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.
As ovulation in does is induced 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 one or two litters a year under the most extensive management to eight to ten litters in an intensive management system. In rational European rabbitries does are remated either immediately after kindling (intensive system) or about ten days later (semi-intensive). European backyard rabbitries use a more extensive system, presenting the doe to the buck one or two months after kindling. Young does are first presented for mating at four to seven months, depending on the breed (lighter breeds are usually more precocious) and, especially, on the diet.
In the semi-intensive system illustrated in Figure 38, the does are first presented to the buck at four and a half months. They are then mated 10 to 12 days after the birth of each litter. Weaning takes place at 30 to 35, or even 37 to 38 days. Many European breeders (France, Italy, Spain) used to practise the intensive system: mating does within 48 hours of kindling and weaning the young at 26 to 28 days. This, however, requires very good feeding and a producer with a fairly high level of expertise and was gradually abandoned during the 1980s.
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 practised in France in farm rabbitries, where breeding does are fed fodder and grain.
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 one month, the fattening period is seven weeks. The rabbits weigh 2.3 to 2.4 kg (live weight) when they are ready for the market. Some African breeding units where weaning takes place at two months are reported to need a four-month fattening period, because balanced feeds are not available. European and North American countries which market rabbits at live weights of 1.7 to 1.8 kg use a different system. The young are not weaned. They are left with their doe up to the age of two months, when they are sold. The mother is remated three weeks before that. This system can produce five or six litters a year. In Spain, however, at a highly comparable sales weight of 1.8 to 2 kg live weight, rabbits are weaned at about one month, then fattened for only one month more. These breeders are actually using the semi-intensive reproduction rate to obtain a great many kindlings and hence more rabbits per doe each year.
FIGURE 38 Production cycle of the domestic rabbit
Mating. 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 to 90 percent chance of mating success). A buck can fertilize a doe with a white vulva, but the success rate is only 10 to 20 percent. 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 five 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 leaving her for 24 hours in the buck's cage but then 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. Some breeders in France practise double mating. This means that the doe is mated twice in succession at intervals of 10 to 15 minutes, either by the same male or by two different males. A similar technique is to leave the female in the male's cage for 15 to 20 minutes after mating has first taken place. These techniques allow a slight increase in the percentage of pregnant does (4 to 6 percent, roughly). The drawback, however, is that it considerably increases the number of matings per male and in this system no male can be mated to more than two females each week without jeopardizing the outcome through over exploitation of the buck.
In intensive breeding one buck can serve seven or eight does. In the extensive system one buck can serve 10 to 15 does. The buck, however, should not be used more than three or four days a week, and not more than two or three times a day, which means no more than six ejaculations per week. So even if there are only, say, ten does in the unit, there should be at least two bucks so that successful mating is not dependent on one buck alone. When the size of the unit permits (at least 50 does), one or two reserve bucks are kept. If a balanced pelleted feed is used the bucks should be fed from 120 to 180 g per day, depending on their weight.
The first mating of medium-size, properly fed does takes place around four months. Bucks are first mated at about five 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.
Determining pregnancy. 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 ninth 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, if the breeder mates the animals every day in the week. But if the breeder practises group rearing or cycling (paced by the week), he or she will represent the doe to the buck (or use artificial insemination) two to three weeks after the non-productive mating. If the rabbits are merely raised as a group, however, with all does in the production unit at the exact same stage of reproduction (in this case only artificial insemination is used), an empty doe will simply be marked for the appropriate feeding (and perhaps housing) for her situation. She will be reinseminated only with the other does in the production unit. 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 live weight 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 practised regularly the preparations are restricted to does found to be pregnant.
A pregnant doe that is not nursing a litter will be rationed if the breeder uses pelleted feed. The daily ration for medium-size does will be about 150 g (35 to 40 g/kg live weight). If the doe is nursing a litter at the same time she will be fed ad lib.
Kindling. 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 (15 to 20 percent today in European rabbitries). A mortality figure of less than 10 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.
Fostering. 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:
Where a production unit is big enough, and particularly where the breeder practises group rearing, systematic fostering is recommended to achieve equal litter size. The ideal size for withdrawal/fostering is average litter size at kindling (or somewhat smaller if there is a feeding problem). Where there are too many young rabbits the chances of survival are poor and, if young rabbits are to be culled, the lighter ones should be chosen.
Weaning. 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. The breeder may opt for one of the two following weaning methods: all rabbits in the litter are withdrawn at the same time and placed six to eight per cage in the area set aside for fattening. Alternatively, the doe may be removed from the cage and the young rabbits left, a method which reduces postweaning stress for the young rabbits but does necessitate the right production equipment. Management must be geared to group rearing. If the young rabbits are moved (still the more common system), the cages must be very clean and the litters should be kept together, if possible, for uniformity. The alternative is same-age cages (maximum age difference one week) with all rabbits put in the cage the same day. Rabbits soon establish a social hierarchy in the cage and any new introduction is a source of conflict. 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 live weight tops 500 g (after approximately 26 to 30 days in rational European production). The young rabbits begin to eat solid feed at 18 to 20 days and at 30 days the doe's milk provides no more than 20 percent of the daily dry-matter intake. Practically speaking, young rabbits benefit from late weaning until the age of six weeks. Depending on the rate of reproduction chosen, weaning should take place no later than two or three days before the doe's next kindling: e.g. 28 days for postpartum fecundation to 38 to 39 days for fecundation taking place 11 days after kindling (42-day rate).
