Pre-weaning is a critical time for influencing the lifetime performance and wellbeing of a dairy calf. Enhancing early development improves survival, growth rates, and higher performance in future lactation and reproduction, while also reducing disease susceptibility and veterinary costs1-5.
Studies indicate scientists and farmers are underestimating the value of the pre-weaning period and missing out on the animal's full potential by not feeding accordingly.
Starting right
Raising a strong, healthy calf begins with good nutrition and health management of the cow during pregnancy. After birth, an immediate and sufficient intake of quality colostrum post birth is essential for successful calf rearing. Colostrum provides a nutrient-dense feed and non-nutritional factors to support the development of the calf’s immature immune system, also known as passive transfer, and the digestive system. This prepares the calf to digest and absorb nutrients provided in colostrum and milk and assists in keeping the newborn warm, and protecting against common diseases such as scours.
Colostrum management is challenging on-farm, especially in seasonal dairy systems like New Zealand. Some 33 percent5 of farmers report a failure of passive transfer. AgResearch has shown feeding newborn dairy calves with high-quality colostrum versus low-quality (Brix ~23 vs. 12) improves passive transfer of immunity, reduces scours incidence by three times, improves growth rates (+100 g/d), and enhances intestinal development and feed conversion efficiency7.
Author: Dr. Sue McCoard, Senior Scientist, Sustainable AgriSystems - Grasslands, AgResearch Group - Bioeconomy Science Institute, New Zealand
The benefits of a higher milk allowance
The next stage is ensuring calves receive enough milk or Calf Milk Replacer (CMR) to maintain health and grow well. Milk or CMR is the primary nutrition source of calves in their first three to five weeks of life. As the rumen develops, additional nutrients are provided through solid feeds like concentrates and forages. This period is your golden opportunity to maximise growth when feed conversion efficiency is high. Liquid milk is more nutritious and easier to digest than concentrates and forages.
Research shows higher milk intake pre-weaning— eight litres of whole milk instead of four litres—is more beneficial to the calf’s growth rate and metabolic and immune function and does not affect solid feed intake2. However, milk intakes above nine litres a day can reduce solid feed intake and rumen development3.
Investing in the future
Research demonstrates improving future milk production is directly linked to better pre-weaning growth— for example ~800 g per day vs 500 g per day.4,5
Higher pre-weaning growths are also associated with improved conception rates and reduces culling rates in dairy cows1. A recent meta-analysis suggests greater lifetime productivity is supported targeting a milk/milk replacer feeding level of greater than 800 g of dry matter per day4.
Collectively, these examples from research trials highlight the benefits of investing in pre-weaning calf nutrition and management to support both short and long-term performance and wellbeing of the herd.
