scholarly journals Genetic adaptive potentials of four breeds of rabbit to heat stress in the humid tropics

2021 ◽  
Vol 43 (1) ◽  
pp. 93-99
Author(s):  
A. O. Fadare ◽  
T. Oni ◽  
I. L. Olatunji ◽  
O. A. Mesogboriwon
Keyword(s):  
Heat Stress ◽  
New Zealand ◽  
Respiratory Rate ◽  
Pulse Rate ◽  
Rectal Temperature ◽  
Dry Season ◽  
Humid Tropics ◽  
Stress Index ◽  
Tropical Conditions ◽  
Heat Stress Index

Rabbit production under tropical conditions is affected by environmental stress mainly from the effect of high ambient temperatures and high humidity, low wind speed and indirect solar radiation. This experiment was conducted to investigate the adaptive potentials of Californian, New Zealand white, Havana black and Palomino brown rabbits to heat stress when raised in humid tropics. A total number of ninety-six rabbits were used. Rectal temperature, respiratory rate, pulse rate and heat stress index were measured in these temperate breeds during rainy and dry season. The results showed that the breed of rabbit had a significant effect (P<0.05) on rectal temperature, respiratory rate, pulse rate and heat stress index. Havana black rabbit had the highest mean rectal temperature value (39.32 ± 0.03°C) followed by Palomino brown (38.97 ± 0.03°C), while the least value was recorded for New Zealand white (38.68 ± 0.02). Respiratory rate values followed the same pattern with that of rectal temperature with higher respiratory rate 69.09 ± 1.05 breaths/min recorded for Havana rabbits. The pulse rate values ranged from 163.23 ± 0.47 - 184.35 ± 0.78 beats/minutes. The highest pulse rate of 184.35 ± 3.78beats/minute was recorded for Havana black. The lowest heat stress index was obtained for New Zealand white followed by California and Palomino Brown while Havana black rabbit had the highest value (1.95± 0.01). The respiratory rate was significantly lower among males as compared to their female counterparts (63.09±0.58 versus 69.54 ± 1.65breaths per minute). The age of the rabbit also significantly affected (P<0.05) the rectal temperature, respiratory rate, pulse rate and heat stress index. 12 weeks old rabbit had the highest mean values while 4 weeks old rabbit had the least values. The heat stress index value obtained during dry season was higher (P< 0.05) than that obtained for rainy season (1.93± 0.02 versus 1.80 ± 0.01). Havana black rabbits and Palomino brown were more prone to heat stress than California and New Zealand white rabbits in tropical environment.

scholarly journals The Influence of Microclimatic Ammonia Changes in Closed House on Broiler’s Performance in Dry Season

2019 ◽  
Vol 20 (2) ◽  
pp. 125
Author(s):  
Ica Putri Angkeke ◽  
Teysar Adi Sarjana ◽  
Edjeng Suprijatna
Keyword(s):  
Body Weight ◽  
Heat Stress ◽  
Body Weight Gain ◽  
Dry Season ◽  
Feed Consumption ◽  
Stress Index ◽  
Initial Weight ◽  
Feed Cost ◽  
Heat Stress Index ◽  
The Impact

This research aims at investigating the impact of microclimatic ammonia change on Broiler’s  performance in closed house during dry season. Seven hundred and twenty broiler’s with their initial weight of 49.29 ± 1.13 grams are kept in a 60 x 12 m2 cage.The research consists of 4 treatments and 6 experiment units. The microclimatic ammonia change is measured at a distance of 0, ¼, ½, and ¾ of closed house’s length from the inlet. The parameters observed are feed consumption, body weight gain (BWG), feed convertion ratio (FCR), performance index (PI) and Income Over Feed Cost (IOFC). The obtained data are subjected to analysis of variance and several data related to microclimatic ammonia and heat stress index (HSI) are also calculted for their correlation to find out their correlation with the broiler’s’s performance. The research results indicate that the microclimatic ammonia change significantly reduces Broiler’s performance. This is shown by the significant increase of FCR value, decrease of feed consumption, BWG, PI and IOFC (P≤0.05) starting from a distance of ¼ of cage length from the inlet. The correlation analysis result shows a negative, significant correlation between performance with ammonia, while HSI does not show any correlation with the observed parameters. The conclusion of this research is that the increase in microclimatic ammonia at increasingly further distance from the inlet decreases Broiler’s  performance in dry season.

scholarly journals Most Appropriate Heat Stress Index for Half-blood Dairy Heifers

