About

Dr. Allison Pullin’s research investigates how management practices and housing design influence the welfare of farmed poultry. She takes an interdisciplinary approach by utilizing tools in animal behavior, health, and physiology to assess welfare. Dr. Pullin applies science-based assessments of welfare on farms through her role as a PAACO-certified poultry welfare auditor. Prior to joining NC State, she completed her B.S. and M.S. degrees in Animal Science at The Ohio State University, and she earned her Ph.D. at University of California, Davis in Animal Behavior.

Research topics

• Animal science
• Biology
• Engineering
• Mathematics
• Structural engineering
• Fishery

Selected publications

• The effect of housing system and broiler breed on meat quality1

  Poultry Science · 2026-04-27

  articleOpen access

  This study investigated the effects of the silvopastoral (SP) rearing system compared with a conventional (CV) indoor system, along with the influence of broiler breed (fast-growing, FAST vs. slow-growing, SLOW), on carcass traits (yields), meat quality, myopathy incidence, fatty acid profile, oxidative stability (TBARS), and sensory attributes. A 2 × 2 factorial design was conducted, using 250 birds per treatment, with 5 replicate pens (50 birds/pen). For data collection, 10 birds were selected from each pen for processing, giving a total of 5 replicates and 50 samples per treatment. FAST consistently exhibited superior carcass and breast yields, while SLOW had minimal breast muscle myopathies, regardless of the system. Several physicochemical traits were primarily influenced by the breed, with SLOW's breast exhibiting a greater content of connective tissue and shear force. In comparison, FAST exhibited greater moisture content. The housing system influenced lipid composition and oxidative stability, with SP meat exhibiting lower saturated fatty acid content than CV (40.16% vs. 42.04%) and reduced TBARS values (1.50 vs. 1.59 mg MDA/kg). However, the effect of SP on FAST was limited, as cooking loss did not differ between SP and CV systems (30.91% vs. 32.76%). Sensory results showed minimal differences; meat from CV birds was rated slightly juicier, while SLOW's meat was described as chewier and gummier. Overall, trade-offs were identified between yield performance and meat quality; meat from fast-growing birds had greater production efficiency but exhibited a greater incidence of muscular abnormalities. SP production demonstrated the potential to enhance certain meat quality traits without compromising sensory acceptance, albeit at a lower yield expense.

  PublisherDOI

• Handling and loading market-ready turkeys – Focus groups exploring the perspectives of live haul crew workers in the turkey industry

  The Journal of Applied Poultry Research · 2025-05-09 · 1 citations

  articleOpen accessSenior authorCorresponding

  Improper handling and loading of market-ready turkeys during live haul presents significant challenges in the U.S. turkey industry. Bird injuries, such as bruises, scratches, and/or fractured or broken bones compromise animal welfare and lead to economic losses. However, the factors contributing to these handling challenges remain understudied. We aimed to identify barriers to implementing proper handling and loading techniques for market-ready turkeys through focus groups with commercial live haul crews. Participants identified three key themes: animal, farm, and human factors. Animal factors, such as bird sex, age, weight, and mobility, required crew members to modify handling strategies and varied the efficiency of live haul. The farm factors centered on the importance of preparing the barn environment for live haul. Adjusting lighting, ensuring good litter quality, scheduling nighttime shifts, using loading equipment correctly, and maintaining stable temperatures improve bird movement. Human factors included employee training methods, where informal training was the primary way in which crew members learned how to perform their tasks; the physical demands of the job, especially in challenging situations; and specific handling strategies to efficiently move birds and minimize injuries to animals and crew members. Animal, farm, and human factors are often interconnected, which compounds the complexity of ensuring proper animal handling for live haul. Future research in formal training, the design of farms, loading equipment, and personal protective equipment may mitigate the effects of these factors. Additionally, proactive teamwork and communication amongst veterinarians, producers, and live haul crews would better prepare farms for live haul.

