Milk Fever (Hypocalcaemia) and the Downer Cow
As calving season begins to get into full swing, stockmen all over Ireland and the UK will again be maintaining a close eye on their dry cows and as calving ensues, they will remain ever vigilant against the metabolic diseases that can befall their cows in the period immediately following calving. The most common of these diseases in Hypocalcaemia (aka Milk Fever) and Downer Cow syndrome.
Hypocalcaemia is a metabolic disease that generally affects high yielding dairy cows, although very milch suckling cows can also be affected. Clinical hypocalcaemia usually occurs within5-10% of the herd, although it has been seen to affect up to 50% of some herds. It is generally seen in cows that have had more than two calves and essentially is a problem with internal and dietary calcium supply and demand. At its most basic, there is a temporary deficiency of calcium within the cow's metabolism. The day before calving, the cow merely needs sufficient calcium to maintain her own requirements and that of the growing calf within. However, upon calving, the calcium required in the manufacture of colostrum and subsequently, milk, ramps up her metabolism calcium to a level above that which can be met by dietary requirements alone. As a result, the cow must mobilise calcium from her bones into her blood stream to meet these requirements. However, as cows get older, their bones become more refractory to the hormones charged with liberating calcium from her bones. It may also be noted, that about half of all hypocalcaemic cows have subnormal levels of blood phosphate, which may complicate the treatment of these cases. It is also to be remembered that magnesium plays a role in the ease at which calcium is mobilised from the bones.
As a result, a temporary deficiency ensues. All stockmen are familiar with the signs of clinical hypocalcaemia. They include dullness, weakness, inability to rise, loss of bowel motility and a delay in the ability to 'clean' or shed the afterbirth and if the cow is left untreated, death. All of these signs are merely reflecting the many functions that calcium serves within the cow's body.
There are a number of solutions that may potentially be employed to tackle a hypocalcemia problem. In the main, the solutions employed are relative to the severity of the problem. Where there is a serious problem, dietary manipulation using the Dietary Cation Anion Balance (DCAB) system is pursued. However, it is more common that the herd as a handful of 'repeat offenders' that always develop clinical hypocalcaemia after calving. In this situation it is advisable that one supplements using an oral treatment like Calcium Bovisal. Calcium Bovisal contains Calcium and energy in a highly palatable liquid. Where it is suspected that the cow has also low blood phosphate levels, Phosphor Bovisal which contains calcium and phosphorus in a palatable gel is advised. Both of these products can easily be used with infused Calcium borogluconate (Bottle of Calcium).