The transition period in dairy cows is a pivotal time for maintaining health and productivity. During this phase significant physiological, metabolic and dietary changes occur, which present unique challenges for the cow. Addressing these challenges is key to setting the stage for a successful lactation as well as the health of both the cow and her calf. Feeding an effective probiotic throughout the transition period is one part of life cycle feeding and has been shown to support cow health and productivity.
Understanding the transition period
The transition cow faces numerous stressors including:
- Dietary changes
- Changes in dry matter intake
- Group/social changes
- Metabolic demands: Fetal growth, calving, colostrogenesis (when colostrum starts to form in the mammary gland) and lactogenesis (the onset of lactation and milk synthesis in the mammary gland) all impact energy demands.
These stressors, coupled with inflammation and changes in nutrient absorption, increase the cow’s vulnerability to transition phase health challenges.
The role of probiotics
Probiotics are live microorganisms that when administered in adequate amounts confer health benefits to their host. In practice, they support proper function of the gastrointestinal (GI) tract, enhancing the health and productivity of dairy cows during stressful periods such as the transition phase.
Probiotics can:
- Support the cow’s microbiome, encouraging durable and beneficial changes
- Enhance digestive efficiency and nutrient absorption
- Aid in immune modulation, allowing the cow to better manage stress and inflammation
- Compete with pathogens for adhesion sites, reducing the risk of infections
How probiotics support key functions
1. Digestive health and nutrient absorption
A cow’s ability to maintain dry matter intake (DMI) and optimize digestion efficiency during the transition period is essential. An effective probiotic can support DMI pre- and post-calving, helping cows return to prepartum intake levels more quickly. Improved intake is the first step toward managing negative energy balance that frequently occurs during the first weeks of lactation. Improving DMI in the postpartum phase also helps her avoid some of the common metabolic diseases seen during this period like hypocalcemia, ketosis, metritis, etc.
Effective bacilli-based probiotics have been shown to enhance the digestibility of both individual feedstuffs and the overall TMR. These probiotic benefits don’t end there. Increased intestinal villi height, crypt depth and rumen papillae width support the absorptive capacity of the gastrointestinal (GI) tract. Supporting digestion and absorption helps ensure that cows can maximize nutrients from their feed even when DMI is lower than optimal.
2. Barrier integrity and immune support
Stress during the transition period can lead to a compromised gut barrier commonly referred to as leaky gut. This condition reduces nutrient absorption and allows harmful pathogens and toxins to cross into the bloodstream, triggering systemic inflammation. Effective probiotics containing lactic acid bacteria have been shown to support tight junction integrity in the intestinal lining, mitigating the deleterious effects of pathogens such as E. coli, salmonella and clostridium.
Additionally, probiotics help regulate the cow’s immune response during times of heightened stress such as calving. Controlled immune activation minimizes the risk of excessive inflammation while supporting colostrogenesis. The production of high-quality colostrum is critical for the newborn calf, and feeding an effective bacilli-based probiotic during the last three weeks of gestation has been shown to not only improve colostrum quality but also increase the percentage of cows producing high-quality colostrum (greater than 23% Brix).
3. Pathogen control and microbiome balance
Probiotics contribute to pathogen mitigation through direct and indirect inhibition, competitive exclusion and quorum sensing. By occupying adhesion sites in the GI tract, probiotics reduce the ability of harmful bacteria to establish themselves. Furthermore, some bacilli can produce biofilms that protect the gut lining from pathogens, effectively shielding the cow from infections.
Durable changes in the microbiome brought about by probiotic supplementation support eubiosis, or microbial balance, within the GI tract. This balance is essential for proper digestion, nutrient absorption and overall health.
4. Stress management through gut-brain interactions
The gut-brain axis plays a significant role in stress management. Probiotics have been linked to increased serotonin production – the “hormone of well-being” – and reduced cortisol levels – the “stress hormone.” These hormonal changes help the cow better cope with the challenges of the transition period, supporting overall health, productivity and well-being.
Practical considerations
Implementing probiotic feeding as part of a life cycle nutrition strategy involves understanding the specific challenges at each stage of the animal’s life from birth to lactation and matching the needs of the animal to the benefits provided by the bacterial strains in the probiotic.
A path to sustainable dairy production
Transition cow health is a cornerstone of dairy herd productivity and sustainability. Probiotic feeding supports the cow through the most stressful period of her life cycle, helping her overcome challenges related to digestion, nutrient absorption, immune function and stress.
Probiotic supplementation aligns with broader goals of sustainable dairy production by supporting animal health, optimizing feed conversion and reducing the need for medical interventions, including the use of antibiotics. For dairy producers, this approach represents an opportunity to improve herd performance while supporting the well-being of their animals.
As research continues, the role of probiotics in life cycle feeding strategies is likely to expand, offering even greater benefits for dairy producers and the animals in their care.