2017 ◽  
Vol 45 (1) ◽  
pp. 8 ◽  
Author(s):  
Patrícia Kelly de Moraes Brettas ◽  
Mara Regina Bueno de Mattos Nascimento ◽  
Ednaldo Carvalo Guimarães ◽  
Gabriella Pereira Souza
Keyword(s):  
Heat Stress ◽  
Wind Speed ◽  
Respiratory Rate ◽  
Stress Index ◽  
Equivalent Temperature ◽  
Temperature Index ◽  
Dairy Heifers ◽  
Physiological Variables ◽  
Heat Stress Index ◽  
Radiant Temperature

Background: Heat stress indexes integrate several variables of the thermal environment in a single figure and predict their impact on animal welfare and performance. The correct interpretation of these indexes is of help in the choice of more adequate measures to attenuate the stress caused by the heat. Therefore, the aim of this research is to examine some of the heat stress indexes mentioned in the literature and to decide which ones best reflect the potential impact of meteorological conditions on the thermal homeostasis of half-blood dairy heifers bred in Uberlândia, Triângulo Mineiro area, Minas Gerais, Brazil.Materials, Methods & Results: Eight half-blood dairy heifers were exposed to direct sunlight from 9 h to 13 h in the months of November and December of 2016, and also January and February of 2017, 5 days per month on average, in Uberlândia, MG, Brazil. After this challenge, the respiratory rate and the rectal temperature were measured. Simultaneously to the collection of physiological variables, the temperatures of dry bulb and wet bulb, as well as that of black globe, were quantified, as was the wind speed. Afterwards, the solar radiation, the relative humidity, the mean radiant temperature and some heat stress indexes were calculated, the latter being Temperature-Humidity Index, Black Globe-Humidity Index, Equivalent Temperature Index, Environmental Stress Index, Respiratory Rate Index, Thermal Load Index, Environmental Specification Index, Thermal Comfort Index for Dairy Cattle, Comprehensive Climate Index and Cattle Heat Stress Index. These indexes were, then, correlated with the physiological variables. The averages of room temperature, black globe temperature, solar radiation, wind speed, radiant temperature and relative humidity were, respectively, 29.96°C, 41.73°C, 831.02 W/m2, 0.11 m/s-1, 318.14 K and 50.51%. Rectal temperature averaged 38.8ºC while respiratory rate averaged 41.97 breaths per minute-1. Correlating the 10 heat stress indexes with these two physiological variables, it was verified that the highest values, with a confidence of 95%, were demonstrated by the Equivalent Temperature Index (0.200 and 0.317, respectively), followed by the Cattle Heat Stress Index (0.186 and 0.314, respectively).Discussion: Room temperature was within the thermoneutral zone for half-blood dairy cattle. Nevertheless, the mean radiant temperature and the black globe temperature were higher, due to intense solar radiation. Wind speed was not very expressive and relative humidity was close to what was required. The average values of rectal temperature and respiratory rate were normal, which indicated the heifers are adapted to the thermal environment. Regarding the heat stress indexes, the Equivalent Temperature Index was recommended, as it presented the highest amount of meaningful correlations with the physiological variables, followed by the Cattle Heat Stress Index and the Environmental Stress Index. The average value of the Equivalent Temperature Index remained in the “caution” category, according to the literature’s two existing scales for interpretation of said index’s results, indicating the occurrence of stress by heat, albeit not severe. In conclusion, the Equivalent Temperature Index is considered the most appropriate heat stress index for evaluating a heat stress situation in half-blood dairy heifers bred in Uberlândia, Triângulo Mineiro, followed by the Cattle Heat Stress Index and the Environmental Stress Index.

scholarly journals Breed and seasonal variation in thermoregulatory paramters of some selected Nigerian indigenous cattle

2021 ◽  
Vol 47 (6) ◽  
pp. 18-31
Author(s):  
H. Y. Abbaya ◽  
I. I. Adedibu ◽  
M. Kabir ◽  
A. O. Iyiola-Tunji
Keyword(s):  
Heat Stress ◽  
Seasonal Variation ◽  
Respiratory Rate ◽  
Pulse Rate ◽  
Heat Tolerance ◽  
Rectal Temperature ◽  
Indigenous Cattle ◽  
Fréquence Cardiaque ◽  
Stress Thermique ◽  
Breed Differences

