The newborn female calf should become a milk-producing cow in about 2.5 years’ time. However, calves may die and this mortality means a loss of money. Far worse is morbidity, the chronic disease status of calves resulting in stunted animals. Morbidity affects all aspects of the animal during its entire life: its growth, the age of first calving, milk production and calving interval.
Proper young stock rearing preventing mortality and morbidity is extremely important for the economic situation of the farm. This starts with the care of the cow around calving. The next step is to help the calf, usually a monogastric animal at birth – to become a ruminant. A ruminant has four functioning stomachs, while in the recently born calf only the real one, the abomasum, is developed. The other three stomachs, especially the rumen, develop when the young animal eats roughage. This process takes about 8 to 10 months.
Parturition in cow: Calving
A pregnant cow will give birth to her calf 9 months after the last successful service. The unborn calf grows fast in the last two months and the milk producing tissues in the udder are renewed. It is why the cow has to be dried off 2 months before the expected calving date. The cow should be observed regularly a few days before calving and, if possible, be separated from the herd, preferably in a clean, roofed place with dry bedding and without obstacles that might cause injury.
At the start of delivery the animal becomes restless, lies down and stands up again, and attempts to urinate. The uterus starts contracting which is not yet visible. The appearance of the water bladder is the first real sign. In a normal delivery the calf’s front legs and mouth appear first. Once the head is born the rest of the body will follow, only the hipbones may cause some delay. If it takes too long, pull on the front legs, but only when the cow herself is pushing.
It is best to keep an eye on the cow but let her do the job. If assistance at calving is really unavoidable, make sure that your hands are washed and clean and wash the vulva of the cow before starting. In case of doubt or lack of experience, call the vet or an experienced person.
The afterbirth or placenta should be expelled within 3 to 4 hours. If this does not happen within 12 hours, call for expert help. Do not pull or put a weight on the afterbirth, this may damage the cow’s uterus and cause serious problems. Allowing the calf to suckle directly after birth stimulates the expulsion of the placenta.
Calf rearing
A newborn calf needs milk for about 3 to 4 months. After weaning, the calf can do without milk but it still needs high quality feed to stimulate its growth and development. The period after weaning is often the most difficult, especially if high quality feed is not available or is considered too expensive. Calf mortality, however, is highest during the first 3 to 4 months.
The first days
Right after birth the umbilical cord should be disinfected with a solution of iodine. A newborn calf does not have any resistance against diseases or parasites, so it needs good care, proper housing and adequate nutrition to prevent it from becoming ill. Newborn calves should be housed in an individual calf pen. Assure a dry floor with bedding or a slatted floor and no draught of cold air. After 3 weeks, calves can be housed in a group.
The newborn calf needs colostrum as soon and as much as possible, preferably within half an hour but at least within 2 hours after birth. ‘Colostrum’ is the milk the dam produces during the first 3 days after calving. Colostrum contains a lot of antibodies and it gives the calf so called ‘maternal immunity’. Some farmers allow the calf to stay with its dam for 2 or 3 days to get the maximum amount of colostrum. The problem is that it may be difficult to teach the calf to drink from a bucket thereafter. Other farmers milk the cow 3 to 5 times a day and feed the colostrum immediately to the calf, about 0.75 to 1 kg each time. This is important for building up immunity as soon as possible. Maternal immunity lasts for some 2 to 3 months and within this period the calf has to build up its own immunity. Best is to allow the calf some exposure to pathogenic organisms and parasites. Caution: make sure it is only a light exposure!
Feeding till weaning Milk is a complete and natural feed for the young calf that needs about 10 % of its body weight per day during the first 3 to 4 months of its life. Too little milk will hamper the development of the calf, too much may cause diarrhoea. Stick to the right amount and the calf will make a good start. To train the calf to drink from a bucket, let the calf suckle on a finger and lead it towards the milk in the bucket; after a few times it will drink all by itself. Clean buckets and strict hygiene are required; otherwise the calf will get diarrhoea.