  PublisherDOI

• The effect of feed and water provision strategies on broiler breeder pullet performance and welfare

  Frontiers in Veterinary Science · 2025-08-08

  articleOpen accessSenior authorCorresponding

  Feed restriction is common in the broiler breeder industry to optimize health and reproduction. However, this practice has been associated with increased drinking behavior, leading to water spillage, higher litter moisture, and footpad lesions. Consequently, parts of the industry have adopted water restriction protocols. This study aimed to evaluate how different combinations of feed and water restriction affected drinking behavior, welfare, and performance indicators in broiler breeder pullets. At 1 day of age, 960 Cobb 500 FF pullets ( Gallus gallus domesticus ) were randomly allocated to one of four treatments: skip-a-day feeding with ad libitum water (SAD + ADLIB), every-day feeding with ad libitum water (ED + ADLIB), skip-a-day feeding with 3 h daily water restriction (SAD + WR), and every-day feeding with 3 h daily water restriction (ED + WR). All data were analyzed with generalized linear or linear mixed effects models in R Studio. Drinking behavior was observed at 16 and 22 weeks at an hour after feeding (HAF), when water was turned off for SAD + WR and ED + WR (12:00), and when water access resumed for SAD + WR and ED + WR (14:30). The ED pullets displayed more drinker use at HAF at both ages ( p = 0.014), while SAD treatments performed more drinker use at 12:00 ( p < 0.0001) and 14:30 ( p = 0.0028) at 22 weeks. The WR pullets displayed more drinker use than ADLIB pullets at HAF and 14:30 ( p < 0.0001), while ADLIB pullets performed more drinker use at 12:00 ( p = 0.008). Water use (g/bird) was higher in ED + ADLIB pullets at 16 and 22 weeks compared to SAD+ADLIB pullets ( p = 0.042), but WR groups did not differ ( p > 0.05). Litter moisture under drinker lines reflected water use patterns, with ED pens wetter at 16 weeks ( p = 0.0011), but SAD pens unexpectedly had higher moisture at 22 weeks ( p = 0.011). General pen area litter was wetter in SAD and ADLIB groups ( p = 0.0036). Footpad scores did not differ among treatments ( p > 0.05). Body weight and uniformity did not drive water use. Overall, feeding program significantly influenced water use and behavior. Compensatory drinking in WR birds may indicate a welfare concern. Future research should explore measures of satiety and hydration to better understand the behavioral and physiological impacts of water restriction.

  PublisherOA PDFDOI

• Research note: Stress responses in different genetic strains of laying hens housed in a cage-free environment

  Poultry Science · 2025-05-15 · 1 citations

  articleOpen access

  Cage-free systems offer hens the opportunity to perform natural behaviors, but they also expose birds to more frequent environmental and social stressors, which can impact welfare. Therefore, this study assessed stress responses in four laying hen strains housed in a cage-free environment. Hy-Line W36 White, H&N White, Hy-Line Brown, and Bovan Brown laying hens were evaluated through plasma corticosterone levels, heterophil lymphocyte ratios, and heat shock proteins (HSP) 70, 90a, and 90b gene expression at five distinct time points throughout the laying hen cycle. There were no differences among these parameters found attributable to genetic strain. However, all strains exhibited similar stress responses at critical time points throughout the lay cycle. HSP70 expression was highest at the end of lay (p < 0.0001), HSP90a at the start of lay (p < 0.0001), and both HSP90b and heterophil lymphocyte ratios at peak lay (p < 0.0001), suggesting a potential relationship between the two. Corticosterone levels remained consistent across both genetic strains and time points. Therefore, although no distinctions were observed among genetic strains, the variability in stress levels over time provides insight into factors impacting the welfare of hens throughout egg production.

