Non Technical Summary
Animal Health Component
Research Effort Categories
Goals / Objectives
The table egg supply was diminished with the depopulation of almost 40 million laying hens and pullets in 2015 due to avian influenza. Due to hen house or pullet house location, no alternative was available to the commercial producers if the birds were located in an infected zone. Pullet research has greatly diminished since the early 1990¿s so suggested alternatives on how to delay the onset of lay or reduce the maturation time with today¿s genetic strains is nonexistent. Therefore, the project is designed to provide an unbiased assessment of the impact of early production molt on hen performance and well-being of pullets. Rearing: Pullets will be grown to meet the recommended body weights provided by the specific breeder management guide. Feed intake, feed:gain, and nutrient intake will be monitored throughout the rearing phase. Production: The performance will be monitored concurrently during the rearing and laying phase per experimental protocol. Data collected will include: ¿ Flock cycle (16 through 32 wks) o Feed consumption o Feed conversion ¿ Egg characteristics ¿ Egg production ¿ Egg quality ¿ Mortality ¿ Salmonella and Campylobacter spp. shedding ¿ Egg microbiology
The project will consist of Hy-Line W-36 reared as cage-free pullets from 0 to 16 weeks of age. The four experimental treatments will be implemented at 17 weeks as follows: 1) Control group (placed in aviary hen housing at 17 weeks) 2) Floor (pullet density and laying eggs in the rearing facility) 3) Temporary enrichment (pullet density, eggs in rearing, add perches and nestboxes) 4) Molt (pullet density, brought into 10% production, molted, and brought back into lay) The control group of pullets will be moved into the aviary at 17 weeks of age. Post molt initiation of lay, treatments 2 to 4 above will be moved into the laying hen facility. Four rooms with four sections of aviary per room will be utilized to house all treatments within a room. The experimental unit for all production measures and all animal-based well-being measures will be the aviary section with four sections per treatment blocked by room for statistical analysis. The flock will be terminated at 32 weeks of age. Michigan State University (MSU) will provide all animal care, as well as monitor production parameters during the production cycle, compiled and analyzed for differences amongst treatments. MSU will monitor the well-being of hens every month, plus the extra assessments during the molt phase, using an accepted standard. At each sampling period, fifteen percent of hens per treatment will be evaluated for the following: 1) percent of hens panting (as an indicator of heat stress), 2) deformation of the keel bone, 3) skin lesions, 4) plumage damage, 5) lice/mite infestation, 6) foot pad condition, 7) toe damage, 8) enlarged crops, 9) eye condition, 10) comb abnormalities, and 11) beak condition and abnormalities. Nest run eggs will be collected each Monday for shell microbial analysis. The eggs will be collected from 18 weeks to 25 weeks, week 28, and at depopulation. Samples will be sent to the Egg Safety and Quality Research Unit, USDA Agricultural Research Service, Athens, GA (ESQRU). Nest run eggs will be collected each Tuesday and shipped to ESQRU for egg quality evaluation. The evaluation will include: volume of shell, shape index, static compression shell strength, shell thickness, Haugh unit, vitelline membrane strength and elasticity, and yolk index. For physical egg quality, eggs will be collected weekly from 18 to 32 wks of age, as eggs are available. Nest run eggs will be collected each Wednesday for egg component weights by MSU. The eggs will be weighed and component weights will be measured on albumen, shell, and yolk. Eggs will be collected weekly from 18 to 32 wks of age, as eggs are available. At day of hatch, sterile moistened sponges will be utilized to swab chick box papers for microbial analysis (n=30). Subsequent monthly fresh fecal pools will be collected through 32 weeks of age (4 fecal composites per treatment/housing room). Fresh fecal pools will be sent to ESQRU for microbial analysis on Tuesdays.