@article{cutchin_wineland_christensen_davis_mann_2009, title={Embryonic development when eggs are turned different angles during incubation}, volume={18}, ISSN={["1537-0437"]}, DOI={10.3382/japr.2008-00079}, abstractNote={SUMMARY Not turning eggs during incubation or turning at a reduced angle could potentially reduce the incidence of hot spots in machines, thereby lessening the chance of embryonic mortality and decreased hatchling quality caused by overheating. Not turning eggs can also allow more eggs to be placed in an incubator by designing the machine with trays closer together. However, eggs that are not turned during incubation exhibit a higher frequency of embryonic developmental deficiencies and a reduced hatch compared with turned eggs. An experiment was conducted to determine the effects of a reduced turning angle on embryonic and extraembryonic development. Turning eggs 15° caused an increase in embryonic mortality from d 11 to 16 and d 17 to 21 and an overall decrease in hatch when compared with turning eggs 45°. There was no difference in area vasculosa at d 3 but there was a reduced amount of subembryonic fluid at d 6. Overall, it was determined that a reduced turning angle decreases the hatch of fertile eggs.}, number={3}, journal={JOURNAL OF APPLIED POULTRY RESEARCH}, author={Cutchin, H. R. and Wineland, M. J. and Christensen, V. L. and Davis, S. and Mann, K. M.}, year={2009}, pages={447–451} }
 @article{oviedo-rondon_wineland_funderburk_small_cutchin_mann_2009, title={Incubation conditions affect leg health in large, high-yield broilers}, volume={18}, ISSN={1056-6171 1537-0437}, url={http://dx.doi.org/10.3382/japr.2008-00127}, DOI={10.3382/japr.2008-00127}, abstractNote={SUMMARY Leg problems are observed in every flock of broilers, and they occur more frequently in heavy, fast-growing broilers. Factors such as genetics, growth rate, stressors, nutrition, and lighting programs can contribute to and change the prevalence of these problems in broiler production. Our previous research has shown that elevated incubation temperatures and oxygen concentrations below 21% during the last days of embryo development can negatively affect thyroid hormones, relative asymmetry and normal development of leg bones, and development of other tissues and organs that influence leg health and locomotion in broilers. This project evaluated the effects of incubation profiles on leg health of high-yielding broilers at 8 wk of age under commercial conditions. Eggs from the same breeder flocks were incubated in either single-stage or multistage machines. Hatchlings were placed in paired houses on the same farms, and at 56 d of age, leg health was evaluated. There was variability among farms and hatches: leg problems such as footpad dermatitis were more closely related to farm conditions, whereas valgus and especially hock burns were influenced by incubation conditions within each farm. However, this fieldwork demonstrated that proper incubation conditions improve broiler performance, especially in females (1.2%); may reduce leg health problems such as crooked toes; and may even improve locomotion.}, number={3}, journal={The Journal of Applied Poultry Research}, publisher={Oxford University Press (OUP)}, author={Oviedo-Rondon, E. O. and Wineland, M. J. and Funderburk, S. and Small, J. and Cutchin, H. and Mann, M.}, year={2009}, month={Jan}, pages={640–646} }
 @article{oviedo-rondon_small_wineland_christensen_mozdziak_koci_funderburk_ort_mann_2008, title={Broiler embryo bone development is influenced by incubator temperature, oxygen concentration and eggshell conductance at the plateau stage in oxygen consumption}, volume={49}, ISSN={["1466-1799"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-57849128060&partnerID=MN8TOARS}, DOI={10.1080/00071660802433149}, abstractNote={1. Four experiments were conducted to evaluate the effects of temperature (TEM) and oxygen (O2) concentrations during the last 4 d of incubation on bone development. Fertile eggs from two strains were obtained that either exhibited Low or High eggshell conductance (G). 1The mention of trade names in this publication does not imply endorsement of the products mentioned nor criticism of similar products not mentioned. 