Prevention of Milk fever : Nutritional Approach

The use of negatively balanced cation-anion rations during the late dry or prepartum period requires excellent monitoring and management. The cows must be separated from the remaining herd and fed a total mixed ration as a group. Lower plasma calcium (Ca) will stimulate the Parathyroid hormone (PTH) and 1-hydroxylase system to increase intestinal absorption of Ca and bone resorption –reduce incidence of milk fever. The incidence of milk fever was increased simply by increasing the potassium (K) concentration in pasture Diet high in K or sodium (Na) -alkalinize the blood decreased bone Ca resorption and renal production of 1, 25-(OH)2 vitamin D, increase incidence of milk fever. Inadequate supply of magnesium (Mg) in dry period reduce the ability of a cow to mobilize Ca at parturition. Anionic salts (-ve DCAD) prevents milk fever by acidifying the blood to restore tissue responsiveness to the PTH.


Introduction
the demand for calcium is greater than the supply in the blood, it causes the problem of milk fever, unless The art of feeding dairy cattle is rapidly the cow can rapidly mobilize stored calcium in her becoming the basic and applied science of dairy cattle body (e.g. in bones) to offset the situation.nutrition.Milk fever, a metabolic disease, affects high producing dairy animals usually within one or two Calcium Regulation Mechanism days after calving, resulting in a huge reduction in Cattle can absorb Ca from gut according to their milk production and thus becomes economically most needs.They are able to alter the absorption efficiency important.It is also known as periparturient paresis.
to meet changes in Ca requirement.When cattle It is estimated that this disease affects 3 to 8% of consume more Ca than needed, the proportion of Ca cows with some herds having prevalence as high as 25 absorbed is decreased (Horst, 1986).Ca is regulated to 30%.Symptoms appear when blood calcium levels by Parathyroid hormone and Calcitonin, which are are low; hence the synonym of milk fever is secreted from Parathyroid gland.The decrease in Ca hypocalcaemia.Incidence of milk fever is estimated to intake stimulates the secretion of parathyroid hormone nd be between 4-5% of 2 plus lactation cows and increases (PTH) from the parathyroid gland.PTH enhances with cow age.Economic losses due to medicines, renal reabsorption of Ca (Capon and Rosol, 1989) and veterinary services and reduced production exceed promotes the synthesis of 1,25-dihydroxycho-Rs.400 per cow (Mandali, 1999).Losses are also lelalciferol (1,25-(OH)2D) from 25-hydroxychoassociated with increased incidence of secondary lecalciferol in the kidney (Allen and Sansom, 1985).diseases, such as ketosis, mastitis, retained placenta, As result of stimulated 1, 25-(OH) 2D and PTH displacement of abomasum, uterine prolapse, limb secretion, bone Ca resorption and intestinal Ca injuries, and pneumonia can further inflate losses.
absorption increase (Horst et al., 1994).The action of Milk fever occurs in dairy cattle after calving PTH hormone is counteracted by calcitonin (CT), which is secreted by thyroid C cells.CT decreases the because of low blood calcium levels as a result of concentration of Ca in blood plasma by reducing the calcium moving into milk.There are about 23 grams of rate of bone resorption (Allen and Sansom, 1985).calcium in 10 liters of colostrums, and when this is Interrelationships between minerals can also added to the normal amount of calcium needed for influence the absorption and utilization of each other.maintenance, the needs of the cow can be more than 10 Ca has an interrelationship with phosphorus, times the supply of calcium in her bloodstream.When magnesium, manganese and zinc (Underwood and This method is used more commonly in Europe than in Suttle, 1999).Recommended optimal Ca:P ratio to the UK, and is more time consuming and has less reduce the incidence of parturient paresis were economic benefit than good dry cow nutrition.It is probably used in herds suffering from a high level of approximately 2.3:1.When the Ca: P ratio decreased metabolic disease around calving. from 2.3:1 to 1.1:1 the incidence of parturient paresis Whichever technique is used, good dry cow increases.
