Strong immune system is the foundation of a profitable lactation

Inflammation

Dr McConochie says excessive inflammation, especially in the transition period, is the gateway to metabolic diseases.

While some inflammation is usual as cows repair and mobilise tissue, especially around calving, the problems start when inflammation becomes acute due to disease or stress.

Dr McConochie says: “When cows suffer inflammation, it is how they change the way they prioritise glucose that is important. Glucose is used in order for lactation, then growth, maintaining pregnancy, replenishing reserves and getting pregnant.

“It all works well until she suffers acute inflammation, then it all changes. Glucose is immediately and solely redirected to the immune system at a huge cost to milk yields.”

He explains a cow requires 100g of glucose to produce 1kg of milk, but an inflammatory response consumes 1kg of glucose every 12 hours, leading to 10kg of milk being lost over the same period, or 20kg/day.

Dr McConochie says: “Now consider that in most herds 10% of cows are experiencing a base level of inflammation due to high cell counts, lameness or dermatitis, and the cost becomes 200kg lost production per 100 cows per day.

“And this is before costs of treatments, elongated days open due to increased body condition loss and poorer fertility, and finally higher culling rates. Many diseases have a negative impact on days from calving to pregnancy as a direct consequence on the impact on inflammation on glucose use [see graph, below].

“You can see why strengthening the immune system and reducing inflammation should be a priority.”

It starts with transition

Matthew Pugh, director of Herefordshire-based Belmont Farm and Equine Vets, says ensuring cows have an effective, resilient immune system must be based on minimising stress.

He says cows in the run-up to calving, and in the first 30 days after calving, should be managed to maximise feed intakes and lying times within a high welfare environment.

Mr Pugh says: “Feed intakes are important because ketones which are produced by the cow in response to negative energy balance have been shown to impair immune function.

“The other issue is stress. Cortisol is a steroid hormone produced naturally around calving. Cows experiencing stress have higher circulating cortisol, which can suppress immune cell function. This is linked to poor immune response and impacts how the placenta detaches from the uterus and increases risk of cows retaining their placenta and, subsequently, increases risk of metritis.”

Effective

In addition to feeding adequate levels of minerals, Dr McConochie stresses the important of using the most effective and bioavailable source.

He says a good mineral is one supported by peer reviewed data, is stable in the rumen and gut and is absorbed effectively. He says only Zinpro Performance Minerals meet all these criteria.

He says: “Selenium, a powerful antioxidant is essential for an effective immune system. When dairy cows are stressed, toxins begin to accumulate in the body.

“These toxins damage tissues, affect normal metabolic function and more importantly suppress immune function.”

He explains that in times of stress, the demand for selenium can increase dramatically, so it is essential an adequate supply of selenium is provided on a daily basis for the production of antioxidants.

Availa®Se is efficiently absorbed and is the most effective at building up reserves of selenium in the tissues, he says. It is ready to be mobilised when cows are challenged by inflammation and need to fight oxidative stress.

“Reserves are particularly important as at time of high demand such as transition, intakes can be at their lowest. Only selenium which is absorbed in combination with an amino acid, such as methionine, will be incorporated and stored in body tissues.”

He says Zinpro Availa®Se is the only selenium source proven to be highly resistant to degradation in the rumen, meaning more is available for absorption.

It is absorbed almost entirely as Seleno-methionine and delivers 60% more Seleno-methionine to the tissues and colostrum than other sources of selenium yeast.

Dr McConochie says: “By being more efficiently absorbed and then retained as body reserves, Zinpro Availa®Se is the most effective way to ensure cows have the selenium they require to fight off infections.

Zinc

“In addition to selenium, Zinc is required for strengthening the epithelium, for controlling inflammation and promoting good liver function.

“Manganese and copper also play a crucial role in the immune system. The combination of Availa®Zn, Availa®Mn, Availa®Cu and Availa®Se provides the best nutritional support helping boost the immune system and ensure productive and healthy cows.”