2. Four experimental cabinets provided either four TEM (36, 37, 38 or 39°C) or four O2 concentrations (17, 19, 21 or 23% O2). Data were analysed as a 2 × 2 factorial design. In the fourth experiment, two temperatures (36 and 39°C), two O2 concentrations (17 and 23%) and the same Low and High G strains were evaluated in a 2 × 2 × 2 factorial design. 3. Body weights (BW) and residual yolks were obtained, both legs were dissected. Femur, tibia and shank weights, length and thickness were recorded. Relative asymmetry (RA) of each leg section was calculated. 4. The results indicated that elevated TEM during incubation increased RA between the two legs, mainly in the Low G strain. Chickens at the lowest O2 concentrations had lighter and shorter tibias, lighter shanks, and increased RA of femur length compared to chickens in the 23% O2. In the fourth experiment no interactions were observed between O2 and TEM. High TEM depressed BW of Low G broilers, but no significant effect of treatments was observed on BW of High G broilers. Nevertheless, the high TEM or low O2 independently caused reduced femur and tibia weights and length, shank length and thickness, and both low O2 and high TEM together increased RA in shank weight. 5. These results suggest that late incubation conditions affect long bone development in broilers.}, number={6}, journal={BRITISH POULTRY SCIENCE}, author={Oviedo-Rondon, E. O. and Small, J. and Wineland, M. J. and Christensen, V. L. and Mozdziak, P. S. and Koci, M. D. and Funderburk, S. V. L. and Ort, D. T. and Mann, K. M.}, year={2008}, pages={666–676} }
 @article{oviedo-rondon_small_wineland_christensen_grimes_funderburk_ort_mann_2008, title={Effects of incubator temperature and oxygen concentration during the plateau stage of oxygen consumption on turkey embryo long bone development}, volume={87}, ISSN={["1525-3171"]}, DOI={10.3382/ps.2007-00470}, abstractNote={Temperature (TEM) and O(2) concentrations during the plateau stage of oxygen consumption are known to affect yolk utilization, tissue development, and thyroid metabolism in turkey embryos. Three experiments were conducted to evaluate these incubation effects on long bone development. Fertile eggs of Nicholas turkeys were used. In each trial, standard incubation conditions were used to 24 d, when the eggs containing viable embryos were randomly divided into 4 groups. Four experimental cabinets provided 4 TEM (36, 37, 38, or 39 degrees C) or 4 O(2) concentrations (17, 19, 21, or 23% O(2)). In the third experiment, 2 temperatures (36 and 39 degrees C) and 2 O(2) concentrations (17 and 23%) were evaluated in a 2 x 2 factorial design. Body and residual yolk weights were obtained. Both legs were dissected, and shanks, femur, and tibia weights, length, and thickness were recorded. Relative asymmetry of each leg section was calculated. Chondrocyte density was evaluated in slides stained with hematoxylin and eosin. Immunofluorescence was used to evaluate the presence of collagen type X and transforming growth factor beta. Hot TEM caused reduction of tibia weights and increase of shank weight when compared with cool TEM. The lengths of femur, tibia, and shanks were reduced by 39 degrees C. The relative asymmetry of leg weights were increased at 38 and 39 degrees C. Poult body and part weights were not affected by O(2) concentrations, but poults on 23% O(2) had bigger shanks and heavier tibias than the ones on 17% O(2). High TEM depressed the fluorescence of collagen type X and transforming growth factor beta. The O(2) concentrations did not consistently affect the immunofluorescence of these proteins. The chondrocyte density was affected by TEM and O(2) in resting and hypertrophic zones. In the third experiment, high TEM depressed BW, leg muscle weights, and shank length. Low O(2) reduced tibia and shanks as a proportion of the whole body. We concluded that incubation conditions affect long bone development in turkeys.}, number={8}, journal={POULTRY SCIENCE}, author={Oviedo-Rondon, E. O. and Small, J. and Wineland, M. J. and Christensen, V. L. and Grimes, J. L. and Funderburk, S. V. L. and Ort, D. T. and Mann, K. M.}, year={2008}, month={Aug}, pages={1484–1492} }
