鸡舍通风系统设计与改造实践

Farm site selection is fundamental to successful poultry farming. The site should be elevated, dry, and well-drained with groundwater level below 2 meters. It must be at least 500m from residential areas, 1000m from major roads, and 3000m from other farms and slaughterhouses. Water sources must be abundant and meet national drinking water standards, with reliable electricity supply.

Chicken house construction should follow all-in-all-out principles. Environmentally controlled houses use negative pressure longitudinal ventilation, cooling pads, and automatic lighting systems to effectively control the microclimate. Floor density for broilers is 8-12 birds/m2, slatted floor 12-16/m2, and cages 20-30/m2. Layer cages provide approximately 400-500 cm2 per bird.

Duck house design must consider the aquatic nature of waterfowl. Ideal sites should be near natural water bodies or equipped with artificial ponds. Floors should have a 1%-2% slope for drainage with dry, loose litter. Goose housing can be simpler, though brooding houses need good insulation. Exercise yards should be 2-3 times the indoor area with shade shelters for hot seasons.

As environmental regulations tighten, treatment and resource utilization of livestock waste has become critical. Poultry manure contains rich organic matter and NPK nutrients. Each layer produces 40-50 kg of fresh manure annually. After composting treatment, a 10,000-bird layer farm can produce 200-250 tons of organic fertilizer worth approximately 100,000-150,000 yuan.

Ducks have higher crude fiber utilization than chickens. Meat ducks in finishing phase require 16%-18% crude protein with 2900-3000 kcal/kg ME. Beijing ducks reach 3.2-3.5 kg at 42 days with FCR of 1.9-2.2:1. Geese primarily consume green roughage, with adults consuming 1.5-2.5 kg of grass daily and achieving 45%-50% crude fiber digestibility.

Goose farming profitability varies by model and breed. Commercial geese take 70-90 days reaching 4-6 kg, with 3-4 batches possible annually in southern regions. Production cost is 45-55 yuan per bird including 10-15 yuan for goslings and 25-30 yuan for feed. Common white geese sell at 16-20 yuan/kg while premium breeds like Shitou reach 25-30 yuan/kg.

Incubation technology is crucial in the poultry industry chain. Modern farms universally adopt artificial incubation. Chicken incubation takes 21 days, ducks 28 days, and geese 30-31 days. For chickens: days 1-18 at 37.8C with 55%-60% humidity; days 19-21 after transfer at 37.2C with 70%-75% humidity. Duck and goose incubation requires slightly higher early temperatures and higher late-stage humidity.

Chicken breeds are categorized as egg-type, meat-type, and dual-purpose. Leading egg-type breeds include Hy-Line Brown and Lohmann Brown, producing 310-320 eggs at 72 weeks with FCR around 2.1:1. White-feathered fast-growing broilers like AA+, Cobb, and Ross 308 reach 2.5-2.8 kg at 42 days. High-quality yellow-feathered breeds such as Sanhuang, Qingyuan, and Wenchang chickens are prized for excellent meat quality.

Disease prevention is the top priority in poultry farming. Common diseases fall into four categories: viral, bacterial, parasitic, and nutritional-metabolic. Viral diseases include avian influenza, Newcastle disease, infectious bursal disease, and Marek disease, most characterized by rapid transmission and high mortality. Bacterial diseases include pullorum, colibacillosis, infectious coryza, and chronic respiratory disease.