8 Preventive measures Calcium bolus Administration of a calcium bolus to bridge a calcium deficiency • At least 40 g of available calcium should be administered per dose. If the calcium content per bolus exceeds 40 g, one bolus per dose is sufficient. On average, two calcium doses are sufficient. • Use only products that are gentle on the mucous membranes. Calcium chloride is corrosive! • If calcium carbonate is used as the calcium source, it must be noted that the bioavailability of calcium is only approx. 75 per cent. Liquid calcium Administration of a liquid calcium supplement to bridge the calcium deficiency • At least 40 g of available calcium should be administered per dose. If the calcium content per bottle exceeds 40 g, one bottle per dose is sufficient. On average, two calcium doses are sufficient. • Use only products that are gentle on the mucous membranes. Calcium chloride is corrosive! • If calcium carbonate is used as the calcium source, it must be borne in mind that the calcium availability is only approx. 75 per cent. • The more the cows like the taste of the product, the easier and safer it is to administer. Ca Ca Ca Ca-Binder Calcium binders during the last 2 weeks before calving • Feeding calcium binders reduces calcium uptake in the cow’s body. A restricted calcium supply during the dry period can help prevent milk fever. • However,if the ration for dry cowsconsists of a high proportion of potassium-rich grass silage or potassium-rich hay, this measure is not sufficient. • The calcium binder binds calcium in the animals’ digestive tract. The bound calcium is excreted and only the unbound portion enters the bloodstream. This produces the same effect as a low-calcium feeding. • Prerequisites for correct use are a ration calculation, close monitoring of feed intake and immediate discontinuation of calcium binders after calving! Vitamin D3 s.c. or i.m. (subcutaneously or intramuscularly) Vitamin D3 injection • As this is a veterinary medicinal product, its use must be discussed with the vet. Calcium s.c. (subcutaneous = below the skin) Subcutaneous injection of calcium • As this is a veterinary medicine, its use must be discussed with your vet. Acid salts Acid salts during the last 2–3 weeks before calving • Feeding acid salts reduces the DCAB (cation-anion balance) in the feed ration. The aim is to achieve a low blood pH level prior to calving. This negative metabolic state reduces the danger of milk fever. This can be achieved through feed rations with a negative DCAB. • Prerequisites for correct use include precise ration calculation, regular urine analysis, close monitoring of feed intake and immediate withdrawal of the acid salts after calving. Low-potassium and low-calcium feed ration for dry cows • A feeding low in calcium and potassium during the last 3–4 weeks before the expected calving date reduces the danger of milk fever. • However, if the ration for dry cows consists of a high proportion of grass silage or hay, this is usually not feasible. • For this measure to be successful, analysis results for the forage used and precise ration calculations are essential. Dairy cow – milk fever Risk factors for milk fever • High milk yield • Older cows that have calved three or more times • Potassium-rich grass silage • Cows that have previously suffered from milk fever
RkJQdWJsaXNoZXIy MTUxMjAyMw==