8. Production of rabbit skins and angora wool
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Organizing a rabbitry
The objective in raising rabbits is meat production. The exceptions are rabbits raised for their fur only-a rare exception this (only the Rex rabbit at present, and in very small numbers)-and the Angora rabbit for textile wool.
The outcome is that the rabbit pelt (as with all slaughter animals) is a byproduct, imposing no special constraints on meat production methods. But wool is the main target of Angora rabbit production and the need to produce a quality fur has led Angora breeders to develop methods quite different from those used in meat rabbit production.
These two production systems should therefore be dealt with separately because of their different natures, destinations, markets and production techniques. There is only one point they have in common: hair shorn from lower-grade skins that cannot be used in fur manufacture is partly used by the textile industry.
Rabbit fur production is not comparable with the production of other fur species. Mink, which tops the list of species bred essentially for their fur, supplies a world total of about 25 million pelts a year. In France alone annual rabbit skin production tops the 70 million mark. But mink is bred for its fur and rabbits for meat, so rabbit fur is just a byproduct to which breeders give scant attention.
Intensive meat rabbit production techniques in Europe are usually incompatible with production standards for quality fur pelts. In fact, the raw skin represents only a small percentage of the value of the living animal. So more and more frequently rabbits are slaughtered at an age or time of year when their coats have not fully developed. This is usually at 10-12 weeks when they still have an infant coat or are beginning the sub-adult moult. These thin, unstable coats are not suitable for furs.
The only season when the adult coat is stable and homogeneous is winter. This is true of any animal over 5 months of age. The rest of the year there are always moult areas of greater or lesser size, so the coat is uneven and the hair is not firmly attached to the skin. Some summer coats can be homogeneous, especially those of rabbits that have completed the sub-adult moult, but the rabbits must be at least 5 months old. The summer coat is also thinner than the winter coat.
This rather inflexible growth cycle and seasonal changes in the coat create the problem of simultaneous fur and meat production. Fur can therefore only constitute a byproduct, especially in intensive production. However, no research has been done on moulting patterns in hot climates; the figures given here only really apply to temperate regions. In extensive production, rabbits are slaughtered at 4-6 months, and this is the situation in many tropical countries. So quality skins could be produced in the tropics assuming the proper skinning and preserving techniques were used.
SORTING AND GRADING PELTS
In an unsorted batch of rabbit skins valuable pelts can be found side by side with useless waste, so sorting and grading should be done as early as possible. Sorting is the first operation and determines the future use of the skin. Skins are sorted into 3 grades.
1: Pelts for dressing (the term "dressing" instead of "tanning" is used for fur). These are the best skins, with regular shape, intact, homogeneous, dense, a well-formed coat, a flawless skin. Their price may be 20 times that of ordinary-quality skins.
2: Pelts for shorn hair. These usually lack the proper shape or are not homogeneous enough for fur products. The hair, however, is sufficiently long and healthy. It is therefore machine shorn and used for textiles or felting (though the millinery trade is declining in many countries). The skin is cut into fine strips (vermicelli) and made into glue (another declining industry) or fertilizer. This technique allows much of the pelt to be recycled.
3: Waste, unusable except for fertilizer (the hair is gnawed, cut, soiled, sweaty, parasite-ridden). These skins push up the costs of labour, processing and transport.
In France, one of the foremost rabbit producing countries, the proportion of pelts suitable for dressing is less than a half of those collected.
The figure differs from one author to another, which is not surprising in view of the difficulty in getting exact data on this product.
The customer buys the skins in commercial lots (from 0.5 to 5 tonnes) of matching quality. The following grading system is used in France (and also in many other countries because of the number of French traders in the fur market). For pelts for shorn hair: rejects-hair weight 10-18 percent of the dry pelt weight; ordinary-hair weight more than 18 percent of dry pelt weight; good quality, with guard hair removed-for glovemaking. For fur pelts:
Grading is more complex for fur pelts, as colour, size and quality are all considered. The colours are white, range of grey, range of red (nankin), mixed and black.
