There is frequent discussion on social media about how much milk to feed calves.
There are many opinions as to the right answer to the question and, in part, the answer to this question depends on the ultimate fate of the calves being reared.
Nature gives us clear indicators of how much calves should be fed in the first few weeks of life. Calves left to suckle their dam will be consuming around 15 litres/day within the first couple of weeks of life. This is very different from what calf rearers have been led to believe are acceptable feeding levels.
It has been proven beyond doubt that replacement heifer calves that are fed biologically normal quantities (20 per cent of body weight) of milk early in life:
- have better health outcomes as pre-weaned and post-weaned calves;
- have higher growth rates in early life;
- produce more milk over their lifetime;
- get in calf more easily; and
- have a lower cull rate before their second lactation.
Using restricting feeding levels will almost certainly result in sick or dead calves. This is illustrated in a recent quotation from a social media site which sums up the often-overlooked issues with restricted feeding. "We do 2 and 2.5 then 3 x 2 for a few weeks before weaning at approx 10 weeks. . . . I've dropped one feed for some and seperate the skinny ones. We had a really bad sickness also, so will keep milk up a bit longer." [sic].
READ MORE: Get the basics of calf rearing right
Assuming a birthweight of about 40 kilograms, this person's calves would have been getting barely enough nutrients to allow for growth; remember that if the body is not growing, nor is the immune system developing.
I use this example to illustrate the lack of up-to-date information among rearers. In no way do I condemn the person, in fact, I believe they joined the social media group to improve their skills, for which I respect them. There is such a proliferation of differing advice about feeding that there is no wonder that novice rearers find it hard to decide on the right choice for their enterprise.
In the instance above, I suspect the rearer had not understood the correlation between low feeding rates and the outbreak of disease. The fact that the rearer had underweight and sick calves is a good indicator that the feeding system is not supplying enough nutrients to allow the calves to be healthy.
People tend to focus on the cost of the milk, without looking at the big picture - is the amount of milk fed sufficient to allow the calves to meet health and growth targets and to prevent the calves from exhibiting the abnormal behaviors associated with under-feeding (cross-suckling, excessive vocalising, etc)?
It is quite common to see calves on restricted feeding programs lose weight in the first month of life. This predisposes calves to infectious diseases such as salmonella, E. coli, crypto in the first couple of weeks and later, pneumonia, simply because their immune systems are not robust enough to fight the infections.
READ MORE: Strict control key for calf rearing
The calves are not consuming enough nutrients to develop their immune systems. Ensuring that calves do not drop below their birth body condition score is an effective way of quickly assessing whether or not calves are receiving enough nutrients. Setting growth targets and regularly weighing calves is even more reliable.
The costs associated with any sick or dead calves (for example, calf value, extra labour, vet visits, medications, reduced feed conversion) must be factored into the total budget. A system delivering healthy calves with a mortality rate of less than 1pc, a morbidity rate of less than 5pc and that achieves early life growth rate targets is the most economic feeding system. If it means increasing the milk feeding rate to achieve this, it will still be more economical than the costs associated with higher mortality and morbidity rates. It will also deliver acceptable animal welfare outcomes, which underfeeding does not.
Even with calves reared for beef, the cheapest way to feed them is the one which results in the healthiest calves. This is likely to be the system that offers more than or equal to 8 litres per day for at least the first few weeks of life. This approach will deliver healthy calves and good animal welfare standards. Grain consumption can be encouraged by gradually feeding more of the milk ration in the morning and less at night. Providing a suitable dry feed is available ad lib, calves will start to fill the nutrient gap with grain, which will develop their rumens in time to allow weaning at 6-8 weeks.
When selecting a calf milk replacer, remember that very young calves do better on a skim based powder and that the cheapest product does not always deliver the most economical result. Relating back to the quotation above, if underweight calves are a regular occurrence, the milk feeding levels should be revised to deliver a better body condition score. If sick calves are a regular occurrence, review milk preparation protocols and hygiene of feeders and calf environment, then revise milk feeding levels.
Remember, feeding more milk does not make calves scour but feeding more bugs does.
*Jeanette Fisher is principal of specialist heifer rearing consultancy HeiferMax. She can be contacted via its website www.heifermax.com.au.
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