Hsp70 Genotypes and Heat Tolerance of Commercial and Native Chickens Reared in Hot and Humid Conditions

Abstract

Heat tolerance in poultry production was obtained attention due to the need for genetic lines that can withstand climate changes. This study aimed at investigating heat tolerance in commercial and native broiler genetics, as well as the physiological and growth performance responses of HSP70 genotypes submitted to heat stress. In Experiment I, heterophil:lymphocyte (H:L) ratio, as an indicator of heat tolerance, was compared between commercial broilers (n = 100) and Thai native chickens (n = 100). Growing chickens (with similar initial weight) of each genetic strain were randomly divided into two groups: 1) thermoneutral environment (26 o C ± 2 o C) and 2) heat stress (36 o C ± 2 o C). The results showed that native chickens originating from a tropical environment presented lower H:L ratio and mortality rate compared with commercial broilers. In Experiment II, HSP70 genotypes were compared. PCR-RFLP was applied to identify the genotypes (C1C1, n = 38; C1C2, n = 38; and C2C2, n = 28). Ten-week-old chickens of each genotype were evaluated in the same environments described in Experiment I. Heat-stress indicators -respiratory rate (RR), cloacal temperature (CT), packed cell volume (PCV), and average daily gain (ADG) -were measured for three weeks. The significant difference in PCV indicated that C2C2 chickens were less tolerant to heat stress compared to other genotypes. The RR, CT, and ADG were not significantly different among all genotypes. Since the C2C2 genotype was shown to be sensitive to heat stress, C1C1 and C1C2 could be used as markers for heat-tolerant genetic strains of Thai indigenous chickens and hybrid commercial lines.

Effect of dietary nutmeg oil on heat‐stress tolerance‐related parameters in Korean native chicken reared under hot temperature

“…However, there was not such an action on H:L ratio of NO 500 group. Duangjinda, Tunim, Duangdaen, and Boonkum () reported that the H:L ratio was increased after week 1 of heat exposure in chickens but tended to recover to normal levels after 3 weeks of heat exposure because of homoeostasis. Although we only have data up to the end of week 6 of the feeding trial, the H:L ratio might also have been recovered in our chicks by homoeostasis.…”

“…However, there was not such an action on H:L ratio of NO 500 group. Duangjinda, Tunim, Duangdaen, and Boonkum (2017) reported that the H:L ratio was increased after week 1 of heat exposure in chickens but tended to recover to normal levels after 3 weeks of heat exposure because of homoeostasis.…”

Genetic Diversity of the Structure of HSP70 Gene in Kampung Unggul Balitbangtan (KUB), Walik, and Kate Walik Chickens

“…Three of the detected alleles (hsp70-1, hsp70-2, and hsp70-3) were associated with the nature of resistance to heat stress, and therefore, it's potential to be used as a candidate gene for heat stress (Mazzi et al, 2003). The results of this study have encouraged additional research in the other chickens: Indonesian local chicken (Tamzil et al, 2013a), Taiwanese local chicken (Liang et al, 2016), and Thailand local chicken (Duangjinda et al, 2017).…”

HSP70 And HSP90β Genes Polymorphism And Its Association With Thermotolerance In Fayoumi And Leghorn Chicken Breeds

“…Genotyping and allelic frequency variation of HSP70 gene by Liang et al, (2016) indicated that AA genotype has greater heat tolerance after acute heat stress in the indigenous Taiwanese chickens. Results of HSP70 gene genotyping by Duangjinda et al, (2017) using CfrI restriction enzyme also are indicated that C2C2 chickens were less tolerant to heat stress compared to other genotypes.…”

“…PCR primers of chickens HSP70 gene and HSP90β gene is described in table (1). Forward and reverse primers of HSP70 gene were used to amplify 360 bp from the beginning of the coding region and EaeI restriction enzyme was used for genotyping polymorphisms in this region as described by (Duangjinda et al, 2017). On the other hand, HSP90β gene Primers were used to amplify 498 bp from the 5' flanking region and exon 2 of this gene, and polymorphisms in this region was genotyped by using MspI restriction enzyme according to (Chen et al, 2013).…”