Methods and age of reproduction of nutria
In the cold winter, nutria face many troubles. So one of our readers, despite the fact that he has been “tinkering,” as he wrote, with nutria for 4 years, has not achieved success. Either the puppies are born dead, or the mothers themselves brutally deal with their offspring. In addition, the author of the message does not have information about whether to give water to animals in winter or whether it should not be done.
What causes dead babies to be born in nutrias? Why do nutria kill their babies?
What is relevant to the 1st question is that under satisfactory feeding and breeding conditions, nutria are less likely to give birth to dead babies or gnaw them to death. Very often, nutria puppies die from cold in the first hours after birth (they are mistaken for stillborn).
In the cold season, during whelping, the temperature in the house with bedding material should not be lower than plus 10-15°. An uninsulated shed becomes a disastrous place for young animals. Either the shed needs to be heated, or the female must be transferred to another, warm room for 7-10 days during whelping. 2-3 days after birth, the insides are no longer dangerous from cold and snow.
Should I give water to nutrias in winter or not?
It is also possible not to give them water to drink, but in this case it is imperative to moisten the feed, bread crusts and feed root vegetables - beets, carrots, etc. In the warm season, water for drinking and bathing is simply a must.
How to feed pregnant nutria. Concentrated juicy or mixed type of feeding of nutria. Concentrated succulent or mixed type of feeding presupposes the presence in the diet of both concentrated feed (grains and legumes and their processed products, products of animal origin) and succulent feed.
To produce one nutria skin and 2-2.5 kg of meat with 6 puppies per female per year, the following feed is consumed: compound feed or cereal grain - 44 kg, protein feed of plant and animal origin - 6 kg, grass meal - 6 kg, root vegetables or vegetables - 30-50 kg, legumes and cereals - 30-50 kg, litter - 10-15 kg.
Crucial periods in feeding nutria are mating, pregnancy, lactation, and raising young animals. At this time, it is necessary to especially ensure that the feed is complete and satisfies the physiological needs of animals for nutrients.
Feeding nutria during mating.
In nutrias, there are no noticeable physiological needs for food during this period: during lactation, the female can go into mating or be pregnant. During the mating period, breeding males are fed the same rations as females, with the only difference being that they are given 20-30% more food, since they are larger than females and more active - dopinfo.ru. By the time of mating, both adult and young females should not be obese, which is observed when animals are overfed or have low mobility. Overly plump males are inactive, and females are poorly covered and fertilized.
Feeding pregnant female nutria.
Significant changes occur in the body of females during pregnancy, which are associated with the formation and growth of embryos, amniotic membranes, enlargement of the uterus and mammary glands. This requires additional nutrients and energy. During the period of mating and pregnancy, young females continue to grow and therefore eat 10-15% more food than adults. But adult pregnant females need nutrients to a greater extent than young ones, since they are much larger, so a diet balanced in basic nutrients for them should consist of easily digestible food, since nutria cannot consume a large amount of food.
An approximate diet for young pregnant females aged 8-11 months could be: beets in winter or grass in summer - 270-350 g; concentrates (barley, corn) - 120-170 g; cake, peas - 5-10 g; fish meal - 4-8 g; table salt - 1.5 g; hay or grass flour - 25-30 g; fish oil - 2.5 g.
After palpating the females and establishing pregnancy, they are transferred to the diet for the second half of pregnancy. During this period, in adult and young females, the need for food increases by 15-30%, and at the same time, motor activity decreases, especially in cages without pools, which helps to increase the fatness of females - dopinfo.ru. When the female is overfed, the embryos in the womb are inactive, few in number, and born large (350-500 g each), but sluggish. Therefore, as soon as the female begins to gain weight, it is necessary to reduce the amount of total food by 25-30% or increase the amount of difficult-to-digest food in the diet (by 15-20%) or green food (by 30-35%). Animal feed should contain 3-5% calorie content.
In the autumn-winter period, it is advisable to introduce fish oil into the diet of females as a source of vitamin A, the lack of which leads to the birth of blind puppies or they become blind 1-2 weeks after birth.
