Rabbit Breeding

There are many lessons in correct breeding procedure tobe learnt from a study of the reproduction in domestic rabbits.Good breeding practice must be based on a knowledge ofreproduction. One of the most important is that concernedwith the proper nutrition of the doe to produce the desiredresult.

The selection of animals for breeding, ignoring theirinherited characteristics for the moment, depends on health,condition and age. No matter how good an animal may bebecause of its ability to transmit a good inheritance to itsprogeny, unless it has good health, and is in the right condition,it is not suitable for breeding. A sick doe cannot possiblybe a good mother, and may quite easily infect all her offspring.Condition suitable for breeding is rather more difficult todefine. The doe should not be fat, but should be well fleshed,and most important, site should be in improving condition.The correct age for first breeding is important. It is oftenwise to breed slightly before the age of sexual maturity, andin this the breeder should be guided by the bodily develop-ment of the animal rather than by a question of months.Too early an age is not desirable, but neither should ananimal be left too long, except for some special reason suchas showing, before it is mated. Does will continue to breedin some cases for a number of years, but in general a threeyear old doe will often be discarded unless she is above averagequality. In the case of the smaller breeds, five months atthe earliest, and usually six months, is the age at whichbreeding should start. For the largest breeds, it is not usualto commence before eight or nine months.

The number of litters which a doe should be allowed tohave during the year is often the subject of argument. Ingeneral the fancier will usually breed the doe twice andoccasionally a third time. The aim of the commercialbreeder should be to take four litters a year. There is littleharm likely to result from frequent breeding. Indeed thereverse is true. If feeding and management are satis-factory, then frequent breeding is desirable.

A method sometimes adopted to obtain as many offspringas possible from a particular pair of animals is the repeatedmating of the doe and the fostering of the young on to fosterdoes. In this way as many as eleven litters can be taken inthe year, the doe being remated immediately after kindling.Contrary to general belief such a system imposes less strainon the doe than does intermittent pregnancies and suckling.A similar system is sometimes used to increase averagelitter size and fertility. In some of the smaller breeds, theNetherland Dwarf in particular, difficulty may be experiencedwith breeding. Thus several does are mated at the sametime, and average litters of five or six fostered on to somedoes, whilst the others are rebred. This assists in gettingfertile matings, and also assists in keeping youngsters small,a desirable characteristic in these breeds.
The doe should never be mated in her own hutch for thismay lead to her resenting the intrusion of the buck andconsequent fighting. She should always be placed in thebuck's hutch, or in a special service hutch. It is of advantageto allow a buck at least his first services in his usual surround-ings. Some bucks may refuse or be sin,' to serve in strangeconditions.

The doe should not be left with the buck for any con-siderable period, and the mating, which should normally beaccomplished in a very short time, should always be observed.If no mating takes place within a few minutes then the doeshould be removed and retried later. By placing his hand infront of the doe, a breeder may often make her stand to thebuck instead of running from him.
As soon as the mating is completed, the buck falls back-wards, or in the case of a less vigorous buck scrambles fromthe doe. The falling of the buck is due to his becomingunbalanced. Usually when mating is accomplished a screamwill be heard. This is usually uttered by the buck, althoughit may occasionally be made by the doe. It is the result ofsome pain and is perfectly normal.

A method of assisted matings has been developed for usewith reluctant does, and also in cases of shy bucks. The doeis grasped by the loose skin on the shoulders whilst with the other hand the hind-quarters are slightly raised, the vulvabeing pressed backwards and upwards with the finger andthumb. The doe thus adopts the normal mating postureand is available for the buck. This system does not, contraryto some belief; affect the number of infertile matings, but is ofassistance in procuring more matings than would otherwisebe the case.

The stud buck is a most important animal in a rabbitry,and should be used carefully. There is little doubt thatyoung bucks are easily spoilt by overuse, but on the otherhand it is equally true that fully mature bucks are not oftengiven sufficient work.
The first few services of a young buck should be well spaced;that is one or at most two a week. When the buck is fullymature, and well managed and fed, he can accomplish atleast six matings a week with ease. The first services of a buck which has beenrested for a long period may be infertile and in these casesa double mating should be made.
Some authorities advocate regular double matings. Thismethod is to mate a doe and then an hour or two later tomate her to a second buck. The system has little to recom-mend it for a vigorous buck will accomplish all that is desired,and when two bucks are used the parentage is not known,a serious disadvantage for future selection.
A buck should not be put to service immediately afterfeeding, for mating at such times imposes an unnecessarystrain upon hint. Similarly it is better to space matings onthe same day as much as possible. It must always be remem-bered that a stud buck used reasonably frequently is beinghard worked, and should be fed well and looked after.It is frequently said that the quality of the young is affectedby the age of the buck. There is no truth whatsoever in thisstatement. Many breeders will discard a buck simply onthe grounds of age. Such a practice should be stronglycondemned. The older a buck gets, provided he still remainscapable of service, the more valuable he may become, for thebreeder will have a greater knowledge of his capabilities asa stock getter. This argument also points that of the early use of a buck. The snore young a buck begets, the moreable is a breeder to assess his qualities, for the value of astud buck lies entirely in his ability to transmit good character-istics to his progeny.

