BREEDING FOR THE IDEAL SILVER FOX)....by Karen Fischer, President

First and foremost, the Silver Fox is a commercial breed. It is a versatile breed, which can be used for show, meat and fur. These qualities should be bred for and the goal of the breeder is to maintain and cull specifically for these qualities.

Silver Fox does overall are good mothers and good nest builders. They easily raise large litters and milk well. The breed is generally winter hardy and appears to maintain production well during cooler periods of the year, provided they are kept in production, fed well and maintained in good housing. Silver Fox are of a calmer nature than is commonly seen in other commercial breeds and often become quite personable.

Animals selected for breeding stock should be the best examples of the breed that one can secure and to cull routinely for less desirable qualities. Among the traits one should cull for are:

Failure to make weight - To select for the best animals, the breeder should keep detailed records of growth rates of an entire litter. Usually, the smaller offspring will mature to be smaller adults. Each rabbit in the litter should be weighed at birth, and every 4 weeks thereafter to determine the rate of growth of each of the rabbits. Marking the ears of the babies too young to tattoo will help keep accurate records. The litter should be weaned as early as possible and separated so that reduced feed intake cannot contribute to the reduced growth rate problem. On the date that the rabbit turns 8 months old, it should weigh not less than the adult weight for a buck or doe. It will continue to add weight after this time but much more slowly.

One point should be made here. Silver Fox should be bred to efficiently utilize their feed, that is, it shouldn't take extreme supplementation of the diet for the rabbit to attain senior weight. If it is necessary for the breeder to feed countless supplements in order to get the rabbit to weight (which is actually adding fat to the rabbit, not muscle), the breeding program is failing in this respect. Rabbits should be bred to be genetically programmed to attain and exceed the senior weight based on free feeding of good quality pellets, good quality grass hay and minimal amounts of grain. (This is assuming the breeder is taking care of parasites, mind you.) Free fed rabbits will develop their own dietary intake based on its own needs, generally will not overeat and the breeder can easily assess the full genetic potential of the animal, not its dietary potential.

Inconsistent or Extremes in Silvering - The silvering "gene" is actually a modifier gene that can be breeder selected. Four week old Silver Fox begin to develop silvering in a variety of patterns. Some will develop silvering in a patchy pattern, while others will develop it uniformly. Both will eventually (in most cases) even out in their silvering by the age of 6 months. Rabbits that fail to develop silvering should be culled. The standard calls for a uniform silvering. The degree to which the silvering occurs can vary to some degree for show purposes but should not be so heavy as to make a black Silver Fox appear gray.
Inconsistent silvering is most often seen in lightly silvered individuals, which may have some concentrated areas of silvering as well as very lightly silvered areas or some areas completely devoid of silvering. Heavily and lightly silvered animals that are uniform can be used in a breeding program to help correct the opposite problem in the animal it may be bred to, provided all other traits for that rabbit are favorable.

White Spots - Occasionally, white spots and toenails may appear in the Silver Fox. A phenomenon in some lines of Silver Fox is the appearance of a very small white spot on the forehead when young, which molts out and never returns. It is interesting to note that wild cottontail rabbits are born with such a spot (nearly all of them), which disappears when the rabbit is mature. The key word of advice in this respect is that one should cull all animals that develop permanent white spots, white toenails and areas of concentrated white hairs that would resemble a spot.
Wrong Fur Quality - The Silver Fox's hallmark is the long, dense upright silvered fur. There currently is a great deal of inconsistency in the fur of the Silver Fox. Coats can be found that are long, but the density fails and the coat may roll back somewhat. Other coats are shorter, denser and will also stand up or slightly roll back. Years ago, the author had the privilege of seeing and feeling the ideal Silver Fox coat, which has not been experienced since but obviously existed years ago. This coat is long, very dense and decidedly coarse in texture which stood up on it's own without the need to brush the coat from back to front. One could actually feel "resistance" to the coat. The problem is that most Silver Fox have two of the three qualities going for it in any given rabbit, but not all three from what the author has seen in recent years. To "gather up" all three qualities will take a great deal of selective breeding and strict culling. Animals with short coats should not be used in the breeding program as this trait is highly inherited and will continue to plague the breeder. Animals with the proper length and texture can be worked with to increase the density over time.

