Milk solids are more expensive than starter feeds so it's not unreasonable to assume that feeding more milk solids will cost more. However, Professor Àlex Bach, Research Professor ICREA and IRTA in Spain, explained why it can be more cost effective to feed calves more early in life.
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Feed conversion efficiency is much higher during the first weeks of life than at any other point in the growth cycle.
So every kilo you feed in the first two months of life will cost you less than doing so later in the cow's life. That's why it is beneficial to set high growth targets in the first eight weeks of life.
Economic analysis shows that feeding more in early life produces a more cost efficient cow in the longer term, largely due to the link between improved growth and associated benefits for reproductive and lactation performance.
Early growth can boost performance
Meta-analysis of a multitude of studies demonstrates a clear relationship between calf growth and milk production. Professor Bach described that for every 100g of average daily gain (ADG) in first two months of life, you can expect approximately 250kg of extra milk in first lactation. A heifer that matures faster can be bred earlier, improving her reproductive performance too. There may also be longevity benefits; if cows produce more milk and are more resilient to disease, they are likely to stay in the herd longer and reduce your cull rate.
Professor Bach believes there are two key factors holding us back from improving our dairy production: 1) lack of attention to heifer rearing; and 2) inadequate early life nutrition. The latter is being maintained by the false belief that increasing the amount of feed early on costs more, which is a misconception we need to challenge. He suggested that instead of focusing on how much is being spent on feed pre-weaning, we should evaluate overall costs of raising a heifer in the context of her lifetime performance.