First lactation
The policy adopted when managing a first lactation heifer can have a large impact on subsequent performance. First lactation heifers are adjusting to a new environment but are still expected to milk, grow and breed successfully. Data from ADAS has indicated that milking heifers fed in competition with cows are likely to produce less milk in their first lactation and have a higher chance of being culled before their second lactation than heifers fed separately. Measures should be taken to minimise the stress encountered by the first lactation heifer. Steps which are taken at Greenmount Campus include:
First lactation heifers are housed and fed separately from the main herd. This strategy has been used successfully at Greenmount Campus as it allows first lactation heifers to settle into the milking herd and avoids problems such as bullying by older cows. Where this is not possible ensure that adequate feeding space (350 - 450 mm per animal) is available for all stock.
Figure 3. Silage Intakes at Greenmount Campus.
Silage intake measurements carried out at Greenmount Campus have shown that first lactation heifers eat less than cows (Figure 3). As a result milk production levels from forage are set so that heifers are fed more concentrate than cows for a given level of milk produced.