Rabbit Lactation

It is often said with truth that the quality of rabbits ismade in the nest. The first three weeks of the rabbit's life,when it should feed on milk from the doe only, are veryimportant, and will affect its future growth, developmentand ability to thrive.
'The mammary glands whirls manufacture the milk starttheir development early in pregnancy, although this develop-ment is relatively slow until about the last week. During thelast week of pregnancy the mammary glands develop rapidly,and milk may be produced by about the twenty-ninth day.'The growth and development of the mammary glands ismuch affected by the improvement in condition of the doethroughout pregnancy. A doe which is in high conditionat the start, and remains in that condition throughout theperiod, will not have such well developed mammary glands as one which improved throughout the period. It is thisimprovement which is important.

During the lactation period, which usually lasts at mostabout seven weeks, although the young may occasionallysuckle after this period, the milk yield varies. The peak isreached after about the first fortnight and thereafter itremains fairly steady until a decline in production commencesabout the end of the fourth week.

Suckling by the young rabbits keep the mammary glandsin active operation, and therefore if they reduce their suckling,or if their number is reduced, the actual milk production willbe lessened.

The milk of rabbits is the richest of all domestic animals.It contains from 13 to 15 per cent of protein, to to 12 percent of fat, 2 per cent of sugar, and 2 to 3 per cent of minerals.The gross energy is about t,000 Calories per lb., and thiscompares with about 350 Calories per lb. for cow's milk and750 Calories per lb. for milk from the bitch. The very highvalue of rabbit's milk explains the rapid early growth of theanimal, but it means that the doe will require a good deal offood for the manufacture of the milk.
The yield of milk from the rabbit is influenced by severalfactors, including inheritance. For this reason it is importantthat the yield of milk should be considered when selectinganimals for future breeding.

There is of course a good deal of variation between differentdoes in respect of their yield of milk. Unfortunately thereis no simple direct method of measuring this yield, althougha fairly reliable indirect method is the measurement of theweight of the litter at three weeks. There is also the factthat if the doe is not giving sufficient milk the young rabbitswill leave the nest early in search of other food. The reasonwhy the total weight of the litter is a fairly reliable index isthat the major limiting factor in growth is the supply.of milk.There is however an important point which must be takeninto consideration when this index is being used. The samedoe will yield different amounts of milk with different sizedlitters, for although the amount of milk will increase withincreasing size of litters, the amount of increase will not be in direct proportion. Further of course, the age of the doewill have some effect. The first litter of a doe will almostinvariably be lighter than an equivalent litter which in hersecond or third, and an old doe will yield progressively less milk.Prior to the introduction of the high level nutritional regimesit was rare for a domestic rabbit to become pregnant whilstsuckling, a condition strangely enough opposite to that whichoccurs in the wild rabbit. At one time, although does mighthave been mated and become pregnant up to about ten daysafter kindling and again after the thirtieth clay, between thesedates she would rarely mate. Post partum mating, i.e. matingwithin a few days of kindling, was almost invariably successfulin that the does became pregnant but they rarely carried young-sters to full term.

This situation is now changed to an extent. In order toobtain very high levels of meat production, that is to say fiftyyoungsters per year reared to meat weight or say a minimum of15o lbs of live weight gain per doe per year, early re-mating andearly weaning may be used. This re-mating within ten days ofkindling with weaning at 25-24 days may be employed as onesystem. Alternatively re-mating at 21-28 days and weaningshortly thereafter can be used as an alternative. These earlyre-mating systems are used only in commercial husbandry toproduce large live weight annual production. They undoubt-edly shorten the productive life of the doe and necessitate veryhigh feeding levels.