7. Rabbitry management
Contents - Previous - Next
Organizing a rabbitry
Questions of management are discussed in various parts of this book. This chapter brings these different aspects together. The technical and economic criteria presented apply primarily to rational rabbitries of a certain size (at least 50 does). The rules of technical management are the same for smaller units, but the economic variables are different. The objective of small-scale units is not to make the greatest possible profit, but to achieve satisfactory productivity with a low input system using local resources and family labour.
The production cycle
As ovulation in does is provoked by mating, and the females are generally kept in different cages from the males, it is the breeder who determines the reproduction rate of the unit. These rates vary from 1 or 2 litters a year under the most extensive management to 8-10 litters in an intensive management system. In rational European rabbitries does are remated either immediately after kindling (intensive system) or about 10 days later (semi-intensive). European backyard rabbitries use a more extensive system, presenting the doe to the buck 1-2 months after kindling. Young does are first presented for mating at 4-7 months, depending on the breed (lighter breeds are usually more precocious) and especially on the diet.
In the semi-intensive system illustrated in Figure 32, the does are first presented to the buck at 41/2 months. They are then mated 10-12 days after the birth of each litter. Weaning (separation of doe and young) takes place at 28-30 days. Many European breeders (France, Italy, Spain) manage intensively: mating does within 48 hours of kindling and weaning the young at 26-28 days. This, however, requires very good feeding and a producer with a fairly high level of expertise.
Extensive systems are characterized by a long delay between kindling and mating, and perhaps even until weaning. For example, the young may be weaned at 56 days and the doe mated after weaning. This system is still practiced in France in farm rabbitries, where breeding does are fed fodder and grain.
FIGURE 32.-Production cycle of the domestic rabbit
At weaning the young are separated from the doe. The duration of fattening varies, depending on the carcass weight required and the growth rate possible in the feeding and production conditions of the rabbitry.
In intensive European production, where weaning takes place at 1 month, the fattening period is 7 weeks. The rabbits weigh 2.3-2.4 kg (liveweight) when they are ready for the market. Some African breeding units where weaning takes place at 2 months are reported to need a 4-month fattening period, because balanced concentrates are not available. European and North American countries which market rabbits at liveweights of 1.7-1.8 kg use a different system. The young are not weaned. They are left with their doe up to the age of 2 months, when they are sold. The mother is remated 3 weeks before that. This latter system can produce 5-6 litters a year.
Servicing is always done in the buck's cage. The breeder checks the doe's health at this time to make sure she has no respiratory disorder, sore hocks, etc. or that she is not too thin. A red vulva is a promising but not infallible sign (80-90 percent chance of mating success). A buck can fertilize a doe with a white vulva (10-20 percent chance of success). When the doe has accepted mounting and the buck has serviced her the breeder removes the doe and puts her back in her own cage. Altogether this should not take more than 5 minutes.
While the doe is being handled the producer can carry out any treatment necessary-anti-mange, for example. If the doe refuses to mate,the breeder can try to present her to another buck. As a last resort he can leave her for 24 hours in the buck's cage but then he cannot be sure that mating has taken place. It is better to mate the animals in the morning or evening, to avoid the hottest hours of the day.
In intensive breeding 1 buck can serve 7 or 8 does. In the extensive system 1 buck can serve 10-15 does. The buck, however, should not be used more than 3 or 4 days a week, and not more than 2 or 3 times a day. So even if there are only, say, 10 does in the unit, there should be at least 2 bucks so that successful mating is not dependent on 1 buck alone. When the size of the unit permits (at least 50 does), 1-2 reserve bucks are kept. If a balanced pelleted feed is used the bucks should be fed from 120 to 180 g a day, depending on their weight.
The first mating of medium-size, properly fed does takes place around 4 months. Bucks are first mated at about 5 months. If production conditions are not optimum the first mating will be delayed until the animals reach 80 percent of their adult weight. There is no advantage in delaying it further. The breeder should carefully supervise the first mating. For the first month the young buck should not be mated as often as an adult.
The only effective way of determining pregnancy is to detect the embryos in the doe's uterus by palpating the abdomen. This operation should be carried out between 10 and 14 days after mating. It is not effective if performed earlier (before the 9th day), while after the 14th day the operation is more delicate and there is a risk of provoking abortion. The breeder must palpate the doe gently and expertly in order not to cause an abortion.
