Clinical and sub clinical ketosis in dairy cows does deserve attention here. In the latest N.Z. trial even the scientists were surprised by how common it was to find ketone bodies in the blood of cows at levels higher than 1.2 mmol/litre….especially in the month just before calving and the month immediately after.
We need to understand where a cow gets her energy from and how she keeps her blood glucose constant.
Fatty body tissue plays a hugely important part in this whole process. Triglyceride is broken down into glycerol and non-esterified fatty acids or NEFA’s.
Cows absorb very little glucose from their gut. They have to make it instead. And they do this in the liver using amino acids, which are the very smallest unit of protein, plus propionate which is a short chain fatty acid that the starch fermenters produce in the rumen.
Ketone bodies are the good guys normally. They don’t need to be attached to a protein like NEFA’s do, which makes them easier to be transported around the body. Plus they are a source of energy in these tissues. Glucose is spared, which is just as well as pasture contains very little starch.
So its common for very high producing cows to have a high level of ketone bodies in their blood…often 3 or more mmol B-OH butyrate/ litre…without showing any signs of being sick. They are using KB’s as quickly as they are being made.
Clinical ketosis is a crisis driven condition. There is often another complicating factor involved like fatty liver, mastitis or an afterbirth that hasn’t come away.
It does deserve attention for these three reasons.
- It’s a condition that is easier to prevent and much harder to treat …a lack of appetite just makes things even worse for the cow at a time when she needs to be eating more and more.
- Ketosis is just one of the diseases on the energy deficiency spectrum. It’s the tip of the iceberg that can warn you of a negative energy balance situation.
- Energy deficiency affects the immune system and makes cows more susceptible to viral and bacterial infections.
So strive to have them in a good body condition before they calve. And this starts even before you dry your cows off.