Feeding females and sucklings
Before whelping (2-3 days) and in the first days after it, females hardly eat. When food is consumed according to the appropriate standards, the live weight of females during the lactation period is reduced by 5-10%. The level of feeding of lactating females should be aimed at producing the greatest amount of milk by the mammary glands, since the first 10-15 days of the puppies’ life depend on the milk production of the females. Nutria milk is highly nutritious due to the large amount of fat it contains, and it is completely digestible by puppies.
On average, one puppy consumes mother's milk per day: in the 1st decade - 16 g; in 2 - 22-26 g; at 3 - 18-22 g; at 4 - 16-24 g; at 5 - 6-8 g; at 6 - 0-4 years. If there is not enough milk, the puppies are stunted in growth and it happens that they die 5-7 days after birth.
From 10-15 days, puppies can be raised on adult nutria food. In addition to mother's milk, puppies from 2-3 days try a mash of mixed feed and root vegetables; on the 3-4th day they appear original feces (meconium) in the form of dark green threads, and from the 5th-6th day - real feces (small gray-brown sticks - dopinfo.ru); With age, feces take on the shape of oval balls. In the first 15-20 days of lactation, the female eats 85% of the food, and on days 40-55 the female and all puppies consume food equally. Lactation in females ends on day 40-45, at which time the puppies are completely fed concentrated and succulent food. In summer, lactating females and suckling puppies are given green mass (10-15% in calorie content). When using concentrated feeding, there must always be clean water in the cage for drinking.
Nutria reproduction is very similar to rabbit reproduction, i.e. they reproduce almost throughout the year. Just like in rabbits, females can combine pregnancy with lactation.
It is not difficult to determine what gender an individual is. In females, the genital slit is located near the anus. In males, the genital organ is several centimeters away from the anus. The testes of males are often located in the body, and sometimes descend through the inguinal canals and can be felt.
At what age can it happen?
If the animals were kept correctly and were provided with proper care, then nutria become sexually mature by five months. At this age, males become more active and are ready to fertilize females, but it is too early to conceive at this age. In females, the desire to mate is repeated approximately every 25 days and lasts approximately one and a half days. Experienced nutria breeders practice nutria breeding, which involves whelping females twice within one year, in the 1st and 3rd quarters. Mating is carried out during the periods from the end of summer to the end of autumn and from the end of winter to mid-spring.
The sex and age structure depends on the practiced method of breeding these animals and the size of the population. For five to eight females, one male is enough if mating is carried out using the transfer method. In the case of family keeping, as many females will require two or three males. Mating involves a ratio of males to females of one to fifteen or even twenty. Usually one female is used for breeding for two years. But if all breeding standards are followed, then females are able to bear good offspring and raise healthy babies up to the age of four. But due to culling for various reasons, the number of such females is limited.
The age of the females is extremely important. It is not recommended to breed females before six to eight months of age. Males up to seven to nine months of age. The mass of individuals should be about four kilograms.
If you take younger females for mating, then, as a rule, their fertility will decrease; the offspring will be small in number with a large number of dead babies. Survivors are usually very weak and do not gain weight well. If a male is introduced to females early, then very often they become accustomed and they do not cover the females well.
If mating is delayed, the females, as a rule, become fat very quickly and are poorly fertilized. Mating technologies largely depend on how old the females are. Young females are usually fertilized in schools. A group is formed from the released young individuals, two to three months old. When forming, one must take into account their development and from which individuals they were obtained. They are raised collectively.
When females reach the required age, i.e. After six to eight months, a male can be added to them. Must be unrelated and have been tested for sexual activity. The size of the school depends on the size of the place where they are kept. The maximum size of a school if a young male is added is fifteen females; an adult male can be placed with twenty females.
Area required for transfer mating, manual mating, combined mating and family mating
The recommended size of the housing area for one individual in small schools (up to five heads) is easy to determine - 0.28 m2. If there are many females in the school, especially individuals of the older age category, then the area per individual should be increased to two square meters. This is necessary to prevent injury to animals. Sometimes, after the addition of a male, fights occur between females, especially if there are pregnant individuals in the group. The increased area makes it possible to exclude encounters with individuals showing aggression.
