Making most of heifer growth rates

Feed conversion efficiency (FCE) is optimum in young animals – that’s a fact.

Heifer replacement FCE is highest in the first eight weeks of life after which it rapidly tails off – check out the graph.

In the first two weeks, 100g of feed will give approximately 50 – 60g of growth, after which it dramatically falls during the first 12 months of life, by when 100g feed will only give approximately 9g of growth.

Heifer feed efficiency

Feed conversion efficiency table

 Source: IRTA

* (Average daily gain) / (dry matter intake) x100

Feeding for growth has also proved to be cost effective according to research findings from the Institute of Research and Technology in Agrifood (IRTA). To achieve average age at first calving at 23 months and a body weight of 650kg, feeding a total six litres of milk per day to weaning at two months resulted in the lowest total rearing feed costs.

The data in the following table confirms that heifers fed four litres during the same period had some catching up to do later on when FCE is lower. In other words it is cheaper to put weight on heifers earlier.

Milk volume fed and the impact on total heifer rearing costs
(calving 23 months, 650kg body weight)

Volume milk fed (l/day) during first two months Average weight gain during first two months (kg/day) Total rearing feed cost (£)
4 0.5 759
6 0.8 729
8 1.0 738

 Source: IRTA

Three reasons why FCE is the highest in early life

  1. Milk is more digestible and nutritious than concentrate to a young calf.
  2. Calves fed concentrate utilise the ME that they consume less efficiently than the energy derived from milk or calf milk replacer. This is because at least some of the carbohydrate and protein in starter feed must be fermented in the rumen prior to being digested by the calf. As rumen activity increases, the amount of heat produced by the animal also increases which can be considered a loss as it cannot be utilised by the animal.
  3. Before puberty, growth is mainly bone and muscle, after which heifers gain more fat relative to bone and muscle, consequently they are less feed efficient.

New born calves – meeting their nutrient requirements

Are you facing the dilemma of feeding whole milk or milk replacer?

Whichever you decide, remember the calf’s physiology dictates that for the first three weeks of life, she will be almost entirely dependent on liquid milk feed to supply the nutrients she needs to support health and growth.
Let’s take a look at pros and cons of each…

Whole milk

The pros:

  • contains a high level of energy – 30% to 32% fat which is highly digestible
  • provides a high level of protein (amino acids), 26% – 27% protein

The cons:

  • can transmit bacteria which infect the calf, including Johne’s, Salmonella, E.Coli
  • can vary in nature which can lead to calf performance / health issues
  • can result in delayed intake of solid feed, which can delay the age of successful weaning or result in post-weaning growth checks


High quality calf milk replacers

The pros:

  • the proportion of energy supplied by the fat and lactose combined is similar to whole milk, despite the fact replacers contain 16% to 20% fat
  • contain a blend of fat sources which are designed to be well digested
  • lower fat, higher lactose – stimulates earlier intake of solid feed which encourages earlier rumen development both before and after weaning
  • formulated to provide a consistent supply of energy, protein, vitamins and trace elements to meet requirements
  • biosecurity – made using pasteurised milk
  • convenient and easy to use, and always available


The cons:

  • have to be purchased

Calves have a requirement for protein, a minimum of 20% in the diet, but they also require specific amino acids – the building blocks of protein. The total quantity and balance of amino acids, not crude protein %, is key to muscle development and calf growth, but only the protein % is declared on the product label so it is impossible to judge likely animal performance from reading the label alone.

Five ‘must haves’ when purchasing a milk replacer

  • Minimum of 20% protein declared
  • Maximum of 9% ash declared
  • Minimum 0.8% calcium
  • A trusted supplier
  • Previous calf performance and calf bloom give the best guarantee for the milk replacer’s quality

RABDF Youngstock Walk 2015 – realise your full potential



Find out how to improve your young stock rearing at this focused farm walk hosted by Phil and Jane Ashton at Peters Marland, Torrington on Tuesday 22nd September.

Organised by the Royal Association of British Dairy Farmers (RABDF) and sponsored by Boehringer Engelheim, For Farmers, Volac and XLVets, the events will focus on calf diet management, health, welfare and housing.

Speakers at the farm walk will include representatives from the sponsors and farm buildings specialist, Jamie Robertson who will discuss managing air climate – keeping cold calves cosy but fresh.

There will also be an opportunity to tour the Ashton’s calf units. The couple manage a 180-cow autumn block calving Jersey herd. Calves are reared in igloos and heifers are weighed at frequent intervals from birth to ensure they are on target to reach 250kg to 280kg for service in order to calve at 23 to 24 months.

