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Successful calf rearing: from birth to weaning

Successful calf rearing: from birth to weaning

Successful calf rearing: from birth to weaning

Raising healthy dairy calves is a key component to achieving future high production and to increasing the lifetime performance of the dairy’s cows and bulls. A successful heifer rearing programme would be to have a healthy calf, achieving optimum growth rates and a successful weaning, while also hitting performance targets. This will enable her to calve down into the herd at 22–24 months, giving her the best opportunity to reach her future lifetime milk production.

Four key areas must be considered when aiming to rear healthy calves and keep mortality to a minimum:

  • Colostrum

  • Early nutrition

  • Environment

  • Rumen development and immunity


  1. Colostrum

High-quality colostrum given at the right time is the foundation of success for any calf rearing enterprise. Colostrum is vital to the newborn calf because it contains antibodies (also known as immunoglobulins, or IgG), which provide immunity. It is also rich in energy and nutrients that are essential for growth. Newborn calves must receive at least three litres of high-quality colostrum within the first two hours of birth from the first milking. The only exception to this is Holstein calves, which require four litres. A second feed should then be given eight hours later, before transitioning to milk or calf milk replacer.

A calf is born with no active immune system to protect against disease and depends solely on passive immunity from colostrum feeding. After the first few hours of birth, the calf’s ability to absorb essential antibodies from colostrum reduces significantly as the gut barrier loses permeability. Quality of colostrum also needs to be considered; high-quality colostrum contains at least 50 g/L IgG. The IgG concentration of colostrum can be measured with a refractometer or a colostrometer — these are freely available and inexpensive.


  1. Early nutrition

There is no single system of calf rearing suitable for all dairy farms, and many systems can be successful. However, there are basic nutritional requirements that should be met, regardless of the feeding regime.

During the first few months, a calf is most efficient at turning feed into weight gain. Current recommendations for feeding dairy calves are to offer 15% of the body weight in whole milk or milk replacer mixed at 125 g/L water. The abomasum of a newborn is not large enough to deal with six litres of milk in one feed, so the feed should be split until they are at least three weeks of age. Remember: as calves grow, they will require more energy, so volume and energy must be increased.

Calves need 325 grams of milk solids for maintenance alone. Milk is 12.5% dry matter, which equates to 2.6 litres. If a 40-kg calf is fed four litres, they can only gain 200 grams per day, meaning taking a long time to achieve the target weaning weight or weaning at a low weight.

Water is a vital part of calf nutrition and one that is often disregarded if they are on milk. Clean, fresh water should be readily available from week one. The development of calf starter intake depends on water intake. It is important to remember that milk goes into the abomasum, bypassing the rumen. Hence, there is no water/moisture to aid the digestion of the calf concentrate in the rumen.


  1. Environment

Suitable calf housing is also a crucial factor in rearing healthy calves. Calves spend 80% of their time lying down and need a dry, draught-free bed; adequate water access; light and sufficient fresh air to breathe. Straw bedding should always be at least 15 cm deep and remain dry to provide warmth and comfort. With a shortage of straw this year, alternative bedding may need to be considered, such as wood chip or peat. These may need to be topped up regularly to ensure they stay consistently dry. Calves lying on a cold and wet bed use energy for warmth rather than growth. Calves in groups will need at least 1.1 square metres of lying space up to eight-weeks old, and 1.5 square metres after that. It is essential to avoid changes within groups and to group calves according to size and age.

The shed should be thoroughly cleaned and disinfected with a broad-spectrum disinfectant before calves arrive. While in use, pens should also be frequently disinfected to prevent the build-up of disease organisms. Hygiene around milk feeding is also vital: cleaning all feeding equipment is necessary for maintaining healthy animals, and prioritising younger animals first, along with rinsing before feeding the other batches, will help mitigate the spread of disease.


  1. Rumen development and immunity

Calf rearing will take up a large proportion of the morning and evening routine on most farms. It can be time-consuming at the best of times but can be particularly frustrating if calves’ immunity is compromised.

Developing a healthy rumen is one of the first steps to a healthy animal, establishing a robust immunity that will lighten the workload for everyone involved. Giving the calf the best opportunity to develop and gain weight means ensuring a healthy rumen and working gut function. At 10 weeks of age, a calf should be double its birth weight at weaning. An average daily gain of 0.6kg LW/day should be the target all calves are looking to achieve this spring. A developed rumen supports greater efficiency in breaking down feed, leading to an improved weight gain over the calf’s life.

At InTouch, we do not advise feeding hay or silages to pre-weaned calves. This can slow growth and negatively affect starter intakes. Calves are unable to digest large quantities of forages and consumption of this material can lead to ‘pot belly’ calves, which increases rumen fill, leading to reduced starter intake and overall poor performance. The use of 8–10% of chopped straw as part of the calf concentrate can encourage rumen strength, as well as allowing the concentrate to be fed safely between weaning and grass, or any other changes in diet. The starch in the concentrate will help to drive papillae development. It is also important to make sure any concentrate is highly palatable and dust-free to avoid respiratory issues.

Scour is responsible for nearly 30% of calf deaths, while also resulting in poor growth and performance and a lot of work for the farmer. Prevention is better than cure, and a lot can be done to help prevent diarrhoea problems on a dairy farm. Including Actigen® in the diet will benefit all calves by modifying and improving the intestinal microflora composition. They have been proven to help manage the risk of diarrhoea in calves and improve feed conversion efficiency, as well as increase starter intake and weight gain.

Actigen can provide calves with the best possible start to building up a strong immune system. It can be used to reduce scour in calves and, as it is a yeast-based product, lead to improved feed efficiency. Actigen can be included in the milk replacer or calf ration at an average inclusion rate of 1.5 g/day.

For more information or to speak with a nutritionist contact InTouch on +353 (0)59 9101320.