Heifers eat more separated from cows
FIRST lactation heifers eat more each day when they are kept separate from cows; this should improve performance and ensure more stay in the herd for a second lactation.
So believes Jealotts Hill Farm, Bracknell, Berks, herd manager Mark Osman. The herd has a low culling rate of 19%. But on closer examination he found that over the last few years 36% of heifers introduced to the herd failed to reach a second lactation. This is similar to national statistics revealed recently.
Reasons for heifer culls included low yields, and low fat and protein percentages. Daughters of the Dutch bull F16 fared badly in particular, with 31 of 36 culled over three years, many of which were in their first lactation.
"This bulls daughters couldnt hold body condition on our low concentrate system, and were slow to put on condition before their second calving," says Mr Osman.
Heifers calving in early spring, though fewer in number, had performed better last year, giving 6800-litres, than summer calvers who averaged 5600-litres. The extra production of the spring calvers was not explained by higher genetic potential; it must be because they suffered less competition for feed in early lactation than the summer calvers.
Mr Osman is, as a result, convinced that excessive heifer culls result from poor feed intakes at a time when animals need to gain 70-80kg in bodyweight before their second calving.
This autumn he separated the 36 summer calved heifers from the milking cows and their intakes increased by 2kg DM a head over the first few days to 19kg DM/head – off 4kg of concentrate and a mix of three forages. The heifer diet is designed to overfeed in the first 100 days of lactation, supplying maintenance plus 25 litres; actual yield averaged 19 litres at housing.
"The heifers have settled down as a group and are very calm. In fact, they are now the best group to milk – they come into, and go out of, the parlour easily without any feed being offered," says Mr Osman.
• Separate in first lactation.
• This will increase intakes.
• More will complete second lactation.