Size is assessed by the weight per 100 dry pelts:
entre-deux: 12-13 kg/100 pelts (100-140 g per pelt);
cage: 13-20 kg/100 pelts (150-210 g per pelt);
heavy: 26-40 kg/100 pelts (250-350 g per pelt).
The gap between grades and the difference between weight per IOU pelts and unit weight stem from fluctuations in assessment.
Quality assessment covers the integrity of the pelt (proper cut, good fleshing, no knife marks or holes from skinning) and its structure (height of guard hair, compactness and height of downy undercoat and the homogeneity of the coat):
pelts 4: poorest;
pelts 3, 2 bis: medium;
pelts 2 and 1: best.
This classification, which at first sight looks complex, is in actual fact relatively simple: traders and clients know exactly what merchandise is in question when they speak of a °Cage 2 grey" or an "entre-deux 4 nankin".
The system, with slight variations, is the same in every country, understandably so considering rabbit pelts are an international trade item. In the United States, where rabbit production is not widespread and is undertaken by amateurs, US Department of Agriculture grades are (US Dept Agric, 1959):
Firsts and seconds include 5 colours: white (price sometimes double that of colours as they can be dyed); red; blue; chinchilla; mixed.
Sorting and grading clearly show that it is in the interest of the breeder and the general economy of the country to produce the highest possible proportion of quality pelts or at least reduce the proportion of those which are unusable. It is also important to be able to constitute homogeneous commercial lots. This means that if production is low in a region the range of colours should be limited. The choice is not simple, given the ups and downs of fashion. The wisest choice would normally be white, as it generally commands a good price and once dyed can easily follow colour fashion trends. However, this is not the best advice at present' with longhaired fur in vogue and dyeing virtually in disuse.
THE PRODUCTION OF QUALITY PELTS
The main barrier to quality pelt production is slaughter age: the pelt must be big enough, and the whole coat mature. The crucial times are moulting-juvenile moults for growing rabbits and seasonal moults for adults.
The seasonal moults in adults are ruled by seasonal photoperiodicity and occur in spring and autumn. The spring moults are spectacular, with visible loss of winter hair, but they are slow and irregular and rarely give an entirely stable coat in summer. This summer coat, thin and short, is not among the most prized-it weighs only 60 g. The autumn moult on the other hand reactivates all the hair follicles in a relatively short time. It gives longer hairs and above all multiplies the secondary hair follicles which produce a part of the undercoat. The winter coat, which remains stable for several months, weighs approximately 90 g. It is this coat which is the most highly prized of all, if not the only one used. In addition, the network of collagen fibres of the derma is contracted, and produces a finer and stronger skin.
It is obviously preferable in a temperate climate to slaughter the animal at the onset of winter, as soon as the coat is mature, to ensure the least possible deterioration of the hair. Unfortunately no detailed study has been made in tropical or equatorial climates.
There are 3 types of juvenile coat: that of the newborn rabbit, infant coats, and sub-adult coats. The first two are unusable because they are too small. The coat of the newborn rabbit stops growing when the animal reaches 0.4 kg (for an average size breed); it weighs only 8-10 g. The infant coat is mature at around 9 weeks and its weight depends on the rabbit's weight, since the number of hair follicles in development depends on the size of the skin area of the growing animal. If a rabbit weighs 0.5 kg at 9 weeks it carries 15 g of hair, against 30 g for a rabbit weighing 1.1 kg. The coat is thus still light in weight and the hair is fine.
The sub-adult coat becomes more interesting but the moult which produces it is long (4-5 weeks) and only begins when the rabbit reaches 1.71.9 kg. It matures at the earliest at 4 to 5 months, usually after 5 months. The weight of the coat, and hence the length of the hair and its density, also depends on the season in which the hair develops: 40 g in summer, 60 g in autumn or in winter, which is acceptable. The sub-adult coat is therefore the first coat that could provide a fur.
It is very difficult to obtain pelts for fur in intensive production systems (slaughter at 11 weeks). However, a breeder might attempt to produce acceptable pelts for shorn hair by using simple measures (animal housing, precautions at slaughter and skinning).
