Ensuring heifers are reared properly can boost milk output by
up to 1000 litres/year. Promars principal dairy consultant
Diana Allen reports from a recent tour of US units
YOU could question how relevant Californian dairy farming is to UK producers. There are obvious differences, such as climate and abundance of cheap by-product feeds, but cows are of similar genetic merit to our top UK herds and there are lessons to be learned.
They are also going through a tough time with milk prices at about 14.45p/litre, well below the cost of production. Everyone I met was losing money.
I toured nine dairy units ranging in size from 700 to 4350 milking cows. What impressed me was the care at every stage of the heifer rearing process.
This isnt surprising, as the difference between good and poor heifer rearing equates to between 500 and 1000 litres/year extra milk production. I believe its essential to ensure heifers are large enough to withstand bullying and compete with other cows.
Calves were kept on whole milk longer than in the UK and suffered fewer checks in growth rate. This is because they were fed a consistent ration from three months to two years of age and kept in uniform batches.
UK heifers often experience growth checks, particularly when put out to grass or ignored in a field. All heifers were being reared to calve at 24 months.
Of the nine units, eight reared their own replacements. The one that wasnt rearing calves sent them at one day old to a partner business, rearing 10,500 calves to 120 days of age before sending them back to the various owners farms.
Bull calves were typically sold at one day old. One unit was selling day-old Jersey bull calves for £3.33 for hide. Holstein bull calves at the same age were being sold for £33.55 and £57 on two other units. Only 18 months ago, bull calves were worthless.
Producers house calves in hutches, some with open bottoms and others with slatted floors. Slatted hutches were used inside buildings or outside on concrete. Open floor ones were generally laid on flattened soil and bedded with either dried manure, rice hulls or almond shells.
On the large calf-rearing ranch, slatted hutches were placed in groups of four on concrete. There were 6000 hutches in rows on a relatively small area.
Hutches are steam cleaned between batches of calves and moved onto a fresh area of soil or concrete. Producers then apply lime on the old area to kill any bugs. Fly control is a general problem, but spraying hutches regularly seems to reduce animal discomfort.
To ensure a good start, calves are given 3.8 litres of colostrum by tube within an hour of birth. All farms store frozen colostrum. The importance of colostrum is a message that seems to have been taken up by Californian dairy producers.
The calf rearing ranch weighs and blood tests each calf as they arrive and the test results are sent back to farm of origin to aid management by indicating the level of colostrum calves have been fed. In a large rearing unit, lack of early colostrum increases death rates considerably.
Calves are fed whole milk by either bottle or bucket and weaning is not until three months. At the calf ranch, 4500 calves were bottle-fed 3.8 litres of milk twice a day.
All the units I visited kept freshly calved cows separate from the herd for 10 days and milked them in a separate mini parlour or milked them last through the main parlour. All hospital cows were also placed in this group.
Their milk is put in a separate tank and pasteurised before feeding to calves. All units have their own pasteuriser and they are convinced it is essential for maintaining good calf health. One producer tests nutrient density of the tank milk regularly using a refractometer and adds milk powder when necessary to increase its density.
Calves also receive a highly palatable molassed course mix. Bottle fed calves have water available all the time and bucket fed calves receive water after each feeding.
They have no access to hay, straw or silage while on milk, therefore, relying on the course calf mix to aid rumen development over the 12 weeks.
Calves sucking each other after weaning can be a problem, but one producer withdraws milk two weeks before removing calves from the hutches and placing them in groups of 25. Since starting this practice, there has been no heifer sucking.
All heifers are grouped according to age and fed a mixed ration. Typically, the ration consists of alfalfa hay, sugar beet shreds and soya. In addition to this base ration, younger calves at 3-6 months of age receive 2kg/day of grower concentrate on top of the ration to boost energy and protein content (see table).
California grows a large array of fruit and vegetables producing much cull fruit, which ends up in dairy rations at no cost. I saw heifers eating fresh peaches, nectarines, melons and grapefruits. Stones are not a problem, as they spit them out.
Heifer handling is made relatively easy by housing animals in open corals with locking yokes on the feed barrier. Yokes are sized according age and heifers soon acclimatise to them within a few days.
All farms visited are artificially inseminating heifers with dairy breed semen. AI is an easy task with the self-locking yokes. Rearers examine heifers each morning and apply fresh tail paint. Sweeper bulls are only put in with the in-calf heifer group to catch any abortions.
To minimise animal losses, US producers employ specialist labour with the sole task of rearing calves. Calf mortality rates are consistently low at 3-4% per year across the nine units, less than half the UK average at 9%.
At the calf ranch the calf feeders earn the basic minimum wage of £4.70/hour and work nine hours a day. They walk about 10 miles daily up and down the rows of calf hutches.
When they are promoted to stockmen, they can earn bonuses for low calf mortality and low drug use. There are currently 60 men on the ranch looking after 10,500 calves.
On another unit, there were two full time men on calf rearing. There are 530 calves fed milk at any one time. Both these men had been on the farm for over nine years and had been trained to do nothing but calf rearing. *
Calves are often kept in individual slatted floored pens until two weeks after weaning at three months of age.
US producers believe pasteurising milk is essential for maintaining good calf health, says Diana Allen.
Californian milk producers feed calves pasteurised whole milk, often in bottles, twice a day, until they are three months old.
Age group (months) +3-6 7-13 14-17 18-22
Dry matter (%) 66.0 42.0 41.0 41.0
Protein (%) 18.9 16.2 15.2 15.2
ME (MJ/kg DM) 10.5 9.3 9.2 9.2
Neutral Detergent Fibre (%) 31.4 47.4 49.0 49.0
Cost (p/head/day) 50.0 60.0 67.0 73.0