Search Results (59)

Background: Phytogenic feed additives may provide sustainable alternatives for improving poultry productivity and health. This study evaluated the chemical composition, antioxidant activity, and in vivo effects of a 1:1 Eucommia ulmoides leaf–Astragalus membranaceus complex (EG) in yellow-feathered broilers. Methods: The nutritional composition, bioactive compounds, and antioxidant activity of EG were characterized. A total of 200 one-day-old yellow-feathered broilers were randomly allocated into four dietary treatments with five replicates per group and 10 birds per replicate: the control group (CG) receiving a basal diet and three EG supplementation groups receiving diets supplemented with 0.5% (EG (0.5%)), 1.0% (EG (1.0%)), 2.0% (EG (2.0%)) Eucommia ulmoides leaf-Astragalus membranaceus complex for 42 days. Growth performance, serum antioxidant and immune indicators, intestinal microbiota composition, and serum metabolomic profiles were analyzed. Results: EG contained 46.53% polysaccharides and exhibited concentration-dependent radical-scavenging activity. Supplementation with EG (0.5%) consistently increased body weight and average daily gain and reduced the feed conversion ratio without affecting feed intake. EG increased serum antioxidant enzyme activities and immunoglobulin concentrations but did not affect routine biochemical parameters. The EG (0.5%) group was therefore selected for microbiome and metabolome analyses. EG altered jejunal and cecal microbial composition without significantly affecting α-diversity and increased cecal Faecalibacterium and Blautia at day 21 and Faecalibacterium and Parabacteroides at day 42. Metabolomics identified 103 differential metabolites associated mainly with amino acid, glycerophospholipid, and energy metabolism. Spearman’s analysis further associated Bacteroidota, Bacillota, Enterococcus, and Blautia with amino acid, carbohydrate, and lipid-related metabolites. Conclusions: These findings indicate that EG (0.5%) may improve growth and feed efficiency while modulating antioxidant status, humoral immune indices, intestinal microbial composition, and systemic metabolism in yellow-feathered broilers. Full article

The aim of the study was to evaluate the relationship between horses’ behaviour during olfactory exploration and following consumption of the same food containing herbs, either previously exposed to the herb odour or not. Twenty horses’ responses to 14 herbs were compared in a smelling test, when the horses sniffed a herb, and after 20 min a consumption test, when they consumed oats mixed with the same herb. Before the tests, the horses were exposed to the scent of seven herbs, whereas the remaining seven herbs were non-pre-exposed. The results show that horses consumed oats with herbal additives, regardless of whether pre-exposed, significantly longer than oats alone. The possibility of changes in feeding behaviour should be taken into account in horse feeding management when introducing new feeds or herbal supplements. Times of sniffing and consuming a herb were not correlated, whereas significant correlations in specific behaviours between the smelling and consumption tests were few and weak (from −0.162 to +0.146). It may be suggested that horses’ olfactory exploration of a feed has limited predictive value in relation to their subsequent consumption of it. The results should be treated as preliminary and considered a starting point for further research. Full article

The protective effects of herbal feed additives Withania somnifera, Silybum marianum, Centella asiatica, and silymarin (administered at feed levels of 4000 ppm, 5000 ppm, 4600 ppm, and 25,000 ppm, respectively) against the toxic effects of ochratoxin A (OTA) (administered at 2 ppm) were investigated in 48 New Zealand White rabbits (37 days old) over an 80-day experimental period. A decrease in body weight was seen in rabbits exposed to OTA alone, but that decrease was less pronounced in rabbits receiving herbal supplements. The most severe lesions in OTA-treated rabbits were found in the liver, kidneys and spleen, while milder lesions were seen in the heart, intestine and lungs. The intensity of macroscopic, histopathological and biochemical changes was highest in rabbits exposed to OTA alone, followed by rabbits additionally supplemented with herbal additives, as evidenced by histopathological findings and serum levels of blood urea nitrogen (BUN), creatinine, aspartate aminotransferase (AST), and alanine aminotransferase (ALT). The most pronounced protective effects of the herbal additives were observed in the kidneys and liver. Oxidative stress was significantly increased in rabbits exposed to OTA alone, as evidenced by elevated reactive oxygen species (ROS), nitric oxide (●NO), ascorbyl radicals (●Asc), protein oxidation (PO), procollagen type I alpha 1 (COL1A1), malondialdehyde (MDA), kidney injury molecule-1 (KIM-1), hydroxyproline (Hyp), advanced glycation end products (AEGs), heme oxygenase-1 (HO-1), catalase (CAT), and 8-hydroxy-2′-deoxyguanosine (8-OHdG), as well decreased superoxide dismutase (SOD) and glutathione peroxidase-1 (GPx-1) activities, while protective effects were seen for all herbal additives, and better expressed for Centella asiatica and Silybum marianum. Full article

