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Preventing Heat Stress in Dairy Calves: The Lifelong Impact Starting Even Before Birth

Explore effective measures to prevent heat stress in dairy calves right from their time in utero. Discover practical strategies to guarantee healthier, more productive cattle from birth through adulthood.

As summer approaches, keeping cattle cool becomes crucial for dairy producers. Often, calves aren’t prioritized in these cooling strategies. Still, the impacts of heat stress can start before birth and have lasting consequences. 

Preventing heat stress begins in utero. Research shows that heat stress on pregnant cows can affect fetal development, leading to long-term issues in the calf’s health and productivity

“Heat stress does not discriminate, and it will impact cattle of all ages and physiological states,” emphasized Jimena Laporta, an esteemed assistant professor of lactation physiology at the University of Wisconsin-Madison. Her extensive research on heat stress in cattle has been instrumental in shaping our understanding of this issue.

Understanding these impacts helps you, as dairy producers, implement strategies to mitigate heat stress from the early stages, ensuring healthier, more productive cattle. Your role in this process is vital for the animal well-being and the economic success of dairy operations.

Understanding the All-Encompassing Impact of Heat Stress on Dairy Calves 

“Heat stress affects cattle of all ages and physiological states,” said Jimena Laporta, assistant professor of lactation physiology at the University of Wisconsin-Madison. Her research focuses on prenatal heat stress impacts, highlighting the last trimester of gestation as a critical developmental period. 

Laporta noted, “There is increasing evidence that heat stress during these early developmental windows has long-term effects.” Her studies link in-utero heat stress to shorter gestation periods, lower birth weights, and weaker immune systems. 

Jennifer Van Os, assistant professor and extension specialist in animal welfare at the University of Wisconsin-Madison, stresses the importance of heat abatement strategies for calves. “The goal is to reduce heat gain and promote heat loss,” Van Os stated. 

Van Os recommends elevating hutches and adding extra windows for better ventilation. “When housed in pairs, two calves generate more heat,” she explained, emphasizing the need for adequate ventilation. 

Laporta and Van Os’s research at the University of Wisconsin-Madison provides a comprehensive view of heat stress in calves, from prenatal to post-birth. Their findings underscore the persistent impacts of heat stress, making preventive measures essential for herd welfare and productivity. 

The Crucial Window: Understanding the Impact of Maternal Heat Stress in the Last Trimester of Gestation

The last trimester of gestation is critical for fetal development. The fetus grows and matures during this period, making it highly sensitive to temperature. Maternal heat stress inevitably leads to prenatal heat stress because the fetus relies on the mother for temperature regulation. This can significantly impact fetal development. 

Key physiological processes like organ maturation and cell differentiation are particularly vulnerable. If exposed to high temperatures, organs such as the liver, lungs, and kidneys may not develop properly, leading to long-term deficits. 

Heat stress can also disrupt cell hierarchy and communication, which is essential for healthy development. Cells may not differentiate correctly, compromising tissues and systems. Additionally, thermal stress can impede cell proliferation, resulting in smaller organs and tissues. 

In essence, maternal heat stress means developmental setbacks for the fetus, affecting its health and productivity later in life. Addressing heat stress during this period is crucial for the future well-being of calves.

Revealing the Long-Lasting Consequences of Maternal Heat Stress: Insights from Florida and Wisconsin

Laporta’s studies in Florida and Wisconsin uncovered key findings on maternal heat stress. Calves born to heat-stressed cows had shorter gestation lengths by five days, leading to lighter birth weights (around 10 pounds less). These calves also had a reduced ability to absorb immunoglobulins from colostrum, weakening their immune systems. Furthermore, their overall growth was hindered, with these calves remaining smaller across various dimensions, even after one year, compared to calves from cooled cows.

These calves usually have reduced body size, with shorter body length, chest girth, hip height, and trimmer head circumference, which affects their overall health and productivity. 

