Replacement heifers at joining

What about Mineral Supplementation and Fertility? Response Trial #2

You may have seen last years post about our response trial comparing mineral supplementations. We compared Multimin to Cobalife Se to see if there was any difference in weight gain in our young cattle over the winter. As both products delivered a similar amount of selenium – our main deficiency – I felt the trial was an opportunity to measure any difference in response to the other possibly useful ingredients: copper (from Multimin) and the B12 (from cobalife). There wasn’t. Unfortunately, I didn’t have an untreated control so I can’t tell you if the Se made a difference to weight gain.

The area Sales Manager from Virbac (Multimin) saw the post and got in contact with me to discuss the trial and made the point that Multimin makes no label claims about weight gain. Fair point. Multimin is recommended for fertility and immunity. I agreed to run a second trial with our commercial maiden heifers to see if there was any response in the form of conception rates or pattern. There was! 5.5% increase in conception rate in the heifers treated vs untreated (control).

The Nitty Gritty

Similar to our previous response trial, we simply split the treatment groups by their management tags – odd and even. Treatment and weights were collected on 15/10/2020 – 8 days prior to joining. Ideally, the supplementation would have occurred a month out from joining but our timing was determined by their Pestigard vaccination schedule.

As it happens, the odd tags were the same group treated with Multimin back in June (07/06/2020). The even tags had received Cobalife back in June so both had similar histories of Se supplementation.

Preg Testing (with foetal aging) occurred on 27/01/2021.

The Results

Comparison of conception rates by cycle (absolute values)

There was no difference to the average weight of each group nor to the rate of weight gain over the trial period.

There wasn’t much of a pattern in conceptions… i.e. there wasn’t more early pregnancies in the treated group. Virbac technical staff suggest this may be a result of administering the treatment 8 days out rather than the recommended 30 days.

Comparison of conception rates per week of conception (absolute values)

Conclusions

So what can we conclude from this trial? I know from past incidence of white muscle disease and recent blood tests in our mature cow herd that our cattle are deficient in Selenium (Se). Multimin delivers enough Se for approx 3 months in the form of sodium selenite. Virbac tell me that sodium selenite is available to the animal more quickly and at higher level of availability than the barium selenate found in Selovin LA.

Is it repeatable? Mineral deficiencies are likely to vary from year to year depending on the season. I’ll probably run another trial next joining to confirm, but given what I know about the lack of Se in our environment, and the relatively low cost and ease of supplementation, I’m pretty comfortable adding Se supplementation to our annual animal health program.

Future Trials

Recent blood testing of our mature cows suggest that copper, zinc and manganese are within target ranges so I suspect that supplementing these other components of Multimin is not of any value to our enterprise. Other products with sodium selenite may prove more economical – perhaps worth trialling next joining.

The other label claim of Multimin that has got me thinking is that it promotes immunity. Specifically, I’m considering whether I can use mineral supplementation of calves to reduce the level of damage from pink-eye by boosting the strength of their immune response to eye injuries. Let me know if you’ve tried this? I’ll supplement the calves at weaning this year but ideally, they’d have the supplements on board well prior to weaning. Next year I’ll supplement at the second 7-in-1 vaccination in December.

Conflict of interest statement

For this (2nd) response trial Virbac supplied us with 100ml of Multimin free of charge. The data from this trial has been shared with Virbac.

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