Rapid Analyses of Amino Acids

A paper presented at the Australian Poultry Science Symposium earlier this year demonstrated the importance of rapid methods of amino acid analyses. The research group sampled meal and bone deliveries from two meat and bone suppliers to a feed manufacturer over a four-week period. A total of 45 samples were obtained and analyzed for crude protein, lysine and total sulfur amino acids using near-infrared spectrometric methods. The following table shows mean values and coefficients of variation for the nutrients for the composite samples and two suppliers:

	Composite sample	Supplier A	Supplier B
Number of samples	45	24	21
Crude protein (%)	52.4	49.9	55.4
Coefficient of variation	7.1	6.3	2.8
Lysine (%)	2.97	2.80	3.17
Coefficient of variation	11.1	11.9	5.7
Total Sulfur amino acids (%)	1.18	1.13	1.24
Coefficient of variation	8.7	8.8	5.5

One can see clear differences in values between the two meat and bone meal suppliers. The meal from supplier B had higher levels of crude protein and two amino acids, plus having lower coefficients of variations, which meant that supplier B was providing a superior and more consistent product. The value of the meat and bone meal product from supplier B would be under-estimated if the nutritionist programmed their computer with nutrient values reflecting the composite meal. Reducing the feed ingredient variability allows the nutritionist to more accurately formulate diets that meet nutrient requirements and reduce needed safety margins.

Irish, G.G. and co-workers. 2003. Practical application of near infrared reflectance spectroscopy to predict amino acids in feed ingredients. Proc. Aust. Poultry Sci. Sym. 15:69.