Summer sow 热应 应 激 – 养猪 学 – – China Animal Husbandry Website – A useful animal husbandry website
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The loss of appetite in thermal stress is lowered, the endocrine state changes, resulting in weight loss of the sow to breastfeeding, feeding breastfeeding Reduce, piglet growth rate is lowered; and the heat should also delay the reproduction of the sow after weaning. Plenty of drinking water, reasonably feeding, changing nutrient ratio and dilute water cooling can effectively reduce the effects of thermal stress on sows.
Pigs management is the core of scale pig farm management, and pig farm benefits depends on the level of health and reproduction levels of sows. The skin of the sow is more affected by the heat stress affected by the summer. The continuous high temperature weather in summer has a great impact on the reproductive performance of the sow of the scale of the pig farm. The lactating mother pigs decrease in thermal stress, the endocrine state changes, resulting in the weight loss of the sow breastfeeding period, decreased by the breastfeeding, the growth rate of piglets is reduced; and the heat should also delay the reproduction of the sow. Plenty of drinking water, reasonably feeding, changing nutrient ratio and dilute water cooling can effectively reduce the effects of thermal stress on sows. The suitable ambient temperature in the breastfeeding sow is in the range of 15 ° C to 20 ° C, which is comfortable at suitable temperatures, the sow feels comfortable, more feeding, high feeding, rapid growth of piglets, high breeding rate, and lactation , Weaning to the shorter space, high in the fetus.
Every year from January to September, the temperature in most parts of my country is above 30 ° C, so the breastfeeding sow often suffers from summer heat stress. According to reports, the thermal stress will reduce the amount of fishing during lactation, and the loss of sows is increased. Decreased fever, the pig growth rate is reduced by 20% to 25%, and will delay the reproduction of the mother pig breast milk. In addition, the death of the mother pig and the death of piglets are also related to the high temperature environment.
1 summer heat should have a negative impact on breastfeeding sows
1. The feeding capacity of the mother pig
The maintenance of breastfeeding and breastfeeding is high, During breastfeeding is often unable to meet this need. According to foreign research reports, sows will reduce feeding volume in thermal indications, reduce metabolic fever (see Table 1). The reduction in the feeding capacity of the heat should be carried out by reducing the number of feeding daily, not by changing the amount of feeding or feeding speed.
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1.2 The sow is breastfeeding
The heat should reduce the production performance of the sow to a certain extent due to the decline in the feed. In fact, under the condition of hot conditions, the reduction in energy intake results in a reduction in fever, which is higher than the mammal decrease in temperature in temperature moderate conditions. It indicates that high temperature has a direct impact on the reduction in fever, which may be related to the body temperature regulation mechanism of pigs themselves. Under high temperature weather, sows are protracted by breathing and behavioral adjustment (drinking water or changing posture). The growth rate of summer piglets is generally lower than in winter, essentially caused by changes in ambient temperature. A number of studies have shown that it is reduced in a hot environment in a hot environment. In hot days, the beneficial effect of adding dairy on breastfeeding pigs is greater than the winter effect, thereby reducing the seasonal difference between the growth rate of the neck.
1.3 The child after the sow is broken
Thermal stress caused the latency of the sow after weaning, relative to the sows, this phenomenon in the head sow More more. The moisturized hot environment can delay the young sow at the early days of the young sow, when it is more than 28 ° C, the sow is more mature, born in the hottest month of the mother pig, the first age is delayed by 21D, the heat should be protected The little sow is only 20% in October. Karlberg reported that the time after the initial mother pigs were restored after 7 to September than the long and other months of other months, there were 46.2% of the ovaries in the initial production of the other month after weaned, there was yellow body (silent), and 38.5 % Qi (not estrus).
1. The endocrine of the sow
The lactation mother pigs will change their secretion. The sow is in a temperature environment of 30 degrees from the ninth day of lactation, compared to 22 degrees, the average level of oligin (LH) in serum is not affected, but the pulse frequency of LH at the 24th day is lowered ( Barb et al, 2001); sow heat should reduce reproduction rate, estrus delay after weaning, to a certain extent, due to the low temperature environmentHowever, it causes the LH pulse frequency reduction. Biensen et al. (1996) reported that the concentration of 17β-estradiol concentration in the sow in the sow was lower than the cool conditions under the hot conditions. The reduction in the concentration of 17β-estradiol is related to the interval time of weaning to re-estrus.
2 reducing the anti-stratification of breastfeeding
2.1 provides sufficient drinking water
Under normal circumstances, the water ratio of the feeding of the breastfeeding sauce is 1: 3, when the temperature can be Reached 1: 4 ~ 1: 5. The daily drinking water of a natenammal sow is generally 20L to 25L, and it has to reach 30L at a high temperature. If the sow in the summer, if there is no sufficient drinking water, it will inevitably suppress its feed. At the same time, pay attention to the following points: (1) The water dispenser is to be installed in the position of the sow is easily accessible; (2) must have a suitable water flow rate, the flow rate will make the sow, Resulting in a decline in feeding and breastfeeding. According to foreign research, lactating water flow speed is 2L / min in summer; (3) To know that the duck-type water dispenser does not ensure that each mother pig can get sufficient drinking water, it is necessary to supplement drinking water in the feeding. When there is no drinking, when water is supplied with the feed, it is necessary to replace drinking water, and ensure that the sow can drink cool drinking water at any time. When the pig is high, the water is more water, the cool water is more effective, and the cooling of the pig is more effective.
2.2 rationally arrange feeding
Increase the number of feeding, increased sow, it is generally not limited to 2 times ~ 3 times during the day, fed 1 time at night, or take Free feeding. Feeding volume can be increased in summer with cool water moisture or granule feed. A bracomid, 10 heads, 12-headed fever, and the feeding volume should reach 6kg to 7kg during the mammal.
