Influence of thermal stress on the reproductive performance of sow and prevention and control – Pig Disease Forum – China Animal Husbandry Website – A useful animal husbandry website
The concept of thermal stress is proposed in 1936 by Canadia, and the heat stress refers to an animal response to a high temperature environment.
Thermal should often make the pigs show the decrease in the feeding, less dynamic, mentally lost, increased drinking water, respiratory frequency disorders, decrease in immunity, and decrease in production performance.
To ensure that sow reproductive ability is one of the most powerful measures for the healthy development of pigs.
The reproductive performance of the sow is mainly affected by the two major factors of non-genetic and genetic factors. Nutrition, environmental and management belongs to non-genetic factors.
Environmental factors have instantaneous and variability, which can largely affect the reproductive performance of the mother pig. Pigs are constant temperature animals, the sweat gland is not developed, there is a thicker fat layer, the mother pig is large, the heat is hot, the heat is slow, when the heat stress exceeds the pig itself, its life can take different degrees of obstacles, mother The reproductive performance of pigs is seriously affected, and even the serious consequences of pig death.
The propagation performance of the sow is affected by thermal stress, which can destroy the body’s heat balance of pigs, reduce its ability to resist disease.
First, the effect of thermal stress on the sow
The sow is higher in the ambient temperature, higher than 23 ° C, the adverse reactions of thermal stress began to appear; higher than 27 At ° C, the reproductive properties of the sow are damaged to some extent. The effect of thermal stress on the sow is as follows.
1. Thermal stress causes constipation
The summer season, high temperature weather leads to the high temperature in the sow. When the temperature in the pig house lasts more than 32 ° C, it can cause the heat stress of the sow, leading to the temperature rise of the mother pig, the respiratory rate is accelerated, the electrolyte metabolism is disordered, and there is more moisture in the body. Constipation has occurred during metabolism disorders. The accumulated feces fermentation in the intestinal fermentation, causing the temperature rise of the body and systemic diseases.
At the same time, the toxins produced by the feces abnormal fermentation caused by blood to cause damage to the body organs, resulting in various inflammation such as uterine, breastitis.
In addition, the toxins produced by fecal fermentation and caused by milk caused piglets under the milk. The appetite of the sow in the event of constipation, malnutrition, decline in the quality of the milk, which in turn affects the development of piglets. Constipation will also cause a sow to be slight or irritated, it is easy to bite, dying,Clip to the pig.
When the constipation or constipation is serious, it can cause sows to rectal or even off the palace, leading to postpartum sows not normal estrus, even unsatisfactory, and the use of sows is shortened, which in turn reduces production efficiency.
2, the influence on the endocrine of sows
Thermostat is adjusted by nerve-body fluid, promotes the secretion of adrenalin and glucocorticoids, and improve the threshold of gonadotropin release hormones. The reduction in yellow body and macrodine, affecting the production, maturation and discharge process of the egg, reduces ovulation; inhibits the production of progesterone and yellow body, affecting the development and maturation of embryo, so that the number of dead fetuses and the number of mummy are raised.
In addition, the high temperature of the external environment can increase the temperature of the mother pigs, which is not conducive to the bed and development of the fertilized egg.
Sexy hormone is dominant in animal breeding, and an animal’s sex hormone secretion will seriously affect its early development conditions and later reproductive performance.
The effect of thermal stress on the secretion of sows is very obvious, and if appropriate, appropriate response measures are not taken, the reproductive performance of sows will be affected.
3, affecting the estrus time of the sow
Thermal stress can affect the secretion of maternal pig reproductive hormone, inhibit estrogen secretion, and delay the estrus of the sow. When the temperature is higher than 28 ° C, the breeding time of the sow can be postponed for 3 to 7 days. The first matching pigs can even postpone for about 20 days, which is consistent with the results of Zeng Xinfu, etc., that is, the hot stress can make the sow. Emotional delay after weaning.
The thermal stress extended the time interval of the sow to break the milk to estrus, increased the sow’s empty time, greatly reduced the “utilization efficiency” of the sow, directly increased the feeding cost, impact of sows. The economic benefits of the pig farm.
