Pillars of dairy success: Excelling in heifer rearing by starting fast and strong!

By Nicolas Anglade, Category Manager Ruminants, Hamlet Protein

Raising dairy heifers is often seen as a costly and labor-intensive process with delayed economic returns. However, modern dairy farming demands a shift in perspective: heifers are not expenses but investments that determine the future productivity, genetic progress, and profitability of the herd.

Keep reading to learn more about the science and economics of raising dairy heifers, focusing on the critical early phases. This includes early nutrition, weaning, and rumen development. You will be introduced to practical strategies to maximize returns.

The economic imperative: Why heifers matter

Dairy farmers traditionally prioritize lactating cows; however, heifers are the backbone of herd renewal and improvement. The Age at First Calving (AFC) is a strategic goal that marks the finish line for the dairy heifer and the starting line for the dairy cow. Once crossed, milk production gradually offsets the efforts made during the heifer-rearing phase.

A recent UK study of 101 dairy farms (Boulton, 2017) estimates the cost of each additional day of raising a heifer at €3.5 (2.87£). Reducing the age at first calving from 26 to 24 months can cut heifer rearing costs by nearly 18%!

As we say, time is money. Enabling the heifer to cross the finish line earlier ensures the farmer can get milk, and thus cash, more quickly and free up space in the herd. One day of milk production translates to a daily revenue of €12 to €20 (25 to 35 kg of milk sold at €0.52), compared to the previously estimated cost of €3.5 for raising the heifer each extra day.

These figures underscore the importance of an effective start!

The first few months: Establishing the growth curve

The foundation for success is laid very early. Calves must double their birth weight by 2 months to meet weaning readiness criteria. Heinrichs, in 2011, concluded the importance of rapid early growth for endometrium development and early puberty acquisition. Good starter feed intake from the start enhances lifetime milk production throughout the future cow's career. Conversely, a delay in the AFC penalizes milk production during the first lactation.

Soberon (2013) quantified the impact of a 100g improvement in average daily weight gain (ADG) at weaning by an additional 155 kg of milk during the first lactation. More recently, Bach (2021) evaluated an 100g ADG improvement at 70 days by an additional 108 kg of milk during the first 150 days of lactation and insisted on no delaying heifer growth to later phases, particularly during pregnancy.

The importance of protein nutrition

To accelerate heifer growth, a balanced diet that combines quantity, quality, and efficiency is essential. Rapid tissue development (muscles, organs, rumen structure) requires palatable, digestible, and healthy proteins. Frequent digestive issues in the early weeks, often due to incomplete intestinal and rumen functions, can hinder growth by limiting nutrient absorption and negatively impacting appetite and vitality.

Starter feed: A key role

Rumen activation is crucial in this initial transitioning phase: although calves start as "pre-ruminants," microbial fermentation in the rumen begins within weeks. Early intake of dry starter feed initiates biomass production and stimulates rumen papillae growth, preparing calves to transition from milk to solid feed.

Pre-weaning calf nutrition is biphasic. A decreasing portion of proteins is supplied by milk (or milk replacer), while an increasing portion comes from starter feed consumption. This progression ensures a smooth weaning and transition to the purely ruminant phase.

Often underestimated, starter feed is however crucial. It kickstarts the rumen and meets most nutritional needs during weaning and the following weeks.

Conventional starter feeds use standard ingredients like cereals, oilseed meals, and mineral salts. Soybean meal (SBM) is commonly used due to its abundance and nutritional profile. However, it contains anti-nutritional factors (ANFs) like oligosaccharides and trypsin inhibitors, making it a closely monitored ingredient in young monogastric diets. Less caution is taken with ruminants, as the rumen is thought to neutralize ANFs before intestinal passage.

Benefits of HP 300 in young ruminant nutrition

A recent study by the University of Illinois (Ansia et al. - 2021) found that in young ruminants, around the tenth week, approximately half of the protein from starter feed bypassed rumen fermentation, exposing the intestines to ANFs' adverse effects.

Using HP 300 from Hamlet Protein, which has undergone a bioconversion process to remove ANFs, in starter feed increased microbial proteins by 22%, reduced non-protein nitrogen transit to the intestine by 17%, and significantly improved ileal digestibility of amino acids from the ration by 15 points. Nine recent trials in reference farms and universities showed ADG improvements during the weaning-post weaning phase ranging from 35 to 220 g/day just with an average around 60-70 g by replacing conventional soybean meal (SBM) with HP 300 in the starter composition.

Turn challenges into opportunities by focusing on early protein nutrition

Heifer rearing is a high-stakes investment, but strategic nutrition and management can turn challenges into opportunities. By focusing on early protein nutrition, rumen development, and smooth weaning, farmers can raise heifers that calve earlier, produce more milk in their lifetime, and enhance herd profitability.

As the adage goes: "What's won at weaning is won for life."

Reach out to your local Hamlet Protein representative to learn more.

References

• Boulton, A. C., Rushton, J., & Wathes, D. C. (2017). An empirical analysis of the cost of rearing dairy heifers from birth to first calving and the time taken to repay these costs. Animal, 11(8), 1372-1380.
• Heinrichs, A. J., & Heinrichs, B. S. (2011). A prospective study of calf factors affecting first-lactation and lifetime milk production and age of cows when removed from the herd. Journal of Dairy science, 94(1), 336-341.
• Soberon, F., & Van Amburgh, M. E. (2013). Lactation Biology Symposium: The effect of nutrient intake from milk or milk replacer of preweaned dairy calves on lactation milk yield as adults: A meta-analysis of current data. Journal of Animal Science, 91(2), 706-712.
• Bach, A., Ahedo, J., & Kertz, A. (2021). Invited review: Advances in efficiency of growing dairy replacements. Applied Animal Science. 37(4), 404–417.
• Ansia, I., Stein, H. H., Brøkner, C., Hayes, C. A., & Drackley, J. K. (2021). Nutrient digestibility and endogenous protein losses in the foregut and small intestine of weaned dairy calves fed calf starters with conventional or enzyme-treated soybean meal. Journal of Dairy Science, 104(3), 2979-2995.