Is your herd's culling strategy driven by a survival of the fittest mentality or a focus on improving the overall quality of the herd? The goal is to maintain a population of highly productive and healthy cows that can thrive through multiple lactations. By minimizing involuntary culls and biological factors leading to animals leaving the herd, we increase the chances of retaining more cows for extended lactation cycles. This approach opens the possibility for a cow to successfully complete one lactation and seamlessly transition into another. However, reality shows that poor performers in one lactation tend to struggle with production in subsequent lactations as well. In light of this, we must question whether these underperforming cows are suitable to shape the future of our herd. 

Generally, cows in their third lactation and beyond exhibit the highest levels of production within a herd for two primary reasons. First, full maturity allows cows to reach their maximum potential. Second, the removal of low-producing and problematic cows leaves behind a group of survivors — healthy, high-producing cows that have bred successfully. If we opt to reduce culling without adjusting other parameters, less productive cows may persist through additional lactation cycles, ultimately dragging down average production levels — a scenario that goes against our objectives. It is crucial to establish a survivor bias towards higher production within the herd to maintain optimal performance. 

Creating a low biological cull system is not about retaining problematic cows for further lactations but rather empowering economic decision making. Dr. Albert DeVries' research in 2019 highlighted that the optimal performance within a herd is achieved with a cull rate ranging from 20% to 25%. He emphasized the importance of balancing factors such as herd replacement cost, maturity and aging costs, genetic opportunities, and calf value to determine the economically ideal productive lifespan of cows. These considerations should guide our efforts to effectively manage and understand these factors.

25% Cull Rate = Maximizing Each Factor Through Management 

  • Calf Value Opportunity Costs: A value, but a small component of overall profit. Can we maximize the value of each calf by choosing the value? 

  • Aged Cow Cost: Health cost increases with older cows and urgent cull cow value decreases. Can we manage the issues that impact these costs and losses? 

  • Lack of Maturity Cost: Mature cows should produce 25% more milk at peak and 15% more total milk than first lactation. If we have a lower daily profit cow, should we replace her with a better daily profit heifer? 

  • Herd Replacement Cost: Top three largest expense on a dairy. Replacement is expensive, but we should not wait to replace a low daily profit animal for one with a higher profit potential. 

  • Genetic Opportunity Cost: Putting better genetics into the milking herd is a goal. We need to keep cows to enjoy these genetic gains. 

In a subsequent study in 2022, Dr. DeVries explored the potential of 50% of milking cows performing below the herd average. The 2022 research found that investing in raising additional heifers and culling below-average cows, instead of solely focusing on problematic or salvage cows, may present economic benefits. His findings suggested that an optimal 39% cull rate was ideal for the example herd, considering variables like cull cow prices, feed costs, and milk prices. While these figures are not absolute and are subject to market fluctuations, they serve as a framework for evaluating our own decision-making processes. The key takeaway is that achieving an economically optimal dairy cow replacement rate hinges on making informed culling and breeding decisions. 

The concept of economic culling revolves around maximizing the economic potential of each space within the dairy. Prolonging this economic viability leads to better overall dairy performance. Removing below-average animals in their first lactation can enhance economic gains compared to retaining them until subsequent lactations. While this decision may be challenging, focusing on economic efficiencies early on can yield significant returns. 

Replacing below-average first lactation animals with average performers can be beneficial from both economic and environmental perspectives. Selecting healthier, higher-producing cows for multiple lactations not only boosts profitability but also reduces the negative environmental impact compared to retaining low producers. Striving to maintain a herd with high-producing, long-lasting cows aligns with sustainable practices and enhances overall efficiency. 

It is true that a first lactation animal with poor performance may show improvement in a second lactation. However, those in the bottom 25% typically do not progress to reach the top 25%. Instead, they may advance from being poor performers to still falling below the average mark. This presents an opportunity to replace such animals with different heifers that can deliver one to two years of enhanced economic performance in that position. Subsequently, these replacements have the potential to evolve into highly profitable, high-producing multi-lactation cows. 

As herds improve, there is a trend towards narrowing the production variation within lactations. Genetic and breeding strategies play a vital role in this trend by selecting desirable traits and minimizing the entry of poor-performing animals into the herd. Strategic choices, such as utilizing sexed semen and beef semen, contribute to raising the average production performance in the first lactation and reducing variability within the herd. 

Culling strategies should not be solely dictated by the number of available heifers for replacement. With advancements like sexed semen, herds have ended up raising excess heifers, leading to unnecessarily high cull rates. Striking a balance between economic considerations and herd health is essential to optimize culling decisions. A well-thought-out culling strategy not only benefits the economics of the operation but also enhances animal welfare and public perception. 

To maintain a herd of highly productive and healthy cows for multiple lactations, three key focal points should guide decision making: 

  1. Reduce involuntary culling and instances where biological factors force animals to leave the herd, benefiting the cows, the farm's well-being, and public perception. 

  2. Evaluate the economic opportunities by removing the least economical cows from the herd, enhancing overall profitability and environmental responsibility. 

  3. Ensure that your heifer inventory can support your decisions by maintaining a surplus of heifers to accommodate an additional 5% to 10% culling based on your goals. 

Each cow represents a micro-business opportunity, offering insights into their performance with each lactation. By making informed and targeted culling decisions, we can enhance the welfare, health, and productivity of the herd.

Resources

De Vries A. Symposium review: Why revisit dairy cattle productive lifespan? J Dairy Sci. 2020 Apr;103(4):3838-3845. doi: 10.3168/jds.2019-17361 

De Vries A. LOGISTICS AND MATING DECISIONS FOR SUSTAINING THE OPTIMAL ANNUAL DAIRY COW REPLACEMENT RATE 2022 Dairy Cattle Reproduction Council Conference 

Nguyen, B. T., Briggs, K. R., Eicker, S., Overton, M., & Nydam, D. V. (2023). Herd turnover rate reexamined: a tool for improving profitability, welfare, and sustainability. American Journal of Veterinary Research, 84(1), ajvr.22.10.0177. Retrieved Apr 4, 2024, from https://doi.org/10.2460/ajvr.22.10.0177