“Unless we improve dairy cow efficiency we are going to fall behind in protein production, and the rate of growth of young calves is correlated with future milk output,” said Dr Alex Bach, research professor, Department of Ruminant Production, IRTA, speaking at the Phileo Lesaffre global ruminant symposium in Toulouse last week.
He said, more often than not, heifers are managed based on ‘feeling’ rather an approach based on methodical data collection and record keeping.
“However, today, it is clear that nutrient supply and hormonal signals at specific windows during development, both pre and early post-natal, may exert permanent changes in the metabolism as well as changes in performance, body composition and metabolic function of the offspring of livestock.
Results from a meta-analysis concluded about 225 kg of additional milk in the first lactation could be expected for each additional 100g per day of growth during the first two months of life,” said Bach.
He said achieving greater calf growth in early life requires a hike in the amount of milk replacer or milk being fed. However, he noted calves fed eight liters per day may compromise their starter intake and if milk replacer is given only twice a day insulin resistance could develop in the calf.
“In addition, calves fed high milk allowances tend to struggle during transition onto solid feed and part of the growth advantage thus could be lost due to diminished consumption of nutrients,” said the Catalonia based ruminant specialist.
Rumen development
Therefore, feeding six liters of milk replacer or milk daily three times per day is most likely the best approach for the calf in terms of rumen development, solid feed intake and digestion efficiency, stressed Bach.
Promoting solid feed intake is a critical part of the higher plane of nutrition feeding strategy, said Bach. And he said starter feed consumption can be improved by including palatable ingredients in its formulation.
Also an effective way of fostering solid feed intake in calves, contrary to traditional advice, is to provide ad libitum access to chopped straw or chopped grass hay of poor quality nutritionally as this can increase solid feed consumption by 23% with subsequent growth benefits, said Bach.
“In terms of weaning, if producer want an average daily gain of around 1kg per day, calves should not be weaned until they eat at least 2kg of dry feed. Weaning with intakes below is possible but growth, and potentially health, will be compromised,” he added.
