Effects of intermittent cold stimulation on antioxidant capacity and mRNA expression in broilers

Effects of Acute Cold Stress after Intermittent Cold Stimulation on Immune-Related Molecules, Intestinal Barrier Genes, and Heat Shock Proteins in Broiler Ileum

Cold stress will have a negative impact on animal welfare and health. In order to explore the effect of intermittent cold stimulation training on the cold resistance of broilers. Immune-related and intestinal barrier genes were detected before and after acute cold stress (ACS), aiming to find an optimal cold stimulation training method. A total of 240 1-day-old Ross broilers (Gallus) were divided into three groups (G1, G2, and G3), each with 5 replicates (16 chickens each replicate). The broilers of G1 were raised at normal temperature, while the broilers of G2 and G3 were treated with cold stimulation at 3 °C lower than the G1 for 3 h and 6 h from 15 to 35 d, respectively, at one-day intervals. At 50 d, the ambient temperature for all groups was reduced to 10 °C for six hours. The results demonstrated that before ACS, IL6, IL17, TLR21, and HSP40 mRNA levels in G3 were apparently down-regulated (p < 0.05), while IL8 and Claudin-1 mRNA levels were significantly up-regulated compared with G1 (p < 0.05). After ACS, IL2, IL6, and IL8 expression levels in G3 were lower than those in G2 (p < 0.05). Compared to G2, Claudin-1, HSP90 mRNA levels, HSP40, and HSP70 protein levels were increased in G3 (p < 0.05). The mRNA levels of TLR5, Mucin2, and Claudin-1 in G2 and IL6, IL8, and TLR4 in G3 were down-regulated after ACS, while IL2, IL6, and IL17 mRNA levels in G2 and HSP40 protein levels in G3 were up-regulated after ACS (p < 0.05). Comprehensive investigation shows that cold stimulation at 3 °C lower than the normal feeding temperature for six hours at one day intervals can enhanced immune function and maintain the stability of intestinal barrier function to lessen the adverse effects on ACS in broilers.

Effect of mild intermittent cold stimulation on thymus immune function in broilers

This study aims to assess the effect of intermittent and mild cold stimulation (IMCS) on thymus function and the ability of 1-day-old male Ross 308 broilers to withstand cold. Four hundred broilers were reared under normal and mild cold temperatures at 3°C below the normal feeding temperature and were subjected to acute cold stress (ACS) at 10°C on d 50 at 7 am for 6 h, 12 h, and 24 h. We determined the expression levels of toll-like receptors (TLRs), cytokines and avian β-defencins (AvBDs), encoding genes in thymus of broilers at 22, 36, 43, and 50 d of age, and the serum ACTH and cortisol (CORT) levels at 50 d of age. At D22 and D36, the mRNA expression levels of TLRs and AvBDs genes in CS groups were generally significantly decreased (P < 0.05). The lowest expression levels were found in birds submitted to intermittent and mild cold stimulation training for 5 h (CS5 group) on d 22 and 36 of development (P < 0.05). At D43 and D49 after IMCS, mRNA expression levels of most TLRs and AvBDs were significantly lower than those in CC group (P < 0.05), and that mRNA expression levels of all TLRs and most AvBDs in CS5 group had the same change trend with age as those in CC group (P > 0.05). At D22 and D36, mRNA expression levels of different cytokines in each CS groups were different (P < 0.05). mRNA expression levels of IL-2, IL-4, IL-6, IL-8, IL-17, and IFN-α all reached the highest values in the CS5 group at D36 (P < 0.05). The levels of ACTH and CORT in all IMCS-treated birds changed in varying degrees after ACS, but there was no significant change in CS5 group (P > 0.05). Collectively, different cold stimulation schemes could modulate thymus immune function of broilers by maintaining homeostasis and enhancing cold resistance. In particular, the optimal cold adaptation scheme was at 3°C below the conventional feeding temperature for 5 h.

