Le Producteur de Lait Québécois MagazineVolume Number October 14, 2020
Débora SantschiPh.D., Agr.

PROFILab individual cow: a glimpse at what’s in the pipeline

PROFILab vache individuelle : un aperçu de ce qui se prépare

In collaboration with Daniel Warner, Innovation and Development, Lactanet

The fatty acid profile of bulk tank milk has been available to Quebec dairy producers since February 2020. Let’s take a look at what’s in the pipeline…

Tracking a herd’s fatty acid profile is a good way to monitor what’s happening in the barn. On the other hand, cows in a group or a herd each have their unique characteristics, and an individual cow indicator could be very useful in a number of situations. For example, we know that the stage of lactation has a major impact on the milk fatty acid profile. At the very beginning of lactation, nearly 50% of the fatty acids in milk are long-chain acids that come from the mobilisation of body fat reserves; these are the preformed fatty acids.

At the same time, the rumen and the mammary gland are still adapting to lactation, and de novo fatty acids (synthesized in the mammary gland) are not being used to the full. Mixed fatty acids, a combination of the two previous sources, generally follow de novo fatty acids in early lactation. Based on the data that we’ve collected in the past few weeks in Quebec, and consistent with what’s being seen in other parts of the world, most of the changes in the fatty acid profile seem to occur within the first 75 days of lactation, with the proportions stabilizing thereafter (Figure 6).

Figure 6: Milk fat composition is influenced by stage of lactation

It is clear that the changes in the different groups of fatty acids for cows in early lactation contain a great deal of valuable information, which can be used to ensure a successful transition and improve   performance in our herds. Here are some specific examples:

  1. Evaluate the mobilisation of body fat reserves

    Cows in early lactation have a negative energy balance and very often use the energy stored in their body fat reserves to meet the extremely high demand for nutrients required to produce milk. Although this is a natural and well-known phenomenon, it is often difficult to estimate the extent of the mobilisation. The milk fatty acid profile can be used for that purpose. Moreover, in combination with the analysis of ketone bodies in milk (including β-hydroxybutyrate [BHB] measured by Ketolab or blood tests), the milk fatty acid profile could provide greater insight into how cows manage this high demand for nutrients at the start of lactation, enabling producers to apply corrective measures to herd management and feeding during the transition period, as necessary.
  2. Estimate weight loss in cows

    As described in the section above, cows in early lactation mobilize body fat reserves, increasing the proportion of preformed fatty acids in the milk. By combining the composition of the different fatty acids and groups of fatty acids with other components such as total fat and BHB, it is possible to predict how much weight a cow will lose and respond appropriately to avoid excessive mobilisation that would diminish a cow’s reproductive performance and potentially reduce longevity in the herd.
  3. Assess the risk of ruminal acidosis

    Measuring something that isn’t visible to the naked eye, such as rumen pH for example, is definitely a way to use the milk fatty acid profile to benefit. This application is currently being validated through a joint project with researchers from Agrinova and Université Laval.  If it proves possible to accurately predict rumen pH with the fatty acid analysis, it will then be possible to use the profile to assess the risk of acidosis, and possibly prevent more serious consequences by optimizing transition management, particularly for cows in early lactation. 

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