Nutrient digestibility in black soldier fly larva was greater than in adults for pigs and could be estimated using fiber.

The objectives of the present study were to determine the nutrient digestibility of fish meal, defatted black soldier fly larvae (BSFL), and adult flies and to develop equations for estimating in vitro nutrient digestibility of BSFL for pigs. in vitro digestion procedures were employed to mimic the digestion and absorption of nutrients in the pig intestine. Correlation coefficients between chemical composition and in vitro nutrient digestibility of BSFL were calculated. In Exp. 1, in vitro ileal digestibility (IVID) of dry matter (DM) and crude protein (CP) and in vitro total tract digestibility (IVTTD) of DM and organic matter in defatted BSFL meal were less (p < 0.05) than those in fish meal but were greater (p < 0.05) than those in adult flies. In Exp. 2, CP concentrations in BSFL were negatively correlated with ether extract (r = -0.91) concentration but positively correlated with acid detergent fiber (ADF; r = 0.98) and chitin (r = 0.95) concentrations. ADF and chitin concentrations in BSFL were negatively correlated with IVID of DM (r = -0.98 and -0.88) and IVTTD of DM (r = -1.00 and -0.94) and organic matter (r = -0.99 and -0.98). Prediction equations for in vitro nutrient digestibility of BSFL were developed: IVID of CP (%) = -0.95 × ADF (% DM) + 95 (r2 = 0.75 and p = 0.058) and IVTTD of DM (%) = -2.09 × ADF + 113 (r2 = 0.99 and p < 0.001). The present in vitro experiments suggest that defatted BSFL meal was less digestible than fish meal but was more digestible than adult flies, and nutrient digestibility of BSFL can be predicted using ADF as an independent variable.

Black soldier fly (Hermetia illucens) larvae oil as an alternative fat ingredient to soybean oil in laying hen diets.

OBJECTIVE: The objective of this study was to determine whether dietary black soldier fly (Hermetia illucens, HI) larvae oil (HILO) could serve as an alternative fat source to soybean oil (SBO) in laying hen diets. METHODS: We randomly assigned 25-week-old Hy-line Brown laying hens (n = 144) to receive (n = 6 hens/group; eight replicates) a control or an experimental diet in which SBO was replaced with 50% (50HILO) or 100% HILO (100HILO). RESULTS: Dietary HILO did not negatively affect body weight or productive performance during the study. The eggs also had similar quality parameters, proximate composition, and cholesterol levels. However, the yolk color index was significantly higher (p<0.01) in the 100HILO than in the other groups. Dietary HILO significantly altered the composition of fatty acids (FAs) in abdominal fat and eggs. Total saturated fatty acids (SFAs) and total polyunsaturated FAs (PUFAs) were significantly increased and decreased in the 50HILO and 100HILO groups, respectively, compared with those in the control group (p<0.001 and p<0.0001, respectively). Specifically, the medium-chain FAs lauric and myristic acids were remarkably increased in the abdominal fat of laying hens fed HILO (p<0.0001), whereas only myristic acid increased in eggs (p<0.0001). Undesirable heavy metal (aluminum, fluorine, arsenic, lead, mercury, and cadmium) concentrations were below permissible limits in eggs. CONCLUSION: We considered that HILO could be an alternative dietary fat to SBO for laying hens with maintained productive performance and good egg quality.

Effect of Flutriafol Exposure on Residue Characteristics in Pig Muscle and Fat Tissue.

This study investigated the effect of exposure to flutriafol based on residues in pigs. Pigs were exposed to different concentrations (0.313, 0.625, 3.125, 6.25, and 12.5 mg/kg bw/d, n=20) for 4 wk in different treatment groups. Serum biochemical analysis, residue levels, and histological analysis were conducted using the VetTest chemistry analyzer, liquid chromatography mass spectrometry, and Masson's trichrome staining, respectively. The body weight (initial and final) was not significantly different between groups. Parameters such as creatinine, blood urea nitrogen, alanine aminotransferase, and lipase levels were significantly different as compared to the control group. Flutriafol increased the residue limits in individual tissue of the pigs in a dose dependent manner. Flutriafol exposures indicated the presence of fibrosis, as confirmed from Masson's trichrome staining. These results suggest that flutriafol affects the morphology and serum levels in pigs. The dietary flutriafol levels can provide a basis for maximum residue limits and food safety for pork and related products.

