The calf is the foundation for any future cattle stocks and its care is crucial for sustainable animal agriculture and maintenance of good quality germ-plasma.
What happens during the first hour of life of a calf is critical to its health and, therefore, the calving environment must be conducive. The most critical period in a calf’s life is when they are weaning. The goal is to keep them alive, healthy and growing during this period.
Calves have special nutritional needs and if these are not met, the calf can suffer serious health issues immediately or later as a cow or bull. Make sure you are following a strict feeding schedule, especially when raising a newborn calf.
Colostrum
Colostrum is a milky fluid that comes from the udder of cows in the first few days after calving, before real milk appears. It contains proteins, carbohydrates, fats, vitamins, minerals and proteins (antibodies) that fight disease-causing organisms such as bacteria and viruses.
Antibody levels in colostrum can be 100 times higher than levels in regular cow’s milk.
Colostrum intake is critical for a newborn calf, as its immune system is not fully developed. The calf relies on colostrum from its mother until its own immune system is developed at one to two months of age.
Research has shown that the bacterial exposure of a calf at birth influences the amount of colostrum it will absorb. Early exposure of the intestine to large quantities of bacteria probably interferes with colostrum absorption.
If maternity stalls are used, they should be clean, dry and bedded well with dry grass.
Generally, a calf should receive 5 to 6% of its body weight as colostrum within the first six hours of life, and another 5 to 6 % of its body weight when the calf is 12 hours old. On day five, start feeding whole milk at a rate one litre/day for every 10kg live weight of calf. The ration is again split into two. Do not alter feeding times and quantity of milk.
Bottle-feeding can be used. Bucket feeding starts by inserting your two fingers in the bucket with milk and lowering the heard of the calf’s mouth into the bucket.
Roughage and concentrate
Gradually introduce good quality forage initially, from about two weeks of age. This stimulates rumen development and reduces problems of calf scours.
Introduce concentrate (calf starter) at about the same time pasture is introduced. Feeding is gradually increased, so that by 12 weeks of age, the calf is receiving 1-1.5kg per day. Any change over of feed type should allow a gradual adaptation to new feed at least over a period of seven days.
Sweet potato vine-based partial milk substitute Milk consumed by a calf constitutes 15-30% of the farm milk available for sale or processing in intensive (zero grazing) smallholder dairy cattle production systems in Uganda.
In order to minimise milk consumption by calves, farmers often resort to restricted milk feeding systems, thereby retarding calf growth, production and reproductive potential. Losses of up to 65% of daily body weight gains and 12% of body condition score have been reported. Under intensive dairy production systems, bull calves are often completely eliminated at birth, resulting in low productivity and consequent high loss of farm income.
Commercial milk substitutes provide the basic nutrient requirements that would otherwise be supplied by the cow’s milk, hence saving the latter for sale, processing and human consumption.
However, these commercial milk replacers are expensive and their use would be economically unjustified for most of the dairy farmers in Uganda, who are predominantly small-scale zero-grazers.
Most farmers, therefore, resort to restricted milk feeding and grazing as the only available option for raising calves, with bull calves most often culled at birth.
Never-the-less, dairy farmers still recognise that there is a considerable loss incurred when a cow delivers a bull calf and has to be culled at birth for economic reasons.
The sweet potato vine is one of the many feed resource that has attracted the interest of researchers as a potential feed resource for livestock.
Sweet potatoes (Ipomoea batatus) are widely grown and used for both food and feed. The protein content of the vines is about 18%, depending on the variety, age of plants, season, soil fertility and management of the field.
A partial milk substitute (PMS) ration-based on sweet potato vines and other locally available ingredients was developed by the National Livestock Resources Research Institute (NaLIRRI) under the National Agricultural Research Organisation (NARO). The ration comprises chopped, air-dried sweet potato vine meal (40%), maize bran (50%), fish meal (9%) and dairy mineral lick, (1%).
About 1kg per day of PMS is offered to the calf. Milk offered to the calf after day 14 is reduced by one litre fortnightly, until the calves are completely off milk at 10 weeks, allowing for gradual weaning and intake of PMS.
Advantages PMS ration
It reduces the amount of milk fed to each calf over the 70-day study period by about 120 litres.
Can be used as substitutes to reduce the cost of rearing a calf without adversely affecting its health and yet save more milk for consumption and processing.
A Friesian bull-calves can be raised with minimum resource input to add to the financial benefit of farmers under intensive dairy systems.
Weaning
The most common weaning age in intensive dairy systems is eight weeks. However, it may go up to 13 weeks, depending on the physical condition of the calf, body weight and feed consumption.
Calves should be weaned gradually when they are eating one or 2kg of calf starter per day. This practice not only reduces costs associated with the high price of liquid feeds, but also reduces the likelihood of calf scours.
Weaning may be delayed when the weather is cold or calves are weakened by previous or existing illnesses.
Housing a weaning calf
Calves should be housed individually until they are 9-10 weeks of age. High quality pasture may be offered in limited quantities after weaning.
Forage legumes such as Lablab purpureus (lablab) have high protein content, but legume hay or a mixture of legume-grass pasture cut before flowering is more palatable.
Continue to feed calf starter and limited quantities of pasture until starter intake reaches about 2kg per day. At this time, calves may be switched to a less expensive concentrate that will adequately supplement the forage fed.
The writer is a livestock nutrition expert
