Fiber Production Basics In Goats

By Kathy Blackett, owner of Snokist Farm Pygmy & Pygora Goats

Goat fiber or hair is produced by rapidly dividing cells in the bulb at the base of the hair follicle. The hair follicles of goats are grouped in clusters. Within these clusters are primary follicles and secondary follicles. Primary follicles produce guard hairs, while secondary follicles produce undercoat or down. Secondary follicles in the Angora goat have been modified to produce mohair. Cashmere as well, is produced by secondary follicles.

The Pygora goat has been given the genetic capacity to produce both mohair and cashmere from its secondary hair follicles. This explains the three different fiber types possible: the "A" type which is pure mohair; the "B" type which is a fiber with combined traits from both mohair and cashmere; and the "C" type which is pure cashmere.

The prenatal development of secondary hair follicles in the Angora occurs during the fourth month of gestation and continues through the first month after birth. For Cashmere goats, maximum secondary follicle development is achieved by 20 weeks of age. This development can be affected by nutrition, so care should be taken to insure correct nutrition of the doe in late pregnancy and through lactation. Poor nutrition during these times will effect the goat kids ability to produce fiber later in life.

The hair growth has an active phase (anagen), and a resting phase (telogen). Growth from the bulb is continuous during the active phase. The active phase is followed by the resting phase, and then by molting. After the cycle is complete and growth resumes in the next cycle of growth, the new hair produced by the follicle helps to push out the old hair. This causes natural shedding of the hair.

Fiber density in the fleece is determined by hair follicle density in the skin. This density is controlled by both genetics and nutrition. Fiber density increases with age and weight. Under-nutrition will result in a reduction of fiber diameter, but it also reduces body growth and the amount of fiber produced. Intentionally depriving fiber goats a higher percentage of protein in their diet is actually false economy and will cause negative effects on health, reproduction, feed conversion, and fiber yield.

If we look at fiber density in a theoretical manner, follicle production ended in early life. There is only so much room on the skin surface, so the more follicles produced at this time, the smaller they will be, and the finer the fiber will be over the life of the goat. When a goat is overweight, the follicles that are present in the skin are caused to stretch to a larger size. Because the fiber produced from these "stretched" follicles fills the size of the follicle, the fiber produced will be of a greater diameter. A goat in thrifty, but healthy condition will produce finer fibers. Also, breeding does after the active phase of fiber production has ended its cycle in the fall will help insure she produces the finest fiber she is capable of producing, even when her skin is stretched out later during pregnancy.

Age may also cause skin to sag, which in turn would cause the follicles to become enlarged. Again, if we pay close attention to nutrition during the developmental stage of follicle production, we can have a direct effect on the fiber diameter produced later in life. Feed additives that help the skin to stay in healthy, supple condition may reduce this tendency and help goats to produce finer fibers for longer periods of time. We could also assume that proper exercise would help invigorate the skin and keep it in younger condition. External parasite control is a must in keeping follicles in healthy, productive condition.

We can control the genetic end of the fiber production scale by selection of breeding stock through fiber testing. Once we know what quality fiber our goats are able to produce, we can help them to reach their genetic potential with proper management.