96 mg/kg DMI, respectively. The TTTD of P was 33.3 and 32.0% in BNB and BJY, respectively. Respective STTD values were 31.0 and 28.3%. The results indicated that the TTTD and STTD of P were comparable in the 2 canola meals from BNB and BJY canola.
authors.affiliation: Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada R3T 2N2.
authors.forename: P A
authors.initials: PA
authors.lastname: Adhikari
authors.affiliation: Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada R3T 2N2 Department of Animal Science and Biotechnology, Chungnam National University, Daejeon, South Korea 305-764.
authors.forename: J M
authors.initials: JM
authors.lastname: Heo
authors.affiliation: Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada R3T 2N2 Martin_Nyachoti@umanitoba.ca.
authors.forename: C M
authors.initials: CM
authors.lastname: Nyachoti
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena / Q000502:physiology*; D000818:Animals; D001682:Biological Availability; D029688:Brassica napus; D002118:Calcium / Q000378:metabolism; D004032:Diet / Q000662:veterinary*; D004063:Digestion / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D041981:Gastrointestinal Tract / Q000378:metabolism*; D008297:Male; D009149:Mustard Plant; D010758:Phosphorus / Q000378:metabolism*; D011897:Random Allocation; D012044:Regression Analysis; D013552:Swine / Q000254:growth & development / Q000378:metabolism*
chemical_list: D010758:Phosphorus; D002118:Calcium
keywords: canola meal; endogenous loss; phosphorus; pig; standardized digestibility; true digestibility