Ongoing Agri-Food and Biosciences Institute (AFBI) research is again confirming the importance of dairy heifers calving down successfully at 24 months of age.
It’s an approach that ticks every box: two year old heifers that have reached their proper weight targets are more likely to achieve higher lifetime milk outputs. This level of performance is a direct consequence of the animals’ inherently high health and fertility traits. And, from a genetic and environmental perspective, is also makes a positive difference to the ongoing sustainability of any dairy farming operation.
So much for the theory: making this happen in practice requires high standards of management on the part of the farmer from the very instant the calf is born.
United Feeds have advocated 24-month calving for many years, but with a new calf rearing season underway on many farms they’re keen to refocus on how nutrition plays a huge role in achieving the goal.
United Feeds nutritionist Jenny Hamilton takes up the story:
“We addressed this challenge from the perspective that replacement heifers can be calved down at 24-months successfully if we build a strong immune system, develop the rumen and meet growth targets at all stages. With that in mind we developed a heifer rearing programme a number of years ago alongside a range of bespoke calf milk replacers (CMR) and youngstock rations to ensure that calves can meet their growth targets comfortably.”
Jenny made these comments during a recent visit to the Gilford farm of Colin and Mark Spence. The father and son team supply Dale Farm, milking 300 cows in tandem with a farm contracting business.
Colin and Mark have always reared their own replacements. But, at times, not enough heifers were coming through. As a consequence, recent years have seen them focus more on calf rearing and achieving a 24-month calving target. This approach, in tandem with the targeted use of sexed semen, allows them to sustain cow numbers around the 300 mark.
Jenny continued, “Calves are fed Advance CMR at a rate of 900-1000g/head/day. The recommended mixing rate is 150g of powder per litre of milk drunk. Calves are most efficient in their first three months of life, converting on average 55% of their feed into growth, so firstly it makes economic sense to maximise growth during this period. Secondly, with evidence that greater growth pre-weaning positively influences the capability for milk production it makes nutritional sense. Growth, not just in terms of bodyweight but crucially organ development; notably the liver and mammary tissue.
That said, we want growth rates to continue after weaning, hence rumen development is a core objective of our youngstock rations. At Spence’s Advance calf starter pellets, in tandem with fresh water and adequate straw, are also made available to calves from the beginning.”
Colin confirmed that, despite the high rates of milk replacer consumed, calves are quick to get onto the starter pellets.
“This would be a common remark from customers,” Jenny added. “Greenline contains butyrate and specific sugars known as ‘a mother’s smell’. The Greenline flavour link between Advance CMR and the Advance starter pellet was conceived to encourage feed intakes. It is very heartening to hear so many customers, including Colin and Mark, confirming that this is being achieved in a commercial, on-farm setting.
In addition, Greenline contains additives for the nutritional maintenance of the immune system through an increase in the defensive mucus intestinal lining, inhibition of bacterial attachment and deactivation of mycotoxins. Other additives create an optimal rumen environment for epithelial development and microbial growth, increasing rumen function through both absorptive capacity and efficiency.
Ultimately Greenline increases the calves feed conversion ratio, optimizing growth performance and liveweight gain.”
Once weaned, the calves on the Spence farm are moved on to Advance Heifer nuts.
“Amaferm® is a key component of our Advance calf range,” said Jenny. “It stimulates the fungal & bacterial microbes leading to more digestion, specifically fibre. Establishment of this microflora is critical to developing a functional rumen capable of fermentation. Calves fed Amaferm have been shown to have increased VFA production, increased ruminal bacterial counts, higher starter feed intakes and increased liveweight gain than calves not fed Amaferm.”
“The inclusion of Bio-Mos® in both rations also develops gut integrity by promoting good bacteria and building the calves natural defences to boost immunity and reduce the incidences of scour.”
“We are targeting rumen development and health through nutrition to drive growth rates and it’s great to see the final outcome in a uniform batch of heifers that are due to calve over the coming weeks,” said Jenny.
Mark commented, “We find that 24-month heifers have better fertility in that, as second calvers, they are easier to get back in calf when compared with their older counterparts. This is a consistent batch, we’re looking forward to getting them calved.”