2.3 Change Nutrition Comparison
The mother-induced pig appetite is not good, it is advisable to choose a good quality, fresh quality raw materials cooperate with diet. At the same time, high energy (DE13.4MJ / kg or more), high protein (more than 17%), highly lysine (0.85% ~ 0.90%), diet, add ω-3 unsaturated fatty acid content in diet Fat, can have useful effects on the feed of sows under high temperature environment. Appropriately reduce the ratio of high fiber raw materials, control the crude fiber level of the diet to reduce the generation of body heating. Increase the content of VE and VC in diet, moderate amountAdd (250 mg / kg) baking soda Nahco3.
2.4 Effective cooling in the house
Ventilation and evaporation are the main cooling measures of closed pig houses. Common cooling systems have a wet curtain – fan cooling system, spray, spray cooling system and drip cooling system. Spray, spray will increase the internal and bed humidity, generally used for roof cooling. The drip cooling system is most suitable for breastfeeding pigs in the column, the dripper is mounted above the sow’s neck, with a drop of water every 45min ~ 60min, the dripper regulates the shoulder to make the shoulder moist and will not drop. To the ground, the cooling effect is remarkable. It should be noted that the ideal catenary environment should provide different microenvironment in sows and piglets to make both of them in their respective humidity, and not to cause heat stratage of sows on the one hand. On the other hand But the piglet is cold.
2.4.1 Wet curtain – fan cooling system principle and parameters
Wet curtain – fan cooling system mainly uses water steam heat absorption to achieve cooling principle, the specific work process is: wet curtain installation North end face in the greenhouse, fan mounted in the south end of the greenhouse. When it is necessary to cool down, start the fan, force the air in the greenhouse to extract, resulting in negative pressure; at the same time, the water pump hits the water on the opposite wet curtain wall. When the outdoor air is negatively inhaled in the room, pass through the gap of the wet curtain at a certain rate, resulting in a moisture evaporation, cooling, cold air flow vapor flow, and after absorbing the indoor heat, the fan is discharged, thereby achieving cooling.
Main parameters: The selected wet curtain should have a large evaporation specific surface area and a lower overcurrent resistance loss to ensure that the wet curtain has high cooling efficiency, extending the service life. Table 2 is the main technical parameters of commonly used wet curtains. Wet curtain pad paper specification is: height 1000mm, 1500mm or 1800mm; width 600mm; thickness is 100mm ~ 150mm, non-standard specifications are determined by users with manufacturers.
Water pump necessary water supply: w = C × B × D + λ | E |. Where: W is the water supply amount of water pump, M2 / S; C is the amount of water supply for the top unit area of the wet curtain. According to the experiment statistics, C = 3.5-4.0m3 / (m2 × s), the wet curtain is higher than the high width; B is the total width of the wet curtain, and D is a wet curtain thickness, λ is necessary to discharge water and evaporationThe ratio of water volume, λ = 1.0 to 1.5, and the cation concentration of water is high or the pH is large.
The requirements for water temperature: Q = (3141-2.3t). Where: Q is the evaporation of water, KJ / Kg; T is the absolute temperature of the water. Obviously, when the evaporation is cooling, the low temperature water is good than the normal temperature water temperature, but does not significantly, from the economic point of view, it is generally used to evaporate and cool the temperature.
Water pump selection: The water pump is generally calculated from the formula 1.2W (m3 / s) × 3600 (m3 / h) calculated water supply. The water can be constructed when it is recycled when it is recycled. The minimum effective volume of the collecting pool is generally 30% to 40% of the total volume of wet curtains.
2.4.2 Spray, Spray System Cooling Principle
In most cases, outdoor temperature is uncontrollable, spray, spray system can locally control the temperature of the large environment . The spray cooling system is emitted to the water fine particles in the air, absorbing the heat in a large number of surroundings in the process of gasification, thereby reducing the temperature of the surrounding environment, is an effective means of heatstroke cooling. Each gram can cool the air by about 2 degrees per gram, for outdoor air, the efficiency of spray cooling is high, in theory, the energy required to spray cooling is the energy required to overcome the surface tension of water, When the water of 1 cubic meter turns 10 micron cubes, the energy required by the surface tension is about 43,200 Joules, while the evaporation of the latent heat is 2.2 billion Joules, and its theoretical energy efficiency is up to 50,000. The spray cooling system is emitted to the water fine particles in the air, absorbing the heat in a large number of surroundings in the process of gasification, thereby reducing the temperature of the surrounding environment, is an effective means of heatstroke cooling.
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2.4.3 Drops of the water temperature reduction system
Suitable temperature regions of sows are 15 ° C ~ 20 ° C, preferably no more than 26 ° C, while piglets are It is comfortable when 30 ° C ~ 32 ° C, in order to solve this contradiction, usually use different environments to sows and piglets, often used in summerDrip cooling method, on the one hand, it helps to maintain a suitable sow cool environment (the surrounding wind speed is not less than 0.6m / s ~ 1.0m / s), and it can also maintain a higher temperature in piglets.
Tenra and positive pressure airway mounting height from 1.2m, flat position in the head end of the pig, 0.3m from the column, drip drip with a 2L / h speed drip to the sow’s head neck, At the same time, the positive pressure duct will send the wind to around the pig. When the temperature in the house was 32.5 ° C, the sow body temperature was 39.9 ° C ~ 40.2 ° C, after the drip cooling system was operated, the sow body temperature decreased by 0.5 ° C, the average wind speed of the sow was 0.6 m / s ~ 0.8 m / s. Regarding the choice of local ventilation, there is no corresponding reference and data in China, and the recommended air volume of local non-cooling air for childbirth mother pigs is 119m3 / (h. Head).
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