Based on data in a new study published in Journal of Applied Poultry Research, K.G.S. Wamsley and colleagues at West Virginia University have concluded that the original digestible lysine (DLys) and available phosphorus (AP) coefficients for corn DDGS are justified. However, the figures may underestimate availability by up to 0.08 and 0.02 percentage points, respectively.

Working together with POET Nutrition, the Morgantown-based researchers conducted two experiments to evaluate the utilisation of lysine (experiment 1) and phosphorus (experiment 2) in corn DDGS.

In these experiments, they used a 5 × 3 factorial analysis with variations in diet formulations for DLys and AP with increasing DDGS levels. Common performance metrics observed in both experiments 1 and 2 were average bodyweight, average live weight gain, feed intake (by pen) and FCR.

On day 43 of experiment 1, two birds per pen were chosen for analysis of carcass characteristics, and on day 21 of experiment 2, tibias were excised to obtain tibia ash measurements.

For both experiments 1 and 2, performance metrics improved with increasing levels of DLys and AP, respectively.

In experiment 1, there was a DLys × DDGS interaction where performance was best for diets containing high DLys and low levels of DDGS, and in experiment 2, DDGS inclusion had no effect on performance.

Regression equations were derived for each performance metric across DLys or AP levels and solved 2 ways:

1. using the observed metric resulting from each DDGS inclusion at the lowest DLys or AP level in the equation derived from no DDGS inclusion, and
2. selecting a common performance metric and comparing DLys or AP predictions across DDGS inclusions.

Reference

^{Wamsley K.G.S., R.E. Loar II, K. Karges and J.S. Moritz. 2013. The use of practical diets and regression analyses to determine the utilization of lysine and phosphorus in corn distillers dried grains and solubles using Cobb 500 male broilers. J. Appl. Poult. Res. 22(2):279-297. doi: 10.3382/japr.2012-00659}