Immune suppression can leave cows vulnerable to infection

During The Vital 90 Days - the period between drying off and one month after calving - nearly all dairy cows suffer from an impaired immune system. Around calving, number and activity of neutrophils - white blood cells that are the first line of defence against infections - are reduced by up to 40%. This leaves fresh cows  more vulnerable to common transition diseases like mastitis2, metritis3, and retained plancenta4.

[+] What causes immune suppression?

· Stress impacts the cow's immune system, which becomes less effective in fighting disease. Conditions such as high stocking density, group and pen changes, limited access to food and water can cause stress. 

· Nutritional status. Fresh cows are at a particular risk of a negative energy balance, high ketone and low calcium levels - which all impact the cow's immune system

The negative energy balance, measured by high levels of ketones and non-esterified fatty acids (NEFA), impacts neutrophil function by reducing its migration to the site of infection

Cows with low calcium levels (milk fever) are more prone to infectious diseases, as calcium plays a critical role in immune cell activation and migration to the site of infection.

[+] Measuring immune related diseases & reducing the risk of stressors

There are multiple ways to mitigate the impact of immune suppression. Some decisions are short term and require time investment or a new organization, other are longer term and may need financial investment. Either way, they rely on data and risk analysis. 

STEP 1: MONITORING DISEASES

The value of disease monitoring is to identify problems early on and act on them. The consistent detection and recording is the key to making better, more impactful management decisions for the individual cow, the herd, and the entire dairy farm.

Using a simple tool such as a transition cow wall management planner to record mastitis, metritis and retained placenta provides information on the impact of immune suppression in your farm.

If you want to go digital and also record additional parameters, (ketones, non-esterified fatty acids,) the Keto-Track App will be your tool to record and visualize status of the herd. 

STEP 2: IDENTIFY THE RISK FACTORS

A structured science-based farm tour will help to evaluate risk factors and stressors, prioritize and decide on corrective actions. 

Ask your vet about the Healthy Start Checklist, a simple scorecard to help assess risks on your farm. 

You can also go through this audit with your vet using the digital Risk Assessment Tool, an app focusing on the transition period (from far off dry cows to fresh cows)

STEP 3: ADDRESS IT

Tools like these can identify risk factors and indicate the need of intervention regarding farm management, preventive health programmes and feeding.

Examples:

· Feeding management. Best practices include easy access to drinking water and to high quality feed adapted to the needs of the transition cow. Consider adding feed supplements such as trace elements (e.g. vitamin E, selenium) to support the cow's immune function.

· Reduce stress. Consider creating a specific, quiet and clean calving pen. Take a critical look at group and pen changes, stocking density, ventilation, bedding quality, heat stress, and access to feed and water.

· Preventive health management. Regular hoof trimming, footbaths, hygiene measures mastitis control programmes, will help reduce disease incidence and the spread of harmful pathogens. Deworming and vaccination will help prevent diseases (e.g. respiratory, reproductive & digestive).

PREVENTION IS KEY

Preventive management measures will help improve the cow's immune function and energy balance, decreasing the risk of disease, giving you peace of mind.

Supporting the immune function and the energy balance are essential parts of dairy cow management during the Vital 90 Days. Ask your vet to monitor disease and evaluate risks.

Ask your vet how to monitor disease indicators and to identify risk factors and stressors that may lead to immune suppression. 

 

[+] References

Kimura K, Goff JP, Kehrli ME, Decreased neutrophil function as a cause of retained placenta in dairy cattle. Journal Dairy Science 2002; 85 (3): 544-550.

Hammon DS, et al, Neutrophil, function and energy status in Holstein cows with uterine health disorders. Veterinary immunology and immunopathology 2006; 113: 21-29.

Sordillo LM, Factors affecting mammary gland immunity and mastitis susceptibility. Livestock Production Science2005; 98: 89-99