Effects of Herbal Adaptogen Feed-Additive on Growth Performance, Carcass Parameters, and Muscle Amino Acid Profile in Heat-Stressed Modern Broilers

Effects of an herbal adaptogen feed-additive on feeding-related hypothalamic neuropeptides in chronic cyclic heat-stressed chickens

Heat stress (HS) is a global serious issue in the poultry industry with numerous adverse effects, including increased stress, depressed feed intake (FI), poor growth performance and higher mortality. Herbal adaptogens, plant extracts considered as stress response modifiers, are metabolic regulators that improve an organism's ability to adapt to and minimize damage from environmental stresses. Previously, we showed that herbal adaptogen supplementation increased FI and body weight (BW) of broiler (meat-type) chickens reared under HS conditions. Therefore, we hypothesized that these effects may be mediated through modulation of hypothalamic feeding-related neuropeptides. Male Cobb 500 chicks were reared in 12 environmental chambers with three diets: a corn-soybean-based diet (C) and two herbal adaptogen-supplemented diets at 500 g/1000 kg (NR-PHY-500) and 1 kg/1000 kg (NR-PHY-1000). Broilers in 9 chambers were exposed to chronic cyclic HS (35 °C for 8 h/day) from d29 to d42, while 3 chambers were maintained at 24 °C (thermoneutral, TN) for all 42 days. Hypothalamic samples were collected on d42 from each group, both before the onset of HS (Pre-HS) that day and after 3 h of HS (post-HS). Hypothalamic expressions of neuropeptide Y (NPY) receptors Y4 and Y7, Corticotropin-releasing hormone (CRH), orexin receptor 1 (ORXR1), melanocortin receptors (MC1R, MC4R, and MC5R), visfatin and neurosecretory protein GL (NPGL) genes were significantly upregulated by adaptogen supplementation. The hypothalamic expression of MC2R was affect by period, with a significant upregulation during post-HS phase. There was a significant period by treatment interaction for hypothalamic orexin and adiponectin expression. The hypothalamic expression of NPY, Y1, Y2, Y5, Y6, proopiomelanocortin (POMC), cocaine and amphetamine regulated transcript (CART), agouti-related peptide (AgRP), ORXR2, AdipR1/2, MC3R, and ghrelin was not affected by diet supplementation nor by HS exposure. In conclusion, these findings suggest that in-feed supplementation of adaptogen might improve FI and growth via modulation of hypothalamic feeding-related neuropeptides in heat-stressed broilers.

Effect of heat stress on the hypothalamic expression profile of water homeostasis-associated genes in low- and high-water efficient chicken lines

With climate change, selection for water efficiency and heat resilience are vitally important. We undertook this study to determine the effect of chronic cyclic heat stress (HS) on the hypothalamic expression profile of water homeostasis-associated markers in high (HWE)- and low (LWE)-water efficient chicken lines. HS significantly elevated core body temperatures of both lines. However, the amplitude was higher by 0.5-1°C in HWE compared to their LWE counterparts. HWE line drank significantly less water than LWE during both thermoneutral (TN) and HS conditions, and HS increased water intake in both lines with pronounced magnitude in LWE birds. HWE had better feed conversion ratio (FCR), water conversion ratio (WCR), and water to feed intake ratio. At the molecular level, the overall hypothalamic expression of aquaporins (AQP8 and AQP12), arginine vasopressin (AVP) and its related receptor AVP2R, angiotensinogen (AGT), angiotensin II receptor type 1 (AT1), and calbindin 2 (CALB2) were significantly lower; however, CALB1 mRNA and AQP2 protein levels were higher in HWE compared to LWE line. Compared to TN conditions, HS exposure significantly increased mRNA abundances of AQPs (8, 12), AVPR1a, natriuretic peptide A (NPPA), angiotensin I-converting enzyme (ACE), CALB1 and 2, and transient receptor potential cation channel subfamily V member 1 and 4 (TRPV1 and TRPV4) as well as the protein levels of AQP2, however it decreased that of AQP4 gene expression. A significant line by environment interaction was observed in several hypothalamic genes. Heat stress significantly upregulated AQP2 and SCT at mRNA levels and AQP1 and AQP3 at both mRNA and protein levels, but it downregulated that of AQP4 protein only in LWE birds. In HWE broilers, however, HS upregulated the hypothalamic expression of renin (REN) and AVPR1b genes and AQP5 proteins, but it downregulated that of AQP3 protein. The hypothalamic expression of AQP (5, 7, 10, and 11) genes was increased by HS in both chicken lines. In summary, this is the first report showing improvement of growth performances in HWE birds. The hypothalamic expression of several genes was affected in a line- and/or environment-dependent manner, revealing potential molecular signatures for water efficiency and/or heat tolerance in chickens.

