FIRST 12 WEEKS CRUCIAL FOR TWO YEAR CALVING

Dairy farmers targeting two year calving should pay close attention to the first 12 weeks of the calf’s life according to NWF National Calf Specialist Leigh Berrisford.

“The first few weeks of a calf’s life have an enormous bearing on subsequent growth as a heifer, and farmers looking to calve heifers down at the optimum age of two years can not afford to let calves fall behind the target growth rate,” comments Mr Berrisford.

“If the aim is to maximise the lifetime profit of the cow, then the rearing costs of the first 12 weeks should be seen as a vital investment for the future.”

NWF recommend that calves should weigh 100kg by 12 weeks of age and that this growth is achieved consistently over this period. At four weeks they recommend a target weight of 56kg while at eight weeks old the calf should be weighing 76kg.

“These growth rates are perfectly feasible provided the calf is kept clear of disease and is fed a consistent high quality diet. Sudden changes in diet will test their ability to cope and may predispose them to scours. Simple factors such as over-feeding or changing to a lower specification milk replacer can adversely affect digestion and a calf’s willingness to drink.”

After adequate colostrum has been fed Mr Berrisford advises the calf should receive a good quality milk replacer for the next eight weeks. Concentrates should be made available from day four and calves should be consuming 1kg per day before weaning.

Hay or good quality straw should be available to develop good rumen capacity and to encourage the development of the rumen villi. This will promote higher feed intakes after weaning.

“The development of the digestive tract is one of the crucial physiological changes that occurs during the first few weeks and is one of the reasons why it is important to observe high standards of hygiene around young calves.

“The agents that cause infectious scours such as E.coli, rotavirus, coronavirus and BVD all attack and degrade the intestinal lining leading to reduced feed absorption and lower growth rates.”

Mr Berrisford believes farmers should be prepared to measure growth regularly in young calves, arguing this is the only way to check if they are growing at the desired rate. He also maintains that regular recording will show when animals fall behind the target growth rate allowing action to be taken.

 “For example, it is not unusual for calves to suffer a growth check around weaning and this will show up if weights are being recorded. It might be necessary to delay weaning until concentrate intakes are adequate or to adopt a policy of phasing weaning over a few days. It is hard to tell just by looking at calves whether they are growing fast enough.”

Growth rates can be simply assessed using a calibrated weigh band which is used to measure the chest girth just behind the front legs and Mr Berrisford advises measuring a few calves in every batch on a regular basis.

 “The investment in the time to weigh band calves is a small price to pay if it means calves grow quickly and are able to calve down at two years old. In this way the animal will have the best chance of delivering a high lifetime profit,” Mr Berrisford concludes.