Heifer rearing delivers results on farm

John Thompsons & Sons Ltd. recognised that there was a considerable volume of new research evidence on heifer rearing, particularly from Hillsborough, which if implemented at farm level had the potential to reduce milk production costs by over 1 p/litre on all milk produced on the farm.  As a result in 2005 they developed a series of Heifer Rearing Blueprints for managing and feeding heifers born during different seasons of the year.

In order to validate these blueprints and ensure that they could be easily implemented at farm level, in September 2005 Thompsons, in conjunction with AFBI Hillsborough and CAFRE, Greenmount entered into a province-wide heifer rearing project on 8 commercial dairy farm units.  These farm units ranged in size from 90 to 400 cows.  The objective of the project was to demonstrate that the rearing blueprints, in conjunction with a simple system of measuring heifer size quarterly, could economically produce well grown heifers to calve at 24 months of age.  Heifers on each farm born after 1^st September 2005 were therefore entered ounto the blueprint rearing systems.

Project set-up

A selection of heifers within each age group (normally 5 heifers per group) were measured for size on a quarterly basis on each of the 8 farms. Progress in weight gains during the rearing period were monitored and nutritional regime adjusted where necessary.  In total, over 1,500 animals have been reared according to their appropriate blueprint with some now coming near the end of their first lactation.

Results

As can be seen from Table 1 below the average age at first calving of the 2005/06 season born heifers has been reduced from 27-29 months to 25 months of age.

Table 1.  Average age at calving in autumn-born heifers across the farms

¹ Data from all 8 farms; ² Data from 5 milk recorded farms; * Data includes completed and projected records

As expected, first lactation milk yields in the recorded farms have been reduced (by approximately 150 litres) (Table 1), however projected calving interval records show an improvement in fertility performance, key in meeting the target lifetime yield of 30,000 litres, a figure which is well above the national average of approximately 25,000 litres.

Monitoring Progress

Tracking heifer growth performance through quarterly measurement highlighted a number of issues.

• Quality of winter forage had a significant effect on the ability of heifers to meet targets when fed according to the blueprint recommendations.

• Equally periods of difficult grazing conditions either in grass quality or quantity significantly impacted on performance.

• If not recognised early, these periods of poor growth resulted in heifers not achieving targets and subsequently incurred increased feeding costs.

• It is also important to recognise periods of over nutrition where excess fat will be laid down.This is common on high quality silages where concentrates continue to be fed and is detrimental to long term heifer performance as well as adding unnecessary cost to the system.

For example, a yearling heifer given a very good quality silage (high ME content and good intake potential) can achieve 0.8 kg/day when supplemented with only 0.5 kg concentrate/day. In contrast with a lower quality silage, 3.5 kg concentrate will be required to achieve the same target growth rate. There are therefore massive opportunities for making savings in heifer rearing costs through ensuring that they receive good quality silage where at all possible. Unfortunately, on many farms the heifers are allocated the poorer quality silages and hence will require higher levels of concentrate supplementation.

To provide farmers with guidance on the necessary levels of concentrate required with differing silages, Thompsons are now providing concentrate feeding guidelines for heifers of different ages on all their silage analysis reports.

Similar opportunities arise when calves/heifers are at grass. This is particularly true when animals are in their first year at grass. In the majority of grazing systems, young calves at grass will require concentrate supplementation. However if calves can be grazed as a leader group, in which they can select the higher quality grass leaf and leave the lower quality material to be grazed by older stock, then concentrate levels can be reduced - or even eliminated

An additional, and vital, factor in management at grass is the need for a robust approach to the control of parasites. A good grazing season can be quickly ruined through a relatively short lapse in parasite control. While this particularly applies to young calves it can be equally important with older animals.

Key Messages

• Blueprint rearing systems ease management decisions.

• The systems presented here have been validated on 8 farms with 1500 heifers.

• During winter, silage quality dictates the amount of concentrate required to acheive 0.7-0.8 kg liveweight gain/day.

• Thompsons have now introduced a “Heifer Concentrate Feeding Recommendation” on all their silage reports.

• Grazing systems can be extremely variable and often cause many problems.

• Monitoring growth rates and adjusting feed accordingly is the key to success and cost reduction in heifer rearing.