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Effect of Thermal Conditioning on the Production Performance of Different Strains of Chicken

S. Sivaramakrishnan A. V. Omprakash S. Ezhilvalavan K. G. Tirumurugaan A. Varun S. Naveenkumar
Vol 8(2), 291-298
DOI- http://dx.doi.org/10.5455/ijlr.20170808071018

Total of 360 chicken (90 chicken from each strain) were randomly assigned in to three treatment with three replicates and each replicate contain 30 chicks. The first treatment served as a control group where birds reared under ambient temperature, birds in second treatment were exposed to heat stress at 37oC for 4 hours and birds in third treatment were exposed to 39oC for 2 hours from day old to 14 days and 29 to 42 days of age, apart from exposure period birds were reared at ambient temperature. The results showed a significantly (P<0.05) decreased body weight, body weight gain and feed consumption at 6th week of age in thermal conditioned birds, irrespective of strains. However, at the end of 12th week broiler strains (Nandanam Broiler-3 and Naked Neck) had significantly (P<0.05) increased body weight, body weight gain and feed consumption. It was concluded that during thermal conditioning body weight was decreased, whereas at later days compensatory growth occurred to improve the weight at marketing age.


Keywords : Body Weight Feed Consumption Feed Efficiency and Compensatory Growth Thermal Conditioning Weight Gain

Introduction

Poultry is a promising and emerging sector for poverty alleviation as well as a cheapest animal protein source in developing countries. However, various factors affect the productivity of poultry in the tropical and subtropical countries. Among them, stress due to high environmental temperature is widely recognized as one of the primary problems in poultry production under tropical and subtropical climates (Cahaner et al., 2008). In poultry, high temperature beyond the thermoneutral zone (18-24oC), especially when coupled with high humidity causes environmental heat stress. Chicken is the most vulnerable species to heat stress when compared with other domestic animals because of feather covering and the lack of sweat glands and their higher body temperature (Sahin et al., 2009). Every year in Tamil Nadu an increase of 0.03oC has been observed due to global warming (Rathore et al., 2013).  In summer months, the temperature has reached up to 45oC and this higher temperature leads to mortality upto 20 per cent because of less thermo tolerance of birds.

Birds were more prone to heat stress due to the less thermotolerance. Thermo tolerance defined as the ability of the birds to maintain the expression of their inherited functional potential when raised under hot climatic conditions. Induction of thermo-tolerance can potentially be incorporated into developing thermoregulation mechanisms. Repeated short period of thermal conditioning at the early stage of chicken life improves the ability of chicken to cope with scorching temperature in later life and increased body weight (El-Azim, 2012). Therefore, the present study was designed to study the effect of different thermal conditioning on production performances of Aseel, Nandanam Broiler – 3, Nandanam Chicken – 4 and Nacked Neck.

Material and Methods

The experiment was carried out at Poultry Research Station, Tamil Nadu Veterinary and Animal Sciences University, Chennai -600 051. Experimental chicken obtained from the Poultry Research Station Hatchery. For this experiment, four different strains were utilized namely Aseel (Native chicken), Nandanam Chicken – 4 (Synthetic layer, developed by TANUVAS), Nandanam Broiler – 3 (Broiler strain, developed by TANUVAS) and Naked Neck (Broiler strain). A total of 360 chickens (90 chicks from each strain) were weighed and wing banded and randomly assigned as the three treatment groups with three replicates. Birds in treatment T1 served as the control group reared under ambient temperature for a period of 12 weeks. Birds in treatment T2 chicken were exposed to thermal stress at 37oC for 4 hours and birds in treatment T3 chicken were exposed to thermal stress at 39oC for 2 hours. Birds were exposed to thermal conditioning during 0-14 days of age and 29-42 days of age, apart from the exposure periods birds reared under ambient temperature. During the heat exposure period ad libitum feed and water were provided.