  PublisherDOI

• Tool-based euthanasia methods for broiler chicks: Evaluating welfare outcomes of Iris and Kelly scissors

  Poultry Science · 2025-11-08

  articleOpen accessSenior authorCorresponding

  The most common euthanasia method for poultry is manual cervical dislocation (CD), but it is challenging to consistently perform in young chicks due to their small body size. Tool-assisted CD may offer an alternative. Our objective was to evaluate the efficacy of two tool-assisted CD methods with Iris (ICD) and Kelly (KCD) scissors compared to manual CD in 1-day-old (1DOA) and 7-day-old (7DOA) broiler chicks. Chicks were randomly and equally allocated to one of three euthanasia treatments: CD (n=20 1DOA, n=20 7DOA), ICD (n=20 1DOA, n=20 7DOA), and KCD (n=20 1DOA, n=20 7DOA). All euthanasia methods effectively rendered chicks insensible, followed by respiratory and cardiac arrest on the first attempt, with cardiac cessation occurring within 52 to 253 sec. Chicks euthanized with CD achieved cardiac arrest sooner at both ages (p=0.0154), displayed less mouth gaping at both ages (p=0.0006), lost the pupillary light reflex faster at 1DOA (p=0.0177), and displayed shorter clonic convulsions (p=0.0331) and feather erection (p=0.0538) at 7DOA compared to chicks euthanized with ICD and KCD. However, CD also displayed the highest macroscopic laceration score (p<0.0001) and subcutaneous hemorrhaging (p<0.0001) than KCD and ICD, and CD was the only method to result in decapitation. The ICD method achieved a similar consistency as CD in the site of vertebral separation, with the majority of separations occurring between C1-C2 vertebrae for both methods (p=0.0046). The KCD method resulted in lower separations (C2-C3 vertebrae; p<0.0001) and a higher incidence of vertebral and crushed fractures than CD and ICD (p=0.0303). Taken together, although all methods were successful in rendering chicks insensible, the CD resulted in insensibility metrics occurring sooner, particularly at 7DOA. However, the CD method demonstrated more lacerations and greater risk for decapitation, which may be more emotionally aversive to the person performing euthanasia. The ICD method offered an alternative to achieve similar consistency in cervical dislocation and brain trauma while minimizing macroscopic lesions and fractures.

  PublisherDOI

• Outdoor access versus conventional broiler chicken production: Updated review of animal welfare, food safety, and meat quality

  Poultry Science · 2025-02-17 · 14 citations

  reviewOpen accessSenior authorCorresponding

  Growing consumer demand for animal welfare and environmental sustainability in the poultry industry is driving the adoption of outdoor access for broiler chickens in the United States. However, shifting to outdoor access from conventional housing may pose tradeoffs for animal welfare, meat quality, and food safety. Research comparing conventional and outdoor access housing on these attributes has not been reviewed for approximately a decade. We reviewed and compared animal welfare, food safety, and meat quality outcomes in conventional versus outdoor access broiler production, focusing on recent research. Despite the prevailing notion that outdoor access improves animal welfare due to more behavioral opportunities, the utilization of the range is highly variable and affected by a variety of environmental, management, and bird characteristics. Outdoor areas containing vegetation and tree cover promote use by the birds, and slow-growing breeds appear to be best suited for these production systems. Typically, welfare-related health outcomes (i.e., footpad dermatitis, mortality, and lameness) are improved with outdoor access. However, birds with outdoor access are at a higher risk for endo- and ectoparasitic infections. Antimicrobial resistance is typically lower on outdoor access farms, and birds with outdoor access have more diverse microbiomes. There are mixed results for the prevalences of Salmonella and Campylobacter between conventional and outdoor access farms. Meat quality varies in complex ways related to rearing system, age, breed, diet, and behavior. Meat from outdoor access broilers may present better taste or flavor, yet there can be tradeoffs for texture and moisture, particularly for older, slower-growing breeds that are typical of outdoor access production. Taken together, studies to date indicate multiple benefits and tradeoffs for animal welfare, food safety, and meat quality. Variations in management between farms and certification criteria result in inconsistent outcomes. The majority of outdoor access research has been conducted outside of the United States. Region-specific research accounting for geography, climate, and available breeds would be beneficial for improving outdoor access production outcomes in the United States.