This study aims to evaluate the effects of two phytobiotic mixtures on performance, nutrient digestibility, histomorphology, microbiota, and antioxidant status in fattening ducks. A total of 180 day-old male mixed-type ducks were randomly assigned to three dietary groups: a control group receiving a basal diet, and two treatment groups (PM1: commercial phytobiotic formulation containing menthol, eucalyptus oil and turmeric leaf oil as key ingredients and PM2: commercial phytobiotic formulation containing garlic oil as a key ingredient) supplemented at 250 g/ton of feed. Ducks were reared for 49 days with six replicates of ten ducks. Performance parameters, including body weight (BW), body weight gain (BWG), and average feed intake (AFI), were significantly improved in phytobiotic groups (p ≤ 0.05). Apparent digestibility of dry matter, crude protein, ether extract, and starch remained unaffected (p > 0.05). Histological analysis showed no significant differences in villus height (VH) or crypt depth (CD). However, cecal microbiota culture-based analysis revealed increased total anerobic bacteria and Lactobacillus counts in PM1 and PM2 (p ≤ 0.05). Antioxidant status demonstrated reduced MDA levels and elevated total phenolic content (TPC) and total antioxidant capacity (TAC) in breast and thigh tissues of treated ducks. Overall, phytobiotic supplementation improved performance and microbiota balance, supporting the potential application of these phytobiotic formulations at the inclusion level of 250 g/ton in fattening ducks’ nutrition. Full article

To investigate the effects of Wuwei Jianpi San (WJPS), a Chinese herbal compound feed additive, on rumen microecology, host metabolism, and immune function in healthy yaks (Bos grunniens), and to determine the optimal supplementation level, 32 yaks with similar initial body weight were randomly assigned to four groups: a control group and three groups receiving 0.5%, 1.0%, or 2.0% WJPS for 90 days. Growth performance, hematological indices, serum antioxidant and immune parameters, tryptophan metabolites, ruminal short-chain fatty acids (SCFAs), and rumen microbiota were analyzed. WJPS supplementation improved growth performance, as shown by a reduced feed-to-gain ratio in all treated groups and tended to increase average daily gain in the 2.0% group. It also enhanced hematological, antioxidant, and immune status, evidenced by increased white blood cell (WBC) and lymphocyte (Lym) counts and elevated interleukin-2 (IL-2), immunoglobulin G (IgG), and superoxide dismutase (SOD) levels. Moreover, 2.0% WJPS increased total SCFAs, acetate, and n-butyrate, while WJPS reduced kynurenine pathway metabolites, including kynurenine, 3-hydroxykynurenine, and quinolinic acid. Metagenomic analysis showed that WJPS tended to shape rumen microbial composition by increasing Bacillota and decreasing Bacteroidota, and these microbial changes were associated with host immune indices and tryptophan metabolism. Overall, 2.0% WJPS showed the best comprehensive effect. Full article

Abundant non-medicinal byproducts of Polygonatum sibiricum and Gentiana scabra are severely underutilized, resulting in resource waste and environmental burden. A previous study confirmed that triple-microbial co-fermentation enhances their antibacterial activity, yet the temporal metabolic mechanism and optimal process parameters remain unclear due to endpoint-only metabolomics limitations. This study aimed to optimize the staged solid-state fermentation (SSF) system for maximum antibacterial activity, verify the triple-microbial consortium’s synergistic enhancement effect, and elucidate the dynamic metabolic mechanism via time-series metabolomics. A staged SSF strategy was established: Aspergillus niger monoculture (0–48 h) followed by Bacillus subtilis and Saccharomyces cerevisiae co-culture (48–72 h). Key parameters were optimized via single-factor experiments and a Box–Behnken design. Under optimal conditions, inhibition zones against Staphylococcus aureus and Escherichia coli reached 20.8 ± 0.3 mm and 17.6 ± 0.2 mm, respectively, with a 17.5% increase in S. aureus inhibition and markedly improved E. coli inter-batch consistency. Time-series untargeted LC-MS/MS metabolomics (2681 identified metabolites) revealed a three-stage metabolic relay model driving antibacterial enhancement: 0–48 h shikimate pathway activation for phenolic precursor accumulation; 48–60 h dipeptide conversion and ABC transporter enrichment initiating antibacterial synthesis; 60–72 h metabolic flux redirected to indole alkaloid biosynthesis for complex antibacterial compound accumulation. This work provides a mechanistic paradigm for the high-value valorization of herbal byproducts, with applications in natural antibacterial agents and functional feed additives. Full article