Additivity of digestible energy and nutrient concentrations in hatchery byproducts fed to nursery pigs.

OBJECTIVE: The objective was to test additivity of digestible energy and nutrient concentrations in the hatchery byproduct mixture fed to nursery pigs. METHODS: In the previous studies, energy, phosphorus, calcium, and amino acid digestibility of infertile eggs, unhatched eggs, culled chicks, and a mixture of 3 hatchery byproduct ingredients was determined in nursery pigs (initial body weight = 9.4 to 14.2 kg). An additivity test was conducted using these determined values. RESULTS: No difference was observed between determined and predicted metabolizable energy values in the mixture (3,998 and 3,990 kcal/kg as-is basis, respectively). Measured standardized total tract digestible phosphorus in the mixture was less than the predicted value (4.5 vs 5.3 g/kg as-is basis, respectively; p<0.05). Measured standardized total tract digestible calcium in the mixture was greater compared with the predicted value (40.0 vs 31.7 g/kg as-is basis, respectively; p<0.05). Measured standardized ileal digestible tryptophan in the mixture was greater than the predicted value (3.7 vs 3.1 g/kg as-is basis, respectively; p<0.05) whereas other amino acid values were additive. CONCLUSION: Energy and most of amino acid concentrations in hatchery byproducts are additive in the mixture fed to nursery pigs.

Effects of Dietary Supplementation of Black Soldier Fly (Hermetia illucens) Larvae Oil on Broiler Health.

Insects are a potential source of proteins and fats which can be incorporated into diets of broiler chickens. Accordingly, black soldier fly larvae oil (BSFLO) needs to be tested as an appropriate fat source to produce healthy chickens for consumers. Therefore, the objective of the present study was to evaluate the effects of the replacement of soybean oil (SBO) with BSFLO in broiler diets on intestinal health and blood profiles. A total of 210 one-day-old male broilers were randomly allocated to three dietary treatments (10 replicates of seven birds per group): a control diet and two experimental diets in which SBO was replaced with 50% (50 BSFLO) or 100% (100 BSFLO) BSFLO. At the end of the study (35 days), 18 birds (six broilers per treatment) were slaughtered to determine the intestinal morphology, digestibility, and volatile fatty acid (VFA) profile. Blood samples were collected from 24 randomly selected birds (eight broilers per treatment) to determine the blood profiles. BSFLO supplementation positively affected villus height but did not affect digestibility. BSFLO showed no adverse effects on the VFA and blood profiles. In conclusion, the results of this study suggest that SBO can be replaced by BSFLO without any adverse effects on broiler health.

Effect of Pesticide Residue in Muscle and Fat Tissue of Pigs Treated with Propiconazole.

This study estimated the effect of exposure to propiconazole through implementation and residues in finishing pigs. We analyzed the expression of fibrosis-related genes and performed histological analysis of the blood, liver, kidney, muscle, ileum, and fat tissues. The animals were exposed for 28 d to different concentrations of propiconazole (0.09, 0.44, 0.88, 4.41, and 8.82 mg/kg bw/d). Quantitative, gene expression, and histological analyses in tissues were performed using liquid chromatography mass spectrometry, real-time PCR, and Masson's trichrome staining, respectively. Final body weight did not differ among groups. However, genes involved in fibrosis were significantly differentially regulated in response to propiconazole concentrations. Glucose, alanine aminotransferase, and total bilirubin levels were significantly increased compared with those in the control group, while alkaline phosphatase level was decreased (p<0.05) after exposure to propiconazole. The residue limits of propiconazole were increased in the finishing phase at 4.41 and 8.82 mg/kg bw/d. The liver, kidney, and ileum showed blue staining after propiconazole treatment, confirmed by Masson's trichrome staining. In conclusion, these findings suggest that propiconazole exposure disturbs the expression of fibrosis-related genes. This study on dietary propiconazole in pigs can provide a basis for determining maximum residue limits and a better understanding of metabolism in pigs and meat products.

