Horns are a characteristic feature of many animals, including goats, antelope, sheep, and cattle. Male sheep, known as rams, are particularly known for their large, curled horns that are used for fighting with other rams and defending their flock.
If you’re short on time, here’s a quick answer to your question: Yes, rams do shed their horns every year, usually in late fall or early winter after the mating season ends.
In this approximately 3000 word article, we’ll take an in-depth look at ram’s horns, explaining what horns are made of, how and when they grow, how rams use them, and the yearly cycle of shedding and regrowing their horns.
What Are Ram Horns Made Of?
Keratin Composition
Ram horns are composed of keratin, the same protein that makes up hair, wool, hooves, feathers, nails, and claws in mammals and birds. Keratin is characterized by its high levels of sulfur-containing amino acids, namely cysteine, which allows it to form strong disulfide bonds between polypeptide strands.
These bonds give keratin considerable rigidity and hardness, making it ideal for the development of structures like horns. In fact, horns are essentially solid masses of keratin fibers cemented together into a cone shape around a bony core.
| Keratin protein | 90% |
| Water | 8% |
| Lipids and minerals | 2% |
The keratin in ram horns is produced by specialized epidermal cells called keratinocytes within the horn bud on the animal’s head. These cells aggregate into hardened sheets and fibers that grow out into the horn shape.
The high cysteine content allows extensive disulfide bond formation for strength and rigidity.
Horn Cores and Sheaths
Mature ram horns have two morphologically distinct components – the bony horn core and the keratinous horn sheath:
- The horn core forms first around the horn bud on the young ram’s head. It originates from thickened bone in the frontal skull region. The horn core remains covered in vascular skin that supplies blood to the growing horn tissues.
- The keratinous sheath then begins growing around the horn core, completely enclosing it over time. This sheath makes up the visible horn structure and continues to grow throughout the ram’s life.
In most sheep breeds, the horn cores remain small vestiges that don’t contribute significantly to horn size. For example, one study found that the keratin sheath constituted ~99% of horn weight in Merino rams (DeBuse et al. 2013).
However, some breeds have larger horn cores that reinforce overall horn strength.
Both horn components are living tissues that can be damaged or feel pain signals. However, the keratin sheath is effectively “dead” protein that lacks nerves or blood flow. Only the softer skin under the base of the sheath is innervated and vascularized (Lomax and Windsor 2013).
The Growth Process of Ram Horns
When Horn Growth Begins
Ram horns begin growing from birth. Newborn lambs are born with tiny horn buds under the skin of their foreheads. These horn buds are made of bone covered with a sheath of keratin, the same material that makes up human fingernails.
As the lamb grows, the bony core of the horn buds extends upward and outward, pushing through the skin by around 2-3 weeks of age.
Factors Influencing Horn Size and Shape
Several factors influence the ultimate size, shape, and curvature of a ram’s horns:
- Genetics – Some sheep breeds are known for their impressive horns, while others have smaller horns.
- Nutrition – Well-fed rams tend to grow larger horns over their lifetime.
- Age – Horns grow continuously as the ram ages. Older rams generally have the largest set of horns.
- Testosterone – Castrated rams (wethers) typically have thinner, slower-growing horns compared to intact males.
- Physical damage – Injuries, frostbite, etc. can affect normal horn development.
The corkscrew shape of most ram’s horns is believed to result from genetic and testosterone influences. Interestingly, even if one horn gets broken or damaged, the other horn still tends to grow in a corkscrew curve!
Annual Growth Cycle
A ram’s horns go through an annual growth cycle. The period of fastest horn growth is from spring to mid-summer (roughly March through July in the Northern Hemisphere). This is when vegetation quality is highest, and circulating testosterone levels also peak leading up to the fall breeding season.
The rate of growth slows through autumn and winter when food is scarcer and days are shorter.
During each summer growing phase, the keratin sheath surrounding the bony core thickens and extends outward. Then in winter this sheath is worn down from rubbing behaviors, exposure, and other factors. Over time, growth exceeds wear leading to continuously larger horns each year.
By examining cross-sections of the horns, the annual growth layers resemble the rings inside a tree!
How Rams Use Their Horns
Establishing Dominance
Ram horns serve an important purpose in establishing hierarchy and dominance within a flock. The larger and more impressive the horns, the higher status a ram holds. Rams will butt heads and wrestle to determine who is the lead ram of the flock.
The dominant ram gets priority access to food, water, and mating rights with the ewes. Rams with smaller horns must defer to those above them in status. Horns are a symbol of power and authority for rams.
Fighting for Mating Rights
During breeding season, rams fiercely compete with each other for the right to mate with ewes. They engage in battles known as “ramming” where they violently clash horns and foreheads. These fights establish which ram is fit to pass on his genes.
