Chinchilla Rabbits- Past and Present
The Chinchilla rabbit originally came to the United States from England in 1919. And, as in Europe, it rapidly became a popular fur breed in this country, especially because of its color. During the 1920s, the Chinchilla became the most popular breed registered with the American Rabbit & Cavy Breeders Association (AR &CBA). The American Chinchilla Rabbit Association was formed in 1923 to promote the breed. Those wishing to make the Chinchilla a dual purpose fur and meat breed decided to increase the size of the original small Chinchillas, by selective breeding, to make them more marketable for a growing meat industry. The larger Chinchillas were given a breed status and became the American Heavyweight Chinchilla (now American Chinchilla). The smaller, original Chinchillas were named the American Standard Chinchilla (now Standard Chinchilla).
Through the efforts of Edward H. Stahl (Pearl River, NY and Holmes Park, MO), a third, and even larger, Chinchilla breed was developed, the American Chinchilla Giant (later American Giant Chinchilla, now Giant Chinchilla). He produced this breed, in the early 1920s, by crossing a Chinchilla with a New Zealand White, White Flemish Giant, and an American Blue, followed by crossing their progeny and backcrossing to the Chinchilla. With continued selection, the Chinchilla Giant became distinctly different in type and fur from the original breeds used in its formation. Compared to the Flemish Giant, it was somewhat shorter in length and had a less pronounced arch (approaching a commercial meat type), a slightly lighter bone, and less massive head and ears; does had a smaller dewlap. This breed was bred primarily for meat production. The American Chinchilla Giant standard was adopted in 1928 by the AR&CBA.
The quality of type, fur, and color of the Chinchilla breeds continued to improve during the 1930s and reached its peak between 1940 and 1960, fostered by good fur and meat markets and intense competition among many exhibitors. However, the Chinchilla rabbit fur market began to show signs of recession during the 1940s. It was being replaced by a white fur market dominated by New Zealand White and Californian rabbits. Supplying a sufficient quantity of matched Chinchilla pelts has always been a challenge for breeders. Dyed white furs appearing in a variety of colors were becoming more popular with time because they could be dyed to match closely. The finest matched Chinchilla pelts were used for making coats, jackets, and stoles; the best color and fur quality being found in young adults, not the juveniles or fryers. Consequently, Chinchilla rabbits producing the best pelts required extended maintenance prior to marketing. Markets for Chinchilla pelts were moderate throughout the 1940s, but reduced significantly during the1950s and dropped precipitously thereafter. Rabbit furs were largely replaced by synthetic furs during the 1960s, and the anti-animal fur movement began to flourish during the 1980s. The desire for natural furs was dying.
In the late 1940s, the American Chinchilla Rabbit Breeders Association voted to change the name of the American Heavyweight Chinchilla to the American Chinchilla and remove their sponsorship of the American Standard Chinchilla. Consequently, in 1949, a number of American Standard Chinchilla breeders held a meeting at the annual Poultry Show (it also contained a small rabbit show) at Madison Square Garden in Manhattan, NY, and decided to form their own specialty club, the American Standard Chinchilla Association (ASCA). Most of the breeders present were also members of the popular New Jersey Chinchilla Club that promoted the breeding of American Standard, Heavyweight, and Giant Chinchillas, and Chinchilla Rex.
In the 1950s, there were a large number of American Chinchilla breeders located in the Northeast and Midwest (also the adjacent state Kentucky). These regions had the most American Standard Chinchilla and American Giant Chinchilla breeders, although their numbers were less than the American Chinchilla breeders. Even though the Chinchilla fur market was dwindling, the meat market was still quite good. To the breeders’ credit, it took more than a decade of reduced market opportunities before the number of Chinchilla breeders declined significantly. Today, the Northeast is still home to a large portion of the Giant Chinchilla breeders, but no longer contains a major sector of the Standard and American Chinchilla breeders. California is now becoming a popular Chinchilla state.
American Standard Chinchilla
The original American Standard Chinchilla was raised primarily for fur and exhibition. In1950 the newly formed ASCA promoted it as a dual-purpose, fur and small meat breed. It regularly won the small fryer and roaster classes at commercial shows and had a high dress-out percentage. Many of the best bloodlines could produce 4 lb. fryers in 8 to 10 weeks. Their standard senior weights were 6-7½ lbs. for bucks and 6¼-8 lbs. for does. Much to the chagrin of some breeders the standard weights were dropped to 5-7 lbs. for bucks and 5½-7½ lbs. for does in 1996, making them less desirable today for commercial purposes.
The American Chinchilla was raised for both fur and meat and remained a commercial breed. They often placed just behind Californians, Champagne D’Argents, and New Zealand Whites in exhibition meat classes. Chinchillas are known for their very fine flavor, often exceeding that of the other competing breeds. Many lines produced 4 to 5 lb. fryers in 8 to 10 weeks. By 1951, the American Chinchilla standard senior weights were 9-11 lbs. for bucks and 10-12 lbs. for does, which have continued up to the present. A special dispensation was made for the year 1950, making the minimum weights of 8½ lb. for bucks and 9 lb. for does, so that American Standard Chinchilla breeders wishing to increase the size of their rabbits to that of the American Chinchilla, by selective breeding, would have additional time to accomplish their goal.
American Giant Chinchilla
The American Giant Chinchilla was promoted primarily for meat production and secondly for fur. It reached a market weight more quickly than the other Chinchilla breeds, but, because of its heavier bone, had a somewhat lower dress-out percentage. The meat of the younger rabbits was especially tender. The pelts produced were large and marketable, but generally lacked the fine texture and high density found in the other Chinchilla breeds. This breed was preferred by those who liked to raise large rabbits. The standard senior weights were 12-15 lbs. for bucks and 13-16 lbs for does, which have continued up to the present.
