Recent months have been marked by an intensive series of advisory messages from a number of organisations espousing the benefits of calving replacement dairy heifers at 24 months. However, this is a message that Dr Jud Heinrichs, from Penn State University in the US, has been communicating proactively for many years.
In fact, his research work in the US has shown clearly that it is feasible to successfully calve Holstein heifers as young as 23 months. The renowned agri academic was in Ireland earlier this week. However, he took time out of his busy schedule to speak with AgriLand.
“On farm results have confirmed that it is more than feasible to calve heifers successfully at 24 months,” Dr Heinrichs explained.
“As a consequence herdowners will reap the benefits of a longer milking life, combined with the tremendous advantage at the other end of bringing replacements into the milking group at a significantly younger age.
“The secret in meeting this objective is to ensure that the young animals reach their growth targets from birth through to calving.”
He continued: “Total attention to detail is required throughout this process, which commences with the feeding of 6 litres of high quality colostrum to the newborn within the first twelve hours of life. Thereafter, milk should be offered twice daily.
“It is crucially important that a high-quality calf starter, in tandem with fresh water, is offered from day four, in order to maximise rumen development. Research has shown that young heifers can achieve daily liveweight gains of 0.8 kilos per day between the ages of three and 11 months. These optimal growth rates can be achieved by feeding a mix of either silage, or grazed grass and up to three kilos of heifer rearing nuts per day.”
Heinrichs went on to point out that during the second year of the animal’s life concentrates can be used, as required, to ensure that her energy and nutritional levels are such that she has a body condition score of between 2.75 and 3.0, one month before calving..
He concluded: “Research has shown that increased concentrate intake will significantly enhance rumen development in young calves. This, in turn, will ensure that the animals will make optimal use of forages throughout their lives.
“It is only in the past five years that the attention of researches has been focused on identifying, more completely, the management needs of growing dairy heifers. This ongoing work will, undoubtedly, shed new light on this fundamentally important aspect of milk production during the period ahead.”