The increased area during shoal mating is especially important. Older individuals who have completed lactation are considered the most aggressive. To minimize the number of injuries, it is advisable to create groups of females for mating from those whose babies were separated several weeks ago. In this case, the male is hooked on the same day. Taking these points into account, in private farms females who have whelped sometimes do not use the herding method, but the replanting method, or they practice family keeping. If manual mating is practiced, the female can be placed with the male within three days after giving birth. Then for seven days every twenty-four days after whelping. After covering the female with the male, she needs to be placed next to the male the next day. In the case of this method of mating, the female can be fertilized in the 1st or 2nd heat. In this situation, she will be pregnant while feeding the babies.
In the 3rd estrus, from approximately 48 to 62 days after whelping, you can proceed to mating of individuals not covered in the 1st or 2nd estrus. It is also necessary to place a male with females whose pregnancy has not been determined on the fiftieth day after mating. Combining pregnancy and lactation is not recommended, since the animal is exhausted and females are placed with males during another estrus. In order not to miss the time of estrus, a schedule must be drawn up for all females, which will indicate the time of transferring her to the male.
To reduce labor costs during mating, during feeding and laying bedding, and to reduce the amount of space occupied by individuals of the main herd, family breeding is practiced, which involves the constant maintenance of one male with three or five females. To form a family, you can use both related and unrelated females that were raised together. When they reach six to eight months of age, an unrelated male can be placed with them. This family can be preserved throughout the entire breeding period. This method of maintenance also has some disadvantages, for example, the high mortality rate of babies as a result of trampling by adults. Also, in the case of simultaneous whelping of several females, it is very difficult to determine the parents of the babies.
A combined mating scheme is also practiced. For example, lactating individuals can be bred using the transfer method, and after dropping the puppies in schools or males, they are used not with just one female, as during family breeding, but with several. At the same time, he sits down one by one for about fifty days.
During mating, it is necessary to constantly inspect the males, because very often, due to the loss of the genital organ or the appearance of a hair ring, it becomes incapable of covering the female.
Pregnancy and childbirth
The duration of pregnancy in nutria usually lasts 132 days. You can determine whether a female is pregnant or not by feeling the presence of embryos in the uterus. They are usually freely detected from the fiftieth day.
Video “Nutria gives birth”
This video shows how nutria gives birth.
During the check, the female should be held by the tail (the front legs rest on a support), and the presence of embryos should be felt through with the other hand. With a fifty-day pregnancy, the size of the fetus is about two centimeters. The nipples of female nutria are not on the abdomen, but on the sides. This placement of the nipples protects them from injury and contamination during the movement of animals, and in the wild it allows babies to suckle from their mother, who is in a shallow body of water. In young individuals that have not yet been fertilized, the nipples are practically not palpable. After a month and a half of pregnancy, they increase significantly, and already by this sign it is possible to determine whether the female is fertilized or not.
If the animals were properly kept and fed, childbirth occurs easily and healthy puppies are born.
Nutria usually give birth at night or early in the morning. There is usually no need for human intervention. The average litter is 5 babies, but from 1 to 17 can be born.
Caring for newborns
Innards are born with open eyes, teeth and covered with hair. The weight of newborns is 80-380 grams. In the summer, females whelp and safely feed their cubs on a mesh with a mesh size of 16 x 48 millimeters. In this case, there is no need for bedding, but the ambient temperature should be above + 15°C. If the temperature is lower, then bedding is needed. If the temperature is below plus five degrees, then even thick bedding may not save newborns, since they are born wet and this may end in their death. At sub-zero temperatures, the female should give birth in a heated room.
A few days after birth, puppies can move freely, explore the cage, and swim in the warm season. They can also easily find food and are able to tolerate temperature drops down to -10°C. After the female whelps, remove the afterbirth from the cage. In some cases, the female eats it. Also, if there are dead puppies, they must also be removed from the cage. If the litter gets wet, change it to dry. If many puppies were born, for example more than eight, then some can be transferred to other females who have a small litter.
What to do if a lactating female is unwell
Lactation of female nutria lasts up to two months. If the amount of milk is normal, then the babies have normal growth and there is no need to examine the female. If the babies grow poorly, are inactive, and the fur is dull and disheveled, then the female needs to check the condition of her nipples and mammary glands. If they have a flabby appearance and if you press on them there is little or no milk at all, then this indicates that not everything is fine with the mother’s health. In such a situation, you should try to place the babies with other females. The babies are placed in the stepmother's nest, having first removed her for 40 minutes and after that they are allowed near the babies.
