Heifer rearing is often seen as a high cost enterprise but it should be seen as an investment rather than a cost and if animal health and performance is prioritised, farmers will reap the awards through a return on investment.
Senior dairying development adviser with the College of Agriculture, Food and Rural Enterprise (CAFRE), Alan Hopps said: “If heifer rearing is prioritised, heifers can calve at a younger age, produce more milk in their first lactation, and remain productive on the farm for longer.
“This not only reduces the need for land due to fewer heifers present on the farm, but it also lowers the carbon footprint and enhances overall farm profitability.”
As calving season kicks off for spring-calving herds and with all-year-round calving farms focusing on weaning autumn calves, the health and wellbeing, performance and growth targets and general management of your replacement heifers need to be a priority.
Heifer targets
Hopps said that the age of first calving is the first crucial step in meeting heifer targets as he highlighted that heifers should calve at 22-24 months.
Calving too early can lead to ‘calving pattern creep’ causing heifers to calve outside the herd’s calving window if not managed properly.
For all-year-round calving herds, calving at 21 or 22 months is not an issue if heifers are well grown.
Hopps highlighted that farmers should aim for a 90% retention rate of heifers which means retaining heifers to calve again in the herd for a second lactation. Heifers leaving the farm during their first lactation won’t cover their rearing costs.
In terms of milk yield, heifers should exceed 80% of mature cow yield in first lactation. For instance, if the herd averages 8,500L, heifers should produce over 6,800L, maintaining an average herd yield of 8,000L overall.
When it comes to weight at service, heifers should reach 55-60% of their mature weight by service.
For a herd averaging 650kg, heifers should weigh around 360kg at breeding, which can start at 13 months if they meet the target weight.
This should lead to heifers calving down at 85-90% of their mature weight. A herd with an average weight of 650kg will mean that heifers should weigh at least 550kg at calving.
Heifer rearing
Hopps also highlights crucial factors for a successful heifer-rearing enterprise starting with careful sire selection.
The CAFRE adviser urged farmers to always choose sires with a higher potential transmitting ability (PTA) for milk than the herd’s average to ensure progress in improving the milk yield potential of the herd.
He said that a herd with a PTA of zero, on average, will still have the potential for a herd yield of 9,000L.
Other elements of a bull’s figures which are important to consider are longevity, fertility index and components. Functional type should also be considered to help ensure a longer herd life.
The rearing phase is very important and it is crucial that the heifer calf gets 3-4L of colostrum straight away as it is the most important feed of its lifetime and vital for its future.
Following this, a milk feeding regime should ensure optimal growth, with peak calf milk replacer feed rates exceeding 1kg per calf per day or 8L of whole milk.
Reducing diseases such as scours and pneumonia during the rearing period is essential and farmers should work with their vet to create a vaccination programme and ensure hygienic, airy housing to promote growth.
Aim for an average growth rate of 0.8kg/day from birth to calving, maintaining consistent growth throughout the heifer’s life if possible.
Hopps said: “If you don’t measure something, you can’t manage it,” adding that “an interactive programme on the online services section of the DAERA [Department of Agriculture, Environment and Rural Affairs of Northern Ireland] website, under the BOVIS heading, allows you to track heifer performance against your targets”.
The importance of regular weighing cannot be underestimated as Hopps said: “If heifers lag behind target, nutritional adjustments can be made to help them catch up.”
The CAFRE adviser said that “some of the best heifer-rearing farms in Co. Armagh are achieving average first-lactation milk yields of 10,000L, with an average lifetime yield of 45,000L”.
These heifers on the farms that Hopps mentioned have a weight at calving of 650kg and a conception rate in their first lactation of 54%.
He said that “while not all farms will target such high yields, this demonstrates the potential achievable with excellent genetics and careful management of your heifer enterprise”.
