N-Carbamylglutamate in ovo feeding improves carcass yield, muscle fiber development, and meat quality in broiler chickens.

BACKGROUND: Insufficient endogenous nutrients in the broiler embryo can lead to muscle gluconeogenesis, which ultimately affects the post-hatching performance of chicks. This study investigated the effects of in ovo feeding (IOF) of N-carbamylglutamate (NCG) on the growth hormones, carcass yield, and meat quality in broilers. Fertile eggs from a 30-week-old Ross 308 breeder flock were divided into three treatment groups: NC (non-injection), SC (100 µL saline-injection), and NCG (2 mg NCG injection). Each group had six replicates, with 70 eggs per replicate during incubation. Injections were administered on the 17.5th day of embryonic development. After hatching, 270 chicks were selected for 42-day rearing for further sampling. RESULTS: Chicks in the NCG group had significantly higher body weight (BW) and average daily gain (ADG) at the growing phase, increased growth and testosterone hormone in both feeding phases (21 and 42 days), and improved average daily gain (ADG) and food conversion ratio (FCR) in both grower and entire feeding phases (P < 0.05). Triiodothyronine (T3) and tetraiodothyronine (T4) levels, carcass yield, dressing, drum weight, breast muscle weight, drumstick weights, thighs, pectoralis major, and their part percentage of carcass were improved in the NCG group (P < 0.05), these effects were varied along feeding phases. Moreover, IOF of the NCG also improved pectoralis breast muscle color values at 24 h post mortem (P < 0.05). CONCLUSION: These results suggest that NCG injection at the late embryonic age of broiler enhances growth performance and meat quality throughout the lifespan and this can probably be attributed to an increase in thyroid and testosterone hormones, indicating potential involvement in metabolic and nutrient partitioning pathway regulation. © 2024 Society of Chemical Industry.

Improvement in growth performance and digestive function from amniotic injections of N-acetylglutamate in broiler chickens.

BACKGROUND: N-acetylglutamate (NAG) is the initial and essectial substrate in the process of de novo arginine synthesis, plays an important role in intestinal development. The aim of this study was to determine the effects of in ovo feeding of NAG, 1.5 mg/egg at 17.5 days of incubation (DOI) via amnion, on hatching performance, early intestinal histomorphometry, jejunal barrier, digestive function, and growth performance of broiler chickens between 1 and 14 days of age. RESULTS: Amniotic injection of NAG had no significant effect on hatching characteristics compared with the non-injected control group (NC group). Birds in the NAG solution-injected group (NAG group) exhibited lower average daily feed intake and better feed efficiency during a period of 1-14 days. In comparison with the NC group, the NAG group had decreased crypt depth (CD) in the ileum and increased villus height (VH) / CD in the jejunum at 7 days, and decreased CD in duodenum and significantly increased VH in the jejunum at 14 days. However, the effects of in ovo supplementation with NAG on the density of goblet cells, and gene expression of mucin 2 and alkaline phosphatase were not significant. Chicks in the NAG group had a significantly higher mRNA expression level of trypsin and maltase in jejunum at 7 days than the NC group but not at 14 days. CONCLUSION: Amniotic injections of NAG (1.5 mg/egg) at 17.5 DOI could improve early growth performance of broilers during 1-14 days after hatching by accelerating the development of the intestine and enhancing jejunal digestive function. © 2023 Society of Chemical Industry.

Effects of Pyrroloquinoline Quinone on Lipid Metabolism and Anti-Oxidative Capacity in a High-Fat-Diet Metabolic Dysfunction-Associated Fatty Liver Disease Chick Model.

Metabolic dysfunction-associated fatty liver disease (MAFLD) and its interaction with many metabolic pathways raises global public health concerns. This study aimed to determine the therapeutic effects of Pyrroloquinoline quinone (PQQ, provided by PQQ.Na2) on MAFLD in a chick model and primary chicken hepatocytes with a focus on lipid metabolism, anti-oxidative capacity, and mitochondrial biogenesis. The MAFLD chick model was established on laying hens by feeding them a high-energy low-protein (HELP) diet. Primary hepatocytes isolated from the liver of laying hens were induced for steatosis by free fatty acids (FFA) and for oxidative stress by hydrogen peroxide (H2O2). In the MAFLD chick model, the dietary supplementation of PQQ conspicuously ameliorated the negative effects of the HELP diet on liver biological functions, suppressed the progression of MAFLD mainly through enhanced lipid metabolism and protection of liver from oxidative injury. In the steatosis and oxidative stress cell models, PQQ functions in the improvement of the lipid metabolism and hepatocytes tolerance to fatty degradation and oxidative damage by enhancing mitochondrial biogenesis and then increasing the anti-oxidative activity and anti-apoptosis capacity. At both the cellular and individual levels, PQQ was demonstrated to exert protective effects of hepatocyte and liver from fat accumulation through the improvement of mitochondrial biogenesis and maintenance of redox homeostasis. The key findings of the present study provide an in-depth knowledge on the ameliorative effects of PQQ on the progression of fatty liver and its mechanism of action, thus providing a theoretical basis for the application of PQQ, as an effective nutrient, into the prevention of MAFLD.

