The transition period in dairy cows is a critical phase in their production cycle; cows experience several physiological, metabolic, and environmental changes. Ultimately, the immune system will be disrupted, leading to inflammation, oxidative stress, and excessive lipid mobilization. These challenges require a holistic solution approach.
R&D Program Manager
Lallemand Animal Nutrition
Despite intensive academic and industry focus, the transition period remains a big challenge to animal welfare, farm profitability, and dairy sustainability. Research shows that 75% of dairy cow diseases happen in the first month after calving (LeBlanc et al., 2006), while 65% of clinical mastitis cases occurring during the first two months of lactation originated during the dry period (Cobirka et al., 2020). Post-partum diseases such as ketosis has been recently identified to cause an annual losses per cow of 134 USD (average from 183 milk-producing countries) but is also considered as gateway diseases, greatly reducing the chance of full productivity throughout the subsequent lactation (Goff, 2008), and has been associated with increased odds of other dairy cattle diseases (Rasmussen et al., 2024).
The old dogma or principle emphasizes that adipose tissue-released non-esterified fatty acids (NEFA) and the resulting hepatic-derived ketones coupled with hypocalcaemia lead to immune suppression, which is responsible for transition disorders. In other words, this old dogma suggested these metabolites and hypocalcaemia were causal to transition cow problems. However, the new insight from research takes a more holistic and preventive strategy in managing dairy cows during the transition, placing inflammation as a cornerstone of transition disorders (Horst et al., 2021).
Calving transition presents the cow with multiple metabolic stresses that often lead to pathological permeability of the intestinal wall, what is called “leaky gut syndrome”. A leaky digestive system and immune activation at calving can be the root cause of transition disorders. The physiological, environmental, and psychological stressors during the transition period disrupt barrier integrity, increasing permeability at epithelial interfaces (e.g., uterine, mammary, intestinal, and lung), which are exposed to pathogens and colonised by commensal microorganisms. When microorganisms breach the epithelial barrier (through the leaky gut), activation of the immune response leads to inflammation — a result of lipopolysaccharide (LPS) translocation into the systemic circulation (Figure 1).
The aim during the transition period is to limit inflammation, extract more energy from the diet, and limit oxidative stress. On the same leaf, the several challenges during the transition period evidence the need for a holistic approach. The goal is to optimize milk production to ensure producers’ profitability, cow health, longevity and welfare, and the environment while offering consumers high-quality and safe dairy products. The supplementation of live yeast is on the top list of additives to ensure a smooth transition period in dairy cows.
WHY DO COWS EXPERIENCE INFLAMMATION, EXCESSIVE LIPID MOBILIZATION AND OXIDATIVE STRESS AROUND CALVING?
Inflammation during the transition period is associated with the stress and changes that occur in the cow’s body as it prepares for parturition. What is also observed during the transition period is increased metabolic demand due to changes in nutrient intake and metabolism, often leading to a negative energy balance (NEB) and metabolic stress. Metabolic stress is characterized by excessive lipid mobilization, immune and inflammatory dysfunction, and oxidative stress. This period is the largest swing of metabolic status of a dairy cow in a short period of time. These three processes are intrinsically linked (Figure 2) and result in immune and metabolic disorders associated with an increased risk of metabolic and infectious diseases.
In addition, the elevated NEFA and beta-hydroxybutyrate (BHB) concentrations from excessive lipid mobilisation and hypoglycaemia, as glucose is required for immune cell function, are important contributors to the periparturient immune dysregulation and inflammation (Figure 2). Increased lipid mobilization during NEB can lead to an increased risk of the metabolic disorder, such as ketosis. Transition cows are susceptible to oxidative stress due to the increased metabolic activity associated with late pregnancy, parturition, and the onset of lactation. The usually observed low dry matter intake (DMI) means a limited supply of natural antioxidants from the feed.
REDUCING THE INCIDENCE OF INFLAMMATION
Transition cows often experience inflammation around calving due to several factors including environmental and management, metabolic demands and physiological changes. These factors lead to local inflammation in the uterus, mammary gland and digestive system, whereby lipopolysaccharides (LPS) are released in the whole body causing systemic inflammation.
In the uterus, bacterial contamination and injuries during calving often lead to inflammation. The mammary gland is highly susceptible to bacterial infections (causing systemic inflammation), with intramammary infections most common during early involution (dry-off) and colostrogenesis. On the other end, the ruminant digestive system experiences stress due to dietary changes that can compromise gut integrity, leading to leaky gut and systemic inflammation. Diet changes and the accompanying stresses can modify the rumen microbe leading to a higher risk for subacute ruminal acidosis (SARA) that will damage the rumen wall epithelium, creating a leaky gut.
Overall, during immune activation and inflammation, nutrients and energy are diverted from productive purposes to support the immune system, leading to economic consequences such as decreased production, inefficient feed utilisation, poor reproduction, and treatment costs.