All the chicks vaccinated against RDVF1, IBD, LaSota, and RDVK respectively at 7,14,28,56 days of age. At bi-weekly interval body weight (BW) and feed consumption (FC) were recorded. From these data obtained, body weight gain (BWG) and feed efficiency (FE) were calculated. The data were analysed by one way ANOVA using the SPSS-20 software. Treatment means that were significant, further subjected to Duncan’s post-hoc test (Duncan, 1955).

Results and Discussion

Effect of Thermal Conditioning on Body Weight and Body Weight Gain

The effects of thermal conditioning on body weight and body weight gain (LSM±SE) from 0 to 12 weeks of age in different chicken strains are presented in Table 1 and Table 2.

Table 1: Effect of thermal conditioning on cumulative bi-weekly body weight (g) from 0 to 84 days of age in different chicken strains (LSM ± SE)

Chicken strains Treatment 14th day 28th day 42nd day 56th day 70th day 84th day 14th day
(n=30) (n=28) (n=28) (n=26) (n=26) (n=26) (n=30)
Aseel T1-AT 36.75 ± 0.34 83.34 ± 1.32 222.19 ± 3.41 394.36a ± 5.84 590.63 ± 7.27 794.27 ± 10.13 1026.25 ± 13.65
T2-37oC 36.11 ± 0.34 86.23 ± 1.32 221.22 ± 3.41 379.57ab ± 5.84 582.09 ± 7.27 785.26 ± 10.13 1026.78 ± 13.65
T3-39oC 36.99 ± 0.34 85.88 ± 1.32 219.93 ± 3.41 370.99b ± 5.84 579.38 ± 7.27 780.58 ± 10.13 1017.68 ± 13.65
F value 0.6 0.55 1.73 3.22 0.34 0.51 0.124
Significance NS NS NS * NS NS NS
Nandanam Chicken – 4 T1-AT 39.72 ± 0.36 89.22 ± 1.33 209.36 ± 3.40 386.53a ± 5.82 583.08 ± 7.25 785.06 ± 10.12 1009.08 ± 13.64
T2-37oC 39.88 ± 0.36 88.23 ± 1.33 208.26 ± 3.40 366.71ab ± 5.82 575.73 ± 7.25 780.01 ± 10.12 1008.57 ± 13.64
T3-39oC 39.91 ± 0.36 87.11 ± 1.33 207.31 ± 3.40 358.69b ± 5.82 568.71 ± 7.25 773.38 ± 10.12 997.67 ± 13.64
F value 0.08 0.27 1.77 3.32 0.94 0.13 0.24
Significance NS NS NS * NS NS NS
Nandanam Broiler – 3 T1-AT 42.01 ± 0.43 141.71 ± 2.31 413.36 ± 6.14 803.34a ± 10.18 1280.16 ± 15.89 1712.92 ± 19.89 2051.58b ± 21.68
T2-37oC 42.15 ± 0.43 142.39 ± 2.31 411.59 ± 6.14 773.03b ± 10.18 1270.50 ± 15.89 1730.88 ± 19.89 2112.92a ± 21.68
T3-39oC 42.27 ± 0.43 144.63 ± 2.31 410.50 ± 6.14 764.91b ± 10.18 1260.58 ± 15.89 1705.35 ± 19.89 2041.50b ± 21.68
F value 0.05 0.25 0.19 3.73 0.55 0.76 3.61
Significance NS NS NS * NS *
Naked Neck T1-AT 41.61 ± 0.42 154.30 ± 2.32 522.72 ± 6.73 1003.54a ± 11.29 1526.84 ± 16.37 2140.68 ± 22.47 2439.92b ± 24.53
T2-37oC 41.58 ± 0.42 155.21 ± 2.32 520.89 ± 6.73 978.07b ± 11.29 1518.26 ± 16.37 2161.69 ± 22.47 2497.81a ± 24.53
T3-39oC 41.43 ± 0.42 156.63 ± 2.32 519.80 ± 6.73 976.96b ± 11.29 1513.73 ± 16.37 2136.97 ± 22.47 2437.08b ± 24.53
F value 0.02 0.1 1.72 4.72 0.21 0.33 3.71
Significance NS NS NS * NS NS *

a, b Means with different superscript within the column of each chicken strains are significant. *=significant (P<0.05). NS=Non-significant, T1 – Ambient temperature, T2 – 37oC Thermal stress for 4 hours, T3 – 39oC Thermal stress for 2 hours

