Standardized total tract digestibility of phosphorus in camelina (Camelina Sativa) meal fed to growing pigs without or with phytase supplementation
A study was conducted to determine the apparent (ATTD) and standardized (STTD) total tract digestibility of phosphorus (P) in camelina meal fed to growing pigs and the effect of phytase supplementation on STTD of P in camelina meal. Eighteen growing pigs (average initial BW of 18.1 ± 0.70 kg) were placed individually in metabolism crates which allowed for the total but separate collection of feces and urine. Pigs were allotted to one of three experimental diets, containing either (1) 20% camelina meal without phytase, (2) 20% camelina meal with 500 FTU/kg phytase or (3) a constarch-gelatin based P-free diet, in a completely randomised design to give 6 replicates per diet. The P-free diet formulated to contain 18.0% CP was used to determine endogenous P losses (EPL) to estimate STTD of P in camelina meal. Pigs were fed their respective diets in 2 equal portions at 0830 and 1630 h. Daily feed allowance was based on the body weight at the beginning of experiment and was calculated to supply 2.6 times the estimated maintenance energy requirements. The experiment lasted for 14 d and pigs were adapted to their respective diets for the initial 9 d followed by a 5-d period of total collection of feces and urine. The ATTD of P and EPL were 55.4% and 108 ± 48.9 mg/kg DMI, respectively, whereas the STTD of P was 57.4%. Phytase supplementation increased (P < 0.05) the ATTD and STTD of P in camelina meal to 68.3 and 70.0%, respectively. Phytase supplementation increased (P < 0.05) P retention (66.8 vs. 54.6%) and reduced (P < 0.05) P output in the feces (0.50 vs. 0.71 g/d). The standardized total tract digestible P content in camelina meal was estimated at 5.45 g/kg.
Keywords: Camelina meal, endogenous losses, phosphorus, pig