30% of cows suffer from subclinical ketosis after calving. The cause of ketosis or acetonaemy is a negative energy balance at the start of lactation as a result of the rapidly increasing milk production in combination with a more slowly increasing feed uptake.

In many cows, this leads to excessive mobilisation of free fatty acids (NEFAs) that are converted into energy or ketones in the liver. An excess of ketones in the blood is toxic to the cow, however, and leads to decreased appetite, additional weight loss and falling milk production. To minimise the negative energy balance, sufficient glucogenic energy must be supplied to fresh cows. The main building block of glucose in ruminants is propionic acid, a volatile fatty acid that is formed in the rumen through fermentation. After absorption into the bloodstream, propionic acid is further converted into glucose at the level of the liver.

DSM has developed Rovisol® Ketoblock: a patented supplement to cow feed during the transition period. Rovisol® Ketoblock increases the glucose supply for newly calved cows by stimulating propionic acid production in the rumen and optimising the conversion of propionic acid to glucose in the liver. Two recent trials show that starting up cows with Rovisol® Ketoblock yields 10% and 14% more propionic acid in the rumen, respectively. As a result of the improved glucose supply, cows suffer less weight loss after calving. Less loss of condition after calving is one of the first prerequisites for a metabolically healthy cow and promotes fertility. Low glucose levels in combination with high NEFA levels in the blood are, after all, disastrous for the quality of the ova.

Rovisol® Ketoblock causes both a reduction in NEFA concentrations in the blood and an increase in glucose production in the liver. In a comparative study, Rovisol® Ketoblock emerges as a worthy alternative to the preventive use of a Kexxtone bolus. In this way, Rovisol® Ketoblock fits perfectly into a mineral or concentrate feed for dry and starting cows. Moreover, in both trials the fat and protein-corrected milk production increased significantly by 3.7 L and 3.4 L respectively.

Dr I. Gantois - animal nutritionist ruminants

For more detailed information, please consult your contact at DSM Nutritional Products or Twilmij.