Energy concentration and phosphorus digestibility in meat meal, fish meal, and soybean meal fed to pigs.

OBJECTIVE: The objectives of the present study were to determine digestible energy (DE), metabolizable energy (ME), and standardized total tract digestibility (STTD) of phosphorus (P) in meat meal (MM) and to compare these values with those in fish meal (FM), and soybean meal (SBM) fed to pigs. METHODS: Two experiments were conducted to determine energy concentrations and STTD of P in MM, FM, and SBM fed to growing pigs. In Exp. 1, DE and ME in the 3 test ingredients were measured using 24 barrows with initial body weight (BW) of 77.7±8.3 kg. A corn-based diet and 3 diets containing corn and 22% to 30% of each test ingredient were prepared. In Exp. 2, the STTD of P in the 3 test ingredients was measured using 24 barrows (90.9±6.6 kg BW). Three diets were formulated to contain each test ingredient as the sole source of P. RESULTS: In Exp. 1, the DE and ME values in MM (3,310 and 2,856 kcal/kg dry matter [DM]) were less (p<0.05) than those in FM (4,121 and 3,572 kcal/kg DM) and SBM (4,390 and 4,032 kcal/kg DM). In Exp. 2, FM (64.3%) had greater (p<0.05) STTD of P than SBM (44.8%) with MM (55.8%) having intermediate STTD of P. CONCLUSION: The MM contains less energy concentrations compared with FM and SBM, and digestibility of phosphorus in MM does not differ from that in FM and SBM.

Effects of recovery from short-term heat stress exposure on feed intake, plasma amino acid profiles, and metabolites in growing pigs.

Heat stress (HS) damages health and decreases performance variables in pigs, and if severe enough, causes mortality. However, metabolic changes under HS and recovery following HS are poorly understood. Therefore, this study was aimed to expose the essential mechanisms by which growing pigs respond to HS and the temporal pattern of plasma concentrations (PC) of amino acids (AAs) and metabolites. Crossbred male growing pigs were penned separately and allowed to adapt to thermal-neutral (TN) conditions (20°C and 80% relative humidity; TN[-1D]). On the first day, all pigs were exposed to HS for 24 h (36°C and 60% relative humidity), then to TN conditions for 5 days (TN[2D] to TN[5D]). All pigs had ad libitum access to water and 3 kg feed twice daily. Rectal temperature (RT) and feed intake (FI) were determined daily. HS pigs had higher RT (40.72°C) and lower (50%) FI than TN(-1D) pigs (p < 0.01). The PC of indispensable (threonine, valine, and methionine) and dispensable (cysteine and tyrosine) AAs were higher (p < 0.05) in HS than TN(-1D) pigs and remained increased during recovery time. Nonprotein α-aminobutyric acid and ß-alanine concentrations were higher (p < 0.05) in HS than TN(-1D) pigs. The metabolite concentration of creatinine was higher (p < 0.01) under HS treatment than other treatments, but that of alanine and leucine remained increased (p < 0.05) through 5 d of recovery. In summary, some major differences were found in plasma AA profiles and metabolites between HS- and TN-condition pigs. This indicates that the HS pigs were forced to alter their metabolism, and these results provide information about mechanisms of acute HS responses relative to the recovery time.

Effects of Dietary Inclusion Level of Microwave-Dried and Press-Defatted Black Soldier Fly (Hermetia illucens) Larvae Meal on Productive Performance, Cecal Volatile Fatty Acid Profile, and Egg Quality in Laying Hens.

Black soldier fly (Hermetia illucens) larvae meal (HILM) is a promising alternative to soybean meal (SBM). However, little information is available on the effect of microwave-dried HILM as a dietary protein source in the diets of laying hens. We studied the effect of dietary inclusion level of microwave-dried HILM on productive performance, cecal volatile fatty acid profile, egg quality, overall fatty acid profile, and heavy metal residues of the egg in laying hens. A total of 144 laying hens (25-week-old) were randomly assigned to three dietary groups (eight replicates and six birds/cage): a control diet, and two experimental diets in which SBM was replaced with 2% HILM (2HILM) and 4% HILM (4HILM). The laying hens that fed the HILM showed satisfactory results in productive performance and egg quality. Branched-chain fatty acid levels increased linearly (p < 0.001) with dietary treatment in the cecal digesta. Total monounsaturated fatty acid increased linearly (p < 0.01), while total polyunsaturated fatty acid decreased linearly (p < 0.01) in the eggs by dietary treatments. Heavy metals, magnesium, zinc, and aluminum were increased linearly with dietary treatment; however, undesirable heavy metals were under permissible levels. Thus, microwave-dried HILM could be a possible alternative to SBM in the diets of laying hens; however, improvements in fatty acid profile are needed.