  PublisherDOI

• The influence of genetic strain on fear and anxiety responses of laying hens housed in a cage-free environment

  Poultry Science · 2025-05-01 · 1 citations

  articleOpen accessSenior author

  Cage-free environments provide more behavioral opportunities for hens than cages, but fear responses in such open housing can lead to injuries and challenging human-animal interactions. This study evaluated the impact of genetic strain on fear and anxiety responses in two brown and one white genetic strain of laying hens: Hy-Line Brown (HB), Bovan Brown (BB), and H&N White (HN). Hens were assessed at the start of lay and peak lay through the inversion and attention bias tests, along with thermal imaging and core body temperature measurements to assess stress-induced hyperthermia. During the inversion test, HB hens performed significantly more wing flaps than other strains (p=0.012), while BB hens exhibited more vocalizations than HN hens (p=0.0041). Thermal imaging revealed that at the start of lay, HB and HN hens had higher maximum comb temperatures than BB hens (p<0.0001), but HB hens had lower temperatures at peak lay (p=0.027). BB and HN hens had higher core body temperatures at 4- and 5-minutes post-inversion (p<0.0001). In the attention bias test, HB and BB hens were more likely to resume eating and showed increased head bobbing as they aged, whereas HN hens were less likely to resume eating but maintained high head bobbing (p=0.017; p=0.00056). BB hens had the lowest average eye and maximum comb temperatures 3.5 to 4.5 min post-startle at the start of lay (p<0.05), white HN hens had the highest average eye and comb temperatures (p<0.0001) and higher average eye temperatures than BB at peak lay (p=0.026). Finally, HN hens had higher core body temperatures than HB hens at both the start of lay and peak lay (p=0.041; p=0.046). These results indicate that brown and white strains differ in their responses to fear and anxiety, with brown strains being more behaviorally responsive and white strains showing greater physiological stress. These strain-specific coping mechanisms provide insight into how hens may react to stressors in cage-free environments, aiding in strain selection for producers.

  PublisherDOI

• The influence of genetic strain on production and egg quality amongst four strains of laying hens housed in a cage-free environment

  Poultry Science · 2025-03-19 · 5 citations

  articleOpen access

  As the United States egg industry transitions towards cage-free production, genetic strains must be evaluated in their performance in these alternative environments. Transitioning strains that were selected for caged production may elicit challenges in their adaptation to alternative systems, so it cannot be assumed that egg production and quality parameters are comparable in various environments. White strains are historically associated with caged production while brown strains typically occupy cage-free systems. Therefore, the aim of this study was to evaluate the influence of genetic strain on egg production and quality in a cage-free environment. Hy-Line W-36 White, H&N White, Hy-Line Brown, and Bovan Brown laying hen strains were evaluated through numerous egg production and quality parameters throughout the entirety of a lay cycle. H&N White hens in this study were the lowest producing strain demonstrated by producing the least amount of eggs per hen, having the lowest hen-day egg production (p < 0.0001), producing the fewest USDA grade A eggs (p = 0.0023), and the most check eggs (p = 0.0006). However, the Bovan Browns were the least efficient strain as this strain consumed the most feed and had the lowest feed conversion ratio (p < 0.0001). Overall, both white strains demonstrated poorer egg quality compared to brown strains. Hy-Line W-36 White hens had the lowest albumen height, Haugh unit score, yolk color, and yolk weight (p < 0.0001). H&N Whites had the lowest vitelline membrane strength, shell weight, and shell thickness (p < 0.0001). In conclusion, the Hy-Line Brown hens may be better suited for cage-free production based on overall greater egg production and quality metrics compared to the three other strains used in this study. Therefore, this research demonstrates that genetic strain did influence cage-free laying hen performance.