Growth performance, blood biochemistry, and mRNA expression of hepatic heat shock proteins of heat-stressed broilers in response to rosemary and oregano extracts

The growing interest in countering the adverse effects of heat stress in poultry using phytogenic feed additives has garnered considerable attention in recent times, this research sought to examine the impact of rosemary leaves extract (RLE) and oregano leaves extract (OLE) on the growth performance, physiological responses, and hepatic mRNA expression of heat shock proteins in broiler chickens exposed to heat stress. A total of 150 male Indian River chicks, aged one day, were randomly allocated into five equally sized groups, each consisting of six replicates. The initial group was designated as the control and was provided with the basal diet. The second and third groups (R1 and R2) were administered the basal diet enriched with 50 and 100 mg/kg of rosemary leaves extract (RLE), respectively. The fourth and fifth groups (O1 and O2) were fed the basal diet supplemented with 50 and 100 mg/kg of oregano leaves extract (OLE), respectively. These chicks were reared in a controlled environmental chamber maintained at a temperature of 32±2 °C and relative humidity of 50 ± 5 %. Ferruginol was the leading component in RLE, whereas thymol was the prevalent constituent in OLE. RLE and OLE both have high DPPH• and ABTS•+ antioxidant potential. Among the experimental groups, the fourth group (O1) showed the heaviest live body weight and the lowest feed conversion ratio, indicating improved growth performance. There was a significant reduction in plasma total lipids and LDL-cholesterol levels within the R2 and O2 groups, respectively. Enhanced total antioxidant capacity and an improvement in the T3 hormone were observed in the R1 and R2 groups. In the second and fourth groups, the mRNA expression of hsp70 and 90A were both found to be significantly downregulated, respectively. In conclusion, the addition of 50 mg/kg of oregano leaves extract (OLE) to the diets of heat-stressed broilers resulted in improved hepatic heat shock proteins, along with certain physiological responses, ultimately contributing to enhanced growth performance.

Impact of buffered sodium butyrate as a partial or total dietary alternative to lincomycin on performance, IGF-1 and TLR4 genes expression, serum indices, intestinal histomorphometry, Clostridia, and litter hygiene of broiler chickens

BACKGROUND

Sodium butyrate (SB) is a short-chain fatty acid and a safe antibiotic alternative. During 35 days, this study compared the impact of coated SB (Butirex C4) and lincomycin (Lincomix) on broiler growth, gut health, and litter hygiene in 1200 one-day-old Ross-308 broiler chicks that were randomly assigned into 5-dietary groups with 5-replications each. Groups divided as follows: T1: Basal diet (control), T2: Basal diet with buffered SB (1 kg/ton starter feed, 0.5 kg/ton grower-finisher feeds), T3: Basal diet with 100 g/ton lincomycin, T4: Basal diet with buffered SB (0.5 kg/ton starter feed, 0.25 kg/ton grower-finisher feeds) + 50 g/ton lincomycin, and T5: Basal diet with buffered SB (1 kg/ton starter feed, 0.5 kg/ton grower-finisher feeds) + 50 g/ton lincomycin. Birds were housed in a semi-closed deep litter house, where feed and water were available ad libitum. Results were statistically analyzed using ANOVA and Tukey's post hoc tests.

RESULTS

Combined dietary supplementation with SB and lincomycin (T4 and T5) significantly enhanced body weights, weight gains, feed conversion ratio, and profitability index. Also, carcasses in T4 and T5 exhibited the highest dressing, breast, thigh, and liver yields. T5 revealed the best blood biochemical indices, while T3 showed significantly elevated liver and kidney function indices. T4 and T5 exhibited the highest expression levels of IGF-1 and TLR4 genes, the greatest villi length of the intestinal mucosa, and the lowest levels of litter moisture and nitrogen. Clostridia perfringens type A alpha-toxin gene was confirmed in birds' caeca, with the lowest clostridial counts defined in T4.

CONCLUSIONS

Replacing half the dose of lincomycin (50 g/ton) with 0.5 or 1 kg/ton coated SB as a dietary supplement mixture showed the most efficient privileges concerning birds' performance and health.