It was observed that early thermal conditioning at 0-14 days of age at both 37oC for 4 hours and 39oC for 2 hours showed non-significant difference with respect to body weight and body weight gain in different strains. Whereas, at 2nd thermal conditioning (29-42 days) observed that a significantly (P<0.05) decreased body weight and body weight gain among all the treatment groups. Birds that were conditioned at 39oC showed decreased body weight and body weight gain, compared to 37oC conditioned group and control group. Same trend was followed during 56 and 70 days of age with respect to body weight and body weight gain irrespective of strains. The present findings of this study was in agreement with the previous studies of Amrutkar (2012) and Fernandes et al. (2013) who stated that, there was a significantly decreased body weight upon the heat stress during early age of life.

Table 2: Effect of thermal conditioning on cumulative bi-weekly body weight gain (g) from 0 to 84 days of age in different chicken strains (LSM ± SE)

Chicken strains Treatment 14th day 28th day 42nd day 56th day 70th day 84th day
(n=30) (n=28) (n=28) (n=26) (n=26) (n=26)
Aseel T1-AT 46.44 ± 1.30 189.79 ± 3.40 357.56a ± 5.82 553.82 ± 7.25 757.46 ± 10.12 989.44 ± 13.64
T2-37oC 50.12 ± 1.33 185.24 ± 3.39 343.59ab ± 5.81 546.19 ± 7.25 749.36 ± 10.12 990.88 ± 13.64
T3-39oC 48.83 ± 1.32 179.34 ± 3.39 333.89b ± 5.81 542.14 ± 7.24 743.34 ± 10.12 980.44 ± 13.64
F value 0.85 1.83 3.14 0.35 0.53 0.15
Significance NS NS * NS NS NS
Nandanam Chicken – 4 T1-AT 49.43 ± 1.33 170.46 ± 3.39 346.63a ± 5.80 543.30 ± 7.24 745.28 ± 10.11 969.30 ± 13.63
T2-37oC 48.35 ± 1.33 164.30 ± 3.38 326.76ab ± 5.79 535.77 ± 7.24 740.05 ± 10.11 968.61 ± 13.63
T3-39oC 47.20 ± 1.32 160.37 ± 3.39 318.73b ± 5.79 528.63 ± 7.24 733.30 ± 10.11 957.60 ± 13.64
F value 0.33 1.88 3.4 0.98 0.14 0.25
Significance NS NS * NS NS NS
Nandanam Broiler -3 T1-AT 99.70 ± 2.32 374.19 ± 6.05 761.17a ± 10.16 1237.57 ± 15.87 1670.15 ± 19.88 2008.82b ± 21.67
T2-37oC 100.24 ± 2.31 369.36 ± 6.05 730.80b ± 10.15 1228.50 ± 15.88 1688.89 ± 19.88 2070.93a ± 21.68
T3-39oC 102.36 ± 2.30 368.20 ± 6.05 722.62b ± 10.15 1217.94 ± 15.87 1662.71 ± 19.88 1998.87b ± 21.67
F value 0.22 0.2 3.84 0.55 0.8 3.71
Significance NS NS * NS NS *
Naked Neck T1-AT 112.70 ± 2.33 481.21 ± 6.71 962.03a ± 11.28 1484.82 ± 16.35 2098.66 ± 22.46 2397.90b ± 24.52
T2-37oC 113.63 ± 2.31 478.88 ± 6.72 936.06b ± 11.27 1476.53 ± 16.35 2119.96 ± 22.47 2456.08a ± 24.54
T3-39oC 116.21 ± 2.31 478.37 ± 6.72 935.54b ± 11.27 1470.83 ± 16.35 2094.87 ± 22.46 2395.18b ± 24.52
F value 0.11 0.22 3.39 0.13 0.45 3.65
Significance NS NS * NS NS *

a, b Means with different superscript within the same column of each chicken strains are significant. *=significant (P<0.05). NS=Non-significant, T1 – Ambient temperature, T2 – 37oC Thermal stress for 4 hours, T3 – 39oC Thermal stress for 2 hours