Uterine transcriptome analysis reveals mRNA expression changes associated with the ultrastructure differences of eggshell in young and aged laying hens.

BACKGROUND: Lower eggshell quality in the late laying period leads to economic loss. It is a major threat to the quality and safety of egg products. Age-related variations in ultrastructure were thought to induce this deterioration. Eggshell formation is a highly complex process under precise regulation of genes and biological pathways in uterus of laying hens. Herein, we evaluated the physical, mechanical and ultrastructure properties of eggshell and conducted RNA sequencing to learn the transcriptomic differences in uterus between laying hens in the peak (young hens) and late phase (aged hens) of production. RESULTS: The declined breaking strength and fracture toughness of eggshell were observed in aged hen group compared to those in young hen group, accompanied with ultrastructure variations including the increased thickness of mammillary layer and the decreased incidence of early fusion. During the initial stage of eggshell formation, a total of 183 differentially expressed genes (DEGs; 125 upregulated and 58 downregulated) were identified in uterus of laying hens in the late phase in relative to those at peak production. The DEGs annotated to Gene Ontology terms related to antigen processing and presentation were downregulated in aged hens compared to young hens. The contents of proinflammatory cytokine IL-1ß in uterus were higher in aged hens relative to those in young hens. Besides, the genes of some matrix proteins potentially involved in eggshell mineralization, such as ovalbumin, versican and glypican 3, were also differentially expressed between two groups. CONCLUSIONS: Altered gene expression of matrix proteins along with the compromised immune function in uterus of laying hens in the late phase of production may conduce to age-related impairments of eggshell ultrastructure and mechanical properties. The current study enhances our understanding of the age-related deteriorations in eggshell ultrastructure and provides potential targets for improvement of eggshell quality in the late laying period.

Effect of in ovo feeding of ß-hydroxy-ß-methylbutyrate on hatchability, muscle growth and performance in prenatal and posthatch broilers.

BACKGROUND: ß-Hydroxy-ß-methylbutyrate (HMB) is the metabolite of leucine that plays an important role in muscle protein metabolism. The objective of the present study was to determine the effects of in ovo feeding (IOF) of HMB at 7 days of incubation (DOI) via air cell or 18 DOI via amnion on hatchability, muscle growth and performance in prenatal and posthatch broilers. RESULTS: IOF of HMB via air cell at 7 DOI increased hatchability by 4.34% compared with the control (89.67% versus 85.33%). Birds in IOF groups exhibited higher body weight, average daily body weight gain and pectoral muscle percentage. Furthermore, IOF of HMB significantly increased the level of plasma growth hormone, insulin and insulin-like growth factor-1. Chicks hatched from IOF treatment had larger diameters of muscle fiber and higher mitotic activity of satellite cells at early posthatch age. IOF of HMB activated satellite cells by upregulation of mRNA expression of myogenic transcription factors, myogenic differentiation one (MyoD) and myogenin. Chicks hatched from air cell injection group had higher pectoral muscle percentage at 5 d posthatch and greater satellite cell mitotic activity at 7 d posthatch than counterparts from amnion injection group. CONCLUSIONS: IOF of HMB via amnion at 18 DOI or especially via air cell at 7 DOI could be used as an effective approach to enhance hatchability, productive performance and breast muscle yield in broilers. © 2019 Society of Chemical Industry.

Growth performance, carcass characteristics, meat quality and serum profile of broiler chicks fed on housefly maggot meal as a replacement of soybean meal.

A study was conducted to invesstigate the housefly maggot meal (HMM) as an alternative protein source to replace the soybean meal in broiler chick's diet. A total of 720 1-day-old male broiler chicks were divided into three groups and fed diets formulated with HMM to replace soybean meal at the rate of 0%, 4% and 8%. The study lasted for 42 days in two phases. Results showed that HMM addition did not markedly affect body weight, average daily body weight gain and average daily feed intake of the broiler chicks. Feed conversion ratio increased linearly (1-21 days) in starter or quadratically (22-42 days) in the grower phase. HMM non-significantly increased the feed intake and body weight during the grower phase. Slight changes were observed for decrease of blood biochemical indices in the platelets (day 21), and alkaline phosphatase and lysozyme (day 42), and increase for red blood cells, packed cell volume, total protein and uric acid on day 42; however, the fluctuations were within the physiological range. Non-significant effects were observed for carcass composition and meat quality, except that HMM numerically reduced the shear force of breast muscle (linear, p = .058). These results are the strong evidence that HMM can be used as an alternative protein source at 8% in broiler chick's diet without any adverse effect on chick's performance.