Programme of events
10:30am – Registration and refreshments
11:00am – Welcome by RABDF
11:10am – Farm introduction by the host farmer
11:20am – Farm walk commences (please bring suitable clean footwear). The following key areas will be covered:

  • ‘Prevent profit going down the drain – dealing with calf scours’ – Boehringer Ingelheim Ltd
  • ‘Feeding the Future’ – For Farmers
  • ‘Feed for Growth: Growing better cows’- Volac
  • ‘Make your Farm a Fortress – Johnes & BVD Control’ – XL Vets
  • ‘Managing calf climate; keeping cold calves clean, cosy but fresh’ – Jamie Robertson

1:20pm – Lunch and opportunity to speak to farm suppliers and event sponsors

To register visit or call 0845 458 2711

RABDF logo

Calf rearing system tweaks help increase growth rates

calf_somerset Tweaking your calf rearing system can help to increase growth rates – that’s a fact.  It’s a case of siting down, working the routine and then considering at each step, ‘how could we possibly do things better’.

We’ve talked to two producers who have made changes and are already seeing the benefits of feeding for growth.

Marie Walkden, herd manager, Village Farm, Emmington, Oxon
210 Holstein cows, ave 9,000 litres
Age at first calving 26 months, target 24 months


  • We were target feeding colostrum within the first six to eight hours
  • We used to feed waste whole milk twice daily to weaning


Revised system

  • We feed a minimum 2.5 litres of colostrum within the first two to three hours
  • We’ve swapped whole milk for milk replacer; we feed twice daily a total of five litres mixed at 160g/litre
  • We ensure consistency – each day the milk replacer powder is weighed on a digital scale and milk temperature is taken with a digital thermometer to ensure we are feeding it at 40°C

The results

  • Scouring has reduced to a minimal number of incidences
  • Growth rates have increased to 0.83kg/day and we are confident we are moving in the right direction for the heifers to reach target weight for first service at 14 months

Mark Thornton, farm manager, The Parkes, Audlem, Cheshire
300 Holstein Friesian cows, ave 9,500 litres
Age at first calving 29 months, target 24 months


  • We fed colostrum for the first three days and moved on to milk replacer
  • Calves were housed in individual pens with buckets for the first two or three weeks, after which we introduced them to groups of 10 and started trough feeding
  • Within a group of 10, the age difference could vary up to one month, and the smaller calves were getting pushed out of the trough

Revised system

  • We’ve moved from bucket and trough to feedercomputerised feeding system
  • Each calf is going in to a stall to feed, so it isn’t vulnerable to being pushed about
  • She receives a regulated amount of milk each day delivered at a consistent temperature, and she is drinking the amount she wants, when she wants it

The results

  • Growth rates have progressed to an average 0.75-0.8kg/day
  • Scouring has reduced
  • The heifers are getting a much better start and our first batch on the new system should reach around the 24 month target age at first calving

Colostrum, the key to success – part 2

The dam: does colostrum quality vary between cows?
Yes, it does, and there are several influences.

1. Age – colostrum from heifers usually contains fewer antibodies as these animals have yet to be exposed to a wide range of bugs. However, feeding regimes and vaccination programmes can result in heifers producing good quality colostrum. Never discard colostrum from heifers without testing it with a Colostrometer first.

2. Breed – Holstein colostrum contains lower antibody levels than Jersey colostrum.

3. Dry periods of less than three weeks reduce antibody levels.

4. Higher yielding animals – genetic selection for high milk production is resulting in cows producing higher volumes of colostrum with a diluted level of protective antibodies. The volume of colostrum can range from 2.8 to 26.5 litres in Holsteins. As a rule of thumb, if a cow produces above eight litres of colostrum it is considered to be at risk of being too dilute.

5. Dry cow vaccination programmes and disease history are influential. Animals must be exposed, or vaccinated against, a disease to produce the specific antibodies that will destroy the disease causing organisms.

6. Dry cow nutrition – inadequate protein, energy and or vitamins during this period will lower colostrum quality.

7. Hygiene – high levels of bacteria in colostrum can reduce the calf’s antibody uptake. Ensure that cows calve into clean dry pens, udders are clean, milking and calf-feeding equipment are kept clean, and colostrum is stored in clean containers to minimise the calf’s exposure to bacteria.