In this study, Chinese medicinal herbs were evaluated as potential antibiotic substitutes for Chinese soft-shelled turtle (Pelodiscus sinensis). Forty-five herbs were initially screened for antibacterial activity against Salmonella enteritidis, Escherichia coli, and Shigella flexneri. Nine herbs exhibiting broad-spectrum inhibitory effects were selected and subjected to microbial fermentation, after which their antibacterial activities were reassessed and applied as dietary supplements in feeding trials. The results showed that fermentation altered the antibacterial activities of several herbs and enhanced their overall functional performance. Dietary supplementation with fermented Chinese herbal medicine did not adversely affect feed utilization but significantly improved hematological parameters, liver and kidney function indicators, antioxidant capacity, and nonspecific immune responses. Furthermore, turtles fed fermented herbal diets exhibited higher survival rates following bacterial challenge. Intestinal microbiota analysis based on 16S rRNA gene sequencing indicated that fermented herbal supplementation modulated microbial community structure by reducing potential pathogens and increasing beneficial bacterial taxa associated with intestinal health. These findings suggest that microbial fermentation effectively enhances the biological efficacy of Chinese medicinal herbs. Fermented herbal feed additives represent a promising green alternative to antibiotics for soft-shelled turtle aquaculture. The global ban on prophylactic antibiotics drives the need for safe, effective feed alternatives. Microbial fermentation of Chinese herbs (FCM) is proposed to enhance efficacy and detoxification, but its comprehensive effects in aquaculture require deeper investigation. This study evaluated compound unfermented (CM) and fermented (FCM) Chinese herbal supplements on the Chinese soft-shelled turtle (Pelodiscus sinensis). Initial screening showed fermentation generally enhanced the antibacterial activity of the herbs against common enteric pathogens (S. enteritidis, E. coli, S. flexneri). Results indicated that the FCM diet significantly improved physiological status, leading to higher red blood cell counts, better liver/kidney function (reduced ALT/AST, UREA), and stronger immune/antioxidant responses (increased Lysozyme and T-AOC) compared to CM or control diets. Critically, the FCM group achieved the highest survival rates across all single and combined pathogen challenges, demonstrating superior protective efficacy. Furthermore, FCM effectively modulated the gut microbiota, enriching beneficial fermentative bacteria. In conclusion, microbial fermentation significantly amplifies the health-promoting and protective benefits of Chinese herbal supplements in soft-shelled turtles, positioning FCM as a promising green alternative for disease control in aquaculture. Full article

Chinese herbal medicine is rich in active ingredients that can promote growth and enhance immune function. In this study, Lycium barbarum, Panax ginseng, Astragalus membranaceus and Phragmitis rhizoma were crushed and mixed to prepare a compound Chinese herbal medicine. The basic feed of Megalobrama amblycephala was supplemented with 0 (control group), 1% (T1), 2% (T2) and 4% (T3) of this compound medicine. After raising for 90 days, in the T1 and T2 experimental groups, the length and width of intestinal villi and the activities of amylase, trypsin and lipase in the intestine were significantly higher than those in the control group. The weight gain rate and specific growth rates were highest and the feed coefficient was lowest in the T2 experimental group. In the control group, a large number of dilated hepatic sinusoids were detected, while this number significantly decreased in the T1 experimental group and they were not detected at all in the T2 and T3 experimental groups. The spleen and liver body indices were highest in the T2 experimental group. In all experimental groups, the Lys content and the activities of T-SOD, CAT, ACP, AKP and GSH-PX in serum were significantly higher than those of the control group. The expression of IgM, C3, TNF-ɑ and IL-1β in the head kidney; C3, TNF-ɑ and IL-1β in the spleen; C3 and IL-1β in the gills; IgM, C3 and IL-1β in liver; and IL-1β in the intestine was highest in the T2 experimental group. After challenge with Aeromonas hydrophila, the cumulative mortality rate of M. amblycephala was lowest in the T2 experimental group. The results of this study indicated that this compound Chinese herbal medicine could significantly enhance immunity, increase the activity of intestinal digestion-related enzymes and promote the growth of M. amblycephala. The appropriate addition amount of this compound Chinese herbal medicine in the basic feed of M. amblycephala was 2%. Full article