Fostering is the art of transferring offspring from one doeto another. There are advantages in using this art, but insome cases there may also be disadvantages. One dis-advantage is that unless the new born animals are wellmarked their true identity may be completely lost unlesswhole litters are transferred and the young of the foster doedestroyed. Secondly the true value of the mother cannot beassessed unless she is left with a full sized litter. Fostering.enables a breeder to obtain young from a doe with particularcharacteristics, but very often her quality as a milk producerand rearer of young are ignored. Its general this is not verysatisfactory.

On the other hand fostering would enable a breeder toproduce a large number of young from a particular mating,and it also enables litter size to be averaged out, thus gettingthe best results. Sometimes when it is only desired to reara particular type of animal, as for example reasonably wellmarked patterned animals, fostering would assist in that allthe does can be mated, the desired youngsters selected fromall those produced, and then fostered on to one or two does,the remainder being again mated. This same proceduremay be adopted when animals of a particular sex are required,for example for laboratory use. When a doe dies, or pro-duces her first litter, fostering may be of use. Thus thedecision to foster must depend upon the particular require-ment of the individual breeder, and provided the objections areconsidered and overcome then fostering can be extremely useful.Young rabbits up to the age of three weeks may be fostered,although at this late age it will not always be successful.When it is proposed to reduce a litter it is best to reduce itonly after a few days. This is because suckling will stimulatethe milk secretion, and consequently by fostering only aftera week the maximum activity of the mammary glands willhave been achieved. As far as possible however, fosteringshould be carried out within at most ten days of birth.

Litters as much apart as three days can be successfully amal-gamated, although usually it is preferable that the littersshould be as close in age as possible. When differently agedlitters are being amalgamated it is of advantage to foster theyounger animals and not the older.

Fostering is accomplished by transferring the young intothe nest of the foster doe. It is advisable to remove the doefor a short period and then give her some tit-bit when she isreturned to her hutch. Care should also be taken to observethat she takes to the youngsters and does not attack them.When a doe is being used as a foster for the first time, orwhen her mothering qualities are rather uncertain, then itmay be advisable to affect her sense of smell for a short period.This may be accomplished by rubbing a very little " Vick "ointment or paraffin on to her nostrils and fore legs.It is desirable for the breeder to be able to tell as soon aspossible after a mating whether that mating has been successful.If the doe is not in kindle she can be remated, or a watchkept for signs of her being pseudo-pregnant. If the doeproves to be in kindle then she can be managed and fedaccordingly.

The most reliable method, and that giving the earliestconfirmation of pregnancy is palpation of the abdomen.The method consists of feeling the abdomen to decide whetherdeveloping embryos are present in the uterus. The tips of thefingers should gently press the abdomen just in front of thepelvis, when, if the doe is pregnant the embryos can be felt.These are about the size of marbles (between the 12th and14th day), but care should be taken to make sure that thefaecal pellets are not mistaken for the embryos. If a pregnantdoe of about 12 days duration is sacrificed and opened, thenthe relative position and size of the organs can be determinedeasily. It is important when palpating the abdomen that thedoe should be relaxed, for tightened abdominal muscles makethe task more difficult. Does cannot be palpated easily beforeabout the twelfth day of pregnancy.

A method 'which, although it has been used very widely, isnot very reliable, is that of test mating. The doe is returnedto the buck some days after mating and it is assumed that if she accepts the buck then she was not pregnant, whereas ifshe refuses the buck it is assumed that she seas. A pregnantdoe will however often accept the buck during pregnancy,and a doe not in kindle may sometimes refuse him.

The third method which may be employed on about the 24thday of pregnancy is quite reliable and consists in noting theincrease in thickness of the mammary glands. The mammaryglands start to increase in thickness about the middle of preg-nancy, and by the 24th day are sufficiently different frommammary glands in non-pregnant does to decide easily. Itis of advantage to feel the thickness of the glands in a knownnon-pregnant doe at the same time as testing the supposedpregnant doe.

The domestic rabbit has been widely used to developartificial insemination, and thus the correct techniques areknown and available. It is doubtful however whether theywill be much employed by the rabbit breeder, except possiblyfor special purposes, such as the mating of animals verydifferent in size.

Briefly the technique consists of the collection of sperm fromthe buck in an artificial vagina, consisting of a glass tube about inches in diameter into which is fitted a rubber sleeve.This sleeve terminates in a small tube. Warm water is in-troduced into the large tube and thus warms the rubbersleeve. The artificial vagina is held between the legsof the doe or in an artificial muff, and the buck induced toserve into it. The semen is collected in the small tube anddiluted with a solution of up to 15 times its original volume.The doe is then ovulated, either by injection of appropriatehormones, or by mating with a buck which has been madesterile by surgical operation. The semen is then introducedinto the vagina with the aid of a glass syringe.