Another critical consequence is reduced milk production. Calves stressed in utero have compromised mammary gland development, resulting in lower milk yields across multiple lactations. While they manage around 65 pounds of milk during their first lactation, their cooled counterparts significantly outperform them. Heat-stressed heifers produce less milk and have a reduced productive lifespan of about 12 months. 

These enduring effects highlight the potential benefits of addressing heat stress early. By mitigating prenatal heat stress, you, as dairy producers, can ensure better growth, improved milk production, and longer productive lifespans for your cattle. This can lead to more efficient and profitable farming operations.

Essential Strategies for Mitigating Heat Stress in Calves Both In Utero and Post-Birth 

Mitigating heat stress in calves, starting from the womb, is critical to their health and productivity. Ensure pregnant cows stay cool with shade, fans, and soakers to minimize in-utero heat stress. 

After birth, keep calves comfortable: 

  • Better Ventilation: Elevate hutches on cinder blocks or stands to improve airflow and keep the space cooler.
  • Provide Shade: To reduce heat, use shade cloths that block 80% of sunlight and place hutches under trees or covered areas.
  • Use Fans: In barns, fans and positive pressure tubes can create airflow, calm calves, and refresh the air.

Remember, as dairy producers, you have the ability to significantly reduce heat stress and improve your calves’ long-term health and productivity by implementing these strategies.

The Bottom Line

Addressing heat stress in calves from the prenatal stage is vital for their long-term health and productivity. Heat stress affects them before birth, impacting their immune system, growth, and milk production. Recognize these effects and take proactive measures to cool lactating cows, calves, and dry cows. 

By implementing these cost-effective cooling solutions like better ventilation, shaded environments, and air exchange systems, you can mitigate heat stress. These methods not only promote the well-being of your cattle but also extend their productive lifespan. By adopting these strategies, you can improve your herd’s health and productivity, leading to significant economic benefits and ensuring more resilient livestock.

Key takeaways:

  • Heat stress affects cattle of all ages, including calves and dry cows.
  • Calves experience the long-term effects of heat stress, starting in utero.
  • The last trimester of gestation is a critical period where maternal heat stress impacts fetal development.
  • In utero heat-stressed calves have shorter gestation periods, lower birth weights, and compromised immune systems.
  • Long-lasting consequences include reduced growth, smaller body size, and lower milk production in adult life.
  • Effective heat abatement strategies for pregnant cows include providing shade, using fans, and soakers.
  • Post-birth, calves should also be monitored and provided with cooling solutions like elevated hutches and passive ventilation.

Summary: Dairy producers must prioritize keeping cattle cool to ensure their health and productivity. Heat stress can have lasting effects on calfs, affecting their immune system, growth, and milk production. Research shows that heat stress on pregnant cows can affect fetal development, leading to long-term issues in the calf’s health and productivity. Understanding these impacts helps dairy producers implement strategies to mitigate heat stress from the early stages, ensuring healthier, more productive cattle. The last trimester of gestation is critical for fetal development, and maternal heat stress can lead to prenatal heat stress, significantly impacting fetal development, organ maturation, and cell differentiation. Heat-stressed calves have shorter gestation lengths, lighter birth weights, reduced immune system strength, and hindered overall growth. To mitigate heat stress, dairy producers should ensure pregnant cows stay cool with shade, fans, and soakers, keep calves comfortable, provide shade, and use fans in barns. Implementing cost-effective cooling solutions can significantly reduce heat stress, promote cattle well-being, and extend their productive lifespan.

Decoding the Impact of Housing Systems on Digital Dermatitis in Dairy Cows: A Genetic Study

Delve into the influence of housing systems on digital dermatitis in dairy cows. Could genetic evaluations pave the way for enhanced bovine health across varied living conditions? Uncover the research insights here.

Imagine walking barefoot on gravel daily; the discomfort of digital dermatitis (DD) in dairy cows feels similar. This painful hoof disease significantly hampers cows’ mobility, milk production, and the economic health of dairy farms. 

