Prevention and Treatment Measures for Cage Layer Fatigue
Cage layer fatigue, also known as osteomalacia, is caused by insufficient or imbalanced vitamin D, calcium and phosphorus in layer feed. It is one of the most serious skeletal diseases in caged laying hens and often occurs during the peak laying period. Below, Qinnong Network will introduce this disease and the related prevention and control measures.
I. Symptoms
After the onset of cage layer fatigue, hens will become paralyzed, die and show a drop in egg production. The losses caused are manifold and can also affect the slaughtering and processing of chickens. At the beginning of the disease, soft-shelled eggs and thin-shelled eggs are laid, and the egg breakage rate increases, but there is no obvious change in appetite, spirit or feathers. Afterwards, difficulty standing, curved claws and unsteady movement appear. If detected in time and appropriate treatment measures are taken, most can recover within 3 to 5 days. Otherwise, the symptoms will gradually worsen, and eventually often cause lameness, inability to stand, a sunken breastbone, ribs that break easily and paralysis; necropsy may reveal brittle wing bones and leg bones.
II. Causes
As introduced above, the cause is insufficient nutrition or an imbalanced ratio in the feed. In fact, other causes can also lead to this disease. Qinnong Network has summarized the following points:
1. The calcium content in the diet of caged laying hens is seriously insufficient, and calcium and phosphorus are imbalanced.
2. Overly crushed stone powder and bone meal are absorbed quickly in the chicken's gastrointestinal tract and excreted quickly as well, reducing calcium utilization.
3. Low activity levels in caged laying hens can also cause cage layer fatigue.
4. During the rearing period, invasion by parasites and management-related factors can both cause this disease.
III. Preventive Measures
The prevention of cage layer fatigue is proposed according to the causes of the disease. In addition to ensuring balanced feed nutrition, a coarser calcium source can also be provided to laying hens. The specific preventive measures are as follows:
1. Ensure complete nutrition and scientific management so that growing chickens reach the best body weight and body condition when they reach sexual maturity.
2. Feed a special pre-lay feed containing 2% to 3% calcium 2 to 4 weeks before the start of laying, and when the laying rate reaches 1%, promptly switch to layer feed.
3. The calcium content in the feed of caged high-yielding laying hens should not be lower than 3.5%, and an appropriate calcium-to-phosphorus ratio should be ensured, with more than 2000 IU of vitamin D3 added per kilogram of feed.
4. Provide coarse granular stone powder or shell powder to laying hens. The coarse granular calcium source can account for 1/3 to 2/3 of total calcium. The calcium source particles should be larger than 0.75 mm, which can both improve calcium utilization and avoid graded precipitation of calcium in the feed. In hot seasons, spread coarse granular calcium evenly in the feed trough at about 1% of feed consumption every afternoon. This can not only provide sufficient calcium source, but also stimulate the appetite of the flock and increase feed intake.
5. Blood calcium monitoring should be done regularly. When soft-shelled eggs are found, blood calcium testing should be carried out.
IV. Treatment Measures
From the causes above, it can be seen that the causes of cage layer fatigue are varied, so the treatment methods are also different. When diseased chickens are found, promptly pick them out of the cages, place them on the ground and raise them separately, supplement bone granules or coarse granular calcium carbonate, and let the chickens eat freely. Diseased chickens can recover within one week. For diseased chickens that have stopped laying, if they are raised separately and ensured normal drinking water and feed intake, they will generally recover on their own within no more than one week. For chickens in the same flock with low blood calcium, add another 2% to 3% coarse granular calcium carbonate to the feed and add 2000 IU of vitamin D3 per kilogram of feed. After 2 to 3 weeks, the blood calcium of the flock can rise to a normal level, and the incidence rate will decrease significantly. The supplementation of coarse granular calcium carbonate and vitamin D3 needs to continue for about one month. If the disease is detected relatively late, recovery generally takes about 20 days, and individual severely affected paralyzed chickens may die.
The above is Qinnong Network's related introduction to cage layer fatigue, including symptoms, causes, prevention and corresponding treatment measures, hoping to provide some reference for laying hen farmers.