management is essential.The transition between dry A nutritional approach to managing milk fever involves monitoring specific elements in the diet.The and milking needs to be as seamless as possible.Also, common strategies to prevent milk fever can be whichever prevention route you choose make sure that all cows receives plenty of magnesium, as low divided into three, which are summarized below: Low calcium strategy (often with relatively magnesium intake is one of the most important causes high phosphorus): of milk fever.This is the strategy that's most commonly used in In recent years, dairymen have been able to the UK and is still effective on many farms.It works by reduce the incidence of milk fever and subclinical ensuring that the dry cow is mobilising calcium, so hypocalcemia during the early postpartum period by that when it switches to milk production it is better feeding adequate amounts of calcium, phosphorus, able to cope.A useful analogy is to think of the and magnesium.Earlier studies suggested that a lack lactating cow as an athlete, it's much more likely to do of available phosphorus in the diet of lactating dairy better if it has a bit of training before it needs to cows is the predisposing factor in milk fever.More compete.Low calcium in the dry period provides that recently, it has been shown that dairy cows on high training.
alkaline diets during the dry period are more prone to 2) DCAD strategy milk fever while an acidogenic diet tends to prevent This strategy was developed in the US in order to hypocalcemia and milk fever.Dietary cations combat the high potassium in their forages, which (positively charged) such as sodium (Na), and prevents the low calcium strategy from being potassium (K) are alkalogenic; dietary anions effective.Altering the balance of the diet by feeding an (negatively charged) such as chlorine (Cl), sulfur (S), excess of strong anions (primarily chloride and and phosphorus (P) are acidogenic.sulphide) would change the pH of the blood, if the body's mechanisms didn't prevent it.One of the Dietary Cation-Anion Balancing mechanisms that prevents this is the calcium Dietary cation-anion balancing is a new concept metabolism, thus feeding an 'anionic diet' is another that has received much attention recently as a way of training the cow before it starts milking.This nutritional tool for reducing milk fever in early can be very effective, but it is more difficult to lactation as well as improving health and production.undertake than the low calcium strategy (with which it The dietary electrolytes are balanced according to the mustn't be combined).Potential problems include low charges they contain.Because cations are positively palatability of some anionic salts and the requirement charged and anions are negatively charged, the ration for regular urine pH testing.If the DCAD strategy is is balanced to be either negative or positive.A not done correctly it can lead to significantly increased negatively balanced ration favors prepartum dry cows milk fever levels.
and reduced incidence of milk fever, whereas a 3) Drenching or pasting positively balanced ration favors lactating cows and Several commercial products are available for increased levels of milk production.That is, lactating boosting blood calcium.Best results are obtained if the cows do better with a positively balanced ration and first dose is given just before calving (usually around 8 hours before) with a second dose 24 hours later.This prepartum cows with a negatively balanced ration.
Mineral elements considered in cation-anion obviously requires calving to be accurately predicted.balancing are sodium, potassium, chlorine and sulfur.
the greater mobilization of calcium from bone stores.To create a well-balanced ration using the cation-anion Research has shown that cows fed anionic diets have approach, about 150 to 250 total grams of a combination higher blood calcium levels at calving. of compounds such as ammonium chloride, ammonium The cation-anion balance may have potential for sulfate, calcium chloride, calcium sulfate and magnesium improving milk yield in the subsequent lactation, and sulfate are needed daily per cow.The amount needed reducing the incidence of both retained placenta and of will vary with the concentration of potassium and milk fever.Most of the available research indicates sodium in the ration.Because anionic diets stimulate that diets which are acidogenic (negative cation-anion greater mobilization of calcium from bone, they balance) are beneficial to calcium absorption and in should not be fed the entire dry period.The anionic salts the reduction of the incidence of milk fever.The used in the prevention of milk fever are quite unpalatable feeding of such rations should be during the last 2 to 3 to dairy cows.As a result, they should be used with weeks of the dry period.
Nonlactating cows should be properly managed caution and mixed thoroughly in the dry cow ration.
A cation-anion balance is calculated by subtracting during the dry period to assure top production in the anion milliequivalents from cation milliequivalents subsequent lactation.Properly balanced rations (meq.).While several formulas have been used, the designed to avoid metabolic problems and fed during the prepartum period will assist the dairyman in following equation (Equation 1) is suggested for dry reaching his objectives.cows.Equation 1: Cation-anion balance = meq [ ( Na + K ) -