To create environmental conditions for growing and finishing pigs

Intensive production is carried out in a high-density house feeding environment, and the microclimate in the pig house is the main environmental condition. The microclimate of pig house includes temperature, humidity, wind speed, gas, sound and so on. These environmental factors will directly affect the weight gain rate, feed utilization rate and final economic benefits of pigs.

1. Suitable temperature and humidity the ability of pigs to regulate body temperature is poor, only a few sweat glands can be regulated in hot days, and only very few hairs can resist the cold in winter. Therefore, the pig house must have a good effect of thermal insulation and be controlled by ventilation system. High production performance can only be achieved if the temperature and humidity are kept in an appropriate range to make the pig feel comfortable. On the contrary, either high or low will cause stress reaction in pigs and lead to adverse consequences. In addition, Jiangtao in China has a great difference in climate between the north and the south, so it is very important for pig production to create the most suitable temperature and humidity conditions for pigs.

The experimental study shows that the best temperature for producing good finishing pigs is 20 ℃. When the temperature drops, pigs are forced to eat more, and most of the energy consumed will be used to produce heat rather than meat. If the temperature is too high, the feed intake of pigs decreases. As the saying goes, "little pigs are afraid of cold, big pigs are afraid of heat", which shows that pigs of different weight require different temperatures. Studies have shown that the optimum temperature for pigs with 11-45kg live weight is 21 ℃, while that for 45-100kg pigs is 18 ℃, and that for 135kg-160kg pigs is 16 ℃.

When the ambient temperature is higher than 30 ℃, cooling measures should be taken, the longitudinal exhaust system should be turned on, cold water should be sprayed or green succulent feed should be fed. When the temperature in the house is too low, heat preservation measures should be taken to improve weight gain, and in the cold season in the north, doors and windows should be sealed to reduce the invasion of cold wind, some bedding grass should be added appropriately, and the addition of plastic greenhouse in open pig house can keep the meat pig house between 11-18 ℃ without affecting the weight gain of pigs.

The effect of temperature in the house on growing and finishing pigs is related to humidity, and the optimum temperature for obtaining the highest daily weight gain is 20 ℃ and the relative humidity is 50%. Under the most suitable temperature condition, the temperature had little effect on weight gain and feed utilization rate. The humidity level is related to other environmental factors, and may cause disease and indirectly affect the rate of weight gain.

2. The ventilation in the pigsty is directly related to the wind speed and ventilation volume. The ventilation speed has a certain effect on the daily gain and feed conversion rate of pigs. Some people used pigs weighing more than 40kg to compare the effects of different wind speed on production performance at different temperatures. When the temperature exceeded 37.8℃, the wind speed was accelerated, the daily gain decreased, and feed consumption was increased. When the temperature is 4 ℃-19 ℃, being attacked by thieves will also reduce daily gain and increase feed consumption.

Intensive and high-density growing and finishing pigs need ventilation all the year round, but the contradiction between ventilation and heat preservation must be solved in each season. We should not only pay attention to heat preservation but ignore ventilation, which will worsen the air hygiene condition in the house. reduce the weight gain of pigs and increase feed consumption. If you open the fan or south window at noon in North China and close the fan or window at 3-4 pm, you can reduce the humidity in the house and increase the fresh air. The closed pig house should maintain a temperature of 15-20 ℃ and a relative humidity of 50%. The air velocity should be 0.2m per second in winter, spring and autumn, and 1.0m in summer. The hourly air exchange rate of each pig is 45 cubic meters in winter, 55 cubic meters in spring and autumn, and 120cubic meters in summer.

3. Reasonable feeding density will significantly affect the production performance of pigs. It is generally believed that every 10 kilograms of body weight should have at least 0.1 square meters of ground area. The captive area (partially leaky floor) of each pig at different growth stages is 0.25 square meters for < 25 kg, 0.50 square meters for 25-50 kilograms, 0.70 square meters for 50-75 kilograms and 0.85 square meters for 75-100 kilograms.

4. The appropriate number of pig herds under the same captive area of each pig, the number of different pig herds will also affect the feeding effect. Some people compared the production performance of 8-16 pigs per ring with 16-32 pigs, and found that the former was obviously better than the latter. Under the condition of house feeding, the performance of the group was significantly improved, which was due to the reduction of tail biting and fighting.

The phenomenon of tail biting and fighting can be avoided by feeding in the original litter, and the social order of pigs in the original litter has been formed during the lactation period, which remains unchanged during the growth and fattening period, which is very beneficial to production. However, in the case of poor uniformity of pig breeds, it is inevitable that some weak pigs or low-weight pigs will appear. In this way, pigs with similar sources, body weight, physique, character and diet are raised in groups. The weight difference among individuals in the same group of pigs should not be too large, and the weight difference within the group should not exceed 2-3 kg in the early stage of piglets. After grouping, the stability of the group should be maintained, except that the physique is too weak to be adjusted in the group because of disease or excessive difference in weight, and should not be changed arbitrarily.

In addition, gregarious merging should also be carried out at night, and management and training should be strengthened to avoid or reduce the phenomenon of biting and fighting.