Effects of acute heat stress on salivary metabolites in growing pigs: an analysis using nuclear magnetic resonance-based metabolomics profiling.

Heat stress (HS) causes adverse impacts on pig production and health. A potential biomarker of HS is required to predict its occurrence and thereby better manage pigs under HS. Information about the saliva metabolome in heat-stressed pigs is limited. Therefore, this study was aimed to investigate the effects of acute HS on the saliva metabolome and identify metabolites that could be used as potential biomarkers. Growing pigs (n = 6, 3 boars, and 3 gilts) were raised in a thermal neutral (TN; 25°C) environment for a 5-d adaptation period (CON). After adaptation, the pigs were first exposed to HS (30°C; HS30) and then exposed to higher HS (33°C; HS33) for 24 h. Saliva was collected after adaptation, first HS, and second HS, respectively, for metabolomic analysis using 1H-nuclear magnetic resonance spectroscopy. Four metabolites had significantly variable importance in the projection (VIP > 1; p < 0.05) different levels in TN compared to HS groups from all genders (boars and gilts). However, sex-specific characteristics affected metabolites (glutamate and leucine) by showing the opposite results, indicating that HS was less severe in females than in males. A decrease in creatine levels in males and an increase in creatine phosphate levels in females would have contributed to a protective effect from protein degradation by muscle damage. The results showed that HS led to an alteration in metabolites related to energy and protein. Protection from muscle damage may be attributed to the alteration in protein-related metabolites. However, energy-related metabolites showed opposing results according to sex-specific characteristics, such as sex hormone levels and subcutaneous fat layer. This study had shown that saliva samples could be used as a noninvasive method to evaluate heat-stressed pigs. And the results in this study could be contributed to the development of a diagnostic tool as a noninvasive biomarker for managing heat-stressed pigs.

Effects of Dietary Inclusion Level of Microwave-Dried and Press-Defatted Black Soldier Fly (Hermetia illucens) Larvae Meal on Carcass Traits and Meat Quality in Broilers.

Limited information is available regarding the use of microwave-dried Hermetia illucens larvae meal (HILM) as a dietary protein source for broiler diets. Therefore, we investigated the effects of microwave-dried HILM on carcass traits, meat quality, fatty acid (FA) profiles of abdominal fat and meat, and heavy metal residues of the meat in broilers. A total of 126 male broilers were randomly assigned to three dietary treatment groups (6 replicates and 7 birds/pen): a control diet and two experimental diets in which soybean meal was replaced with 25 or 50% HILM. The broilers were slaughtered at 35 days; the carcasses were weighed, and breast and leg meats were excised from 12 birds per treatment (2 birds/pen) for meat analysis. The breast meat quality and proximate composition showed satisfactory results. For the higher HILM diet, the content of saturated FA in the abdominal fat was increased and that of polyunsaturated FA was decreased (p < 0.001); the FA profile of leg meat did not significantly differ between groups. The concentrations of undesirable heavy metals in the HILM and leg meat were below permissible levels. However, the carcass weight was decreased (p < 0.001) in the 50% HILM group. Microwave-dried HILM is a potential ingredient for broiler diets, with up to 25% substitution showing no detrimental effects on carcass traits, meat quality, FA profiles, and heavy metal residues in the meat.

Effect of commercially purified deoxynivalenol and zearalenone mycotoxins on microbial diversity of pig cecum contents.