It is not impossible to produce pelts for fur in a rational extensive production system (an extensive system in which production techniques are strictly adhered to, especially with regard to hygiene, habitat and feeding). In fact, with a low investment, not forcing the animals' growth and using an economical but balanced feed regime, it should be possible to slaughter the animals at around 5 months.
Sub-adult and adult moults are ruled by seasonal photoperiodicity. They can therefore be induced by artificial lighting, but this calls for sophisticated installations (windowless housing) and the technique is complex (interference with reproduction). At present, natural photoperiodicity seems to offer the greatest security for the production of quality pelts, which argues in favour of rational, extensive production.
Temperature does not influence moults, but it does seem to affect the structure of the coat: a greater number of downy hairs and longer hair in cold zones, and a shorter, thinner coat in hot zones. As a consequence, cold or temperate countries are more likely to provide pelts for fur production.
Rearing rabbits in colonies leads to fighting and possibly trichophagy (the rabbits eat one another's hair for lack of roughage in the diet). Individual cage rearing, at least during the month preceding slaughter, is to be preferred. The cage with straw litter, as will be seen with the
Angora rabbit, gives a completely defect-free and clean coat, but individual mesh cages can also give good results. In this area too, extensive production is more likely to provide pelts for fur production.
A wholesome, balanced diet is required-the question is whether to aim at a rapid growth, or a slightly moderated growth rate using economical rations from the farm's own produce. For fur production, slaughter should be delayed to 5 months, or 41/2 months at the earliest, and this also argues in favour of rational extensive production.
Any physiological imbalance or pathological disorder has immediate repercussions on the coat, even if it has reached maturity. It becomes dull and unkempt, the secretion of the sebaceous glands is disturbed and the rabbit neglects its grooming. A skin collected in this condition will never make a good fur. Normal hygienic procedures, valid whatever the production system, also favour the production of a quality pelt and help to avoid diseases which specifically affect the skin. This will be one of the most difficult problems for developing countries.
In making this choice there are two factors above all to be considered with relation to grading pelts: colour and size.
Colour is a question of fashion but, as mentioned earlier, white is the most suitable as it is impervious to fashion changes; it can be dyed. It must be remembered that the trader is interested only in lots of 4 or 5 tonnes. Large pelts are the most prized; without going so far as to produce giant rabbits this means that midget breeds should be set aside.
Lastly there is the structure of the coat: it should be homogeneous, with long hair and a thick undercoat well covered with silky guard hair.
THE COLLECTION, PRESERVATION AND STORAGE OF PELTS
Skinning should be carried out in a manner that ensures the largest possible skin surface, which is an important part of its value. The first cut is usually an incision at the hind feet, passing from one thigh to the other. The skin is then pulled off. The skin on the head is of no commercial value so it can be discarded, which facilitates the drying.
This operation should be done with care to avoid mutilation, knife marks, grease (which oxidizes and burns the skin) or bloodstains. All these defects reduce the value of the pelt, especially when the coat is originally of good quality. The sequence of skinning operations is illustrated in Figure 42.
FIGURE 42.-Skinning a rabbit
Rabbit pelts are preserved only by drying. This is a simple operation which can be done anywhere, and costs little (the salt used to preserve the skins of other species can be expensive). Drying should start immediately after the skin has been removed. It must cool off quickly and dry out to prevent the action of enzymes in the derma which attack the hair root and cause the hair to fall. If fresh pelts are left in a pile for even a short time a rapid bacterial fermentation will set in and cause the hair to fall out in patches. Many pelts are lost this way for a lack of elementary care.
The skins are shaped on a frame. They should not be excessively stretched, not should there be any creases. The frame can be a board, a steel wire frame (Figure 43), or even a fairly supple stem with no branches. Straw should not be used as padding as it can deform the pelt.
During drying, air should circulate freely, and the skins should not come into contact with one another. It is out of the question to accelerate drying by exposing the skins to the sun or to hot air, above 50°C the collagen of the derma is altered irreversibly and the skin cannot be processed. They should be dried in the shade in a well-aired place (optimum temperature 18-22°C, 65 percent relative humidity).