8. Collection timing – antibody levels decline rapidly post calving. Milk the dam as soon as possible.

9. Processing – heating or thawing colostrum in a microwave or with very hot water can reduce the effectiveness the valuable antibodies. Use a water bath with a temperature no higher than 45°C to gently defrost and heat colostrum.


When should colostrum be collected?
As soon as possible after calving. Colostrum collected two hours after calving has the highest content of antibodies, after which the level rapidly falls.

Source: Moore et al., 2005

Handling and hygiene
High levels of bacteria in colostrum can reduce the calf’s antibody uptake. Therefore minimise the calf’s exposure to bacteria by making sure that

  • cows calve into clean dry pens
  • udders are clean
  • milking and calf-feeding equipment are kept clean
  • colostrum is stored in clean containers


How should good quality colostrum be stored?
If you have surplus good quality colostrum then always store to ensure you have a supply at all times.

  • In the freezer at -20°C for up to one year in small quantities, for example 1.5 litres.
    Zip-lock freezer or foil lined bags are ideal.
  • In the fridge at 1-2°C for up to seven days in small clean containers.

Routinely check temperatures of either fridge – ideally 1-2°C, or freezer – ideally -20°C.

Label all storage containers with the cow ID and date. If Johne’s is later identified, then you’ll be able to check the history of which colostrum was fed.

Colostrum is a perfect medium for bacterial growth, therefore feed, chill or freeze ideally within two hours of collection. If left at room temperature, then the bacteria present will double every 20 to 30 minutes.

Should cow colostrum or colostrum alternative be fed?
Cow colostrum is always best since it will contain antibodies that are specific to the bugs and diseases on your farm. Ideally, use colostrum from the calf’s dam.

Colostrum alternatives are available, however use only as a backup option. They will never provide the same protection levels as good quality colostrum from cows on your farm.

Colostrum, the key to success

What is colostrum?

Colostrum or first mother’s milk is secreted in the udder immediately after birth. It is rich in vitamins, trace elements, minerals, energy, protein and antibodies.

Why is colostrum important? Two major reasons:

1. A new-born calf is born with no immunity; it has no protective antibodies to fight off disease. Colostrum is a rich source of these antibodies which identify and destroy disease-causing organsims in the calf. That’s why colostrum is absolutely vital to help protect a young calf against diseases in its first few weeks, until its own immune system starts to function.

2. Colostrum provides the first source of nutrients after birth. If a calf doesn’t receive sufficient colostrum then you can expect low growth rates, poor health and high mortality.

How can colostrum quality be checked?

  • Use a colostrometer – always. You can’t accurately determine quality by eye.
  • A colostrometer is a simple piece of kit and it’s straightforward to read.Remember, your calves maybe getting enough colostrum, however if it is of poor quality, then it will have a reduced effect on boosting their health, and you’ll need to feed more.

How much colostrum do calves need? 

As much as possible, the more the better. Total volume required is around 10% to 12% of the calf’s bodyweight.

Minimum requirements: feed at least six litres within 12 hours of birth, that’s;

  • three litres immediately after birth within the first 6 hours
  • a further three litres within 12 hours

These recommended volumes are highly dependent on the colostrum quality and calf weight. A significantly higher volume of poor quality colostrum will have to be fed to offer the same level of protection as a smaller quantity of good quality colostrum

When should colostrum be fed?  

As soon as possible after birth. If you feed colostrum within the first three hours of life, that will ensure the highest absorption of the protective antibodies.

Colostrom-effect-on-mortality-FBAt birth, the calf gut is permeable, which means that it can absorb the large protective antibody molecules directly into its bloodstream. The gut then rapidly closes up, the absorption of these molecules is reduced, and by 24 hours antibodies can no longer be absorbed.

This chart shows how timing of the first colostrum feed is linked to calf mortality. Those calves fed colostrum in the first two to six hours had the best survival rate.

Margerison & Downey, 2005

Don’t forget, feeding colostrum for at least the first three days is still of value since it encourages rapid gut development and subsequently offers other benefits.

Quantity Quality Quickly Quietly

The 4 Qs of colostrum management are absolutely vital to ensure sufficient uptake of the health protecting antibodies. Here’s a reminder why.

1. Quantity: minimum three litres or six pints within three hours of birth – use a teated bottle or stomach tube to ensure the calf has received the sufficient quantity.

2. Quality: feed high quality colostrum. Always check with a colostrometer.

3. Quickly: feed as soon as possible after birth, and at latest within the first three hours.

4. Quietly: minimise stress for maximum uptake of antibodies.

For more information download our Farmers Guide to Colostrum.