Article Summary:

Supplements are a great farm management tool with the potential of increasing milk production during the late lactation period. Adding supplements substitutes pasture intake. The level of substitution depends on factors such as season, post-grazing targets, type of pasture grown, supplements offered, and animal factors like BCS. Learn with us how to maximize farm profitability with supplements.

A general rule of thumb is to add supplements to the cow's feed when there is not enough pasture available for grazing. This will support your farm business into the future.

There are no qualms that high-quality pasture makes the cheapest and most profitable feed. However, the addition of supplements will fulfil cows' need for nutrition, as a result, there will be more pasture in the paddocks. Supplements are also used in wet conditions when grazing pasture damages the soil. There are various incentives to using supplements in the feed. For once, using supplements yields greater milk production in late lactation periods.

When supplementary feed is added to the pasture-based system, the substitution determines the milk yield. How financially viable supplements would prove to be, depends upon the milk yield and the cost of feeding supplements.

In this article, we explore how supplements increase milk production in the late lactation period. Farm management can use supplements to achieve growth targets by measuring the cost of using supplements. Afterwards, we will answer some frequently asked questions about supplements and substitution. Let’s get started already.

How do Supplements affect milk yield?

In ideal conditions, adding supplements returns approximately 70-80g Milk Solid/kg DM. However, the average response to supplements at commercial scale is around 55g Milk Solid/kg DM. This indicates that adding supplements alongside feeding pasture has the potential to increase production as compared to feeding non-supplement feed. However, there are various factors that affect milk yield. These are:

  • Supplement offered and wasted in the process
  • Supplements eaten
  • Increase in net feed intake by the cow
  • The yield of additional milk in response to supplements
  • Pasture that was spared
  • Wasted supplements and pasture

Using Supplements

Let me stress that again, in pasture-based systems, supplementary feed ought to be used when there is a feed or energy deficit. Supplements can be used:

  • When there is more feed demand than pasture can fulfil.
  • When pasture management deems it necessary to meet the post-grazing targets.
  • In times when pasture growth is slower as a result of either climate conditions or other factors, the addition of supplements can equate to the pasture demand.
  • Supplements make a good choice for heat-stressed cows who consume less DM.

Measuring the Cost of adding supplements

As stated earlier, adding supplements depends on the farm management growth targets. If the purpose is to fill feed or energy deficit, their cost per MJ of metabolizable energy should be considered. The quality of supplements ought to be the prime factor before making a purchase.

Furthermore, supplements should be easy to feed so as to minimize wastage or spoiling. That being said, proper infrastructure will make a huge difference when it comes to avoiding feed loss.

Feed wastage also depends on the feeding method and management practices. Farm management will benefit from offering varying quantities of supplements to minimize wastage while fulfilling the nutrient requirement.

Percentage supplement Infrastructure Used
5% In- shed
10% Feed pad
15% trailers
20% Paddocks in dry conditions
40% Paddocks in wet conditions

What does it mean by Substitution?

Milk yield increases when pasture intake is reduced by the addition of supplements. The feed substituted by the supplements is named substitution.

Take Away: For every 1kg DM of supplementary feed consumed by the cow, its grazing time will be reduced by 12 minutes.

Every time cow consumes supplementary feed, there is some substitution. As a result, there will be less intake of dry matter.

FAQs about Supplements and Substitution

How many supplements I can feed in pasture surplus times?

If the available pasture is 1500-1600kg DM/ha, then it’s more profitable to feed pasture. Feeding pasture is cheaper and more profitable. However, if certain conditions or farm management targets are to be achieved, then feeding supplements by considering overall revenue would yield good results.

For instance, feeding supplements in the late lactation period would increase the milk yield.

What are the factors that affect substitution?

  • Substitution increases the average nutrient intake and thus increases productivity. Substitution can be positive or negative.
  • Positive substitution: Pasture is consumed less and thus spared.
  • Negative substitution: Pasture is wasted.

The rate of substitution depends on the following factors.

  • Season (more in summer, rainfall, or winters)
  • Post-grazing targets
  • Type of pasture (grass vs. clover)
  • Type of supplement added to the feed
  • Animals and growth goals

Does time of year affect substitution?

Yes, time of the year also affects substitution. It is observed to be greatest in the spring and lowest in the autumn.

Substitution is greater in spring than it is in summer and greater in summer as compared to autumn. For instance, 1 kg of supplement eaten would reduce pasture intake by 0.4 kg DM in summer.

Season Reduction in pasture intake for 1 kg of supplement consumed
Spring 0.5 kg DM
Summer 0.4 kg DM
Autumn 0.3 kg DM

Would type of pasture affect substitution?

Yes, the type of pasture cows feeds on also affects substitution.

It is observed that in the case of grass dominant pasture, there was a greater level of substitution. In the case where cows were feeding on white-clover pastures, substitution was less.

It is observed that substitution depends on the digestibility of pasture species. In pastures offering the same species, there was more substitution rate when pasture offered greater digestibility.

How does feeding different supplements affect the level of substitution?

The level of substitution also depends on the type of supplement offered. For every kg DM of supplement, grazing time is reduced by 10-12 minutes. However, there is 10% more substitution when forage (maize silage) is offered as a supplement as compared to when concentrate (maize grain) is offered.

Although the results are not consistent, some researchers observed differences in substitution levels when concentrates were fed.

  • Concentrates with starch as the main supplement resulted in greater substitution as compared to fibre-based concentrates.
  • Highly digestible concentrates such as cereal grains result in a greater substitution level as compared to whole grain concentrates.

Careful when feeding high amounts of sugars and starches as they may lead to acidosis and ultimately decrease the feed intake.

Does animal factor affect substitution?

Yes, animal factors affect the rate of substitution. These are;

  • Body condition score that indicates the energy state an animal possesses.
  • Breeding indicates genetics.

For example, under some conditions, a cow with lower BCS will substitute less pasture as compared to a cow with greater BCS.

In conclusion, the use of supplements depends on the farm growth targets, seasonal constraints, pasture type, and farm business goals.

This brings us to the end of this article- until we meet again, Happy Grazing!

- The Dedicated Team of, 2022-03-11