Dairy cows are known to be sensitive creatures and their welfare remains a topic for researchers focusing mainly on cow health, behavior and physiology. Although there is still a lack of knowledge and information on the subject, a number of studies focus on the cow’s ability to cope with external and internal farm environments and conditions, as well as the behavioral response to a number of health and nutritional situations. A state of well-being can be phenomenally described by five basic freedoms: freedom from pain—injury, disease, physical and thermal discomfort, fear and distress, and freedom from hunger, thirst, and malnutrition. But how easy is it to offer freedom to all cows when it comes to dairy farming?
Importance of production systems
Dairy operations can be classified into pasture-based and/or indoor production systems. Domestic production systems are steadily expanding to meet growing demand and expand markets for dairy products, but land for pasture-based production remains limited. A few studies have compared welfare status between different livestock systems, but not enough to draw a firm conclusion. Although welfare in pasture-based farming is considered better for dairy consumers, largely due to cow freedom, there are potential areas of concern between the dairy production cycle. This mainly includes severe adverse food supply and exposure to unpredictable weather conditions for cows. Few studies have measured physiological parameters yet to compare welfare status, with higher levels of non-esterified fatty acids (NEFA), β-hydroxybutyrate and triglycerides after parturition consistent with limited energy supply in pasture-based bred cows.
Subclinical metabolic diseases
Long-term genetic selection for high-yielding cows continues to further undermine welfare fundamentals as they increase cow productivity and make calving intervals more susceptible to negative energy balance (NEB) and nutrient supply. After that, the occurrence of metabolic diseases is inevitable. Subclinical metabolic diseases are silent profit consumers for modern dairy operations, and thus management and elimination of such stressors can have an overall financial-positive effect on the herd.
Farm design and colostrum management
Farm design and breeding system can also protect and/or expose cows to adverse climatic conditions (cold and/or heat), not only due to metabolic shift outside the thermo-neutral zone, but also potential for welfare due to reduced productivity. remains a threat. false time known to cause stress. Stress factors involve the activation of the hypothalamic-pituitary-adrenal axis to increase cortisol levels. Cows with a low body concentration score (BCS) are more susceptible to stress in cold and wet conditions. In addition to growing temperatures, exposure to sunlight can be beneficial, as studies have shown positive effects on cardiovascular health, vitamin D synthesis, lower blood pressure, and positive immune function. Farm design and colostrum management for the welfare of young animals and first-calving heifers are also important parameters in determining lifetime productivity. Heifers grazed extensively early in life were more exposed to gastrointestinal parasites and showed anthelmintic resistance with lower growth rates during puberty.
Nutritional science and management practices
The Holstein Friesian being a dominant breed requires a science-based approach to meet its metabolic demands, especially in the last week(s) before and after calving (transition period). More than 10% of cow treatments are associated with malnutrition, with hypocalcaemia, mastitis, lameness and reproductive problems being the main metabolic abnormalities during transition. Poor nutritional management during transition predisposes cows to clinical ruminal and abomasal disorders (DA), and subclinical ruminal acidosis (SARA) is often the highest risk factor. SARA has been characterized as a condition in which the rumen experiences a pH range between 5.2 and 6 over a long period of time, resulting in the accumulation of volatile fatty acids (VFA). Acids can damage the rumen epithelium, which reduces the absorption rate of VFAs. Usually, a total mixed ration (TMR) is offered in the household. Evenly cut and mixed forages can prevent forage sorting, thus promoting a more palatable and pH balanced forage for cows. Pasture-based farming and entirely grass-fed cows are more susceptible to acidosis because feed consumption is based on fast-digesting grass, low in structural carbohydrates, and inappropriate feeding times. Although individual cows may express behavioral needs, high-yielding cows are more susceptible to SARA, which later develops into a syndrome usually associated with the following syndrome. Ruminitis – Laminitis.
Best wellness practices
Monitoring performance and other parameters, including BCS loss/gain relative to dietary inputs, appears to be key to ensuring best welfare practices. Fat cows at parturition have reduced feed intake during early lactation, leading to increased NEB and increased tissue nutrient mobilization. BCS losses due to high NEB result in subclinical endometritis, which leads to reduced fertility. Often overlooked, calving ease is a critical welfare parameter, as difficult calving and twinning lead to retained placenta, metritis and mastitis. Infertility is caused by metritis by altering ovarian function, cycle and oocyte competence. Mastitis susceptibility is hereditary and is associated with reduced fertility. Increased risk of higher intramammary infections and high somatic cell count (SCC) due to greater exposure to environmental pathogens is more common in the household. SCC is often associated with low enzymatic activity due to major deficiencies of vitamins and micronutrients, more specifically vitamin E and selenium deficiency. Mastitis before and after parturition has also been shown to be associated with other factors, including low protein and amino acid intake, electrolyte and acid-base imbalances, and heat stress levels.
Lameness of dairy cattle
Lameness remains a key health and welfare parameter. Lame cows experience severe pain, discomfort, and are more likely to reduce feed intake due to fewer visits to feedlots and lower rumen motility (related to NEB). All previous metabolic abnormalities have a complex etiology. In addition, bacterial infections such as digital dermatitis and dysfunction of the horn-producing paw epithelium cause heel ulcers. Lameness is the second largest cause of premature culling in modern dairy operations (after infertility). Studies have shown that up to 60% of domestic cows are clinically lame, with cases becoming significant within 180 days of calving. The digital pad of the claw is oil-impregnated for shock absorption. Its thickness is directly related to weight loss shortly after calving and has been shown to be associated with claw horn damage up to 3-4 months of lactation. Although not yet well defined, intestinal metabolites, disease-causing toxins, and menopausal hormonal changes may be additional factors associated with claw horn damage. Skin lesions (pelvis and knees) are also indicators of cow welfare with studies showing a positive correlation between skin lesions and lameness.
To date, dairy profit margins continue to be squeezed as production costs have risen faster than milk prices. To overcome this, farmers breed cows with higher genetic potential, which leads to higher sensitivity to energy, nutrients and overall welfare gap. As the dairy market focuses on animal welfare claims in an era of continued efforts to reduce herd pharmaceutics, the dairy industry needs to re-appraise the use of certain feed additives with nutritional effects in dairy farming. Animal nutrition and feed science is a priority for investment research to ensure profit for the farmer and ensure animal welfare.
References are available upon request.