 @article{wineland_christensen_yildrum_fairchild_mann_ort_2006, title={Incubator temperature and oxygen concentration at the plateau stage in oxygen consumption affects intestinal maturation of broiler chicks}, volume={5}, ISBN={1682-8356}, DOI={10.3923/ijps.2006.229.240}, abstractNote={Incubator temperature and oxygen concentrations were tested as factors determining the intestinal maturation of two lines of broiler chickens. One line was a Low G line selected because its eggs display low eggshell conductance. The second line was a High G line that grew at a reduced rate and its eggs show high eggshell conductance values. All eggs were incubated normally until the 18 day of development or the th beginning of the plateau stage in oxygen consumption. At that time the eggs were divided randomly and placed into experimental cabinets operating at 36, 37 38 or 39oC in experiment 1 or with 17, 19, 21 or 23% oxygen in experiment 2. In experiment 3, the best and worst conditions observed in experiments 1 and 2 were combined in a factorial arrangement. Body weight and intestinal maturation were measured by assaying for maltase and alkaline phosphatase activities in intestinal tissues. Increasing temperatures suppressed intestinal maturation whereas increasing oxygen concentrations enhanced intestinal maturation. When examined together in a factorial arrangement, it was clear that the effects of temperature and oxygen on the embryos were independent because they did not interact. The effects of temperature and oxygen were greater on Low G broiler embryos than they were on High G type embryos. It is concluded that incubator temperatures greater than 37o C, and oxygen concentrations less than 21% are detrimental to intestinal maturation in broiler chicks.}, number={3}, journal={International Journal of Poultry Science}, author={Wineland, M. W. and Christensen, V. L. and Yildrum, I. and Fairchild, B. D. and Mann, K. M. and Ort, D. T.}, year={2006}, pages={229} }
 @article{christensen_wineland_ort_mann_2005, title={Eggshell conductance and incubator ventilation as factors in embryo survival and poult quality}, volume={4}, ISBN={1682-8356}, DOI={10.3923/ijps.2005.818.826}, abstractNote={Eggshell conductance (G) and incubator ventilation (VENT) were hypothesized to affect embryo viability and growth of poults following hatching. Nearly 6,000 eggs were weighed on the day of oviposition to determine eggs of like weight but of different G. From the 6,000 eggs, 4,000 were selected that were within 2 standard deviations of the mean. The eggs were randomly divided equally between two incubator cabinets. One cabinet operated with a closed VENT and a second operated with it open. At the completion of the 24 day of development, all eggs were weighed a second time to determine eggshell G. Three groups were formed at that time exhibiting high (Hi), average (Avg) or low (Low) G. The eggs within each group were placed into hatching trays of 100 eggs each and placed into he same incubation cabinet for hatching. Weights were recorded for cardiac, hepatic and intestinal tissues, and blood was collected from each treatment. The tissues were subsequently assayed for energy substrates. Embryo viability was noted and growth was observed up to 6 wk of age. More embryos in eggs of Hi or Avg G survived than did those in Low G eggs, but neonates at 6 wk from Hi G eggs weighed less than those from Avg or Low G eggs. Low G embryos had reduced heart, liver and intestinal weight and function. Embryo thyroid hormone concentrations were elevated in Hi G eggs but suppressed by Low G and Closed VENT. Thus, in the developmental process of the embryonic turkey, G may determine energy balance and maturity of each hatchling and may affect its survival and growth rates following hatching.}, number={11}, journal={International Journal of Poultry Science}, author={Christensen, V. L. and Wineland, M. J. and Ort, D. T. and Mann, K. M.}, year={2005}, pages={818} }
