Milk fever, or hypocalcaemia is a metabolic disorder (calcium deficiency) that sheep, cattle and goats are susceptible to, usually in late pregnancy, when the draw on their calcium reserves is very strong. It is usually seen in autumn and spring, when there is a flush of rapidly growing green feed in the paddocks, which is high in water content and low in nutrients.
Often sheep in the paddock can have a very mild case and not be showing any symptoms. It is not until you try to move them that you aggravate the symptoms, and notice it. This was what happened to us last week. It has been SOOOOO dry up until the last couple of weeks, and we have been feeding out a lot of grain. Then with the rain we have had a fabulous greening up of our paddocks.
We always crutch(shear their rumps to minimise the risk of a spring fly attack, and around their udders to make it easier for their lambs to find the teats) our sheep about 4-6 weeks out from lambing, and this was last week. At the same time they get their annual vaccination against diseases such as blackleg, pulpy kidney and other such clostridial diseases, which can wipe out a flock very quickly.
So whilst mustering and yarding the sheep I noticed the odd one showing signs – weak appearance, stilted movement, and even the one or two going down. Once they go down, they won’t get up until treated.
Luckily I did have treatment on hand, a subcutaneous injection of a 4in1 solution of calcium, magnesium (often these two are related in deficiencies around lambing time) phosphorous and glucose. The ones that I treated early got up almost immediately, it is amazing how quickly it works. However one went down in the yards over night, while waiting to be crutched, and she took two or three doses. I ended up leaving her in the yards for a couple of days, so I could monitor her, make sure she was eating and drinking properly before taking her back out to the paddock.
I have since put out lick tubs for each mob, and am supplementing their diet with bales of hay. The lick tubs contain a 75:25 mix of salt and stock lime. The salt is to make it taste nice (???) and the lime is to combat the calcium deficiency. The hay is just to offer an alternative to the rich lush green feed which is low in calcium. I also took them back to their paddocks in stages after crutching, so that they weren’t walking the whole way in one go. Their first stop was at our large dam paddock where they had only good quality hay to eat for 24 hours, to build up their energy reserves, before heading the rest of the way.
I strongly believe that the ewes need to be crutched at this time – for their own benefit, to minimise the risk of them from getting fly-strike in the spring and also to give the new born lambs every chance of finding the teats easily. However it is always a balancing act, and needs to be managed very carefully to combat the Milk Fever we faced this year, and also other metabolic disorders such as grass tetany (magnesium deficiency) and twin lambing disease (general energy deficiency). We have been very lucky in the last few years, with little to no issues arising. This year the seasonal conditions were against us.