If palpation shows the doe to be empty she is presented to the buck again as soon as possible. Presentation of the doe to the buck as a test of pregnancy is pointless, though not dangerous. Indeed a large proportion of pregnant does accept mating and some empty does refuse. Nor is doe liveweight an indication of pregnancy because weight fluctuations depend on too many factors.
Preparations for kindling (supervision, nest box, changing bedding material, etc) should be made for all the mated does from the 27th to the 28th day after mating if they have not been palpated' but where palpation has been practiced regularly the preparations are restricted to the does found to be pregnant.
A pregnant doe that is not nursing a litter will be rationed if the breeder uses balanced concentrates. The daily ration for medium-size does will be about 150 g. If the doe is nursing a litter at the same time she will be fed ad lib.
Kindling should take place in quiet, hygienic surroundings. The breeder's presence is not required, but the nests should be checked as soon as possible after kindling. This operation is easy and there is no risk to the young. It can be performed right after kindling, provided the mother is removed. The breeder should remove any dead animals, and any foetal sacs the doe has not eaten.
A nursing doe needs considerable nutrition and from the time of parturition she should be fed ad lib. Drinking water is very important in the days leading up to and following parturition. The doe will nurse her young once a day, usually in the early morning.
The mortality rate between birth and weaning is still high (20 percent today in European rabbitries). A mortality figure of less than 12 percent is very difficult to achieve. Therefore the nests have to be inspected daily and any dead animals removed. Strict preventive hygiene is more important than ever at this period.
The breeder may decide it is necessary to eliminate excess newborn rabbits in a large litter. or they may be fostered to a smaller litter, if certain rules are respected:
During the weaning period the young gradually give up milk for solid feed. Weaning is also the time when the breeder separates the young from the doe. All the young of a litter are taken away at the same time and placed 6-8 per cage in the area set aside for fattening. The cages must be clean and the groups should be fairly uniform , with a maximum age difference of 1 week between them. During the transfer operation the breeder checks the health of the young rabbits culling any that are undersized or sick.
Weaning can take place when the rabbit's liveweight tops 500 g (after approximately 26-30 days in rational European production). The young rabbits begin to eat solid feed at 18-20 days, and when they reach 30 days the doe's milk provides no more than 20 percent of the daily feed intake.
One of the apparent drawbacks of intensive reproduction is the rapid turnover of breeding stock. Monthly culling rates of 8-10 percent are not uncommon. In fact, where reproduction is intensive the breeder soon learns the value of each doe and can thus keep the best. The total number of rabbits produced by each doe during her working life is fairly independent of the rate of reproduction imposed by the breeder. Whatever the reproduction and the monthly stock renewal rates, to avoid having empty cages in the nursery there should be a constant reserve of does available that are ready for mating.
The breeder has several means of renewing breeding does. The most practical solution, applicable to both pure breeds and °Common" strains, is to select the best young from the best does. To avoid inbreeding, the bucks and even the does should be obtained from another breeder (selector). If production is intensive, the producer can buy breeding animals from a selection programme of specialized strains for crossbreeding-the system of stock renewal to follow will be advised by the supplier.
FATTENING AND SLAUGHTER
During the weaning-to-slaughter growth period the rabbit should always be fed ad lib. If the breeder uses balanced concentrates, the average daily consumption will be 100-130 g for medium-size animals. In good conditions the rabbits will gain 3(1-40 g a day, which means an intake of 33.5 kg feed will produce a I kg gain in liveweight. Young fattening rabbits can also be fed cereals and fodder, with or without the supplement of a suitable concentrate.
During this period mortality should be very low-only a traction of the fattening stock-but it is often far higher. Preventive hygiene (cleaning, disinfecting) is essential in the fattening station, but the breeder will often pay less attention to this area than he will to the nursery.
