reddish mucous membrane that, in the case of the buck, can be made to protrude sufficiently to form a circle; in the case of the doe, it will protrude and form a slit that will have a slight depression at the end next to the anus. In addition, the distance between the penis and the anus is greater than the distance between the vulva and the anus.
Until the technique of sexing rabbits has been perfected (Fig. 5.14), it may be a good plan to sex the young at weaning and then practice with several at about three weeks of age. In the older rabbits, the vulva will have a definite slit appearance. The penis will develop a more tubular appearance. This will make it easier to determine the sex of the three-week-old rabbit. Constant irritation of the tender parts may be detrimental, so sexing should not be practiced on the same rabbit at short intervals.
Fig. 5.14. External genitalia of the male (upper) and female (lower) rabbit. (Courtesy of D.J. Harris)
Tattooing and Ear Tags
An efficient, permanent system for identification is a necessity. Tattooing figures or letters, or a combination of the two, in the rabbit’s ear does not disfigure it, is permanent, and is easily accomplished. When young are being fostered, a hand tattoo needle is satisfactory for making one or more dots in each kit’s ear so the transferred young can be identified. It is also used by many breeders for the regular tattooing work in the rabbitry; others prefer the plier or tongs with removable figures and letters. After the inside of the ear is thoroughly cleaned with alcohol, either instrument may be used to perforate the inner surface of the ear. Tattoo ink or India ink should be rubbed into the perforations immediately (Fig. 5.15). The registration number for purebred stock is usually tattooed in the right ear and the rabbit’s individual mark or number in the left ear. A tattoo box that has movable parts so it can be adjusted to different sized rabbits (Fig. 4.18) holds the animal steady so one person can do the tattooing.
Fig. 5.15. A permanent identification mark tattooed in a rabbit’s ear (Courtesy of J.I. McNitt)
Rabbits can also be identified by the use of ear tags. These are produced as wing bands for chickens and are available from poultry supply houses. They are easily inserted using a simple tool (Fig. 5.16). Ear tags are sometimes lost, so identification is not as permanent as with tattoos. One method to make eartags less vulnerable to loss is to fold the ear and insert the tag halfway across the fold. When the ear is straightened out, the tag will be in the middle of the ear and have less chance of snagging on something and tearing out. For temporary identification, marking the ears with a felt-tipped pen is useful.
Fig. 5.16. An ear tag for easy identification. (Courtesy of OSU Rabbit Research Center)
Care of the Herd in Hot Weather
Rabbits must be protected from rain and sun. Good circulation of air throughout the rabbitry is a must, but strong drafts and winds should be avoided. It is essential that the animals have a supply of water available at all times. Temperature, humidity, and air currents all have a direct bearing, and each rabbitry is an individual problem. Adequate shade should be provided.
Rabbits suffer more from heat than cold; it is necessary to give the herd special attention during periods of high temperatures. They are more uncomfortable in high temperatures the first few hot days in the season. Does that are well advanced in pregnancy and newborn litters are the most susceptible to injury. The does give evidence of suffering by excessive moisture around the mouth and nose and occasionally bleeding from the nostrils, rapid respiration, and restlessness; newborn litters by extreme restlessness. Rabbits that show symptoms of suffering should be removed to a quiet, well-ventilated place. Considerable relief can be given by placing a wet cloth in an animal’s cage for it to lie on. In the case of the doe that has advanced to the stage where bleeding is occurring and quick action is necessary, placing cracked ice between the folds of a wet cloth and placing it in the cage so she can lie on it is quite effective and may save a doe about to kindle. Immersing the entire animal in cold water for three seconds is another emergency measure to save a heat-stressed rabbit. Many rabbit breeders freeze two-liter soda bottles filled with water and place them in the cages when it gets very hot.
Sprinkling the roof and floor of the rabbitry may give relief, except in areas of high humidity. If a roof sprinkler is thermostatically controlled, it will take care of quick weather changes and is especially useful if the caretaker is not available for regulating the sprinkler. If it is extremely hot, sprinkling the rabbits is another possibility, especially the does that will kindle in the next day or two. Be careful not to wet any feed in the feeders. Heavily pregnant does do not seem to be able to dissipate the heat as well as other rabbits, and giving them a cool dip or sprinkling may be the only way to save their lives.
Fur Chewing
When there are several rabbits in a cage and the habit of fur chewing develops, the eyelashes and whiskers are chewed first, then the fur on the head and on the body. Rabbits that are alone in a cage chew the fur on their sides or back of their rumps and are capable of reaching fur on the sides of their body where it would seem impossible. If rabbits can reach the coat of another rabbit in an adjoining cage, they may chew its fur. Sometimes does chew the fur on their own young. In cases in which rabbits are chewing their own fur or the fur of other rabbits, the coats have an uneven appearance (Fig. 5.17).
Fig. 5.17. Examples of fur chewing. The dark patches are areas of exposed skin. These rabbits were fed a diet containing sunflower leaves, which contain tannins that react with protein to cause a protein deficiency. (Courtesy of OSU Rabbit Research Center)
Fur chewing is most likely due to a faulty ration or to the rabbits not receiving the proper amount of feed and is usually associated with a ration that does not contain enough fiber. Keeping good quality hay or straw available at all times and feeding small quantities of green feed daily will assist materially in preventing the fur chewing habit from developing. If the feeding of hay does not solve the problem, increasing the protein content of the ration might help. The addition of 2½ kg of magnesium oxide per ton of feed sometimes aids in control of fur chewing.
Occasionally rabbits will pull fur from their cage mates because of boredom. This vice is overcome by putting a round can or a wooden block in the cage. The rabbits spend hours chewing and playing with these objects and seem to forget about the fur chewing. Hanging a small block of wood in the cage will also work and will also provide the additional benefit of reducing fighting. This method of prevention does not work if there is a dietary deficiency.
