How Maximising Litres Can Affect Gut Health

By Anna Millar, Ruminant Technical Manager, Trident MicroNutri

With the current favourable milk to feed price ratio, it seems there is no better time to feed cows well. It’s good to maximise litres produced at a better milk price, with lower feed costs. As this is the time of year many herds are tending towards peak yield, it is important to support the cow’s energy demands by feeding concentrate, making the most of forage supplies and improving feed efficiency.

While it is a good idea to feed more concentrate to meet energy demands, we must be aware of the effects of this on the rumen and overall gut health. The most obvious effect is acidosis, and this occurs when there is an accumulation of acid in the rumen due to the rapid digestion of concentrates. This causes the overall pH of the rumen to fall, or become more acidic, which has detrimental effects on the balance of microbial digesters in the rumen. Common signs of acidosis are decreasing milk butterfat, loose faeces, dropping cud-balls, increased rate of lameness and lower body condition score. While these signs are visible to the eye, there are two other main effects occurring below the surface – inside the gut itself.

The gut wall is made up of rows and layers of cells which help regulate what the cow absorbs from the gut contents into the blood. The gut wall allows absorption of nutrients into the blood, while preventing the uptake of undesirable bacteria or toxins. When either the rumen or the hindgut becomes more acidic, the integrity of the gut wall is compromised and the junctions between cells become faulty (move further apart), allowing more space for bacteria and toxins to be absorbed. This is known as ‘leaky gut’ and is shown in Figure 1. When bacteria or toxins are absorbed into the blood, this initiates an immune response. Research has shown that for a Holstein dairy cow, the energy requirement to fuel an active immune response is around 2kg glucose per day. This equates to a cost of 7kg of milk (Kvidera et al., 2017). Therefore, there is significant cost associated with leaky gut due to acidosis.

The other main effect of acidosis on gut health concerns the gut bacteria. In acidic conditions, some bacteria burst (gram-negative bacteria) and release endotoxins. These are different to the mycotoxins we commonly find in feeds. Endotoxins are detrimental to cow health as they pass into the blood stream (especially when the gut is leaky) and induce an inflammatory response, again costing the cow energy which she could have used otherwise for milk production.

To help support cows during periods of high concentrate feeding and to minimise the effects of excess acid, a combination approach is recommended. AcidBuf can be fed to help balance acid and reduce the likelihood of decreasing pH in the gut. This in turn reduces the risk of leaky gut and the release of endotoxins. Ultrasorb can be fed alongside this to help bind endotoxins, preventing them from being absorbed into the blood, and reducing the likelihood of an inflammatory response, which costs energy.

In summary, now is a good time to consider feeding more concentrate to make the most of the good milk to feed price ratio, especially if your milk contract is volume-based. However, do so carefully and remember the effects on gut health and overall productivity due to the energy cost of inflammation. For more information on how to maximise litres while maintaining gut health, or how AcidBuf and Ultrasorb can be of benefit, please contact us on 02894 473478 or complete the contact form and we will get back to you!