Bone - It is important to note that it is very difficult to get any fine boned animal to make weight and these animals tend to have problems with sore hocks and misalignment of the legs (cow hocks, which cause undercut lower hindquarters) and rotated hips (which cause pinched loin areas and accentuate the undercut appearance). Fine boned animals also tend to be longer in type, do not fill out or develop good flesh condition, fail to develop good muscular condition over the skeleton and may even develop bowing of the long bones as they mature. Silver Fox are to have medium bone. This means that as the rabbit develops, its skeleton can continue to handle the weight of the rabbit and abnormalities of the skeleton are less likely to happen since the musculature is able to develop properly without having to become "stressed and long" to support what the bones cannot. In young rabbits, the type of bone can often be ascertained by turning the rabbit over on its back and viewing the back feet. The feet should have a "short, fat" appearance to them and be exactly parallel to each other with good spacing (the spacing helps assess how the hind legs are set in the hip joints and how wide the pelvis is). If the hind feet are long and narrow, if the hind feet turn out (hocks in) or are too narrow when held next to each other, the bone on the animal is likely to develop into long, finer bone which is undesirable. Animals with long bone tend to be long in the midsection. Although the Silver Fox is to have a body type of medium length, excessive length in the midsection will cause the animal to be weak in the shoulders and loin areas (pinched) and detract from the smoothness of the animal from front to back.

Hardiness - No matter what breed one is raising, this trait should be just as important as type, fur and bone. Although not specifically an item called out in a breed standard, hardiness directly affects "condition" which is in the standards of all rabbit breeds. Animals that become ill easily, do not handle normal stress well, who do not properly raise a litter or fail in mothering instincts or milk production should not be considered part of the breeding program. Using such animals will produce more of them or weaken the hardiness of the rest of the herd. If the breeder has a refrigerator sized medicine cabinet at home and is treating rabbits on a constant basis for every imaginable ailment, one is not selecting for hardiness. Hardiness is a function of nature in the wild. Unfortunately, the domestic rabbit must rely upon man to provide the mechanism for "survival of the fittest." Less desirable animals should always be culled. If one is keeping a large herd, using less hardy animals will soon produce a very labor intensive herd. Good animals come from good stock. Preserving a "line" is far less important than breeding good quality animals.

Color Considerations - Aside from the white spots/nails and silvering mentioned previously, the Silver Fox has two varieties. Black (recognized) and Blue (being reintroduced for recognition). All attempts should be made to keep the color clean and true. Blacks can be bred to blues without any problems. The color of both should be as deep as possible, and to extend as far down the hair shaft as possible toward the skin. In a previous article I had written, I speculated that there may be some recessive genes at work in the Silver Fox that may have been undetected for a long time. Some Black and Blue Silver Fox that develop brassiness or "sun burning" during warmer weather might actually be "self chinchillated blacks and blues." There is a tendency for this color to develop a lighter under color than is seen in the true black or blue and they also could be somewhat lighter in color, detectable only if placed next to a true black or blue. It is important to breed for a deep jet black color in one's blacks and a deep gray blue in the blue to help eliminate the lighter versions of these colors. Other colors have turned up in the Silver Fox, namely the gray eyed white which seems to bear out this speculation. The use of these "whites" should be limited to very occasional breeding and such whites, if used, should be exceptional in all other respects (type, bone, fur density, texture and stand up qualities). As long as one is able to manage the genetics properly, severely limits the use of these whites and is honest about the existence of whites in the background to perspective buyers, these genes can be managed well. But it must be kept in mind that these whites do not carry the full color gene necessary to produce a true black but will produce true blacks if bred to one. It is very important that one determine if the buyer has the knowledge to work with this gene or not, as well as determining if they have an outlet for off-colored Silver Fox before selling such stock to them. If a potential buyer does not have an outlet for such rabbits, it is unwise to get them started with bloodlines that carry this gene. Large breeds, such as the Silver Fox, are less likely to be chosen for pet rabbits and this must be kept in mind whenever dealing with a genetic issue such as this. If the buyer uses culls commercially, then they have the necessary tools to selectively breed out the "white" in the background since culling and disposing of undesirable stock is not an issue hampering the breeding program.

