Rabbit Production. James I McNitt
5.8. Specimens showing the relative location and size of the uterus of a non-pregnant doe (left) and of a doe that is 10 days’ pregnant (right). (Courtesy of USDA)
Fig. 5.9. Specimens showing the relative location and size of the uterus and developing embryos at the end of 14 days (left) and 25 days (right) of pregnancy. (Courtesy of USDA)
There is little danger in palpating, provided it is done at the proper stage of fetal development and the proper technique is followed, but you must use caution and not put too much pressure on the tissues, in order to prevent injury to the developing embryos. The test will be more accurate and there will be less danger of injury if the examination is made about two weeks following mating. Between the tenth and twelfth days of pregnancy, the embryos are each about the size of an olive and are distributed in the uterus as indicated in Fig. 5.9 (left). With the thumb placed on one side of the uterus and the index finger placed on the other side, apply sufficient pressure to note the marble-shaped bodies, or embryos, by allowing the thumb and finger to slide over them gently. If the technique has been perfected and no developing embryos are found, the doe should be returned to the buck’s cage for another service. Many does will not rebreed 10 to 12 days after the original breeding because of pseudopregnancy. The vulvas of these does should be checked daily and the does bred when the color of their vulvas turns red or pink (usually about 18 days after the original service). Non-pregnant does should be kept on a ration that is suitable in quantity and quality for dry does until they are known to have conceived or are culled.
After a few days, the inexperienced person should re-palpate the does that were diagnosed as non-pregnant. If a mistake was made at the first handling and a doe is now found to be pregnant, she should be placed immediately on a management regime that is suitable for pregnant does.
Day 12 of gestation is probably the best stage to learn to palpate. After the fourteenth day it is more difficult to distinguish between the developing young and the digestive organs when palpating (Fig. 5.9, right). After the technique has been developed, however, it is possible to determine pregnancy by the tenth day. If you palpate earlier than 10 days following mating, the embryos are very small and you must make sure that pellet-shaped fecal material in the large intestine is not confused with the small embryos in the uterus. You can avoid confusion by remembering that, with the animal in the proper position for palpating (Fig. 5.7), the uterus lies at the bottom of the abdominal cavity, with the large intestine above it and nearer the backbone of the animal.
As you gain proficiency in the practice and become better acquainted with the anatomy of the organs in the abdominal cavity, it is possible to identify retained or mummified fetuses and the presence of abscesses or cysts in the reproductive tract. When any of these conditions are detected, the doe should be culled.
It is a good idea to re-palpate does at the time the nest box is added to the cage (usually 28 to 29 days after breeding). The reason for the second palpation is that occasionally does will conceive normally but later will resorb the embryos. If the fetuses die before 19 days of gestation they are resorbed, whereas if they die after 19 days of gestation they are aborted.
Palpation for pregnancy is a must for commercial rabbit raisers. The profit of an operation depends on the production of live litters on schedule. Palpation at 12 days of gestation saves 19 to 20 days of feed and labor, because if the doe is found to be non-pregnant, she can be rebred immediately.
Kindling
The nest box should be placed in the cage 28 or 29 days after the doe has been bred. It should contain bedding of hay, straw, shavings, or similar material. The doe will make a nest of these (Fig 5.10), after which she will pull fur (Fig 5.11) from the hip area, the dewlap, and around the mammary glands to complete the nest (Fig. 4.15). Care should be taken when inserting the nest box to ensure that it is not placed in the doe’s latrine area or where the waterer may drip into it.
Fig. 5.10. A doe making a material nest. (Courtesy of USDA)
Fig. 5.11. A doe pulling fur and making a nest for the forthcoming litter. (Courtesy of J.I. McNitt)
A doe will usually consume less feed than normal for two or three days before birth, and a small amount of green feed each day may tempt her appetite and have a beneficial effect on the digestive system. She should be made as comfortable as possible and should be undisturbed at the time of kindling. A majority of the litters will be kindled during the night. Both the anterior or breech presentation are normal, and as a rule there are no complications at delivery if the fetuses are normal in size. Occasionally there may be only a few kits in the litter, and in these cases one or more may be abnormally large and kindling may be delayed a day or two.
As each kit is delivered, the doe licks it and may nurse it immediately. When the entire litter is kindled, she pulls more fur from her body and covers the litter.
A normal litter that is clean and has full stomachs and a comfortable nest has made a good start in life. If a doe has not kindled by day 32 to 34 of pregnancy, one method that may be used by experienced breeders is to inject the hormone oxytocin to induce labor. Kindling usually occurs within five minutes after the intramuscular injection of 2 units of oxytocin (1 unit for dwarf breeds). If the doe has not built a nest, some fur can be taken from other nest boxes to make one. Does induced by oxytocin rarely kindle in the nest box, so the kits should be picked up as soon as they are born and placed in the box. The doe will usually accept the litter.
Care of Young Litters
Following kindling, the litter should be inspected and any dead or deformed young removed. If this inspection is done quietly after the doe has left the nest box, the doe will not be disturbed and there is no danger of her injuring the young. Examine the kits to make sure they have nursed, as will be shown by full stomachs. A full stomach appears as a white band (the so-called milk line) seen beneath the surface of the abdominal skin (Fig. 5.12). If a doe does not feed her litter or has not produced enough milk, the litter should be fostered to other lactating does. Does that repeat this abnormal behavior with the next litter should be culled.
Fig. 5.12. One-day-old kits. The one on the left is a “starve out” which has not nursed, whereas the one on the right has a full stomach. Kits that have nursed have a visible “milk line” in their stomachs. (Courtesy of H. Ch. Loliger)
Occasionally the kits will become separated and will form two groups within the nest box. With small kits, there is danger that only one group will be fed. When this happens and one group of kits does not appear to be cared for, rearrange the bedding into one nest, with the depth of the nest and the fur covering regulated to keep the young comfortable. A large litter sometimes becomes split, but the doe cares equally well for both groups. If this is the case, no intervention is required. Make sure that there is bedding under the young and that there is good drainage