The Effect of Zeolite A Supplementation in the Dry Period on Periparturient Calcium, Phosphorus, and Magnesium Homeostasis

Abstract

One potential way of preventing parturient hypocalcemia in the dairy cow is to feed dry cow rations very low in calcium (<20 g/d); but, because it is difficult to formulate rations sufficiently low in calcium, this principle has been almost abandoned. Recent studies have shown, however, that it is possible to prevent milk fever, as well as subclinical hypocalcemia, by supplementing the dry cow ration with sodium aluminium silicate (zeolite A), which has the capacity to bind calcium. The aim of this study was to further evaluate the effect, if any, of such supplementation on other blood constituents, feed intake, and milk production in the subsequent lactation. A total of 31 pregnant dry cows about to enter their third or later lactation were assigned as experimental or control cows according to parity and expected date of calving. The experimental cows received 1.4 kg of zeolite pellets per d (0.7 kg of pure zeolite A) for the last 2 wk of pregnancy. Blood samples were drawn from all cows 1 wk before the expected date of calving, at calving, at d 1 and 2 after calving, and 1 wk after calving. Additionally, a urine sample was drawn 1 wk before the expected date of calving. Zeolite supplementation significantly increased the plasma calcium level on the day of calving, whereas plasma magnesium as well as inorganic phosphate was suppressed. Serum 1,25(OH)2D was significantly increased 1 wk before the expected date of calving among the experimental cows, whereas there was no difference in the urinary excretion of the bone metabolite deoxypyridinoline between the two groups. Feed intake was decreased among the zeolite-treated cows during the last 2 wk of pregnancy. No effect was observed on milk yield, milk fat, and milk protein in the subsequent lactation. The mechanisms and interactions involved in zeolite supplementation are discussed in relation to the observed improvement in parturient calcium homeostasis and to the observed depression in blood magnesium and inorganic phosphate.

Sodium Zeolite A Supplementation and Its Impact on the Skeleton of Dairy Calves

“…Sodium zeolite A (SZA) is an aluminosilicate that is hydrolyzed at low pH into silicic acid, amorphous aluminum silicates and aluminum [1]. Thus, by supplying SZA to the diet, an animal's gastrointestinal tract can break down this zeolite into orthosilicic acid.…”

Tissue Response to a Supplement High in Aluminum and Silicon

“…Sodium zeolite A (SZA) is an aluminosilicate that is hydrolyzed at low pH into silicic acid, amorphous aluminum silicates, and aluminum [1]. Thus, by supplying SZA to the diet, an animal's gastrointestinal tract can break down the zeolite into orthosilicic acid.…”

Zeolite A effect on calcium homeostasis in growing goats1

“…Therefore, several studies aimed at the reduction of Ca availability by adding the synthetic sodium aluminosilicate zeolite A to bind dietary Ca have been performed. In several studies, it has been shown that zeolite A supplementation during late gestation stabilizes blood Ca concentrations around parturition (Thilsing-Hansen and Jorgensen 2001;Thilsing-Hansen et al, 2002;Pallesen et al, 2008;Grabherr et al, 2009). …”

“…However, additional effects of zeolite A on plasma P (Enemark et al, 2003;Pallesen et al, 2008) and Mg (Thilsing-Hansen et al, 2002;Grabherr et al, 2009) as well as on urinary pH and renal excretion of minerals (Thilsing-Hansen et al, 2002) were also reported. Thus, the impact of zeolite A on mineral homeostasis appears more complex than just reducing the availability of Ca in the ration.…”