Calcium Binder X-Zelit Beats DCAD
Will Tulley reports on the latest trial data, proving X-Zelit to be more effective, providing more health benefits, improved fertility and milk yields than DCAD.
America has long since been seen as the home of DCAD with producers carefully selecting the right forages and balancing nutrients in order to prevent clinical and sub-clinical milk fever. However, it seems the tide is turning with the Americans and indeed other countries across the globe, now looking towards the calcium binder X-Zelit to prevent clinical and sub-clinical issues. A number of trials both in the USA, including this one in Kansas and others from Cornell University, as well as in Australia, have shown the superiority of the calcium binder in maintaining blood calcium levels post calving.
The latest trial was conducted by Kansas State University, on a 5000-cow commercial dairy herd comparing a negative DCAD and an X-Zelit close-up dry cow feeding strategy, in a side-by-side study. First calving heifers and older cows were randomly assigned to be supplemented with either BioChlor (DCAD -106 meq/kg) or X-Zelit (500 grams per head daily) in an approximately 4-week transition period. In a subgroup of cows, blood samples were collected at 0, 48 and 72 hours relative to calving to determine calcium, phosphorus and magnesium status.
Both treatment diets contained the same ingredients except for the inclusion of either BioChlor or X-Zelit and there was a difference in dietary calcium concentration (2.53%: DCAD versus .57%: X-Zelit). Although still the subject of some debate, higher calcium levels are frequently used in negative DCAD diets. Cows in both treatments were similarly managed and KSU research staff were present daily to assist the farm crew in mixing the prefresh diets. Cows were monitored daily for diagnosis and treatment of any health disorders until 60 days in milk.
Trial results
Blood calcium levels were significantly higher for the X-Zelit fed cows at both calving and 48 hours post-calving (Figure 1, 2 and 3). Not only did the X-Zelit treatment have much higher blood calcium levels, but there was less variability for the X-Zelit cows compared to the negative DCAD cows (figure 4). There were also fewer cows with chronic sub-clinical milk fever in the X-Zelit treated group. Higher and tighter blood calcium levels are critically important to maintain optimal health and production during the first 48-72 hours post-calving.
Figure 1
Figure 2
Figure 3
Figure 4
Implications
This field trial data strongly agrees with the Cornell research trial (Kerwin et al., 2019) showing significantly higher blood calcium levels through the first 48-72 hours post-calving. The post calving blood phosphorus were also similar between this field study and the Kerwin data. In addition, chronic subclinical hypocalcemia (cSCH) cows are defined as cows that remain below the optimal blood calcium (8.5 mg/dl) level for the first 72 hours post-calving. There continues to more evidence emerging that cSCH cows are very high risk for reproductive failure, lower milk production and removal from the herd. The X-Zelit strategy provides the best opportunity for minimizing chronic subclinical hypocalcaemia at the farm level.
Using X-Zelit®, a calcium binding feed supplement stimulates the cow’s natural homeorhetic response allowing the cow to mobilise calcium from her reserves. This ensures that blood calcium levels remain at stable levels around calving, see below.
A similar study in Australia also compared X-Zelit to BioChlor on a grass-based system with a 160 cow robotic herd.
The results showed significantly higher blood calcium levels in the X-Zelit group.
Increasing blood calcium levels improves fertility and reproductive performance. In a study from Department of Livestock Health and Welfare, Institute of Veterinary Science, University of Liverpool it was shown that for every 0.1 mmol/l increase in blood Calcium there was a 33% increase in the chance of a cow being served and 16% increase in the change of conception.
In addition to Blood Calcium levels the Cornell research also looked at the impact on fertility. This study demonstrated that calving to conception was reduced by 19 days in cows supplied X-Zelit which had resulted in stable blood calcium levels compared to the control animals.
Transition Success
Achieving transition cow success is challenging for both cows and milk producers. A seamless transition into lactation is essential to maintain health and achieve expected production and financial goals. In contrast to the negative DCAD approach, the X-Zelit strategy allows producers to achieve optimal fresh cow blood calcium status with the convenience of feeding more home-grown forages instead of sourcing low potassium forages and routinely monitoring urine pH. Furthermore, higher blood calcium levels will reduce the need for supplemental calcium boluses, minimizing fresh cow treatments. Overall, the X-Zelit strategy will simplify the implementation and management of your pre-fresh feeding program while achieving transition success.
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