Rabbit farming part 9: Rabbit hair production

When discussing textiles, the term “angora” by itself always and exclusively refers to the hair of Angora rabbits.

The hair of Angora rabbits is one of five keratinic textile fibres of animal origin that have significant economic value. Sheep’s wool, at over 1,3 million metric tonnes annually, is by far the most important fibre. The other four, mohair, angora, cashmere, and alpaca, each produce between 5 000 and 30 000 tonnes annually, and their unique fineness, lustre, and feel make them ideal for use in high-end luxury goods. In the textile industry, angora is ranked among the “noble” fibres.

Characteristics of wool textiles

Length – Angora hair is unusually long due to a prolonged active phase of the hair follicle cycle. It grows for 14 weeks, whereas ordinary (short) rabbit hair grows for only five weeks. Angora rabbits have a recessive gene that is responsible for the long hair.

Aside from its length, the coat contains the three classic rabbit hair types.

guide hairs: longest (10 to 11 cm), roughest; they guide the coat;
guard hairs (“barbes”): shorter than guide hairs (8 cm); their rough points lie on the coat and seal it (covering hair); four per guide hair;
down: shortest hair (6 cm), rounded point, barely visible, very fine body (14 µ). Thermic insulation undercoat has 60 guide hairs. Angora hair’s length allows thread cohesion, giving it textile value.

Because of the slight relief in the cuticle, rabbit hair has a low friction coefficient. This results in softness but also slipping. Angora hair is twisted and stays in the thread because of its length. Using ordinary rabbit hair to replace angora produces low-quality threads that spread everywhere. This is a fraudulent process that harms the Angora industry.

Hair characteristics

Although Angora rabbits can be found in a wide range of colours, only the albino variety is currently bred for commercial use.

The animal’s pure white fur is ideal for the process of dying. In many countries, breeders of Angora rabbits of various colours raise the animals so that the breeders can make undyed artisanal fabrics with subtle colour patterns.

All of the hairs are medullated, making them less dense than wool (1,1 versus 1,3) while still providing excellent warmth. They share every quality of keratin, including insulating properties, a high water-holding capacity, and a favourable reaction to dye.

Fur production terms

Curing: tanning skins with hair.
Shearing: separating implanted hair from skin.
Knife marks: skinner’s knife slits or perforations.
Skinning: removing animal skin from a carcass.
Brushing: gently repositioning hair during the curing process.
Pellicle: thin collagenous film on flesh.

Fur: rabbit hair and skin.
Glossing: dyeing cured fur.
Moulting: hair follicle reactivation. Former hair is hydrolysed to make way for new hair.
Moulting zone: area of skin with active hair follicles. Dark blue patches on the pelt’s skin. Slaughter interrupts hair growth, making it easy to shed or shorten.

Hair collection

The hair is collected every 90 to 100 days, when the follicles are in the resting stage and before the hair starts falling out and causes felting that reduces value. The hair is cut with scissors, or electric or manual shears, or collected by depilation.

Depilation is the method of plucking the loose hair, but using shear products make shaving rabbits faster, easier, and less stressful.

French-type Angora rabbit hair is better collected by depilation than by shearing or scissors. Their genotypes differ in how quickly hair follicle growth resumes after collection.

Habitat

Angoras really do not like heat over 30 °C. Low temperatures (below 10 °C) are a problem after hair collection. Open-air production has long been the norm, but denuded rabbits must be protected, especially when depilation is used. Breeders use two-stage depilation, leaving a “back” that is later removed; body-coat, warmers, postdepilation boxes, et cetera.

Feeding Angoras

Angora rabbits have specific dietary needs that differ from those of meat rabbits. When an Angora is at the height of its productive capabilities, it resembles a normal adult rabbit. They will reach their full size and can only reproduce with a select few animals at a time.

However, they must produce more than 2 kilogrammes of dry proteins per year, including more than 1 kilogramme of keratin (hair) and the same quantity from the internal sheath of the hair follicle. This is roughly the same as having 7 or 8 kilogrammes of lean muscle mass.

Adult Angoras tend to die in the days following hair collection because they have trouble regulating their body temperature. They are much more likely to get sick from a cold or the flu (pasteurella, coryza, et cetera). Therefore, the breeder needs to be vigilant about maintaining a clean environment (frequent litter renewal, cleaning, disinfecting).

Because first-year Angora output is noticeably lower, 650 g compared to 1 kg, replacing working females with young does reduce average production levels. The average yearly renewal rate is between 25 and 35%.

Non-genetic hair growth factors

The interval between collections is the most important, based on weight. This effect is attenuated when considering annual output.

Shearing reduces adult doe productivity by 30% in the (depilated) French strain. For French strains, the first four hair collections represent 11%, 60%, 81%, and 93% of adult production. It seems that the German strain is more advanced, as the fourth and even the third collection show that it has reached its full potential.

Male French rabbits have 20% less hair than females. Literature reports a difference of 0 to 15% for the German strain, with most citing 10% less for male rabbits. Live weight is irrelevant, except during growth, but should correlate with collection number (first, second, et cetera).

Winter collections are always 4 to 30% heavier than summer collections. Higher strain productivity reduces the seasonal effect.

Other factors like birth season have been studied, but more data is needed to confirm these findings. Diet (deficiencies), temperature, and comfort all affect hair growth.

Non-genetic hair production factors

Length, down fineness, guard-hair diameter, fur structure, and composition are Angora hair quality parameters. Last, woolly fur differs from guardhaired fur. The latter include those with over 70% full guard hairs (that is pointed ends) and less than 1% of fibre shorter than 15 mm, according to the 1992 Corvallis Convention.

A quality parameter is felting or dirty fur. The time between haircuts affects hair length. The collection method distinguishes guard hair from woolly hair. At least for the first harvest, the number of collections is important for all rabbit strains, and for the second and third collections in French strains, where young rabbits still produce woolly fur after depilation.

The sex factor is weaker in the German strain than in the French strain, but males tend to feel it more. Live weight and season have less effect on adults; the length ratio of underfur to guard hair is less in summer than in winter: 55% in summer versus 65% in winter.

The information provided in this article is credited to:

Lebas, F., Coudert, P., de Rochambeau, H. & Thébault, R. (1997). The rabbit – Husbandry, health, and production. ISBN 92-5-103441-9. Available at: https://www.researchgate.net/publication/38977233_The_Rabbit_Husbandry_Health_and_Production