Energy Value of Expeller-extracted Canola Meal Subjected to Different Processing Conditions for Broiler Chickens12 September 2014
Apparent metabolisable energy values varied markedly between samples of expeller-extracted canola meal in a study in Australia. Conditioning temperature, screw torque setting and fibre content were found to affect the energy value.
The effect of processing conditions and chemical composition on ileal digestible energy (IDE), AME, and AMEn of six expeller-extracted canola meal (ECM) samples subjected to conditioning temperature at 90, 95 or 100°C and high or low screw torque over the second presses in a 3×2 factorial arrangement have been examined by scientists at the University of New England in Australia.
In a paper in the current issue of Poultry Science, Bob Swick and his colleagues explain that the ECM samples were incorporated into a corn-soybean meal reference diet at 30 per cent by replacing energy-yielding ingredients.
A total of 210 day-old male broiler chicks (Ross 308) were fed common starter and grower diets until day 18, and then assigned to seven experimental diets replicated six times, with five chicks per cage.
After a five-day diet acclimation period from days 18 to 22, excreta was collected for 72 hours.
The difference method was used to determine AME, which was corrected to zero nitrogen balance to obtain AMEn.
Medium seed conditioning temperature resulted in the highest IDE, AME and AMEn compared with low or high temperature, and high screw torque resulted in higher energy utilisation than with low torque (P<0.001).
There was also an interaction (P<0.001) between conditioning temperature and screw torque. For ECM subjected to low or medium conditioning temperature at low screw torque, IDE, AME and AMEn values ranging from 2,137 to 2,705, 2,089 to 2,655, and 1,977 to 2,482 kcal per kg dry matter, respectively, were obtained.
The mean AMEn values were 2,260kcal per kg of dry matter, indicating a seven per cent reduction compared with AME values.
AMEn values were negatively correlated with neutral detergent fibre (NDF; r=−0.93; P=0.001) and NDIN (r=−0.87; P=0.001).
Stepwise regression to predict AMEn value resulted in the following equation:
AMEn (kcal/kg of DM) = 3,397.8 + (−100.1 × NDF%) + (279.5 × ash%) + (−33.8 × ADF%)
(R2=0.91; SE=61.9; P=0.001)
These results indicate that AMEn values vary markedly among ECM samples, and chemical constituents, especially the fibre components, may have a considerable effect on AMEn value.
Toghyani M., N. Rodgers, M.R. Barekatain, P.A. Iji and R.A. Swick. 2014. Apparent metabolizable energy value of expeller-extracted canola meal subjected to different processing conditions for growing broiler chickens. Poultry Science. 93: 2227-2236. doi: 10.3382/ps.2013-03790
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