Vet on Call: Science and art behind raising quality calves for the best herd

Willy Kirui feeds his eight-month old calves at Tergat Farm in Elburgon. Feeding of the calves should be adjusted in quantities and the composition of proteins and carbohydrates as the calf grows into a yearling and then a bulling heifer. PHOTO | JOHN NJOROGE | NMG

What you need to know:

  • Calf rearing is a science, an art and a passion. It is a science because a farmer needs to understand the biological requirements of the calf and the cow.
  • You must ensure the calf suckles or is fed at least four litres of colostrum in the first 24 hours.
  • A good calf is also all about insemination.
  • A calf should be borne with a weight that is 6 per cent of the mother’s weight.

There is a saying that a cattle herd without calves is a dying herd. I could, therefore, understand when Wachira called me the other day from Kirinyaga sounding frustrated with his dairy venture.

He explained that he had started with 10 Friesian cattle five years ago and all along, he had only survived two heifer calves to adulthood.

He had had good luck with heifer calves. Overall, his cows had given birth to more heifers than bull calves.

Wachira’s frustration was that all the calves except two had died before attaining the age of six months. Last year, he had five calves but at the time of calling, only two remained. “I am sure even these will soon die,” he had told me in resignation.

Upon probing, Wachira explained that veterinary service providers had said the calves died of pneumonia and diarrhoea. I asked him to send photos of his calves feeding and a photo of his dairy unit capturing details on feeding and the housing.

The photos revealed the problem. The calves that were about four months were fed on overgrown napier grass, rice straws and banana stems. These materials barely supply the calves with their body maintenance requirements.

The calves were kept on an earthen floor that was visibly wet. From the calf-pen location, the calves were in contact with the adult cows.

I could also see some water pools on the floor of the adult cow pens. Both the cows and calves had dirt smudges on their coats. The calves looked much smaller than the expected size for their age.

With such calf management, there was no way Wachira would have escaped his predicament. His dairy cattle management practice was designed for failure on all fronts. I asked him about his milk production per cow, per day.

“The best is eight litres,” he replied. From my visual evaluation of his cows, they should be able to give him a minimum of 15 litres if well-managed.

Wachira’s case is not isolated. I recall visiting a farmer in Kiambu two weeks ago and he said he had only survived three calves out of eight in the last three years.

Again, his main problem was pneumonia and diarrhoea. These two disease complexes are the main killers of calves where husbandry is insufficient.

Unfortunately for Wachira, his two calves died a week after our discussion while he was in the process of rectifying his cattle management practice.

So what is the magic in rearing calves? Honestly, there is no magic, but calf rearing is a science, an art and a passion.

It is a science because a farmer needs to understand the biological requirements of the calf and the cow. Activities on the farm, especially feeding the calves, require the farmer to do a lot of calculations and measurements to get it right.

PROCESS OF RAISING A CALF

The good news though is that we, the scientists, have collapsed the science of calf rearing into figures and activities that the farmer can carry out without having to do the complex calculations themselves.

All you have to do is follow defined activities and measure the results against set benchmarks – and the calf will grow to become the cow you desire.

To have a good calf, it all starts at insemination. The cow should be given well selected semen of high quality. The farmer should instruct the inseminator to use semen with the qualities he desires in his cows as elaborated in my article in Seeds of Gold of March 17.

The pregnant cow should be fed well, given vaccinations, dewormed and treated promptly for any sickness to protect the developing calf and give it the immunity it needs when it is finally delivered.

At seven months of pregnancy, the cow should be dried to give the udder the opportunity to prepare colostrum and milk production for the calf when it is born.

The cow must be fed well with food high in energy, protein and vitamins in a process called steaming.

The calf should be born in a clean, quiet place and removed from the mother to a clean warm pen away from adult cattle soon after birth or within 24 hours. The calf must not mix with other adult animals to prevent infections.

Mr Kirui attends to his calves in his farm in Elburgon. Calves should usually be born in a clean, quiet place and removed from the mother to a clean warm pen away from adult cattle soon after birth or within 24 hours. PHOTO | JOHN NJOROGE | NMG

Now that you have a good calf at birth, that does not guarantee you a good calf to adulthood. You must nurture the heifer calf to be a dairy cow with a long productive life.

Calves are born with very low immunity but nature corrects this soon after birth by providing immunity through colostrum.

Colostrum in the first 24 hours has the highest level of immune chemicals, called immunoglobulins, which the calf requires.

In addition, the calf’s intestines have large gaps in their walls that allow the immunoglobulins to quickly be absorbed into the blood. This opportunity closes within the first 72 hours of the calf’s life. You must, therefore, ensure the calf suckles or is fed at least four litres of colostrum in the first 24 hours.

Two of the four litres must be consumed within the first six hours of life. Also, ensure that the calf continues feeding the colostrum to its fill for the first 72 hours of life to enable maximum uptake of the immunoglobulins. Your calf is then protected from the diseases the mother has been exposed to.

A calf should be borne with a weight that is 6 per cent of the mother’s weight. When calves are well-fed and managed, they double this weight by the time of weaning at 56-90 days, meaning they will have attained 12 per cent of the mother’s weight at birth.

FEED THEM ON HIGH PROTEIN DIET

Therefore, calves should be weaned when they have doubled their weight and not when they attain a set weaning age.

To attain the weaning weight promptly and build the calf’s resistance to infections, feed the calf 20 per cent of its body weight in two or three portions.

This translates to 6 to 10 litres per day for calves between 30 and 50kg. Where milk is required for sale, the calves may be fed on high quality milk replacers after the first 10 to 15 days of being on milk.

The calves should be introduced to high quality starter feed within 10 days and roughage such as grass or hay from 17 to 21 days to encourage the development of the rumen.

Hay and roughage should, however, be limited as too much of it causes pot bellies in calves. Good calf starter feed should have minimum 18 per cent protein.

When calves are young, they have a structure called the oesophageal groove that connects the mouth directly to the abomasum (the simple stomach that digests milk).

The groove closes at about 20 weeks of age and it is no longer useful to feed the calf milk after that age because the milk will be nutritionally destroyed in the rumen.

Calves that are well-fed have a shiny supple coat and all their prominent bones are well-covered with muscle. They are a joy to look at and even touch.

Once you wean your calves, you should house them in groups of the same age and body condition and feed them on high protein diet.

Boma Rhodes grass hay, lucerne hay, high quality silage or good clean kikuyu grass; coupled with commercial calf concentrate feed from reputable companies will put your calf on the road to being your desired dairy cow.

Feeding of the calves should be adjusted in quantities and the composition of proteins and carbohydrates as the calf grows into a yearling (9-12 months) and then a bulling heifer (12-15 months). The protein requirements decrease as the calf gets older.

At all times, a very high level of hygiene must be kept in the rearing of calves. Prompt treatment must also always be given by a qualified veterinary service provider when the calves get sick.