Effects of polysaccharides from Yingshan Yunwu tea on free amino acids, flavor nucleotides and antioxidant abilities in chickens

Tea polysaccharides possess a variety of physiological activities including anti-oxidant, anti-cancer, anti-diabetic, immunomodulatory, hypolipidemic, and cation chelating ability, which have been proved a promising feed additive. Our study aimed to investigate the effects of polysaccharides from Yingshan Yunwu tea (GTPS) on free amino acids, flavor nucleotides and antioxidant ability in chickens. A total of 200 chickens were randomly divided into to 4 groups. Chickens were fed chicken basal diet with GTPS (200, 400 and 800 mg/kg). The results showed that GTPS increased body weight, average daily gain, and average daily feed intake in chickens. Moreover, GTPS increased the total amount of free amino acids of meat, and increased the content of histidine, leucine, serine, glutamic acid and alanine. GTPS also increased contents of inosine monophosphate and guanylic monophosphate, which improved the meat flavor of chickens. In addition, GTPS significantly increased (P < 0.05) contents of GSH-Px, SOD and T-AOC, and reduced content of MDA. It also increased Nrf2, NQO-1 and HO-1 mRNA expressions, and decreased Keap1expression. GTPS increased Nrf2 and HO-1 protein levels, and decreased Keap1 level. The above findings indicated that GTPS could be a promising natural feed additive in poultry industry.

Intermittent mild cold stimulation improves the immunity and cold resistance of spleens in broilers

In order to investigate the effect of intermittent mild cold stimulation (IMCS) on immune function of spleens and adaptability to cold stress in broilers, 400 healthy 1-day-old Ross-308 chickens were divided into 5 groups: CC (control) reared in normal thermal environment from 1 to 49 d; CS3, CS4, CS5, and CS6 (treatments) raised at 3°C below the temperature of CC for 3, 4, 5, or 6 h at 1-d intervals from 15 to 35 d, respectively. Subsequently, CS3-6 was raised at 20°C from 36 to 49 d. At 50 d, all groups were exposed to acute cold stress (ACS) for 12 h. The spleen immunity index at 22, 29, 36, 43, and 49 d, expression levels of toll-like receptors (TLRs), cytokines and immunoglobulins at 22, 43, and 49 d and heat shock proteins (HSPs) before and after ACS at 50 d were examined. The spleen index of broilers aged 22 to 49 d did not differ between CS and CC (P > 0.05), and the spleen index of CS5 was higher than that of CS3 at 49 d (P < 0.05). The mRNA levels of TLR5, TLR15, TLR21, and IL-2 in CS3, TLR3, TLR4, TLR15, TLR21, IL-2, IL-6, and IFN-ϒ in CS4, TLR1, TLR3, TLR4, TLR21, IL-2, IFN-a, IFN-ϒ, IgA, and IgG in CS6, but all TLRs, immunoglobulins and cytokines except IFN-ϒ in CS5 differential expressed stably compared with CC at 43 and 49 d (P < 0.05). Compared with Pre-ACS, the mRNA levels of HSP60, HSP70, and HSP90 were upregulated in CS after ACS (P < 0.05). Except for HSP90 mRNA and HSP70 protein in CS6, and HSP90 protein in CS3, the levels of HSPs after ACS in all treatment groups were higher than those in CC (P < 0.05), and the highest HSPs levels after ACS were found in CS5. We concluded that IMCS could enhance immunity of spleens and adaptability to ACS in broilers, besides CS5 was the optimal program.

Detrimental or beneficial? Untangling the literature on developmental stress studies in birds

Developing animals display a tremendous ability to change the course of their developmental path in response to the environment they experience, a concept referred to as developmental plasticity. This change in behavior, physiology or cellular processes is primarily thought to allow animals to better accommodate themselves to the surrounding environment. However, existing data on developmental stress and whether it brings about beneficial or detrimental outcomes show conflicting results. There are several well-referred hypotheses related to developmental stress in the current literature, such as the environmental matching, silver spoon and thrifty phenotype hypotheses. These hypotheses speculate that the early-life environment defines the capacity of the physiological functions and behavioral tendencies and that this change is permanent and impacts the fitness of the individual. These hypotheses also postulate there is a trade-off among organ systems and physiological functions when resources are insufficient. Published data on avian taxa show that some effects of developmental nutritional and thermal stressors are long lasting, such as the effects on body mass and birdsong. Although hypotheses on developmental stress are based on fitness components, data on reproduction and survival are scarce, making it difficult to determine which hypothesis these data support. Furthermore, most physiological and performance measures are collected only once; thus, the physiological mechanisms remain undertested. Here, we offer potential avenues of research to identify reasons behind the contrasting results in developmental stress research and possible ways to determine whether developmental programming due to stressors is beneficial or detrimental, including quantifying reproduction and survival in multiple environments, measuring temporal changes in physiological variables and testing for stress resistance later in life.