The animals are sold alive or as carcasses. Rabbits raised in rational production systems are sold at about 70-90 days at weights of 2.3-2.5 kg for strains like the New Zealand White and Californian. In extensive production systems with less-well-balanced feeding the rabbits may be sold much later (4 to 6 months, maximum). Fattening animals that have passed the usual age for sale can form a reserve from which the breeder can draw for home consumption or stock renewal. In farm rabbitries, the mortality risk from accidents, epidemics and so forth is still high, and any delay in the regular slaughtering age for whatever reason, such as keeping the rabbits alive for gradual home consumption, can end in catastrophe, with the death of all the animals. The higher the mortality rate during fattening, the more the breeder will tend to shorten the length of this production phase.
If rabbits are to be kept beyond 3 months the bucks must be either put in individual cages or castrated, so that they can continue to be colony reared. The females may remain in groups, but will need more cage space than they did before 3 months. Castration is a simple operation, though it usually requires 2 people (Figure 33).
The breeder may wish to slaughter his animals himself. The necessary installations are relatively expensive if the proper standards of hygiene and conservation (cold storage, etc) are to be respected. He will also need labour for a few hours a week to help with the slaughter.
FIGURE 33.-Castration of young male rabbit (Lissot 1974)
Rabbits should be handled gently. They must never be lifted by their ears. Several techniques can be used to pick them up and hold them.
A rabbit can always be picked up by the skin of the shoulders (Figure 34). For animals weighing under 1 kg, one method is to pick them up and carry them by the saddle just above the hindquarters, using thumb and index finger (Figure 35). If the animals are heavier it is best to take them by the skin of the shoulders, but if they have to be transported or shifted for more than 5 or 10 seconds they must either be supported with the other hand (Figure 36) or be carried on the forearm with the head in the bend of the elbow (Figure 37).
If an animal struggles and the producer feels he cannot control it, it is best to just drop it so it will fall on all fours, and then pick it up again correctly within 2-3 seconds. If the breeder keeps his hold on a struggling rabbit he risks some nastry scratches, and can even break the rabbit's backbone.
Organizing a rabbitry
FIRST OPERATION IDENTIFICATION
Identification can be made in 2 ways: by individuals and by cages. The first method is necessary for all producers who intend to select. The second is important for the economic management of the rabbitry.
Each animal is assigned a number. This number will appear on all documents concerning the rabbit and on the rabbit itself. There are 3 main ways of identifying rabbits on a lasting basis. Not all are equally good.
FIGURE 34.-Correct way to pick up a rabbit
FIGURE 35.-Holding a young rabbit head down. The animal is grasped by the back at the haunches
FIGURE 36.-Carrying a large rabbit, supporting its hindquarters
FIGURE 37.-Technique of carrying a rabbit on the forearm
FIGURE 38.-Using a clipper with movable numbers to tattoo the identification number on a rabbit's ear (1 = operator's hands, 2 = assistant's hand)
The management unit of a rabbitry is the mother-cage. All the cages in the nursery section should be numbered, and this is the figure that will appear on the records. This method is much easier than individual identification, so it is used in rabbitries which keep records but do not breed selectively.
An identification system is essential even in small rabbitries. It will form the basis of the technical records that will serve for both the organization of the work and the economic management of the rabbitry.
FIGURE 39.-Example of a doe card.
FIGURE 40.-Example of a buck card. M = mating, P = outcome of palpation, NL = number of rabbits born live
TECHNICAL RECORDS AND ORGANIZATION OF WORK
This unit will occupy most of the producer's attention.
A daily record book is essential in almost every kind of production. The producer notes the chief operations simply and clearly:
The young does selected for replacement are identified at weaning.
This list is far from complete. Litter weight at weaning could be added, for instance. If the producer uses balanced concentrates he will enter the amounts fed in the nursery to compute the average feeding cost per weaned rabbit. This is an important item in calculating net profit. A similar entry would be equally helpful for other types of feeding, but these are far more difficult to estimate.
The record book system is often inadequate. One improvement is a doe card hooked to each cage, for calculating individual doe productivity. The example shown in Figure 39 summarizes the items of information just listed. Another useful addition is a buck card (Figure 40).
The next step is to put the data together to get an overview of the unit for efficient organization of the work. This is essential in any rabbitry with more than a few dozen does.
