Temperature In Broiler Chickens Research Articles

Physiological Response of Broiler Chicken To Cage Temperature

This study aims to study the physiological response shown by broiler chickens to cage temperatures at different times. A completely randomised design was used in this research, with three treatments and five replications of each. The treatments were the average temperature of the cage in the afternoon (30.15oC) , afternoon (27.04oC), and morning (26.01 °C). Each treatment was repeated six times, and each replication consisted of 5 chickens. The variables measured in this study are respiratory rate, heart rate, and rectal temperature in broiler chickens. If the results of the analysis of variance show that there is a significant difference between treatments, it is continued with the Duncan Multiple Range test. The results showed that the temperature of the cage during the day significantly increased the frequency of breathing of broiler chickens (74.90 times/minute), heart rate (279.50 times/minute), and rectal temperature (41.53 oC) compared to the frequency of breathing (57 times). ,27 times/minute and 55.77 times/minute), heart rate (274.07 times/minute and 272.47 times/minute), and rectal temperature (40.74oC and 40.61oC) In the afternoon and the morning, it can be concluded that the temperature of the cage during the day resulted in the frequency of breathing, heart rate and rectal temperature in broilers which were significantly higher than the temperature of the cell in the afternoon and morning, while the temperature of the cell in In the afternoon, the respiratory frequency, heart rate, and rectal temperature were not significantly higher than the cage temperature in the morning.

Energy requirements for maintenance as a function of body weight and critical temperature in broiler chickens

The rate of heat loss (HL) decreases as body weight (BW) increases, and this rate of HL is affected by environmental temperature (T); thus, a relashionship between BW and T on energy metabolism is expected. Therefore, this study was conducted to evaluate the relashionship between body weight (BW) and T on fasting heat production (FHP). A total of six respirometry chambers coupled with an indirect calorimetric system were used to measure the FHP of 76 groups of male broiler chickens (Cobb 500) subjected to different temperatures. The chamber temperatures were set to get temperatures below and above the Cobb 500 guideline recommendation for each age ranging from 15 to 36 °C. The average BW of these 76 groups of broiler chickens ranged from 0.20 to 3.30 kg (1 to 45 d). The BW, temperature, and FHP data were used to fit the simultaneous model. The procedure used in this study assumed two main stages: (i) how the CT ( °C) is affected by BW size and (ii) how the FHP changes according to T. To solve the first stage (i), the one-phase exponential decay was used to relate CT as a function of BW (1 - CT = c + (d - c) × e − R×BW). To solve the second stage (ii), a line-line regression was used to describe the amount of energy used (kcal/(kg0.75 × °C)) above FHP assuming a single CT (2 - FHPkcal/bird = BWb × [L + U × (CT - T) × (T < CT) + V × (T - CT) × (T ≥ CT)]). The CT term in equation 2 was replaced by equation 1, allowing for the building of a simultaneous model. A previous analysis showed that FHP was proportional to BW raised to the power of 0.75; thus this allometric scaling was used to adjust the full model. The fitted model was as follows: FHPkcal/bird = BW0.75 × [84.98 + 2.65 × (CT - T) × (T < CT) + 4.41 × (T - CT) × (T ≥ CT)], where CT = 22.46 + (35.83 - 22.46) × e − 0.4906×BW, BW is body weight (kg) and T is temperature ( °C). In the current study, the simultaneous regression analysis indicated that the CT decreases as BW increases, while the energy corrections outside CT are 2.70 and 4.07 kcal/kg0.75( °C × d) for temperatures below and above CT, respectively.

Reducing Sharp Fluctuations in Body Temperature and Optimizing Production Index of Broilers Using Dietary Electrolytes