The environment in which cows are housed plays a critical role in DD’s incidence and severity. Housing systems such as conventional cubicle barns (CON) and compost-bedded pack barns (CBPB) have distinct impacts on disease management. Understanding these housing-related nuances is vital for farmers and researchers working to reduce DD’s impact. 

This research utilizes detailed phenotyping data from over 2,980 observations of Holstein-Friesian and Fleckvieh-Simmental cows on ten farms. It investigates the genetic variances linked to DD stages: sick, acute, and chronic. Through genome-wide association studies (GWAS), the study identifies potential candidate genes and assesses genotype × housing system interactions. This comprehensive analysis seeks to uncover genetic factors that can inform breeding programs and enhance animal welfare, regardless of their rearing environment. 

Introduction: Understanding Digital Dermatitis in Dairy Cows

Digital Dermatitis (DD) is an infectious disease impacting the bovine foot, particularly the plantar skin bordering the interdigital cleft. This condition ranges from initial lesions to chronic, painful wounds, affecting dairy cows‘ mobility and well-being. 

The development of DD involves a mix of environmental, genetic, and management factors. Housing systems, especially conventional cubicle barns, create conditions ripe for DD, with moisture and contamination fostering pathogen growth. Nutritional imbalances, poor foot hygiene, and milking routines further increase risk. Notably, genetic predispositions also play a role; some cattle lines are more susceptible, emphasizing the need for genetic research to combat DD. 

The economic and welfare impacts of DD are significant. Economically, it causes losses through reduced milk production, higher veterinary costs, and culling of severely affected cows. Welfare-wise, the pain and lameness from DD seriously affect cattle comfort and health, raising ethical concerns in livestock management. Therefore, addressing DD with better housing, management practices, and genetic selection is crucial for sustainable dairy farming.

Exploring Housing Systems: Cubicle Barns vs. Compost-Bedded Pack Barns

Housing systems play a pivotal role in dairy productivity and cow health and welfare. The primary systems include conventional cubicle barns (CON) and compost-bedded pack barns (CBPB), each impacting the Prevalence and severity of digital dermatitis (DD). 

In CON setups, cows rest on mats or mattresses over concrete floors. This controlled environment supports restful ruminating but can worsen claw disorders due to constant exposure to manure and poor ventilation. Conversely, CBPB systems offer cows a spacious environment with composting bedding of sawdust or wood shavings, which is more comfortable and supports better hoof health by reducing pathogens through microbial activity. 

The flooring material is crucial. Concrete floors in CON systems retain moisture and manure, fostering bacteria that cause DD. CBPB systems’ drier, more sanitary bedding leads to fewer DD incidences. 

Hygiene practices, essential for DD control, differ by system. CON systems require regular scraping and washing, while CBPB systems depend on managing bedding moisture and microbial activity. Both approaches aim to reduce bacterial loads and curb DD spread. 

Cow comfort, dictated by the housing system, also affects DD prevalence. CBPB’s spacious, free-roaming environment reduces stress and improves immune function, making cows less prone to DD. In contrast, CON systems’ restrictiveness can increase anxiety and susceptibility to claw disorders. 

In summary, the choice between cubicle barns and compost-bedded pack barns significantly impacts cow health and the incidence of DD. Prioritizing comfort and hygiene in housing systems leads to healthier, more productive cows with fewer claw disorders.

Unveiling Genetic Interactions Between Housing Systems and Digital Dermatitis in Dairy Cows

ParameterConventional Cubicle Barns (CON)Compost-Bedded Pack Barns (CBPB)Overall Dataset
Number of Observations1,4501,5302,980
Number of Cows8118991,710
DD-Sick Prevalence (%)HigherLower20.47%
DD-Acute Prevalence (%)HigherLower13.88%
DD-Chronic Prevalence (%)HigherLower5.34%
Heritability – DD-Sick0.160.160.16
Heritability – DD-Acute0.140.140.14
Heritability – DD-Chronic0.110.110.11
Genetic Correlation (CON and CBPB) – Same Traits~0.80N/A
Genetic Correlation – Within Traits (DD-Sick, DD-Acute, DD-Chronic)0.58 – 0.81
Significant Candidate Genes for DD-Sick and DD-Acute (SNP Main Effects)METTL25, AFF3, PRKG1, TENM4
Significant Candidate Genes (SNP × Housing System Interaction)ASXL1, NOL4L (BTA 13)

