scholarly journals 209 Effects of heat stress on the intestinal tract of poultry

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 120-121
Author(s):  
Marcos Rostagnos

Abstract Stress is a biological adaptive response to restore homeostasis, and occurs in every animal production system, due to the multitude of stressors present in every farm. Heat stress is one of the most common environmental challenges to poultry worldwide. It has been demonstrated that heat stress negatively impacts the welfare and productivity of broilers and laying hens. However, our knowledge of basic mechanisms associated to the reported effects, as well as related to poultry behavior and welfare under heat stress conditions is in fact scarce. The adaptive response of poultry to a heat stress situation is complex and intricate in nature, and it includes effects on the intestinal tract. Intervention strategies to deal with heat stress conditions (e.g., management practices, feed additives, diet formulation, and others) have been the focus of most published studies. Nevertheless, effectiveness of most of the interventions has been variable or inconsistent. This review focuses on the scientific evidence available on the effects of the heat stress response on different facets of the intestinal tract of poultry, including its integrity, physiology, immunology and microbiology.

2020 ◽  
Vol 98 (4) ◽  
Author(s):  
Marcos H Rostagno

Abstract Stress is a biological adaptive response to restore homeostasis, and occurs in every animal production system, due to the multitude of stressors present in every farm. Heat stress is one of the most common environmental challenges to poultry worldwide. It has been extensively demonstrated that heat stress negatively impacts the health, welfare, and productivity of broilers and laying hens. However, basic mechanisms associated with the reported effects of heat stress are still not fully understood. The adaptive response of poultry to a heat stress situation is complex and intricate in nature, and it includes effects on the intestinal tract. This review offers an objective overview of the scientific evidence available on the effects of the heat stress response on different facets of the intestinal tract of poultry, including its physiology, integrity, immunology, and microbiota. Although a lot of knowledge has been generated, many gaps persist. The development of standardized models is crucial to be able to better compare and extrapolate results. By better understanding how the intestinal tract is affected in birds subjected to heat stress conditions, more targeted interventions can be developed and applied.


2018 ◽  
Author(s):  
Despina Samakovli ◽  
Tereza Tichá ◽  
Miroslav Ovečka ◽  
Ivan Luptovčiak ◽  
Veronika Zapletalová ◽  
...  

ABSTRACTStomatal ontogenesis is a key element of plant adaptation aiming to control photosynthetic efficiency and water management under fluctuating environments 1,2,3. Development of stomata is guided by endogenous and environmental cues and is tightly coupled to overall plant growth 1,2,3. YODA signaling pathway is essential to stomatal lineage specification4,5,6 since it regulates the activities of transcription factors such as SPEECHLESS (SPCH)7,8,9,10. Heat-shock proteins 90 (HSP90s) are evolutionarily conserved molecular chaperones implicated in a broad range of signalling pathways being integrated in interaction networks with client proteins11,12,13,14. Herein, based on genetic, molecular, biochemical, and cell biological evidence we report that heat-stress conditions affect phosphorylation and deactivation of SPCH and modulate stomatal density. We show that genetic and physical interactions between HSP90s and YODA control stomatal patterning, distribution and morphology. We provide solid evidence that HSP90s play a major role in transducing the heat-stress response since they act upstream and downstream of YODA signalling, regulate the activity and nucleocytoplasmic distribution of MAPKs, and the activation of SPCH. Thus, HSPs control the stomatal development both under normal temperature and acute heat-stress conditions. Our results demonstrate that HSP90s couple stomatal formation and patterning to environmental cues providing an adaptive mechanism of heat-stress tolerance response and stomatal formation in Arabidopsis.


2020 ◽  
Vol 70 (4) ◽  
pp. 453-470
Author(s):  
Petrović Slobodan ◽  
Maletić Milan ◽  
Lakić Nada ◽  
Aleksić Nevenka ◽  
Maletić Jelena ◽  
...  

