Modern nutritionists clearly have a responsibility to help farmers produce milk and make replacement and calf rearing more sustainable.
But, according to Dr. Jessica Cooke from Volac, sustainability in agriculture goes hand in hand with efficiency – and the best calf nutritionists are now able to leverage this fact to improve the lifetime production potential and environmental credentials of heifers entering the milking herd.
“Maximising the efficiency of any dairy herd starts with the dairy calf. Calves have the greatest feed conversion efficiency potential early on in life, so nutritionists have always striven to take maximum advantage of this period,” she said.
“During the first two months of its life, a dairy heifer calf is able turn 100g of feed into 50g of growth. That’s a feed conversion efficiency of 2:1 or 50%. But as the animal ages, this diminishes steadily, so much so that by the time a calf is 15 months-of-age, 100g of feed will be delivering just 8g of growth.
“By not taking advantage of the high feed conversion efficiency potential early in life, heifers will have to grow more later in life (when feed conversion efficiency is low) to reach the same body weight at first calving.”
Dr. Cooke added that beyond the milk feeding period, it is also important to achieve growth rate target efficiently to avoid delaying the age at first calving.
“A heifer calving at 24 months-of-age will start to return a profit in the second lactation, whereas a heifer calving at 30 months will not return a profit until its third lactation.
“A delay in in age at first calving contributes to an overall reduction in the efficiency of a dairy herd due to lost potential milking days.”
However, she said that efficiency in calf rearing is also about getting ‘more from less’ or even ‘the same from less’.
Sustainable feed for calf rearing
“When it comes to providing the right pre-weaning nutrition in the current climate, we also need to consider the sustainability of our inputs – and the inputs of early life calf production are primarily concerned with the ingredients used in milk formulas.
“Sustainable sourcing of ingredients for milk powder formulations is becoming extremely important and, in this particular context, manufacturers have to consider both the impact of growing the ingredient and also the usefulness of that ingredient in meeting the nutrition requirements of the growing calf.”
When thinking about the dairy cow, one approach to improve sustainability is to maximise the quality and use of home-grown ingredients.
“Feeding the dairy calf gives rise to the opportunity to have an impact on lifetime performance potential and efficiency through the use of modern calf milk formulas. This represents a lifetime sustainability approach far greater than what can be achieved through feeding whole milk from the cow,” Dr. Cooke argued.
“However, when it comes to selecting calf milk formula ingredients, we need to understand how these have been produced; this involves issues such as land use, deforestation and social impacts on local communities – particularly when formulating ingredients sourced from overseas.
“We also need to evaluate yield per hectare, fertiliser and pesticide use and energy input requirements.”
Dr. Cooke said that palm oil, which is a key ingredient in many modern calf milk formulas, is often in the spotlight when it comes to sustainable sourcing.
“However, it is important to understand that there are sustainable options for palm, which offer support to smallholder communities, ensure best practice and education leading to no deforestation and no exploitation of local people.
“And, when you consider palm oil has a perfect fatty acid profile for efficiently meeting the nutritional requirements of the pre-weaned calf, simply omitting palm oil from milk formulations would be a misguided approach to addressing a much larger problem,” she stressed.
In fact, palm is the most efficient oil-producing crop available today – producing more metric tonnes of oil/hectare than any other vegetable crop.
“Indeed, producing palm is particularly attractive for local smallholders because it can be grown on a variety of soils, requires relatively little fertiliser or pesticide and bears its fruit all year round.
“Currently, oil palm is grown on approximately 7.49% of land devoted to vegetable oil crops, yet palm oil makes up 41.1% of all vegetable oil production,” said Dr. Cooke.
Efficient use of by-products
Thanks to the efficient microbial population in a fully developed rumen, adult dairy cows have always been able to make use of a variety of by-products from other industries. This clearly helps with the sustainability goal.
But, uniquely, Volac is exploiting this same trend for calves too – by supercharging whey, a widely available by-product associated with cheese manufacturing.
“What you can certainly be sure about is the focus Volac nutritionists constantly have on sourcing the best ingredients for modern calf milk formulations – and particularly those ingredients that we know will deliver the best balance between animal performance efficiency and sustainability,” Dr. Cooke concluded.
For more information on Volac’s sustainable feed for calf rearing, click here.
