Three different dairy cattle feeding systems are discernible in the country:
1) The extensive system where cows are totally grazed, and only supplemented with concentrates, usually at milking time. This system is applicable where the dairy farmer can afford to allocate two to four acres of grazing land per cow.
2) The semi-intensive system where grazing is inadequate, and supplemental forages are brought in from elsewhere.
3) The intensive system where cows are totally confined and feeds are brought to them. This system is applicable where land is limiting.
Each cow has to produce at least 20 litres of milk per day for this system to be profitable.
The principles discussed in this article apply to all management systems. Nutritional needs of the dairy animal are critical in the productivity of the herd.
Feeding costs can be as high as 70 per cent of the total cost of production. Profitability in a dairy farming business thus hinges on how well you manage the feeds. Some of the targets that you can work on are:
• Weaning the calf at three months or less to reduce the milk feeding costs.
First insemination of the heifer at 15 months or less so that the first calving time is at 24 months or less.Lifetimee profitability from a cow is reduced if first calving goes beyond the age of 26 months.
• The average milk production of at least 20kg per cow per day.
Cattle are fed for maintenance of body weight and for production. If maintenance requirements are not met, the animal will use its body weight to maintain the essential metabolic functions, thus losing weight or milk output. Production is in terms of weight gain or milk yields.
A growing animal should steadily gain at least 500 to 800g per day for you to hit the weaning and insemination targets.
A calf that loses weight will require more time to compensate for the losses. At today’s input costs and milk prices, anyone who wants to do dairy farming as a business should aim at a minimum production level of 20kg of milk per cow, per day.
This can only be achieved if the cows are well-fed from birth through lactation. Underfed cows will cut down on milk production, using the little nutrients available for maintenance. Here are some suggestions on how best to hit growth and production targets.
Feeding the calf
Calves are fed milk according to their body weight. It is, therefore, necessary to get the weight of the calf at birth then every two weeks thereafter.
Accurate weights are usually obtained from fasting animals, so weigh the calf before feeding it in the morning. Heart girth measurements provide good weight estimates.
Place a tape just behind the front legs of the calf, record the girth in centimetres and convert to weight using standard conversion tables. However, weigh bands are available on the market from which you can read the animal’s weight directly.
Early in life, the calf is rapidly laying down muscle on very fast-growing bones. Thus, calves require a good supply of minerals and protein for growth and development. These nutrients can be supplied from milk fed at the rate of 10 per cent of their body weight per day.
Along with the milk, provide an ad libitum (that is, available all day) supply of a commercial calf supplement, good quality chopped fodder such as the protein rich sweet potato vines, and a supply of cool clean drinking water.
It is a myth to say that calves that drink water pass bloody urine. Bloody urine is an indicator of a disease, which can be treated.
You know it is time to start weaning your calf from milk when:
1) The calf weighs over 70kg.
2) It consumes over 1kg of the commercial calf supplement.
3) It is at least eight weeks old.
When you observe any two of the above three conditions, start reducing milk gradually to zero over the next four weeks.
As you reduce the milk, the calf will be encouraged to eat more solid food, so reducing the weaning shock. After weaning the calf from milk, continue providing the green fodder or good quality pasture where available.
Weaned heifer calves should be grazed on nutritious pastures sufficient to meet their maintenance and growth requirements.
Use the same pre-weaned commercial concentrate formulated for calves at the rate of —–2kg per day (depending on the quality of pasture or green fodder) to supplement the grazing by heifer calves from three to six months of age.
Feeding the heifer
At the age of six months, switch to a cheaper young stock supplement (at the rate of 1 to 2kg per day depending on the condition of the animal and the quality of pasture or fodder) up to the age of 12 months.
Water and an appropriate mineral supplement usually referred to as a ‘stock lick’ should be available all day. If you are resource-constrained, then, instead of the young stock supplement, simply use 1kg crushed grain per heifer, per day, but you will miss the first insemination target.
Also, if you have good quality pasture or fodder, you can do without supplementing your heifers above six months and achieve reasonable growth.
Watch the body condition of the heifers from 12 months on. Overfeeding can result in over-fat heifers with reduced conception rates.
At this stage, Rhodes grass or Nandi setaria mixed with desmodium, supplemented with sweet potato vines or leguminous fodder shrubs, form good feeds and reduce feeding costs. Provide the heifers with unrestricted amounts of minerals and clean water.
If you do everything right, the heifer will start bulling (behaving like a bull) at nine months and show first signs of heat at 11 to 12 months.
Inseminate the heifer when it is three quarters the average adult weight for its breed. For example, for breeds that average 400kg adult cow weight, first insemination can be when they weigh 300kg.
It might, therefore, be necessary to delay first service to second or third heat for underfed, slow growing heifers.
Feeding the in-calf heifer
Conception after insemination depends on the how well the heifer is fed. Underfed heifers are likely not to show any signs of heat, and may fail to conceive at first service.
Heifers that conceive can be maintained on pasture or cut fodder with the young stock supplement at 1 to 2kg per day and an adequate mineral supplementation to cater for the growth of the heifer herself and the calf she is carrying. In the 3rd trimester of pregnancy, the supplement for heifers can be changed to dairy meal.
Steaming up of in-calf heifers and cows
Steaming up is the practice of feeding high amounts of dairy meal to the cows and heifers before calving. This is done during the last six and eight weeks before calving respectively for cows and heifers. The purpose of steaming up is to:
•Provide nutrients to meet the demands of pregnancy. The highest rate of development of the calf, embryonic and mammary tissue take place in the last trimester of pregnancy, hence nutrient requirements by the cows and heifers are high at this time.
•Ensure a healthy calf at birth that is more resistant to diseases and grows faster.
•Provide more nutrients to meet the heavy demand of the coming lactation.
• Stimulate the development of the udder in heifers and replenishing (refurbishing) of the udder in cows.
In the last six weeks of pregnancy, in-calf heifers and cows are given a gradually increasing rate of dairy meal supplementation so that by the time of calving, they are consuming 3 to 6kg dairy meal per day. This will ensure proper udder and calf development.
The following table shows the steaming up schedule for cows and heifers. Feeding is done twice a day.
At calving, the cow will be consuming 6kg of dairy meal a day. From then on cows are fed according to production.
Feeding the lactating heifer or cow
Lactating cows are fed good quality fodder/forage, and dairy meal at the rate of 1kg dairy meal for every 1.5kg milk produced above 5kg.
If the quality of forage is poor, you will need to give more dairy meal, but do not exceed 40 per cent of the total feed intake per day. This of course will raise your cost of milk production, eating into your profits.
Challenge feeding: This will enable you to know the milk production potential of the cow. Give the cow a bit more dairy meal than she requires to produce milk. If production increases, increase the amount of dairy meal again. Repeat until the milk stabilises. From then on, feed according to production as indicated above.
Pastures and fodders are the cheapest feeds available on a dairy farm. Therefore, emphasis should be placed on the utilisation of these feeds to raise high milk producing dairy cows.
Dr Lusweti is an animal nutritionist and a senior principal research officer, Kalro, Kitale