The study was conducted to evaluate breed differences in thermoregulatory parameters of four Nigerian indigenous breeds of cattle over two seasons (late rainy and late dry). Data on thermoregulatory parameters (rectal temperature, respiratory rate, pulse rate and Heat Tolerance Coefficient) of eighty (80) cattle, comprising 20 each of Bunaji, Rahaji, Bokoloji and Adamawa Gudali were obtained and subjected to analysis of variance of SAS software. In the pooled breed variation, breed influenced (p<0.05) all the parameters measured. Bunaji recorded the highest rectal temperature (37.92oC) in all the seasons of measurement. Respiratory rate and Heat tolerance coefficient were highest in Bokoloji while the least were in Bunaji and Adamawa Gudali. Season significantly (p<0.05) affected thermoregulatory parameters measured except (p>0.05) rectal temperature. The highest recorded values of respiratory rate (27.85 beat/min), Pulse rate (27.62breaths/min) and HTC (2.19) were in the late dry season. The effect of interaction between breed and season on thermoregulatory parameters significantly affected (p<0.05) all the thermoregulatory parameters measured. It was concluded that Bokoloji and Bunaji breeds of indigenous cattle are more reactive to Heat stress than Rahaji and Adamawa Gudali even though this could vary with seasons of the year as seen in the interaction between breed and season in this study.   L'étude a été menée pour évaluer les différences entre les races dans les paramètres thermorégulateurs de quatre races indigènes de bétail nigérianes sur deux saisons (pluvieuse tardive et sèche tardive). Des données sur les paramètres thermorégulateurs (température rectale, fréquence respiratoire, fréquence du pouls et coefficient de tolérance à la chaleur) de quatre-vingts (80) bovins, comprenant 20 de chacun de Bunaji, Rahaji, Bokoloji et Adamawa Gudali ont été obtenues et soumises à l'analyse de variance du logiciel 'SAS'. Dans la variation de race combinée, la race a influencé (p <0,05) tous les paramètres mesurés. Bunaji a enregistré la température rectale la plus élevée (37,920 ° C) de toutes les saisons de mesure. La fréquence respiratoire et le coefficient de tolérance à la chaleur étaient les plus élevés à Bokoloji tandis que les plus faibles étaient à Bunaji et à Adamawa Gudali. La saison a affecté significativement (p <0,05) les paramètres thermorégulateurs mesurés sauf (p> 0,05) la température rectale. Les valeurs les plus élevées enregistrées de la fréquence respiratoire étaient (27,85 battements / min), la fréquence cardiaque (27,62 respirations / min) et le 'HTC' (2,19) étaient à la fin de la saison sèche.L'effet de l'interaction entre la race et la saison sur les paramètres thermorégulateurs était significativement affecté (p <0,05) tous les paramètres thermorégulateurs mesurés. Il a été conclu que les races Bokoloji et Bunaji de bovins indigènes sont plus réactives au stress thermique que Rahaji et Adamawa Gudali, même si cela peut varier avec les saisons de l'année, comme le montre l'interaction entre la race et la saison dans cette étude.

scholarly journals Deforestation and climate change are projected to increase heat stress risk in the Brazilian Amazon

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Beatriz Fátima Alves de Oliveira ◽  
Marcus J. Bottino ◽  
Paulo Nobre ◽  
Carlos A. Nobre
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Amazon Basin ◽  
Stress Index ◽  
Climate Change Scenarios ◽  
Stress Exposure ◽  
Extreme Risk ◽  
High Emission ◽  
Heat Stress Index ◽  
The Impact

AbstractLand use change and deforestation can influence local temperature and climate. Here we use a coupled ocean-atmosphere model to assess the impact of savannization of the Amazon Basin on the wet-bulb globe temperature heat stress index under two climate change scenarios (RCP4.5 and RCP8.5). We find that heat stress exposure due to deforestation was comparable to the effect of climate change under RCP8.5. Our findings suggest that heat stress index could exceed the human adaptation limit by 2100 under the combined effects of Amazon savannization and climate change. Moreover, we find that risk of heat stress exposure was highest in Northern Brazil and among the most socially vulnerable. We suggest that by 2100, savannization of the Amazon will lead to more than 11 million people will be exposed heat stress that poses an extreme risk to human health under a high emission scenario.

scholarly journals Influence of sex, reproductive status and foetal number on erythrocyte osmotic fragility, haematological and physiologic parameters in goats during the hot-dry season