Climate change exerts an increasing impact on the health and resilience of honey bees through a combination of rising temperatures, altered precipitation patterns, and intensified parasitic and infectious pressure. The present study aims to analyze climatic conditions in Bulgaria for the period 2021–2024 and to evaluate the results of a national survey conducted among beekeepers, focusing on winter colony losses during the 2023/2024 season and the feeding strategies applied. The survey was carried out in 2024 among 70 beekeepers from 20 administrative regions of the country, managing a total of 8935 bee colonies. The data were analyzed using descriptive statistics and stratified by region. The reported average winter mortality was 2.22% (198 colonies), with pronounced territorial variability. The most frequently indicated self-reported probable cause of losses was bee diseases, with varroosis identified as the dominant factor. Analysis of management practices revealed widespread application of combined feeding schemes based on plant-derived supplementary feeds, primarily administered in spring (March–April) and late summer (August–September). The obtained results differ from published national data for 2024, according to which total colony losses reached 16.3%, while losses associated with mortality or severe demographic collapse accounted for 11.6%. Despite the limitations inherent to the survey-based approach and self-reported data, the results suggest that integrated management combining parasite control with targeted nutritional support through the use of Bulgarian herbal supplementary feeds may coincide with the winter survival patterns reported within the surveyed sample. Full article

The present study aimed to evaluate the effects of fermented compound Chinese herbal medicine (FCHM, Vaccaria segetali, Tetrapanax papyriferus, Ligusticum chuanxiong Hort and Rhaponticum uniflorum) on the reproductive performance of Ningxiang sows. A total of 30 Ningxiang sows were randomly assigned to the control group (CON), CHM group, and FCHM group. The results indicated that dietary CHMs and FCHM supplementation significantly increased (p < 0.05) the milk production, feed intake, reproductive performance protein content, and lactose content in the milk of sows and significantly decreased (p < 0.05) the number of somatic cells in colostrum and in the number of low-birthweight piglets. Dietary FCHM supplementation significantly increased (p < 0.05) the number of healthy piglets, birth litter weight, colostrum fat content, and feed intake. Moreover, malondialdehyde, porcine interleukin-1α, and porcine interleukin-6 in sow serum were decreased (p < 0.05), and the activity of superoxide dismutase, total antioxidant capacity, immunoglobulin, prolactin and progesterone levels (p < 0.05) were increased, with FCHM supplementation. The colostrum metabolomics analyses showed that FCHM significantly enriched the oxytocin signaling pathway, calcium signaling pathway, and pathways associated with milk composition synthesis. In conclusion, supplementing with FCHM improved the reproductive performance and milk metabolic biomarkers of sows and may serve as an effective feed additive to improve productivity. Full article

This study evaluated the effects of dietary fermented Chinese herbal waste compound (FCHW, comprising fermented stems and leaves of Astragalus membranaceus, Rheum tanguticum, and Bupleurum chinense) on the growth, digestive function, antioxidative capacity, and non-specific immunity in juvenile largemouth bass (Micropterus salmoides). Fish were randomly assigned to one of three dietary treatments for 45 days: a basal diet (control), a basal diet supplemented with 1% Chinese herbal waste (CHW), and a basal diet supplemented with 1% FCHW. The results showed that, compared to the control group, dietary FCHW significantly enhanced weight gain rate (WGR), specific growth rate (SGR), hepatic antioxidant enzyme activities (SOD, CAT, and GSH-Px), and hepatic non-specific immune parameters (ACP and AKP activities) of M. salmoides on both day 30 and day 45 (p < 0.05) except CAT activity on day 30. FCHW supplementation also significantly increased intestinal villus height, width, and muscularis thickness at both time points (p < 0.05). However, intestinal digestive enzyme activities (trypsin, lipase, and amylase) were elevated significantly only on day 30 relative to the control (p < 0.05). Dietary CHW showed limited efficacy. Compared to the control group, dietary CHW supplementation significantly improved intestinal lipase activity and hepatic SOD activity on day 30 (p < 0.05). By day 45, dietary CHW supplementation significantly increased intestinal morphology (villus height, width, and muscularis thickness) (p < 0.05). These results indicate that fermentation enhances the bioactivity of CHW, thereby supporting the potential of FCHW as a functional feed additive in aquaculture. Full article