Transcriptome analysis reveals mechanism underlying the differential intestinal functionality of laying hens in the late phase and peak phase of production.

BACKGROUND: The compromised performance of laying hens in the late phase of production relative to the peak production was thought to be associated with the impairment of intestinal functionality, which plays essential roles in contributing to their overall health and production performance. In the present study, RNA sequencing was used to investigate differences in the expression profile of intestinal functionality-related genes and associated pathways between laying hens in the late phase and peak phase of production. RESULTS: A total of 104 upregulated genes with 190 downregulated genes were identified in the ileum (the distal small intestine) of laying hens in the late phase of production compared to those at peak production. These upregulated genes were found to be enriched in little KEGG pathway, however, the downregulated genes were enriched in the pathways of PPAR signaling pathway, oxidative phosphorylation and glutathione metabolism. Besides, these downregulated genes were mapped to several GO clusters in relation to lipid metabolism, electron transport of respiratory chain, and oxidation resistance. Similarly, there were lower activities of total superoxide dismutase, glutathione S-transferase and Na+/K+-ATPase, and reductions of total antioxidant capacity and ATP level, along with an elevation in malondialdehyde content in the ileum of laying hens in the late phase of production as compared with those at peak production. CONCLUSIONS: The intestine of laying hens in the late phase of production were predominantly characterized by a disorder of lipid metabolism, concurrent with impairments of energy production and antioxidant property. This study uncovers the mechanism underlying differences between the intestinal functionality of laying hens in the late phase and peak phase of production, thereby providing potential targets for the genetic control or dietary modulation of intestinal hypofunction of laying hens in the late phase of production.

Effect of dietary protein sources on production performance, egg quality, and plasma parameters of laying hens.

OBJECTIVE: This study was conducted to evaluate the effects of dietary protein sources (soybean meal, SBM; low-gossypol cottonseed meal, LCSM; double-zero rapeseed meal, DRM) on laying performance, egg quality, and plasma parameters of laying hens. METHODS: A total of 432 32-wk-old laying hens were randomly divided into 6 treatments with 6 replicates of 12 birds each. The birds were fed diets containing SBM, LCSM100, or DRM100 individually or in combination with an equal amount of crude protein (CP) (LCSM50, DRM50, and LCSM50-DRM50). The experimental diets, which were isocaloric (metabolizable energy, 11.11 MJ/kg) and isonitrogenous (CP, 16.5%), had similar digestible amino acid profile. The feeding trial lasted 12 weeks. RESULTS: The daily egg mass was decreased in the LCSM100 and LCSM50-DRM50 groups (p<0.05) in weeks 41 to 44. The LCSM50 group did not affect egg production compared to the SBM group in weeks 41 to 44 (p>0.05) and showed increased yolk color at the end of the trial (p<0.05). Compared to the SBM group, the LCSM100 and LCSM50-DRM50 groups showed decreased albumen weight (p<0.05), CP weight in the albumen (p<0.05) and CP weight in the whole egg (p<0.05) at 44 weeks. Plasma total protein (TP) levels were lower in the LCSM100 group than in the SBM group at 44 weeks (p<0.05); however, TP, albumin, and globulin levels were not significantly different between the LCSM50 group and the SBM group or between the DRM50 group and the SBM group (p>0.05). CONCLUSION: Together, our results suggest that the LCSM100 or DRM100 diets may produce the adverse effects on laying performance and egg quality after feeding for 8 more weeks. The 100.0 g/kg LCSM diet or the148.7 g/kg DRM diet has no adverse effects on laying performance and egg quality.

Inclusion of guanidinoacetic acid in a low metabolizable energy diet improves broilers growth performance by elevating energy utilization efficiency through modulation serum metabolite profile.