FIGURE 43.-Correct way to dry rabbit pelts
The pelts are arranged in piles when they are perfectly dry in a cool airy room, with insecticide (naphthaline) between each layer of skin. It is best to grade the pelts without delay, the grading being more or less elaborate according to the size of the stock in question. At least the different qualities should be separated immediately, and the white skins from the coloured.
Whether the destination of the pelt is fur or hair production, all operations from skinning to storage must be carried out with care and attention. The slightest fault in handling results in a lowering of grade, which is all the more serious when a high-quality skin is involved and all the work carried out previously is lost. The greater the homogeneity and quality of the pelts the more attractive they will be to the trader, which is particularly important at times of market depression.
If it is intended to extend rabbit production in a country for the profitable sale of the pelts, the training required should not be underestimated. It will be needed not only in production, particularly in teaching producers how to recognize the state of maturity, but also in the care needed in skinning the animal and in preserving and storing the pelt. Experience with hides and skins of other species shows the extent of losses due to negligence (in some countries only 1 pelt remains from every 3 animals slaughtered). Perhaps bad habits can more easily be avoided with the introduction of new husbandry methods.
CURING AND GLOSSING
Developing countries are increasingly processing the cattle hides and sheep skins they produce. The first step is to turn out semifinished products, for which the technology is simpler and more uniform, albeit demanding, and for which there is a wider market. Finished leather is a specialized product whose manufacture is far more delicate to undertake as experience and imagination are both essential.
This is why developing countries are holding back their rough pelts to make semifinished products such as wet-blues and hides (India, Pakistan). This system obviously has the advantage of using the local labour available and giving greater value to the exported product.
Is the same development possible for rabbit pelts? This is difficult enough to answer with regard to other fur, which must always be perfect, and even more difficult for rabbit fur, towards which there is some consumer resistance, and because European output, though of medium quality, is so high. On the other hand, shearing the pelt for the hair does not seem to pose any particular problem any more than does the utilization of the remainder of the skin, even if only for fertilizer. There is also the possible manufacture of small objects such as toys with pieces of low-quality fur; however, this is of relatively small economic importance and may involve difficulties with the hygiene regulations of importing countries.
Processing the pelt to the semifinished stage requires a series of operations:
This is a complicated finishing operation, with variations such as shaving or colouring according to the final product required. It calls for much handling, expertise and imagination (mixing of dyes, special effects, etc). These operations are too complex to describe here. However, it is often the furrier who, having chosen his lot of rough furs, decides on the final appearance they will be given. For a coat, 20-30 skins will be needed. The making up of "bodies" (remnants of fur sewn together and sold by length), which is labour intensive and not highly automated, can be done in developing countries or in countries where the labour is less expensive (Greece, the Republic of Korea, and, for mink pelts, Taiwan [Province of China]).
It would be mistaken to assume that the pelt for shorn hair is a negligible product. Depending on quality its value can be very high-80F in France in 1978, againt 300F for an Angora pelt. The fluctuations in value, however, are vertiginous because demand is not constant: a pelt for hair can be worth between 1 and 20F according to the quality and the demand of the moment. This figure is multiplied by 5 to arrive at the price of the hair.
In the matter of textiles, "angora" without any other qualification refers solely to the hair produced by Angora rabbits.
Its ISO (International Organization for Standardization) symbol is WA: W for wool, reserved for noble textile hair, as opposed to H used for ordinary hair. The letter A is for the Angora rabbit, and distinguishes it from the mohair goat, M (the term Angora goat is no longer used). The symbol for mohair is thus WM. The short hair of the ordinary rabbit is designated HK (K = Kaninchen in German).
Angora hair is unusually long owing to the prolongation of the active phase of the hair follicle cycle: the hair grows for approximately 14 weeks? whereas that of the rabbit with ordinary (short) hair grows at the same rate but for only 5 weeks.
