Progress 05/01/15 to 04/30/18
Outputs
Target Audience:Broiler and other poultry industry, Broiler and other poultry growers, meat industry, feed industry, national and international researchers in poultry and animal nutrition and meat science, governmental agencies related to poultry and animal production, students in poultry, animal and meat sciences, and consumers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This project has provided graduate students and post-doctorates in our labs with comprehensive hands-on experience in broiler production, chicken processing, collections of blood and muscle tissue samples, the sample handling, and basic and advanced analytical techniques that are essential in studying in poultry and meat science areas. They have been trained to acquire proper animal and sample handling and sample preparation techniques to minimize changes in the blood and muscle samples during storage and sample preparation. They have been also trained to acquire the knowledge and techniques of biochemical and physicochemical analyses to determine heat stress and oxidative stress indicators in blood and muscle samples, parameters of postmortem glycolysis, and parameters of meat quality. The sample handling and advanced analytical skill sets acquired through the training will be of great assets for the student's future research career in the animal and meat science area. They have also had opportunities to present their research results in professional conference for personal development. In addition, more than 10 undergraduate and graduate student volunteers had hands-on experience in chicken processing to learn processing steps and what is important in each step in relation to food safety and meat quality. How have the results been disseminated to communities of interest?Three abstracts were presented at local, national, and international professional conferences such as American Society of Animal Science (ASAS) annual meeting, US-Korea Reserach Conference, and UMES regional research symposiums in order to share the results of the project with targeted audience and the public. Master's thesis was also published to disseminate the information generated by this project. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Chickens are sensitive to heat stress because of their narrow critical temperature range for survival and growth (16-26°C for finishing broilers). Temperatures over 30 °C are generally considered heat stress conditions for chickens. Heat stress causes high mortality, lower growth performance and muscle growth, and increased susceptibility to diseases. Especially, heat stress during the finishing period is considered a primary cause of quality deterioration, such as discoloration and poor water holding capacity, in chicken breast meat. It is estimated that heat stress causes a loss of over $200 million annually for the U.S. broiler industry alone. Hence, many intervention technologies against heat stress have been studied for chicken production. Early heat conditioning (EHC) is one of the promising technologies to enhance chick's temperature adaptation ability while developing by exposing 3- to 7-day-oild chicks to expected high temperatures (36-38°C) for up to 24 hours to improve heat tolerance of chickens at market ages. The results of this project indicated that EHC can prevent or mitigate heat stress effects on growth performance of birds and oxidative stability of chicken breast meat, suggesting the potential of EHC as an effective intervention strategy against heat stress for chicken production and meat quality. The objective I of the project was to determine the effects of EHC at different ages on the heat stress indicators and metabolic parameters in live birds and broiler breast muscle. A total of 180 broiler male chicks (Ross 708; 1-day-old) in 30 pens were randomly allotted to 5 treatments (6 pens/treatment) and raised for 42 days: 3 EHC groups (3, 5, and 7-day-old chicks exposed to EHC at 35 °C for 6 h), positive (no EHC) and negative (EHC for 5-day-old chicks). All treatment groups, except for negative control, were exposed to chronic heat challenge during the final week, using cyclic temperature control (CTC) at 32/25°C (12 h cycle) which simulates temperature changes in day/night. Growth performance (feed intake, weight gain, feed conversion ratio (FCR)) was determined at a two-week interval during broiler production. Plasma was collected right after the heat challenge and analyzed for heat stress indicators (corticosterone and triiodothyronine) and oxidative stress markers (oxidation of DNA, protein, and lipids, total