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Tips for optimizing fat production and your milk cheque

Andrée Bourgeois for Progressive Dairy Published on 30 August 2019

Did you know 58% of your income is directly related to the amount of fat delivered? And an even larger proportion of your gross profits are linked to it?

The fat present in milk is influenced by five main factors: management and genetic selection, animal factors, environment, diet and intestinal health.



Therefore, you can act on certain management and feeding aspects which benefit your income in the short term. Here are some tips to help you:

1. Focus first on the health of the rumen: Rumination contributes to the production of substances such as acetic acid, which favours milkfat. It has been shown that increased rumination time up to a maximum of 500 minutes per day improves fat test.

The space at the manger and the fibres, in particular, are examples of elements likely to optimize rumination. Note that feeding forages before concentrates helps to create a fibre mat in the rumen and promotes acetate production.

In TMRs, on the other hand, having too many long particles increases sorting and causes a decrease in the fat content in the milk.

Too fine a ration is not desirable either. Ask your feed company representative to sift it with a Penn State particle separator: At least 50 percent of the sample should be in the middle sieve.


2. Serve the ration in two meals rather than one: In a controlled study, this allowed the same total quantity fed to increase milk yield per cow by 2 kilograms per day.

At 4% fat and 100 cows, that’s 2,920 kilograms of fat gained over a year. Also, remember to push up the ration as often as possible.

Ensuring unlimited access to the feeder, especially after milking (at least 24 inches of space at the feeder and ration at will) will have the added benefit of promoting calm and harmony in the herd.

In individual feeding, serving several small meals of concentrates up to 4 kilograms also contributes to a healthy ruminal pH.

3. Make more milk. To make more kilograms of fat, the equation is simple: Make more milk.

In recent years, we have calculated income over feed costs on 931 farms. In these farms, 78 percent of the margin is due to fat production in kilograms per cow per day (Figure 1).


Kilograms of fat per cow per day vs. income over feed costs

4. Provide water on a daily basis: To make milk, it takes water. In loose housing, a minimum of 4 linear inches of watering trough is required. In tiestalls, a minimum flow of 20 litres per minute is required at all times.

5. Monitor equipment: Milk that has frozen or has been overagitated in the tank may show up as a drop in the fat test.

6. Minimize heat stress: The heat we can experience is painful for cows. Inevitably, their consumption decreases, thus immediately affecting the production of milk and components.

We have observed in our monthly compilations of peaks of lactation that the negative impact is observable for months after heat stress (Figure 2).

Effect of heat stress on peak lactation  for multiparous cows

7. Avoid energy deficits: No energy, no fat … it must be remembered that 50 percent of milk fatty acids are synthesized in the mammary gland, and the rest comes from the diet.

It is also recognized that equilibrating amino acids (e.g., methionine) can bring more fat into the milk.

Specific nutrients such as magnesium oxide, potassium, sodium bicarbonate, yeasts, vitamins, rumen modifiers and protected or free fats are all ingredients that need special attention given their influence on the test.

It is your representative’s job to ensure your ration is refined to the smallest of nutrients and amino acids.

8. Watch the growth of heifers: It has been shown that for every kilogram of pre-weaning gain of calves, the future cow will produce 1,500 kilograms of milk more at first lactation.

For a herd of 100 cows, this can be 2,057 kilograms of extra fat per year. To do this, it is recommended to feed young calves three times a day and to wean them gradually.

9. Promote gut health: Ruminal health has been a focus for many years, but new research is now showing the importance of a healthy gut for fat production.

The micro-organisms that live in the intestines, and the rumen in particular, are collectively called the microbiome.

In both cows and humans, the microbiome is a major contributor to the health and productivity of the animal. This population of micro-organisms works like an army of little soldiers in the digestive system, which could be compared to the Great Wall of China.

The tissues of the digestive system serve as a defense barrier with a complex network of gates (such as the wall), which allow the removal of waste, nutrients or sometimes pathogens. If necessary, the animal’s defense mechanisms must be mobilized to cope with the threat, further reducing the available energy for the animal.

This is the same principle as when a herd is vaccinated: The immune system is on alert, and we often observe a decline in milk production immediately after vaccination.

New research on the gut microbiome is showing interesting breakthroughs in favour of optimal efficiency in dairy cows.

Management and dietary efforts can help you improve your herd’s fat production and, ultimately, your income.  end mark

Andrée Bourgeois
  • Andrée Bourgeois

  • Technical Service Manager
  • Shur-Gain East/Trouw Nutrition
  • Email Andrée Bourgeois