scholarly journals Effects of ambient temperature on body size and organ development in broilers

Author(s):  
Qiao Yingying ◽  
Oleksandr Kyselov ◽  
Liu Changzhong

The current study investigated the effect of poultry house temperature change on the growth and development of both broiler chickens themselves and the development of their individual organs. Following 42 days of rearing, results showed that the body oblique length, chest width, chest depth, chest angle, keel length, pelvic width, and tibial length of broilers in the low temperature group were significantly lower than those of the control group (P<0.05), while the breast depth of broiler chickens in the high-temperature group was significantly lower than those in the control group (P<0.05). Furthermore, low temperatures significantly increased the function of the heart, liver, spleen and pancreas of broiler chickens (P<0.05). After 7 days of rearing, the bursal index of broilers in the high temperature group was significantly higher than in the control group as well as in the low temperature group (P<0.05). Previous research has established that high and low temperatures significantly affect the growth and development as well as the immunity of broiler chickens, namely that low environmental temperatures have a more adverse effect on broiler chickens than high temperatures. Consequently, using and maintaining high temperatures early in rearing helps to improve the immunity of broilers and improve their performance. The results of our study provides an opportunity to provide both a theoretical and a practical basis for accurate temperature setting in poultry houses for effective breeding of broiler chickens, which will make it possible to increase the productivity of broiler chickens and increase the economic efficiency of the poultry house. Key words: temperature, breeding, body weight, organ development, broilers chickens.

Author(s):  
Yingying Qiao ◽  
Oleksandr Kyselov ◽  
Changzhong Liu

The experiment aims to study the effects of long-term relatively high and low temperatures on growth performance and meat quality of broiler chickens. The experiment was carried out in Yunnan Academy of Animal Science, for determine the quality of meat used the laboratories of Henan Institute of Science and Technology. A total of experiment use 240 healthy 1-day-old Avian broiler chickens were randomly divided into three groups: relatively high temperature group, low temperature group and control group. The results of the experiment confirm that at low temperatures, when the energy consumption of the animal decreases, it leads to weight loss, which we can see in the low-temperature group, the average daily weight gain in this experiment was significantly lower than in the control group (P <0.05). It was found that low-temperature stress significantly increased the mortality of broilers, at the age of 42 days in the low-temperature group, the mortality of chickens was higher than in the control group, by 71.4%. Among all evaluated groups on the content of unsaturated fatty acids SFA, PUFA, MUFA and EFA in the muscles of the breasts of broilers, the lowest content was in the lower temperature group than in the control group, by 48.3%, 46.9%, 51.5% and 43.9%. Studies have shown that influence of high-temperature above 30°C causes disturbances in poultry behavior and physiology, leading to reduced production performance. Broilers aged 35-40 days experienced 31°C high-temperature stress and found that their performance and immunity decreased. Broilers feed intake and growth rate at 35°C high temperature were reduced by 13% and 32% than at 20°C. The results showed that: ① Relatively high temperature and low temperature for a long time reduced the growth performance and mortality of broilers, and long-term relatively low temperature decreased the slaughter performance of broilers.② Relatively high and low temperatures for a long period of time reduced the levels of serine, glycine, SFA, PUFA, USFA, EFA and MUFA in broiler breast muscles negative effect on meat quality. ③ The long-term relatively low temperature has a greater adverse effect on broilers than the long-term relatively high temperature. The results provided some theoretical basis for accurately setting the broiler breeding environment temperature, improving broiler quality, maximizing broiler production performance, and increasing the economic benefits of the farm.


1969 ◽  
Vol 47 (2) ◽  
pp. 217-224 ◽  
Author(s):  
C. A. Barlow ◽  
W. D. Kerr

The speed or orthokinesis and turning rates or klinokinesis of individual adults of the grain weevil, Sitophilus granarius (L.), were affected by both the rearing temperature and the testing temperature. In general, orthokinesis decreased with a decrease in temperature, but weevils reared at a low temperature showed a smaller decrease than those reared at a high temperature. Klinokinesis was greater when differences between rearing and test temperatures were large and least when the differences were small or absent. Effects of differences between rearing and test temperatures were less if weevils were kept at the test temperature for 24 hours before testing and absent if beetles were at the test temperature for 2 weeks. Orthokinesis was shown to be an unsatisfactory orientation mechanism at low temperatures although it may operate with some efficiency at moderately high temperatures. Klinokinesis was much more effective at extreme temperatures and is probably the chief locomotory mechanism of orientation to temperature in this species.