ROS (reactive oxygen species) content, and total antioxidant capacity). At Day 43, breast muscle was collected at 0.25, 2, and 24 h postmortem. They were quickly frozen in liquid N2, stored in a -80 °C freezer, and then analyzed for heat stress indicators (heat shock protein-70 and protein oxidation) and parameters of postmortem glycolysis (pH, contents of glycogen, lactate, ATP, ADP, and AMP, AMP-activated protein kinase activity). No significant differences in the most parameters analyzed in plasma and muscle were observed among treatments. These results could be due to unexpected incidences of Woody Breast/White Striping. We found that over 65% of the chicken breast in all the treatment groups were in severe to mild Woody Breast/White Striping. Woody Breast is currently the most concerned quality defect of chicken breast, featured with a bulged, hard structure with or without hemorrhage, and often accompanied by White Striping. Recent studies have reported that up to 78% of chicken breast showed Woody Breast, and estimated an annual loss of over $200 million in the U.S. The mechanism causing Woody Breast has not been clearly identified. It was suggested that Woody Breast develops as early as 18 days in age. Therefore, the metabolic changes causing Woody Breast could overwhelm any changes induced by EHC and heat stress. Our observation in this study suggested that EHC and heat stress may not be related to the incidence of Woody Breast/White Striping. Despite the situation caused by Woody Breast/White Striping, we could identify that the EHC group at Day 3 showed tendencies to more effectively mitigate the heat stress effects on feed consumption and protein oxidation in muscle, compared to those at Day 5 and 7. Hence, we selected the 3 days of age as the best age for EHC. The objective II was to determine the effectiveness of EHC against the heat stress-induced quality deteriorations in broiler breast meat under different heat challenges (chronic vs acute heat stress). Chronic heat stress (C-HS) represented for high environmental temperature and acute heat stress (A-HS) for heat waves. We were informed by a poultry geneticist that Woody Breast has been frequently observed in the ROSS strain used for Objective I. Thus, we used a different broiler strain (Cobb 500) for Objective II, and found that the incidence of Woody Breast was minimal. This result suggested that its incidence could be mainly affected by genetic factors such as broiler strains, rather than environmental factors such as heat stress. A total of 180broiler male chicks (1-day-old; Cobb 500) in 30 pens were randomly allotted to 5 treatment groups and raised for 42 days: 2 groups were exposed to EHC (at 37 °C for 12h) at 3 days of age, then subjected to C-HS (12h-CTC at 32/25 °C) during the final week and A-HS (at 36 °C for 2h) at Day 41, respectively. Two no-EHC groups were exposed to both heat challenges as negative controls, respectively. The control was without EHC and HS. Growth performance data and plasma and muscle samples were collected and analyzed as described in Objective I. Parameters for meat quality, including color, drip loss, water holding capacity, cooking yield, marinate uptake, protein solubility, protein and lipid oxidation, total antioxidant capacity (TAC) and texture properties, were determined using breast meat collected at 24 h postmortem. Both C-HS and A-HS significantly reduced body weight gain and feed consumption during the final week and overall production period (6 wks), compared to the Control (p<0.05). However, only C-HS significantly increased FCR compared to the Control and A-HS groups (p<0.05), probably due to the longer duration of C-HS. The losses of growth performance caused by both heat stress were effectively prevented by EHC (p<0.05). EHC and/or HS did not affect heat stress and oxidative stress indicators in plasma and postmortem glycolysis parameters in muscle. On the other hand, both HS significantly increased protein oxidation and decreased TAC in chicken breast meat compared to the Control (p<0.05), and the extents of their changes were more severe by A-HS than by C-HS (p<0.05). The adverse effects of A-HS on protein oxidation and TAC was considerably mitigated, but not prevented, by EHC (p<0.05). However, other meat quality parameters were not affected by EHC and/or HS. These results suggested that, under more severe heat stress conditions, the oxidative stability and muscle proteins in breast meat could be further damaged to the level where the quality defects can be detected, and that EHC could effectively mitigate it. In conclusion, the