AbstractThe aim of the current research was to assess the effects of the feed additive made of lyophilised melon juice (source of superoxide dismutase, SOD) and inactivated live Saccharomyces cerevisiae (strain R397) cells added to the feed via the product containing high levels of organically bound selenium (source of selenium-dependant glutathione peroxidase, Se-GPx) on the semen quality of bulls in heat stress conditions. The 15 bulls chosen for the experiment were assigned to three equal groups (control –group C; treated group M, given the source of SOD; and group A, treated with the source of Se-GPx). The research was conducted in summer. The activities of SOD and Se-GPx in seminal plasma were determined spectrophotometrically. Computer-assisted semen analysis was done to determine the sperm counts, motility and velocity. The temperature and humidity were recorded with a digital data logger.The average SOD activity in the control bulls was significantly lower than in M (p<0.001) and A (p<0.001), whilst the average activities in the treated groups did not differ significantly (p=0.784). Higher average SOD activity compared to the control in the treated groups showed that both feed additives increased the antioxidative capacity of the seminal fluid. The average GPx activity in the control was significantly lower than in groups A (p=0.001) and M (p=0.005), whilst the two treatments did not lead to significantly different results (p=0.701). The analysis of relations between the activity of each enzyme and sperm motility and progressive motility in each of the bulls failed to detect a significant correlation. The analysis of the relation between THI (temperature-humidity index) and the activity of the antioxidative enzymes revealed that the increase in THI coincided with the decrease in the SOD activity in the control group, but with its increase in the treated groups (p>0.05). In all of the three groups with the increase in THI there was an increase in GPx activity (p>0.05). It can be concluded that in all of the three groups of bulls there was an increase in the activity of both enzymes in the seminal plasma, but the increase was significantly lower in the control. Thus, the antioxidative capacity of the seminal plasma of untreated bulls was proven to be lower in comparison with those of the treated animals.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 33-34
Author(s):  
Madeline Rivera ◽  
Jordan Adams ◽  
Luis O Tedeschi

Abstract Contemporary nutritional research investigates the effects of diet formulation and feeding strategies on animal performance and global sustainability under different climates. Functional nutrition models have incorporated the effects of heat stress on net energy for maintenance requirements, dry matter intake (DMI), and milk production when accounting for animal and the environmental factors. It is commonly assumed that growing Bos indicus breeds receiving feedlot-type diets in tropical and subtropical regions have exhibited lower maintenance energy requirements than Bos taurus breeds. However, the ability to predict supplies of energy, protein, and minerals available to meet animal requirements depends on the accuracy and consistency of feed composition values obtained through digestibility trials and chemical analyses. Empirical observations indicate that feedstuffs grown in high temperatures affect cell wall lignification and metabolic activity rates, requiring special procedures for digestion trials. Similarly, physiological adaptation mechanisms in cattle in response to heat stress conditions include evapotranspiration, sweating, and drooling. Heat stress studies have reported a correlation between reduced DMI and increased dry matter digestibility for all breeds of cattle exposed to temperatures that exceed the upper critical temperatures. For that reason, diet formulation with integrated mathematical nutrition modeling can account for nutrient and animal variability, to improve total digestible nutrient values. Furthermore, the water requirement is influenced by stage and type of production, activity, diet composition, feed intake and environmental temperature. Adjustments in management practices could potentially result in reduced production losses caused by thermal heat stress. The utilization of region-specific facilities that accommodate cattle and ensure the availability and quality of drinking water will improve overall animal health and production. Cattle receiving high-concentrate diets in tropical and subtropical regions require adjustments in management and nutrition to mitigate challenges induced by heat stress environments, but improvements are warranted for required energy and water for Bos indicus breeds.


2017 ◽  
Author(s):  
Xi Lan ◽  
John C. F. Hsieh ◽  
Carl J. Schmidt ◽  
Qing Zhu ◽  
Susan J. Lamont

2020 ◽  
Vol 51 (4) ◽  
pp. 1001-1014
Author(s):  
Sulaiman & Sadiq

The experiment was conducted in a greenhouse during 2017 and 2018 growing seasons to evaluate the impact of the shading and various nutrition programs on mitigating heat stress, reducing the use of chemical minerals, improving the reproductive growth and yield of tomato plant. Split-plot within Randomized Complete Block Design (RCBD) with three replications was conducted in this study. Shading factor was allocated in the main plots and the nutrition programs distributed randomly in the subplots. Results indicate that shading resulted in the decrease of daytime temperature by 5.7˚C as an average for both seasons; thus a significant increasing was found in leaf contents of macro nutrients (Nitrogen, Phosphorous, and Potassium), and micro nutrients (Iron, Zinc and Boron), except the Iron content in 2018 growing season. Furthermore, shading improved significantly the reproductive growth and tomato yield. Among the plant nutrition programs, the integrated nutrient management (INM) including the application of organic substances, bio inoculum of AMF and 50% of the recommended dose of chemical fertilizers; lead to the enhancement of nutrients content, reproductive characteristics and plant yield. Generally, combination of both shading and INM showed positive effects on plants nutrient status and persisting balance on tomato flowering growth and fruits yield.


