Calf Rearing Front and Centre

When it comes to rearing calves, be it for replacement heifers or dairy beef, some basic nutritional guidelines make a notable contribution to overall success. They can be easily incoporated into any approach and will deliver good rewards.

Calf rearing counts among the farm disciplines that allow a degree of flexibility. Aspects such as feeding and weaning strategies are therefore often based on personal preference, or what works best alongside the many other roles and responsibilities on the farm.

Regardless of your regime, there’s one critical success factor to be aware of, namely “consistency of approach”.

You’re well advised to give your calves the same level of care, from the day they’re born until they’re weaned and in the paddock. The basics are good draught-free housing, clean water and quality feed (without signs of deterioration or a whiff of mustiness).

The focus on consistency is particularly important in matters of nutrition. The first and most important building block is good-quality colostrum. Its impact cannot be overstated; it delivers essential vitamins, minerals and immunoglobulins, all of which build immunity to disease and help to minimise health issues. SealesWinslow ruminant nutrition expert, Wendy Morgan, emphasises that colostrum should be fed as early as possible (ideally within the first six hours) and for at least four days, after which time you may move onto milk or calf milk replacer.

But liquid feed is only one part of the recipe!

As future ruminants, calves need to be introduced to solid feed very early on to ensure optimal development of their rumen. This is an important detail because the rumen (more specifically its papillae) determines how well nutrients can be absorbed.

Muesli and/or pellets, in addition to some hay or straw for roughage, are a great feed combination during the first few weeks in a calf’s life.

So, what should you look out for in feed composition?

First and foremost, look for nutrient-dense feed without so-called “fillers”. Wendy’s recommendation is to simply check the label or ask your rep. Aim for a high metabolisable energy level of 12.5 – 13 MJ/kg. What’s more, it should come only from quality ingredients. “Waste from lolly, chocolate or biscuit manufacturing can end up in calf feed because t’s cheap. But it doesn’t add any nutritional value beyond sugar and some starch. It also makes it difficult to achieve a consistent product, because the waste itself is quite variable. We therefore avoid it.”

Secondly, be careful to select a feed with the right protein content. Pellets with 20% crude protein, for instance, are specifically formulated for the needs of the very young calf, while the 16% equivalent is designed for older calves that are already getting some protein from pasture.

Once again, it pays to closely examine what’s on offer because, as Wendy explains, proteins aren’t created equal. “Ideally you want your feed to contain a high level of amino acids that help the calf grow lean tissue.” These amino acids come from quality plant ingredients such as soya bean, cottonseed, sunflower or canola.

Her final advice is to take a moment to evaluate the perception that feeding high levels of milk to calves is a cheaper option than buying pelleted feed. She recommends you “make sure that your decision is based on sound figures rather than assumptions or beliefs.” Even in the current below-average payout scenario, you might be surprised what you find when you do the sums. Chances are, you’ll keep the milk in the vat. 


Calf Housing

Calves require a dry, draught free environment with easy access to feed, fibre and fresh, clean water.

Calf housing needs to be clean, dry, with no draughts at calf level, and enough ventilation at a high level to prevent the build-up of ammonia and other gases.  Each calf needs about 1.5m2 of space and there should be 10 - 12 calves per pen at the most.

The main requirement of a calf shed is that it is twice as long as it is wide and/or high with no draughts.  This ensures calves have an area away from bad weather and prevailing winds.

Calf Housing

Calves need access to plenty of fresh, clean water, plus roughage in the form of hay or straw right from the beginning.  This will help to get rumen development of to a good start. To prevent the transmission of disease their food and water should be kept up off the floor of the pen. Having the pen ready before the first calf drops can help reduce stress.



The first 12 hours are a critical period in a calf's life, as their gut is best able to absorb the immunoglobulins in colostrum, which will give them immunity to disease.

The goal of a calf-feeding programme is to get stock to their weaning weights as rapidly as possible, while also supporting rapid development of the rumen.

The first step is to ensure calves obtain enough good-quality colostrum in the first 12 hours of their life. This is the period when their gut is best able to absorb immunoglobulins, the component of colostrum that will help to boost their resistance to disease. A calf with a strong immune system will have a lower risk of scouring, meaning better growth for the calf.

Regular pick-ups, preferable three times a day, are time consuming but worthwhile, as you can't depend on the cow supplying her calf with enough colostrum. Calves need to consume an adequate amount of colostrum,about 10% of their body weight, and it needs to be good quality (from the first milking).