Apart from this great length, there is no other modification either in the hair's structure or in the composition of the coat, which contains the 3 classic types of rabbit hair:
It is the length of angora hair which gives it its textile value as it permits cohesion in the thread.
The rabbit's hair is characterized by an extremely low friction coefficient which is due to the very slight relief of the cuticle scales. This results in a particular softness to the touch, but also an exceptional capacity for slipping. This is why the length of angora is important; the hair is twisted and stays in the thread. The use of ordinary rabbit hair to replace angora produces threads of bad quality which spread everywhere: this is a fraudulent process which reflects badly on the angora industry.
Because of its softness angora hair is used for the manufacture of insulating underclothes (keratin). Ten percent angora in a mixture of wool, cotton and synthetic fibres makes an extemely soft fabric, very easy on the skin.
The kemp points and the covering hairs, which are more rigid rise from the fabric, giving it a fluffy appearance which is much prized. Whole angora hairs obtained by depilation are the most suited for this purpose.
Though the Angora rabbit exists in all colours, only the albino strain is produced now. Its coat is entirely white, which is an advantage for dyeing. The hairs are all modulated, which makes them lighter than wool (density 1.1 against 1.3) and increases their insulating properties. They have all the properties of keratin, notably insulation, water absorption and good dyeing quality.
The Angora rabbit's coat is 98.5 percent pure as cutaneous secretions (restricted to those of the sebaceous glands) are very slight and the animal grooms itself frequently (a sheep's fleece is 50 percent pure). Angora wool goes straight to the card without previous washing: it is imperative that the producer keep constant control over the cleanliness of the animals.
There are several grades of hair, identified by length, type of animal and cleanliness. For first-quality hair 80 percent of the coat must be over 6 cm in length, and clean. This grade was worth US$50 a kg in 1981, but only $10 a kg in 1971. Second-quality hair is clean but too short (under 6 cm) or too woolly. It is grown on the belly and extremities, and is worth about 20 percent less than the first quality wool.
The hair of the young Angora is shorter and softer. It is the product of the first and sometimes the second collection. The clean but felled hairs collected on the necks of females or breeding animals are worth only 15 percent of the value of first quality hair.
Dirty hair of any length is virtually worthless. At best, it is worth less than shorn hair from ordinary rabbit breeds. Its value would be no more than 5-6 percent of the first quality. Clean hair is therefore absolutely essential in angora wool production.
Angora rabbits are reared primarily for their hair. The production of this hair calls for an entirely different set of techniques from those used in meat rabbit production. These techniques have reached the pinnacle of specialization in France, where the sole target is wool production.
The adult female produces the hair: adult, because top quality Angora is only produced from the third collection at 9 months, and female because the female produces more hair than the male-an average of 1 kg against 700-800 g for the male. So the hair-producing stock is made up of adult females that are maintained as long as possible, with reproduction kept at a minimum. Gestation and lactation reduce hair production by one third.
The number of breeding bucks is kept to a proportion of only 5 percent. In France the males not destined for breeding are culled at birth.
The hair is collected every 90-100 days, when the follicles reach the resting stage and before hair starts falling, which would cause felting and reduce the value. The hair is cut with scissors or electric or manual shears, or collected by depilation. The hair from each rabbit is sorted into its separate grades as soon as it is removed. The summer collection is smaller, up to a third less than that of autumn and winter. The spring collection is between the two.
Collection takes a skilled operator about half an hour per rabbit. Shearing is a little quicker than depilation, but the hair is of slightly poorer quality. In addition, with certain strains of Angora rabbits the hair grows back unevenly after shearing, while it is more regular after depilation.
The Angora rabbit is raised in an individual cage on straw litter for two reasons: to keep the hair clean and to avoid the formation of scabs on the paws, which eventually happens on mesh floors as Angora rabbits are heavy (4 kg) and their pads are unusually delicate. Damaged paws will cause production to drop by 25 percent compared to litter reared animals, and the rabbits may die. Raising the animals in cages, a feature of the extensive system, does not require costly investment and allows a gradual increase of production. One person working full time (2 400 working hours a year) can care for 500 rabbits-feeding, care, collection of wool, etc.
