The first three months of a calf’s life are critical. The growth rate achieved in this period will affect the lifetime performance of the animal. Optimising nutrition and minimising morbidity is essential to ensure the calf has the best possible chance of achieving its full genetic potential for growth and feed conversion efficiency.
Calf-rearing systems need to recognise that early life events have long term effects on the performance of the calf and capitalise on them.
Set targets for your calf rearing enterprise
Buying or rearing calves, whether to sell on again or as part of your beef enterprise leaves tight margins. Objectives must be set for the enterprise and protocols should be designed to ensure the objectives are achieved.
The critical targets for rearing dairy beef calves up to 15 weeks of age are as follows:
Minimal mortality:
Target per cent per cent mortality with a maximum of five per cent.
Minimal morbidity:
If the calf suffers setbacks from poor health, feed intake and average daily gain will be affected. Low morbidity will also minimise treatment and medication costs per calf.
Optimal daily liveweight gain:
Calves should average 700 – 800 grams / day up to 15 weeks
|
Age (weeks) |
Target live weight (kg) |
||
|
AA/Hereford |
Holstein |
Continental |
|
|
1 week (purchase) |
45 |
48 |
50 |
|
6 weeks (weaning) |
70 |
73 |
75 |
|
12 weeks |
100 |
102 |
105 |
|
15 weeks |
117 |
119 |
122 |
Source of the calf
Most beef enterprises depend on the calf being purchased rather than the calf being born on the farm. If possible calves should be purchased where background information including disease status, colostrum supply, and feeding regime prior to purchase are available. This information will be beneficial to help ensure calves are of optimum health at the time of purchase. Calves should preferably be purchased from farms which have control programmes in place against economically important diseases such as calf scours, BVD, and IBR.
Purchased calves should be inspected thoroughly, and calves that are dull or listless, show signs of diarrhoea or have discharges from the eyes, nose or mouth should be rejected. Calves should be lively, have a shining coat, bright eyes and a clean moist nose. Consistent batches of calves purchased from the one source is the ideal as mixing calves from various sources
Calves should not be moved from the farm of origin until at least seven days of age and preferably not until they are three to four weeks of age as this will reduce the high risk of scours and stress in the young calf aged less than three weeks.
Purchased calves should be isolated from resident calves for one week to allow them to be monitored for any disease problems and ensure they do not carry or spread infection to the remainder of the herd.
Calves being purchased which have not had the absolute minimum amount of good quality colostrum (three litres within two hours of birth from the first milking) are going to be potential disease risks on farm. Good quality colostrum not only helps to protect the young calf against disease but it also has a major effect on the development of the intestinal tract leading to improved intake, growth and long term performance.
A good relationship between the purchaser and provider will be beneficial, since knowledge of the source, disease status and colostrum status of purchased calves is vital.
Feeding the calf
Due to cost, availability and ease of management, milk replacer will be the choice of the majority of calf rearers, focused on beef from the dairy herd. The quality and quantity of proteins in the powder is vital – it should have a minimum of 20 per cent protein and preferably 23 per cent to support good frame growth. Protein concentration below 20 per cent will reduce live weight gain and will impact on the compaction of weight gain. Protein quality can be an issue, particularly in the first month of life so it is important that the milk replacer used has sufficient (contains mainly) milk derived proteins during this period.
Fat levels should be 18- 20 per cent with sufficient minerals and vitamins. Fat levels of 18 – 20 per cent will encourage early intake of concentrate ration.
Traditionally, economics drove the feeding rates with a target of 1.25 / 1.5 bags of calf milk replacer targeting 6 – 8 weeks old at weaning. Research now shows that achieving the targeted gain of 700/800 Grams and 120 kgs at 15 weeks is the key. The total amount of milk solids fed / day, as opposed to the milk volume is the key. To achieve 700/800 grams / day of growth, the calf will need to consume 650 to 700 grams of good quality milk powder / day. The amount to feed will however depend on the number of days on farm, calf entry weight, dry feed intake, and the target growth rate and exit weight.
Feeding systems
Provided calf health, husbandry and housing are correct calves can be successfully fed using a variety of systems, including cold ad libitum, warm ad libitum, bucket fed once or twice a day and computerised feeding systems.
