CHANGE HEIFER-REARING TACTICS TO RAISE INCOME
CHANGE HEIFER-REARING TACTICS TO RAISE INCOME
Low milk prices may tempt
many to cut corners on
heifer rearing, but to do so
risks future profitability.
Jessica Buss reports
BETTER heifer rearing could improve profitability on 90% of dairy farms rearing their own replacements, through reduced costs, higher cow yields and lower culling rates.
Independent nutrition consultant Ivor Bending believes that heifer rearing is a major weakness on many dairy units, coming second only to silage making.
Getting it right could be worth 1500 litres in their first lactation, according to US research. Yet many UK farms still calve heifers at 30 months old or at too light weights, he says.
"Time is the biggest cost, but the largest impact is fertility in the first three lactations. When heifers dont calve at the right weight, then give 30 litres/day, how can you expect them to get back in calf."
Few farms have a good policy which ensures heifers reach a minimum of 350kg at bulling, then calve at 22-24 months old weighing 580kg and well grown. But the technology is available to do so.
Peter Mills, of Sutton Manor, Alresford, Hants, is seeing the benefits of a heifer rearing policy he has spent the past few years refining with Mr Bending. Last year the 45 heifers reared reached 395kg by service and will calve averaging 23 months of age.
These heifers will provide replacements for the 140-cow, 7300-litre herd, allowing numbers to increase to about 170 cows over the next few years.
Mr Mills admits heifer rearing requires careful management. "Heifer rearing is not as transparent as milk production when you can see drops as cows suffer a set-back. With heifers it is difficult to see when they are not doing well.
"It only takes one problem, such as virus pneumonia, to undo months of hard work and they may not fully recover until their second calving."
For this reason, heifers are weighed and height is measured five times in their first year and before serving (see box). This ensures they are well fed during the most critical phase of rearing, which Mr Bending believes is between weaning and five months old.
He reckons there are many successful ways to rear baby calves to five weeks. Mr Mills chooses to give calves a whey-based milk powder twice a day in buckets from four days old.
"The trick is getting calves to eat a good ration at weaning," says Mr Bending.
Mr Mills begins to offer a coarse calf mix from five days old. He could save £30 or £40/t on feed using a calf pellet, but has found calves eat the £230/t mix better and calves only eat 66kg/head up to 12 weeks old.
"Initially only half a cup, 50g, is offered and this is taken away and replaced twice a day," he says. Fresh water and straw are also offered. Uneaten feed goes to weaned calves.
When calves start clearing up feed it is increased by half a cup a feed until they are eating about 1kg, typically at about five weeks old, when they are weaned. Over the next week intakes increase to 1.6kg/day of mix, then calves leave individual pens and join a batch in a well ventilated larger shed.
Management of this shed is seen as crucial. Calves are kept well bedded with straw, passageways are scraped every day and each morning feed troughs are emptied before fresh feed is put in.
Once in this shed, calves are restricted to 1.5kg of coarse calf mix fed with a complete diet mix, designed for high yielding cows, to appetite. Feed is weighed daily and checked against target intake.
At 12 weeks old coarse calf mix is replaced with 16% crude protein calf rearing pellets costing £160/t for the next six to eight weeks. Last year an average 54kg/calf of this rearer was fed with the complete diet.
By six months old calves, being fed complete diet alone, are eating 11kg fresh weight. However, it is critical that this diet has the correct ratio of metabolisable energy to protein, otherwise calves will become fat rather than grow frame and muscle, warns Mr Bending. The ME:MP ratio of a diet for heifers is more important than the crude protein content.
Costs of rearing heifers to six months may be higher on this farm than on many dairy units. "But the extra expense is irrelevant when producing a weaned calf with a good appetite and without any growth checks," says Mr Bending.
MAINTAIN INTAKES FOR GROWTH
KEEPING heifers growing well up to bulling needs control of intakes to be maintained even when they go out to grass.
Peter Mills turns heifers out into a small paddock after first cut silage, having vaccinated them against husk and given a worming bolus. But he continues to offer a complete diet ad-lib to supplement grass.
"After second cut heifers move to a larger field, where grass intakes increase as the aftermath grows and intakes of the cow ration decrease. But this ration continues to be offered until heifers are brought in for service."
Mr Mills aims to begin calving heifers in June. But any heifers that are not 350kg by mid-September are not put in with the bull. These are given another month, then weighed again. Last October two heifers of the 45 reared had not reached 350kg by their second weighing, but they were kept with their peer group as it was impractical to keep them separately.
The bulling ration offered contains grass silage, maize silage, treated straw, rape, soya and molasses with additional minerals and urea.
Once six weeks in calf, the ration is altered to ensure heifers continue to grow frame and muscle without becoming fat. This ration needs a higher ratio of metabolisable protein to energy, explains Mr Bending.
This in-calf heifer diet is fed until heifers go out to grass. For their second grazing season they rely mainly on grass, but silage is offered during shortages. Three weeks before calving heifers join pre-calving cows. *
HEIFERREARING
• Offer concentrate early.
• Growth checks avoided.
• ME:MP ratio important.
Heifer targets
Age Height (cm) Weight (kg)
4 months 97 140
8 months 116 240
13 months 128 360
23 months 139 630
24 months 140 580*
* Post-calving
A single problem with heifers can undo months of hard work, so routine monitoring of weight, height and feed intakes is vital, says Peter Mills.