Take a closer look at rumen-bypass protein source

08 Jan 2019

Rumen-bypass protein is essential in nearly every modern dairy ration, but few producers fully appreciate the impact that different sources can have on feed costs, cow performance and nitrogen excretion.

So says KW nutritionist Charlotte Ward, adding that balancing this year’s high protein grass silages is a typical example.

Rumen-bypass protein

“What’s needed are feeds that are high in rumen-bypass protein – otherwise known as digestible undegraded protein – but low in rumen-degradable protein, which is already in plentiful supply.

“With traditional DUP sources, such as soyabean meal, it’s difficult to avoid oversupplying protein to the rumen, which can’t be used by the cow and requires energy to both process and then excrete as nitrogen in faeces or urine.”

Higher ratio

Ms Ward explains that feeds with a higher ratio of DUP:RDP are a better choice. “The heat-treated soyabean meal SoyPass, for example, supplies 4.5 times the DUP per unit of RDP than soyabean meal.

“The type of feed also has an impact, with oilseed rape-based supplements supplying a protein quality – in terms of amino acid profile – that’s more closely matched to cow requirements,” she adds.

Trial results

In a recent Nottingham University trial, average daily yield increased 1.7 litres per cow when NovaPro rumen-protected rapeseed expeller replaced soyabean meal in the ration. It’s also around 12% less expensive for the same DUP supply.