A degree centigrade fall or rise in body temperature of broiler chickens is sufficient to reduce performance, alter sound physiological state and divert nutritional metabolism in quest for ensuring thermal balance. Thermoregulatory mechanisms of newly hatched chicks are poorly developed, and fluctuations in brooding temperature coupled with severe environmental temperatures in the tropics could threaten the survivability, production and economic integrity of fast-growing strains of broilers. However, information on the effect of sharp fluctuations in body temperature on nutrient intake and European production index (EPI) of broilers fed dietary electrolytes is scanty and thus investigated. Using a total of 300, one-day-old unsexed broiler chicks (Arbor Acre) that were randomly allotted to six dietary treatments (T1-210, T2-240, T3270, T4-300, T5-330 and T6-360 mEq/kg electrolyte balance), data on performance characteristics and their correlations with body temperature and EPI at prestarter, starter and finisher phases were determined using standard procedures. Data were analysed using descriptive statistics and ANOVA at α = 0.05. At prestarter phase, feed intake (FI) had a strong and positive relationship with protein intake (r = 1.00; p < 0.01), EPI (r = 0.96; p < 0.01) and potassium (K) intake (r = 0.66; p < 0.01), but was negatively correlated with temperature change (r = ?0.39; p < 0.05). However, FI was not significantly correlated with body weight (BW), body weight gain (BWG), sodium (Na) and water intake. At starter phase, EPI was positively correlated to K intake (r = 0.38; p < 0.05), but not Na and chloride (Cl) intake. European production index of starter chicks could be enhanced by increasing the level of K intake through dietary supplementation up to 1.02%. Weight gain was adversely affected by sharp changes in temperature at finisher phase. Increase in water intake may not be a remedial tool in lowering sharp fluctuations in body temperature. However, sharp fluctuation in body temperature of broilers was reduced with DEB of 330, 270 and 240 mEq/kg at prestarter, starter and finisher phases, respectively.

Diurnal rhythms of cloacal temperature in broiler chickens administered with graded levels of Bactofort® during the cold-dry (harmattan) season

ABSTRACT The study evaluated the effects of graded levels of Bactofort® on cloacal temperature fluctuations in broiler chickens during the cold–dry season. Complete randomised sampling was used to assign 225 broiler chicks into 5 groups with 3 replicates. The broiler chicks from Group I were fed a basal diet without Bactofort® supplementation, Group II 0.25 g of Bactofort® per kg of feed, Group III 0.35 g of Bactofort® per kg of feed, Group IV 0.45 g of Bactofort® per kg of feed and Group V were fed 0.55 g of Bactofort® per kg of feed. Beginning from day old, the treatment groups were fed with Bactofort® supplementation daily for 6 weeks. Dry-bulb temperature (DBT), relative humidity (RH) and temperature–humidity index (THI) inside the pen and cloacal temperature of each broiler chick were obtained hourly over a 12-h period from 06:00 to 18:00 h (GMT + 1), on days 28 and 42 of the study. Mean values of DBT (32.00 ± 0.42°C), THI (29.55 ± 0.60) and RH (43.27 ± 0.79%) obtained inside the poultry house were outside the thermoneutral zone for broiler chickens, and suggestive of thermal stress. The administration of Bactofort® in the treatment groups decreased the mean and amplitude and increased the robustness of cloacal temperature on days 28 and 42. Overall, the mean of cloacal temperature in the control group (42.00 ± 0.20°C) was higher (P < 0.0001) than those of the Bactofort®-treated groups at the dosages of 0.25 g/kg (41.06 ± 0.15°C), 0.35 g/kg (40.94 ± 0.10°C), 0.45 g/kg (40.92 ± 0.08°C) and 0.55 g/kg (40.80 ± 0.09°C). In conclusion, Bactofort® administration stabilised cloacal temperature of broiler chicken on days 28 and 42 by decreasing its values. The use of the probiotic may be beneficial in modulating diurnal rhythm of cloacal temperature and reducing adverse effects of thermal stress on broiler chickens.

Daily rhythms of cloacal temperature in broiler chickens of different age groups administered with zinc gluconate and probiotic during the hot-dry season

The aim of the experiment was to evaluate effects of zinc gluconate (ZnGlu) and probiotic administration on the daily rhythm of cloacal temperature (t cloacal) in broiler chickens of different age groups during the hot‐dry season. One‐day‐old broiler chicks (n = 60) were divided into groups I–IV of 15 chicks per group, and treated for 35 days: Group I (control) was given deionized water; Group II, ZnGlu (50 mg/kg); Group III, probiotic (4.125 × 106 cfu/100 mL), and Group IV, ZnGlu (50 mg/kg) + probiotic (4.125 × 106 cfu/100 mL). Air dry‐bulb temperature (t db), relative humidity (RH), and temperature‐humidity index (THI) inside the pen, and t cloacal of each broiler chick were obtained bihourly over a 24‐h period; on days 21, 28, and 35 of the study. Values of tdb (32.10 ± 0.49°C), RH (49.94 ± 1.91%), and THI (38.85 ± 0.42) obtained were outside the thermoneutral zone for broiler chickens, and suggested that the birds were subjected to heat stress. Application of the periodic model showed disruption of daily rhythm of t cloacal in broilers on day 21, which was synchronized by probiotic administration. The administration of probiotics or ZnGlu + probiotics to a greater extent decreased the mesor and amplitude, delayed the acrophases of t cloacal in broilers, especially at day 35, as compared to the controls. Overall, the t cloacal values in broiler chickens administered with probiotic alone (41.25 ± 0.05°C) and ZnGlu + probiotic (41.52 ± 0.05°C) were lower (P < 0.001) than that of the controls (41.94 ± 0.06°C). In conclusion, probiotic alone synchronized t cloacal of the birds at day 21, and, in addition, decreased t cloacal response most, followed by its coadministration with ZnGlu, the antioxidants may be beneficial in modulating daily rhythmicity of tcloacal and alleviating adverse effects of heat stress on broiler chickens during the hot‐dry season.

