A new system of cow rationing has been devised by feed specialist, Trouw Nutrition. Peter Hollinshead reports.
Milk producers sticking rigidly with the old metabolisable energy (ME) system as a means of rationing their cows could soon find themselves out of pocket this winter.
That is because a radically more precise analytical model of the feed requirement of dairy cows has been produced by Trouw Nutrition, which looks at the Dynamic Energy (DyNE) available for milk production from all sources including the rumen, small intestine and large intestine.
“Dynamic Energy is the total amount of energy available for milk production and is the sum of the energy in the nutrients formed and absorbed in the digestive tract, including VFAs, glucose, amino and fatty acids,” said the company’s ruminant specialist Tom Goatman at the company’s launch at its Ashbourne headquarters.
“Based on the processes taking place in the animal, it is a more precise estimation of the energy available,” he explains.
The new research-based NutriOpt model has been developed using dacron bags in fistulated cows in the Netherlands to see what happens to feedstuffs once they reach the rumen and where else in the cow’s body they can be broken down to provide energy and protein.
This has led to what the company believes is the biggest breakthrough in the 15 years since the Feed into Milk model was released and is the product of a multi-million research funding by the group.
All the forage analysis which the company expects to perform this autumn will still go out with the familiar ME figures but this time additionally with new data like dynamic energy, digestible intestinal protein, and the fermentable energy and protein balance.
Which leads to this year’s discrepancy and possible confusion.
This year’s first cuts comprising 3,400 samples showed ME levels were slightly down on last year which could send out the message that producers need to supplement with more energy-rich concentrates. But paradoxically the new DyNE analysis shows these forages will actually perform better than expected.
“On the DyNE basis a cow eating 10kgDM of average quality first cut will have 3MJ DyNE more than last year. While on an ME basis 10kgDM would support 0.3litres less milk, on a DyNE basis it will support one extra litre of milk and the economic consequences in term of potentially reducing feed costs are significant,” he says.
However, the analysis also shows the fermentable carbohydrate levels are lower and cows may benefit from the addition of rolled or ground wheat with less slowly fermented ingredients like maize meal, or producers could increase the wholecrop inclusion as that will complement these silages.