Climate change and global warming are concerning issues impacting various industries. In the aquaculture industry, these issues are more important in coldwater species, like rainbow trout Oncorhynchus mykiss. Hence, strategies to control these negative effects are worthy of study. Herbal feed additives are reliable tools to increase fish growth and health, thereby mitigating the drawbacks of climate change on fish. In this study, three diets containing 100 (100EO), 200 (200EO), and 400 (400EO) mg/kg essential oil of Abies sibirica (SBF) along with a control diet (CTL; unsupplemented) were fed to triplicate groups of fish for 60 days. Then the fish were exposed to a 96 h heat stress (25 °C) to monitor their survival and biochemical responses. The results showed that growth performance, feed efficiency, heat stress resistance, intestinal activity of digestive enzymes, and skin mucus immunological parameters significantly (p < 0.05) increased in the SBF essential oil treatments, and the highest increases were observed in the 100EO treatment, followed by the 200EO group. Dietary supplementation with SBF essential oil significantly (p < 0.05) mitigated heat stress-induced increases in plasma cortisol and glucose. Moreover, dietary SBF essential oil significantly (p < 0.05) enhanced immunological parameters such as plasma and intestinal lysozyme and immunoglobulin levels, and improved hepatic antioxidant defenses (including catalase, glutathione peroxidase, total antioxidant capacity, and reduced glutathione), while reducing lipid peroxidation. These effects were most pronounced in the 100EO and 200EO treatments, with the highest performance being observed in the former group. In conclusion, dietary SBF essential oil at 100 mg/kg is capable of augmenting growth performance, immunity, and antioxidant capacity, and suppressing physiological stress, thereby augmenting fish resilience against heat stress. Full article

The relationships between mycotoxins content in food commodities or feedstuffs and the foodborne diseases is well known. So far, the available data mainly include chemical methods of mycotoxins decontamination for agricultural commodities or raw materials, including mycotoxin binders. Therefore, the possible use of some natural and cost-effective supplements such as herbs, fungi, microorganisms, or plants with powerful and safe protection against mycotoxin-induced health ailments is the main subject of this review paper. Various antagonistic microorganisms or yeast with fungicidal properties, as well as some herbs or plants that suppress fungal development and the subsequent production of target mycotoxins and/or have protective effect against mycotoxins, are deeply studied in the literature, and practical suggestions are given in this regard. The protection by degradation, biotransformation, or binding of mycotoxins by using natural additives such as herbs or plants to feedstuffs or foods has also been thoroughly investigated and analyzed as a possible approach for ameliorating the target adverse effects of mycotoxins. Possible beneficial dietary changes have also been studied to potentially alleviate mycotoxin toxicity. Practical advice are provided for possible application of the same natural supplements in real-life practice for combating mycotoxin-induced health ailments. Natural feed supplements and bioactive compounds appeared to be safe emerging approaches to preventing health ailments caused by mycotoxins. However, the available data mainly address some in vitro studies, and more in vivo experiments are necessary for introducing such approaches in the real-life practice or industry. Generally, target herbal supplements, antioxidants, or polyenzyme complements could be used as powerful protectors in addition to natural mycotoxin binders. Bioactive agents and enzymatic degradation are reported to be very successful in regard to PAT and OTA, whereas antagonistic microorganisms/fungi/yeasts have a successful application against AFs and PAT-producing fungi. Full article