Depression of leukocyte protein synthesis, immune function and growth performance induced by high environmental temperature in broiler chickens.

In tropical and semitropical regions, raising broiler chickens out of their thermal comfort zone can cause an added economic loss in the poultry industry. The cause for the deleterious effects on immunity and growth performance of broilers under high environmental temperatures is still poorly understood. Therefore, the aim of the current investigation was to evaluate the effect of heat stress on leukocytes protein synthesis and immune function as a possible direct cause of low performance in broiler chickens under such condition. In this study, 300 one-day-old male broiler chicks (Cobb500™) were randomly assigned into 2 groups with 5 replicates of 30 chicks each. From 21 to 42days of age, one group was exposed to non-stressed condition at 24°C and 50% relative humidity (control group), while the other group was exposed to heat stress at 35°C and 50% relative humidity (HS group). At 42days of age, blood samples were collected from each group to evaluate stress indicators, immune function, and leukocytes protein synthesis. Production performance was also recorded. Noteworthy, protein synthesis in leukocytes was significantly (P<0.05) inhibited in HS group by 38% compared to control group. In contrast, the phosphorylation level on threonine 56 site (Thr56) of eukaryotic elongation factor (eEF2), which indicates the suppression of protein translation process through altering the protein elongation phase, was significantly threefold higher in HS group than in control (P<0.05). In addition, an increase in stress indicators was markedly (P<0.05) presented in the HS birds by twofold increase in heterophil/lymphocyte (H/L) ratio and threefold increase in plasma corticosterone level compared to control. Furthermore, the immune function was significantly (P<0.05) suppressed in HS birds than control (0.99 vs. 1.88mg/mL plasma IgG, 89.2 vs. 148.0μg/mL plasma IgM, 4.80 vs. 7.20 antibody titer against SRBC, and 1.38 vs. 3.39 stimulation index of lymphocyte proliferation in HS vs. control group, respectively). Moreover, results on the broiler performance indicate that HS birds had a significant (P<0.05) lower body weight gain by 58%, lower feed consumption by 39%, higher conversion ratio by 27%, and higher mortality by more than three times, compared to control birds. In conclusion, our results demonstrate that the inhibition of leukocyte protein synthesis through increasing the level of eEF2 Thr56 phosphorylation may play a key role in the observed decrease in immune function and growth performance with the high mortality rate encountered in broiler chickens under heat stress environment.

Validation of an intramuscularly-implanted microchip and a surface infrared thermometer to estimate core body temperature in broiler chickens exposed to heat stress

Heat stress in poultry is associated with an increased core body temperature (CBT) which can be fatal. Methods of estimating CBT range from the minimally invasive method of inserting a digital thermometer into the cloaca of the bird, to the implantation of a temperature recording device (e.g. a data logger) in the peritoneal cavity, a method which gives the most accurate measure of CBT but may be considered invasive. To validate the use of less invasive alternatives to assess CBT in broiler (meat type) chickens using injectable devices, 12 birds were subject to surgery to implant a data logger deep in the body cavity and a microchip in the breast muscle. The birds were then placed in floor pens with an additional 36 birds and subsequently subjected to one of four simulated heat stress conditions over a 3-day period. Measurements of body temperature were collected at intervals from the data logger and microchip (CBT and IM-chip, respectively) along with taken under the wing, feet, comb and cloaca using an infrared thermometer. Changes in body temperature were calculated as the ΔT between pre heat stress and end of 3h heat stress each day. There was no relationship between CBT and IM-chip, but there was a significant correlation between ΔCBT and ΔIM-chip (R=0.71, P<0.05) during the heat stress. SBT measured under the wing correlated with CBT (R=0.71, P<0.05). Collectively these data confirm the suitability of intramuscularly-implanted microchip and strategically-positioned infrared thermometers to monitor CBT in birds exposed to heat stress, thereby replacing the invasive surgery and associated side-effects of deep body-implanted data loggers for the benefit of animal welfare.

