@article{chadwick_malheiros_oviedo_cordova noboa_quintana ospina_alfaro wisaquillo_sigmon_beckstead_2020, title={Early infection with Histomonas meleagridis has limited effects on broiler breeder hens' growth and egg production and quality}, url={http://www.sciencedirect.com/science/article/pii/S0032579120303230}, DOI={https://doi.org/10.1016/j.psj.2020.05.020}, abstractNote={Abstract A study was conducted to determine differences between Histomonas meleagridis–infected and control pullets based on disease signs, hen growth, and egg production and quality. Ross 708SF females were weighed and then placed in pens on the day of hatch (92 chicks/pen). At 25 D, 4 pens were infected with H. meleagridis in the cloaca, whereas 4 pens were control. At 5, 10, and 20 D after inoculation, 5 birds per pen (2 birds per pen at 20 D) were subjectively scored for blackhead disease. Birds were feed restricted based on BW and/or egg production. Individual BW were collected at 3, 5, 13, 15, 20, and 64 wk. Egg production was recorded at 24–63 wk. Egg quality was measured at 30, 34, 39, 42, and 56 wk and included shell and vitelline membrane strength, shell thickness, egg weight, and Haugh units. Hatchability was measured at 27, 37, and 60 wk and fertility at 27 and 37 wk. Treatment effects were determined by JMP Pro 14 using GLM with means separated using the Student t test (P ≤ 0.05). Cecal lesions were apparent on 5, 10, and 20 D and liver lesions on 10 and 20 D for the infected birds. The control had no histomoniasis lesions. Flock uniformity differed on wk 13 and 20 (P = 0.04; 0.04). Infected birds weighed less at 64 wk (P = 0.002). The onset of lay was not delayed. Infected birds produced more eggs during 1 period (P = 0.02). The infected birds produced heavier eggs at 30 wk (P = 0.04), eggs with a stronger and thicker shell at 42 wk (P = 0.05, 0.03), and eggs with a stronger vitelline membrane at 56 wk (P = 0.049). Hatchability and fertility did not differ (P > 0.05). H. meleagridis was observed in the infected birds' cecal samples at trial termination. This study indicates early infection with H. meleagridis has limited effects on pullet egg production and quality.}, journal={Poultry Science}, author={Chadwick, Elle and Malheiros, Ramon and Oviedo, Edgar and Cordova Noboa, Hernan Alejandro and Quintana Ospina, Gustavo Adolfo and Alfaro Wisaquillo, Maria Camila and Sigmon, Christina and Beckstead, Robert}, year={2020} }
 @article{chadwick_malheiros_oviedo_noboa_ospina_wisaquillo_sigmon_beckstead_2020, title={Early infection with Histomonas meleagridis has limited effects on broiler breeder hens' growth and egg production and quality}, url={https://doi.org/10.1016/j.psj.2020.05.020}, DOI={10.1016/j.psj.2020.05.020}, abstractNote={Abstract A study was conducted to determine differences between Histomonas meleagridis–infected and control pullets based on disease signs, hen growth, and egg production and quality. Ross 708SF females were weighed and then placed in pens on the day of hatch (92 chicks/pen). At 25 D, 4 pens were infected with H. meleagridis in the cloaca, whereas 4 pens were control. At 5, 10, and 20 D after inoculation, 5 birds per pen (2 birds per pen at 20 D) were subjectively scored for blackhead disease. Birds were feed restricted based on BW and/or egg production. Individual BW were collected at 3, 5, 13, 15, 20, and 64 wk. Egg production was recorded at 24–63 wk. Egg quality was measured at 30, 34, 39, 42, and 56 wk and included shell and vitelline membrane strength, shell thickness, egg weight, and Haugh units. Hatchability was measured at 27, 37, and 60 wk and fertility at 27 and 37 wk. Treatment effects were determined by JMP Pro 14 using GLM with means separated using the Student t test (P ≤ 0.05). Cecal lesions were apparent on 5, 10, and 20 D and liver lesions on 10 and 20 D for the infected birds. The control had no histomoniasis lesions. Flock uniformity differed on wk 13 and 20 (P = 0.04; 0.04). Infected birds weighed less at 64 wk (P = 0.002). The onset of lay was not delayed. Infected birds produced more eggs during 1 period (P = 0.02). The infected birds produced heavier eggs at 30 wk (P = 0.04), eggs with a stronger and thicker shell at 42 wk (P = 0.05, 0.03), and eggs with a stronger vitelline membrane at 56 wk (P = 0.049). Hatchability and fertility did not differ (P > 0.05). H. meleagridis was observed in the infected birds' cecal samples at trial termination. This study indicates early infection with H. meleagridis has limited effects on pullet egg production and quality.}, journal={Poultry Science}, author={Chadwick, Elle and Malheiros, Ramon and Oviedo, Edgar and Noboa, Hernan Alejandro Cordova and Ospina, Gustavo Adolfo Quintana and Wisaquillo, Maria Camila Alfaro and Sigmon, Christina and Beckstead, Robert}, year={2020}, month={Sep} }
 @article{sigmon_malheiros_anderson_payne_beckstead_2019, title={Blackhead Disease: Recovery of Layer Flock After Disease Challenge}, volume={28}, ISSN={1056-6171}, url={http://dx.doi.org/10.3382/japr/pfz029}, DOI={10.3382/japr/pfz029}, abstractNote={SUMMARY Blackhead disease, caused by the protozoan Histomonas meleagridis, is commonly found in layer pullets raised on the floor. We examined the effects of blackhead disease during the pullet-rearing period and on subsequent productivity during the first 8 wk of the laying cycle. Treatments were (1) uninfected controls and (2) H. meleagridis -infected pullets, with 4 replicate pens/treatment, 32 pullets/pen (Hy-LineW-36). Pullets in the challenge treatment were infected with H. meleagridis on day 18. Four birds/pen were necropsied on days 23 and 28 for lesion scores and day 176 for detection of H. meleagridis. Hens were moved to individual layer cages on day 120 and observed daily for feed consumption, date of first lay and egg production parameters. Pullets were positive for signs of blackhead disease in 83%–90% of infected birds necropsied on days 23 and 28, with average cecal lesion scores of 2.5 and 2.9. No liver lesions were observed. On day 176, 40% of infected birds were positive for H. meleagridis in the ceca. During the laying cycle, there were no significant differences (P ≤ 0.05) between treatments in terms of date of first lay, hen-day egg production, egg weight, feed conversion, egg mass/hen, or other reproduction measurements. These results showed that while there was no long-term effect of blackhead infection on layer productivity under laboratory conditions, H. meleagridis persisted in the flock, providing a reservoir for infection.}, number={3}, journal={Journal of Applied Poultry Research}, publisher={Elsevier BV}, author={Sigmon, C.S. and Malheiros, R.D. and Anderson, K.E. and Payne, J.A. and Beckstead, R.B.}, year={2019}, month={Sep}, pages={755–760} }
 @article{smith_northcutt_sigmon_parisi_2015, title={Effect of Sex, Bird Size and Marination on Duck Breast Meat Quality}, volume={14}, ISSN={1682-8356}, url={http://dx.doi.org/10.3923/ijps.2015.191.195}, DOI={10.3923/ijps.2015.191.195}, number={4}, journal={International Journal of Poultry Science}, publisher={Science Alert}, author={Smith, D.P. and Northcutt, J.K. and Sigmon, C.S. and Parisi, M.A.}, year={2015}, month={Apr}, pages={191–195} }