Calving heifers at a younger age is a much debated subject and research has shown that this practice makes sense financially.
At a meeting for YVN sponsored by Zoetis and Trouw Nutrition, Aurelie Moralis, Veterinary Consultant with Zoetis pointed out that heifers don’t become profitable until halfway through their second lactation, but 14.5% of dairy heifers fail to reach their first lactation.
Dr Mark Little, Trouw Nutrition emphasised that heifer rearing remains the second biggest cost of dairy farming. This cost could be reduced considerably by calving heifers at a much earlier age which requires high growth rates early in the pre-weaning phase.
The key scientific principle for this is metabolic programming, i.e. how an animal is managed in early life, affects the rest of its productive life.
With this in mind, Trouw Nutrition communicates this through the concept ‘LifeStart sets Life Performance’.
Studies have shown that when calves are fed a high plane of nutrition from between two and eight weeks of age this resulted in an increased development of key organs, including the mammary gland, resulting in higher milk yields. These calves were laying the permanent foundation for a more productive life as a cow.
However, it is important to consider the formulation of a calf milk replacer if it is to be fed at higher levels. Based on considerable research, Trouw Nutrition have developed a specific formulation for LifeStart milk replacers which ensures the correct protein content, amino acid composition, precise fat content and raw materials.
This allows feed rates of at least 900g/day of milk replacer to be fed safely to encourage faster, healthier growth.
Aurelie Moralis stressed that disease control also plays a vital role. “Pre-weaning pneumonia has been shown to reduce growth rates by 3 to 9% despite compensatory feeding and reduce first and second lactation yields by 4 and 8% respectively.
“The secret is to have immunity in place before the challenge for example vaccination with Rispoval® IntraNasal provides protection from two weeks of age and the 12 week duration ensures cover over the critical pre-weaning period when disease can impact growth rates, age at first calving, subsequent milk yields and longevity.”
Aurelie concluded her presentation highlighting the importance of fertility management to achieve the desired calving age of 24 months.
She stated that breeding protocols based on CIDR® in conjunction with prostaglandin and GnRH provide the opportunity for Fixed Time AI, maximising submission rates and ensuring all heifers are served at the appropriate time.
Jamie Robertson, Livestock Management Systems, outlined the role of the environment on calf health stressing that problems in livestock buildings are usually due to imbalances in one or more of three separate factors – moisture, fresh air and air speed.
Other factors to consider are the impact of lower critical temperature on young calves and the importance of hygiene during the rearing period.
Jason McFerran, Dairy Business Technologist with CAFRE informed the meeting that the 2015/2016 benchmarking results showed that the cost of production for rearing a heifer was £1528 per head for the top 25% of farms while the bottom 25% had a cost of £2419.
Evidence from benchmarked farms also highlighted that the top herds calve heifers earlier – they are aiming to serve at 13.5 months weighing 350 to 370 kg.
Jason added: “Benchmarking won’t make you money but it will show you where it is going!”