1961 ◽  
Vol 34 (1) ◽  
pp. 57-65
Author(s):  
A. I. Lukomskaya

Abstract 1. The reinforcing action of carbon blacks is most clearly apparent in the knotty tearing of carbon black rubbers. 2. Knotty tearing is characteristic of rubbers filled with carbon black in definite ranges of deformation and temperature, the position of which depends upon the type of rubber and carbon black. 3. With high contents of contact gas black in vulcanizates of sodium butadiene (SKB) and butadiene sytrene (SKS-30) rubbers two ranges of knotty tearing occur. The first is situated at relatively high temperatures and low rates and the second at relatively low temperatures and higher rates. Reduction in the content of black in these vulcanizates leads to the disappearance of the high temperature range of knotty tearing and the displacement of the low-temperature range towards higher temperatures and low rates. This position of the ranges (at medium rates and temperatures) is characteristic also of the said synthetic rubbers containing thermal black. 4. The first range of knotty tearing of filled SKB and SKS-30 vulcanizates with contact black is linked with the presence in them of carbon black chains, while the second range, existing also with vulcanizates with thermal black, is connected with the presence of carbon black particles. 5. Within the ranges ofr ates from 40 to 1000 mm/min and of temperatures from 40 to +100° C filled vulcanizates of natural rubber have one range of knotty tearing situated at lower rates. In the case of the presence in them of contact gas black the range is shifted towards higher rates than in the case of thermal black. 6. Increasing the length of the nick in testpieces being tested for tear propagation leads to a shift in the range of knotty tearing towards higher rates and widens it with respect to temperatures. This same effect is noted on altering the shape of the testpiece, starting with the Delft testpieces and proceeding to types A, B, and C, i.e. increasing the nonuniformity of stress distribution in the deformed testpieces.


2021 ◽  
Author(s):  
Zhe Li ◽  
Luting Wen ◽  
Xia Wu ◽  
Junqi Qin ◽  
Zhong Chen ◽  
...  

Abstract Low temperatures limit the development of Oreochromis niloticus (tilapia), and an increase in low-temperature tolerance would increase yields. We studied the responses of tilapia to low temperatures. The fish were labeled CK, AA, BB, and CC based on treatment (25°C, 12°C/1 h, 12°C/24 h, and 12°C/48 h, respectively) with CK being the control group. We examined the transcriptome responses and the Na+/K+-ATPase activity of gill tissue in each group. The Na+/K+-ATPase activity varied with the treatment time. Transcriptome sequencing of 12 individuals yielded 585.51 million clean reads, and at least 83.26% of the genes were mapped to the reference genome. Comparative analysis revealed 12,448 genes with significantly differential expression, including 792, 1,827, 1,924 upregulated genes and 992, 3,056, 3,857 genes downregulated for AA, BB, and CC, respectively. Differentially expressed genes (DEGs) were validated using RT-PCR for five genes. Functional annotation analysis of the DEGs identified functions associated with response to low-temperature stress. When tilapia was subjected to low-temperature stress, expression changes occurred in genes associated with cytokine-cytokine receptor interaction, metabolic pathways, cell adhesion molecules, material transport, and immunity. The founding will help understand the effects of low temperature on fish and provide a theoretical basis for the tilapia breeding industry.


1999 ◽  
Vol 14 (3) ◽  
pp. 715-728 ◽  
Author(s):  
P. Zhao ◽  
D. G. Morris ◽  
M. A. Morris Munoz

High-temperature forging experiments have been carried out by axial compression testing on a Fe–41Al–2Cr alloy in order to determine the deformation systems operating under such high-speed, high-temperature conditions, and to examine the textures produced by such deformation and during subsequent annealing to recrystallize. Deformation is deduced to take place by the operation of 〈111〉 {110} and 〈111〉{112} slip systems at low temperatures and by 〈100〉{001} and 〈100〉{011} slip systems at high temperatures, with the formation of the expected strong 〈111〉 textures. The examination of the weak 〈100〉 texture component is critical to distinguishing the operating slip system. Both texture and dislocation analyses are consistent with the operation of these deformation systems. Recrystallization takes place extremely quickly at high temperatures (above 800 °C), that is within seconds after deformation and also dynamically during deformation itself. Recrystallization changes the texture such that 〈100〉 textures superimpose on the deformation texture. The flow stress peak observed during forging is found at a very high temperature. Possible origins of the peak are examined in terms of the operating slip systems.