OBJECTIVE: Deoxynivalenol (DON) and zearalenone (ZEN) are mycotoxins that frequently contaminate maize and grain cereals, imposing risks to the health of both humans and animals and leading to economic losses. The gut microbiome has been shown to help combat the effects of such toxins, with certain microorganisms reported to contribute significantly to the detoxification process. METHODS: We examined the cecum contents of three different dietary groups of pigs (control, as well as diets contaminated with 8 mg DON/kg feed or 0.8 mg ZEN/kg feed). Bacterial 16S rRNA gene amplicons were acquired from the cecum contents and evaluated by next-generation sequencing. RESULTS: A total of 2,539,288 sequences were generated with ~500 nucleotide read lengths. Firmicutes, Bacteroidetes, and Proteobacteria were the dominant phyla, occupying more than 96% of all three groups. Lactobacillus, Bacteroides, Megasphaera, and Campylobacter showed potential as biomarkers for each group. Particularly, Lactobacillus and Bacteroides were more abundant in the DON and ZEN groups than in the control. Additionally, 52,414 operational taxonomic units were detected in the three groups; those of Bacteroides, Lactobacillus, Campylobacter, and Prevotella were most dominant and significantly varied between groups. Hence, contamination of feed by DON and ZEN affected the cecum microbiota, while Lactobacillus and Bacteroides were highly abundant and positively influenced the host physiology. CONCLUSION: Lactobacillus and Bacteroides play key roles in the process of detoxification and improving the immune response. We, therefore, believe that these results may be useful for determining whether disturbances in the intestinal microflora, such as the toxic effects of DON and ZEN, can be treated by modulating the intestinal bacterial flora.

Excessive dietary lead reduces growth performance and increases lead accumulation in pigs.

OBJECTIVE: The objective of this study was to investigate the influence of dietary lead (Pb) supplementation and feeding period on growth performance, organ weight, and Pb accumulation in pigs. METHODS: In a 56-day feeding experiment, a total of 48 barrows with initial body weight 10.4±0.6 kg were allotted to 2 dietary treatments (0 and 200 mg/kg of supplemental Pb) in a completely randomized design with 6 replicates. Body weight and feed intake were recorded to calculate growth performance. At the end of each 14 day-period (on days 14, 28, 42, and 56), an animal was randomly selected from each pen and slaughtered to collect blood samples, hair samples, left 5th rib, heart, liver, kidneys, lungs, and longissimus dorsi muscle samples. RESULTS: Average daily gain and average daily feed intake were reduced (p<0.05) by supplemental Pb during the day 42 to 56. Relative kidney weight to body weight was linearly increased with increasing feeding period in pigs fed the Pb-supplemented diet, but not in pigs fed the control diet (p<0.05). The Pb concentrations in hair, left 5th rib, kidneys, and lungs were linearly increased with longer feeding period in pigs fed the Pb-supplemented diet, but not in pigs fed the control diet (p<0.01). CONCLUSION: Dietary Pb supplementation caused growth retardation and Pb accumulation in most organs, particularly in hair, bone, and kidneys in a time-dependent manner.

Metabolomics Analysis of the Beef Samples with Different Meat Qualities and Tastes.

The purpose of this study was to investigate the meat metabolite profiles related to differences in beef quality attributes (i.e., high-marbled and low-marbled groups) using nuclear magnetic resonance (NMR) spectroscopy. The beef of different marbling scores showed significant differences in water content and fat content. High-marbled meat had mainly higher taste compounds than low-marbled meat. Metabolite analysis showed differences between two marbling groups based on partial least square discriminant analysis (PLS-DA). Metabolites identified by PLS-DA, such as N,N-dimethylglycine, creatine, lactate, carnosine, carnitine, sn-glycero-3-phosphocholine, betaine, glycine, glucose, alanine, tryptophan, methionine, taurine, tyrosine, could be directly linked to marbling groups. Metabolites from variable importance in projection plots were identified and estimated high sensitivity as candidate markers for beef quality attributes. These potential markers were involved in beef taste-related pathways including carbohydrate and amino acid metabolism. Among these metabolites, carnosine, creatine, glucose, and lactate had significantly higher in high-marbled meat compared to low-marbled meat (p<0.05). Therefore, these results will provide an important understanding of the roles of taste-related metabolites in beef quality attributes. Our findings suggest that metabolomics analysis of taste compounds and meat quality may be a powerful method for the discovery of novel biomarkers underlying the quality of beef products.