Feeding Angora rabbits involves several peculiarities. Indeed the Angora at peak production is an adult rabbit from the physiological standpoint. Its growth is complete and reproduction is limited to a few animals. It must, however, produce over 2 kg of dry proteins a year- more than 1 kg of keratin (hair) and the same amount from the internal sheath of the hair follicle. This is the equivalent of 7 kg of muscle.
This explains the need for a high-protein diet-17 percent. The keratin in the hair is rich in sulphur amino acids, exporting 35 g of sulphur a year, so the proper intake of these amino acids (0.6 percent in the ration) must be ensured. French breeders give their animals top quality alfalfa hay supplemented by oats, which are preferred to other cereals. For a high production of hair 200 g of alfalfa hay and 100 g of oats are needed per rabbit per day. If the amount or quality of alfalfa hay is inadequate the diet should be supplemented by mixed concentrates, including feed cakes, dehydrated alfalfa meal, cereals, and vitamin, mineral and methionine supplements. Most Angora breeding units use this diet now. Some use solely the balanced pelleted feed designed for nursing does. In this case an average 170-180 g should be fed to each rabbit daily.
The Angora rabbit's feed requirements follow the cycle of collection (every 3 months) and hair regrowth. Requirements increase after depilation as the animal is then hairless and energy losses by radiation are very great. By the second month the animal is again well covered, but this is when the hair grows fastest so the ration must of course remain adequate. In the third month, requirements decrease because the hair grows more slowly and, as collection time approaches, starts to fall. Daily rations need to be adjusted carefully to these variable requirements.
It is now the practice to give 190-210 g per day of dry matter during the first month, 170-180 g during the second month and 140-150 g during the third month. If really necessary, in the 4 weeks after depilation a rabbit could be fed ad lib., but after this it must be rationed daily. It is also recommended that the rabbits not be fed 1 day a week so the stomach can empty, preventing or at least diminishing the risk of hair balls from self-grooming. The hair forms very hard balls (trichobezoars) which obstruct the pylorus and usually cause the animal's death.
The collection of the animals' hair poses problems of heat regulation for them. Just before collection the rabbit has an insulating mantle 6-10 cm thick, but after it is quite bare. The rabbits must therefore be kept at a temperature between 10 and 25°C (30°C at most). Most losses of adult Angoras occur during the days following hair collection as the animals then have problems maintaining thermal balance. They become particularly sensitive to respiratory germs (pasteurella, coryza, etc). The breeder must therefore be constantly on the alert regarding their general hygiene (frequent litter renewal, cleaning, disinfecting). Having to replace working females with young does lowers average production levels because first year Angora output is appreciably lower. Even more important, dirty hair is virtually worthless.
THE ANGORA IN DEVELOPING COUNTRIES
A point to be considered very carefully is that Angora rabbit production is labour intensive and also requires great expertise. The slightest mistake can mean the loss of productive adults-the animals have to be over a year old to return a profit. Carelessness downgrades the product (dirty hair, bad cutting, felting, poor sorting).
Above all, not all climates are suitable: excessive heat and intense light (albinos) are very bad elements. In cold countries the solution is to use buildings that shelter the animals against the rigours of the winter. Housing should in any case provide Angoras with a clean, hygienic environment, and this is not possible everywhere. Feed is also costly, unless a producer is content to provide a meagre feed which will keep the animal alive but will halve hair production.
Angoras can be raised for both hair and meat. A considerable reduction in the hair yield will result. German breeders use this system, but production techniques are very strictly adhered to. Chinese breeders probably also produce Angora hair from dual-purpose animals slaughtered relatively young for meat.
A last point to remember, and probably the most important: Angora hair prices fluctuate according to fashion, with a cycle of 3 to 5 years. In 1971 many units disappeared in France because Angora hair dropped to US$10 a kg, compared with $20 in 1965 (it was $50 in 1981). The world market is so small that any considerable increase in output would cause a price slump.
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