Genetics

Weekly genetics review: Functionality – be clear on what you are selecting for

Genetics editor Alastair Rayner 08/10/2024

THE term, functionality, is widely used in the beef industry, often with varied interpretations depending on the context.

Functionality encompasses a broad range of traits that are crucial to breeding and production. While many producers may understand the general idea of functionality, the term’s use can sometimes blur the focus, leading to confusion about specific breeding objectives.

To effectively improve a herd’s productivity, it is essential to be clear about what ‘functionality’ means and which traits contribute to it.

The beef industry is rich with descriptive terms used to characterise animals and production systems. These terms, sometimes but not always developed in the context of livestock shows, are sometimes applied in everyday breeding and production discussions.

However, many of these descriptions are subjective and encompass multiple traits. For instance, terms like ‘broodiness’ of females and ‘sirey outlook’ are often heard in the show ring but can lack precision when applied to real-world breeding programs:

  • Broodiness: While this term originates in avian behaviour (particularly poultry), where it refers to a female’s instinct to sit on eggs and incubate them, in cattle it is used to describe a set of maternal traits. These traits might include structural soundness, udder quality, and calving ability, which together ensure a cow can successfully raise a calf. While producers might understand the broad intention behind the term ‘broodiness,’ it doesn’t provide a clear-cut set of criteria for selecting superior breeding females.
  • Sirey Outlook: This term describes a bull that looks and acts the part of a breeding sire. It typically refers to traits like structural soundness, size, and muscle development, masculinity in head features, as well as the bull’s overall physical presence and how it carries itself. Again, while producers might understand what is implied by ‘sirey outlook,’ the term wraps multiple traits into a subjective description, making it difficult to use effectively in selection without a more objective approach.

Both terms provide a general understanding of animal traits, but they lack the precision needed to guide a breeding program toward specific, measurable goals.

Successful breeding programs require clarity and specificity when selecting for certain traits. Genetic progress is achieved when both sires and dams are selected for traits that suit the herd’s specific needs. This selection must be rigorous and based on objective measures rather than subjective, generalised terms.

Genetic improvement a gradual process

While some early gains can be made by selecting superior individuals and culling low performers, true progress requires consistent focus on the traits that will drive long-term genetic improvement.

Genetic improvement is a gradual process, but it can be accelerated by capturing the variation that exists within a herd. In any population, there will be individuals who excel in a combination of desirable traits, while others perform closer to average or fall behind.

Producers often cull the lowest-performing animals based on basic criteria, such as fertility or temperament, but sometimes this selection process stops there. By treating the remaining herd as a uniform group, producers miss out on the opportunity to identify and capitalise on the best-performing animals. As a result, genetic progress is slowed.

One common pitfall in cattle breeding is the use of broad, subjective terms like “functional females.” While this term generally has positive connotations, its meaning can vary widely. Without a clear understanding of the specific traits included in the term, it becomes difficult to use “functionality” as a selection criterion. To accelerate genetic improvement, producers must break down broad terms like “functionality” into specific, measurable traits.

By dissecting what is meant by ‘functional females,’ producers can focus on the individual traits that contribute to the overall functionality of their herd. Once these traits are identified, they can be measured and selected for, leading to more rapid progress. Instead of allowing high-performing individuals to blend into the average herd, producers can identify and promote these animals, ensuring that their superior traits are passed on to future generations.

The traits that are typically included under the umbrella of “functionality” often relate to herd fertility and productivity. These traits include:

  • Calving Ease: The ability to calve unassisted is a critical trait for functional females. Cows that consistently give birth without complications are more likely to remain productive members of the herd.
  • Reproductive Efficiency: Cows that maintain a twelve-month calving interval and rear a healthy calf to weaning are key to herd productivity. These traits are the foundation of reproductive efficiency.
  • Milk Production and Weaning Weights: The ability to produce enough milk to rear a strong, healthy calf is another trait that defines functionality. Producers can target this trait by selecting sires with high accuracy Estimated Breeding Values (EBVs) for milk production and 200-day weight.
  • Mature Cow Size and Growth: The size and maturity pattern of females are also important components of functionality. For instance, selecting cows that are best suited to the environment in terms of mature weight and growth pattern can ensure that they remain productive over a longer period.

Producers can use objective measurements, such as EBVs for Calving Ease, Days to Calving, Birth Weight, Milk, and 200-day weight, to select for these traits. In doing so, they can improve herd fertility and productivity while ensuring that their cattle are suited to the production environment.

The term ‘functional female’ is often used positively, but it is crucial for producers to understand exactly what it means and how to measure the traits that contribute to functionality. If not properly understood, vague terms like this can lead to assumptions that hinder genetic progress.

It’s important for producers to break down subjective descriptions into specific, measurable traits that align with the goals of their breeding programs. Only by doing this can they achieve meaningful progress in terms of both productivity and profitability.

To ensure long-term success, producers should consistently evaluate their breeding objectives, focus on measurable traits, and avoid relying on generalized terms. By doing so, they can create a more productive and profitable herd that meets the needs of their specific production environment.

 

Alastair Rayner is the General Manager of Extension & Operations with Cibo Labs and Principal of RaynerAg.  Alastair has over 28 years’ experience advising beef producers & graziers across Australia.   He can be contacted here or through his website www.raynerag.com.au

 

 

 

 

 

 

 

 

 

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