Tackling abortion in cattle
Losing livestock because of abortion frustrates farmers.
Maybe a sick bull and drought top the frustration list but farmers always have so much expectation from pregnant animals that they even predict how many calves or lambs will be born that season. I
t’s like counting one’s chicks before the eggs hatch.
Abortion is a recurrent devastating problem that most Namibian farmers are faced with.
Since we have discussed dystocia (difficult births) and the care of a newborn animal in the previous columns, let’s now look at the causes, prevention and management of abortions in cows.
Abortion in cows is defined as foetal (unborn calf) death and expulsion between day 45 and day 265 of pregnancy.
Most cattle herds suffer an abortion rate of 1-2%. A single abortion is thus no great cause for panic.
But if more than 5-10 of your 100 cows have aborted, there is a reason to be worried.
Imagine if a small-scale village farmer had 10 pregnant cows and four of those miscarried, it would be so painful and devastating. What could be the cause though?
There are various causes for abortion, including infectious and general diseases that cause high fever, genetic factors, too much heat, nutritional deficiency, various poisonings, as well as eating rotten or rotten feed and poor management of the herd.
In Namibia, there is a great concern over Campylobacteriosis (vibriosis), Trichomoniasis, Brucellosis (brucella), Infectious Bovine Rhinotracheitis (IBR) and Bovine Virus Diarrhoea (BVD) as infectious diseases.
Don’t worry much about the big names, we will discuss most of these diseases in detail in other columns but the general rule is; infected bulls may transmit it to the cows during mating.
Hence, bulls in infested herds should not be ignored, as the dreadful fact is that infected bulls may have no obvious signs of infection.
This takes me back to a commercial farmer in Gobabis area who was once looking for a movement permit to sell his bull to a village farmer.
He mentioned in passing to me that he had an ‘abortion storm’ and infertility problem on his farm. I was like, “In no way will our office give you permission to sell that bull before it is tested”.
The test came out positive for venereal diseases (spread during mating) and I had to advise him to immediately get rid of the bull since it was fit for a pot rather than for breeding.
Imagine the damage that bull would have caused the poor unsuspecting farmer.
This is why it is strongly advised to ensure that the bull you are introducing in your herd has been tested and certified by a veterinarian, paying more attention on the venereal diseases.
In ideal situations, it is also better to reduce close contact of your animals with other animals from another farms.
Unfortunately, this is almost impossible in our villages where there are no proper residential boundaries and fencing.
For infected cows, identify aborting as well as infertile ones and take them away from the rest of the herd.
In fact, one professor’s advice was to just get rid of any cow that has aborted for the next three years.
Take care to always remove aborted materials by burying or burning it immediately.
This will reduce the spread of the infection as well.
For proper diagnosis at the laboratory, wrap aborted foetus and after-birth in a plastic or any waterproof container and refrigerate them at +40C or keep in a cool place but do not freeze.
This can be taken to your nearest veterinary office or straight to the Central Veterinary Laboratory in Windhoek.
Provision of supplementary phosphorus, selenium, copper, iron and vitamins A and E has been proven to improve the conception rate as well as reduction of abortion.
(That’s another reason why I advocate for injection of multimin + selenium and multivitamins in cows before breeding and one month before giving birth).
Most of the toxic plants induce abortions; hence a proper history of the farming area might also help with the diagnosis.
Nitrite/nitrate poisoning has also been implicated in causing abortion and farmers are urged to regularly test their water.
Also, give particular attention to your feed storage as mouldy feeds may have mycotoxins that can cause infertility problems in your herd.
Another preventative measure that helps to reduce the abortion problem is to have proper hygienic and bio-security measures in the cow’s environment.
The use of contaminated grooming equipment or veterinary instruments has all been ‘incriminated’ in the spread of infections.
Adequate vaccination against infectious diseases causing abortion is very important.
Some farmers vaccinate yearly for IBR and BVD. It is compulsory for our farmers in Namibia to vaccinate their heifers between 3-10 months of age for Brucella.
Every farmer should keep good records of the reproduction of cows, including the number of abortions, conception rate and approximate breeding dates as well as any treatment administered.
This helps with efficient management of pregnant animals.
Finally, pregnant animals need to be kept separate from others to reduce stress. Give them that extra attention, especially the heavily pregnant ones.
I still remember with fondness one lucrative village farmer who once told me, “I treat my pregnant cows as I would treat my pregnant wife”.