COMMERCIAL RABBIT RAISING 



31 



age, and milk can be expressed 

 from the glands for several days 

 thereafter. 



The amount of milk produced 

 depends upon several factors such 

 as breed, strain, diet, and genetic 

 constitution. Various studies of 

 milk production in the rabbit in- 

 dicate that during the height of 

 lactation, milk yield may reach 35 

 grams per kilogram of live weight. 

 On this basis, a 10-pound doe 

 would produce approximately 140 

 grams (5 ounces) of milk per day. 



Contrary to popular belief, the 

 doe does not nurse her young 

 throughout the 24-hour period. 

 For the very young in the nest 

 box, nursing is usually performed 

 during the night or early morning. 

 It may consist of a single feeding 

 of only a few minutes. After the 

 young leave the nest box and are 

 consuming solid food they will try 

 to nurse several times during the 

 day. However, the doe will usu- 

 ally push them aside and restrict 

 their nursing to the nighttime. 

 Occasionally, does will allow the 

 young to nurse during the day, as 

 most rabbit breeders will agree. 

 Students of animal behavior at- 

 tribute the nursing habits of the 

 doe to the fact that rabbits in their 

 natural habitat are extensively 

 preyed upon and rather helpless to 

 defend their young. Therefore, it 

 is advantageous for the doe to stay 

 away from the young as much as 

 possible. 



Factors That Limit Conception 



Among the causes of failure to 

 conceive, or low conception rates, 

 are false pregnancy (pseudopreg- 

 nancy), season of the year, age, 

 poor physical condition, sore hocks, 

 injuries, and disease. 



Pseudopregnancy. — Does may be 

 mated or stimulated sexually and 

 shed the egg cells, yet fail to become 

 pregnant. This false pregnancy 



may be caused by an infertile 

 mating or sexual excitement when 

 one doe rides, or is ridden by, 

 another. Does which become pseu- 

 dopregnant are unable to conceive 

 until the false-pregnancy period, 

 which lasts 17 days, is over. After 

 18 to 22 days, the doe may give 

 evidence of the termination of false 

 pregnancy by pulling fur and at- 

 tempting to make a nest. When 

 false pregnancy has terminated, 

 doe will resume normal reproduc- 

 tive activity and may be bred. 



Separate does that are to be 

 mated and put each in an individual 

 hutch 18 days before mating. 

 They will have passed through any 

 false pregnancy period by mating 

 time. 



Season.' — Spring is the optimal 

 breeding season for the rabbit. 

 The percentage of conceptions is 

 higher at this time of year than at 

 others. 



Extreme temperatures, especially 

 sudden changes to high tempera- 

 tures, may cause the rabbits to go 

 into a barren period that will con- 

 tinue for some time. Also, it is 

 not unusual for the percentage of 

 conceptions in a herd to show a 

 marked decrease during the late 

 summer and the fall. For example, 

 at the U.S. Rabbit Experiment 

 Station conception rates varied 

 from a high of about 85 percent in 

 March and April to a low of 50 per- 

 cent or less in September and Octo- 

 ber. This is commonly referred to 

 as the "fall breeding" problem in 

 rabbits. The ovaries of the does 

 may become inactive during the 

 barren period, fail to produce nor- 

 mal egg cells, and occasionally 

 shrivel. Where the bucks are not 

 settling the does, the sperm cells 

 may be inactive, low in vitality, 

 abnormal, or absent. 



Individual rabbits vary mark- 

 edly as to duration of the barren 

 period. Some does and bucks are 

 fertile throughout the year for 



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