Dropping off babies and creating groups
Grown-up chicks can be removed at the age of fifty days. A sign must be attached to the cage or house in which the babies are located, on which it is imperative to note the color type, the number of the female from which they were obtained and the size of the litter.
After three months, babies can already be marked and sorted by gender. Then you can move on to assembling groups for further cultivation. Groups are formed from individuals of the same sex and approximately similar in development. This makes it possible to eliminate differences in growth between young animals and prevent fights between them when kept together.
Males that differ in origin and color can be combined into one group, even if it is planned to use all of them or only some of them in breeding work. It is not difficult to choose a male suitable for subsequent reproduction on your own. Groups of females destined for slaughter are organized using the same scheme. In the group of females that you leave for further reproduction, their color and origin must be taken into account. In the case of a large population, a group of females can be formed from individuals of the same color. It may also include related individuals. With this approach, it is easier to select for them an unrelated male of a suitable color type in order to obtain more cubs with the required color.
This video shows how one-day-old nutria babies behave.
PREGNANCY AND PUBLICATION OF FEMALES
Definition of pregnancy. Effective low-intensity methods for determining nutria pregnancy at an early stage have not yet been developed. In practice, nutria pregnancy during this period is determined by experienced nutria breeders by the appearance of the female, the condition of the nipples and the relationship of the female to the male.
Indicators of a female's pregnancy can also be an increase in her weight as a result of fetal development. In an adult female, during the last 2 months of pregnancy, the weight increases by 1-1.5 kg. Pregnancy can be more accurately determined by palpating the lower abdomen. To do this, the female caught by the tail is given the opportunity to rest her front paws on the roof of the house or on the upper part of the paddock, her hind paws should be freely lowered. With one hand they hold the nutria by the tail, the other is brought under the abdomen between the hind legs to the chest and with careful movements they probe the abdominal cavity in the direction from the last ribs to the pelvic part. We must try not to damage the embryos or cause an abortion.
When determining pregnancy already at 45-50 days, mobile rounded dense formations (embryos) measuring 1.5-2 cm, located in a chain along the spine, can be easily felt. Experienced nutriologists can detect pregnancy even at 35 days.
When probing, adult females are calm, young- restless, which makes it difficult to determine pregnancy. Skillful, careful palpation and examination do not harm the female even in the last month of pregnancy.
In young females at 2-2.5 months, pregnancy can be determined by the size of the nipples, which by this time increase and differ in size from the nipples of single females. The approximate size of the nipples is given in table 11.
In females that whelp 2.3 times, it is not easy to determine pregnancy with this method, since after lactation the nipples do not decrease to their original state and remain enlarged, but not full (flaccid).
In addition, in nutrias during the first pregnancy, on days 28-30 after mating, exudate is released from the genital organs: on the first day there is a fairly liquid consistency with a slight reddish tint, in subsequent days it is viscous, red in color, then with blood clots. The volume of discharge varies from female to female.
Nutria pregnancy. Clear signs of pregnancy are noticeable a month and a half before giving birth, and by the end of pregnancy, some females become so fat that they take on a spherical shape. In a calmly sitting female, you can observe the movement of the embryos.
Long gestation period (127-132 days) compensated by the fact that the young are born fully developed, covered with hair, with open eyes and very mobile.
Cages containing pregnant nutria must be cleaned regularly. They should be comfortable, without holes in the walls of the house, partitions, or walks. It is impossible to delay the disembarkation of pregnant females from the pens, as this is fraught with abortions and miscarriages, in addition, pregnant nutria become aggressive and interfere with the mating of other females.
Handling pregnant nutria during feeding and cleaning should be calm; it is not recommended to suddenly appear near cages with pregnant females and make sudden movements; geese, dogs and other domestic animals should not be allowed near the cages. A pregnant female should not be held upside down by the tail for a long time.
It should be taken into account that some females do not make a nest before whelping and scatter the bedding, which can lead to hypothermia and death of the puppies, so there should always be dry bedding in the house.
Pregnant nutria should be fed according to established standards. In warm weather, they must be provided with drinking water, and in winter - with succulent food and clean ice (snow). Among succulent feeds, it is necessary to limit the supply of beets, as they have a laxative effect, which causes frequent straining, which can cause abortion.