2016 ◽  
Vol 22 (18) ◽  
pp. 2619-2639 ◽  
Author(s):  
Biljana Miova ◽  
Maja Dimitrovska ◽  
Suzana Dinevska-Kjovkarovska ◽  
Juan V. Esplugues ◽  
Nadezda Apostolova

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 347
Author(s):  
Samikshya Bhattarai ◽  
Joshua Harvey ◽  
Desire Djidonou ◽  
Daniel Leskovar

Texas tomato production is vulnerable to extreme heat in the spring-summer cropping period, which is exacerbated by the lack of superior genetic materials that can perform well in such environments. There is a dire need for selecting superior varieties that can adapt to warm environments and exhibit high yield stability under heat stress conditions. This research aimed at identifying heat-tolerant varieties under heat-stress conditions in controlled and open-field environments and was carried out in three stages. For the first experiment, 43 varieties were screened based on yield responses in natural open-field environment. From those, 18 varieties were chosen and exposed to control (greenhouse: 26/20 °C) and constant heat-stress (growth-chamber: 34/24 °C) conditions for three months. Measurements were done for chlorophyll fluorescence, chlorophyll content (SPAD), plant height, stem diameter and heat injury index (HII). The last experiment was conducted in an open field with a pool of varieties selected from the first and second experiments. Leaf gas exchange, leaf temperature, chlorophyll fluorescence, SPAD value, electrolyte leakage, heat injury index and yield were assessed. From the combined studies, we concluded that heat-tolerant genotypes selected by using chlorophyll fluorescence and HII in controlled heat-stress conditions also exhibited heat-tolerance in open-field environments. Electrolyte leakage and HII best distinguished tomato varieties in open-field environments as plants with low electrolyte leakage and HII had higher total yield. 'Heat Master,' 'New Girl,' 'HM-1823,' 'Rally,' 'Valley Girl,' 'Celebrity,' and 'Tribeca' were identified as high heat-tolerant varieties. Through trait correlation analysis we provide a better understanding of which traits could be useful for screening and breeding other heat-tolerant tomato varieties.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bin Huang ◽  
Zhinuo Huang ◽  
Ruifang Ma ◽  
Jialu Chen ◽  
Zhijun Zhang ◽  
...  

AbstractHeat shock transcription factors (HSFs) are central elements in the regulatory network that controls plant heat stress response. They are involved in multiple transcriptional regulatory pathways and play important roles in heat stress signaling and responses to a variety of other stresses. We identified 41 members of the HSF gene family in moso bamboo, which were distributed non-uniformly across its 19 chromosomes. Phylogenetic analysis showed that the moso bamboo HSF genes could be divided into three major subfamilies; HSFs from the same subfamily shared relatively conserved gene structures and sequences and encoded similar amino acids. All HSF genes contained HSF signature domains. Subcellular localization prediction indicated that about 80% of the HSF proteins were located in the nucleus, consistent with the results of GO enrichment analysis. A large number of stress response–associated cis-regulatory elements were identified in the HSF upstream promoter sequences. Synteny analysis indicated that the HSFs in the moso bamboo genome had greater collinearity with those of rice and maize than with those of Arabidopsis and pepper. Numerous segmental duplicates were found in the moso bamboo HSF gene family. Transcriptome data indicated that the expression of a number of PeHsfs differed in response to exogenous gibberellin (GA) and naphthalene acetic acid (NAA). A number of HSF genes were highly expressed in the panicles and in young shoots, suggesting that they may have functions in reproductive growth and the early development of rapidly-growing shoots. This study provides fundamental information on members of the bamboo HSF gene family and lays a foundation for further study of their biological functions in the regulation of plant responses to adversity.


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