Stock reduction and renewal of breeding does. One of the apparent drawbacks of intensive reproduction is the rapid turnover of breeding stock. Monthly culling rates of 8 to 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 "ordinary" 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 cross-breeding - the system of stock renewal to follow will be advised by the supplier.
Renewal mainly takes the following two forms:
Whatever the genetic type of rabbits brought into the establishment for the renewal of breeding stock, they should be brought in at a fairly early age. INRA's research shows the best solution to be day-old rabbits. This method, proposed in 1987, was soon adopted by French breeders. The future breeding rabbits are immediately fostered by does with good maternal aptitude in the establishment. The young rabbits adapt much better than those introduced at the age of eight to 11 weeks, and particularly four months or older. The rabbits nurse only once in 24 hours, leaving an entire day for their transfer from the selection centre to the rabbitry. This has even been extended to 36 hours to allow the day-long and problem-free transfer of rabbits from the west coast of the United States to France.
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 to 130 g for medium-size animals. In good conditions the rabbits will gain 30 to 40 g a day, which means an intake of 3 to 3.5 kg feed will produce a 1 kg gain in live weight. 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 fraction of the fattening stock - but it is often far higher. Preventive hygiene (cleaning, disinfecting) is essential in the fattening station, but the breeder is often inclined to pay less attention to this area than to the nursery.
The animals are sold alive or as carcasses. Rabbits raised in rational production systems are sold at about 70 to 90 days at weights of 2.3 to 2.5 kg for strains such as the New Zealand White and Californian. In extensive production systems with less well-balanced feeding the rabbits may be sold much later (four to six 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 disaster, 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 three months the bucks must either be 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 three months. Castration is a simple operation, though it usually requires two people (see brief description in Figure 39).
Breeders may wish to slaughter their own animals. The necessary installations are relatively expensive if the proper standards of hygiene and conservation (cold storage, etc.) are to be respected. Staff who will work only a few hours per week are also needed.
Rabbits should be handled gently. They should be lifted by their ears as little as possible. Several techniques can be used to pick them up and hold them.
FIGURE 39 Castration of young male rabbit
A rabbit can always be picked up by the skin of the back (Figure 40). For animals weighing under one kilogram, one method is to pick them up and carry them by the saddle just above the hindquarters, using thumb and index finger (Figure 41). If the animals are heavier it is best to take them by the skin of the back, but if they have to be transported or shifted for more than five or ten seconds they must either be supported with the other hand (Figure 42) or be carried on the forearm with the head in the bend of the elbow (Figure 43).
If an animal struggles and the producer feels he cannot control it, it is best just to drop it so it will fall on all fours and then pick it up again correctly within two or three seconds. If the breeder keeps his hold on a struggling rabbit he risks some nasty scratches and can even break the rabbit's backbone.
First operation: identification
Identification can be made in two 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.
FIGURE 40 Correct way to pick up a rabbit
FIGURE 41 Holding a young rabbit head down
Individual identification. Each animal is assigned a number. This number will appear on all documents concerning the rabbit and on the rabbit itself. There are three main ways of identifying rabbits on a lasting basis; not all are equally good:
Cage identification. 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 for selection purposes.
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.
Technical records and organization of work
In the nursery. This unit will occupy most of the producer's attention. A daily record book is essential in almost every kind of production. In large European production units, most of this information is now computerized. The producer notes the chief operations simply and clearly:
FIGURE 42 Carrying a large rabbit, supporting its hindquarters
FIGURE 43 Technique of carrying a rabbit on the forearm (Calm animal)
FIGURE 43 Technique of carrying a rabbit on the forearm (Agitated animal)
FIGURE 44 Using a clipper with movable numbers to tattoo the identification number on a rabbit's ear
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 feeds the amounts fed in the nursery will be entered 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 45 summarizes the items of information just listed. Another useful addition is a buck card (Figure 46).
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 47) offer a virtually foolproof way of monitoring all events in the nursery. Assuming that does are remated and litters are weaned no later than one month after kindling, the system involves a large box with four 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 one and two months, which is common in extensive production, there will be two rows for weaning, for even months and odd months.
FIGURE 45 Example of a doe card
Every morning the producer sees in the 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 ten days after kindling and rabbits are weaned at 35 days, the doe record could be as follows: 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 12th 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 7 of the second, odd month (+35 days).
There are other planning systems. The important thing is to use one system consistently. Computerized individual performance records can combine these parameters and list the daily operations to follow in line with the management model adopted by each breeder, listing the history of each breeding animal.
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 one person working eight hours a day can manage 250 to 300 does. Table 56 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).
FIGURE 46 Example of a buck card
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.