Some of the Chinchilla breed characteristics of the 1940 to 1960 period have been modified significantly in sectors of the populations remaining today. In some herds, changes have been made in the type of the Standard Chinchilla, so it conforms more closely to the type of a Florida White. The fur of all Chinchilla breeds is generally less dense and shorter than before. Unfortunately, current Chinchilla breeders do not have access to the very dense furs of the past for making comparisons. Ring color is generally not as white (ideal: intermediate band free of cortical intrusions containing melanin) and contrasting and the definition is not as sharp (ideal: uniform position and width of underfur hair bands and a very narrow transition region between light pearl and black bands). In many bloodlines, the surface color is relatively even in appearance (salt and pepper) (ideal: variable guard hair length with an attractive wavy distribution) and/or the exposed guard hair light pearl/black bands are not in high contrast. A significant number of bloodlines are too dark in surface color. Most lines of Standard Chinchillas and some lines of American and Giant Chinchillas now produce smaller rabbits than those of the 1950s and 60s; some of these have difficulty in attaining minimum standard weights.
American and Giant Chinchilla populations reached very low numbers by the end of the 20th century and became endangered breeds. For this reason, the ALBC placed them on the Conservation Priority List. In recent times, their dwindling breed populations have gone through a genetic/population bottleneck, resulting in a small gene pool. Genetic bottlenecks increase inbreeding due to the reduced number of possible mates available, and can result in weight reduction, smaller litter size, loss of vigor, susceptibility to disease, and/or the appearance of both desirable and undesirable recessive traits. For those breeders making full or half-sib crosses (close inbreeding) for several or more generations, the problem is magnified. Some American Chinchilla breeders are attempting to correct this problem, by outcrossing their bloodlines within the breed. As a commercial breed, it is important that does produce numerous healthy kits capable of making an early market weight.
Cross Breeding Not the Answer
The few breeders crossing their smaller American Chinchillas with Giant Chinchillas, to obtain an increase in weight, faced the difficulty of regaining the fur density and fine texture, medium bone, and type described by the American Rabbit Breeders Association (ARBA) Standard of Perfection. Although it would seem plausible to make American Chinchilla × Chinchilla Satin crosses to expand the gene pool, this approach also poses a problem, in that it often produces smaller animals that are darker in color than ideal and have relatively poor ring color and definition, and their fur characteristics are somewhat different. The recessive satin fur gene (sa) would also have to be eliminated from the herd by test crossing the progeny exhibiting normal fur. Breeders choosing to cross American Chinchillas to New Zealand Whites, can obtain a chinchilla-colored rabbit in the first generation, but, in addition to eliminating the albino tyrosinase gene from their herd, they would have obstacles to overcome in attempting to regain the wavy surface color, sharply defined, light pearl ring with black edging, and dark slate blue undercolor, components of the ideal Chinchilla coat color, and a very dense fur of fine texture.
The above are complex polygenic traits, each affected by several or more genes. Coat color components are determined by a combination of different modifying genes that control variation in melanin pigment production, agouti pattern, and the number, length, and distribution of the different hair types. Fur density and texture also have some influence on the Chinchilla surface color and ring color and definition. Poor nutrition and continued environmental stress can negatively affect coat color and fur.
The small Giant Chinchilla population of today is heterogeneous. It contains bloodlines perpetuated over many years without crossbreeding and bloodlines where crossbreeding has taken place at one or more different times. There are a significant number of Giant Chinchillas being exhibited today with features approaching that of the Flemish Giant. Although they are slightly smaller, other features make it difficult to distinguish this sector from the Light Gray Flemish Giant (the color of this variety is also determined by the chinchilla tyrosinase gene). Those breeders crossing Giant Chinchillas to Flemish Giants, to increase size, face the difficulty of regaining the more beautiful Chinchilla color and those other characteristics that distinguish the two breeds.
In conclusion, the best Chinchilla purebred bloodlines were produced by breeders who followed sound breeding principles and recognized and pursued the ideal traits described by the Standard of Perfection. In recent times, when the Chinchilla breed populations reached critically low levels, some or all of these outstanding bloodlines may have been lost. In the worst situation, remaining bloodlines should be crossed to the most distantly related lines within the breed to increase the probability of obtaining new, perhaps even better, gene combinations. Crossbreeding disrupts selected gene combinations and will likely produce some combinations that are not desirable. The introduction of undesirable gene combinations and traits can be largely avoided, if the breeder adheres to careful selection and strict culling practices, while attempting to rebuild the particular Chinchilla breed. Here the challenge will be to rebuild the breed and not replace it with a new chinchilla-colored breed that has much less genetic similarity.
It appears that some of the progeny of Chinchilla breed hybrids are being exhibited today, based on some changes noted in the original breed characteristics. The hybrids may be a work in progress. They reflect the frustration of some breeders in maintaining a quality Chinchilla herd in the face of a population bottleneck. Variation in type, color, and fur is high considering the small size of existing populations, and probably represent different crossbreeding schemes and/or different breeder preferences.
Rabbit breeds are usually formed by crossing breeds. But once established, a breed should be maintained as purebred. One exception to this principle may be when a breed faces extinction. With the current resurgence of interest in these breeds, it is anticipated that progress will continue in the direction of breed improvement and establishing more diverse purebred bloodlines.
Dr. Wesley Kloos is a Professor Emeritus of Genetics at North Carolina State University and lives in Fuquay-Varina, NC. He is a retired American Rabbit Breeders Association Judge and Registrar and was an American and Standard Chinchilla breeder and exhibitor in New Jersey from 1948 to 1962. His Homestead Rabbitry was one of the main suppliers of Chinchilla pelts and meat to the New York Metropolitan Area and New Jersey.