The feeding and management of layers in high temperature environment

Entering midsummer, the majority of laying hens will face new challenges: the challenge is mainly due to persistent high-temperature weather, and persistent hot weather often causes chickens under intensive feeding conditions to be prone to heat stress and heat stroke problems. The main performances are: lower feed intake, lower egg production, thinner feces and lower body mass, and a large number of dead chickens, which cause great losses to farmers. In order to maintain high and stable production of chickens during high summer temperatures and avoid the occurrence of similar serious problems, it is recommended that farmers can adopt the following applicable feeding and management measures in combination with the local actual conditions.
First, try to improve the environment inside and outside the home to reduce the degree of heat stress The chicken farms in rural areas are generally simple in structure, surrounded by no shade plants, and there are no radiation protection facilities on the roof, and the birds are dense and crowded. , poor ventilation, chicken house temperature is often higher than the outdoor 3 °C ~ 4 °C. For chicks, the optimum temperature for growth is 10°C-22°C. For laying hens, 10°C-30°C is the best temperature range for egg production. If it is more than 30°C, it is suitable for growth. Food intake, egg production rate, egg size, and shell quality will all have an impact. In the hot season, the main measures to improve the internal and external environment are:
(1) Strengthen ventilation ventilation is an important measure to ensure the environment inside the house. In the continuous high-temperature environment, it is better to use vertical ventilation for closed chicken houses. The airflow in the vertical ventilation houses is evenly distributed, and there is basically no air flow dead angle. Fresh air can be fully utilized and the air speed is high. Above 0.5 m/s, it is good for heat dissipation of chicken body. For open chicken houses, when the temperature exceeds 27°C (especially in the afternoon), the method of relying on natural ventilation is powerless. Only when all the doors and windows of the chicken house are opened, it is best to let the lateral airflow pass through the house and cause ventilation effect. , Or install a fan in the house, use fans to increase the air flow in the house, remove the hot and humid air inside the house, so that the temperature within the house drops. Ventilate even at night to discharge heat accumulated during the day.
(2) Cooling with water Under conditions of high temperature and poor ventilation conditions, high pressure spray guns are sprayed on roofs at noon and afternoon each day to increase heat dissipation. Or use a sprayer to cool the fresh, cool deep well water or tap water with a chicken spray (or add appropriate amount of disinfectant to disinfect the chicken) so that the body remains moist and thus reduces body temperature.
(3) Ensure adequate drinking water In the summer, it is necessary to ensure free drinking water throughout the day, and to ensure fresh and cool, it is best to use deep well water and keep it flowing. If the water shortage is too long during the hot summer, it will inevitably affect the growth of chickens and the production performance.
In order to ensure that each chicken drinks enough fresh cold water, it is necessary to always check all the water tanks and nipple drinkers carefully, and confirm that there is no fault in the water supply device and there is enough water depth in the open water dispenser. In addition, people tend to neglect the drinking water space, and chickens often compete for drinking water. This indicates that the drinking water is not in sufficient position, which leads to insufficient drinking water in some chickens and is bound to exacerbate the heat stress reaction. It can be seen that it is very important to ensure that chickens can drink enough fresh and clean water at any time in the daily management.
Second, to strengthen nutrition management (1) adjust the diet for chickens from June to September into the peak period of egg production, as long as the daily intake of normal food to eat no less than 115 grams, generally can guarantee the average daily production of 50-55 eggs Grams / only (the ratio of eggs to 2.31). However, the hot environment often causes changes in the physiology and metabolism of laying hens, resulting in reduced feed intake and decreased production performance. Tests have shown that high temperatures lead to a decline in feed intake and that for every 1 degree Celsius increase in temperature, feed intake will drop by 2%. Therefore, for new hens weighing 1.9 to 2.1 kilograms, a decrease in intake means that the nutrient intake provided for the production of eggs is not sufficient and can be verified by the lighter weight of the eggs.
Therefore, in order to ensure the normal production of chickens, timely adjustment of the diet is appropriate to ensure the daily basic nutritional needs of the layer (eg 18 grams of crude protein, 275 kcal of energy, 360 milligrams of methionine, 720 milligrams of lysine , 3.5 grams of calcium, 0.4 grams of available phosphorus and essential vitamins, minerals, etc., so that it can compensate for the lack of nutrients caused by high temperature stress, meet the special needs of layer chickens, to some extent alleviate the harm of heat stress. The key nutritional control measures are:
1 Replace 1% corn with 1% fat. In a high-temperature environment, the demand for energy from the flock is low, and the feed intake of the flock is reduced accordingly. Therefore, the energy structure of the feed should be adjusted. In order to increase feed intake, some fat may be added to the feed. Fat can increase the palatability of the feed. In this way, feed intake can be greatly increased, and nutrient utilization can be increased, such as feeding 1% animal and plant fat instead of 1 %corn.
2 Lower protein levels. Since the demand for protein and amino acids in chickens is not related to the environment, the protein demand of chickens does not change during hot weather. However, when the environment rises to 30°C, the feed intake of chickens will decline. Protein levels should be increased, but at higher temperatures, heat stress directly affects the egg production rate, even if raising the same level of protein can not be improved, use low protein diet, while maintaining enough methionine (2% of crude protein), Lysine Acid (crude protein 5%) intake; excessive protein or amino acids, its oxidation heat, in addition, the correct amino acid level of diet can reduce the incidence of fatty liver, reduce mortality.
3 Properly increase the proportion of calcium and phosphorus. High temperature inhibits calcium intake and VD3 conversion. Therefore, in the high temperature environment, the calcium requirement of laying hens will increase. However, high calcium diets may reduce palatability, resulting in a decrease in feed intake. It is recommended that, as expected, Changes in feed intake increased the amount of premix admixed, maintaining a daily calcium intake of 3.5 grams and 0.4 grams of available phosphorus.
4 Apply other additives. When heat stress adds VC 150g/1000kg feed, the chicken needs a large amount of VC when heat-dissipating to increase the resistance to disease. When there is a problem of eggshell, consider adding sodium bicarbonate, and then test the diet. Sodium intake and the appropriate level of chlorine in the diet to improve the quality of the shell, adding 0.2% -0.3% in the feed is beneficial; the current application of 4% glucose water is generally appropriate, can relieve the heat stress on blood properties Influence, improve heat dissipation, and reduce the toxic metabolites in the blood; oligosaccharides are currently a class of green additives that are studied more and more, they can promote animal growth, enhance immunity, ensure animal health, oligosaccharides to improve heat The condition of poultry under stress has a certain role in the health status and production level. Adding 1% of musk, honeysuckle, Radix, Atractylodes, and gentian herbs in poultry feed can increase the egg production rate and increase the feed remuneration of laying hens during the high temperature season.
(2) Improve Feeding Methods Do not make any adjustments to the diet when there is sudden short-term (3-5 days) heat stress. Summer should choose a cool climate sooner or later, add more feed, add less at noon to ensure the intake of the diet, you can also use the method of less feeding Tim to enhance chicken excitement and strong appetite.