Effects of Cyclic Thermal Stress at Later Age on Production Performance and Meat Quality of Fast-Growing, Medium-Growing and Thai Native Chickens

Effect of in ovo-fed amino acids on muscle and liver metabolome of broiler chickens at 24 h post-hatch

In ovo administration of amino acids has been shown to alleviate the adverse effects of heat stress on broiler chickens during the finisher phase. However, their specific influence on thermogenic organs in the early post-hatch period is not fully understood. Therefore, the aim of the present study was to explore and investigate the effects of in ovo-fed amino acids on amino acid metabolism in the liver and muscle of one-day-old broiler chicks. To achieve this, breast muscle and liver samples were taken from six randomly selected chicks per experimental group and subjected to a targeted metabolomic analysis. The experimental groups included a control group injected with 52 µL of sterile diluent/egg (CTRL), a group injected with 3.0 mg of L-Met + 2.0 mg of L-Cys/egg (T1), and a group injected with 0.4 mg of L-Leu + 1.6 mg of L-Met + 1.6 mg of L-Cys/egg (T2). The Sparse Partial Least Square - Discriminant Analysis (sPLS-DA) showed that T1 and T2 had very similar metabolomic profiles. Consequently, data from T1 and T2 were merged into a single group (Injected) for statistical analysis. Compared to CTRL, multiple pathways were significantly enriched in the muscle and liver of the Injected group. These enriched pathways included those involved in the metabolism of cysteine and methionine (FDR = 0.01), glutathione (FDR < 0.001), histidine (FDR = 0.01), taurine (FDR = 0.01), glycine, serine, and threonine (FDR = 0.01) as well as the pathway of arginine biosynthesis (FDR = 0.03). Moreover, only four muscle metabolites: homocysteine (r = -0.63, P = 0.03), S-Adenosyl-homocysteine (r = -0.62, P = 0.03), phosphocholine (r = 0.50, P = 0.01), and betaine (r = 0.52, P = 0.004), as well as four liver metabolites: phenyl pyruvic acid (r = 0.55, P = 0.02), dimethylglycine (r = 0.55, P = 0.03), phenylalanine (r = 0.50, P = 0.02), and alpha-aminobutyric acid (r = -0.53, P = 0.02) were significantly correlated with the rectal temperature of sampled chicks, suggesting a role of these metabolites in thermoregulation. In conclusion, the in ovo feeding of amino acids on embryonic day 18 was associated with the enrichment of pathways directly or indirectly involved in the response of the antioxidant defense system to oxidative stress in the liver and muscle tissues.

Rectal temperature and heat transfer dynamics in the eye, face, and breast of broiler chickens exposed to moderate heat stress

This study aimed to characterize body temperature in finishing broiler chickens and to explore heat transfer dynamics under thermoneutral (TN) and heat stress (HS) conditions. To achieve this, 900 Ross 308 chicks were divided into TN and HS groups, with the HS group subjected to cyclical heat stress (30°C, 45 % RH) from day 28 to day 33 post-hatch. Rectal temperature (Tr) and skin temperature (Ts) at the face (Tsf), eye (Tse), and breast (Tsb) were measured. Tr ranged from 39.1 to 40.6°C under TN and from 40.4 to 43.2°C under HS (Pcondition < 0.001). Core-to-skin temperature gradients were lower under HS (P < 0.0001), indicating reduced heat transfer to the skin. All Ts parameters were higher under HS (P < 0.001), and skin-to-air temperature gradients were also lower (P < 0.0001), reflecting lower heat dissipation. Ts varied significantly across anatomical regions (P < 0.001), and core-to-skin and skin-to-air gradients differed between regions under both conditions (P < 0.001). Strong correlations were observed between Tr and Ts (r = 0.88, 0.89, and 0.92 for Tsb, Tse, and Tsf, respectively), suggesting Ts as a strong predictor of Tr. In conclusion, rectal temperatures in finishing broilers are more variable under HS than under TN. Under HS, some birds continue to exhibit Tr in the physiological range. Under TN, heat is transferred from the core to the eyes at a significantly higher rate than to the face and breast skin. However, the breast skin dissipates heat into the environment at a greater rate than the face and the eyes. These patterns of heat transfer between the core and the skin, and between the skin and the environment are conserved under HS. However, heat transfer rates are significantly reduced leading to increased heat load of the birds. These findings provide further insights into thermoregulation in broiler chickens.

