scholarly journals Differences in Thermoregulatory Responses between Dorper and Second Cross Lambs to Heat Stress Challenges

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 155 ◽  
Author(s):  
Aleena Joy ◽  
Frank R. Dunshea ◽  
Brain J. Leury ◽  
Kristy DiGiacomo ◽  
Iain J. Clarke ◽  
...  
Keyword(s):  
Heat Stress ◽  
Environmental Temperature ◽  
Base Excess ◽  
Physiological Responses ◽  
Blood Electrolytes ◽  
Biochemical Responses ◽  
Breed Differences ◽  
Cyclic Heat ◽  
Lactate Levels ◽  
Physiological And Biochemical

We compared the thermotolerance of Dorper (D) and second cross (SC) (Poll Dorset x Merino/Border Leicester) lambs by assessing physiological and biochemical responses. After acclimatization, 4–5 month old lambs of each breed were exposed to either thermo-neutral (18 °C–21 °C, 40%–50% RH, n = 12/group) or cyclic heat stress (HS) (28 °C–40 °C; 40%–60% RH, n = 12/group) for 2 weeks in climatic chambers. The HS involved exposure to temperatures of 38 °C–40 °C between 0800 and 17.00 h daily; otherwise the temperature was maintained at 28 °C. Elevated temperature increased rectal temperature (p < 0.01), respiration rate (p < 0.01) and skin temperature (p < 0.01) in both breeds, (data for 12.00 and 16.00 h pooled), but to a lesser extent in D than in SC lambs (p < 0.01). The HS increased (p < 0.01) water intake to a greater extent in SC than in D lambs and HS reduced (p < 0.05) food intake in SC lambs but not in D lambs. There were no treatment effects on blood glucose and lactate levels in either breed. Significant effects of breed (p < 0.01) and treatment (p < 0.01) were observed in blood creatinine levels, being higher in SC lambs. Higher pH (p < 0.01) and lower pCO2 (p < 0.01) were recorded under HS in both breeds. Among blood electrolytes, Cl−, Na+ and base excess were significantly (all p < 0.01) reduced under HS, with no breed differences. In conclusion, the attenuated physiological responses to HS in Dorper lambs indicates better adaptation of this breed to high environmental temperature.

scholarly journals Comparative Assessment of Thermotolerance in Dorper and Second-Cross (Poll Dorset/Merino × Border Leicester) Lambs

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2441
Author(s):  
Aleena Joy ◽  
Frank R. Dunshea ◽  
Brian J. Leury ◽  
Kristy DiGiacomo ◽  
Iain J. Clarke ◽  
...  
Keyword(s):  
Base Excess ◽  
Basal Respiration ◽  
Comparative Assessment ◽  
Future Research ◽  
Plasma Prolactin ◽  
Blood Electrolytes ◽  
Blood Ph ◽  
Basal Plasma ◽  
Cyclic Heat ◽  
Genotype Difference

The objective of this study was to compare the thermotolerance of second-cross (SC; Poll Dorset × Merino × Border Leicester) and Dorper lambs. Dorper and SC lambs (4–5 months of age) were subjected to cyclic heat stress (HS) (28–40 °C). The temperature was increased to 38–40 °C between 800 and 1700 h daily and maintained at 28 °C for the remainder of the day (30–60% relative humidity (RH)) in climatic chambers for 2 weeks (n = 12/group), with controls maintained in a thermoneutral (TN) (18–21 °C, 40–50% RH) environment (n = 12/group). Basal respiration rate (RR), rectal temperature (RT) and skin temperature (ST) were higher (p < 0.01) in SC lambs than in Dorpers. HS increased RR, RT and ST (p < 0.01) in both genotypes, but the levels reached during HS were lower (p < 0.01) in Dorpers. HS increased (p < 0.01) water intake to a greater extent in SC lambs, while feed intake was reduced (p < 0.05) by HS in SC lambs but not in Dorpers. HS increased (p < 0.01) blood urea nitrogen and creatinine in SC lambs only. Plasma non-esterified fatty acid concentrations were reduced (p < 0.05) by HS in SC lambs but increased (p < 0.05) in Dorpers. There was no effect of HS on pO2, cHCO3− and cSO2, but higher (p < 0.01) blood pH and lower (p < 0.01) pCO2 were recorded under HS in both genotypes. Blood electrolytes and base excess were reduced (p < 0.01) under HS, while a genotype difference (p < 0.05) was only observed in blood K+ and hemoglobin concentrations. Basal plasma prolactin concentrations were lower (p < 0.01) in Dorpers but were elevated at a similar level during HS (p < 0.01) in both genotypes. Dorper lambs are more resilient to HS than SC lambs. Future research should focus on confirming whether the better heat tolerance of Dorpers is translated to better returns in terms of growth performance and carcass traits over the summer months.