The system used must be suitable for the labour and housing available, and irrespective of the feeding system, it is important to ensure that the energy and protein content supplied/calf/day is enough to support the target growth rate. Calves need to be fed twice a day with milk for at least the first four weeks of life to satisfy their nutritional needs. But by four weeks of age, the calf starts to eat increasing amounts of solid food, and will be able to start digesting it.
If the calf is consuming adequate dry feed at four weeks of age, the amount of milk offered can be reduced to encourage solid feed intake. Feeding twice a day for at least the first four weeks of life also allows the rearer to check drinking speed, volumes consumed and general demeanour of the calves.
With increasing numbers and batches of calves being put through systems, computerised calf feeding has gained in popularity. Computerised feeders cut down labour significantly and allow time for improved calf husbandry. The little and often feeding promotes calf health and encourages earlier intake of dry feed. Probably the biggest advantage of computerised calf feeding is the gradual weaning where setbacks to growth rates are avoided.
Irrespective of the system, consistency in milk temperature, concentration, volume and time of feeding is key.
Water, roughage and dry feed
In order to achieve a targeted 700 to 800 grams / day the calf must start eating a high quality calf starter as early as possible in life. This should be offered from the first week of age. A good quality calf starter should typically contain 12 M.J. energy, 18 – 20 per cent crude protein and at least 25 per cent Starch Sugar with enough fibre to avoid digestive upsets. Calf starter should be palatable and dust free, and refreshed daily to encourage early intake. For roughage supply up to weaning, clean fresh barley or oaten straw is preferred.
In addition to milk, clean fresh water must be available at all times from day three, to support rumen development. Water contained in the milk is not enough because milk bypasses the rumen in healthy calves. Water is also important to encourage dry feed intake – for each 1 kg of concentrate consumed the calf will drink 4/5 litres of water.
Calf diseases
As with all diseases, prevention is much more efficient than treatment. Ensure a good bio- security and farm health plan is in place which is monitored by your veterinary surgeon. As discussed above, bio-security issues such as knowing the disease status of the source herd, using and checking colostrum status, rejection of sick calves, buying a three week old animal, isolation of new animals on farm all improve the chances of minimising disease.
Well bedded and well ventilated housing with a good protocol around hygiene and calf husbandry will also help to minimise disease risk.
Weaning calves
The criteria for successfully weaning calves are:
- Consuming at least 1kg calf starter / day for three consecutive days
- Body weight of 80 to 85 kg
- Minimum age of eight weeks
- Healthy and not stressed
Calves can be weaned either abruptly or step weaned (stepping down the amount of milk fed and the number of feeds / day). There is no major difference between step weaning and abrupt weaning, providing the calf’s rumen is adequately developed and that they are eating at least one kg of calf ration / day. However, gradual weaning does reduce the stress at weaning and can avoid temporary setbacks in growth rate performance.
Weighing calves on at least two time points during the rearing period is an excellent way to check their health and performance, thus highlighting if any nutritional changes need to be made.
If possible weigh calves at birth, or at the time of entry onto the farm, and again at 6-10 weeks. Alternatively weigh calves at time points that coincide with existing management practices (such as dehorning) to minimise additional labour requirements.
Weigh scales offer the most accurate measure of calf weight and, if set up correctly in a race or crush, will be the easiest method to use. If weigh scales are not available, use a weigh band (girth tape) or height stick or height marks on the crush wall. Using the same measure and being consistent is key.
Successful calf rearing with minimum mortality, low disease levels and efficient use of labour and other inputs is critical for profitable dairy beef production. It is a costly enterprise and high standards need to be set and met. It is extremely important to set objectives for your calf rearing enterprise and to monitor these objectives with every batch of calves reared. Excellent husbandry together with the correct nutrition will help ensure calves achieve their full potential, resulting in an efficient and profitable enterprise.
By Maggie Gould and Jessica Cooke, Volac International Ltd.Orwell, Hertfordshire United Kingdom. Both were speaking at today’s Teagasc National Beef Conference in Kilkenny.
Pictured calves on outdoor pad. Photo O’Gorman Photography
