Milk Fever

[nz dexter]

I lost a 7 year old cow this morning to milk fever. It was the 3rd time she went down with it, she would get treated and be good for 2 days then go down again. This morning she was still alive but by the time I got help to help me treat her she had died. Is it genetic? We also lost her mother last year approx 6 weeks prior to calving with it too. If it is genetic I am stuffed as the vast majority of my herd have decended from the 1st one to die last year. It is so disheartening to loose them, they are my pets. Is it common in Dexters? Alot of Dexters that I have seen are over weight and this apparently is a precursor for it, I would not have said that the one that passed away this morning was over weight wereas her mother was. Next year I will have to give them some silage or something with some of the powder stuff in it. What do other people do to prevent it in the first place as I do not want to loose any more of my precious girls.

[moomin]

Sorry to hear your sad story.
Milk fever can run in families but you can do a lot to prevent it. My vet says there has been a lot in our part of the U.K. this year [I had two go down, first time in 30 years, they were different cow families by the way] due to unusual growing conditions.
Is your grass growth fast at the moment, have you had a lot of rain and warmth?
Preventitive measures for the rest of your girls - Feed some hay and put out a dry cow feed block, must be a dry cow one with a high level of magnesium.
Best of luck.

[Duncan MacIntyre]

I too am sorry to hear you are having such a terrible time. On the genetic front I am not sure that the tendency to Milk Fever is itself inherited, but because it tends to affect high yeilders it may appear that way as the highest yielders in a herd may well be related. As Di says there is quite a lot you can do to prevent it. Older cows are more prone to it because their bones become more "solid" as it were, and it is more difficult for them to withdraw calcium at short notice to maintain blood levels at calving. Contrary to what might seem logical keeping calcium intake during the dry period relatively low helps as they are less dependent on daily oral intake and the mechanism to withdraw it from bone is in working order. Long dry periods are not a good thing as the calcium metabolism has had too long a holiday. The level of magnesium can also be quite an influence, and herds of UK dairy cows with high incidences of milk fever particularly in Autumn often have marginal magnesium levels. I am wondering if this may be the case with your herd since you say the older cow was lost 6 weeks before calving. In my experience it is most unusual to see uncomplicated milk fever at that time. I am asuming thas as "NZ Dexter" you are in New Zealand so not in Autumn as we are at the moment.

In the UK this autumn I think there has been a very high incidence of milk fever and other metabolic disturbances, probably due to the deceptive nature of grass at this time of year - full of green and water and not nearly enough energy for the modern dairy cow.Holstein types nowadays in UK are struggling to get enough out of a bellyful of grass for their level of production and it is becoming increasingly necessary to suppliment grazing all year round. I have the impression that in NZ different genetics have been pursued and herds are much more geared up to cheap milk from grass. Many of these worries should not apply to the Dexter in either hemisphere of course.
Di offers some good advice - look at fibre intake and suppliment this with straw if grass is lush and wet in spring or autumn, and watch magnesium levels.

Duncan