Planning pigeonholes (Figure 41) offer a virtually foolproof way of monitoring all events in the nursery. Assuming that does are remated and litters are weaned no later than 1 month after kindling, the system involves a large box with 4 horizontal rows of 31 compartments. Each corresponds to a day of the month. The first row is for matings, the second for pregnancy checks (palpation), the third for births and the last for weanings. If weaning takes place between 1 and 2 months, which is common in extensive production, there will be 2 rows for weaning, for even months and odd months.
FIGURE 41.-Diagram of planning pigeonholes (see text for explanation of card movement)
Every morning the producer sees in his work book what operations are to be carried out. As each is completed, the card of the doe concerned is moved into the pigeonhole corresponding to the next operation and the day for which it is scheduled.
In a rabbitry where mating takes place 10 days after kindling and rabbits are weaned at 35 days, the doe record could be as follows: Let us suppose the doe is mated on the third day of an odd month. Her card is then placed in the palpation row. This operation is performed on the 16th of the same month ( + 13 days). If the result is positive, the doe card is placed in the kindling row under the second day of the following month (+ 15 days). If it is negative, her card will go back to the mating row. After kindling the doe card returns to the mating row under the 1 2th day of the same month ( + 10 days). At the same time, a card with the doe's individual and cage numbers will be placed in the weaning row, in space , of the second, odd month (+35 days).
There are other planning systems. The important thing is to use one system consistently.
Scheduling several matings, a few palpations and the weaning of several litters all for the same day adds up to a lot of wasted time. Using a weekly work plan I man working 8 hours a day can manage 250-300 does. Table 52 is an example of such a work plan. Scheduled matings (Thursdays and especially Fridays) mean other activities can be grouped (weaning on Tuesdays, palpation on Wednesdays). Some activities such as nest supervision and feeding have to be carried out every day.
With this method batches of litters at weaning are close to the same age. It also sets the time for activities the producer always tends to postpone, such as recording data and carrying out preventive hygiene measures.
In a rational production unit the following average times must be set aside for the main nursery activities for 100 does:
mating: 4 hours a week;
TABLE 52.-EXAMPLE OF WEEKLY WORK PLAN
|Numbering kindlings and first check||X||X|
|Weaning young and first selection of future breeding animals||X|
|Culling sick and unproductive females||X||X|
|Filling in doe cards||X|
|Second selection of future breeding animals at 70 days||X|
|Cleaning equipment and building||X||X|
|Health inspection of animals and nesting boxes||X||X|
|Palpating does mated 2 weeks earlier||X|
|Mating of females that kindled the previous week and does empty when palpated||X||XX|
|Setting up nest boxes||X|
|Filling in buck cards||X|
|Routine activities (supervision, feeding)||XX||XX||XX||XX||XX||XX||X|
X = Operation to be performed on day marked.
Here again the daily record book is essential. It will list the first and last fattening days (sale or slaughter) of the animals in each cage, any mortality and the apparent causes. Liveweight when sold and the number of animals marketed weekly could also be added. In large-scale production, production checks will be done by batches (a batch is a group of rabbits weaned the same week). The batch will be the core reference point of all technical data.
If the breeder uses balanced concentrates he will record the amount of feed eaten by fattening rabbits. Feed conversion efficiency (the amount of feed needed to produce a weight gain of I kg) is a sound economic criterion. If the producer wants to breed his stock selectively he can use a litter card listing the weaning weight and date, the weight and date at sale or slaughter, and the individual identification number of each rabbit.
TABLE 53.-REPRODUCTION DATA FROM 100 RATIONAL PRODUCTION UNITS MONITORED FOR TECHNICAL MANAGEMENT. IN FRANCE. 1980
|Criteria||General average||Coefficient of variation (%)1||Average of 9 best performances 2||Average of 9 poorest performances 2||Average performance of 9 most productive units|
|Number of does per buck||8.4||20||-||-||7.8|
|Kindlings per mating (%)||67||15||81||49||75|
|Average period between kindlings (days)||53||19||42||75||43|
|Live births per kindling||7.9||8||8.9||6.6||8.2|
|Number weaned per weaned litter||7.1||8||8.1||6||7.5|
|Percentage of litters not weaned||10||55||3||20||7|
|Percentage of birth-weaning mortality||17.6||32||10.4||28||13.9|
|Culling rate of female stock(%)||112||34||-||-||126|
|Age at weaning (days)||29||10||-||-||28|
|Average weight at weaning(kg)||0.603||19||-||-||0.589|
|Number of young weaned per doe mated per year||47||20||61||29||59.8|
SOURCE: Koehl, 1981.
