Molting is a natural occurrence in the Avian species that can include a period of fasting. Animal rights groups view the longepted standard industry practice as inhumane. Based on influences from these groups and the recommendation of its scientific committee, United Egg Producers (UEP) requires members of its Animal Care Certified Program use a noneed withdrawal molting program, even though the morphological and physiological effects of this method have not been studied in depth and the existing literature provides contradictory results. Research regarding how to induce a noneed withdrawal molt has been performed using feed that is nutrient deficient or contains an additive to cease egg production. Studies have shown subsequent egg production to be comparable to hens molted using feed withdrawal. This study was designed to determine the morphological and physiological changes that occur in a noneed withdrawal molt. Two hundred hens divided into 40 groups of 3 birds each were molted in a staggered pattern so that the morphological and physiological effects of noneed withdrawal molt could be measured with identical environmental and housing variables. Data was divided into 5 sections including Control (n=5), Start (n=7), Mid-Molt (n-7), Near End (n=7), and Over (n=15). Internal organs were examined and measured. Corticosterone levels were measured to determine if noneed withdrawal molting causes less stress to hens. Pertinent blood parameters including cholesterol, glucose, O2, CO2, hemoglobin, and hematocrit were also measured. Results indicate internal organ weight changes due to noneed withdrawal molt were as expected. Decreases in the oviduct length, ovary weight, follicle weight, and follicle number indicate regression of the reproductive tract. No differences (P<0.05) were observed in corticosterone levels, suggesting that a noneed withdrawal molt does not increase stress in laying hens.
| Identifer | oai:union.ndltd.org:MSSTATE/oai:scholarsjunction.msstate.edu:td-4204 |
| Date | 13 December 2008 |
| Creators | McDonald, Ann Laster |
| Publisher | Scholars Junction |
| Source Sets | Mississippi State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
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