Nuclear magnetic resonance-based metabolomics analysis and characteristics of beef in different fattening periods.

Beef quality is influenced by the fattening period. Therefore, meat metabolomics profiles from the different fattening periods (e.g., short-term vs. long-term) were analyzed for identify potential indicators using nuclear magnetic resonance. Additionally, blood, free fatty acid, sensory, and mineral compositions in Korean steers were determined. Blood, free fatty acid, and mineral concentrations showed significant differences between short-term and long-term groups that were fed different diets. However, there were no sensory differences in the two fattening groups. Additionally, the metabolic profiles of meats were clearly separated based on multivariate orthogonal partial least square discriminant analysis. Six metabolites of variable importance in the projection plot were identified and showed high sensitivity as candidate markers for meat characteristics. In particular, lactate, carnosine, and creatine could be directly linked to scientific indicators of the fattening stage (31 vs. 28 mo) of meat. Our findings suggest that the metabolomics approach could be a powerful method for the detection of novel signatures underlying the managing period of beef.

Genome-Wide Transcriptome and Metabolome Analyses Provide Novel Insights and Suggest a Sex-Specific Response to Heat Stress in Pigs.

Heat stress (HS) negatively impacts pig production and swine health. Therefore, to understand the genetic and metabolic responses of pigs to HS, we used RNA-Seq and high resolution magic angle spinning (HR-MAS) NMR analyses to compare the transcriptomes and metabolomes of Duroc pigs (n = 6, 3 barrows and 3 gilts) exposed to heat stress (33 °C and 60% RH) with a control group (25 °C and 60% RH). HS resulted in the differential expression of 552 (236 up, 316 down) and 879 (540 up, 339 down) genes and significant enrichment of 30 and 31 plasma metabolites in female and male pigs, respectively. Apoptosis, response to heat, Toll-like receptor signaling and oxidative stress were enriched among the up-regulated genes, while negative regulation of the immune response, ATP synthesis and the ribosomal pathway were enriched among down-regulated genes. Twelve and ten metabolic pathways were found to be enriched (among them, four metabolic pathways, including arginine and proline metabolism, and three metabolic pathways, including pantothenate and CoA biosynthesis), overlapping between the transcriptome and metabolome analyses in the female and male group respectively. The limited overlap between pathways enriched with differentially expressed genes and enriched plasma metabolites between the sexes suggests a sex-specific response to HS in pigs.

Evaluation of black soldier fly larvae oil as a dietary fat source in broiler chicken diets.

The present study was conducted to evaluate the effects of black soldier fly larvae oil (BSFLO) from the black soldier fly larvae (BSFL) as a partial or total replacement of soybean oil (SBO) on growth performance, fatty acid (FA) profile, and meat quality of broiler chickens from 1 to 5 wk of age. A total of 210 male broiler chickens (Ross 308) at one-day of age were randomly allotted to 3 dietary treatments (10 replicates and 7 birds/group): a basal control diet (CON), the basal diet in which the SBO was replaced by 50% (50 BSFLO) or 100% (100 BSFLO) of BSFLO. The growth performance, physical measurements and chemical traits of leg meat, and sensory analysis of breast meat were not influenced by diets. However, the relative weight (g/kg) of gizzard of CON was significantly higher (14.85, 12.52, and 13.02 for CON, 50 BSFLO, and 100 BSFLO; p < 0.05) than that of other treatments. As expected, the FA profile of breast meat was affected by BSFLO inclusion. The proportion (%) of saturated fatty acid (SFA) was increased (27.16, 27.58, and 28.72 for CON, 50 BSFLO, and 100 BSFLO; p < 0.05) by BSFLO inclusion and the percentage (%) of MUFA was also increased (43.36, 44.58, and 48.55 for CON, 50 BSFLO, and 100 BSFLO; p < 0.01). On the contrary, the proportion (%) of PUFA was decreased (29.49, 27.84, and 22.74 for CON, 50 BSFLO, and 100 BSFLO; p < 0.01). In conclusion, the present study suggests that the replacement of BSFLO did not show an adverse effect on growth performance and it could be an ingredient as a dietary fat source for a broiler diet.