scholarly journals Effect of Cyclic Heat Stress on Feeding-Related Hypothalamic Neuropeptides of Three Broiler Populations and Their Ancestor Jungle Fowl

2021 ◽  
Vol 12 ◽  
Author(s):  
Giorgio Brugaletta ◽  
Elizabeth Greene ◽  
Travis Tabler ◽  
Sara Orlowski ◽  
Federico Sirri ◽  
...  
Keyword(s):  
Heat Stress ◽  
Environmental Temperature ◽  
Mrna Level ◽  
Genetic Selection ◽  
Molecular Data ◽  
Melanocortin Receptor ◽  
Feed Consumption ◽  
Poultry Production ◽  
Cyclic Heat ◽  
Hypothalamic Neuropeptides

Heat stress (HS) has been increasingly jeopardizing the sustainability of the poultry production. Moreover, modern high-performing chickens are far less able to withstand HS than their predecessors due to higher growth rate and metabolic rates. Performance losses caused by HS are mainly ascribed to decreases in feed consumption. Since feed intake is tightly controlled by the hypothalamic centers of hunger and satiety, we sought to determine the effect of chronic cyclic HS on the expression of feeding-related hypothalamic neuropeptides (FRHN) in unselected chickens (i.e., the ancestor junglefowl—JF) and three broiler lines from diverse stages of genetic selection (i.e., the slow growing ACRB, the moderate growing 95RN, and the fast growing MRB). From 29 to 56 days, birds (n = 150 birds for each population) were subjected to either thermoneutral (TN, 25°C) or cyclic heat stress (HS, 36°C, 0900–1,800 h) conditions. Molecular data were analyzed by two-way ANOVA with interaction between the main factors, namely environmental temperature and line. The expression of major FHRN, like neuropeptide Y, agouti-related peptide, proopiomelanocortin, and cocaine and amphetamine regulated transcript remained unchanged. However, melanocortin receptor 1 exhibited a line-dependent decreasing trend from JF to MRB under both TN and HS (p = 0.09), adiponectin expression showed a distinct trend toward significance with 95RB exhibiting the highest mRNA level irrespective of the environmental temperature (p = 0.08), and JF had a greater mRNA abundance of visfatin than ACRB under TN (p &lt; 0.05). The hypothalamic integration of circadian information, acclimation to long-lasting HS exposure, stable hypothalamic pathways unaffected by evolution and genetic selection, focus on mRNA abundances, and use of the entire hypothalamus masking gene expression in specific hypothalamic nuclei are all possible explanations for the lack of variations observed in this study. In conclusion, this is the first assessment of the impacts of heat stress on feeding-related hypothalamic neuropeptides of chicken, with a valuable and informative comparison between the ancestor junglefowl and three differently performing broiler lines.

Optimizing Animal Productivity under Heat Stress Conditions Using Conventional and Recent Technologies

2018 ◽  
Vol 1 (3) ◽  
pp. 4-16
Author(s):  
Alsaied Alnaimy Mostafa Habeeb
Keyword(s):  
Heat Stress ◽  
Protein Turnover ◽  
Biochemical Parameters ◽  
Environmental Temperature ◽  
Stress Conditions ◽  
High Environmental Temperature ◽  
Hot Climate ◽  
Induced Changes ◽  
Physiological And Biochemical ◽  
Hormonal Levels

When the animals exposed to the high environmental temperature most of the physiological and biochemical parameters are disturbances. The heat-induced changes in each of thermoregulatory parameters as well as water, protein turnover or balances and hormonal levels may be used for evaluation the animal's adaptability to hot climate. Detection of such phenomena in the animals could be achieved by different indices. Most of indices which may be used for detecting the heat adaptability in animals are reviewed in this article paper.

