Calcium has an indespensable role in major body functions

Calcium is required for the transmission of nerve impulses.  This function gets impaired during acute calcium deficiency as in milk fever, resulting in weakened muscle activity, sternal recumbency and death in extreme cases.

It is required for muscle contraction and therefore, plays a key role in minimizing dystocia and post parturient ROP.

Calcium is a vital component  in the blood clotting mechanism.

It is the structural component of bones and hence, is of vital importance in growing animals.

  Economic importance  of milk fever :

Recent findings have shown that apart from the loss of milk and the cost of veterinary treatment, milk fever leads to a host of other problems, which seriously affect the productivity of the animal.

A highly significant relationship between post parturient hypocalcemia and dystocia, retained fetal membranes, ketosis and mastitis has been demonstrated.  Cows which recover from milk fever are more likely to develop ketosis and mastitis compared with those which do not have milk fever.  Milk fever in dairy is a risk factor for several reproductive diseases, such as dystocia, retained placenta, metritis and uterine prolapse.  Studies have also found that parturient paresis directly increased the odds of hypomagnesemia, abdomasal disease and ketosis.

The overall net effect is that occurrence of milk fever potentially reduces the mean productive life of a dairy cow by about 3 years.

ETIOLOGY of milk fever:

 

Dry pregnant cow	Milking cow
Calcium requirement of a dry pregnant cow is 42 g/ day (approx.) Efficiency of calcium absorption in a dry pregnant cow - 33%	Calcium requirement of milking cow is: 82 g/day (approx.) Efficiency of calcium absorption required in a milking cow to prevent milk fever - 52%

From the above illustration, it can be observed that the amount of calcium required during lactation (82/day) is nearly twice the amount required during the last week of pregnancy (42g/day).  The efficiency with which, calcium has to be absorbed from the intestines also increases from 33% to 52% and it is this sudden change that can cause hypocalcemia and milk fever.

 Factors influencing the absorption of calcium from the GIT:

PTH & Vit. D₃ :  Calcium absorption from the Gastro Intestinal Tract (GIT) is dependent upon Parathyroid hormone (PTH) and Vit. D₃. 

When the cow calves and starts to produce milk, calcium output increases  dramatically, and concentration of calcium in the blood falls.  The reduction stimulates the secretion of PTH, which in turn stimulates the conversion of inactive Vit. D₃ to active form (1-25-dihydroxy-Vit. D₃).  Mobilization of calcium from the bone is stimulated by both PTH & Vit. D_3, whereas absorption from the intestines is only under the control of Vit. D₃.

About 24 hours of intestinal stimulation by Vit. D₃, is required before calcium absorption increases significantly.  The bone takes about 48 hours to respond.  It is these delays coupled with the continuous drain of calcium into milk, that cause hypocalcemia and milk fever. ( About 75% of the cases of milk fever occur within 48 hours of calving)

 CLINICAL SIGNS of milk fever:

The cow becomes recumbent in the sternal position, muscle activity is reduced (probably due to decreased transmission of nerve impulses during hypocalcemia) and the animal does not pass dung or urine.   Rumination is absent and the breathing is shallow with a slow heart rate.  Unless treated, this progresses to the terminal stage, wherein muscle activity is weakened further, the head lies on the flank, bloat develops, eventually stopping respiratory activity, leading to death.

 TREATMENT  of Hypocalcemia:

The conventional treatment is to administer an I/V solution of calcium borogluconate (25%) 450 ml.  Since Calcium borogluconate contains approximately 8.3% calcium, the net value of infused calcium would be about 9g.

Given that the losses of calcium into milk are approximately 1.2g/litre or 24g for a cow yielding 20 litres a day.  It can be seen that the amounts adminstered substitute for normal sources  only for few hours.

In most developed countries, the use of oral calcium supplements to maintain serum calcium levels after I/V treatment is strongly recommended.  In line with the above mode of treatment, VETCARE has recently launched its oral calcium supplement - 'CALUP GEL'.  CALUP GEL contains ioinc calcium  in gel form.  Serum levels of calcium rise within 15 minutes through 360 minutes of administration.  This implies that CALUP GEL effectively maintains serum calcium levels when used along with I/V calcium preperations in hypocalcemic cases.

Under field conditions, where follow up treatment of milk fever cases is problematic because of the distances involved, CALUP GEL would be an effective tool in the hands of the veterinarian to maintain serum calcium levels after I/V infusion and to prevent milk fever.

 TO RECAP:

Calcium plays a significant role in most of the body functions.

Milk fever is caused as a result of dietary calcium deficiency which seriously affects the productivity of the animal.

CALUP GEL, an oral calcium supplement, is an effective tool for maintaining serum calcium levels after I/V infusion and for prevention of milk fever.