Julie Baillargeon_1
Le Producteur de Lait Québécois MagazineVolume Number December, 2019December 10, 2019
Julie BaillargeonM.Sc, Agr.

The story of Buddha: a stressful life

L’histoire de Bouddha, une vie de stress

This article was written in collaboration with Diane Lequin.

There is more stress in a cow’s life than one might imagine. As is the case for humans, stress can be useful in some situations. It’s when there is too much of it, too often or for too long that the consequences have an adverse effect on animal health and productivity. Through the story of Buddha, a cow that is not as Zen as her name might suggest, we’ll examine the stressors that arise in the life of a cow.

With a name like Buddha, this calf seems destined for a stress-free life. Not so, however, as Buddha has already been exposed to the effects of the stress experienced by her dam before she was even born. Last year, one hot day followed another while her dam was drying off, and the ventilation system in the barn where dry cows are housed at Temple Farm is inadequate to mitigate the effects of extreme heat. The aftereffects of that heat stress will last a lifetime.

Buddha is born four days early, at a low birth weight of 5 kg, a deficit that will persist until puberty. When it’s Buddha’s turn to give birth to a calf, she will produce 5 kg of milk per day less than her congeners whose dams were not exposed to extreme heat during dry-off. What the producer doesn’t know is that the stress experienced by Buddha’s dam during the first weeks of pregnancy has permanently altered her calf’s genes.

A lot of stress for a little calf

Although chains weren’t required to extract Buddha from her warm and cozy nest, birth itself is an unsettling event. Despite the fact that she promptly receives colostrum freshly milked from her dam, Buddha is less able to absorb antibodies than are her companions whose dams did not suffer from thermal stress during the dry-off period. As a result, her natural immunity is weakened. Buddha is quickly transferred to the small pen where she will be housed alone until she is weaned.

Some 10 days later, Buddha suffers from an episode of diarrhea, becomes dehydrated and requires veterinary attention. In the weeks that follow, Buddha gets all the care she needs, including vaccines and dehorning, and then it’s time for weaning. Buddha is now housed in a larger pen with older congeners, which means she is exposed to a host of new microbes against which she is not yet fully equipped to defend herself. All these disruptions lead to a state of physiological stress, causing inflammation and hindering her intestinal development. This may have a lifelong impact on the health of her immune system and her susceptibility to disease.

Lactation: a period of major adjustment

Like the neonatal period, the first weeks of lactation are among the most stressful in Buddha’s lifetime. To begin with, she has to adapt to a new environment and new habits (handling for milking, a new ration, etc.).  Simultaneously, her body is going through abrupt hormonal changes that will enable her to produce large quantities of milk. The transition period is crucial in preparing for that upheaval. Will Buddha’s owner be able to provide her with better living conditions than her dam enjoyed?

After calving, Buddha seems to be doing well, but a routine BHB test reveals subclinical ketosis. This is not surprising since more than 50 per cent of cows suffer from a metabolic disorder in early lactation. The early culling that results has a significant impact on herd productivity. Despite all the efforts made to minimize the incidence of health issues in early lactation, the problem remains significant. What if the answer lies in managing stress and inflammation?  

All cows experience some level of systemic inflammation in the first few days after calving. The inflammatory state plays an important role – for example, in initiating calving, producing contractions and expelling the placenta– but when prolonged, it is also associated with a higher risk of disease, reduced feed intake and lower milk production over the whole lactation.   

In spite of her outstanding genetics, an impeccable ration and a comfortable environment, Buddha’s milk production proves disappointing. And, as if this wasn’t enough, mastitis is added to the mix! Buddha’s owner is slowly realizing that she is costing him much more than she brings in.

Stress: a new avenue to explore

Who would suspect that a series of stressors of varying importance could lead to fragile health and so-so production? Nonetheless, research findings over the past few years are steering us in that direction. It is an interesting avenue to explore to enable cows to reach their full potential. So where do we start? We don’t yet have the means to measure stress directly, but we do have access to other tools, such as the Transition Cow Index®, KetoLab and the milk fatty acid profile. These can be used as stress indicators, and we can then take action to address the underlying factors. The Lactanet team is always ready to help you interpret your data and guide you in developing an action plan.

Stress 101

When an animal is in a stressed state, oxygenation and energy expenditure increase, digestive processes are disrupted and behaviour is altered. When such disturbances are too intense or occur too frequently, however, they eventually damage organs and disrupt their functions. This is what is known as chronic stress, a state that can lead to a greater risk of disease and metabolic disorders and disappointing production levels.