The effects of essential oil from Lippia origanoides and herbal betaine on performance, intestinal integrity, bone mineralization and meat quality in broiler chickens subjected to cyclic heat stress

Essential oils (EO) affect performance, intestinal integrity, bone mineralization, and meat quality in broiler chickens subjected to cyclic heat stress (HS). Day-of-hatch Cobb 500 male broiler chicks (n = 475) were randomly divided into four groups. Group 1: No heat stress (Thermoneutral) + control diets with no antibiotics; Group 2: heat stress control + control diets; Group 3: heat stress + control diets supplemented with thymol chemotype (45 ppm) and herbal betaine (150 ppm) formulation EO1; Group 4: heat stress + control diets supplemented with phellandrene (45 ppm) and herbal betaine (150 ppm) formulation EO2. From day 10-42, the heat stress groups were exposed to cyclic HS at 35°C for 12 h (8:00-20:00). BW, BWG, FI, and FCRc were measured at d 0, 10, 28, and 42. Chickens were orally gavaged with FITC-d on days 10 (before heat stress) and 42. Morphometric analysis of duodenum and ileum samples and bone mineralization of tibias were done. Meat quality was assessed on day 43 with ten chickens per pen per treatment. Heat stress reduced BW by day 28 (p < 0.05) compared to thermoneutral chickens. At the end of the trial, chickens that received both formulations of EO1 and EO2 had significantly higher BW than HS control chickens. A similar trend was observed for BWG. FCRc was impaired by EO2 supplementation. There was a significant increase in total mortality in EO2 compared with EO1 EO1 chickens had lower FITC-d concentrations at day 42 than the HS control. In addition, EO1 treatment is not statistically different if compared to EO2 and thermoneutral. Control HS broilers had significantly lower tibia breaking strength and total ash at day 42 than heat-stressed chickens supplemented with EO1 and EO2. Heat stress affected intestinal morphology more than thermoneutral chickens. EO1 and EO2 improved intestinal morphology in heat-stressed chickens. Woody breast and white striping were more common in thermoneutral chickens than heat stress chickens. In conclusion, the EO-containing diet could improve broiler chicken growth during cyclic heat stress, becoming increasingly relevant in antibiotic-free production in harsh climates.

The study of the effect of drinks based on extracts of herbal adaptogens on the functional status of athletes during physical activity

Adverse environmental factors, stress, lack of sleep and rest, and heavy physical exertion, deplete the human body. In particular, the reserves of the main metabolites, water, and oxygen, are very limited. People, especially athletes, need to take special dietary supplements with adaptogenic properties to adapt to stressful extreme loads. In this study, the influence of using extracts of leuzea, ginseng, and Eleutherococcus on athletes' performance, endurance, strength, and emotional state is carried out. The studies were conducted on four groups of male athletes aged from 19 to 25 years. For three weeks, diagnostics of vital lung capacity, Stange, and Genchi tests are carried out, and data on the general impressions of athletes are collected. According to the research results, the use of adaptogens leads to an increase in physical performance. After the first week of the study, a positive effect on the human body are noticed: improve well-being and increased athletic performance. When using Eleutherococcus, there was a change in the work of the central nervous system (motor functions): tasks begin to be performed in an organized and accelerated manner without deterioration of well-being, but the volume of strength exercises remained the same. When using the drug leuzea, muscle strength was noted, which allowed to increase the load. There is a positive effect of phytopreparations on the body, namely on the functions of the cardiovascular, central nervous and endocrine systems. In 4 participants who took leuzea, the performance in power competitions improved by 18.5% compared to the control group. The intake of Eleutherococcus and ginseng is accompanied by an increase in the activity of neurotransmitter cells, i.e., the effect on the mesolimbic system.  In addition, a study of hematological blood parameters and hormonal statuses at the beginning and end of the study was conducted with the subjects who took leuzea extract. So, the use of the drug leuzea leads to the following positive changes: a more significant increase in ESR, a more significant increase in hemoglobin, compared with the control group. The conclusion is made about the practicality of taking biologically active additives based on some plant adaptogens.

