Veterinary advice: Congenital JLD: Link to mouldy silage

A couple of years ago, a dairy client of ours had a peculiar but disturbing problem in his herd.
Veterinary advice: Congenital JLD: Link to mouldy silage

He asked me to look at a newborn calf that had difficulty getting up, and couldn’t stay standing if lifted.

The calf had no difficulty drinking milk. It appeared to be a healthy calf otherwise.

While all his calves appeared to be perfectly healthy, a growing number of them were on the small side.

The client obviously wanted to know the cause of these small calves.

Where do you start? Is it a genetic thing? Is it a virus?

On closer observation, some calves had short legs, which made them look smaller. A few had bowed legs. One had a shortened head.

Following a bit of research, things began to get a bit clearer.

In the 1980s, John Mee at Teagasc reported on animals with this condition known as CJLD (congenital joint laxity and dwarfism), or dwarfism. It was also reported in Scotland and Canada around the same time. Mostly it affected beef suckler herds.

Congenital means the condition is present at birth.

It is characterised by having a lot of movement in the joints of the lower leg, hence the difficulty in getting up and in remaining in the standing position.

These joints appear to be wobbly. The legs are shorter than normal, giving the dwarf-like appearance.

Unfortunately, once the calf is born with this condition, it is stuck with it.

No amount of feeding or medicine can change it.

Herds can have varying amounts of calves born with it, with some herds being devastated.

The worst affected calves have to be put to sleep. Others are so stunted it is impossible to sell them on the open market. A catastrophic situation!

A lot of possible causes have been put forward and discounted.

Researchers looked at BVD virus, a lack of vitamin D, manganese or iodine.

Was inbreeding a factor?

Following a lot of trials and discussion, it appears that mouldy silage has a major part to play in this condition.

The critical period of the pregnancy seems to be from about 100 to 230 days of gestation.

Cases seem to be more common in areas where silage has to be fed for a longer period, over the winter. It is also most common where silage is the only feed.

Originally, it showed on farms where silage was made without additives and, as a consequence, spoilage and mould was a major possibility.

The toxins produced by fungal growth (mycotoxins) have been linked to congenital defects in a number of species, as well as being the cause of abortions. The specific toxin that causes CJLD has not been identified.

Trials have showing that feeding an extra source of fodder can prevent this problem. Hay or straw with concentrates, when added to the silage, gave better results than by adding concentrates only.

John Mee recommended a number of steps to be taken.

First you should get your vet to confirm that CJLD is what you have on your farm.

Secondly you have to accept your losses for the present crop of calves, and plan to prevent it happening next year.

You need to replace up to 20% of the dry matter provided by grass silage by supplementing it with hay, straw, maize silage, or concentrates.

Obviously, mouldy pieces of silage should not be fed. John Mee also suggests supplementing with a range of trace minerals.

Every year is different, and the quality of the silage made every year is also different.

The weather we meet every year is different and animals are housed at different times. Sometimes they are fed baled silage outside.

I have not seen CJLD since, but you never know when you might see it again.

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