A Study of the Efficacy of Probiotic Supplementation to Reduce Aggressive Feather Pecking Behavior in Laying Hens
Abstract
Feather pecking behavior poses a significant challenge within the egg production industry. A recent shift in housing structure and management style has led to an increased incidence of this destructive behavior which negatively effects animal welfare and economic returns. The pulling of feathers results in pain, injury and increased rates of mortality and cannibalism. It also compromises efficiency as chickens denuded by feather pecking require more feed to maintain body temperature resulting in decreased food conversion ratios. Although this deleterious behavior is present in all housing systems it is amplified in systems that congregate large numbers of hens together allowing for increased contact between conspecifics.
Many studies indicate that behavior can be influenced by the gut microbiome, especially during critical stages of early development. This is relevant to the egg industry because in an effort to limit bacterial pathogens, hens are hatched in “clean environments” excluding them from exposure to early beneficial microflora supplied by healthy adult animals. Hen development and early intestinal microbial colonization occur in concert providing a framework for host function and behavior throughout life.
The current study recognizes this relationship and explores the use of continuous flow (CF) and electron beam irradiated continuous flow (EB) cultures to encourage early intestinal colonization with the intent of reducing feather pecking behavior. These cultures were evaluated for their effectiveness using a chicken model. Three treatments; CF, EB and a treatment that contained only sterilized water (WR) were administered as weekly supplements to birds at day of hatch and throughout the first 16 weeks of life. Behavioral testing, physiological testing and ii video observation of pen behaviors were used to identify any significant differences between treatments.
Of the results garnered from this study, very few significant differences were found between treatment groups. No difference was found in plasma corticosterone levels or hen performance during the tonic immobility test. One of the few significant differences identified through video observation of home pen behaviors was the number of drinks (p = 0.02) performed by hens in the WR treatment group. The WR treatment group also neared significance in the number of times hens were observed standing (p = 0.07) in the home pen and in latency to first step (p = 0.09) as evaluated using the open-field test. The number of gentle feather pecks delivered was also found to be significant in the WR group, however this result is likely biased due to the number of zeroes included in this data set and requires a larger study in order to confirm this observation. Overall this study was unable to identify any differences between treatment groups but provided evidence that suggests that further research is prudent.
Ultimately, this work supports further exploration into the area of probiotic culture-based solutions for altering laying hen behavior in a commercial setting.
Subject
Continuous Flow CultureElectron Beam Technology
eBeam
Probiotic
Injurious Feather Pecking
Aggressive Feather Pecking
Chemostat
Laying Hen Behavior
Citation
Sullivan, John Patrick (2020). A Study of the Efficacy of Probiotic Supplementation to Reduce Aggressive Feather Pecking Behavior in Laying Hens. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /192490.