This weekly management plan, used for nearly 30 years, has expanded into age-group rearing or cycling as described above. At first all rabbits of the same age were grouped in the same part of the rabbitry (hence the term age group). Next, breeders kept same-age rabbits only in the same rearing unit. Each unit was cleaned and disinfected after the rabbits were sold or put in a newly cleaned unit. This means breeding does move regularly from one unit to another at each weaning (hence the term cycling).
Age-group rearing quickly led to rabbit production units organized into just three age groups at intervals of two weeks or two age groups at intervals of three weeks, with a semi-intensive "42-day" rate of reproduction in both instances, and fecundation by natural mating or artificial insemination. In the last two or three years, some Italian and French breeders have been working with a single age group: all does in the establishment are fecundated on the same day by artificial insemination only once every 42 days.
These different management techniques have basically evolved to reduce the amount of labour per rabbit, even though productivity per female is not as high as is theoretically possible.
Fattening records. 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. Live weight when sold and the number of animals marketed weekly could also be added. In large-scale operations, 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.
FIGURE 47 Diagram of planning pigeonholes
If the breeder uses balanced concentrates he or she will record the amount of feed eaten by fattening rabbits. Feed conversion efficiency (the amount of feed needed to produce a weight gain of 1 kg) is a sound economic criterion. If the producer wants to breed stock for selection purposes a litter card is used listing the weaning weight and date, the weight and date at sale or slaughter and the individual identification number of each rabbit.
Working hours. In a rational production structure under European production conditions, some 12 to 20 working hours per week per 100 does that are actually producing is the rule. Same-age rearing in a well-organized establishment can even reduce this to under ten hours. Indicatively, listed below are average working times per week in 1991 in a group of 18 rabbitries in southeastern France, each for 100 producing does and their progeny (GELRA, 1991).
TABLE 56 Example of weekly work plan
Table 57 shows the performance records since 1983 of selected French rabbitries monitored under technico/economic management. It covers more than 1100 production units for the last year. The parameters change little from one year to the next.
The main productivity criterion is the number of progeny per breeding doe per year. The average here is 46 young rabbits for the year 1992. Strikingly, the range of performance around this mean is great: in the 275 most productive units (the top quarter), the output was 58.7 young rabbits sold per doe. The yearly renewal rate of does of 131 percent means that in order to maintain 100 breeding females year-round, 131 new does must be introduced each year, i.e. the average productive life of a doe is just over nine months (365 days ÷ 1.31 = 279 days) between the first mating and withdrawal (culled or dead).
Basically, the average production per doe depends on the theoretical breeding rate set by the breeder (in France the doe is presented to the male eight to ten days after kindling), the ratio of kindlings to mating (73.3 percent in 1992), litter size at birth, and the survival rate of newborn rabbits.
TABLE 57 Annual production performance in France from 1983 to 1992 in rabbitries monitored under technico-economic management
A further 25 percent of these rabbits are lost before sale. Technically, the range is also great here, with the best breeders selling a little over 90 percent of their liveborn rabbits.
Economically, the consumption index is a major item. Under French conditions, feed accounts for over 50 percent of all production costs, including labour. In 1991 for the first time, breeders spent a little over 4 kg feed to produce 1 kg of rabbit for sale, including the feed consumed by rabbits sold, breeding does, bucks and replacement breeding animals. In different economic conditions the portion of feed cost price may vary, but it is always the major expense item.
Various external agencies (research or development agencies, private firms) may collect weekly data on production performance and evaluate the parameters for the purpose of helping breeders collect and analyse these technical criteria, keeping the breeder abreast of performance at all times. Computer programs can provide the same information at the production-unit level, but regular comparisons with other rabbitries will highlight weak points for the breeder.
As with keeping technical records, not all producers have the same needs in economic management, which mainly concerns those whose purpose is to make the maximum profit.
There is a great deal of variation in this area. Results depend on the expertise of the breeder and his or her economic situation, so there is not much point in giving absolute figures.
Table 58 shows the relative importance of the various cost items for a group of 18 French breeders followed in 1991. Figures are given in percentage of turnover.
TABLE 58 Cost schedules in French production units as a percentage of annual turnover: averages and values for the upper and lower thirds of rabbitries classified by doe productivity
TABLE 59 Influence of various factors on income of a French production unit
To indicate variability, figures are also given for the six least-productive rabbitries (37 progeny per doe per year) and the six most productive rabbitries (over 54 progeny per doe per year). A major expense item, as stated, is feed purchases. Depending on productivity, the share of turnover used to pay wages ranges from 19 to 29 percent, even though the rabbitries in the study lie in the same French region and are thus economically comparable in terms of feed purchase price and rabbit sale price.
As always, the higher the level of investment the greater the unit productivity needed to write off these debts. Productivity should be expressed either as unit of investment or as working time, depending on which is the main local constraint.
Table 59 looks at the influence of various production factors on income. The findings are indicative and valid in French conditions for production levels close to those in Table 57.
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. Careful selection of genetic type will increase profits by increasing litter size under specific breeding conditions.
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