scholarly journals Mikroklimat, Termoregulasi dan Produktivitas Sapi Perah Friesians Holstein pada Ketinggian Tempat Berbeda

2019 ◽  
Vol 6 (1) ◽  
pp. 70
Author(s):  
Elmy Mariana ◽  
Cece Sumantri ◽  
Dewi Apri Astuti ◽  
Anneke Anggraeni ◽  
Asep Gunawan
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Environmental Temperature ◽  
Physiological Responses ◽  
Mild Stress ◽  
Altitude Effect ◽  
Temperature Humidity Index ◽  
Humidity Index ◽  
Kg Medium ◽  
Different Altitudes

ABSTRAKTujuan penelitian ini adalah untuk mengetahui pengaruh ketinggian tempat terhadap kondisi mikroklimat,termoregulasi dan produktivitas sapi Friesian-Holstein (FH). Penelitian dilakukan pada tiga lokasi dengan ketinggian berbeda, yaituPodok Ranggon (97mdpl), Ciawi (576mdpl), dan Lembang (1241mdpl). Sebanyak 63 sapi FH dalam kondisi laktasi normal digunakan dalam penelitian ini.  Aspek lingkungan meliputi suhu udara, kelembaban relatif dan Temperature-Humidity Index di dicatat setiap 2 jam dari pukul 08.00 sampai 16.00 WIB. Parameter termoregulasi yang diamati terdiri atas suhu kulit (Ts),suhu rektal (Tr), suhu tubuh (Tb), denyut jantung (Hr),laju pernapasan (Rr), dan Heat Tolerance Coeficient (HTC).Berdasarkan nilai Ta, Rr dan THI, dataran rendah memberikan dampak cekaman panas sedang, dataran sedangdan tinggi memberikan dampak cekaman panas ringan pada sapi perah. Hasil menunjukkan bahwa sapi dataran rendah memiliki Nilai HTC, Tr, Ts dan Tb tertinggi (P<0,05) dan Hr yang terendah (P<0,05). Produksi susu di ketiga lokasi penelitian berbeda nyata (P<0,05), dengan produksi susu tertinggi di dataran tinggi (13,1±3,52 kg),dataran sedang (11,3±4,73 kg) dan dataran rendah (7,0±3,36 kg). Secara umum sapi FH di dataran rendah, sedang dan tinggi tercekam panas akibat kondisi lingkungan yang berada pada kondisi di luar zona nyamanselama musim kemarau, akan tetapi mampu beradaptasi terhadap kondisi tersebut. Kata kunci: ketinggian tempat, produktivitas, sapi perah, cekaman panas, termoregulasiABSTRACTThe purpose of this research was to determine altitude effect on microclimate, thermoregulation and productivity of Friesian Holstein. Research was conducted in different altitudes, i.e.: Pondok Ranggon (97m asl), Ciawi (576m asl), and Lembang (1241 m asl). A total of 63 FH cows in normal lactation were used in this study. Microclimate aspects observation includes environmental temperature (Ta), relative humidity (RH) and Temperature-Humidity Index (THI) were recorded every 2 hours from 08.00 to 16.00. The physiological responses measurements consisted of skin temperature (Ts), rectal temperature (Tr), body temperature (Tb), heart rate (Hr), respiratory rate (Rr) and Heat Tolerance Coeficient (HTC). Lowland environmental provide moderate heat stress, while the medium and highland impacts with mild stress. The results showed that lowland cows have highest HTC, Tr, Ts and Tb (P<0.05) and lowest Hr (P<0.05). Milk production in the different altitude was significantly different (P<0.05), with the highest milk yields in the highlands (13.1±3.52 kg), medium (11.3±4.73 kg) and lowland (7.0±3.36 kg). In general, HF dairy cows in low-, medium- and highland are exposed to climatic stress during dry season conditions, although they have the ability to adapt physiologically and cope with environmental stress.  Keyworlds: altitude, dairy cattle, heat stress, productivity, physiological responses

scholarly journals Physiological and Biochemical Dissection Reveals a Trade-off Between Antioxidant Capacity and Heat Tolerance in Bread Wheat (Triticum aestivum L.)