The clashes are dangerous and can result in broken horns, head injuries, and even death in some cases. However, the breeding privileges awarded to the victor are worth the risks. The mature rams with the largest, most intimidating horns typically dominate these battles and win mating privileges with the most ewes in the flock.
Defending the Flock
In addition to establishing hierarchy, ram horns also serve the purpose of defending the flock from predators. Rams are naturally protective of the ewes and lambs. When a predator threatens the flock, the lead ram will confront the intruder first, using its imposing horns as weapons.
The ram lowers its head, charges, and powerfully strikes out with its horns to deter or injure the predator. Even against large predators like wolves or coyotes, the ram’s size, strength, and sharp horns can be an effective first line of defense.
The ram’s status, mates, and offspring depend on its ability to protect the flock.
The Annual Cycle of Shedding and Regrowing Horns
When Shedding Occurs
Rams typically shed their horns annually, beginning the process in the fall or early winter. The exact timing varies depending on factors like nutrition, health status, and breed. On average, shedding occurs from November through January in the northern hemisphere.Most rams lose their old horns by the end of February.
Hormonal Changes Preceding Shedding
Horn shedding is triggered by changes in hormonal levels within the ram’s body. As daylight hours decrease in the fall, the pineal gland begins producing higher levels of melatonin. This hormone inhibits testosterone production, which causes changes to horn tissue that lead to shedding.
The horns essentially loosen from their cores over a period of weeks as the hormone levels shift.
The Regrowth Process
Shortly after shedding their old horns, rams will begin regrowing a new set. The regrowth process is kickstarted by increasing daylight in late winter and early spring. This cues the pituitary gland to produce more gonadotropins, which in turn stimulate testosterone production.
The testosterone causes new horn tissue to grow rapidly over the permanent bony cores of the horns.
It takes around 4-5 months for rams to fully regrow their horns. Breed, genetics, nutrition, and age all impact the rate of growth. Mature rams typically regrow larger horns each cycle as they age. Proper nutrition is essential to support optimal horn development.
Nutrition Requirements for Regrowth
Several key nutrients are vital for rams regrowing horns after shedding:
- Protein – supplies amino acids to build new horn tissue
- Calcium and phosphorus – supports bone growth of the inner horn cores
- Copper and zinc – involved in testosterone production to stimulate regrowth
- Vitamin A – aids in epithelial tissue formation
Rams should ideally receive a diet with at least 16% protein, proper calcium to phosphorus ratios, and balanced mineral supplementation at the time of regrowth. Good overall nutrition reduces chances of abnormalities in the new horns. Always provide free-choice hay and fresh water as well.
Other Key Facts About Ram Horns
Differences Between Wild and Domesticated Rams
There are notable differences in the horns of wild and domesticated rams. Wild rams generally have larger, more curved horns compared to domesticated breeds. This is likely due to selective breeding practices over time that have altered horn shape and size.
Wild rams require their horns for defense, competition and mating rituals – their survival depends on having large, strong horns. Domesticated rams live in more controlled environments and do not need horns as much for survival.
Some domestic breeds like Merinos have been selectively bred to have smaller horns or even no horns at all.
Selective Breeding for Horn Size
Sheep farmers and breeders have long practiced selective breeding to develop rams with desired horn sizes and shapes. Breeds like the Merino are specifically bred to have smaller horns to prevent wool fiber damage. Other breeds are selected for large, imposing horns such as the Jacob sheep.
The size, curvature, ridges and other horn features are carefully evaluated when breeding rams. Larger horns in breeds like Mouflon rams are seen as more attractive for trophy hunting. For commercial meat production, breeds with smaller, easier to manage horns are preferred.
Selective breeding over many generations has gradually altered horn size from the original wild Rupicapra rupicapra from which domestic sheep descended.
Dehorning Practices
While selective breeding reduces horn size in some breeds, dehorning is still commonly practiced for safety and management reasons. Farmers often dehorn young rams to prevent injury during transport or in close quarters.
Dehorning methods include physical removal, chemical treatments, heat cauterization and genetic modification. While pain management practices are improving, dehorning is still controversial regarding animal welfare. However, safety and economic concerns often lead farmers to continue the practice.
There are ongoing efforts to breed “polled” (hornless) genetics into sheep flocks to reduce the need for dehorning. However, eliminating horns through cross-breeding can take many generations. In the meantime, dehorning remains widespread on both small and large sheep farms globally.
Conclusion
In summary, the horns of rams and other horned animals are complex structures that grow in regular cycles throughout the year. The size, shape and timing of ram horns are influenced by genetics, nutrition and testosterone levels.
Rams rely on their horns for establishing social dominance, competing for mates, and protecting their flock. While horns are shed annually, they regrow quickly to serve their essential functions again.
Understanding the details of ram horn growth and shedding can help farmers and ranchers provide optimal care for their flocks.
