Reducing the risk of hypercalcaemia on farm with SoyChlor

8th March 2024


Morgan Sheehy: Hello, my name is Morgan Sheehy and I'm the Ruminant Director at Devenish and on my left is Stephen Leahy, Stephen is the Farm Manager at Tom O'Donnell's farm in Portlaoise and then over on my extreme left is David Atherton, over from the UK. David is with Thompson and Joseph.

We'd like to discuss about SoyChlor, so David briefly would you like to tell us what is SoyChlor and where it comes from?
David Atherton: Indeed Morgan yes, SoyChlor is a specialist concentrate for feeding to dry cows for the last 2-3 weeks before calving. It is a specialist concentrate that is designed to reduce the incidence of milk fever and hypercalcaemia which is a major nutritional problem in dairy cows.

It is produced in the US and was developed initially by Professor Jesse Goff who is a very well-known dairy researcher at the University of Iowa who has published more than 200 papers on close-up and dry cow nutrition over the last 30 years.

Morgan Sheehy: Thanks David. Stephen, you have been working with SoyChlor since 2013, isn't that right?

Stephen Leahy: 2010

Morgan Sheehy: 2010, so that's 13 years on SoyChlor. So, before you were using SoyChlor, what was the typical incidence of milk fever?

Stephen Leahy: Over the previous couple of years, we had an increase in the incidence of sub-clinical milk fever, and it hit 70% in 2009/10 and that year we started using SoyChlor and it eliminated all problems straight away and we never see any of those issues anymore.

Morgan Sheehy: I remember Stephen at the time you mentioned that it was one of only a few products that did what it said it would do on the tin.

Stephen Leahy: Yes, of all the products that are two products that spring to mind and SoyChlor is the number one that we've come across over the years and it does exactly what it is meant to do.

Morgan Sheehy: David, do you want to fill us in on SoyChlor and how it is used to reduce the dietary cation anion balance in the diet. And if you would like to explain what the dietary cation anion balance is in a nutshell.

David Atherton: Yes, hypercalcaemia that Stephen mentioned is calcium deficiency. For every one cow that goes down with milk fever that there are 10 with sub-clinical hypercalcaemia and that shows itself in terms of hung cleansings, dirty cows, extended calvings, cows that take a long time to come in to milk. It has long-term consequences in terms of depressed immunity. One of the risk factors for hypercalcaemia is potassium in grass silage and it is the major contributor to a parameter called the dietary cation anion balance, which is shortened to DCAB. The higher the DCAB number, the greater the risk of milk fever and hypercalcaemia.

Our aim is firstly to identify the potassium and DCAB level in the silage that is being fed as that gives us an indicator as to how much SoyChlor we need to feed in order to reduce the DCAB to a level which helps calcium utilization and availability in the cow in order to reduce the risk of milk fever and hypercalcaemia.

Morgan Sheehy: So normally what happens is that we go out on farm and take appropriate samples of all the forages and used detailed analysis to establish the DCAB and based on that we work on what levels of SoyChlor should be included in the diets. On average SoyChlor is included at roughly one and one and a quarter kilos in most cases and if we are using one kilo, David you might just tell us how that reduces DCAB by in the diet.

David Atherton: One kilo of SoyChlor reduces the DCAB by about 250 units. Typically a dry cow diet with average silage is going to have a DCAB level of around 350 to 400 and we really want to bring that down if possible to below 100 in order to be able to give calcium a real kick in terms of its absorption and utilization within the cow which is really what this exercise is all about. So 250 units reduction with SoyChlor.

Morgan Sheehy: So David, would it be true to say while a have two options to do a full DCAB and a partial DCAB, at farm level, to minimize monitoring on farm and to keep it simple for the farmers if we have consistent forages and consistent feeding system with appropriate feed space for the cow which is the case here Stephen. You are very adamant that you need a metre per cow in the close-up period. And the cow moves into the close up three weeks beforehand into the space and we work partial DCAB so it minimises work from the farmers pint of view and then it's a very straightforward system then.

David Atherton: Yes, its very important to have a practical system as Morgan says. DCAB can go negative which is what a full DCAB is and that is quite a severe stress on the cow and its quite difficult to implement from a practical point of view. A partial DCAB is looking at a DCAB of between zero to plus 100, somewhere in that area and that's something that very efficient and practical for reducing the risk of milk fever and hypercalcaemia.

Morgan Sheehy: And David I would say from the practical use and Stephen would have mentioned it several time over the years that other people try other products and there are other good products on the market, but one of the key distinguishing features of SoyChlor is that we keep the dry matter intake up in the cow. Do you want to comment on that as keeping the dry matter intake up as the cow approaches calving is absolutely crucial in minimizing post-calving issues.

David Atherton: Yes, absolutely. One of the key things that we tend to see as cows approach calving is of course the size of the calf pressing on the rumen starts to lead to a reduction in the dry matter intake of the cow and that's inevitable. Anything we can do to minimize that will ensure that the energy deficit that the cow will experience at calving is reduced. If the energy deficit gets too great, the cow tips into Ketosis and this is yet another set of metabolic problems that depresses immunity, milk production and fertility in the cow.

SoyChlor has a proven track record of supporting dry matter intake. It increases dry matter intake by about 1 to one and a half kilos per cow per day compared with the use of other anionic salt products. So this is a key feature and something that most of the farmers who use SoyChlor will comment on.

Morgan Sheehy: So Stephen, at farm level, the two big issues that you have always commented on is palatability and readily increasing dry matter intakes are the two outstanding features because they are issues in comparison to other products that distinguish it completely.

Stephen Leahy: Yes

David Atherton: Very much so, yes.

You can find more information on SoyChlor here.

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