Understanding Sex Link and Autosex Chickens: What’s the Difference?

The terms “sex link” and “autosex” are commonly used in poultry breeding, referring to chicken chicks whose gender can be identified immediately upon hatching. While these terms may sound similar, they denote distinct breeding practices and characteristics. This article aims to elucidate the differences between sex link and autosex chickens, ensuring better understanding for poultry enthusiasts and breeders alike.

Why Knowing About Sex Linkage Matters

Traditionally, determining the sex of baby chicks has relied on a specialized technique known as vent sexing. This method requires meticulous attention and often involves trained professionals, which can lead to potential errors. Both sex link and autosex chickens, however, exhibit physical characteristics that make it easy to identify their gender without invasive procedures.

What Are Sex Link Chickens?

Sex link chickens derive their name from specific gene interactions, particularly dominant and recessive traits located on the sex chromosomes of their parents. This results in variations such as down color or the length of wing feathers, which become apparent at hatching.

For instance, a common example is the Red Sex Link. When a Rhode Island Red rooster is mated with a Delaware hen, the resulting chicks display distinct colors: female chicks tend to be red, while male chicks are yellow. In contrast, reversing the parental breeds does not yield sex-linked offspring, as all chicks would exhibit the Delaware feather pattern.

Understanding Autosex Chickens

Autosex chickens differ from sex link hybrids, as they include purebred breeds wherein the physical traits at hatch help identify the gender. A prime example is the barred Plymouth Rock. Chicks of this breed present as black with white spots; however, the cockerels display lighter hues and irregular head spots, while pullets appear darker with rounder, more compact spots. This visual differentiation makes sexing less straightforward compared to hybrids but still viable.

Notable Examples of Autosex Chickens

During the 1930s, many autosex breeds emerged in response to the need for clear gender identification in chicks. For example, breeders in Cambridge, England, developed these breeds primarily from banned Plymouth Rock crosses.

One such breed, the cream Legbar, showcases a combination of barred Rock and Leghorn genetics. At hatch, cockerels are lighter than pullets. Unfortunately, several early British autosex breeds are either rare or extinct today.

The German Bielefelder is another notable example, characterized by its barred Plymouth Rock ancestry. Pullets possess distinctive dark brown coloring with chipmunk stripes, while cockerels display lighter brown hues and a distinct white head patch.

In the U.S., the California Gray, a result of crossing barred Rocks with white Leghorns, is primarily recognized for its utility in producing the sex-linked California White, wherein only pullets show head spots amidst yellow chicks with black body spots.

Key Differences to Remember

A major distinction between sex link and autosex chickens is reproduction consistency. Sex link hybrids do not perpetuate their specific traits, meaning they do not breed true. Conversely, autosex breeds consistently produce offspring that mirror their purebred parents, providing reliable genetics for breeders.

Further Reading

For those interested in delving deeper into the world of poultry, consider exploring these links:

• 4 Outstanding Dual Purpose Sex Link Hybrid Chickens
• Sex Link Chickens from Cackle Hatchery®
• 22 Autosex Breeds of Chickens and Geese

For more information on these topics, visit The Cackle Hatchery.