If all conditions of feeding, maintenance and care are met, pregnancy in nutria proceeds normally. But there are cases when an obviously pregnant female remains without offspring. According to experts, not a single species of caged fur-bearing animals is as susceptible to abortion and embryo resorption as nutria. The reason for this is the lack of protein, succulent, vitamin feed in winter and spring, and excessive fatness of females. Traumatic abortions are very common.
Whelping. Most often, whelping occurs at night; birth in nutrias is almost always easy. Considered normal whelping duration from 20 minutes to 1-2 hours depending on the number of puppies in the litter, which come out every 20-25 minutes.
Nutria should not be disturbed during whelping.. The day before and after birth, the female does not touch the food.
The female eats the afterbirth licks wet newborn puppies. Having dried, the babies find their mother’s nipples and can sit next to her for hours without taking their eyes off the nipples.
In a whelping female, milk does not appear immediately, but several hours after birth. Nutria milk is high in calories and has good nutritional value.
By the end of the day after giving birth, the female’s behavior can be very restless; she leaves the puppies and runs around the cage excitedly. These are signs that the female is in heat and should be placed with the male for a short time.
Females who have given birth as a rule, they become aggressive, often rushing at a person, but by 2 months of lactation they gradually calm down.
After whelping, dirty, wet bedding should be removed. from the house and add dry fresh food, preferably hay. The afterbirth (if the female has not eaten it) and dead puppies are also removed.
A whelping female can be recognized by her appearance - her stomach decreases, her sides fall off, and sometimes sucked nipples are visible.
In some farms, females have a heated room for whelping on frosty days, where they are kept from 3 to 10-15 days to ensure the safety of the puppies.
Nutria gives birth to up to 18 puppies, average fertility is 4-5 puppies. The fertility of females depends on several factors. First of all, on their age at the first mating. Young females that are small in weight often give birth to small litters with reduced viability.
It is necessary to pay attention to the degree of fatness females at the time of mating. Excessive fatness (obesity) can lead to their infertility. Some nutria breeders, in order to obtain good litters from young females, allow them to mate at the age of at least 8 months and weighing 4-4.5 kg. A larger number of puppies in the litter occurs in females who whelped in the 1st and 4th quarters, that is, mated in the 3rd quarter (July-August-September), when the feeding and climatic conditions are most favorable: plenty of succulent green food, warm summer months. Thus, the average litter size for females covered in July and whelping in November is 5 eggs; females, covered in August and whelping in December, have 6 insides.
Reproduction of nutria at home is a rather labor-intensive process. If you do everything wisely, without making mistakes when choosing partners, you can get healthy offspring and profit from slaughter up to 2 times a year. From this article you will learn: when it is necessary to allow a female to meet a male, how nutria mating occurs, how to determine the pregnancy of nutria, why pregnant individuals need special care, how nutria give birth at home, why animals eat their young and much more.
Reproduction methods
In nutria farming, year-round and seasonal propagation of nutria is used.
In the first case, nutria mate all year round; the breeder keeps a special mating calendar with the names of the animals and lambing dates. The continuous breeding method allows you to get more offspring. But young animals obtained in the second half of the year have to be kept for more than a year, while the skins become marketable by the age of nine months.
Seasonal mating of nutria at home is designed so that the puppies appear in the first half of the year, then their fur matures by winter, and unnecessary costs for food and maintenance are eliminated. To meet these deadlines, females are placed with males in the first or second heat after lambing.
Selection of pairs for reproduction
For nutria to mate, different-sex individuals are required. To distinguish a female from a male, you need to examine the genitals of the animal. The female's genital slit is located near the anus, and the male's genital organ is several centimeters away from it. When palpating the lower part of the abdominal cavity, the testes of a male individual can be detected.
The selection of pairs occurs in order to obtain young animals that have the best qualities of their parents. Experienced nutria experts adhere to a number of rules when selecting a pair:
- It is not recommended to crossbreed related animals, as this can lead to degeneration of the species.
- The qualities that need to be improved are taken into account - fur quality, color, length, density.
- The best unrelated female, or a female specimen inferior to him in quality, is placed with the best male.
- There are homogeneous and heterogeneous selection of pairs, in which animals with similar characteristics are mated, and heterogeneous, when the male is better than the female.