The impact of short-term acute heat stress on the rumen microbiome of Hanwoo steers.

Heat stress negatively affects cattle productivity by reducing feed intake. In the present study, we assessed if the rumen microbiome composition of Hanwoo steers was altered by exposure to heat stress. Rumen samples were collected from four Hanwoo steers that were individually housed in climate-controlled chambers with 60% humidity and environmental temperatures of: 1) 15°C (0-day group), 2) 35°C for 3 days (3-day group), and 3) 35°C for 6 days (6-day group). The total community DNA of samples was extracted, and 997,843 bacterial and 1,508,770 archaeal sequences were analyzed using next-generation sequencing. Assessment of the relative abundances revealed 15 major phyla of which Bacteroidetes was found to be the most dominant. After 3 days of heat stress exposure there were no significant changes in the rumen microbiome composition, except for a decrease in the Planctomycetes. However, after 6 days of heat stress exposure, we found that the relative abundance of fibrolytic Ruminococcaceae had decreased while that of lactate-producing Lactobacillaceae and amylolytic Prevotella and Ruminobacter had increased. The normal rumen microbiome of Hanwoo cattle was shown to be disrupted after 6 days of heat stress, which led to the decrease in fibrolytic bacteria that are sensitive to low pH and the increase in both lactate-producing and amylolytic bacteria. We have demonstrated that the microbiome composition of the rumen is affected by acute heat stress. Our findings may contribute to the development of different feeding strategies to restore heat stress-induced disruption of the rumen microbiome.

Difference of gut microbiota composition based on the body condition scores in dogs.

Microorganism residing in the gut has been known to have important roles in the animal body. Microbes and host microenvironment are highly related with host's health including energy metabolism and immune system. Moreover, it reported that gut microbiome is correlated with diseases like obesity in human and dogs. There have been many studies to identify and characterize microbes and their genes in human body. However, there was little information of microbiome in companion animals. Here, we investigated microbiota communities in feaces from twenty - four Beagles (aged 2 years old) and analyzed the taxonomy profile using metagenomics to study the difference among gut microbiome based on body condition score (BCS). gDNA was isolated from feaces, sequenced and clustered. Taxonomy profiling was performed based on the NCBI database. BCS was evaluated once a week according to the description provided by World Small Animal Veterinary Association. Firmicutes phylum was the most abundant followed by Bacteroidetes, Fusobacteria, Proteobacteria and Actinobacteria. That main microbiota in gut were differently distributed based on the BCS. Fusobacteria has been known to be associated with colon cancer in human. Interestingly, Fusobacteria was in the third level from the top in healthy dog's gut microbiome. In addition, Fusobacteria was especially higher in overweight dogs which had 6 scales of BCS. Species Fusobacterium perfoetens was also more abundant when dogs were in BCS 6. It implied that F. perfoetens would be positively related with overweight in dogs. These finding would contribute to further studies of gut microbiome and their functions to improve dog's diets and health condition.

Comparison of sample preparation procedures of inductively coupled plasma to measure elements in dog's hair.

The pre-treatment condition affects on the element analysis of inductively coupled plasma (ICP). In this study the pre-treatment condition of ICP has been studied to quantify elements in dog's hair. The hair samples were collected from twelve female Beagles by clipping them into 1 or 2 cm at the back neck. The qualitative and quantitative analysis of elements in hairs were performed by using ICP. By ICP nine elements were qualitatively detected and quantitatively analyzed (Ca, Cu, Fe, K, Mg, Na, P, Se, Zn). The measured amounts of elements were compared between 3 step and 2 step procedures which were with and without the acetone based washing step. The quantitative analysis showed that the concentrations of K, Na, P, and Se were significantly decreased in hair samples with acetone-based washing (p < 0.005 or 0.001) unlike those without the acetone-based washing. It implied that some minerals are lost by the acetone based washing during the sample preparation step. Therefore, the acetone based washing process is not suitable for quantifying elements in dog's hair. In addition, the results of qualitative and quantitative analysis were compared. Although there was a difference in absolute values of elemental contents in hair, the results of qualitative and quantitative analysis were significantly correlated each other. This finding suggested that the results of qualitative analysis can be used to monitor elemental contents in dog's hair.