Other Management Articles
- Building A Herd of High-Producing, Healthy Cows with Low Involuntary Culling
- Culling Heifers: When and Why and the Impact on Herd Economics
- Economics Matter in Culling Decisions
- What is an ideal BCS at calving?
- Facts about Somatic Cell Counts
- First Layer of Defense Against Mastitis
- The When and Why of Milking Procedures
- Are Mastitis Vaccines a “Cure All”?
- Growing Heifers to Be Your Best Cows
- A Look in the Mirror
- Fertility Potential: The Bull + The Cow + The Inseminator + The Environment
The overall non-completion rate of dairy heifers, which represents the percentage of heifers failing to enter the milking herd, is a pivotal aspect of dairy farming, like a comprehensive snapshot of culling practices. Dairy heifer rearing significantly influences the future productivity and profitability of a herd. Nonetheless, addressing the challenges associated with heifer non-completion remains a pressing concern for dairy farmers worldwide. This issue stems from a multitude of factors, spanning from management techniques to environmental influences. Understanding these elements is imperative for devising effective strategies to enhance heifer rearing outcomes and overall farm efficiency.
One method to gauge this rate involves tallying all losses incurred monthly from birth until calving, then dividing this figure by the total inventory for the month (inclusive of calving heifers and those lost). This provides a representative assessment of the situation. Ideally, a successful heifer program should see around 90% of born alive heifers entering the milking herd, with these heifers reaching milking age (around 2-years-old) at 90% of their mature size. The most successful herds will target above 90% entering the milking herd and include stillborn losses in that goal.
From a theoretical standpoint, this calculation typically includes all animals sold for dairy purposes, though sometimes these are excluded for separate analysis. Those sold for dairy are considered to have "completed" their purpose. When looking simply at herd growth variables, you need to factor in animals to be sold to gauge heifer rearing and environment. When looking at building a breeding strategy, you might want to factor animals to be sold into the non-completion rate, if there is a drive to continue to sell dairy replacements. The non-completion rate can range from 5% to 30%, with an average of approximately 15%, representing a significant opportunity for improvement in many herds. Successful management allows for fine-tuning of breeding strategies, including the use of sexed and beef semen. Conversely, failure not only diminishes this opportunity but also results in damaged calves, leading to further non-completion and underperformance upon integration into the milking herd. 
Stillborn calves, while not factored into the non-completion rate, deserve equal attention during evaluations. Each stillborn calf represents a missed opportunity within the heifer inventory. High stillborn rates not only increase the number of calves that need to be replaced but also indicate a heightened risk of birthing complications, potentially resulting in more damaged calves. Conversely, herds with low stillborn rates typically experience fewer losses among pre-weaned calves, a testament to effective management practices and healthier calves. Globally, stillborn rates average between 6% to 8%, but I encourage targeting only a 1% loss rate. This target emphasizes animal welfare and shifts the discourse away from detractors of farming practices. While this is a challenging benchmark, some exemplary herds are approaching this level, and it should be an industry goal.
Areas contributing to non-completion include preweaning losses, post-weaning challenges, and culling practices. Preweaning losses worldwide average around 6% to 8%, with a target of under 2% for optimal animal welfare. This target is reached consistently by well managed herds.
Post-weaning mortality should ideally be less than 2% pre-breeding and another 1% post-breeding until calving. This is achievable. A long-range target of less than half a percent is where we should be headed. High survivability and health targets create a discussion point within an operation and informs the public of high standards that the industry is working to achieve.
Culling practices are categorized into biological, or salvage, culling and economic culling. Salvage culling should be limited to 3-5%, primarily consisting of animals deemed unfit for lactating due to damage. Breeding failure falls into this group also. Herds with lower mortality typically experience lower biological culling rates, as healthier animals are less prone to damage and reproductive failures. Rapid or ideally growing heifers tend to reach puberty two to three months before the start of breeding, which increases the likelihood of successful conception. Problem animals not only have delayed puberty but will sometimes stay anestrus for an extended period. These animals not only have increased rearing costs, but they have now been predisposed to have higher reproductive failure in the following lactation.
Planned economic culling involves leveraging genomic knowledge to remove heifers incompatible with the herd's future profile, allowing for the removal of random genetic failures. In your genetic strategy, plan for some of these heifers to be removed.
Challenges in the areas below often lead to difficulty in maintaining sufficient pregnancies to sustain the milking herd, resulting in extended breeding periods, retention of poor genetics, and “rescue” of damaged animals. This, in turn, results in increased production variation in the first lactation. Addressing these challenges requires initiative, taking management approaches centered around specific focal points:
Nutrition: Ensuring adequate nutrition tailored to different age groups of dairy heifers is crucial for their growth and development. Imbalances in key nutrients can hinder growth and increase the risk of non-completion. Transitions in nutrition such as milk feeding rates, weaning processes, protein transitions, and the move to high forage play a big part in success or failure.
Health and Disease: Proactive health management programs, including vaccination protocols and disease prevention strategies, are essential for mitigating health issues that can compromise heifer development and ultimately lead to non-completion.
Housing and Environment: Providing adequate housing and ideal environmental conditions that promote heifer comfort and well-being is vital for preventing stress-related issues and growth challenges.
Genetics and Breeding: Emphasizing genetic selection for desirable traits and collaborating with breeding programs can enhance the genetic potential of heifers, ensuring their suitability for entry into the milking herd.
Management Practices: Implementing effective management practices, such as extended ideal colostrum management, routine health monitoring and strategic deworming, is critical for optimizing heifer growth and reducing the risk of non-completion. Enhance the management practices through staff training, monitoring performance metrics, and implementing best practices for heifer rearing.
By addressing these key factors through a holistic approach to heifer management, dairy producers can improve heifer rearing outcomes and increase the likelihood of heifers successfully entering the milking herd. This, in turn, contributes to the long-term success and sustainability of dairy operations.