Sustainable Poultry Nutrition Using Citric Acid By-Products from Rice to Boost Growth and Carcass Yield in Thai KKU 1 Broiler Chickens

This research aimed to enhance the diet of Thai broiler chickens (KKU 1) by assessing the impact of CABR on growth performance, carcass yield, and meat composition. A total of 320 one-day-old mixed-sex (1:1) Thai KKU 1 broiler chicks were randomly assigned to five dietary treatments incorporating CABR at levels of 0%, 3%, 6%, 9%, and 12%. The chicks were fed for a period of 56 days, divided into three phases: 1-21, 22-49, and 50-56 days. In the grower phase, birds receiving 3% and 6% CABR displayed the lowest feed conversion ratio (FCR) compared to other groups, while their body weight (BW) and BW gain (BWG) were significantly higher than those of other treatments (p < 0.05). In the finisher phase, performance differences were minimal, except for birds on the 3% CABR diet, which had greater BW than those on 9% or 12% CABR diets. Overall, throughout all phases, the inclusion of 3% CABR resulted in improved BWG and FCR compared to other groups across the study period (p < 0.05). Additionally, the 12% CABR treatment reduced dressing percentage compared to other groups, but it did not negatively impact the relative organ weights of the carcass or the quality of breast meat. Incorporating 3% and 12% CABR resulted in the highest values recorded for gross energy and ether extract in breast meat (p < 0.05). Furthermore, the gross energy of thigh meat increased with 3% to 12% CABR inclusion, peaking at the 6% CABR treatment (p < 0.05). This study found that adding 3% or 6% CABR to the diet of Thai broiler chickens improves their growth without negatively impacting meat or carcass quality.

Effects of Black Soldier Fly Larvae Oil on Growth Performance, Blood Biochemical Parameters, Carcass Quality, and Metabolomics Profile of Breast Muscle of Thai Native Chickens

This study aimed to evaluate the effects of the replacement of rice bran oil (RBO) with black soldier fly larvae oil (BSFLO) on growth performance, blood biochemicals, carcass quality, and metabolomics profile of breast muscle of Thai native chickens. A total of 192 1-day-old, mixed-sex, Pradu Hang Dam (Mor Kor 55) chickens were randomly allocated to one of three dietary groups. Each treatment had four replicates with 16 chicks per replicate (8 males and 8 females). Three dietary treatments were used: (T1) the control group, based on a corn-soybean meal with RBO, and two treatment groups that replaced 50% (T2) and 75% (T3) of RBO in the basal diet with BSFLO, respectively. Results showed that BSFLO inclusion at 50% and 75% did not adversely affect the productive performance of Thai native chickens (p > 0.05). Regarding blood profiles, on day 28, chickens fed 75% BSFLO exhibited significant increases in hemoglobin, hematocrit, and MCHC (mean corpuscular hemoglobin concentration) with lower eosinophil percentages compared to the control group (p < 0.05). Additionally, BSFLO supplementation raised glucose levels but decreased globulin and total protein levels (p < 0.05). On day 63, BSFLO inclusion primarily affected MCV (mean corpuscular volume), with higher values in the 50% BSFLO group (p < 0.05). It also increased globulin and HDL (high-density lipoprotein) levels while lowering AST (aspartate transaminase) concentrations (p < 0.05). For carcass and meat quality, BSFLO supplementation did not affect dressing percentage or edible meat yield (p > 0.05). However, it influenced meat pH and shear force (p < 0.05), with a higher pH at 24 h post-mortem in BSFLO-fed chickens. Metabolomics showed that arginine biosynthesis; phenylalanine, tyrosine, and tryptophan metabolism; alanine, aspartate, and glutamate metabolism; arginine and proline metabolism; and taurine and hypotaurine metabolism were the most differentially abundant. These findings suggest that BSFLO can be used for a partial replacement (50 to 75%) for RBO in Thai native chicken diets, potentially offering benefits for animal health and meat quality without compromising growth performance.

The potential of in ovo-fed amino acids to alleviate the effects of heat stress on broiler chickens: effect on performance, body temperature, and oxidative status during the finisher phase

