by Estrus in pigs (the desire to walk) is the period of ovulation, during which the animal must be mated with a boar or artificially inseminated to obtain offspring.
Occurs every three weeks and lasts up to three days. Some animals may even go into heat during pregnancy, which allows them to be fertilized again.
In this article, we will look at how often pigs go into heat, how to recognize its onset, how long this period lasts, and how to synchronize this process in different pigs in a herd.
When does the first hunt begin?
The first heat can occur in a pig at the age of 5 months. However, during this period, it is not worth mating her with individuals of her own or another breed, since many animals during this period do not yet have sufficient body weight to successfully bear offspring.
You can plan the first mating if the animal has already reached the age of 10-12 months.
The animal selected for insemination must fully correspond to the parameters of its breed, and not have any visible defects or pronounced diseases.
To ensure that the pig is completely healthy, it can be shown to a veterinarian before mating.
Frequency of the walk
In females that have reached sexual maturity, hunting occurs regularly at intervals of 18-24 days. If insemination does not occur during the next hunt, the pigs can be mated again after 21 days.
The only exceptions are those cases where the sow is underweight to bear and give birth to offspring, her heat may occur irregularly, and in such a case, mating her is not recommended.
Some sows may go into heat even during pregnancy. In this case, the pig can be placed on a boar again. After this, two farrowings in a row can be expected with short intervals.
What does the sexual maturity of a pig depend on?
It is impossible to say exactly when puberty occurs and after what time a pig starts walking. Everything depends on the specific breed, the availability of a spacious, warm pigsty and the conditions of keeping.
Females become sexually mature at approximately 4-6 months.
Diet is of great importance. Maturation is delayed if the pig eats little or does not receive enough vitamins and protein. But excess nutrition also delays the process. In obese pigs, sexual maturity occurs later, and reproductive potential is reduced.
Puberty is delayed by constant stress, cold or extreme heat, life in a dirty or overcrowded pen. And also by conditions that cause physical discomfort: lameness, broken limbs, cracked hooves, dermatological diseases.
The process is slowed down if inbreeding is practiced on the farm – mating pigs of the same breed. Interbreed crossing accelerates the sexual maturation of the offspring.
Also, communication between pigs and the opposite sex before mating begins has a positive effect.
How do you know if a pig is in heat?
You can tell that a pig is in heat by several signs, including:
- swelling of the genital loop, as well as nipples;
- frequent urination;
- the appearance of abundant mucous discharge from the genitals;
- refusal to eat food not caused by gastrointestinal diseases;
- increased anxiety, aggressive behavior, throwing the water bottle and feeder in the pen.
To determine for sure whether a sow is in heat or not, you can approach her and lightly press her backside with your hand. If the pig shows anxiety and tries to move away from the person, it means that the time for hunting has not yet come.
If the female stands still and resists when you try to move her forward, then you can already put her to the boar, she is already ready for mating.
How long does farrowing last?
After the first signs of hunting appear, pigs enter estrus, which usually lasts 2-3 days. During this period, artificial insemination or mating of the pig with a boar is necessary.
If the insemination was successful, the hunt will not be repeated in the next month. The gestation period lasts 114-117 days. If, 3 weeks after mating, the sow shows signs of hunt again, she must be inseminated again.
How to identify a sow?
It should be noted that not all female pigs are suitable for giving birth to piglets. Before artificial insemination of a pig, it is necessary to conduct all necessary veterinary examinations.
If a pig has not become pregnant after 3-4 inseminations, it must be shown to a veterinarian. If he confirms that the individual cannot produce offspring, it is sent for slaughter.
Artificial insemination helps reduce the risk of spreading infectious diseases.
How to regulate the time of the binge? Synchronization methods
In order to rhythmically and systematically manage reproduction processes in pig breeding practice, they resort to the use of various hormonal drugs and their analogues.
This allows for intensive and rational use of breeding stock and the provision in advance of the necessary production operations and the timing of their implementation.
Synchronization of heat allows the formation of specific groups of sows of the same production phase, which means that the preparation of premises, artificial insemination and the corresponding movement of animals can be carried out in a short time.
In pigs, synchronization of heat can be achieved using various methods.
The following are considered the most effective:
- After weaning of their piglets, sows are given Follimag at a concentration of 500-600 IU in 2-3 ml of saline solution per animal. The drug is administered intramuscularly. When the animal goes into heat, 5 mcg of Surfagon is administered one hour before mating. The method can be used both during mating with a boar and before artificial insemination.
