There is a mantra that the 3-week transition period each side of calving, critically important to the productivity and health of cows and their calves, is as easy to ignore as a background radio. I think it is worth re-stating and action taken where improvements can be made.
Calcium is not just critical for bones and teeth – it is integral to the operation of smooth muscles, so maintaining blood calcium levels is essential if calving is going to go well. Imagine the forces required to move 200 litres of wet rumen fluid full of long forage. How easily would rumen function be affected by poor muscular function at a time of the year when low dry matter forages limit rumen fermentation rates anyway? A quickly growing unborn calf and the production of calcium-rich colostrum will test the ability of cows to mobilise bone calcium as calving approaches. However, older cows are especially at risk because they tend to come into milk faster but mobilise bone calcium slower than younger cows.
We are all slaves to our hormones but calving cows are under extra pressure because the hormones secreted to relax ligaments in preparation for expelling a calf are not specific to the birth canal. Suspensory ligaments that normally take the weight of the cow on the wall of the hoof also relax and increase the risk of bones bruising the very sensitive cells that produce the sole tissue. The digital cushion, which works like a gel insert in sports shoes, is not fully developed in 2 year old cows and is thinner in cows with a lower Body Condition Score (I think the “Recent Advances in Lameness Control” seminar by Professor Jon Huxley makes for interesting viewing – available on YouTube). Ensuring cows calf down in the optimum condition with good appetites is not only going to impact on their production and fertility but also their vulnerability to sole ulcers, which may take 3 months to grow through to the surface of the sole.
Add to this a mix of evolutionary strategy in all mammals for reduced immune response around parturition, an egg that takes about 90 days to mature (and is sensitive to hormonal and chemical signals) and a suppressed appetite in cows so they keep close to their young rather than wander off for fresh pasture. You have a potent biological mix with some potentially negative consequences.
NRM Pre-Calver Pellets have been specifically formulated with anionic salts to encourage bone mobilisation before calving to meet the growing needs of the calf and colostrum production. They have added protein to lessen the need for cows to mobilise body protein reserves. An ME of 12.5MJ/kgDM is impressive given their high mineral loading and reflects a high content of readily fermentable grains, which can help reduce the risk of sub-clinical ketosis. A high trace mineral and vitamin content in addition to Bovatec® add to the suite of ingredients selected specifically to help cows transition to lactation. They are worth considering by anyone looking for increased peace of mind this calving season.
For further information, contact your local Nutrition Specialist.
Article supplied by Dr. Rob Derrick, Nutritionist, Farmlands.