At the age of 84 days, Aseel and Nandanam chicken-4 showed non-significant difference with respect to body weight and body weight gain. However, there was a significant (P<0.05) difference noticed in broiler strains namely Nandanam broiler-3 and Naked neck, whereas the birds exposed at 37oC had higher body weight and body weight gain (2112.92; 2497.81 and 2070.93; 2456.08 g), when compared with 39oC conditioned birds (2041.50, 2437.08 and 1998.87, 2395.18 g) and control (2051.58; 2439.92 and 2008.82; 2397.90 g) birds respectively. These findings were in agreement with the previous studies of El-Azim (2012) and Gunal (2013) who reported that there was a higher body weight noticed in the heat stressed birds at later age. However, 39oC conditioned birds failed to increase the body weight, this observation was in accordance with Yahav and McMurtry, (2001) who concluded that higher temperature thermal conditioning had lower body weight compared to lower temperature thermal conditioning birds. Thermal conditioning resulted in growth retardation followed by an immediate compensatory growth at market age (Yahav and McMurty, 2001).

Effect of Thermal Conditioning on Feed Consumption

The effect of thermal conditioning on feed consumption (Mean±SE) from 0 to 84 days of age in different chicken strains is presented in Table 3.

 

Table 3: Effect of thermal conditioning on bi-weekly feed consumption (g) from 0 to 84 days of age in different chicken strains (Mean ± SE)

Chicken strains Treatment 0-14 days 15-28 days 29-42 days 43-56 days 57-70 days 71-84 days
(n=30) (n=28) (n=28) (n=26) (n=26) (n=26)
Aseel T1-AT 111.44 ± 0.65 375.28 ± 1.07 486.90a ± 2.87 640.85 ± 3.42 835.24 ± 4.50 961.02 ± 5.95
T2-37oC 113.60 ± 0.55 373.63 ± 1.29 482.33b ± 2.72 639.46 ± 389 834.39 ± 4.77 961.57 ± 5.73
T3-39oC 112.65 ± 0.65 372.57 ± 1.47 481.61b ± 2.26 638.70 ± 3.89 832.37 ± 4.70 959.43 ± 5.30
F value 3.06 1.13 8.92 2.02 0.56 2.42
Significance NS NS * NS NS NS
Nandanam Chicken – 4 T1-AT 123.35 ± 0.50 347.44 ± 1.34 460.93a ± 2.95 624.31 ± 3.00 708.37 ± 4.82 759.35 ± 5.93
T2-37oC 122.56 ± 0.77 344.17 ± 1.05 457.64b ± 2.92 622.52 ± 3.52 707.35 ± 4.98 760.90 ± 5.78
T3-39oC 121.63 ± 0.76 343.22 ± 1.16 456.39b ± 2.95 621.81 ± 3.58 705.81 ± 4.59 757.69 ± 5.72
F value 1.58 3.47 7.65 3.09 2.52 3.89
Significance NS NS * NS NS NS
Nandanam Broiler – 3 T1-AT 205.57 ± 0.51 610.80 ± 1.43 802.85a ± 2.44 1109.40 ± 3.21 1505.21 ± 4.65 1975.83b ± 5.82
T2-37oC 206.65 ± 0.56 608.12 ± 1.69 797.39b ± 2.13 1108.11 ± 3.81 1507.89 ± 4.72 1981.27a ± 5.55
T3-39oC 207.49 ± 0.68 607.34 ± 1.21 795.08b ± 2.17 1106.98 ± 3.89 1503.77 ± 4.17 1974.75c ± 5.36
F value 2.68 1.64 8.83 1.51 4.17 6.92
Significance NS NS * NS NS *
Naked Neck T1-AT 203.26 ± 0.67 606.17 ± 1.17 851.79a ± 2.80 1331.56 ± 3.48 1877.02 ± 4.90 2220.26b ± 5.77
T2-37oC 203.79 ± 0.57 605.69 ± 1.20 847.21b ± 2.53 1330.06 ± 3.97 1878.26 ± 4.96 2226.62a ± 5.68
T3-39oC 204.67 ± 0.65 604.82 ± 1.31 846.07b ± 2.81 1329.81 ± 3.37 1876.42 ± 4.34 2219.34b ± 5.95
F value 1.72 0.31 7.42 2.06 1.42 6.53
Significance NS NS * NS NS *