Feed colostrum for the first four days, then move onto milk or calf milk replacer.


Choosing Calf Feed

The aim of all calf rearing programmes is to grow calves rapidly to target weights and develop them into productive milking cows. This is achieved through a combination of nutrition, management and health.

All calves need clean, fresh water from day one and should be offered good quality calf meal. With a multitude of calf meal options available making an informed choice is important, so what should you look for?

Great taste

Early feed intake is the key to good rumen development.  Premium calf feeds are formulated to high nutritional standards, however if calves don't like the taste, feed quality is irrelevant. Calf feed should smell fresh and taste great. To ensure calves continue eating, it is recommended staying with the same brand, making the transition from starter to post-weaning feed as smooth as possible.


High quality proteins are essential for calf growth, like: soya bean, cottonseed, sunflower and canola meals. These help build muscle tissue and are essential for many body processes. Low quality calf feeds may add urea to improve the protein percentage, however urea is not a 'true' protein as it does not provide amino acids which are building blocks for calf growth.


Calves only eat a small amount of meal, especially when young, so it is important to provide the best ingredients. Low quality calf feeds sometimes include 'fillers' such as palm kernel, bakery and confectionary waste, which are high in either fibre or sugar. Fibre is important for rumen development but should be provided in the form of clean hay or straw.

Vitamins and Minerals

Vitamins and minerals are essential for calves. Premium calf feeds are formulated by nutritionists to provide the ideal balance for calf health and development, e.g. calcium and phosphorus levels must be balanced to ensure good calf growth.  Other vitamins and minerals, particularly vitamin E and selenium, need to be included for immune function, to help fight off disease.


A coccidiostat, such as lasalocid (Bovatec) is essential to prevent coccidiosis, and must be included in calf feed at a rate to suit calf size. In order to ensure calves consume the required rates it is essential there is sufficient trough space for all calves to eat at the same time, otherwise some may gorge and therefore overdose, while others don't get to the trough, and under dose.


Rumen Development

Early rumen development is a vital part of the nutrition corner, ensuring the animal is weaned from liquid to solid feed as quickly and cost effectively as possible.

This then enables calves to utilise fibrous feeds and convert into meat or milk; an essential requirement of profitable production.

Rumen Papillae 

The papillae (finger-like protrusions) that line the digestive tract need to be developed to allow maximum absorption of nutrients that have been broken down from feed. The stimulus for this is production of volatile fatty acids (VFAs), in particular propionic and butyric acid. These are produced when starch containing materials, like, maize and barley, are fermented in the rumen. 

The breakdown of fibrous material does little to simulate papillae growth but is involved in improving the musculature of the rumen. It is physical fibre that does this, like hay and straw.

A high level of neutral detergent fibre (NDF) in calf pellets does not improve muscle tone. It can also mean less of the essential materials like grain and protein meals are included.  Calves eat a very small quantity of meal in the first few weeks. It is imperative that this feed is nutrient dense, containing the best quality ingredients available. 

Look at comparing price per unit of protein or per unit of ME to get a good view of what you are buying.  On a dollars per tonne basis, a feed might look very appealing but it is imperative to consider why this might be.  Cheap, filler raw materials are by-products and can be more likely to add to a mycotoxin risk. Young calves without a developed rumen struggle to deal with mycotoxins and can suffer from reduced feed intake, scours and a suppressed immune system.

Feed additives in calf meal play an important role.  This may be a coccidiostat, Rumensin or Bovatec. These additives reduce the level of coccidia that can affect the calf but do not totally eliminate them.  This allows the animal to recognise the challenge and as they get older, be able to fight it themselves. Other additives can be included such as prebiotics and probiotics.  Prebiotics are a “food” source for good bacteria in the gut.  Probiotics are good bacteria themselves. Using a calf feed containing a food source for good bacteria encourages their growth. The more good bacteria populating the gut, the less room there is for bad / pathogenic bacteria. In addition, the environment becomes less favourable for bad bacteria.  More good, and less bad, bacteria leads to a reduction in disease challenge, reduced incidence of scours and more nutrients available for growth instead of fighting a disease challenge.


Growth Targets

Whether you farm dairy or dry stock, raising strong, healthy calves is vital for the future of your business. Doing this successfully requires growth targets, regular monitoring and an appropriate feeding strategy.

