Expert interview: Feeding dairy cows in 2023 and beyond

Trevor DeVries, professor at the University of Guelph (Canada)

Feeding cows is all about feeding the rumen. But what defines a healthy rumen?

A healthy rumen is one that allows the cow to maintain a high level of dry matter intake and, at the same time, ensures the microbial population is stable, translating into efficient digestion of ingested feed. In dairy cow nutrition, we want to prevent having large swings in acid accumulation in the rumen because a low pH has a negative effect on rumen microbes and rumen wall integrity, leading to things like milk fat depression and reduced digestion efficiency. Because of the high milk production in today’s dairy cows, we cannot prevent all situations of negative energy balance and rumen health challenges, but the art is to not pass the tipping point where the rumen conditions may lead to other health issues. We are constantly challenging the cow and her rumen, so we have to treat it well.

An unhealthy rumen will lead to inconsistent feed intake, microbial changes, poorer efficiency, etc. Then it becomes a vicious cycle. It is all about the balance. Besides what diet cows are provided, we also know that feeding behavior has an effect on rumen function and health and is, thus, important to consider.

Can you explain why feeding behavior is important?

There is much variation between cows, as a result of behavioral individuality or personality of individual cows. We see differences in how they behave in a group and their level of boldness or shyness, for example. These individual differences are reflected in how cows use a milking robot, for example, or how often and how much they eat. We know that feeding behavior is inheritably linked with dry matter intake (DMI), which, in turn, directly impacts milk production. So, if we want to increase the DMI, we have to look at the feeding behavior of the cow, such as the timing of meals and meal size. If we can better manage this, we improve production. We have demonstrated in our research that greater DMI is associated most consistently with more time eating per day and having more frequent meals per day. Interestingly, those feeding behavior patterns are also more conducive to a stable and consistent rumen environment.

We also should not forget how the cow behaves after she has finished each meal. It is important that cows have the time and space to comfortably lie down and ruminate. Rumination, particularly that which occurs while cows are lying down, is also associated with greater DMI in cows. Small adjustments in feeding behavior through diets, housing and management can make a big impact, and we are learning more on this every day.

Professor Trevor DeVries was one of the speakers at the technical event ‘Feeding dairy cows in 2022, the latest updates: welfare and precision feeding – From left to right: Nicolaas Vreeburg, DVM, Lallemand Animal Nutrition, Trevor DeVries, Bertjan Westerlaan, DVM, Vetvice, Netherlands, and Laurent Dussert, Global Category Manager, Lallemand Animal Nutrition

Are we doing a great job in applying precision feeding to dairy cows?

Precision feeding is all about getting the right nutrients to the right animals at the right time. And this still can be a challenge in dairy cows. The ideal scenario is to feed each individual cow a tailor-made diet that perfectly fits her nutritional needs. To a certain extent, we can do this by supplementing feed individually (e.g. in a milking robot) and/or by making groups according to the stage of lactation and milk production levels. This way, we prevent under- or overfeeding cows, and can be more cost and feed efficient.

Feeding specific groups is already a great step forward in precision feeding and a more common practice on large dairies. Feeding each individual cow a different and specific diet has its challenges in practice. I see great potential in the use of technology/sensors to improve precision feeding of dairy cows. Measuring eating time and rumination time in cows gives us more data and awareness about the role of feeding behavior and allows us to adjust diets, but also feeding management, or critically look at stocking densities for example. Getting a better grip on dietary and non-dietary factors is a big part of what precision nutrition of dairy cows is all about.

Certain feed additives are also a crucial part of the precision nutrition approach, especially when targeted to the right animals at the right time. In dairy cows, feed additives — such as yeast supplements — may help stabilize rumen function, increase rumination and increase milk fat percentage among other things.

In the coming years, I see the art of precision feeding of dairy cows further developing and growing. It is an exciting area to work in.

 

Professor Trevor DeVries was one of the speakers at the technical event ‘Feeding dairy cows in 2022, the latest updates: welfare and precision feeding,’ which was organized by Lallemand Animal Nutrition on November 9-10 in Wageningen, the Netherlands.