Effects of Cold Exposure on Performance and Skeletal Muscle Fiber in Weaned Piglets

Low-temperature is one of the most significant risks for the animal industry. In light of this, the present study aimed to explore the effects of low-temperature on growth performance, nutrient digestibility, myofiber types and mitochondrial function in weaned piglets. A total of sixteen 21-day-old male Duroc × Landrace × Yorkshire (DLY) piglets were randomly divided into a control group (CON, 26 ± 1 °C) and a low-temperature group (LT, 15 ± 1 °C), with eight duplicate piglets in each group. The trial period lasted for 21 days. We showed that LT not only increased the ADFI (p < 0.05), as well as increasing the diarrhea incidence and diarrhea index of weaned piglets in the early stage of the experiment (p < 0.01), but it also decreased the apparent digestibility of crude protein (CP), organic matter (OM) and dry matter (DM) (p < 0.05). Meanwhile, in the LT group, the mRNA expression of MyHC IIa (p < 0.05) in longissimus dorsi muscle (LM) and MyHC I (p < 0.01) in psoas muscle (PM) were increased, while the mRNA expression of MyHC IIx in PM was decreased (p < 0.05). In addition, LT increased the mRNA expression of mitochondrial function-related genes citrate synthase (CS) and succinate dehydrogenase-b (SDHB) in LM, as well as increased the mRNA expression of CS (p < 0.05) and carnitine palmitoyl transferase-1b (CPT-1b) (p < 0.01) in PM. Furthermore, LT increased the T-AOC activity in serum and LM (p < 0.01), as well as increased the T-SOD activity in PM (p < 0.05). Taken together, these findings showed that low-temperature could negatively affect the growth performance and nutrient digestibility, but resulted in a shift toward oxidative muscle fibers, which may occur through mitochondrial function regulation.

Changes in Rumen Microbiota Affect Metabolites, Immune Responses and Antioxidant Enzyme Activities of Sheep under Cold Stimulation

Simple Summary

Under a cold environment, the animal’s weight is reduced and even health is affected. As we all know, microbiota is beneficial to animal health. It can produce metabolites to improve animal immunity and avoid damage. Therefore, we aimed to understand the self-protection mechanisms of sheep under cold stress. To investigate this mechanism, we designed two experiments to explore the effects of low temperature and wind speed on sheep phenotypes, rumen microbes, immune cytokines and oxidative stress. Our results identified that the sheep remained healthy in a cold environment. This may be due to the enrichment of Lachnospiraceae in the rumen. A large amount of propionate may enter into the gluconeogenesis reaction, resulting in a decrease in the content of propionate in the rumen, thereby reducing animal’s immunity. In summary, the increase of Lachnospiraceae and propionate in the rumen may help sheep live in a cold environment. Our experiments provide some direction for the healthy feeding of animals in cold environments.

Abstract

Low-temperature environments can strongly affect the normal growth and health of livestock. In winter, cold weather can be accompanied by strong winds that aggravate the effects of cold on livestock. In this study, two experiments were conducted to investigate the effect of low temperature and/or wind speed on physiological indices, rumen microbiota, immune responses and oxidative stress in sheep. When sheep were exposed to cold temperature and/or stronger wind speeds, the average daily gain (ADG) decreased (p < 0.05), and the abundance of Lachnospiraceae was significantly higher (p < 0.05). The acetate and propionate contents and the proportion of propionate in the rumen also significantly reduced (p < 0.05). The immunoglobulin G (IgG) and TH1-related cytokines in the blood were significantly lower (p < 0.05). However, antioxidant enzyme contents were significantly increased and the concentration of malondialdehyde (MDA) was reduced (p < 0.05). In a cold environment, the abundance of Lachnospiraceae in the rumen of sheep was highly enriched, and the decreasing of propionate might be one of the factors affecting the immunity of the animals, the sheep did not suffer from oxidative damage during the experiment.