Effects of supplementation of betaine hydrochloride on physiological performances of broilers exposed to thermal stress

Betaine has the potential to spare methionine and choline as methyl-group donors, and is thought to improve broiler performance under conditions of stress. An experiment was conducted to ascertain the effects of supplemental betaine on performances and physiological responses of broilers exposed continuously to thermal stress. Male broilers (n=128, divided into four groups, with eight replicate cages in a group) received diets containing suboptimal levels of methionine and metabolizable energy and supplemented with 1.3 g/kg and 2 g/kg betaine hydrochloride from day 1 to 38. The positive control (PC) did not contain supplemental betaine, and the negative control (NC), to which betaine was added, was deficient in methionine and energy and devoid of added choline. The experiment included assessment of growth, feed-conversion ratio, rectal temperature and respiration rates, and assay of blood hormones and metabolites. Betaine at both the levels of inclusion improved live weight and feed intake over the PC and the NC groups. Rectal temperature and respiration rates were also lower in the betaine-supplemented groups, indicating a sequestering effect of betaine on metabolic rates of thermally stressed broilers. Carcass yield was unaffected. Betaine-supplemented groups had better thyroid activity than the NC and PC groups of birds. Based on this study, it was inferred that in tropical countries betaine may be effectively used to ameliorate the negative impact of high ambient temperature in broiler chickens. The findings also suggest that at an appropriate dose, betaine may spare some quantity of dl-methionine and dietary energy to support the growth process of heat-stressed broilers. However, further studies are warranted to assign a definite methionine and energy matrix to supplemental betaine that can be used in broiler diets without inviting any risk of drop in production. betaine, broiler chickens, heat stress, performance, physiological responses

Telmisartan Protect Broiler Chickens from Pulmonary Arterial Remodeling Induced by Low Ambient Temperature

Objective: Renin-angiotensin system is associated with many vascular diseases. This study aims to explore the protective effect of telmisartan, Angiotensin type 1 receptor blocker, on pulmonary arterial remodeling induced by low ambient temperature in broiler chickens. Methods: Ninety chickens were randomly divided into 3 groups (n=30), including control group, low temperature group and telmisartan group. Chickens in low temperature group and telmisartan group were exposed to low ambient temperature from 14 days of age until 45 days of age; chickens in telmisartan group were gavaged with telmisartan 5 mg/kg once daily for thirty days. The pulmonary arterial systolic pressure was measured with right catheterization method. Wet lung weight index and right ventricular hypertrophy index were evaluated. Small pulmonary artery wall thickness and elastic fibers was determined respectively by H-E staining and Weight staining. Proliferating Cell Nuclear Antigen (PCNA)-positive cells were determined by Immunohistochemical staining. Results: It showed that pulmonary arterial systolic pressure, wet lung weight index and right ventricular hypertrophy index, small pulmonary artery wall thickness, elastic fibers and PCNA expression increased significantly in Low temperature group compared with control group and telmisartan group. Conclusion: Telmisartan can protect broiler chickens from pulmonary arterial remodeling induced by low ambient temperature

Imidapril inhibits right ventricular remodeling induced by low ambient temperature in broiler chickens

This study explored the effect of imidapril on the right ventricular remodeling induced by low ambient temperature in broiler chickens. Twenty-four broiler chickens were randomly divided into 3 groups (n = 8), including the control group, low temperature group, and imidapril group. Chickens in the control group were raised at normal temperature, whereas chickens in the low temperature group and imidapril group were exposed to low ambient temperature (12 to 18°C) from 14 d of age until 45 d of age. At the same time, chickens in the imidapril group were gavaged with imidapril at 3 mg/kg once daily for 30 d. The thickness of the right ventricular wall was observed with echocardiography. The BW and wet lung weight as well as weight of right and left ventricles and ventricular septum were measured. Both wet lung weight index and right ventricular hypertrophy index were calculated. Pulmonary arterial systolic pressure was assessed according to echocardiography. The expression of ACE and ACE2 mRNA in the right ventricular myocardial tissue was quantified by real-time PCR. Proliferating cell nuclear antigen-positive cells were detected by immunohistostaining. The concentration of angiotensin (Ang) II and Ang (1-7) in the right ventricular myocardial tissue was measured with ELISA. The results showed that right ventricular hypertrophy index, wet lung weight index, pulmonary arterial systolic pressure, expression of ACE mRNA in the right ventricular tissue, Ang II concentration, and the thickness of the right ventricular wall in the low temperature group increased significantly compared with those in the control group and imidapril group. The ACE2 mRNA expression increased 36%, whereas Ang (1-7) concentration decreased significantly in the low temperature group compared with that in the control group and imidapril group. In conclusion, imidapril inhibits right ventricular remodeling induced by low ambient temperature in broiler chickens.

