Scrutinising the crude fat, fibre and ash content in CMRs

Understanding and interpreting the label on a bag of calf milk replacer (CMR) is often confusing as when it comes to legal requirements, manufacturers need only declare the ingredients in descending order of inclusion.

Many omit to state if the product is detailed as freshweight or as dry matter (DM).

Due to rapid advances in nutrition in the past 50 years, it is accepted that the chemical analysis featured on milk powder labels is no longer the best indicator of quality. Labels are instead seen as a useful chronicle of how the feed was made.

But farmers are right to question if the way CMRs are labelled is fit for purpose.

Crude fat and oils

Fats and oils in milk powders are referenced as a single ingredient and can come from a range of sources, including palm oil, coconut oil, linseed oil, rapeseed oil and sunflower oil. The most common sources of fat in milk powders are palm and coconut.

It is a good idea to select a milk replacer with a range of fats derived from multiple sources as this creates a blend of short, medium, and long-chain fatty acids that support calf health and growth.

As an ingredient, buttermilk contains 4% milk fat, and this milk fat is the type that is the most digestible to the calf.

Critical to the animal being able to utilise fat is the correct emulsification of that fat with protein. Poorly emulsified fat-filled whey can create fatty lumps during mixing, leaving a greasy residue and biofilms on feeding utensils.

Fat inclusion on the selection criteria list is integral to calf performance, but bear in mind that inclusions do not increase energy levels significantly and need to be considered with dry feed to encourage rumen development, not stunt it. Research has shown that for every percentage increase in fat content, dry feed intake decreased by 11g a day1.

The recommended fat content ranges from 17% – 25% and the optimal amount of quality milk powder per head per day, 750g – 900g, depending on breed. Anything more will discourage concentrate feed consumption and subsequent rumen development2.

The consumption of fresh water, concentrate and forage causes bacterial fermentation in the rumen, produces volatile fatty acids, acetate, propionate and butyrate, and develops the papillae and musculature of the rumen wall, as well as supplying the animal with energy.

Crude fibre and ash

The fibre levels displayed on a milk powder label are not always indicative of vegetable protein content. Manufacturers can declare zero if the formulation contains less than 0.05% as the levels included in CMRs are below test accuracy. Reading the ingredients list is therefore recommended.

Ash levels are reflective of the mineral content within the milk powder, including calcium, phosphorus and sodium, and don’t necessarily dictate quality.

Skim milk powder is 8.5% ash, whey powder 11.5% and milk proteins that are poorer to digest, such as whey and permeate, 8.7%. An ash content of 6% – 9% is common.

Calcium, phosphorus and sodium are naturally present in a milk powder that has quality, low heat-treated ingredients. But if a label shows that any of these have been added, it should be treated with caution as it is no substitute for those that occur naturally.