1 Coefficient of variation = ratio of standard deviation of the population from the mean, expressed as a percentage of the latter.
2 The data in each line are not necessarily from the same 9 units as those in the following line.
Table 53 contains the findings of a sample study made in 100 rational French production units. The production units used for estimating the average of the 9 best or 9 poorest performances for the different criteria listed are not necessarily the same.
The basic technical criterion in the nursery is the number of young weaned per doe per year. Economically, the tendency is to calculate this in terms of the mother-cage and include the amount of feed consumed. The young weaned per doe depend on the number of kindlings a year, the number of young weaned per litter and the real rate of occupancy of the nursery cages.
Several analytical factors are important in the fattening stage- growth rate, feed efficiency, age at slaughter, carcass yield, mortality. Global criteria such as overall feed efficiency (number of kg of feed from birth to slaughter needed to produce 1 kg of rabbit) cover the range of production and feeding activities. The number of rabbits sold per week in reference to a fixed number of does is another global criterion.
To help producers with this work, outside organizations (research or development agencies, private firms) can collect the main technical data of their production units every week and make an estimation of these parameters. With this information a breeder knows what results to expect. A comparison with other rabbit production units will reveal any weak points in his system.
As with keeping technical records, not all producers have the same needs in economic management, which mainly concerns those whose purpose is to make a good profit.
There is a great deal of variation in this area. Results depend on the expertise of the breeder and his economic situation, so there is not much point in giving absolute figures. Table 54 shows the relative importance of the various items on a French breeder's cost schedule. He is an average producer who started a year ago with 100 breeding does in a new building. His investment per mother-cage is sizeable but not excessive. His productivity level is 46 young rabbits marketed per mother-cage per year at 2.4 kg. The overall feed efficiency index is 4. His does are hybrid breeding animals. The annual culling rate is 80 percent. The ratio between the sale price of 1 kg of live rabbit and the cost price of the feed is 8 to 1.
TABLE 54.-COST SCHEDULE (MINUS LABOUR) IN A RATIONAL FRENCH PRODUCTION UNIT
|Heating, water, electricity||5.6|
|Amortization of breeding animals||2.5|
|Insurance and miscellaneous||1|
|Medium-term financial charges||4.2|
SOURCE: Koehl, 1982.
NOTE: For this same year the cost price, 2 to 5 percent lower than the sale price, broke down as 25 percent labour costs and 75 percent nonlabour costs.
TABLE 55.-INFLUENCE OF VARIOUS FACTORS ON INCOME OF A FRENCH PRODUCTION UNIT
|Factor||Relative variation||Relative income increase|
|Sale price of 1 kg of rabbit, liveweight||+10||+70|
|Purchase price of 1 kg of feed||-12.5||+40|
|Number of young rabbits sold per mother-cage||+ 22||+ 70|
|Interval between kindlings||- 8||+23|
|Birth-weaning mortality||-35||+ 23|
|Global feed efficiency||-12.5||+34|
Source: Surdeau and Henaff, 1981.
Note: These results relate to French conditions. The various factors are interlinked and cannot, therefore, he added. Figures are indicative.
Operating costs, which can vary with the production system, here amount to more than 70 percent of the cost of production. Feed is the main item under this heading (65 percent of the total outlay). This is why feed efficiency is so important. Depreciation of the building and equipment together with financial charges amount to more than 25 percent of the total. These figures are closely linked with the French socioeconomic situation. As always, the higher the level of investment the greater the unit's productivity must be to write off these debts.
Table 55 looks at the influence of various production factors on income. The same 100-doe unit mentioned above was used for this study. The findings are indicative and valid in French conditions for production levels close to those in Table 53. Among the financial factors, sensitivity to sale prices for rabbit meat is very high. In these circumstances it is easy to see the advantage of direct sales.
Improvement in overall production has a substantial impact on producer income. Feed consumption is here again of considerable importance.
Contents - Previous - Next