  PublisherDOI

• Efficacy of a novel cervical dislocation tool for humane euthanasia of broilers and broiler breeders

  Poultry Science · 2024-01-10 · 8 citations

  articleOpen access

  Euthanasia is an essential task performed daily on commercial poultry farms around the world to safeguard animal welfare. Manual cervical dislocation (MCD) is the most common euthanasia method but can be challenging to perform given the physical strength required to implement this technique. Therefore, the objective of this study was to evaluate the efficacy of a novel cervical dislocation tool (NCDT) compared to MCD. A total of 60 Ross 308 chickens (6-wk old) and 60 Ross 706 parent stock breeders (21-wk old) were enrolled in the study. Birds were sexed, blocked by body weight, and allocated to 1 of 2 treatments: 1) MCD and 2) NCDT. Immediately following euthanasia application, insensibility, and death were monitored. Once death was confirmed, gross evaluation, radiograph, and macroscopic/microscopic scoring were performed. Both euthanasia methods were 100% effective in achieving insensibility followed by cardiac and respiratory arrest in both age groups. In 6-wk-old broilers, there were no differences in insensibility measures or location and severity of the dislocation site by treatment. The NCDT treatment group showed an increased frequency of fractures located at the tooth-like process that projects from the cranial aspect of the centrum of the axis (dens) but had no impact on bird insensibility. For parent stock, differences in nictitating membrane reflex (NMR) and laceration scores for birds euthanized with NCDT were found and likely associated with additional force exerted with the tool. The NCDT is a promising replacement for MCD and future work should address the development of free and accessible training materials for on-farm use.

  PublisherDOI

• Effects of pullet housing on bone development in aviary-housed Dekalb White hens

  Poultry Science · 2024-08-22 · 4 citations

  articleOpen access

  The skeletal health of laying hens improves when birds are given opportunities to perform load-bearing movements with elevated structures, such as perches. We investigated how early access to elevated structures varying in complexity and height would affect bone quality and subsequent keel bone fractures in a layer multitiered aviary. Female Dekalb White pullets were reared in floor pens furnished with floor perches (FL), single-tiered aviaries (ST), or 2-tiered aviaries (TT; n = 5 pens/treatment) through 16 wk of age. At 17 wks, all structures were replaced with identical multitiered layer aviaries. The keel, both tibiae, and both humeri were collected from 60 euthanized birds from each rearing treatment at 8, 16 and 30 wk of age, and analyzed with dual X-ray absorptiometry (DEXA) for bone mineral density and length. At 18, 26, 28, and 30 wk of age, 10 focal hens/pen were radiographed repeatedly and the presence, severity of keel bone fractures were assessed with a tagged visual analogue scale. The number of fractures was also recorded. At 16 wk of age, FL pullets had lower BMD of the tibia (P = 0.003), keel (P = 0.013), and humerus (P = 0.004) compared to ST and TT pullets. Most of the observed treatment differences disappeared after pullets were transferred to the aviary. BMD continued to increase for all hens through 30 wk of age. Pullet rearing did not affect the presence or severity of keel bone fractures, or number of new fractures incurred between ages (P > 0.05). The prevalence and severity of keel bone fractures increased between 26 to 28 wk and remained high to 30 wk of age (P < 0.0001). Hens experienced more new fractures between 26 to 30 wk than between 18 to 26 wk of age (P = 0.0046). The effects of pullet housing on bone quality were short-term when hens had access to adult housing with multiple opportunities for load-bearing movements. Keel fractures with minor severity were high in prevalence reflecting the use of radiography to assess this injury.

  PublisherDOI

Frequent coauthors

• Christina Rufener

  Agroscope

  20 shared

• Richard A. Blatchford

  University of California, Davis

  20 shared

• Maja M. Makagon

  Animal Welfare Institute

  20 shared

• Kristina Horback

  8 shared

• Claire T. Jones

  Animal Welfare Institute

  8 shared

• Monique Pairis-Garcia

  North Carolina State University

  5 shared

• John F. Tarlton

  University of Bristol

  4 shared

• Michael J. Toscano

  University of Bern

  4 shared

Education

• Ph.D., Animal Behavior

  University of California, Davis

  2022

• Master of Science, Animal Sciences

  The Ohio State University

  2017

• Bachelor of Science, Animal Sciences

  The Ohio State University

  2014