   a, b, c Means with different superscript within same column of each chicken strains are significant. *=significant (P<0.05), NS=Non-significant,  T1 – Ambient temperature, T2 – 37oC Thermal stress for 4 hours, T3 – 39oC Thermal stress for 2 hours

It was observed that early thermal conditioning at 0-14 days of age at both 37oC for 4 hours and 39oC for 2 hours had no significant difference with respect to feed consumption among the different chicken strains, whereas at 2nd thermal conditioning (29-42 days), there was a significantly (P<0.05) decreased feed consumption among all the treatment groups. Birds conditioned at 39oC showed decreased feed consumption, compared to 37oC conditioned group and control group. The same trend was followed during 56 and 70 days of age with respect to feed consumption irrespective of strains. This present findings were in agreement with previous findings of Amrutkar et al. (2012), Hosseini et al. (2015) and Jahejo et al. (2016) who reported that there was a significantly decreased feed consumption among the various heat treatment groups. However, the present findings were in disagreement with the findings of El-Azim (2012) and Fernandes et al. (2013) who observed a non-significant difference with respect to feed consumption among various heat treatment groups. Heat stress stimulates the hypothalamic axis through increasing leptin and adiponectin levels and results in a reduced feed intake (Morera et al., 2012). Neurotransmitters such as serotonin (5-HT) and dopamine (DA) are known to play critical adaptive role in the stress response regulation. It is known that ghrelin (GHR) and 5-HT act on the hypothalamus and inhibit feed intake by stimulation of the 5-HTergic system or release of corticotrophin releasing factor in chickens (Najafi et al., 2015).

Similar trend was also noticed in 84 days of age especially in Aseel, Nandanam chicken-4 which was non-significant. However, there was a significant (P<0.05) difference noticed among the treatment groups especially in Nandanam broiler-3 and Naked neck, where in the birds exposed at 37oC had higher feed consumption (1981.27 and 2226.62 g), when compared with 39oC conditioned birds (1974.75 and 2219.34 g) and control (1975.83 and 2220.26 g) birds respectively. The present findings were in agreement with the previous findings of Yahav and McMurtry, (2001) who found that the birds were thermally conditioned for 24 hours had showed highest feed intake.

Effect of Thermal Conditioning on Feed Efficiency

The effect of thermal conditioning on feed efficiency (mean±SE) from 0 to 84 days of age in different chicken strains was presented in Table 4.

Table 4:  Effect of thermal conditioning on cumulative bi-weekly feed efficiency (Mean ± SE) from 0 to 84 days of age in different chicken strains

