Year of Publication

2020

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Agriculture, Food and Environment

Department

Animal and Food Sciences

First Advisor

Dr. Anthony Pescatore

Abstract

The commercial production of pasture and free-range eggs in the United States is expanding rapidly. According to the United States Department of Agriculture Agricultural Management Assistance, in May of 2019 there were 2.6M pasture hens and 4.5M free-range hens representing 1.9% of the nation’s laying flock. There is little industry and/or academic experience with this style of production in the United States. Programs such as the European Layer Training Initiative (ELTI), which emerged in 2019, have tried to fill this void but participation from the US was low. The principal sources for guidance of commercial free-range egg production in the United States are Non-Government Organizations (NGOs) such as the American Humane, Humane Farm Animal Care, Global Animal Partnership, a limited number of dedicated academic faculty, industry associations such as United Egg Producers, and/or trial and error of individual egg companies and farms.

To provide a baseline from which humane poultry husbandry can be planned and put into action, three experiments were developed and executed with goals of examining the performance of the poultry and the production economics of an integrated approach to free-range egg production. Within these three experiments interactions among genotype, environment and management, in a commercial setting were evaluated.

The first experiment assessed whether movements of free-range laying hens were influenced by changing the locations of movable habitat enrichments, such as shade coverings, the research demonstrated moving shade in a range affected laying hen movement and location within the range. This ability to move laying hens around a range is critical to avoid overgrazing and denuding of areas within the range and giving areas of the range a chance to rest and rejuvenate. The second experiment assessed the correlation between stockman personality assessment and flock performance. Research identified a correlation between personality attributes of a stockman and flock productivity and developed a regression using production and personality parameters that yielded an 81.85% predictability of expected results. Key personality traits were emotional control and the relationship between detail orientation and assertiveness. This information is important to better identify ideal stockpeople that will optimize flock productivity. The third experiment assessed the effect of blue light compared to white light on the tonic immobility of 16-wk old female pullets during nighttime move-outs (depopulation) and transfers from a commercial pullet barn to a commercial layer barn. Tonic immobility (TI) did not differ between light treatments. Reducing TI scores at the pullet move concurrently will reduce other stress related challenges to the pullet during the move.

The research clarified aspects about humane poultry husbandry that will advance the industry and contribute to the ability of the U.S. free range egg producers to compete in a national marketplace in development, training, and application of the humane commercial production of eggs.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2020.145

Funding Information

All funding was provided by Egg Innovations, a privately-owned company, from 2016-2020.

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