The aim of the current study was to investigate the potential of in ovo-fed amino acids (AA) to reduce the effects of heat stress on finishing broiler chickens. To achieve this, a total of 1,400 fertile hatching eggs were randomly distributed into 5 groups (n = 280/group) and injected with one of the following in ovo treatments on embryonic day 18: 52 µL of sterile diluent/egg (CTRL), CTRL + 1.0 mg of L-Leucine (T1), CTRL + 0.45 mg of leucine + 1.15 mg of methionine (T2), CTRL + 3.0 mg of methionine + 2.0 mg of cysteine (T3), and CTRL + 0.40 mg of leucine + 1.60 mg of methionine + 1.60 mg of cysteine (T4). After hatch, chicks were allocated according to a complete randomized block design comprising 2 thermal conditions: thermoneutral (24°C, 45% RH) and heat stress (34°C, 55-60% RH) with 5 pens/group/condition. The cyclical heat stress regimen (10 h/d) was then applied from d 29 to d 34. Compared to the CTRL group, T3 and T4 exhibited a higher BW during the starter phase (P < 0.001). T4 also had a lower feed conversion ratio (FCR) than CTRL during this same phase (P = 0.03). During the grower phase, males of all treatment groups consistently exhibited higher BW compared to the CTRL group, which was not observed among female birds (PSex × TRT = 0.005). During the finisher phase, the in ovo treatment effect on performance was not significant. However, heat-stressed birds from treatment group T3 and T4 exhibited lower facial temperatures (Pday × TRT < 0.001) as well as lower plasma (Pcondition x TRT = 0.039) and liver (Pcondition x TRT < 0.001) malonaldehyde concentrations compared to the CTRL group. In conclusion, in ovo-fed AA have the potential to modulate the effects of heat stress on finishing broiler chickens by limiting its detrimental consequences, including increased body temperature and oxidative damage.

Thermal impacts on transcriptome of Pectoralis major muscle collected from commercial broilers, Thai native chickens and its crossbreeds

OBJECTIVE

The main objective of this study was to define molecular mechanisms associated with thermal stress responses of chickens from commercial broilers (BR, Ross 308), Thai native chickens (NT) and crossbreeds between BR×NT (H75).

METHODS

Twenty days before reaching specific market age, chickens from each breed were divided into control and thermal-stressed groups. The stressed groups were exposed to a cyclic thermal challenge (35°C±1°C for 6 h, followed by 26°C±1°C for 18 h) for 20 days. Control group was raised under a constant temperature of 26°C±1°C. Pectoralis major (n = 4) from each group was collected for transcriptome analysis using HiSeq Illumina and analysis of glycogen and lactate. Gene expression patterns between control and thermalstressed groups were compared within the same breeds.

RESULTS

Differentially expressed transcripts of 65, 59, and 246 transcripts for BR, NT, and H75, respectively, were revealed by RNA-Seq and recognized by Kyoto encyclopedia of genes and genomes database. Pathway analysis underlined altered glucose homeostasis and protein metabolisms in all breeds. The signals centered around phosphatidylinositol 3-kinase (PI3K)/Akt signaling, focal adhesion, and MAPK signaling in all breeds with slight differences in molecular signal transduction patterns among the breeds. An extensive apoptosis was underlined for BR. Roles of AMPK, MAPK signaling and regulation of actin cytoskeleton in adaptive response were suggested for H75 and NT chickens. Lower glycogen content was observed in the breast muscles of BR and NT (p<0.01) compared to their control counterparts. Only BR muscle exhibited increased lactate (p<0.01) upon exposure to the stress.

CONCLUSION

The results provided a better comprehension regarding the associated biological pathways in response to the cyclic thermal stress in each breed and in chickens with different growth rates.

Effect of fermented dandelion on productive performance, meat quality, immune function, and intestinal microbiota of broiler chickens

BACKGROUND

Dandelion has a great potential to be used as feed additive. Using microbial fermentation technology to degrade cell walls is conducive to enable better release of bioactive compounds of dandelion. This study intended to explore the effect of fermented dandelion (FD) on production performance, meat quality, immune function, and intestinal microbiota of broiler chickens. One-hundred and twenty 1-day-old male Arbor Acres broiler chickens were randomly allotted into three treatments: CON (basal diet, control), LFD and HFD (basal diet with 500 and 1000 mg/kg FD, respectively), with five replicates of eight birds each. The experiment lasted for 42 days.

RESULTS

The results showed that birds in HFD group had increased ADG during 1-21 days (P < 0.05). On day 21, the bursa of Fabricius index of birds in LFD group was higher (P < 0.05), while the serum contents of IFN-γ and TNF-ɑ were lower in HFD group (P < 0.05). FD supplementation decreased the observed_species, shannon, chao1 and ace indexes (P < 0.05) as well as the abundance of Bacteroidota, Bacteroides, and Alistipes (P < 0.05). Birds in HFD group had higher abundance of Firmicutes and lower abundance of Verrucomicrobiota (P < 0.05). LFD group had lower abundance of unidentified_bacteria (P < 0.05). On day 42, the abdominal fat yield of HFD group was decreased (P < 0.05). Birds in LFD group had lower L* and b* values of breast muscle (P < 0.05), while higher spleen index. The CAT activities of breast muscle of FD groups were higher (P < 0.05).