Effect of Intermittent and Mild Cold Stimulation on the Immune Function of Bursa in Broilers

Cold stress causes growth performance to decrease and increases production costs. Cold adaptation can enhance immune function and alleviate the negative impact caused by the stress condition. The study investigated the effect of intermittent and mild cold stimulation on the immune function of the bursa of Fabricius in broilers. A total of 400 healthy one-day-old broilers were divided into the control group (CC) and cold stimulation (CS) groups. The CC group was raised at a conventional raising temperature of broilers, while the CS groups were raised at 3°C below the temperature of the CC for three-, four-, five-, or six-hour periods at one-day intervals from 15 to 35 days of age (D35), denoted CS3, CS4, CS5, and CS6, respectively. Subsequently, they were raised at 20°C from 36 to 49 days of age (D49). The expression levels of TLRs, cytokines, and AvBDs were determined to access the immune function of bursa in broilers. After 21-day IMCS (at D36), the expression levels of TLR1, TLR15 and TLR21, interleukin (IL)-8, and interferon (IFN)-γ, as well as AvBD8 in CS groups, were lower than those in CC (p < 0.05). The expression levels of TLR3, TLR4 and TLR7, were decreased in the CS3, CS5, and CS6 groups (p < 0.05), but there were no significant differences in both the CC and CS4 groups (p > 0.05). When the IMCS ended for 14 days (at D49), the expression levels of TLR2, TLR3, TLR5, TLR7, TLR15, and TLR21, and IL-8, as well as AvBD2, AvBD4 and AvBD7 in CS groups, were lower than those in CC (p < 0.05). In addition to CS4, the expression levels of TLR1, IFN-γ, and AvBD8 in CS3, CS5, and CS6 were still lower than those in CC (p < 0.05). We concluded that the intermittent and mild cold stimulation could regulate immunoreaction by modulating the production of TLRs, cytokines, and AvBDs in the bursa, which could help broilers adapt to low ambient temperature and maintain homeostasis.

Proper cold stimulation starting at an earlier age can enhance immunity and improve adaptability to cold stress in broilers

The effects of long-term cold stimulation on the immune function of ileum and adaptability to cold stress in broilers were examined. A total of 360 Arbor Acres broilers was divided into 3 groups and four replicates per group. C (control) was reared in normal thermal environment. C-3 and C-12 (treatments) were kept in cold condition of 3 or 12°C lower than the temperature of C from days 8 to 42. At day 42, all the groups were exposed to an acute cold stress challenge, designated as S, S-3, and S-12. The mRNA levels of immune molecules and heat shock proteins as well as oxidative stress-related indicators in ileum tissues, and immunoglobulins contents in serum were examined at 14, 42, and 43 d of age. The C-3 regimen had no adverse effect on production performance, whereas the C-12 regimen reduced the production performance relative to C (P < 0.05). At day 42, C-3 had higher levels of immune indexes (P < 0.05), whereas C-12 had lower levels than C (P < 0.05). No differences in levels of oxidative stress-related indicators were found between C and C-3 at day 42 (P > 0.05). S-3 had higher levels of immune indexes and lower levels of oxidative stress-related indicators (P < 0.05), as compared to S and S-12. The results suggest that 34 d of cold stimulation at 3°C lower than the normal temperature had no adverse impacts on production performance but enhanced the immunity of ileum and adaptability to acute cold challenge in broilers.

Chemical Composition and Antioxidant Activities of Polysaccharides from Yingshan Cloud Mist Tea

The study was designed to investigate the chemical composition and antioxidant activities of polysaccharides from Yingshan Cloud Mist Tea. The chemical composition of green tea polysaccharides (GTPS) was analyzed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), thermogravimetric (TGA), gas chromatograph (GC), and high-performance gel-permeation chromatography (HPGPC). Then, the antioxidant activities in vitro of GTPS, effects of GTPS on body weight, and the antioxidant activities in chickens were studied. The results showed that GTPS were composed of rhamnose (Rha), arabinose (Ara), xylose (Xyl), mannose (Man), glucose (Glu), and galactose (Gal) in a molar ratio of 11.4 : 26.1 : 1.9 : 3.0 : 30.7 : 26.8 and the average molecular weight was 9.69×104 Da. Furthermore, GTPS exhibited obvious capacity of scavenging DPPH radical, hydroxyl radical, and superoxide radical and enhanced the ferric-reducing power in vitro. Last, GTPS significantly increased the body weight of chickens, enhanced the T-AOC, SOD, and GSH-Px level, and decreased the content of MDA in chickens. The results indicated that GTPS might be a kind of natural antioxidant, which had the potential application in feed industry.

