How to prevent and treat cage layer fatigue? Soft-shelled and thin-shelled eggs, difficulty standing, fragile bones

    Cage layer fatigue, also called cage layer osteoporosis, often occurs during the peak laying period. If detected in time and appropriate measures are taken, most hens recover within 3-5 days. If detected late, recovery generally takes about 20 days, and a few severely affected paralyzed laying hens may die, causing losses.

Cage laying hens

    1. Symptoms: In the early stage, soft-shelled and thin-shelled eggs are laid, and the egg breakage rate increases, but the laying hens' appetite and feathers show no changes. Afterward, difficulty standing, curled claws and incoordination appear. In the late stage, the symptoms gradually worsen, and finally the laying hens become lame, unable to stand, paralyzed, with a sunken sternum, ribs that break easily, and wing and leg bones that are easily fractured.

    2. Causes: (1) Insufficient calcium content in the diet of caged laying hens, and an imbalance of calcium and phosphorus. (2) Overly pulverized limestone powder and bone meal are absorbed quickly and excreted quickly in the gastrointestinal tract of laying hens, resulting in low calcium utilization. (3) Caged laying hens have low activity levels and improper feeding and management. (4) Laying hens are invaded by parasites during the rearing period.

    3. Prevention: (1) Ensure complete nutrition and strengthen scientific management so that growing laying hens reach optimal body weight and body condition at sexual maturity. (2) Feed a special pre-lay diet containing 2-3% calcium 2-4 weeks before the start of laying, and when the laying rate reaches 1%, promptly switch to a laying hen diet. (3) The calcium content in the feed of high-yielding caged laying hens should be no less than 3.5%, with an appropriate calcium-to-phosphorus ratio, and add more than 3200 international units of vitamin D per kilogram of feed. (4) Provide laying hens with coarse-particle limestone powder or shell powder, with the coarse-particle calcium source accounting for 1/2-2/3 of total calcium. A calcium source particle size greater than 0.75 mm can both improve calcium utilization and avoid calcium stratification and sedimentation. In hot seasons, scatter coarse-particle calcium evenly into the feed trough each afternoon at about 1% of feed consumption, which can both provide a sufficient calcium source and stimulate the flock's appetite, increasing feed intake. (5) Blood calcium monitoring should be done routinely; when soft-shelled eggs are found, blood calcium testing should be carried out promptly.

    4. Treatment: When diseased hens are found, promptly remove them and raise them separately on the ground, and ensure the laying hens have normal access to drinking water and feed; generally they can recover on their own within no more than 1 week. For hens in the same flock with low blood calcium, add another 2-3% coarse-particle calcium carbonate to the feed and add 2000 international units of vitamin D3 per kilogram of feed. After 2-3 weeks, the flock's blood calcium rises to normal levels and the incidence decreases. Supplementation with coarse-particle calcium carbonate and vitamin D3 should continue for about 1 month.