New ‘3D’ feed analysis becomes a reality

A new approach to analysing the nutritional components of maize could produce a 10% improvement in its utilisation in rations and form a new base for re-evaluating all livestock feed materials in the future.

The work at the Arvalis Research Centre near Nantes in France is already attracting interest from seed breeding organisations, feed companies and other parties and could potentially lead to a wholesale rethink of many of the accepted values on which modern rationing is based.

Part of this is due to a growing understanding provided by the research of the relationship between the time a feed spends in the rumen and its ultimate nutritional contribution to the cow.

The parameters used in current feed analyses have been derived from a variety of techniques going back many years, explains Neil Groom of maize specialists Grainseed Ltd.

These have included using chemicals, enzymes and rumen juice in laboratory conditions and there is a wide discrepancy amongst many of these results.

The problem is that at best we use an average of these findings and at worse everybody uses different values. The other issue is that these figures are not based on what actually happens in the cow.

The In sacco method adopted by Arvalis uses a series of nylon bags containing accurately measured quantities of maize that are placed in the rumens of cows and these are retrieved at precise intervals over a 72 hour period. The sacks are then dried and weighed. From this the rate of digestibility can be ascertained along with fibre content. Starch and protein content is also determined.

Combining the values from the different timings produces a 3D nutritional map for the maize (or feed) sample in question charting various nutritional attributes over a period of time in the rumen.

Were already seeing a 10-15% variation in analysis from expected norms but the work is also helping us build a precise picture of how maize is digested in the bovine rumen and that in turn is leading to new ways of thinking about rations and maize utilisation, Neil Groom says.

Carrying out In Sacco analyses at different stages of maturity for the same variety is one of the ways of using the 3D approach but another is testing different varieties to build up a comparison of digestibility kinetics.

Two varieties can have the same overall digestibility, but when you look at them individually you can see one releases energy very quickly presenting an acidosis risk whilst another can be so slow at being digested, potential energy will pass through the rumen without being fully utilised.

It is in this area of comparison where the real potential for plant breeders lies, says Jean de Walsche of French maize breeding organisation Euralis Semences.

Were already starting to use the 3D approach with our new varieties, so we can say what the best way of using a particular variety in a ration is to achieve optimum energy utilisation – without the risk of feed wastage from too slow a breakdown or acidosis from too rapid a one. It actually makes you start thinking about what the optimum maize variety is and the whole rationing process in a completely new way.

These are very early days, but anything that can help increase the efficiency of animal feeding and ultimately food production has got to be good considering the challenges all producers face in feeding the world over the next 50 years.