Chemical Composition and Antioxidant Activities of Polysaccharides from Yingshan Cloud Mist Tea

The study was designed to investigate the chemical composition and antioxidant activities of polysaccharides from Yingshan Cloud Mist Tea. The chemical composition of green tea polysaccharides (GTPS) was analyzed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), thermogravimetric (TGA), gas chromatograph (GC), and high-performance gel-permeation chromatography (HPGPC). Then, the antioxidant activities in vitro of GTPS, effects of GTPS on body weight, and the antioxidant activities in chickens were studied. The results showed that GTPS were composed of rhamnose (Rha), arabinose (Ara), xylose (Xyl), mannose (Man), glucose (Glu), and galactose (Gal) in a molar ratio of 11.4 : 26.1 : 1.9 : 3.0 : 30.7 : 26.8 and the average molecular weight was 9.69×104 Da. Furthermore, GTPS exhibited obvious capacity of scavenging DPPH radical, hydroxyl radical, and superoxide radical and enhanced the ferric-reducing power in vitro. Last, GTPS significantly increased the body weight of chickens, enhanced the T-AOC, SOD, and GSH-Px level, and decreased the content of MDA in chickens. The results indicated that GTPS might be a kind of natural antioxidant, which had the potential application in feed industry.

Chemical Composition and Antioxidant Activities of Polysaccharides from Yingshan Cloud Mist Tea

The study was designed to investigate the chemical composition and antioxidant activities of polysaccharides from Yingshan Cloud Mist Tea. The chemical composition of green tea polysaccharides (GTPS) was analyzed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), thermogravimetric (TGA), gas chromatograph (GC), and high-performance gel-permeation chromatography (HPGPC). Then, the antioxidant activities in vitro of GTPS, effects of GTPS on body weight, and the antioxidant activities in chickens were studied. The results showed that GTPS were composed of rhamnose (Rha), arabinose (Ara), xylose (Xyl), mannose (Man), glucose (Glu), and galactose (Gal) in a molar ratio of 11.4 : 26.1 : 1.9 : 3.0 : 30.7 : 26.8 and the average molecular weight was 9.69 × 10⁴ Da. Furthermore, GTPS exhibited obvious capacity of scavenging DPPH radical, hydroxyl radical, and superoxide radical and enhanced the ferric-reducing power in vitro. Last, GTPS significantly increased the body weight of chickens, enhanced the T-AOC, SOD, and GSH-Px level, and decreased the content of MDA in chickens. The results indicated that GTPS might be a kind of natural antioxidant, which had the potential application in feed industry.

Effects of Acute Cold Stress After Long-Term Cold Stimulation on Antioxidant Status, Heat Shock Proteins, Inflammation and Immune Cytokines in Broiler Heart

To investigate the effects of acute cold stress (ACS) on chicken heart after cold stimulation, female broilers were raised in either normal (C) or gradually decreasing temperatures (CS I and CS II) for 34 days followed by a 24 h ACS at 7°C. Cardiac tissues were collected from the pre-ACS and ACS time points to analyze the histopathological changes, antioxidant status and the expression of heat shock proteins, inflammatory factors and immune-related cytokines. The CS II heart tissues showed shrunken cell membranes and nuclei, disordered or ruptured myocardial fibers, higher MDA content and upregulation in HSP27, HSP40, HSP70, NF-κB, COX-2, PTGEs, iNOS, TNF-α and IL-4 mRNAs, and in protein levels of HSP40, NF-κB and iNOS and reduction in CAT, GSH-px and SOD activity, as well as HSP90 and IFN-γ levels compared to the control tissues before ACS. In contrast, the HSPs were significantly increased, and the inflammatory and immune related factors were unaltered prior to the ACS in the CS I compared to the C group. Following ACS, MDA content was significantly increased and antioxidant activity was significantly decreased in the CS I and CS II groups compared to the C group. The levels of HSP27, HSP70, HSP90, inflammatory factors and IL-4 were significantly reduced and that of IFN-γ was significantly increased in CS I broiler hearts; the reverse trends were seen in CS II relative to CS I. Compared to the pre-ACS levels, that of HSP27, HSP40, HSP60, inflammatory factors and IL-4 were increased and IFN-γ was decreased in the C and CS II groups after ACS. Therefore, cold stimulation at drastically lower temperatures induced cardiac damage, which was further aggravated by ACS. In contrast, cold stimulation at only 3°C lower than normal temperature improved the adaptability of the broilers to ACS.