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Since about 1950, numerous examples of extreme climate events have been recorded. These include not only the increase in temperature which has caused frequent and intense heat waves, melting ice caps, and high sea level, but also an extreme low winter temperature along with higher precipitation in different regions in the world. Further changes in the climate sys-tem are predicted to increase over the course of the 21st century.
NUTRITIONAL SCIENCES ISSN 2377-8350 http://dx.doi.org/10.17140/AFTNSOJ-2-124 Open Journal Short A New Insight into Cold Stress In Poultry Communication Production * *Corresponding author Sami Dridi, PhD 1 1 2 Phuong H. Nguyen, MS ; Elizabeth Greene, PhD ; Annie Donoghue, PhD ; Geraldine Associate Professor 2 1 1* Huff, PhD ; F. Dustan Clark, PhD ; Sami Dridi, PhD Center of Excellence for Poultry Science University of Arkansas 1260 W Maple Street, Fayetteville 1Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA AR 72701, USA Tel. (479)-575-2583 2 USDA, Agricultural Research Service, Poultry Production and Product Safety Research Unit, Fax: (479)-575-7139 E-mail: dridi@uark.edu Fayetteville, AR 72701, USA Volume 2 : Issue 1 Article Ref. #: 1000AFTNSOJ2124 Since about 1950, numerous examples of extreme climate events have been recorded. These include not only the increase in temperature which has caused frequent and intense heat Article History waves, melting ice caps, and high sea level, but also an extreme low winter temperature along th with higher precipitation in different regions in the world. Further changes in the climate sys- Received: March 17 , 2016 st 1 st tem are predicted to increase over the course of the 21st century.1 Since growing animals are Accepted: March 31 , 2016 st vulnerable to extreme temperature, climate changes become an important critical constraint Published: April 1 , 2016 1,2 to several species in the world.1,2 In poultry production, while heat stress has been a rising concern for producers and scientists, cold stress has also caused economic loss worldwide. In Citation China, winter conditions and low temperature caused almost 20 million poultry deaths and an Nguyen PH, Greene E, Donoghue economic loss of 100 million (Chinese currency) in 2008. Early research in poultry exposed to A, Huff G, Clark FD, Dridi S. A new 4-6 insight into cold stress in poul- acute cold stress has shown a clear suppression in development, survival and egg production.4-6 try production. Adv Food Technol Nutr Sci Open J. 2016; 2(1): 1-2.
At the molecular level, an acute hypothermal condition significantly up-regulated doi: 10.17140/AFTNSOJ-2-124 7 ° gene expression of hepatic leptin and muscle UCP in 5-wk-old broilers. Exposure at 4 C for 24 hours resulted in changes in some genes involved in lipid metabolism in broilers pituitary. This suggests that cold stress can affect lipid metabolism.3 At younger age (7-14 days old), al- ° though a chronic cold stress (20 °C) did not affect body weights and feed intake, it significantly increased chick body heat production and avUCP gene expression in the leg muscle.8 Birds exposed to cold stress had severely injured liver and increased gene expression of AMPKα– PPARα pathway.9 Moreover, there is clear evidence that cold stress affects thyroid hormones 8,10 (T3 and T4) which play a key role in energy expenditure and body temperature homeostasis.8,10 Yet, the effect of cold exposure on growth performance is still controversial. Indeed, Baar- 11 ° ° endse and colleagues11 observed that moderate cold exposure (28 °C, reducing 1 °C every day in five-day period) during the early post-hatching period caused long-term negative effects on chicken growth performance. However, Shinder and colleagues reported that acute cold expo- 10,12 sure at late embyogenesis improved growth performance. These discrepancies might be due to several factors including experimental conditions (environmental temperature, age, chicken strain, and/or exposure duration). We recently investigated the effect of Chronic Mild Cold Conditioning (CMCC) and its underlying molecular mechanisms on growth performances in broilers. Our data show that CMCC improved the growth performance of chicks during the first week post-hatch and their later lives in terms of body weight gain and Feed Conversion Ratio (FCR).13 Plasma cholesterol and creatine kinase (CK) levels increased indicating a potential role of CK in maintaining high ATP turnover in a hypothermal condition.14 Hypothalamic orex- igenic neuropeptide Y (NPY) and anorexigenic cocaine and amphetamine regulated transcript Copyright (CART) gene expression were significantly down-regulated in the brain of cold group which ©2016 Dridi S. This is an open ac- may explain the reduction of feed intake in CMCC compared to the control group. CMCC also cess article distributed under the Creative Commons Attribution 4.0 modulated the hepatic expression of lipogenic genes, which implies the inhibition of fatty acid International License (CC BY 4.0), synthesis in cold stress chicks.13 Moreover, CMCC enhanced muscle fatty acid β-oxidation which permits unrestricted use, through affecting the gene and protein expression of carnitine palmitoyl transferase-1 (CPT-1) distribution, and reproduction in 16,17 and phosphorylated mTOR.
any medium, provided the original work is properly cited.
NUTRITIONAL SCIENCES ISSN 2377-8350 http://dx.doi.org/10.17140/AFTNSOJ-2-124 Open Journal In summary, the CMCC used in our study could im- 9. Zhang ZW, Bi MY, Yao HD, Fu J, Li S, Xu SW. Effect of prove later growth performance of young chicks (body weight Cold Stress on Expression of AMPKα-PPARα Pathway and gain and FCR). This is new evidence that gives us a broader Inflammation Genes. Avian Dis. 2014; 58(3): 415-426. doi: view of how young birds can adapt to and prepare for changes in 10.1637/10763-010814-Reg.1 their environment. In addition, gene expression analyses provide insight into the roles of the AMPK-mTOR pathway in cold accli- 10. Shahir MH, Dilmagani S, Tzschentke B. Early-age cold con- mation; thus further studies are needed to understand the regula- ditioning of broilers: effects of timing and temperature. Br Poult tion of these genes for better management via genetic selection Sci. 2012; 53(4): 538-544. doi: 10.1080/00071668.2012.719604 and/or nutritional strategies to improve cold tolerance and feed efficiency.
11. Baarendse PJ, Kemp B, Van Den Brand H. Early-age housing temperature affects subsequent broiler chick- CONFLICTS OF INTEREST: None.
en performance. Br Poult Sci. 2006; 47(2): 125-130. doi: 10.1080/00071660600610575