Chicken strains Treatment 14th day 28th day 42nd day 56th day 70th day 84th day
(n=30) (n=28) (n=28) (n=26) (n=26) (n=26)
Aseel T1-AT 1.32 ± 0.01 2.18 ± 0.01 2.47a ± 0.01 2.73a ± 0.01 3.08a ± 0.02 3.32 ± 0.01
T2-37oC 1.32 ± 0.01 2.20 ± 0.01 2.55b ± 0.02 2.76b ± 0.02 3.11b ± 0.01 3.32 ± 0.02
T3-39oC 1.31 ± 0.02 2.20± 0.02 2.61c ± 0.03 2.77c ± 0.01 3.13c ± 0.02 3.34 ± 0.02
F value 3.85 1.63 386.88 163.16 216.02 2.16
Significance NS NS ** ** ** NS
Nandanam Chicken – 4 T1-AT 1.38 ± 0.01 2.24 ± 0.01 2.42a ± 0.01 2.67a ± 0.01 2.88a ± 0.01 3.00 ± 0.02
T2-37oC 1.39 ± 0.02 2.24 ± 0.01 2.53b ± 0.01 2.69b ± 0.02 2.89b ± 0.02 2.99 ± 0.02
T3-39oC 1.39 ± 0.01 2.24 ± 0.02 2.57b ± 0.01 2.71c ± 0.01 2.91c ± 0.02 3.01 ± 0.01
F value 4.1 1.89 155.64 366.26 134.74 3.86
Significance NS NS ** ** ** NS
Nandanam Broiler – 3 T1-AT 1.45 ± 0.01 1.98 ± 0.01 2.02a ± 0.01 2.13a ± 0.02 2.47b ± 0.01 3.03b ± 0.01
T2-37oC 1.45 ± 0.02 1.98 ± 0.02 2.09b ± 0.02 2.14b ± 0.01 2.45a ± 0.02 2.94a ± 0.04
T3-39oC 1.45 ± 0.02 1.98 ± 0.02 2.11c ± 0.03 2.16c ± 0.01 2.48b ± 0.01 3.04b ± 0.02
F value 3.45 4.27 153.8 131.15 200.45 192.67
Significance NS NS ** ** ** **
Naked Neck T1-AT 1.32 ± 0.01 1.55 ± 0.01 1.65a ± 0.01 1.96a ± 0.01 2.28b ± 0.01 2.90b ± 0.01
T2-37oC 1.31 ± 0.02 1.55 ± 0.02 1.70b ± 0.02 1.97b ± 0.02 2.26a ± 0.02 2.83a ± 0.03
T3-39oC 1.31 ± 0.01 1.56 ± 0.01 1.70b ± 0.02 1.97b ± 0.01 2.27b ± 0.02 2.91b ± 0.02
F value 2.65 2.9 138.43 11.56 35.37 212.31
Significance NS NS ** ** ** **

a, b, c Means with different superscript within same column of each chicken strains are significant.. **=Highly significant (P<0.01), NS=Non-significant, T1 – Ambient temperature, T2 – 37oC Thermal stress for 4 hours, T3 – 39oC Thermal stress for 2 hours

It was observed that early thermal conditioning at 0-14 days of age at both 37oC for 4 hours and 39oC for 2 hours had non-significant difference with respect to feed efficiency among different strains. Whereas at 2nd thermal conditioning (29-42 days), there was a significantly (P<0.01) poor feed efficiency noticed among all the treatment groups. Birds conditioned at 39oC showed poor feed efficiency, compared to 37oC conditioned group and control group. The same trend was followed during 56 and 70 days of age with respect to feed efficiency with irrespective of strains. This present findings were in agreement with previous studies of Al-Fataftah et al. (2007), Hosseini et al. (2015) and Jahejo et al. (2016) who observed that the heat stressed birds had poor feed efficiency compared to the control birds.

At the end of experimental period (84th day) Aseel and Nandanam chicken-4 showed non-significant (P>0.05) difference. Whereas in broiler strains namely Nandanam broiler-3 and Naked neck showed significant (P<0.01) difference among the treatment groups, especially 37oC conditioned birds had better feed efficiency (2.94 and 2.83), when compared with 39oC conditioned birds (3.04 and 2.91) and control (3.03 and 2.90) birds. This results were in agreement with previous findings of Attou et al. (2011) who observed that heat conditioned birds had better feed efficiency.

Conclusion

From the results of the present study, it was concluded that broiler chicken strains conditioned at 37oC showed significant increase in the body weight and better feed efficiency as compared to the birds that were conditioned at 39oC and control birds. Increase in body weight at market age might be due to compensatory growth occur in broiler strains such as Nandanam broiler-3 and Naked neck.

References

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