Methionine is an essential amino acid commonly included in the feed of laying hens. It plays a crucial role in promoting growth, enhancing egg production, improving feed conversion efficiency, and ultimately increasing economic returns for poultry farmers. However, excessive supplementation of methionine can lead to metabolic imbalances in the hens, causing serious health issues. A real case of methionine toxicity in laying hens is presented below.
**1. Incidence:**
A farmer raised 1,100 layers that were initially growing normally and had started laying eggs while being fed a complete feed. To accelerate egg production and recover investment quickly, he decided to add extra methionine to the feed. After two weeks, the hens began drinking more water but showed no improvement in egg production. Ten days later, some chickens started eating less, drinking more, and their egg production dropped. They began producing small, thin-shelled, soft eggs, along with feather loss, lethargy, oral discharge, and apathy. Despite medication, the condition worsened, and several birds died.
**2. Pathological Findings:**
Upon necropsy, the affected hens showed similar pathological changes. The liver was enlarged, fragile, and yellowish; the kidneys were swollen and brittle. The intestines were thin, and there was fat accumulation in the heart. A small amount of pus was found in the cloaca, and the ovaries and oviducts showed mild inflammation.
**3. Diagnosis and Treatment:**
Based on clinical symptoms, dietary changes, and post-mortem findings, the condition was diagnosed as methionine poisoning. The original feed was immediately discontinued, and the hens were provided with clean water supplemented with 5% glucose and 0.01% vitamin C. Fresh, green vegetables such as cabbage and kale were chopped and offered daily. Additionally, they were fed a homemade feed mixture containing 2% complex enzyme, 2% licorice powder, and 3% mung bean flour. After ten days, the sick hens gradually recovered, and symptoms disappeared. Within 30 days, egg production returned to normal, and after 37 days, egg production reached its peak, with full recovery and no further deaths.
**4. Lessons Learned:**
Methionine is vital for laying hens, but under normal conditions, the body absorbs it and processes it through the liver and kidneys. When methionine levels are too high, the liver may not be able to metabolize it effectively, leading to toxic buildup and organ damage. This can disrupt the hen's metabolism and result in poisoning. Most commercial feeds already provide sufficient methionine, so adding more is unnecessary and potentially harmful. Farmers should avoid over-supplementing methionine, as it can backfire and reduce productivity. Proper feeding management is key to maintaining the health and performance of laying hens.
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