Cornell University tested the efficiency of a calcium binder (X-Zelit®) for preventing hypocalcemia. Feeding low level calcium in the prepartum diet has shown to be effective in improving the calcium level at calving. However, as this is difficult to obtain using the commonly used feeds, binding the dietary calcium using X-Zelit can mimic the low calcium approach. Preliminary results from the trial were presented at the annual Cornell Nutrition Conference 2017. The overall conclusion was that X-Zelit markedly improved calcium status during the periparturient period.
The trial.
The trial was performed at Cornell University during the spring of 2017. 55 multiparous cows were assigned to either the control or experimental (X-Zelit) group. In the experimental group, 500 g/d of X-Zelit was supplemented during the last 3 weeks prior to calving. The DCAD level of both rations was 14-15 mEq/100g.
The calcium level for the two groups is showed in figure 1. The figure shows that the calcium level was overall higher for the X-Zelit group compared to the control group.
Figure 1. Evolution of calcium in the peripartum period.
The values of plasma calcium were higher for the X-Zelit group during the pre- and postpartum period. It took around one week before the calcium level of the control group reached normal levels. The higher calcium level around calving shows that the cows own defense mechanism for preventing low calcium levels has been activated by the X-Zelit treatment. High plasma calcium level around calving is important for the health and production level of the animals.
The improved calcium status did decrease the prevalence of the subclinical hypocalcemia. The threshold for subclinical hypocalcemia was set to 8.5 mg/dl (2.125 mmol/L). The incidence of subclinical milk fever was much lower for the cows on X-Zelit than the control cows.
The result shows that the X-Zelit product is a highly efficient product for preventing subclinical hypocalcemia in high yielding cows fed a typical US ration.
Figure 2. Prevalence of hypocalcemia (serum Ca < 8.5 mg/dL (2.125 mmol/L)) by sampling time point. Significant differences (P<0.05) within a day are depicted with an asterisk.