2021 ◽  
Vol 887 ◽  
pp. 651-656
Author(s):  
Marina V. Polonik

On the basis of previously accumulated irreversible deformations, and, consequently, residual stresses, the process of removing residual stresses in metal workpieces under the action of low and high temperatures is simulated. Boundary value problems are solved and here are described regularities that are responsible for removing residual stresses for processing modes: high-temperature heating - cooling, high-temperature heating - holding - cooling, low-temperature heating - holding - cooling. The holding stage is modeled, taking into account the creep properties of materials under Norton creep conditions. According to the dependences of the obtained exact solutions, it is shown that it is the holding process that leads to the relaxation of residual stresses.


2003 ◽  
Vol 805 ◽  
Author(s):  
Günter Krauss ◽  
Sofia Deloudi ◽  
Andrea Steiner ◽  
Walter Steurer ◽  
Amy R. Ross ◽  
...  

ABSTRACTThe stability of single-crystalline icosahedral Cd-Yb was investigated using X-ray diffraction methods in the temperature range 20 K ≤ T ≤ 900 K at ambient pressure and from ambient temperature to 873 K at about 9 GPa. Single-crystals remain stable at low temperatures and in the investigated HP-HT-regime. At high temperatures and ambient pressure, the quasicrystal decomposes. The application of mechanical stress at low temperatures yields to the same decomposition, the formation of Cd. A reaction of icosahedral Cd-Yb with traces of oxygen or water causing the decomposition seems reasonable, but a low-temperature instability of this binary quasi-crystal cannot be ruled out totally.


Weed Science ◽  
1986 ◽  
Vol 34 (1) ◽  
pp. 101-105 ◽  
Author(s):  
John D. Nalewaja ◽  
Grzegorz Skrzypczak

Experiments in controlled-environment chambers indicated that high temperature, 30 C, increased the phytotoxicity of bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) to wild mustard (Sinapis arvensisL. # SINAR) and redroot pigweed (Amaranthus retroflexusL. # AMARE) compared to low temperature, 10 C, during and after treatment. Bromoxynil phytotoxicity generally was higher at relative humidities of 90 to 95% compared to 40 to 60%, but relative humidity had less influence on bromoxynil phytotoxicity than did temperature. A simulated rain immediately after bromoxynil treatment reduced control of both species, but the reduction was of no practical importance for wild mustard. The data indicate that wild mustard and redroot pigweed control would be reduced by bromoxynil application during a period of low temperatures or to plants in advanced growth stages.


1995 ◽  
Vol 22 (5) ◽  
pp. 783 ◽  
Author(s):  
DJ Batten ◽  
CA Mcconchie

Buds of potted plants of the terminal flowering tree species lychee (Litchi chinensis) and mango (Mangifera indica) forced to begin growth at high temperatures (florally non-inductive) and then transferred to low temperatures produced inflorescences, so the whole process of floral induction can occur in growing buds. Floral initials were visible in lychee within 39 days of transfer to low temperature and 30 days in mango, indicating that floral induction occurs relatively quickly in both species. In most cases where plants were transferred to winter ambient temperatures for floral induction, pre-activated (growing) buds flowered more consistently than buds that were dormant at the time of transfer. If the buds were small when plants were transferred from high temperature to low temperature, leafless inflorescences formed. If buds were a little larger, leafy inflorescences formed, with leaves basally and flowers terminally. If the buds were larger again, the shoots were purely vegetative. All these observations are consistent with floral induction occuning while the bud is growing and provide for much improved experimental systems for studying the physiology of floral induction in species such as lychee and mango.


1982 ◽  
Vol 75 (1) ◽  
pp. 53-55
Author(s):  
George Knill ◽  
George Fawceti

Everyone knows that wood bums at a very high temperature. This burning is a chemical process that combines oxygen and carbon. The process occurs at very low temperatures as well as at very high ones. At high temperatures the process is spectacular-fire. At low temperatures (room temperature) you won’t even notice it, although it is still going on. Wood is always burning.


Sign in / Sign up

Export Citation Format

Share Document