2014 ◽  
Vol 59 (No. 10) ◽  
pp. 479-490 ◽  
Author(s):  
B. Habibu ◽  
MU Kawu ◽  
HJ Makun ◽  
T. Aluwong ◽  
LS Yaqub ◽  
...  
Keyword(s):  
Heat Stress ◽  
Rectal Temperature ◽  
Osmotic Fragility ◽  
Dry Season ◽  
Corpuscular Haemoglobin ◽  
Physiological Variables ◽  
Erythrocyte Osmotic Fragility ◽  
Hot Dry Season ◽  
Mean Corpuscular Haemoglobin ◽  
Twin Pregnancies

The current study was aimed at evaluating the effect of heat stress (during the hot-dry period) on some physiological variables, haematology and erythrocyte osmotic fragility (EOF) in bucks, pregnant (single and twin) and lactating Red Sokoto (RS) goats. Forty apparently healthy adult goats were used for the study and were allotted to four groups [bucks (n = 10), pregnant (n = 10) dry (n = 10), and lactating (n = 10) does]. The pregnant goats were further re-grouped according to number of foetuses (single foetus, n = 5 and twins, n = 5). The temperature-humidity index and physiological variables measured were significantly higher in the afternoon compared to morning hours. Pregnant does had higher respiratory and pulse rates than the dry does, but no significant change (P &gt; 0.05) in rectal temperature was observed between groups. On the basis of sex, bucks had lower (P &lt; 0.05) mean corpuscular volume (MCV) than other groups, in addition to having higher (P &lt; 0.01) mean corpuscular haemoglobin (MCH) and total leucocyte counts than dry does. Pregnant does exhibited significantly lower (P &lt; 0.05) packed cell volume, but significantly higher (P &lt; 0.05) MCH and mean corpuscular haemoglobin concentrations (MCHC) than lactating does. Does with a single foetus had significantly lower (P &lt; 0.05) MCV, but higher MCHC than does with twin pregnancies. Using EOF as a biomarker of oxidative stress, erythrocytes of bucks were significantly more resistant to hypotonic haemolysis than those of dry, pregnant and lactating does, with no significant difference in EOF between does of different groups. The erythrocytes of single and twin pregnancies showed similar haemolysis pattern. In conclusion, sex, lactation, and the number of foetuses carried by pregnant does significantly influences physiological and haematological variables in RS goats during the hot-dry season. Also, during heat stress, the changes in physiological variables seem to enhance favourable adaptation by preventing an increase in rectal temperature even in twin pregnancies. &nbsp;

A new outdoor environmental heat index (OEHI) as a simple and applicable heat stress index for evaluation of outdoor workers

Urban Climate ◽  
2019 ◽  
Vol 29 ◽  
pp. 100479 ◽  
Author(s):  
Farideh Golbabaei ◽  
Hamidreza Heidari ◽  
Aliakbar Shamsipour ◽  
Abbas Rahimi Forushani ◽  
Abbasali Gaeini
Keyword(s):  
Heat Stress ◽  
Heat Index ◽  
Stress Index ◽  
Outdoor Workers ◽  
Heat Stress Index

The coat and heat retention in cattle: studies in the tropical maritime climate of Fiji

1977 ◽  
Vol 88 (1) ◽  
pp. 223-226 ◽  
Author(s):  
N. T. M. Yeates
Keyword(s):  
Heat Stress ◽  
New Zealand ◽  
Heat Tolerance ◽  
Humid Tropics ◽  
Day Length ◽  
Humid Climate ◽  
Maritime Climate

SUMMARYHeat-tolerance tests and observations on coat shedding were made on Santa Gertrudis and Hereford heifers of similar age in the warm humid climate of Fiji.Coat shedding (which is influenced by day length) was normal in the locally bred, smooth-coated Santa Gertrudis whose heat-tolerance was good. However, the Herefords, which had come from New Zealand and had very woolly coats failed to shed properly and suffered serious heat stress.Clipping and the use of a close-fitting jute rug demonstrated the specially high heatretaining properties of a thick natural coat of cattle hair; also the special need to select animals of low coat score for the very humid tropics.

Changes of WBGT as a heat stress index over the time: A systematic review and meta-analysis

Urban Climate ◽  
2019 ◽  
Vol 27 ◽  
pp. 284-292 ◽  
Author(s):  
Hojatollah Kakaei ◽  
Fariborz Omidi ◽  
Roohollah Ghasemi ◽  
Maryam Ramin Sabet ◽  
Farideh Golbabaei
Keyword(s):  
Systematic Review ◽  
Heat Stress ◽  
Meta Analysis ◽  
Stress Index ◽  
Heat Stress Index
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