results of this project showed that both types of heat stress (chronic and acute heat stress) adversely affected growth performance of birds and oxidative stability in chicken breast meat, and acute heat stress had the more severe effects than chronic heat stress. This suggests that the intensity of heat stress could be the more determining factor for its impacts on chicken production and meat quality than its duration. The results also showed that EHC prevented adverse effects of both heat stress on growth performance and effectively alleviated the acute heat stress-induced deterioration of the oxidative stability in chicken breast meat. Therefore, the results of this project suggested that EHC has the potential as an effective intervention technique for the prevention or mitigation of the heat stress effects against the broiler production and quality of chicken breast meat.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Punchihewage Don, A. J., Attuquayefio, W., Oh, S., Feng, Xi, Ahn, D. U., and Min. B. R. 2018. Effects of early heat conditioning on heat stress-induced changes in growth performance, oxidative stress in plasma, and quality parameters in broiler breast meat. 2018 American Society of Animal Science Annual Meeting. July 8-12, 2018.Vancouver, Canada.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Punchihewage Don, A. J., Attuquayefio, W., Oh, S., and Min, B. R. 2018. Effects of early heat conditioning on chicken production and breast meat quality. 2018 US Korean Conference. August 1-4, 2018. Queens, NY.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Punchihewage Don, A. J., Attuquayefio, W., and Min, B. 2018. Effects of Early Heat Conditioning at Different Ages on Heat Stress Indicators and Metabolic and Quality Parameters in Broiler Breast Meat. 9th Annual UMES Regional Research Symposium 2018. April 17, 2018. Princess Anne, MD.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2018
Citation:
Punchihewage Don, A. J. 2018. Effects of early heat conditioning (EHC) on stress responses and breast meat quality of broilers raised under different heat stress conditions. MS Thesis. University of Maryland Eastern Shore, Princess Anne, MD.
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Progress 05/01/16 to 04/30/17
Outputs
Target Audience:Broiler and other poultry industry, Broiler and other poultry growers, meat industry, feed industry, national and international researchers in poultry and animal nutrition and meat science, governmental agencies related to poultry and animal production, students in poultry, animal and meat sciences, and consumers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The project has provided graduate students with hands-on experience in bird handing, collect blood samples, slaughtering process, collection of muscle tissue, handling of blood and muscle tissue samples, and basic and advanced analytical techniques which are essential in studying in poultry and meat science areas. They have been trained for proper animal and sample handling and sample preparation techniques to minimize changes in the blood and muscle samples during storage and sample preparation. They were also trained for knowledge and techniques to perform advanced analyses to determine biochemical parameters related to postmortem changes and meat quality and oxidative stress indicators in blood and muscle samples, and meat quality. The sample handling and advanced analytical skill sets acquired through the training will be of great assets for the student's future research career in the animal and meat science area. How have the results been disseminated to communities of interest?We discussed our findings in this report period with the local broiler industry. What do you plan to do during the next reporting period to accomplish the goals?Partial samples analyses have been done for Objective I. The analyses for heat stress hormones and oxidative stress indicators in plasma and heat stress indicators and parameters of postmortem glycolysis in breast muscle will be performed to accomplish Objective I. According to our observation and the personal communication with an expert, woody breast can be developed in ROSS708 at a high rate. Therefore, we will use a different commercial strain for Objective II in order to avoid high incidence of woody breast. The broiler production and sample analyses for Objective II will be conducted. The results will be presented in local, national and international professional conferences and the article will be prepared for submission to peer-reviewed journals.
Impacts
What was accomplished under these goals?
