Ask Dairy - Lactating Cow

"Historically, lactating cows producing 35 litres of milk have been fed diets of 17% crude protein. However, recent research suggests that you can decrease this to as low as 15%. Have you ever tried applying this concept and, if so, what ration changes should be implemented?"

From experience, decreasing dietary protein from 17 to 15% does not necessarily lead to lower yield – it is all about choosing the right feedstuffs, calculating the ration adequately and focussing on nitrogen efficiency. However, you have to start with a good foundation -no feedstuff or ingredient can replace a good quality forage and good management. Once this is ensured, the nutritionist’s attention has to turn to optimal feeding of the rumen bacteria so that maximum microbial yield is achieved. One criterion to follow is the soluble crude protein to rumen degradable protein ratio as this really ensures maximal rumen microbial growth and activity. The danger of a ration below 0.52 is a lack of non-protein nitrogen in the rumen during the day but this can easily be overcome by the inclusion of Optigen. The solution is to feed the rumen first then complete the intestinal protein supply with a high quality protein source

Expert Answer by: Sylvie Andrieu