The Effects of Using Alfalfa-based Molt Diet Compared with Feed Deprivation on Blood Parameters Changes During Molt Period and Post-Molt Performance of Commercial Laying Hens

Induced molting is a process that stimulates natural molting events. When birds return to full feed, a new plumage develops and the birds resume egg peroduction at a higher rate with better egg quality. Induced molting extends the productive liffe of commercial chicken flocks and results in substantial reduction in the number of chickens needed to produce the nation's egg supply. However, molting induced by feed withdrawal (FW) case discomfort and stress in hens. Stress causes a general deterioration of the well-being of chickens, usually involving a cascade of physiological adaptive responses that include changes in plasma levels of blood metabolites. The aim of the present study was determine the effects of alfalfa and feed deprivation on molt performance, some blood parameters changes during molt period and post-molt production of commercial laying hens. This experiment was carried out trough a completely randomized design with 108 of Hy-line W-36 laying hens at the 74 week of age in 3 treatments and 6 replicates (with 6 birds in each replicate). The using treatments for 12 days molt period were included: 1- control group fed with layer ration (FF), 2- feed withdrawal group (FW), 3- group fed with 90% alfalfa and 10% layer ration (A90). Blood sample was collected on day 0 (before any treatments began), 3, 6, 9 and 12 of molting period and serum concentration of triglyceride, cholesterol, glucose, calcium and uric acid were measured. At the end of this period, all hens return to the layer ration. Egg production was monitored for 12 weeks after the end of the molting period. Results indicated that, triglyceride, calcium and uric acid levels were generally lower in molted hens compared with nonmolted hens during the molt period. On days 3 and 6 of molting, FF hens exhibited higher blood triglyceride levels than FW and A90 hens. In addition, the triglyceride levels measured in the A90 hens were significantly lower (P