@article{wray-cahen_bodnar_rexroad_siewerdt_kovich_2022, title={Advancing genome editing to improve the sustainability and resiliency of animal agriculture}, volume={3}, url={https://doi.org/10.1186/s43170-022-00091-w}, DOI={10.1186/s43170-022-00091-w}, abstractNote={Abstract Animal agriculture faces unprecedented challenges, including the need to increase productivity to meet increasing demands for high quality protein while combating increasing pest and disease pressures, improving animal welfare, adapting to a changing climate, and reducing the environmental impact of animal agriculture. Genome editing, in concert with other existing technologies, has the potential to accelerate these efforts. The U.S. Department of Agriculture (USDA) supports research focused on delivering scientific solutions to these national and global agricultural challenges and transferring these solutions to farmers. Genome editing, along with a broad range of other tools, provides an opportunity for scientists, breeders, farmers, and ranchers to meet these challenges and provides additional benefits for society, including healthier and more resilient livestock, while reducing agriculture’s impact on the environment. Farmers and ranchers need a full toolbox of existing and innovative options. However, they will not be able to access these tools unless flexible approaches are in place that encourage innovation and allow safe innovations to be used on farms. Genome editing can help us achieve these goals only if global regulatory and policy approaches allow their use in agricultural breeding programs and deployment to farms. The global regulatory landscape for products of genome editing is rapidly evolving, with an increasing number of countries focusing more on characteristics of products and whether they could be achieved by conventional breeding, rather than the technologies used to create them. The livelihoods of people along the agricultural value chain depend upon countries’ regulatory and policy choices; regulatory approaches and how they are applied have a dramatic impact in determining what products are developed and who can afford to use these new biotechnologies. We need to step forward and continue the momentum towards regulatory approaches that encourage innovation to ensure continued access to a safe, abundant, and affordable food supply for future generations.}, number={1}, journal={CABI Agriculture and Bioscience}, publisher={Springer Science and Business Media LLC}, author={Wray-Cahen, Diane and Bodnar, Anastasia and Rexroad, Caird, III and Siewerdt, Frank and Kovich, Dan}, year={2022}, month={Dec} }
 @article{siegel_barger_siewerdt_2019, title={Limb Health in Broiler Breeding: History Using Genetics to Improve Welfare}, volume={28}, ISSN={1056-6171}, url={http://dx.doi.org/10.3382/japr/pfz052}, DOI={10.3382/japr/pfz052}, abstractNote={Recent years have seen commercial broilers reach market weights at systematically younger ages. These broilers have more efficient growth rates and higher meat yields due to advances in breeding programs and improvements in poultry husbandry, health, and nutrition. Nonetheless, some critics have voiced concerns with possible negative impacts on the skeletal integrity of broilers. To address these concerns, we provide in this paper time trends of breeding values for 11 to 14 yr for 5 skeletal (limb) health traits in broilers of 3 pedigree pure lines. Results presented are based on well over a million chickens per line. Of the 5 traits, 4 had low heritabilities with the other being low to moderately heritable. Yet through intense and persistent selection, incidence of limb issues has not worsened and has declined in 4 of the traits.}, number={4}, journal={Journal of Applied Poultry Research}, publisher={Elsevier BV}, author={Siegel, P.B. and Barger, Kate and Siewerdt, Frank}, year={2019}, month={Dec}, pages={785–790} }
 @article{ventura_siewerdt_estevez_2012, title={Access to Barrier Perches Improves Behavior Repertoire in Broilers}, volume={7}, ISSN={1932-6203}, url={http://dx.doi.org/10.1371/journal.pone.0029826}, DOI={10.1371/journal.pone.0029826}, abstractNote={Restriction of behavioral opportunities and uneven use of space are considerable welfare concerns in modern broiler production, particularly when birds are kept at high densities. We hypothesized that increased environmental complexity by provision of barrier perches would help address these issues by encouraging perching and enhancing use of the pen space across a range of stocking densities. 2,088 day-old broiler chicks were randomly assigned to one of the following barrier and density treatment combinations over four replications: simple barrier, complex barrier, or control (no barrier) and low (8 birds/m2), moderate (13 birds/m2), or high (18 birds/m2) density. Data were collected on focal birds via instantaneous scan sampling from 2 to 6 weeks of age. Mean estimates per pen for percent of observations seen performing each behavior, as well as percent of observations in the pen periphery vs. center, were quantified and submitted to an analysis of variance with week as the repeated measure. Barrier perches, density and age affected the behavioral time budget of broilers. Both simple and complex barrier perches effectively stimulated high perching rates. Aggression and disturbances were lower in both barrier treatments compared to controls (P<0.05). Increasing density to 18 birds/m2 compared to the lower densities suppressed activity levels, with lower foraging (P<0.005), decreased perching (P<0.0001) and increased sitting (P = 0.001) earlier in the rearing period. Disturbances also increased at higher densities (P<0.05). Use of the central pen area was higher in simple barrier pens compared to controls (P<0.001), while increasing density above 8 birds/m2 suppressed use of the central space (P<0.05). This work confirms some negative effects of increasing density and suggests that barrier perches have the potential to improve broiler welfare by encouraging activity (notably by providing accessible opportunities to perch), decreasing aggression and disturbances, and promoting more even distribution of birds throughout the pen space.}, number={1}, journal={PLoS ONE}, publisher={Public Library of Science (PLoS)}, author={Ventura, Beth A. and Siewerdt, Frank and Estevez, Inma}, editor={Mettke-Hofmann, ClaudiaEditor}, year={2012}, month={Jan}, pages={e29826} }