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4, the effect of the sow (
Light, the difference in temperature can vary by the sow to change with the season. Among them, the difference in environmental temperature is considered to be the most important factor, high temperature can lead to a sow return rate.More than 20% or even higher.
The sow is rising in the spring, winter, autumn, and summer, and the summer return rate is higher, and the summer return rate is higher than the other three seasons. High temperature weather can make the mother pigs are extremely significant (
The fetal rate directly affects the number of maternal pigs, the amount of child is low, the number of sows is reduced.
5, for the mother The influence of the number of pigs
The reciprocity of the fetch, the quality of the semen can affect the number of mother pigs. The egg production, maturation, discharge and transportation process are affected by thermal stress.
The study found that a pig group rose from the average number of averages in February, and after July, the average decline in each month in the second half of the year was generally lower than in the first half of the year, and the dying in the first half of August. The highest number of sows in the number of sows in the number of sows in Breeding in 7 to September is lower than the other months.
During the 6th to October, the number of sows produced and the number of sows in the production The number is low, and the study found that the ambient temperature can cause a number of large white pigs to fall by 0.020 head and 0.013, respectively. <0.01）地降低，且气温与受胎率呈负相关。
This can be seen that the heat stress The impact on the number of mother pigs is large.
6. Influence of embryonic mortality and childbirth
High temperature is easy to cause an increase in embryo mortality, so that the sow is returned Upward trend, the number of deaths in the sow is significantly rising and high temperature. High temperature can reduce the childbirth rate of sows, directly affect the number of mother pigs.
Second, thermal stress prevention and control Measures
1 Role. High temperature weather should take ventilation measures to reduce the temperature of the pig house, increase the heat dissipation of the pig. Wet curtain cooling system, spray system, with fan, has a good role in cooling the environment in pig house.
2) Supply adequate cleaning drinking water
In high temperature environments, the discharge of pigs in pigs is mainly breathing.Implementation of moisture in volatilization. Practice shows that cold water to drink 10 ~ 15 ° C for the heat should increase the amount of feeding, and the feed conversion is improved.
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2, in the thermal stress environment, change the pig, nutrition
1) In order to improve the feeding capacity, change the feed formulation
Small grease can give pigs to achieve higher net energy, and the pigs receive less body heating, so 4% to 5% oil can be added to the feed.
Improve the crude protein ratio of the feed to improve the feed utilization. Wet mixing can increase the amount of pigs in pigs to a certain extent, but must pay attention to feed quality.
2) Adding anti-thermal stress additives, improves sow immunity
Adding feed nutritional levels to help increase the immunity of pigs. Appropriate amount of vitamin C and vitamin E can improve the immunity of sows, enhance heat stress, and increase feeding capacity. A certain amount of salt can be added to the feed and drinking water to ensure the acid base balance in the sow. 3 Body heat, eliminate old, weak, sick, disabled pigs, reduce feeding density, reduce the temperature in the pig house.
The morning and evening temperature is relatively low, and it is good for feeding in the morning and evening, which is beneficial to the pig’s eating.
2) Adjustment to the breeding time and exercise time of the sow
3) Guarantee that there is a qualified sanitation environment
Keep the pig house cleaning to prevent the propagation of pathogenic microbial breeding, and can protect the sow from the endometrium to a certain extent. The infringement of inflammation, inhibits most high thermal diseases;
qualifiedThe health environment is also an effective protection for new studios.
4) Strengthening the prevention and control of the mother and pig disease
In response to the actual situation of the pig farm, immunization in accordance with the scientific immunoassay, preventing the occurrence of pig diseases. The vaccine should try to avoid the time period with high temperature, which can be carried out early, late, avoiding the impact of the thermal shouldage tract. Division of pig houses and overalls in accordance with period.
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Third, the small junction
In summary, the thermal stress brought by the summer high temperature can be more harmful to the reproductive performance of the sow. The endocrine disorder of breeding sows, delayed estrus, decrease in fetal rate, decrease in childbirth, increased embryo mortality;
Therefore, it is necessary to understand the heat stress to the sow, by increasing facilities Comprehensive measures such as strengthening management reach the preventive effect, promoting the health and efficient breeding of sows.
Qi Yuan Chen School: Yuan Yuan
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