The objective of the project accomplished in this period was to determine the effects of early heat conditioning (EHC) at different ages on the heat stress indicators and metabolic parameters in live birds and broiler breast muscle (Objective 1). A total of 180 broiler male chicks (ROSS708, 1-day-old) were allotted to 30 pens (6 birds/pen) which were then randomly assigned to 5 treatment groups (6 pens/treatment): A) EHC at Day 5 and no heat challenge (Negative control), B) No EHC and heat challenge during the final week (Positive control), C) EHC at Day 3 and heat challenge during the final week, D) EHC at Day 5 and heat challenge during the final week, and E) EHC at Day 7 and heat challenge during the final week. For EHC, 3-, 5-, or 7-day-old chicks were conditioned at 33-35 °C for 6 h. During the final week (6th week), chickens were exposed to chronic heat challenge using cyclic temperature control (CTC) at 32/25°C (12 h cycle), which simulated temperature changes in day/night (32/25 °C, respectively). Body and feed weights were recorded at a two-week interval to determine growth performance (feed intake, weight gain, and feed conversion ratio). Plasma samples were separated by centrifugation from blood collected at one day before (Day 35) and the last day (Day 42) of heat challenge, and stored in a -80 °C freezer. Breast muscle samples were collected after slaughtering of broilers on Day 43 a) immediately after carcass washing (at 0.25 h), b) Immediately after immersion chilling (at 2 h), and c) after 24 h storage at 4 °C (at 24 h). They were quickly frozen in liquid nitrogen, powdered, and stored in a -80 °C freezer. Growth performance, including feed intake, weight gain, and feed conversion ratio, was not affected by EHC at different ages and/or the heat challenge during the final week. Sample analyses for heat stress hormones and oxidative indicators in plasma and heat stress indicators and parameters of postmortem glycolysis in breast muscle are being conducted. Partial results from the sample analyses for postmortem glycolysis parameters, including pH, concentrations of ATP, ADP, and AMP, glycogen potential, muscle protein oxidation, and color, did not show any difference among the treatments. These results could be due to high incidences of woody breast. We found that over 65% of chicken breasts in all the treatment groups, regardless of EHC and/or chronic heat challenge, were in severe and mild woody breast conditions with white striping. Woody breast and white striping has been recently identified as a major quality issue for chicken breast. Our observation in this study indicated that the incidence of woody breast may be not be related to environmental stress factors such as heat stress.
Publications
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Progress 05/01/15 to 04/30/16
Outputs
Target Audience:Broiler and other poultry industry, broiler and other poultry growers, meat industry, feed industry, national and international researchers in poultry and animal nutrition and meat science, governmental agencies related to poultry and animal production, students in poultry, animal and meat sciences, and consumers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This project has provided graduate students in our labs with hands-on experience in handing of birds, bleeding of birds, slaughtering process, collection of muscle tissue, handling of blood and muscle tissue samples, and basic and advanced analytical techniques that are essential in studying in poultry and meat science areas. They have been trained to acquire proper animal and sample handling and sample preparation techniques to minimize changes in the blood and muscle samples during storage and sample preparation. They were also trained to acquire knowledge and techniques to perform advanced analyses to determine biochemical parameters related to postmortem changes and meat quality and oxidative stress indicators in blood and muscle samples, and meat quality. The sample handling and advanced analytical skill sets acquired through the training will be of great assets for the student's future research career in the animal and meat science area. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?The analyses for heat stress hormones and oxidative stress indicators in plasma and heat stress indicators and parameters of postmortem glycolysis in breast muscle will be performed to accomplish the objective I. The broiler production and sample analyses for Objective II will be conducted. The results will be presented in local, national and international professional conferences and the article will be prepared for submission to peer-reviewed journals.
Impacts
What was accomplished under these goals?
Pilot studies requested by the IACUC were conducted to adjust conditions for acute heat stress challenge. The main objective of the pilot studies was to make sure that the stress conditions are severe, but not too excessive to kill the birds. Based on the results of the pilot studies, a new set of protocols, including adjusted temperature and duration under the stress conditions (36 °C for 2 hours), and the number of birds used (180 birds per study), have been developed and approved by the IACUC. Male broiler chicks were treated with early heat conditioning at different ages (3, 5, and 7 day-old) and raised on a corn-soybean basal diet with ad libitum access to feed and water. Body and feed weights were recorded at a two-week interval to determine growth performance (feed intake, weight gain, and feed efficiency). Broilers were exposed to chronic heat challenge using cyclic temperature control (CTC) at 32/25 °C for the last one week, which simulates temperature changes in day/night - 32/25 °C, respectively. Blood samples were collected at one day before (at Day 35) and the last day (at Day 42) of the heat challenge. Plasma was separated and stored in a -80 °C freezer for further analyses. At Day 43, the broilers were slaughtered and muscle samples were collected at 0.25, 2, and 24 hour of postmortem, quickly frozen in liquid nitrogen, and stored in a -80 °C freezer for further analyses. Sample analyses for heat stress hormones and oxidative stress indicators in plasma and heat stress indicators and parameters of postmortem glycolysis in breast muscle are under way.
Publications
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