From the second week onwards a small portion of concentrates and some roughage should be offered. A special calf concentrate is preferable but any good concentrate will do provided that it does not contain urea and cottonseed cake. At the beginning, the concentrate can be given in the same bucket as the milk. Once the calf starts eating it readily, it should be given in a special feed trough.
Roughage, preferably hay of a good quality, will stimulate rumen development. It can be tied with a piece of rope to the side of the pen when the calf should start eating it suckle-wise. Once the calf begins to really eat the roughage it may be given in a rack and ad libitum. Fresh roughage should be supplied, preferably twice a day. Make sure the calf has water available at all times and, at a later stage, some minerals.
Although very detailed feeding schedules exist, an effective and simple system is to give the calf 2 kg milk in the morning and 2 kg in the afternoon for 12 weeks at least, or about 300 litres in total. This is a minimum, feasible only if the calf consumes an adequate amount of concentrates. If concentrates are not available, more milk per day must be given for a longer period. At weaning, calves of improved breeds (500 kg mature weight) should weigh at least 70 kg and consume 1.5 kg of concentrates per day. After weaning, the calf still needs good quality roughage and concentrates to continue its development. Often concentrates are considered too expensive for calves, but remember that the nutritive value of 1 kg good quality concentrates is equal to that of some 3 to 4 kg milk.
Bull calves
On most dairy farms bull calves are neither used nor needed. Rearing them costs money, so unless needed to stimulate their dams’ milk letdown, sell or slaughter them as soon as possible.
Suckling
Many local and crossbred cows will not let down their milk without their calf being present. This does not necessarily mean that the calf has to suckle first, often its close presence will do. If this is the case the cow will stop producing if her calf dies. Therefore try milking the cow without the calf. Some farmers allow the calf to suckle the last milk for 10 to 15 minutes. This may help to reduce mastitis, but as the last milk contains the most fat, the calf may get too much fat. Better leave (part of) one quarter or teat for the calf, but not always the same teat.
In some areas milk is only collected in the morning in which case the calf can join its dam for suckling after the morning milking till midday. From then on until the next morning milking, calf and dam remain separated.
Here are some points to bear in mind when calf rearing:
• Immediate provision of colostrum to the newborn calf is essential.
• Feed an adequate amount of milk from a clean bucket, right after milking the dam.
• Introduce special or good quality concentrates at about one week of age. Start giving roughage during the second week, preferably good quality hay.
• Make sure the calf pen is dry, draught free with a slatted floor or adequate, tick free, bedding.
• Provide the calf with fresh and clean water from early age onwards.
Young calf rearing
After weaning at an age of 3 to 4 months, many calves are fed on roughage alone, which is not enough for adequate growth because their rumen is not yet fully developed. Generally, roughage needs to be supplemented with calf or young stock concentrates till the age of 1 year at least, though this depends on roughage quality and season. With good quality roughage, a growth of 200 to 300 grams per day is feasible. However, the required growth for a heifer to conceive at about 20 months is 450 to 500 grams per day, necessitating the providing of supplements of at least 1 kg of concentrates per day.
Many farmers give the best quality roughage to their dairy cows and the young stock gets what is left. This hampers their development and they might remain stunted for the rest of their lives. Young animals need adequate nutrition and this investment will be repaid once the animal starts producing milk.
A well-developed heifer can be serviced at about 20 months of age and in this way she will calf-down at about two and a half years or 30 months. The pregnant heifer should grow at least 500 grams a day and this cannot be achieved on the basis of roughage alone, so she needs supplements as well. Any setback in nutrition and health will affect her development, her pregnancy and her future milk production. Such a setback is difficult to compensate later on, the animal will remain a poor producer for the rest of her life.
Once the heifer has calved and started her productive life, rearing is not yet complete. She will continue growing and developing during the first lactation. The extra feed required, the ‘youth allowance’, is about 20% TDN and CP above the daily maintenance requirements. This youth allowance must be taken into account to enable the cow to develop her production potential. Cows reach full maturity at 4 to 5 years of age, depending on the breed.