The genetic study on digital dermatitis (DD) in dairy cows examined the influence of different housing systems on the disease. This research aimed to understand the interaction between cow genotypes and their environments. It focused on DD stages—DD-sick, DD-acute, and DD-chronic—in conventional cubicle barns (CON) and compost-bedded pack barns (CBPB). Herds were selected to ensure similarities in climate, feeding, and milking systems. Still, they differed in housing setups to isolate housing-specific impacts on DD. 

Using 2,980 observations from 1,710 cows and 38,495 SNPs from 926 genotyped cows after quality control, the study employed single-step approaches for single-trait repeatability animal models and bivariate models to estimate genetic parameters and correlations. GWAS identified specific SNPs and their interactions with housing systems. Heritabilities for DD stages and genetic correlations between the same traits in different housing systems were also calculated. 

Results showed higher DD prevalence in CON systems compared to CBPB. Heritabilities were 0.16 for DD-sick, 0.14 for DD-acute, and 0.11 for DD-chronic, with a slight increase in CON. Genetic correlations between the same DD traits in different housing systems were around 0.80, indicating minimal genotype × housing system interactions. Correlations among DD stages ranged from 0.58 to 0.81, showing their interconnectedness regardless of the housing system. 

GWAS results were varied for DD-acute and DD-chronic, indicating complex pathogenesis. Candidate genes affecting disease resistance or immune response included METTL25, AFF3, PRKG1, and TENM4 for DD-sick and DD-acute. SNP × housing system interactions highlighted ASXL1 and NOL4L on BTA 13 for DD-sick and DD-acute. 

For dairy farmers, these findings underline the impact of housing systems on the Prevalence and progression of DD and the potential genetic implications. Our comprehensive study provides actionable insights for dairy farmers globally. 

Notably, DD prevalence was significantly higher in CON, highlighting the challenging environment of cubicle barns compared to the more welfare-oriented CBPB system. These insights are crucial as they affect animal health and have economic ramifications, including reduced milk production and increased treatment costs. 

We examined genetic evaluations across these environments and found that heritabilities for DD traits (DD-sick, DD-acute, DD-chronic) were slightly higher in the CON system. Still, overall genetic parameters remained consistent across both systems. Despite different housing practices, the genetic predisposition to DD remains relatively stable. 

Genetic correlations between different DD stages (ranging from 0.58 to 0.81) suggest a common underlying genetic resistance mechanism crucial for developing targeted breeding programs. Furthermore, GWAS pinpointed several candidate genes, such as METTL25, AFF3, PRKG1, and TENM4, with significant implications for disease resistance and immunology. 

This research underscores the importance of genotype-environment interactions, even though these were minimal in housing systems. Integrating genomic insights with practical management strategies can improve animal well-being and farm productivity as the dairy industry evolves. 

By applying these findings, dairy farmers can make informed decisions about housing systems and genetic selection, enhancing economic and animal health outcomes. This study calls for the industry to adopt evidence-based practices rooted in rigorous scientific research.

Genetic Evaluations: From Genotypes to Phenotypes

The research meticulously analyzed data from 1,311 Holstein-Friesian and 399 Fleckvieh-Simmental cows, totaling 2,980 observations across three digital dermatitis (DD) stages: DD-sick, DD-acute, and DD-chronic. This granular phenotyping clarifies how DD stages manifest in different environments. By categorizing it into conventional cubicle barns (CON) and compost-bedded pack barns (CBPB), the study highlights the environmental impact on genetic expressions related to DD. 

