Heifer rearing costs represent the second highest cost on dairy farms after feed, with costs ranging from 13-20% of total milk production costs.
Calving at between 22-24 months reduces rearing costs and results in greater lifetime performance and reduced metabolic issues at calving compared to calving at a later age.
To maximise efficiency, aim to calve a heifer at between 22-24 months of age at 85-90% of the mature bodyweight of the herd.
To achieve this, it is essential to achieve target growth rates in the pre-weaning period, and calves should double their birth weight by weaning at eight-to-10 weeks of age.
Colostrum – Quality, Quantity, Quickly
Probably the most important part of calf management is getting quality colostrum into calves quickly and in the correct quantity.
The calf is born with very few energy reserves and colostrum is a rich source of nutrients during the early stages of life.
More importantly, calves are born with an undeveloped immune system and new-born calves depend on the passive transfer of immunity from colostrum (immunoglobulins-IgG) to protect themselves from infection and disease until their immune system can start to develop its own antibodies.
- Test colostrum quality with a Brix refractometer.
- Feed colostrum with more than 50g/litre of IgG at a rate of 10% of the calf’s bodyweight within four hours after birth, to achieve a minimum of 10g/litre of IgG in the calf’s plasma by 24 hours after birth.
- Typical feed rates are 4-5L per calf but this will depend on IgG content.
- Colostrum should be fed as soon as possible after birth as IgG absorption rates reduce by 60% six hours post birth.
- Don’t let calves suckle their mothers as there is no way of knowing the quality or quantity of colostrum consumed, and there is a risk of contamination from dirty teats.
If insufficient or poor quality colostrum is provided, or it is not provided quickly enough after birth, then failure of passive transfer of immunity can occur.
This increases the calf’s susceptibility to respiratory infection and pathogenic diarrhoea. Poor calf health during the pre-weaning period has been shown to affect lifetime performance.
Milk replacer
It is important to promote high rates of daily gain with milk replacer early in life but also not to over-feed as it can reduce or delay starter feed intakes, which are vital for rumen development.
A 45kg calf requires approximately 380g of milk replacer (3L fed at 125g powder/litre) for maintenance alone, with any additional milk intake being utilised for growth.
As an easy rule of thumb, provide 1.5% of bodyweight as solids during the first week of life, increasing to 2% of bodyweight from the second week of life until the week before weaning.
Starter feed intake
It is vital to promote early intake of starter feed to develop the rumen so that the animal can start to digest fibre.
Don’t forget the importance of clean, fresh water provision either!
Promoting high rates of starter feed intake is essential to produce Volatile Fatty Acids (VFAs), which are the result of rumen fermentation of carbohydrates.
These VFAs, and specifically propionic and butyric acid, are vital for the development of the rumen papillae, which are essential for nutrient absorption from the rumen.
Fresh starter feed should be fed daily and target 300g of starter feed intake by three weeks of age, of a feed that contains >32% starch, high quality protein (with good levels of UDP) and low digestible fibre.
Feed a source of forage as 4% of total solid feed, chopped to 2.5cm and containing >65% NDF (e.g. chopped hay or straw) as this promotes muscular development of the rumen thereby facilitating higher intakes of starter feed.
A source of chopped forage will also aid rumination which will contribute to raising rumen pH above a pH of 6.0.
This should promote the increased intake of starter feed.
A typical recommendation is to wean Holstein calves once they are consuming 2kg of starter feed per head per day for three consecutive days.
Video: Managing calf rearing – from birth to weaning
Benefits of using Actisaf
Including Actisaf Sc47 protected live yeast in the ration provides significant benefits to calves during the pre-weaning stage.
Actisaf reduces oxygen levels in the rumen and creates an environment where the main cellulolytic bacteria will grow and thrive, thereby improving fibre digestion and enhancing the development of rumen flora.
Actisaf also eases the transition on to starter feed, as it conditions the rumen microbes for the change in diet by biologically buffering the rumen and promoting a higher rumen pH through the stimulation of lactic acid-utilising bacteria.
Trials have also demonstrated that when supplemented during the pre-weaning period, Actisaf increases average daily gain and feed conversion efficiency, which ultimately can reduce the days to weaning.
Using Safmannan in diets
Feeding Safmannan, has been shown to greatly enhance calf performance, and it is particularly pertinent with the increasing focus surrounding antibiotic usage and subsequent resistance in calves.
Safmannan is a premium yeast cell wall, manufactured from unique strains of yeast under extremely consistent manufacturing conditions.
Beta glucans and mannans – the functional properties of Safmannan – strongly support the immune system of the calf, thereby strengthening its defence mechanism to challenges.
Safmannan also promotes the growth and repair of the intestinal villi, ensuring that nutrient absorption from the lower gut is maximised, while also binding to specific bacterial pathogens that may enter the calf’s gut, thereby reducing the calf’s susceptibility to scours.
Supplementation with Safmannan daily during the pre-weaning period results in stronger, healthier calves that exhibit greater growth rates.
A farmer’s perspective
Dairy farmer, Jim Scott, has been pleased with the benefits he has seen from feeding Actisaf live yeast to his cows.
So, when he heard about a calf bucket that combines Actisaf with Safmannan premium yeast fraction, he was keen to find out more.
Jim Scott
Jim now feeds Actisaf and Safmannan as supplements to calves, which he buys as a pre-mixed calf bucket and he adds into milk as soon as they are taken away from the mother. To find out how Actisaf and Safmannan has worked on Jim Scott’s farm click here
