HIPOCALCEMIA OR FEVER OF THE MILK!

The hipocalcemia is a metabolic disturbance in which the mechanism of regulation of the levels of calcium in the blood is disturbed by the sudden and accelerated increase of the mobilization of that element in the beginning of the period of colostro production and milk. It is a common disease in cows milk pans of high production, appearing in general, starting from the second nursing and among 24 and 48 hours after the childbirth. The clinical picture of the problem is quite evident: there is a nervous excitamento, with tremors of head and tetania or muscular contraction, especially of the great muscular masses, besides protusão or exhibition of the language. The cows are sad, with apathy symptoms and opening of the subsequent members and ataxia or lack of coordination of the movements, giving to the animal a rack aspect, following by exhaustion when falling to the ground.

In Brazil, the hipocalcemia, also known as fever of the milk, postpartum paresia, obstetric paresia, fever vitular, eclampsia, paresia puerperal, apoplexy of the parturiente, postpartum coma, collapse puerperal is a disease little studied in spite of the tendency of substantial increase of his/her presence in systems more production tecnificados. Although he/she has linked denominations to the fever most of the picture is of hypothermia. More recent studies, in areas with specialized flocks, they have been showing an incidence of the hipocalcemia around 4,2%. For some authors, in the last two weeks pre-childbirth and until the third postpartum day the cows milk pans present certain difficulty of maintaining the normocalcemia. Even cows hígidas present a small temporary hipocalcemia, that he/she begins in the last week pre-childbirth and he/she extends until the 4th or 5th postpartum day. Some factors favor the emergence of the hipocalcemia:

1. Race. the cows Jersey is more subject to the disease for they present larger colostro production proportionally.

2. Feeding. the cows overfed in the dry period present larger depression of the appetite in the postpartum period, reducing the global amount of available dietary calcium. On the other hand, the rich feedings in fats no complexadas with calcium and zinc can reduce the readiness of the dietary calcium, predisposing the emergence of the illness or the exclusive ingestion of rich diets in oxalatos.

3. Age. the old cows present, progressively, smaller capacity of bone reabsorption and of intestinal absorption of calcium, besides they present the most depressed appetite.

4. You milk of colostro. they demand from the females 2,5 times more calcium than it milks her/it of the common milk, crossing the capacity of the intestinal absorption of this element. Like this, in agreement with the intensity of the you milk, there will be the incentive for the female to produce more colostro, rich product in all of the elements of the mammary secretion.

5. Use of medicines. mainly the antibiotics that contain aminoglicosídeos (deidro-estreptomicina, gentamicina, neomicina, among others), for road parenteral reduce the readiness of free calcium in the organism of the cow for up to six hours for if they call temporarily to that element mineral existent ionizável in the blood.

6. Presence of the potassium. very rich soils in potassium can take to the accumulation of substances denominated oxalatos on the part of the grass, the ones which, being completely transformed in the rúmen, they tend to reduce the dietary readiness of calcium for the animals.

As the main reason of the hipocalcemia is the low tenor of calcium in the blood, it is necessary to accompany as that element acts in the organism of the cow, his/her absorption and like this to determine the alimentary handling to be used. The specific prevention of the hipocalcemia should be begun exactly 30 days before the childbirth, for the incorporation of a diet aniônica, aiming at to provide a ânion (I chlorinate and sulfur) excess in relation to the cátions (sodium and potassium). Like this, the call differentiates dietary (DCAD) cátion-ânion will be negative. The ideal is that that negative swinging is among -30 to .100 matter mEq / kg dries. The offer of a diet aniônica with superior values to .200 matter mEq / kg dries is contraindicado, because it reduces the production of the future nursing, it reduces the ingestion of foods and it predisposes the animal to the syndrome of the greasy liver.

With the consumption of the diet aniônica (DCAD negative) there will be gets better of the readiness of calcium, favoring the bone reabsorption of that element. With that, it is waited for the decrease of the hipocalcemia, increase of the production of milk and better reproductive acting. Negative DCAD is also important when the low energy takes to a severe loss of weight of the animal. More recent studies have been demonstrating that dry cows should receive diets aniônicas, while cows in nursing should be fed with diets catiônicas.

Tends in view the difficulties to formulate a ration with low levels of calcium. less than 0,5% of the matter dry. and as in the effect of the diets aniônicas, the prevention of the hipocalcemia is more efficient in combinations with high levels of dietary calcium, a diet is recommended with approximately 150 g of calcium for cow a day in the final period of gestation.

The monitoramento of the action of a diet aniônica can be made through the pH of the urine, which should be between 6,0 and 73. To use that method, it should be suppressed in the pré-childbirth the bicarbonate of calcium and the carbonate of calcium of the feeding, because they reduce the action of the diets aniônicas and they increase the sanguine pH. It should be emphasized that the diet aniônica is restricted to the period specified pré-childbirth. Already in the beginning of the postpartum, the diet returns the being catiônica (approximately 225 matter mEq / kg dries) or the ingestion of foods and milky production will be affected. The diets should also have until 60 g of match for cow a day.

As treatment of the affected cow if it recommends the administration of until a liter of calcium for the road endovenosa, and part of this amount to be administered by the subcutaneous road. This treatment can be repeated in function of the persistence of some symptoms.