Tackling penalties for low lactose levels

Most of the dairy processors are changing the basis on which they pay for milk solids supplied. This is a concern to farmers who may be penalised for low lactose levels in their milk at certain times of the year.   The manufacture of lactose is essential to sustain high milk production and a typical cow requires about 72g of glucose to produce 1 kg of milk. If the level is significantly lower than a consistent five percent, the energy (glucose) of the diet is not adequate.   One of the reasons for this is when grass silage is substituted with maize silage, whole crop and/or alkalage. Another reason is that dietary molasses has been excluded or reduced due to price. The reduced availability of sugar beet is also a contributory factor.   Alternative forages are popular but they increase the sugar requirement of the animal. Maize is slow to release energy and requires quickly available sugar energy to balance. Whole crop and alkalage being high in fibre increase the sugar requirement so that rumen bacteria can break down the cellulose (fibre).   Some 60-80 percent of intestinal glucose is used by the animal itself with only about 15- 20 percent available for milk production. Where the supply is less than required or where the requirement has been increased (i.e. alternative forages) glucose is obtained by the animal from blood glucose so milk lactose levels falls.   Quality Liquid Feeds (QLF) will provide glucose plus lactose and high protein content similar to soya. In most cases total feed costs are reduced. Introducing this into the diet increases dry matter intake which improves dietary energy availability. This in turn optimises milk lactose levels so the problem is resolved.