In the second half of February and in early March we received about 100 mm of rain – 40 mm in one hour which ran off. We are not out of the woods yet but things are a lot better than they were a month ago.
We had just about run out of any standing dry (ie dead) feed which we had been supplementing with a urea molasses licker drum. Now instead of providing a protein source to help cows with fibrous feed, we need to give the cows some fibre to help with very high protein levels in the lush grass.
We are running three main mobs at the moment; spring calvers with calves about to be weaned, autumn calving cows with calves less than a week old and autumn calving cows yet to drop their calves. The 16 cows yet to calve are pictured in a paddock close to the house where we can see them easily.
Although there is good feed in the paddock it has a high water and protein content and we have provided them with a bale of cereal hay. The reasons we do this:
- the green feed is probably about 10% dry matter. To get 20 kg / day of dry matter the cow has to eat 200 kg of grass and excrete 180 litres of water. This can limit the cow’s intake and restrict production.
- the high level of protein in the feed can overload the liver’s capacity to metabolise the nitrogen and also reduces the absorption of magnesium which can lead to grass tetany, The hay also provides additional magnesium.
- It is better that cows have a firm rumen when calving as this assists the cow in pushing the calf out.
- The green feed in the paddock is limited and some hay supplementation will extend the time the cows can be kept under close observation in that paddock.
Our District Veterinarian told us this week that some Grass Tetany cases had occurred in the district which is a bit unusual for autumn. Further information on Grass Tetany here. [Touch Wood] We have never had any Grass Tetany. We feel that if cows prefer to eat some fairly coarse cereal hay rather than lush green grass they must need it. We can feed out a lot of hay for the price of a cow.