CONCLUSION

In summary, dietary FD supplementation at 1000 mg/kg improved production performance and immune function and modulated microbiota composition in ileum of broiler chickens. FD can be supplemented in the diet to enhance performance and health of broiler chickens, of which 1000 mg/kg FD is more effective.

Effects of Heat Stress on Production Performance, Redox Status, Intestinal Morphology and Barrier-Related Gene Expression, Cecal Microbiome, and Metabolome in Indigenous Broiler Chickens

This study was done to evaluate the effects of heat stress (HS) on production performance, redox status, small intestinal barrier-related parameters, cecal microbiota, and metabolome of indigenous broilers. A total of forty female indigenous broilers (56-day-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 the body weight gain (BWG) of broilers in HS group was lower than those in NT group during 3–4 weeks and 1–4 weeks (p &lt; 0.05). The HS exposure increased the abdominal fat rate (p &lt; 0.05) but decreased the thigh muscle rate (p &lt; 0.01). Besides, broilers in HS group had higher drip loss of breast muscle than NT group (p &lt; 0.01). Broilers exposed to HS had lower total antioxidant capacity (T-AOC) in serum and jejunum, activities of total superoxide dismutase (T-SOD) in the jejunum, glutathione peroxidase (GSH-Px) in the thigh muscle, duodenum, and jejunum; and catalase (CAT) in breast muscle, duodenum, and jejunum (p &lt; 0.05). Whereas the malondialdehyde (MDA) contents in breast muscle, duodenum, and jejunum was elevated by HS exposure (p &lt; 0.05). Moreover, the relative mRNA expression of Occludin and ZO-1 in the duodenum, Occludin, Claudin-1, Claudin-4, ZO-1, Mucin-2 in the jejunum, and the Claudin-4 and Mucin-2 in the ileum was down-regulated by HS exposure (p &lt; 0.05). The 16S rRNA sequencing results showed that the HS group increased the relative abundance of Anaerovorax in the cecum at the genus level (p &lt; 0.05). Cecal metabolomics analysis indicated 19 differential metabolites between the two groups (p &lt; 0.10, VIP &gt;1). The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the differential metabolites mainly enriched in 10 signaling pathways such as the Citrate cycle (TCA cycle) (p &lt; 0.01). In summary, chronic HS exposure caused a decline of production performance, reduced antioxidant capacity, disrupted intestinal barrier function, and negatively affected cecal microbiota and metabolome in indigenous broilers.

Influences of Thermal Stress During Three Weeks Before Market Age on Histology and Expression of Genes Associated With Adipose Infiltration and Inflammation in Commercial Broilers, Native Chickens, and Crossbreeds

The objectives of this study were to examine the effects of cyclic thermal stress on histological characteristics of breast muscle and gene expression regarding adipose infiltration and inflammation in breast muscles collected from different breeds of chickens. The birds, from commercial broilers (CB, Ross 308, 3 weeks), native (NT, 100% Thai native Chee, 9 weeks), H75 (crossbred; 75% broiler and 25% NT, 5 weeks), and H50 (crossbred; 50% broiler and 50% NT, 7 weeks), were equally assigned into control or treatment groups. The control samples were reared under a constant temperature of 26 ± 1°C, while the treatment groups were exposed to 35 ± 1°C (6 h per day). After a 20-day thermal challenge, 12 male birds per treatment group were randomly collected for determination of live body weight, breast weight, numbers of growth-related myopathies, and breast meat chemical composition. Histological lesions were evaluated in the pectoralis major muscle immediately collected within 20 min postmortem based on hematoxylin and eosin staining. The results indicated that despite interaction between thermal stress and breed effects, thermal challenge significantly reduced feed intake, live body weight, and breast weight of the birds and increased moisture content in breast meat (p < 0.05). An interaction between the two main factors was found for protein content (p < 0.05) for which control CB showed less protein than the other groups. Heat stress decreased histological scores for adipose infiltration in CB (p < 0.05), but it did not significantly influence such scores in the other groups. CB received histological scores for adipose tissue at greater extent than those for the other groups. Differential absolute abundance of CD36, FABP4, LITAF, PDGFRA, PLIN1, PPARG, POSTN, SCD1, and TGFB1 in the muscle samples well-agreed with the trend of histological scores, suggesting potential involvement of dysregulated fibro-adipogenic progenitors together with imbalanced lipid storage and utilization in the breast muscle. The findings demonstrated that the cyclic thermal challenge restricted growth performance and breast mass of the birds, but such effects attenuated infiltration of adipose tissue and inflammatory cells in the CB breast muscle.