Tips for unlocking growth in dairy-cross calves

Moving to an accelerated milk feeding program and better weaning management may be two of the biggest opportunities Ontario veal producers have to improve performance in dairy-cross calves.

This stems from research presented by University of Guelph PhD candidate Titouan Chapelain during Veal Farmers of Ontario’s Producer Education Day.

In traditional feeding programs, calves are offered milk twice daily, and starter from an early age to encourage rumen development; new research is suggesting, however, that this approach could be leaving growth on the table.

“Early growth matters,” Chapelain said, linking calf performance in the first weeks of life directly to cost of gain.

In fact, growth problems early on become an “economic burden,” especially during the more costly milk-feeding phase, so the goal for producers should be to help calves get a strong start so they can grow steadily, stay healthy, and come through weaning without a setback.

The first key to success is colostrum management. Chapelain stressed that while producers buying calves may not control what happens at birth, they are the ones that will be impacted by the consequences. Good transfer of passive immunity depends on colostrum quality, quantity, and timing.

This means colostrum above 22 Brix or 60 g/L IgG, fed at more than 10 per cent of birth body weight in the first 12 hours, with the first meal within one hour of birth. Calves can then be classified on arrival by serum total protein, ranging from poor to excellent transfer of passive immunity.

Calves with weaker passive immunity are more likely to struggle, he noted, and showed data indicating dairy-cross calves outperformed Holsteins in several areas.

This includes lower diarrhea risk, fewer repeat respiratory treatments, higher starter intake around weaning, and stronger body weight and average daily gain; in some growth measures, they outperformed Holstein calves by three, six, and seven kilograms.

Veal producers should therefore both work closely with their calf suppliers to understand colostrum practices and assess calf status on arrival whenever possible.

“If you see calves not performing well then you can probably go to your supplier of calves and discuss with them,” Chapelain said.

A growing body of research is suggesting that feeding colostrum beyond the first day of life was linked to lower diarrhea risk, improved average daily gain, and higher starter intake, with some studies also showing reduced duration of diarrhea and pneumonia.

Separate work using colostrum at the onset of disease was associated with faster diarrhea resolution and greater gain, and although researchers still need to refine the best protocols, Chapelain suggested discussion about colostrum supplementation would likely become more common.

The bigger challenge to long-standing calf-feeding practices relates to milk volume, however. Calves are generally offered milk twice daily, and starter from an early age to encourage rumen development, but different approaches could be getting calves off to a better start, according to various research results.

One study showed that moderate milk intake helped calves compensate for poor transfer of passive immunity, while low milk intake reduced growth potential in calves with good immunity and was especially harmful for calves with poor immunity.

Another trial found calves fed 10 litres per day instead of five had increased average daily gain and body weight, along with reduced cost of gain in the first two weeks. A separate comparison of four versus eight litres per day showed a 22-kilogram body weight advantage and an 85 per cent heavier liver in calves receiving the eight litres daily, underlining how deeply early feeding can affect development.

While it’s not realistic to expect veal producers to feed 10 litres a day, Chapelain did urge them to think about finding a workable middle ground.

“Feeding low volumes of milk replacer is enough for maintenance but not for growth, whereas moderate to high volumes are an investment that could pay off long-term,” he noted.

It is possible that milk composition may matter too, but more research is needed to draw definitive conclusions in this field – and there is currently no milk replacer formula tailored specifically for dairy-cross calves.

Starter feed is another piece of the puzzle, but again, hard recommendations are limited for dairy-cross calves. One caution was clear, though: starch above 40 per cent of dry matter raises the risk of acidosis so if feeding high-starch, finely ground or pelleted diets, some forage is recommended, but it should stay below 10 per cent of daily intake.

“Weaning is the key,” he said, adding that even strong early feeding programs can be undermined by weaning calves too early or too abruptly.

Calves move at weaning from getting energy through milk digestion to getting it from rumen fermentation. If that transition happens before starter intake is high enough, calves can lose energy intake and growth.

A few takeaway tips for producers:

• do not fully wean before eight weeks of age,
• stretch the weaning process over at least two weeks,
• step calves down gradually,
• only cut off milk when they are eating 1.5 kilograms of starter per day for three consecutive days.

“Feeding moderate to high volume of milk replacer is an investment that pays off long-term,” Chapelain said. “Weaning can make calves thrive or sink so plan your weaning protocol wisely.”

Producers are encouraged to discuss weaning protocols with their veterinarian or nutritionist as part of overall herd management strategies.