- Introduction of Follimag and Suffragon only to those females that have not entered heat within 14 days after weaning. This method can be used if the majority of the herd entered heat within the normal time after weaning.
The presented methods of synchronizing estrus in pigs can be used only after prior consultation with a veterinarian.
It is not recommended to undertake such measures on your own, as in some cases they may have a negative impact on the condition of the livestock.
The mechanism of action of these drugs on the body of pigs is that suisynchron blocks the secretion of pituitary gonadotropins, and therefore causes inhibition of follicle growth, the ovulation process and external signs of estrus.
After the effect of suisynchron ceases, the entire group of pigs simultaneously begins to go into heat, which is stimulated by the additional introduction of SFA.
Stages of the sexual cycle
Understanding the specifics of the sexual cycle is as important as knowing when a pig is in heat.
It includes four stages:
- First, the stage of arousal begins – proestrus. It is this that reflects the main feature of the heat – a change in behavior. Even the calmest sow becomes aggressive and nervous. Proestrus lasts 4-5 days. In pigs that have given birth, the stage of excitement passes faster.
- At the peak of estrus, sows begin to hunt – the estrus stage. At this stage, mating of animals takes place.
- Then comes the stage of calming down (metestrus), when the genitals turn pale and decrease in size. There is practically no discharge.
- The last stage is rest (diestrus). It begins approximately on the 6th-7th day of the sexual cycle and lasts about 2 weeks. The pigs’ behavior normalizes. They behave calmly.
What to do if the hunt does not start?
There are several reasons why a pig may not go into heat.
Among them:
- too many animals in one room;
- absence of a young boar in the pen (there should be one) or the number of heads in the barn does not correspond;
- improper nutrition of the pig, due to which its body may lack the necessary vitamins and microelements;
- diseases of the genitourinary system.
If the boar cannot cover
If the breeder notices that a sexually mature animal is not in heat, the female must first be taken to the veterinarian.
If the doctor discovers certain diseases in the animal, it must be treated.
If no diseases are detected during the examination, it is recommended to introduce young boars into the barn with the females – this stimulates the onset of estrus in the pigs, as does the method of inducing it with Oxytocin.
It is also necessary to ensure that animals are regularly walked in the fresh air, since excessive weight gain can also affect their sexual activity.
Mastitis in sows is one of the common reasons for the absence or lack of expression of signs of heat.
To stimulate hunting, you can also use special stimulants prepared on the basis of the urine of a mature boar. They must be sprayed in the stall where the female who is not in heat lives. This method is considered the most effective.
How to stop a pig from going into heat?
If the breeder does not plan to mate the pig when it comes into heat, folk methods can be used to bring down this condition.
Among those:
- Placing a copper plate on the bottom of a wooden trough with water. Allows to reduce the female’s attraction and calm her down.
- Adding Suinsichron to feed. It should be used within 18-20 days. The drug should be added to food when the first signs of hunting appear.
- Adding mash to pig feed. In this case, the animal will sleep more. This method should be used until the end of the hunting period.
The presented methods are safe for pigs, they only have a temporary effect on the female’s body. In order to successfully mate during the next hunt, the breeder only needs to eliminate the influence of these factors on the animal’s body.
It is not recommended to use (inject) heat suppressants for pregnant pigs. In this case, the breeder should simply wait 2-3 days until it goes away on its own.
Conclusions
- Pig heat can begin (come) as early as 5 months of age. However, for mating it is necessary to take animals aged 10 months or more, corresponding to the species characteristics.
- It occurs every three weeks. It lasts (periodicity) on average 2-3 days.
- Define (to distinguish, to recognize) the beginning of hunting can be by the swelling of the pig’s nipples and genital loop, the appearance of abundant mucous discharge, the restlessness of the pig, as well as the animal’s refusal of its usual food.
- Synchronization can be carried out by administering Follimag and Suffragon to animals.
- If the animal has not started hunting, it is recommended to introduce young boars into the pigsty (to cover the pig), improve the feeding of the animals, and also to use excitatory sprays. The latter are most effective if artificial insemination of the pig is planned.
- To suppress the desire to go for a walk in an animal, it is possible by adding mash or special preparations to the feed. This can be done only on the recommendation of a veterinarian, so as not to harm the animal.