Research shows a shift to higher-energy diets during the transition period disturbs the microbiota balance in the rumen, compromising rumen health (Bach et al., 2018); parturition is shown to disturb rumen tight junction, leading to LPS passage and local inflammation. In this research by Bach et al. (2018), the supplementation of a rumen-specific live yeast Saccharomyces cerevisiae CNCM I-1077 (LEVUCELL SC) fed before calving helped the rumen wall better prepare for the stress encountered around calving (Figure 3). The rumen-specific live yeast improved rumen wall integrity (reinforcing the tight junctions) and resistance to rumen wall inflammation (more resistant to LPS and inflammatory challenges related to diet changes) (Figure 3). The trial results also showed that S. cerevisiae CNCM I-1077 increases energy extraction from the diet to mitigate negative energy balance (NEB); it improved post-calving dry matter intake by 2.5 kg/cow/day and milk production by +6 kg/cow/day.
REDUCING THE EFFECTS OF OXIDATIVE STRESS
As shown in Figure 2, oxidative stress increases inflammation, supplementation of antioxidant additives would help enhance the production of endogenous antioxidants in the body tissues. Research has proven that selenium-enriched yeast provides the best bioavailable organic Se, an essential cofactor for primary antioxidants. In a trial conducted by Lallemand Animal Nutrition in 2017 at the National Research Institute of Animal Production in Poland, the potential of Se-enriched yeast (ALKOSEL) was confirmed when provided to the cow before parturition on maternal transfer through colostrum and milk. Results showed a significantly higher selenium secretion into colostrum and milk compared to control cows supplemented with an inorganic selenium source.
BALANCING LOWER GUT MICROBIOTA
The ruminant digestive system consists of the rumen and the lower gut. The intestinal epithelia of the rumen and the lower gut serve both metabolic and barrier integrity roles. The lower gut is a simple columnar epithelium, which consists of both absorptive epithelial cells and a myriad of immune-related cells with extensive defence mechanisms to protect the epithelial barrier. The lower gut is equally important to the rumen during the transition period to ensure the health of the ruminant digestive system.
Research conducted at Guelph University and presented at the American Dairy Science Association (ADSA) Conference in 2024, assessed the effects of a specific lower gut live yeast supplementation, from a Saccharomyces c. boulardii yeast CNCM I-1079 (PROTERNATIVE). The results showed that cows supplemented from 1 month before calving to 2 months after calving show mitigation of the negative consequences of transition at the gut level. The yeast maintained and strengthened intestinal barrier function, and gut integrity and improved the microbiota balance while mitigating the immune response. The yeast also promoted energy allocation towards milk quality while minimizing inflammatory responses.
CONCLUDING REMARKS
Although dairy cow transition challenges might sound inevitable, an effective management approach goes a long way in mitigating the problems. A holistic solution approach aims to limit inflammation, extract more energy from the diet, and limit lipid mobilization and oxidative stress during the transition period. Proper management of inflammation and maintenance of epithelial integrity during the transition period helps improve cow health and performance, yielding high economic outcomes. Nutritional feed additives such as live yeast are key management solutions that can help, among other management actions, to ensure a smooth transition period in dairy cows.
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References
1.Abuelo A., Joaquín Hernández., José L. Benedito., Cristina Castillo., 2019. Redox Biology in Transition Periods of Dairy Cattle: Role in the Health of Periparturient and Neonatal Animals. Antioxidants 8, 20.
2.Cobirka M., Vladimir Tancin., Petr Slama., 2020. Epidemiology and Classification of Mastitis. Animals 10, 2212.
3.Goff, J. P. (2008). The monitoring, prevention, and treatment of milk fever and subclinical hypocalcemia in dairy cows. The veterinary journal, 176(1), 50-57.
4.Horst E. A., Kvidera S. K., Baumgard L. H., 2021. Invited review: The influence of immune activation on transition cow health and performance—A critical evaluation of traditional dogmas. J. Dairy Sci. 104, 8380–8410.
5.LeBlanc S. J., Lissemore K. D., Kelton D. F., Duffield T. F., Leslie K. E., 2006. Major Advances in Disease Prevention in Dairy Cattle. J. Dairy Sci. 89, 1267–1279.
6.Pineda A., Jantzi S., Dekraker K., Cartwright S., Boerefyn M., Villot C., Kvidera S. K., Steele M. A., 2024. Effects of live yeast Saccharomyces cerevisiae boulardii CNCM I-1079 supplementation during the late dry and early postpartum periods on feed intake and production responses. American Dairy Science Association Conference (ASDA). Oral Presentation.
7.Rasmussen, Philip; Barkema, Herman W.; Osei, Prince P.; Taylor, James; Shaw, Alexandra P.; Conrady, Beate et al. (2024): Global losses due to dairy cattle diseases: A comorbidity-adjusted economic analysis. In Journal of dairy science 107 (9), pp. 6945–6970. DOI: 10.3168/jds.2023-24626.
About Clothilde Villot
Clothilde Villot is working for Lallemand Animal Nutrition as an R&D Program Manager for silage and ruminants. With a strong background in animal science, her role is to ensure that cutting-edge research translates into tangible improvements on farms.