Imidapril provides a protective effect on pulmonary hypertension induced by low ambient temperature in broiler chickens

The objective of this article is to explore the role of imidapril on pulmonary hypertension induced by low ambient temperature in broiler chickens. Ninety chickens were randomly divided into three groups (n = 30): a control group, a low-temperature group and an imidapril group. Chickens in the low-temperature group and imidapril group were exposed to low ambient temperature from 14 days of age until 45 days of age; chickens in the imidapril group were gavaged with imidapril 3 mg/kg once daily for 30 days. The pulmonary arterial pressure, main pulmonary arterial diameter and pulmonary arterial wall thickness were measured, and lung tissue ACE, ACE2 mRNA expression, proliferating cell nuclear antigen (PCNA)-positive cells and Ang II, Ang (1-7) concentration were evaluated. The pulmonary arterial pressure was higher, the main pulmonary arterial diameter was wider and the pulmonary arterial wall was thicker in the low-temperature group than those in the control group and the imidapril group. ACE mRNA and PCNA-positive cells increased significantly in the low-temperature group compared with the control group and imidapril group; lung tissue Ang II concentration in the low-temperature group was higher, but Ang (1-7) content was lower than that in the control group and imidapril group. Imidapril provides a protective effect on pulmonary hypertension induced by low ambient temperature in broiler chickens.

FREQÜÊNCIA RESPIRATÓRIA E TEMPERATURA CLOACAL EM FRANGOS DE CORTE SUBMETIDOS À TEMPERATURA AMBIENTE CÍCLICA ELEVADA

Este estudo objetivou verificar os efeitos da temperatura ambiente cíclica elevada sobre afreqüência respiratória e temperatura cloacal em frangos de corte. Setenta pintos da linhagem Avian, machosforam alojados em baterias de gaiolas de julho a agosto de 2004 e divididos em dois grupos. O primeiro foisubmetido diariamente, durante uma hora, à temperatura ambiente elevada do primeiro até o 42º dia de idade(grupo ST). O segundo mantido em temperatura de conforto térmico (grupo TN). Analisou-se semanalmente afreqüência respiratória e temperatura cloacal, de dez aves do grupo ST, antes e após o estresse por calor. Nogrupo TN, estes parâmetros foram avaliados entre 12 e 13 horas. O delineamento foi feito em parcelasubdividida “Split-Plot” no tempo.Oefeito temperatura ambiente foi considerado parcela, enquanto que o efeitoidade, subparcela. Os dados foram analisados pela análise de variância e as médias comparadas pelo teste deTukey a 5%. As aves ST e TN apresentaram aumento da temperatura cloacal com a idade. No grupo TN, afreqüência respiratória reduziu com a idade. As aves do ST tiveram aumento na freqüência respiratória etemperatura cloacal depois do estresse pelo calor. Assim, a temperatura corporal aumenta com a idade dofrango, independentemente da temperatura ambiente, e a freqüência respiratória reduz com a idade para asaves em termoneutralidade. Frangos de corte submetidos à temperatura ambiente cíclica elevada apresentamaumento na freqüência respiratória e na temperatura cloacal.

Abdominal skin temperature variation in healthy broiler chickens as determined by thermography

Abdominal skin temperature of healthy broiler chickens was determined by thermography to estimate the normal range of between- and within-bird temperature variation. Effects of potential confounding factors, such as bird's contention duration, abdominal side, age, and time of day, were also estimated. Mean skin temperature was estimated from thermogram pictures by computer image analysis of a predetermined abdominal area. Results demonstrated that skin temperature was not significantly affected by contention duration. However, skin temperature was higher on the right abdominal side in younger birds and at 1200 h. Between- and within-bird variation in healthy birds was small (< 0.5 degrees C) when age, abdominal side, and time of day were taken into account. This work suggests that skin temperature measurement using thermography can be adapted for the study of skin temperature in broiler chickens.