蛋鸡热应激的生理反应与营养调控

Scientific diet formulation is key to controlling farming costs. Chicks (0-6 weeks) require crude protein at 20%-22% and metabolizable energy of 2800-2900 kcal/kg. Growing chickens (7-20 weeks) need protein reduced to 16%-18% with increased crude fiber. Laying hens require 16%-17% crude protein, 3.5%-4.0% calcium, and 0.5%-0.6% phosphorus, with a Ca:P ratio of 5:1 to 6:1.

Energy and protein are the two most critical nutrients in poultry feed. Corn serves as the primary energy source at 55%-65% of the diet. Protein supplements include soybean meal (15%-25%), cottonseed meal, and rapeseed meal as plant sources, plus fishmeal and meat-bone meal as animal sources. Mineral supplements (3%-5%) and premixes (0.5%-1%) are also essential.

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.

Phase feeding is recommended in practice: high-energy high-protein pellets for brooding, reduced-nutrient mash for growing, and dynamic adjustment based on laying rate for production periods. Precision nutrition can improve feed conversion by 5%-8%. Regular testing for mycotoxin levels is essential, and moldy feed must be strictly discarded.

Nutritional regulation during peak laying is critical. Hens producing above 90% need daily intake of 18-20g crude protein, 4.0-4.5g calcium, and 350-380mg available phosphorus. Supplementation with 0.1%-0.2% methionine and 0.05%-0.1% lysine significantly improves egg weight and production. Vitamins C and E play important roles in stress resistance.

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.

Candling inspections during incubation include first candling (days 5-7), second candling (days 11-14), and third candling before transfer. First candling checks fertilization and early development, second checks development progress, and third removes dead embryos. After transfer, turning stops and quiet conditions are maintained. Chicks remain in the hatcher until feathers dry, followed by sexing, vaccination, and beak trimming.

Geese are classified as large, medium, and small types. Large breeds like Shitou goose reach 10-12 kg for adult males. Medium breeds like Wanxi White, Zhedong White, and Sichuan White weigh 5-7 kg and produce 30-50 eggs annually. Small breeds like Taihu, Huoyan, and Wulong geese have superior reproductive performance at 60-100 eggs per year, serving as important genetic resources.

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.

Vaccination is the core measure for preventing infectious diseases. Standard layer immunization: Marek vaccine at day 1, ND-IB bivalent at day 7, IBD at day 14, ND booster at day 21, AI vaccine at day 35, and EDS vaccine before laying. All vaccinations must follow proper procedures, and vaccines must be used within 2 hours of dilution.

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.