Effects of acute heat stress on intestinal microbiota in grow‐finishing pigs, and associations with feed intake and serum profile

Abstract

Aims This study was conducted to assess the effects of acute heat stress (HS) on intestinal microbiota, and the associations with the changes in feed intake (FI) and serum profile. Methods and Results Twenty four individually housed pigs (Duroc × Large White × Landrace, 30 ± 1 kg body weight) were randomly assigned to receive one of three treatments (8 pigs/treatment): (i) thermal neutral (TN) conditions (25 ± 1°C), (ii) HS conditions (35 ± 1°C), (iii) pair‐feeding (PF) with HS under TN conditions. After 24‐h treatment, pigs were monitored to assess FI, and samples of serum and faeces were collected to investigate serum profile, microbial composition and short chain fatty acids (SCFAs). The results showed that HS decreased (P < 0·05) FI compared with the TN group. Compared with TN group, HS changed the serum profile by affecting biochemical parameters and hormones related with energy metabolism and stress response; immune indicators were also altered in HS group. Most of changes in serum profile were independent of FI reduction. Additionally, HS shifted the diversity and composition of faecal microbial community by increasing (P < 0·05) Proteobacteria and decreasing (P < 0·05) Bacteroidetes. Moreover, HS decreased (P < 0·05) the concentrations of propionate, butyrate, valerate, iso‐valerate and total SCFAs in faeces in an FI‐independent manner. Furthermore, the Spearman correlation analysis implied that changes of serum profile have potential correlation with alterations of faecal microbiota and their SCFAs metabolites in acute HS‐treated grow‐finishing pigs. Conclusions Metabolism disorders caused by 24‐h acute HS associated with changes of faecal microbiota and their SCFAs metabolites in an FI‐independent manner in grow‐finishing pigs. Significance and Impact of the Study These results give us a new insight of the intestinal damage caused by acute HS and the underlying mechanisms.

Heat stress on microbiota composition, barrier integrity, and nutrient transport in gut, production performance, and its amelioration in farm animals

“…Relatedly, specific richness was greater in hot climatic conditions than in the temperate climatic conditions in feces of pigs [20]. In other studies, HS did not show alterations of alpha-diversity such as Shannon index of the gut microbiota in cecum of laying hens [21], cecum of broiler chickens except phylogenetic diversity [22], ileum and jejunum of ducks [23], feces of pigs [24,25] (%) are presented depending upon the availability of the information in the literature. THI, temperature humidity index.…”

“…Although alpha-diversity of gut microbiota is minimally affected by HS, gut microbiota at the community level is usually influenced by HS, especially due to changes of the microbiota at the lower taxonomic levels such as family and genus levels. The principal coordinate analysis based on beta-diversity of the overall microbial community composition suggests that microbiota in ileum [19] and cecum [22] [25] also resulted in two distinct microbiota communities. But, HS effect has differential impacts on the microbiota communities in the different segments of guts.…”

“…In Hanoo steers, HS (15 °C vs. 35 °C) caused a change in microbial community composition in the rumen on day 6 of heat exposure [27]. Although microbial communities may be associated with decreased feed intake, but HS-induced changes in bacterial communities was independent of reduced feed intake because there was no difference in microbial communities in pair-feeding (when feed intake level in the thermoneutral condition was controlled to the intake level of HS group) and thermoneutral animals [25]. From the above discussion, it is clear that heat challenge usually changes overall microbial community composition independent A C C E T E D of feed intake, but impacts may differ in different gut segments depending upon duration of exposure.…”

Choline and Bile Acids Mixture Improved Growth Performance and Intestinal Immunity via Altering Gut Microbiota and Bacterial Metabolites in the Colon of Weaned Piglets.

“…The library was sequenced on an Illumina NovaSeq platform and 250 bp paired-end reads were generated. Bioinformatics analysis was conducted following a recent study [21].…”

Problems of animal husbandry intensification and ways to solve them

“…Под действием стресса происходит изменение состава микробиоты и проницаемости кишечника, что сказывается на доступности питательных веществ и энергетического обмена [9,12]. Использование пробиотических добавок оказывает положительное влияние при стрессовых нагрузках.…”