Productivity and the immune response

Have you ever walked through a maze or played a maze game? These days, farming is something like being in a maze, with many twists and turns and walls that seem to rise in front of us as challenges to the end goal of efficient production. One of the challenges that we are faced with in farming is the weather. Weather events are becoming more extreme; winter arrives later and is shorter, and the wet seasons are crazy – that is, if you are lucky enough to actually get some rain. This all adds to stress, which poses greater additional challenges to immunity and, ultimately, production. We need to find means to face up to the challenges without negatively affecting our returns, but rather find the twists and turns in the maze that that will take us on our way to greater economic returns.

Some of these challenges are not within our control. What we can change, however, is the manner and efficiency with which our animals respond by enabling them to mount a rapid, effective immune response. This is important because we are in the efficiency business, where input versus output matters immensely in delivering an economic return. These returns are reflected by fertility (age at first mating, days to first insemination, conception rate), production (milk yield and composition), and health (somatic cell count, colostrum quality).

Building stronger barriers and enabling a rapid and effective immune response involve three major role players: nutrition, vaccination, and management.

Nutrition

Feed can often be viewed superficially and one-dimensionally simply as sustenance, while the role of preventative nutrition is ignored. Preventative nutrition involves keeping animals in an adequate nutritional status or physical condition so that their immune system can function effectively when needed. For this reason, it is important that all animals on the farm (calves, heifers, pregnant cows, and cows in milk) should be provided with a specific, well-balanced ration in order to supply the correct nutrients for optimum immune functioning.

Energy provides fuel for immune cells and protein serves as the structural components for cells and antibodies. This implies that inadequate energy and/or protein may impair the immune system and its effectiveness. The role of optimum mineral nutrition is sometimes overlooked, yet it plays an integral part in the forming of a strong, healthy first line of defence (epithelial skin and hooves) and in the functioning of the immune system, among its other functions. There are five minerals that are specifically important for the immune system and should be supplemented to meet the cow’s requirements: zinc, chromium, copper, manganese, and selenium. Research shows that the threat of disease and immune suppression are greatest at calving, which is why it is imperative to maintain optimum cow health over the dry period. It is important to note that a substantial amount of energy and other nutrients is diverted away from production, which includes growth, reproduction, feed efficiency, and milk production, when an animal’s immune system is challenged.

Immunisation

Proper planning prepares you mentally for possible twists and turns in the path, including by teaching you to be resilient, and it sets you a few steps closer to your goals. Vaccination prepares the animals for improved resiliency and resistance to infectious diseases. Just as you would plan and work together with your team before entering a maze, it is important to plan your vaccination programme, working closely with the local veterinarian.

It is important to follow instructions on timing, dosage, handling, and administration of vaccines in order to achieve an effective immune response. These instructions include avoiding exposure of the vaccine to heat and direct sunlight, using clean syringes, and adhering to the recommended method of administration. The effectiveness of the immune response will also depend on the nutritional status of the animal.

Management

Management on-farm can influence an animal’s immune system through stress and colostrum management. Getting lost in a maze is stressful and draining. Similarly, stressful situations can also have negative effects on the immune system. Common stressors include:

•           calving;

•           the route to the milking parlour;

•           handling during milking;

•           insects (flies);

•           changes in feed and/or water quality or quantity;

•           wet and muddy conditions; and

•           heat stress.

The 3 Q’s of colostrum are quality, quantity, and quickly. On many farms, colostrum quality is not tested, and calves may be given too little, too late. The calf’s ability to absorb immunoglobulins is highest in the first two hours after birth and decreases rapidly after six hours. After 24 hours, the ability to absorb immunoglobulins ceases and the chances of survival are reduced, as is the ability of the heifer calf to express her full potential productivity due to the compromised development of the immune system. Therefore, colostrum must be tested, and good-quality colostrum must be stored (frozen) for seasons of greater immune challenges and fed to newborn calves as soon as possible.

Conclusion

Every maze has a start and a finish, regardless of the number of twists and turns on the path. How we prepare ourselves will determine which turns we decide to take. Dairy cows should be enabled to mount a rapid and effective immune response through optimal nutritional management, a well-planned immunisation programme, and the improvement of on-farm management. All our animals are faced with different threats to productivity and they need to be immunised and equipped to mount a rapid, effective immune response. This can be achieved by applying preventative nutrition, following a well-planned vaccination programme, and improving management on our farms.

Cleopas Tlotlang Lephallo

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Cleopas Lephallo is a ruminant technical adviser at Chemuniqué

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