- For replanting, individuals that lead in growth and development are preferable. Their offspring mature faster and have larger skins.
Definition of hunting
The period of hunting in female nutria can be determined by behavior and external signs. If the animal has become more active, eats less, urinates often, runs around the cage, paddles with its paws and lifts its tail, then the animal has begun to come into heat.
External signs of estrus are not clearly expressed. In some cases, it is determined by the genitals - redness and swelling.
The most reliable way to determine the onset of sexual heat is to place the female with the male.
The “playing” female will flirt with the male, follow him and sniff him. If the heat has not started, then the “bride” will reject the “gentleman”, scream loudly, try to hide, or try to fight with the “suitor”.
The female's hunting period lasts 2-3 days.
Types of mating
During mating, the female rises on her hind legs, moves her tail to the side and allows the male to approach her. It covers the female from behind. On average, nutria mating lasts one and a half minutes.
Mating occurs several times (no more than 7-8) with breaks, during which the rodents begin to massage their heads and other parts of the body.
Corral method
There are several ways to breed rodents at home. The simplest of them is penned or free breeding of nutria. With this breeding, animals live in pens of several individuals of both sexes. There should not be more than 12 females for 1 male. Mating occurs naturally, and pregnant females shed their eggs gradually. The disadvantages of the free method are the inability to improve the quality of the offspring and frequent squabbles between animals.
The jamb method
With the shoal mating method, separate groups are formed and placed in a separate room. Young females (no more than 14 individuals) are recruited into the school, selected by size and character in such a way that it is easier for them to get along together. Upon reaching six months of age, an older male is placed with them for the first mating. After a couple of months, pregnant individuals are placed in autonomous cages, the male and unfertilized females are kept with the main herd, and the next group of young nutria is moved into the pen.
Females after lambing, not fertilized until the end of lactation, are also distributed into schools.
Replanting method
The replanting method of mating is suitable for already mated nutria. The day after giving birth, the female begins the period of sexual heat; she is periodically placed in a cage with a male for a week. The procedure is repeated 2 more times: within a week, starting 24 days after lambing; from 50 to 62 days after it.
For the fastest results, mating is organized in the evening - the period of greatest activity of nutria. After intercourse, the female can be left with the male for a couple of hours.
Family method and pair breeding
The family method is a variation of the joint method. The difference is that the nutria family consists of female individuals from one litter (usually no more than 4).
Pair breeding of nutria is not a common occurrence, since it is the most ineffective. The male is kept with one female, so there are too many males to provide.
Pregnancy and childbirth
Definition of pregnancy
Many nutria experts with experience can determine pregnancy in nutria by the appearance of the nipples, attitude towards the opposite sex or appearance - in the last months of gestation, nutria gain a lot of weight.
A more reliable way to determine is palpation in the lower abdomen. The breeder's actions must be careful not to cause abortion. If you have no experience in palpating, then you should not touch the pregnant nutria before the 45-day period, until the embryos have hardened.
The first pregnancy of nutria can be determined by observing the female - young individuals secrete exudate (liquid with blood clots). This occurs approximately a month after mating.
Determination of gestational age
In the final stages, pregnancy is easy to determine - the expectant mother’s belly enlarges, and it becomes noticeable how the fetuses move.
Progress of pregnancy
The female carries offspring in her stomach for up to 130 days. Long gestation is compensated by the fact that the puppies are born fully developed. A pregnant female needs to be separated from other animals and given proper care - create peace, keep her clean and dry. Also, mother and unborn child need a special menu. It is imperative to make sure that the nutria eats enough and that the food provided is sufficiently enriched with nutrients. Lack of protein, vitamins and succulent food can lead to embryo resorption. Cohabitation of a pregnant nutria with relatives increases the risk of traumatic abortion.
The day before birth and during the next day after it, nutria does not eat.
Okot
During childbirth, nutria should not be disturbed. Lambing occurs at night and lasts from 20 minutes to 12 hours. The duration depends on the number of puppies.
Having lambed, the female eats the afterbirth and licks her offspring (up to 18 children). Puppies are born sighted and with hair.
Nutria may also eat its baby if:
- the birth was difficult;
- babies were stillborn;
- the animal lacks vitamins.