Objectives: Ferulic acid is a natural and safe herbal feed additive. This study aims to evaluate the effects of ferulic acid on the growth performance, anti-inflammatory and antioxidant capacities, immune function, and intestinal microbiota of broiler chickens. Methods: A total of 320 broiler chickens, aged 14 days, were randomly divided into four groups: a blank control group (MA group), a low-concentration ferulic acid group (BM group, 10 mg/kg), a medium-concentration ferulic acid group (CM group, 30 mg/kg), and a high-concentration ferulic acid group (DM group, 90 mg/kg) after a 14-day acclimatization period. The experiment lasted for 28 days, and the chickens were dissected on day 29. Results: The results showed that compared to the MA group, the feed-to-meat ratio in the CM and DM groups was significantly reduced. The activity of duodenal trypsin in the CM and DM groups was significantly enhanced, and the activity of pancreatic protease in the DM group was significantly increased. The serum levels of urea nitrogen, creatinine, and triglycerides were significantly elevated in the CM and DM groups. The serum malondialdehyde (MDA) levels in the BM, CM, and DM groups were significantly reduced, while the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were significantly increased in the CM and DM groups. The serum interleukin-2 (IL-2) levels in the BM group were significantly decreased, while interferon-gamma (IFN-γ) levels in the CM group and complement component 3 (C-3) levels in the DM group were significantly increased. The mRNA expression levels of TLR4, MyD88, NF-κB, TNF-α, NLRP3, IL-1β, and IL-18 in the jejunum of the DM group were significantly reduced. The diversity of cecal microbiota in the ferulic acid groups changed, with a certain degree of increase in the relative abundance of Spirulina and Ruminococcus. The relative abundance of Escherichia coli in the DM group significantly increased, altering the metabolic function of the cecal microbiota in broiler chickens. Conclusions: The above results indicate that ferulic acid, as a novel feed additive for broiler chickens, has an impact on the growth performance, anti-inflammatory and antioxidant capacity, immune function, and intestinal microbiota of broiler chickens. Full article

A study was designed to explore the possibility of using herbal supplementation to sustain growth performance during heat stress exposure in Kenguri sheep. This 60-day study was conducted on 24 Kenguri ewes (1–2 years old), randomly assigned to four treatment groups (n = 6 per group) as follows: KC (n = 6; Kenguri Control), KHS (n = 6; Kenguri Heat Stress), KCS (n = 6; Kenguri Control and herbal supplement), and KHSS (n = 6; Kenguri Heat Stress and herbal supplement). The herbal mixture of Ocimum sanctum (Tulsi), Emblica officinalis (Amla), Morinda citrifolia (Noni), Withania somnifera (Ashwagandha), and Phyllostachys edulis (Bamboo) was used in this study. The herbal supplement used in the present study was given to the KCS and KHSS groups’ animals in dry powder form at a dose of 0.8 g/Kg BW/Day. All variables were recorded fortnightly, and gene expression analysis was performed at the end of the experiment. The results indicated that the recorded temperature–humidity index (THI) provided thermal comfort for KC and KCS while inducing extremely severe heat stress to the KHS and KHSS groups. Heat stress did not alter the feed intake, while the herbal supplement during heat stress increased the feed intake from day 30 onwards. Furthermore, heat stress significantly (p < 0.001) increased the water intake, while the herbal supplement did not alter the heat stress-induced water intake. In addition, neither heat stress nor herbal supplements influenced the body weight and allometric measurements studied. Furthermore, heat stress significantly (p < 0.01) decreased the level of plasma tri-iodo-thyronine (T₃) and thyroxin (T₄) and had a non-significant effect on plasma growth hormone (GH), insulin-like growth factor-1 (IGF-1), while the herbal supplements significantly (p < 0.01) increased the levels of all these hormones studied. Likewise, in peripheral blood mononuclear cells (PBMCs) the expression patterns of growth hormone receptor (GHR), Insulin-like growth factor 1 (IGF1) and prolactin receptor (PRLR) were significantly (p < 0.001) downregulated during heat stress (0.25, 0.3, and 0.48-fold change, respectively). However, the herbal supplement significantly (p < 0.01) increased the heat stress-induced reduction in the expression pattern of these three genes (0.65, 0.61, and 0.61-fold change, respectively). Therefore, from this study, it could be concluded that although the herbal supplements did not bring positive changes in body weight and allometric measurements, it still had a beneficial impact on the endocrinology and genes governing growth performance in Kenguri ewes. Thus, the herbal feed additive used in the study shows promise for relieving heat stress in Kenguri ewes. Full article