 @article{christensen_wineland_yildirum_fairchild_ort_mann_2005, title={Incubator temperature and oxygen concentrations during the plateau stage in oxygen uptake affect turkey embryo plasma T4 and T3 concentrations}, volume={4}, ISBN={1682-8356}, DOI={10.3923/ijps.2005.268.273}, abstractNote={Avian embryo thyroid responses to incubator temperature and oxygen concentrations during the plateau stage in oxygen consumption were measured. It was hypothesized that turkey embryo thyroid responds in a limited way at this critical time to environmental conditions to modulate basal metabolism. Turkey embryos were exposed to one of four incubator temperatures (36, 37, 38 or 39 C) beginning on the o 25 day of incubation at the onset of the plateau, a time when plasma thyroxine (T ) and triiodothyronine (T ) th 4 3 concentrations normally increase. Blood was collected and thyroid hormone concentrations were measured at pipping (27 day) and hatching (28 day). Elevated temperatures depressed T and T concentrations and th th 3 4 increased the T to T ratios. In a second experiment four oxygen concentrations (17, 19, 21 or 23% oxygen) 3 4 were provided to the embryos using identical procedures. The 21% treatment significantly reduced T and 3 T at pipping compared to all other treatments, but 23% oxygen increased plasma T and the T to T ratio 4 3 3 4 compared to all other treatments. The 17% oxygen treatment elevated T compared to all other treatments. 3 At hatching, 23% oxygen elevated T and T to T ratios compared to all other treatments. When temperature 3 3 4 and oxygen treatments were applied together in a factorial arrangement, temperature and oxygen affected T and T hormone concentrations independently but did not interact. Therefore, we conclude that 3 4 temperature and oxygen are independent stimuli of the avian embryonic thyroid gland during the plateau stage, and that incubator temperature and oxygen concentrations can modulate development of turke y embryos by changing plasma T and T concentrations. 3 4}, number={5}, journal={International Journal of Poultry Science}, author={Christensen, V. L. and Wineland, M. J. and Yildirum, I. and Fairchild, B. D. and Ort, D. T. and Mann, K. M.}, year={2005}, pages={268} }
 @article{christensen_wineland_yildirum_ort_mann_2004, title={Incubator temperature and oxygen concentration at the plateau stage affect cardiac health of turkey embryos}, volume={3}, ISBN={1680-5593}, number={2}, journal={Journal of Animal and Veterinary Advances}, author={Christensen, V. L. and Wineland, M. J. and Yildirum, I. and Ort, D. T. and Mann, K. M.}, year={2004}, pages={52} }
 @article{christensen_wineland_yildirum_ort_mann_2004, title={Incubator temperature and oxygen concentration at the plateau stage affects intestinal maturation of turkey embryos}, volume={3}, ISBN={1682-8356}, DOI={10.3923/ijps.2004.378.385}, abstractNote={The plateau stage in oxygen consumption of turkey embryos occurs at 25 and 26 days of incubation when many embryos die. The plateau stage creates hypoxia, hypercapnia and presents a paradox for growth and embryo metabolism. Prior to the plateau, vital tissues accumulate glycogen to ensur e embryonic survival through anaerobic metabolism during the plateau. Intestinal maturation at the plateau demands great amounts of energy. Therefore, the objective of the study was to define the temperature and oxygen concentrations at the plateau that affect intestinal maturation. Three experiments were conducted to test incubator conditions during the plateau stage and their affect on intestinal maturation. In Experiment 1, turkey embryos at the plateau stage were exposed to 36, 37, 38 or 39 C. In Experiment 2, embryos at the o plateau stage were exposed to 17, 19, 21 or 23% oxygen concentrations, and in Experiment 3, the extreme levels of temperature and oxygen treatments were combined to test interaction effects on intestina l maturation. Elevating temperature depressed intestinal weight but not length. The elevated temperature also depressed intestinal maltase and alkaline phosphatase activities indicating inhibited function. Increasing oxygen had little effect on intestinal weight or length, but hypoxia increased maltase and decreased alkaline phosphatase activities in hatchlings. When examined in a factorial arrangement, temperature and oxygen displayed independent effects on growth and function and did not interact. Thus, incubator temperature greater than 37 C and oxygen concentrations less than 19% during the plateau stage delay intestinal o maturation.}, number={6}, journal={International Journal of Poultry Science}, author={Christensen, V. L. and Wineland, M. J. and Yildirum, I. and Ort, D. T. and Mann, K. M.}, year={2004}, pages={378} }