Effect of Cyclic Heat Stress on Hypothalamic Oxygen Homeostasis and Inflammatory State in the Jungle Fowl and Three Broiler-Based Research Lines

Heat stress (HS) is devastating to poultry production sustainability due its detrimental effects on performance, welfare, meat quality, and profitability. One of the most known negative effects of HS is feed intake depression, which is more pronounced in modern high-performing broilers compared to their ancestor unselected birds, yet the underlying molecular mechanisms are not fully defined. The present study aimed, therefore, to determine the hypothalamic expression of a newly involved pathway, hypoxia/oxygen homeostasis, in heat-stressed broiler-based research lines and jungle fowl. Three populations of broilers (slow growing ACRB developed in 1956, moderate growing 95RB from broilers available in 1995, and modern fast growing MRB from 2015) and unselected Jungle fowl birds were exposed to cyclic heat stress (36°C, 9 h/day for 4 weeks) in a 2 × 4 factorial experimental design. Total RNAs and proteins were extracted from the hypothalamic tissues and the expression of target genes and proteins was determined by real-time quantitative PCR and Western blot, respectively. It has been previously shown that HS increased core body temperature and decreased feed intake in 95RB and MRB, but not in ACRB or JF. HS exposure did not affect the hypothalamic expression of HIF complex, however there was a line effect for HIF-1α (P = 0.02) with higher expression in JF under heat stress. HS significantly up regulated the hypothalamic expression of hemoglobin subunits (HBA1, HBBR, HBE, HBZ), and HJV in ACRB, HBA1 and HJV in 95RB and MRB, and HJV in JF, but it down regulated FPN1 in JF. Additionally, HS altered the hypothalamic expression of oxygen homeostasis- up and down-stream signaling cascades. Phospho-AMPK^Thr172 was activated by HS in JF hypothalamus, but it decreased in that of the broiler-based research lines. Under thermoneutral conditions, p-AMPK^Thr172 was higher in broiler-based research lines compared to JF. Ribosomal protein S6K1, however, was significantly upregulated in 95RB and MRB under both environmental conditions. HS significantly upregulated the hypothalamic expression of NF-κB2 in MRB, RelB, and TNFα in ACRB, abut it down regulated RelA in 95RB. The regulation of HSPs by HS seems to be family- and line-dependent. HS upregulated the hypothalamic expression of HSP60 in ACRB and 95RB, down regulated HSP90 in JF only, and decreased HSP70 in all studied lines. Taken together, this is the first report showing that HS modulated the hypothalamic expression of hypoxia- and oxygen homeostasis-associated genes as well as their up- and down-stream mediators in chickens, and suggests that hypoxia, thermotolerance, and feed intake are interconnected, which merit further in-depth investigations.

Heat Stress Affects Jejunal Immunity of Yellow-Feathered Broilers and Is Potentially Mediated by the Microbiome

In the perspective of the global climate change leading to increasing temperature, heat stress (HS) has become a severe issue in broiler production, including the indigenous yellow-feathered broilers. The present study aimed to investigate the effects of HS on jejunal immune response, microbiota structure and their correlation in yellow-feathered broilers. A total of forty female broilers (56-days-old) were randomly and equally divided into normal treatment group (NT group, 21.3 ± 1.2°C, 24 h/day) and HS group (32.5 ± 1.4°C, 8 h/day) with five replicates of each for 4 weeks feeding trial. The results showed that HS exposure increased the contents of TNF-α, IL-1β, and IL-6 in jejunal mucosa (p < 0.05). The HS exposure up-regulated the relative fold changes of NF-κB, TNF-α, IL-1β, and IL-6 (p < 0.01) while down-regulated the relative fold change of IFN-γ in jejunal mucosa (p < 0.05). Meanwhile, HS had no significant impacts on alpha diversity of jejunal microbiota such as Simpson, Chao1 richness estimator (Chao 1), abundance-based coverage estimators (ACE), and Shannon index (p > 0.10). Broilers exposed to HS reduced the jejunal microbial species number at the class and order level (p < 0.05). Moreover, HS decreased the relative abundance of Ruminococcus, Bdellovibrio, and Serratia at the genus level in jejunum (p < 0.05). At the phylum level, four species of bacteria (Bacteroidetes, Cyanobacteria, Thermi, and TM7) were significantly associated with immune-related genes expression (p < 0.05). At the genus level, ten species of bacteria were significantly correlated with the expression of immune-related genes (p < 0.05), including Caulobacteraceae, Actinomyces, Ruminococcaceae, Thermus, Bdellovibrio, Clostridiales, Sediminibacterium, Bacteroides, Sphingomonadales and Ruminococcus. In particular, the microbial with significantly different abundances, Ruminococcus and Bdellovibrio, were negatively associated with pro-inflammatory cytokines expression (p < 0.05). These findings demonstrated that HS exposure promoted the production of pro-inflammatory cytokines in yellow-feathered broilers’ jejunum. The detrimental effects of HS on jejunal immune response might be related to dysbiosis, especially the reduced levels of Ruminococcus and Bdellovibrio.