Crude protein in corn and soybean meal have been documented to vary, and such inherent variability can result in under- or over-feeding of crude protein when feeds are formulated, leading to reduced bird growth, added input costs, and increased environmental pollution.

In the current issue of Journal of Applied Poultry Research, Dr Gene Pesti and colleagues at the University of Georgia report a study aimed to compare two grain-handling techniques and two feed formulation methods (linear versus stochastic programming) to reduce crude protein variability in finished feeds and determine resulting costs or savings.

The two grain-handling techniques were placing all the random batches of each delivered ingredient in to:

• a single bin ('one-bin method') or
• segregating above- and below-average samples into two bins ('two-bin method').

A fast way of estimating the composition of the ingredients is now available (near-infrared reflectance spectroscopy). Microsoft Excel workbooks were constructed to solve broiler starter feed formulation problems.

Formulating feeds by linear and stochastic models based on the two-bin method reduced crude protein variability by at least 50 per cent compared with the one-bin method.

Formula cost was reduced by around 20 US cents per ton (averages of August 2012 United States ingredient prices) when the two-bin method was used with the linear model.

Formulating feed with a margin of safety increased formula cost by $3.40 per ton.

Stochastic feed formulation increased formula cost to meet the specified crude protein level in feed at any probability of success, and formula cost was reduced substantially with the two-bin method – by up to $6.47 per ton.

The magnitude of savings and reduced feed variability suggested that, regardless of the costs associated with building extra bins, the two-bin method can be economically efficient in the long run.

Pesti and his co-authors conclude it could be possible to split the batches of feed ingredients at a feed mill into above- or below-average bins before feed formulation to reduce crude protein variability and to maximise savings.

Reference

Alhotan R.A., G.M. Pesti and G.J. Colson. 2014. Reducing crude protein variability and maximizing savings when formulating corn-soybean meal-based feeds. J. Appl. Poult. Res. 23: 456-469. doi: 10.3382/japr.2013-00934

Further Reading

You can view the full report (fee payable) by clicking here.

November 2014