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 351
Author(s):  
Mohammed Mohi-Ud-Din ◽  
Md. Nurealam Siddiqui ◽  
Md. Motiar Rohman ◽  
S.V. Krishna Jagadish ◽  
Jalal Uddin Ahmed ◽  
...  
Keyword(s):  
Heat Stress ◽  
Antioxidant Capacity ◽  
Heat Tolerance ◽  
Antioxidant Activities ◽  
Enzymatic Antioxidants ◽  
Wheat Seedlings ◽  
Trade Off ◽  
Biochemical Responses ◽  
Glutathione Cycle ◽  
Physiological And Biochemical

Heat stress alters photosynthetic components and the antioxidant scavenging system, negatively affecting plant growth and development. Plants overcome heat stress damage through an integrated network involving enzymatic and non-enzymatic antioxidants. This study aimed to assess physiological and biochemical responses in contrasting thermo-tolerant wheat varieties exposed to 25 °C (control) and 35 °C (heat stress), during the seedling stage. Our results revealed a substantial decrease in the photosynthetic pigments, carotenoids, anthocyanin content, and increased membrane injury index, malondialdehyde, methylglyoxal (MG), H2O2 contents and lipoxygenase activity compared to non-stress wheat seedlings. The heat-tolerant variety BARI Gom 26 (“BG26”) maintained higher cellular homeostasis compared to the heat susceptible variety Pavon 76 (“Pavon”), perpetuated by higher accumulation of proline, glycine betaine, ascorbate-glutathione cycle associated enzymes, reduced glutathione and ascorbate concentration in plant cells. Significantly lower levels of MG detoxification and antioxidant activities and ascorbate-glutathione cycle-related enzymatic activities lead to increased susceptibility in variety “Pavon”. Hierarchical clustering and principal component analysis revealed that variety “BG26” possess a combination of biochemical responses tailoring antioxidant activities that induced a higher level of tolerance. Taken together, our results provide a pipeline for establishing a trade-off between antioxidant capacity and heat tolerance to facilitate functional genomics and translational research to unravel underlying mechanisms to better adapt wheat to heat stress.

Physiological and biochemical responses of harvested rambutan (Nephelium lappaceum L.) fruits to postharvest dip treatments during storage

2018 ◽  
Vol 19 (1&2) ◽  
pp. 217-222
Author(s):  
Manjunath J. Shetty ◽  
◽  
P.R. Geethalekshmi ◽  
C. Mini ◽  
Vijayaraghava Kumar ◽  
...  
Keyword(s):  
Biochemical Responses ◽  
Nephelium Lappaceum ◽  
Physiological And Biochemical

Morphological, Physiological and Biochemical Responses of Poplar Plants to Drought Stress

2018 ◽  
Vol 5 (03) ◽  
Author(s):  
ARADHNA KUMARI ◽  
IM KHAN ◽  
ANIL KUMAR SINGH ◽  
SANTOSH KUMAR SINGH
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Biochemical Parameters ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Field Capacity ◽  
Drought Event ◽  
Total Biomass ◽  
Biochemical Responses ◽  
Physiological And Biochemical

Poplar clone Kranti was selected to assess the morphological, physiological and biochemical responses under drought at different levels of water stress, as it is a common clone used to be grown in Uttarakhand for making paper and plywood. The cuttings of Populus deltoides L. (clone Kranti) were exposed to four different watering regimes (100, 75, 50 and 25% of the field capacity) and changes in physiological and biochemical parameters related with drought tolerance were recorded. Alterations in physiological (i.e. decrease in relative water content) and biochemical parameters (i.e. increase in proline and soluble sugar content and build-up of malondialdehyde by-products) occurred in all the three levels of water stress, although drought represented the major determinant. Drought treatments (75%, 50% and 25% FC) decreased plant height, radial stem diameter, harvest index, total biomass content and RWC in all the three watering regimes compared to control (100% FC). Biochemical parameters like proline, soluble sugar and MDA content increased with severity and duration of stress, which helped plants to survive under severe stress. It was analyzed that for better wood yield poplar seedlings should avail either optimum amount of water (amount nearly equal to field capacity of soil) or maximum withdrawal up to 75% of field capacity up to seedling establishment period (60 days). Furthermore, this study manifested that acclimation to drought stress is related with the rapidity, severity, and duration of the drought event of the poplar species.

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