In order to perform well, young stock need to reach their target weights on schedule. Beef cattle that get to their target weight on time can usually be sold for a better price than those that lag behind. Dairy cows that are raised well as heifers are more likely to have good reproductive performance than heifers that have been slow to develop. They are also more likely to reach their milk production potential.

Setting target weights is important. For male beef calves, the target should be based on your desired sell date: work back from there to determine checkpoint targets. Heifer calves that are going to be mated at 15 months should be 30% of their mature liveweight at weaning, and 60-65% at mating. Given that an LIC study conducted in 2012 found that 53% of heifers were more than 5% below their 6-month weight target, it’s clear that we have room for improvement.*

Once you have set target weights, you need to monitor stock progress. While it’s easy just to guess or go on age, it’s not very accurate. It’s worth investing in a set of scales and weighing calves on a regular basis to see if they are on track. The DairyNZ website contains targets for young stock at 3, 6, 9, 15 and 22 months.

A set of scales will also help to ensure you don’t wean calves when they are too light. Friesian calves on restricted milk and adlib meal can be weaned after they reach 63 kg; calves on a high-milk system need to be 75-80 kg at weaning.

To keep your calves on track, aim for steady growth; an adequate supply of suitable feed is an obvious essential, but keeping stress to a minimum is also important. One stressor that’s easily overlooked is, in fact, the feed. Abrupt changes to the feeding regime can cause growth checks, as calves take time to adapt to new feeds.

You can reduce the impact of new feeds by introducing them gradually, slowly reducing the proportion of the old feed and increasing the proportion of the new one. Minimise the number of changes at each step in the transition, e.g. if changing from muesli to pellets, choose pellets that smell and taste the same as the muesli. That way, the calves only have to get used to the new texture.

To make sure that calves wean successfully, focus on getting their rumens well developed. Feeding a quality calf starter containing 20% crude protein will help. Once they are on pasture, continue feeding them, gradually decreasing the meal allowance. Monitor stock growth to ensure they are meeting their targets and if weight gain is not on track, consider altering either the type of feed or the quantity allowed.

*McNaughton & Lopdell, 2012


Management and Set Up of Calves

Respiratory illness in calves is a common problem. These illnesses can be difficult to resolve, and they affect the long-term growth and productivity of calves. The best approach is to try to avoid respiratory disease arising in the first place; luckily, there are some management techniques that can help keep calves healthy.

One of the keys to minimising the risk of respiratory disease developing in calves is to ensure that their immune system develops as quickly as possible. A calf with a well-developed immune system will be better able to fight off unwanted viruses and bacteria by producing antibodies to these organisms.

When calves are very young, their immune system is not able to produce antibodies effectively; instead, these calves rely on antibodies supplied in colostrum. Providing calves with sufficient good-quality colostrum in the first hours after birth will help to ensure they are capable of fighting off disease. Ideally, calves should take 10% of their body weight in colostrum within the first 12 hours.

The living conditions of calves also influence their susceptibility to disease. Damp conditions in the shed provide an ideal habitat for fungi, viruses and bacteria to flourish. These can be transmitted on dust particles. If one calf becomes infected, it will not take long for the disease to spread, and the rate of spread will be more rapid if calves are crowded into pens. To reduce the effects of overcrowding, allow 1.5 m2 per calf, and have no more than 10-12 calves per pen. A pen with solid sides can also help to reduce the transmission of disease. A dry, well-insulated surface, such as wood shavings or straw, will also increase stock comfort and boost their health.

The air around the calves also needs to be considered. Calves need draught-free conditions, but the area must also be well-ventilated to prevent the build-up of harmful gases such as ammonia. Ammonia arises from the breakdown of urine in the bedding, and if it’s allowed to build up, it will irritate the calves’ respiratory system, predisposing it to infection. Aim to have the area around the calves free from draughts, but the area above them well ventilated, to allow gases and dust to escape. If you can smell ammonia in the shed, then it’s likely that the ventilation is not adequate.

Calves also need good nutrition – provide plenty of fresh, clean water, plus roughage in the form of hay or straw. To prevent the transmission of disease, keep the food and water up off the floor of the pen. Make sure there is sufficient feed for each animal in the pen – if they have insufficient feed they will become physically stressed and more vulnerable to disease. Having to compete for feed will also increase the animal’s stress.

Other stressors that can reduce a calf’s resistance to disease include transportation, changes to their feed, dehorning, castration and mixing groups of animals. All of these should be managed to minimise the amount of stress they cause.

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