Bloodlines - Although many breeders purchase stock from well known and winning breeders in the hopes of producing the same quality of stock, it should be kept in mind that the pedigree is not what is placed on the show table. The value of any rabbit should always be based on two potential uses, show and breeding. Not every rabbit can be both a good show animal and breeder. Some breeding quality animals can be worth their weight in gold in producing better than themselves on a consistent basis but may never do very well on the show table. A Grand Champion rabbit is worthless in the breeding pen if it never produces equal or better than itself. Breeding two Grand Champions together can produce nothing but culls or nothing but Champions and everything in between. And two animals that place consistently at the top of the class (but do not always win) could produce the next Grand Champion. Bloodlines are not as important as knowing which two rabbits will complement each other, regardless of what is shown on the pedigree. Granted, some lines raised by certain breeders may have an exceptional quality that one needs to introduce into one's herd, but this is not necessarily a function of "pedigree" but rather good breeding practices and knowledge. A buyer who does not know what to do with a quality breeding animal will not produce the quality of that animal until they learn what it takes to select animals that complement each other. All rabbits should be evaluated for show and or breeding based upon performance in each regard. Successful performance is "proof" of a rabbit's value with regard to showing, breeding or both. European breeders rarely maintain pedigrees. The value of any given rabbit is performance based.

Aggression - An angry 9-12 lb rabbit is not a pleasure to work with and can be a hazard to children who may inadvertently put fingers in a cage. Breeding for temperament should be a consideration from a management standpoint. Occasionally, a doe may become protective of her litter but this is generally temporary and with kindness, generally is overcome with time. Most Silver Fox does do not act out aggressively. Silver Fox are noted for being calm and "teddy bears" of the commercial breeds so aggressive behavior should never be bred in.

Evaluating a Litter

One of the best ways to evaluate a litter of Silver Fox is to follow the guidelines outlined above at 4 week intervals. However, it also helps to compare the entire litter to each other. Assessing the litter of 8, for example, much as a judge would, at 4 week intervals and recording the results will help to determine which rabbits are developing and which are not. Picking the "best" animal at 4 week intervals (bucks and does separate) should help assess performance later as a breeding animal as well. If a rabbit begins as the largest, but later stalls in its development, this animal may pass this trait on. Delayed silvering can also be assessed during this time. It is difficult to show a junior or even a 6-8 successfully if the silvering is not developing properly and uniformly until much later. For the show barn, this would be very important to know since delayed silvering or inconsistent early silvering virtually eliminates the showing of juniors and 6-8 animals and does not give the breeder the chance to compare its juniors and 6-8 animals with those of other breeders. Assessing the litter for type, bone and development of fur qualities and silvering in this way will also help educate new breeders into recognizing potential problems earlier and helping them to cull earlier rather than waiting to see how the animal develops as a senior. It helps new breeders develop a "yardstick" of milestones that they can check at an early age so that they are not feeding an entire litter of 8 to senior age.

One of the more difficult traits to assess in very young rabbits is the fur quality. However, two qualities can be assessed fairly early, length and density. These should be obvious from an early age. Texture is much more difficult to assess since many baby coats consist of far fewer guard hairs (which affect the texture) and are mostly soft undercoat and finer guard hairs. It is also misleading when the rabbit begins to develop silvering since the vast majority of the silvered hairs are guard hairs and these could make the coat appear coarser at an early age but later, may not provide sufficient texture in the mature coat. Not all of the guard hairs in the mature coat will be silvered, but all of them contribute to the degree of coarseness of the coat. If the young rabbit silvers out early, but fails to develop any further guard hairs as a senior, the coat might fail in texture as a senior.

Strategies:
1. Buy the best stock that you can afford. Also realize that each rabbit must be assessed on its merits as a show and breeding animal.
2. Maintain a clean, well maintained rabbitry so as to eliminate husbandry as a cause for poor quality in ones animals.
3. Provide free choice pellets and grass hay with clean fresh water and limited supplements. The only way to assess genetic potential is to keep all factors as normal as possible.
4. Be willing to cull (sell, pet out, meat out) rabbits that will not or do not work in your breeding program. Do not keep or use any animal to "preserve" a line if that animal is not hardy or has any undesirable trait.
5. Establish an assessment program for evaluation of litters born and their development. Also continue to assess adult rabbits for quality and performance.
6. Learn all you can about what the Standard of Perfection calls for in the Silver Fox but do not forget to include all ARBA disqualifications. Breed to the standard and do not deviate.
7. Do not rely on pedigrees as a gauge on quality as a show or breeding animal. Make the rabbit "prove" its worth based on performance.
8. The definition of a breeder: One who attains knowledge, sets goals and is always improving … "

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