The Role Of Digestion
“If cows transition well we see better milk production, reduced levels of disease and improved reproductive performance all of which are factors that positively impact longevity,” he comments. “And the role of digestion in helping achieve these is vital.
“One of the keys to good transition is understanding the way the cow has to adapt to changed conditions at calving. Helping her adapt will reduce the risk of events that can lead to cows not remaining in the herd.”
Mr Hall comments that transition is the most stressful time of the year for dairy cows. Having a calf, diet changes and group changes all bring about stressful situations for a cow to cope with. Giving the cow the tools to deal with these changes is key to ensuring transition success.
Changes In Dry Matter Intake
No matter how good the system in place on any farm, cows will always experience some form of stress over the transition period. This stress causes changes in dry matter intake which can have significant impact on how efficiently cows utilise the diet during this key period. “Any change in dry matter intake will bring about rapid re-modelling in the hindgut, which damages the lining of the small intestine”
The damage to the lining of the small intestine brings about leaky gut, allowing harmful endotoxins to enter the lumen. These endotoxins brings about an immune response and inflammation of the gut lining in the cow to try and fight off the effects of the harmful toxins.
“Once activated the immune response can only use glucose as a fuel source , which would normally be used for milk production or for processes to support fertility. An inflammatory response can use up to 1Kg of glucose in a 12-hour period, with 40 litres of milk requiring 3Kg of glucose.
“So inflammation will suppress milk yield, and as nutrients leak from the gut so the overall feed efficiency is reduced. Strategies to prevent the incidence of leaky gut, inflammation and changes in DMI will therefore help improve milk production.”
He advises that to prevent changes in dry matter intake farmers should pay careful attention to protocols around transition. Ensure plenty of feed barrier space, minimise group changes and group high stress/sick cows separately.
Selko Lactibute And The Role Of Butyrate
In addition, it will be beneficial to look at modifying fermentation at a hindgut level to reduce the impact of the inflammatory response. He explains that butyrate is one of the essential volatile fatty acids (VFAs) produced in rumen fermentation of feeds and increases the energy supply of the cow. It also has an important role in maintaining the integrity of the intestinal barrier and reducing inflammation, helping repair and minimise the effects of inflammation in the gut. By increasing butyrate production, it is possible to both reduce the incidence and consequences of leaky gut, meaning lower inflammatory response and more glucose available to the cow.
One way to increase the supply of butyrate in the small intestine is to feed Lactibute, a supplement containing calcium gluconate which promotes the conversion of lactic acid to butyrate,” Mr Hall continues. “This shift towards butyrate production specifically in the small intestines helps strengthen the gut barrier, reduce inflammation and reduce nutrient loss.
“In trials, this has been shown to increase milk yields by an additional 1.2 litres of milk per day. Lactibute can be added to compounds or the TMR and fed at 16g/cow/day.
“By maintaining a healthier gut, not only will you reduce the consequences of inflammation and ensure the diet is used more efficiently. You will also give the cow the tools to deal with stress more effectively.
“By reducing the impact of inflammation on the cow we make more glucose available to her on a daily basis. This glucose can then be used by the cow to bounce back in response to any insult or injury much quicker than she would normally do. Making the cow more resilient to stress is key to reducing cow losses and minimising drops in production.
As we move into the spring and summer Mr Hall emphasises that heat stress can have an impact on hindgut health and intakes. He says it is one of the primary causes of leaky gut, as it weakens the tight junctions in the gut lining. As these junctions are loosened, so the risk of leaky gut is increased.
The problem is made worse by the impact of reduced dry matter intakes, which are a common consequences of heat stress,
“Heat stress also reduces DMI as cows try to control their body temperature by reducing rumen fermentation which is a major source on internal heat. Reducing DMI brings about changes to the gut structure again and increases the prevalence of leaky gut..
“The drop in DMI combined with increased nutrient loss due to leaky gut are a major reason why heat stressed cows will transition less effectively.
“While I would urge farmers to take all steps to reduce the effects of heat stress on cows this spring and summer, it will also pay to maintain hindgut integrity so that even if DMI does reduce, nutrient capture will not be affected, and the supply of glucose will not be diverted from milk production towards fighting inflammation.”