Initial program focus: As with many animal-sourced foods, the global demand for eggs and pork products is expected to increase significantly in the next several decades and production practices are changing rapidly, often in response to consumer preferences. Given the wide variety of animal breeds, husbandry practices, and additional factors that can impact animal welfare and production, it is vital that researchers in the United States provide cutting-edge information to support farmers as they transition to new practices. FFAR is committed to funding innovative science that addresses concerns that are an issue for both animal welfare and production efficiency. FFAR will consider additional issues for future funding.

Cage-free egg production: The top 25 U.S. grocers and the majority of the top 20 fast food chains in the U.S. have committed to sourcing eggs from cage-free poultry by 2025 or sooner. The U.S. Department of Agriculture (USDA) estimates that to meet these cage-free commitments, the egg industry will need to convert most current production systems to cage-free, at which time > 100 million layer hens will be housed in aviary systems (USDA Agricultural Marketing Service). However, there are biological and operational challenges associated with cage-free egg production. One challenge in cage-free production is minimizing keel bone fractures, which cause pain, decreased egg production, reduced growth efficiency and reduced carcass value (Nasr, 2012). Estimates of the prevalence of keel fractures in Europe and Canada (where cage-free production is more common) range from approximately 50-90% (Nasr, 2012; Kapelli, 2011; Petrik, 2015; Rodenburg, 2008; Wilkins, 2011) and fractures are reported to occur at higher rates in cage-free housing systems (Petrik, 2015; Sandilands, 2009).

Economic impact of keel fractures: Keel fractures have a major negative economic impact on American farmers, who produced approximately 100 billion eggs from 375 million layer hens in 2016 (USDA-ERS). Hens with keel fractures produce significantly fewer eggs with lower egg quality scores, and these hens consume dramatically more feed than those without fractures (Nasr, 2012), resulting in higher costs and diminishing returns for egg producers (Sumner, 2011). Research supported by FFAR will be critical to preserving consumer confidence in U.S. egg production practices and addressing hidden costs as the egg industry moves towards cage-free production.

Potential causes of keel fractures in laying hens: The keel fracture problem is complex and not due simply to animal breeding, as frequently assumed. Bone health is influenced by many factors including genetics, diet and nutrition, pullet rearing-practices, housing design and other factors such as gut health. Keel fractures have been documented in virtually all housing systems and breeds (Caey-Trott, 2017; Nasr, 2012; Kapelli, 2011; Petrik, 2015; Rodenburg, 2008; Wilkins, 2011; Petrik, 2015; Sandilands, 2009). Acclimating birds to aviary housing from a young age (Casey-Trott, 2017) and housing / perch design may play a role in reducing the prevalence of fractures (Sandilands, 2009; Stratman, 2015). Interestingly, most studies on the prevalence of keel fractures have been conducted in Europe and Canada, where flock sizes are typically smaller than in the US, and housing design, rearing practices and hen breeds may differ.

Swine castration: Castration of piglets is performed to prevent the development of undesirable meat flavors caused by male sex hormones and to make animal care safer by reducing male aggressive behaviors. Blood cortisol levels and behavioral indicators indicate that the procedure is painful (Carroll, 2006; Hay 2003; Hensch, 2011). Local anesthetics are not labeled for use in swine, are of short duration, and can be expensive and difficult to administer. Limited alternatives such as immuno-castration are not widely used for a number of reasons including the danger to those administering the drug, cost and logistical difficulties of administration including housing and handling intact males. FFAR’s goal in addressing the castration issue is to promote game-changing research that can be applied across species to address welfare and improve productivity.


  • Carroll et al. (2006) Hormonal profiles, behavioral responses, and short-term growth performance after castration of pigs at three, six, or twelve days of age. J Anim Sci, 84:1271-1278
  • Casey-Trott et al. (2015) Methods for assessment of keel bone damage in poultry. Poult Sci, 94 (10): 2339-2350
  • Casey-Trott, et al. (2017) Rearing system affects prevalence of keel-bone damage in laying hens: a longitudinal study of four consecutive flocks.Poult Sci,  doi: 10.3382/ps/pex026
  • Farm Animal Welfare Council. (2010) Opinion on Osteoporosis and Bone Fractures in Laying Hens London.
  • Farm Animal Welfare Council. (2013) Keel bone fractures in laying hens.
  • Harlander-Matauschek, et al. (2015) Causes of keel bone damage and their solutions in laying hens. World’s Poultry Science Journal, 71(3): 461-472. ISSN 0043-9339.
  • Hay et al. (2003) Assessment of pain induced by castration in piglets: behavioral and physiological responses over the subsequent 5 days. Appl Anim Behav Sci, 3:201-218
  • Hensch et al. (2011) Using Serum Cortisol to Distinguish Between Acute Stress and Pain Response Following Castration in Piglets. Animal Industry Report: AS 657, ASL R2638.
  • Käppeli et al. (2011) Prevalence of keel bone deformities in Swiss laying hens. Br Poult Sci, 52: 531-536. pmid:22029778
  • Nasr et al. (2012) The effect of keel fractures on egg production, feed and water consumption in individual laying hens. Animal Welfare, 21: 127-135 ISSN 0962-7286
  • Petrik et al.(2015) On-Farm Comparison of Keel Fracture Prevalence and Other Welfare Indicators in Conventional Cage and Floor-Housed Laying Hens in Ontario, Canada. Poult Sci, 94 (4): 579-585
  • Rodenburg et al. (2008) Welfare assessment of laying hens in furnished cages and non-cage systems: an on-farm comparison. Animal Welfare, 17(4): 363-37
  • Sandilands et al. (2009) Providing laying hens with perches: fulfilling behavioural needs but causing injury? British Poultry Science, 50: 395-406.
  • Stratmann et al. (2015) Soft Perches in an Aviary System Reduce Incidence of Keel Bone Damage in Laying Hens. PLosOne,
  • Sumner et al. (2011) Economic and market issues on the sustainability of egg production in the United States: Analysis of alternative production systems.Poult Sci, 90 (1): 241-250. doi: 10.3382/ps.2010-0082
  • USDA-ERS data:
  • Wilkins et al. (2011) Influence of housing system and design on bone strength and keel bone fractures in laying hens. Vet Rec, 169: 414. pmid:21862469