Quality control of 50K SNP genotypes refined the data to 38,495 SNPs from 926 cows. This dataset formed the basis for estimating genetic parameters through single-step approaches. The genetic correlations between DD traits and housing systems uncovered genotype × environment (G×E) interactions. 

Heritability estimates were 0.16 for DD-sick, 0.14 for DD-acute, and 0.11 for DD-chronic, indicating the genetic influence. Notably, these estimates and genetic variances slightly rose in the more stressful CON environment, indicating heightened genetic differentiation under challenging conditions. Genetic correlations between the same DD traits across different housing systems were around 0.80, showing minimal G×E interactions. 

Genome-wide association studies (GWAS) revealed heterogeneous Manhattan plots for DD-acute and DD-chronic traits, indicating complex biological pathways. Despite this, several shared candidate genes like METTL25, AFF3, PRKG1, and TENM4 were identified, showing their potential role in managing DD through genetic selection. 

For SNP × housing system interactions, genes such as ASXL1 and NOL4L on chromosome 13 were relevant for DD-sick and DD-acute. These findings illustrate how specific genetic markers interact with environmental factors. Overall, the minimal impact of genotype × housing system interactions supports robust genetic evaluations for DD across diverse environments, aiding broader genetic selection strategies in dairy cow populations. 

The Bottom Line

This study highlights the importance of detailed phenotyping and genetic evaluations in understanding digital dermatitis (DD) in dairy cows. By examining 1,710 Holstein-Friesian and Fleckvieh-Simmental cows in conventional cubicle barns (CON) and compost-bedded pack barns (CBPB), the research provided crucial insights into the Prevalence and heritability of DD. It found slightly higher genetic differentiation in the more challenging CON environment but minimal genotype × housing system interactions, indicating a limited impact on genetic assessments. Essential genes like METTL25, AFF3, PRKG1, and TENM4 were identified as necessary for disease resistance and immunology. 

Understanding how housing systems affect DD is crucial. It helps improve management practices to reduce DD prevalence, enhancing cow welfare and farm productivity. It also improves genetic selection by identifying traits that enhance DD resistance in specific environments, benefiting long-term herd health and sustainability. This insight is vital for today’s dairy operations and future breeding programs. 

Future research should delve into the long-term impact of housing systems on genetic traits linked to DD resistance. Exploring other environmental and management factors, like nutrition and milking routines, would offer a fuller understanding of DD. Personalized genetic interventions tailored to specific farm environments could be a game-changer in managing this disease in dairy cows.

Key Takeaways:

  • The study analyzed 2,980 observations of DD stages, differentiating between DD-sick, DD-acute, and DD-chronic across two housing systems: conventional cubicle barns (CON) and compost-bedded pack barns (CBPB).
  • Heritabilities for DD were slightly higher in the CON environment, suggesting a stronger genetic differentiation of the disease in more challenging conditions.
  • Despite varying heritabilities, genetic correlations between the same DD traits in different housing systems were high, indicating minimal genotype × housing system interactions.
  • GWAS highlighted significant candidate genes such as METTL25, AFF3, and PRKG1, which play roles in disease resistance and immunology.
  • This research underscores the importance of considering housing systems in genetic evaluations to enhance disease management and improve cow welfare.


Summary: Digital Dermatitis (DD) is a severe hoof disease that affects dairy cows’ mobility, milk production, and farm economic health. Housing systems like conventional cubicle barns (CON) and compost-bedded pack barns (CBPB) have distinct impacts on disease management. CON setups, which support restful ruminating but can worsen claw disorders due to constant exposure to manure and poor ventilation, have higher DD-sick prevalence than CBPB systems (5.34%). Both approaches aim to reduce bacterial loads and curb DD spread. CBPB’s spacious, free-roaming environment reduces stress and improves immune function, making cows less prone to DD. A study found higher DD prevalence in CON systems compared to CBPB. Understanding how housing systems affect DD is crucial for improving management practices, enhancing cow welfare, and improving genetic selection.

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