This study was aimed to explore the elevating energy utilization efficiency mechanism for the potentially ameliorative effect of guanidinoacetic acid (GAA) addition on growth performance of broilers fed a low metabolizable energy (LME) diet. A total of 576 d old broilers were randomly allocated to one of the six treatments: a basal diet (normal ME, positive control, PC), or an LME diet (50 kcal/kg reduction in ME, negative control, NC) supplemented with 0.02%, 0.04%, 0.06%, and 0.08% GAA from 1 to 42 d of age, respectively. The GAA fortification in LME diet linearly or quadratically dropped (P < 0.05) the feed conversion ratio (FCR) from 22 to 42 and 1 to 42 d of age, abdominal fat rate on day 42, serum alanine aminotransferase (ALT) on day 21, and serum creatinine (CREAN) on days 21 and 42, elevated (P < 0.05) breast muscle rate and leg muscle rate on day 42, serum creatine kinase (CK) on days 21 and 42, as well as alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) on day 21. The dietary optimal GAA levels were 0.03%-0.08% based on the best-fitted quadratic models (P < 0.03) of the above parameters. Thus, the PC, LME, and 0.04% GAA-LME groups were selected for further analysis. Serum essential amino acids (EAA) tryptophan, histidine and arginine, non-essential amino acids (NEEA) serine, glutamine and aspartic acid were significantly decreased (P < 0.05), compared to PC diet by LME or 0.04% GAA-LME diet. 0.04% GAA-LME group reversed (P < 0.05) the reduction of arginine, 3-methyhistidine, and 1-methylhistidine by LME diet. Besides, six birds at 28 d of age from LME and 0.04% GAA-LME groups were selected for energy utilization observation in calorimetry chambers. The results demonstrated that 0.04% GAA-LME group significantly improved (P < 0.05) the ME intake (MEI) and net energy (NE) compared to the LME diet. Overall, these findings suggest that 0.04% GAA is the ideal dose of broilers fed the LME diet, which can significantly improve the growth performance and carcass characteristics by modulation of creatine metabolism through elevating serum CK activity and arginine concentration.

Guanidinoacetic acid (GAA) has been found to elevate energy utilization efficiency in broilers; however, the underlying mechanisms remain unclear. We investigated the effects of GAA addition in low metabolizable energy (LME) diet on growth performance, carcass characteristics and serum biochemical indices of broilers, and found that GAA addition linearly or quadratically dropped the feed conversion ratio from 22 to 42 and 1 to 42 d of age, abdominal fat rate on day 42, serum alanine aminotransferase on day 21, and serum creatinine on days 21 and 42, elevated breast muscle and leg muscle rate on day 42, serum creatine kinase, alkaline phosphatase, as well as lactate dehydrogenase on days 21 or 22. The dietary optimal GAA levels were 0.03%-0.08% based on the best-fitted quadratic models of the above parameters. Thus, further analysis was conducted and found that 0.04% GAA reversed the reduction of arginine, 3-methyhistidine, and 1-methylhistidine and improved the ME intake and net energy compared to the LME diet. These findings suggested that 0.04% GAA is the ideal dose for enhancing the energy utilization of broilers fed the LME diet, GAA addition can significantly improve the growth performance by elevating energy utilization efficiency through modulation serum metabolite profile.

Decreased eggshell strength caused by impairment of uterine calcium transport coincide with higher bone minerals and quality in aged laying hens.

BACKGROUND: Deteriorations in eggshell and bone quality are major challenges in aged laying hens. This study compared the differences of eggshell quality, bone parameters and their correlations as well as uterine physiological characteristics and the bone remodeling processes of hens laying eggs of different eggshell breaking strength to explore the mechanism of eggshell and bone quality reduction and their interaction. A total of 240 74-week-old Hy-line Brown laying hens were selected and allocated to a high (HBS, 44.83 ± 1.31 N) or low (LBS, 24.43 ± 0.57 N) eggshell breaking strength group. RESULTS: A decreased thickness, weight and weight ratio of eggshells were observed in the LBS, accompanied with ultrastructural deterioration and total Ca reduction. Bone quality was negatively correlated with eggshell quality, marked with enhanced structures and increased components in the LBS. In the LBS, the mammillary knobs and effective layer grew slowly. At the initiation stage of eggshell calcification, a total of 130 differentially expressed genes (DEGs, 122 upregulated and 8 downregulated) were identified in the uterus of hens in the LBS relative to those in the HBS. These DEGs were relevant to apoptosis due to the cellular Ca overload. Higher values of p62 protein level, caspase-8 activity, Bax protein expression and lower values of Bcl protein expression and Bcl/Bax ratio were seen in the LBS. TUNEL assay and hematoxylin-eosin staining showed a significant increase in TUNEL-positive cells and tissue damages in the uterus of the LBS. Although few DEGs were identified at the growth stage, similar uterine tissue damages were also observed in the LBS. The expressions of runt-related transcription factor 2 and osteocalcin were upregulated in humeri of the LBS. Enlarged diameter and more structural damages of endocortical bones and decreased ash were observed in femurs of the HBS. CONCLUSION: The lower eggshell breaking strength may be attributed to a declined Ca transport due to uterine tissue damages, which could affect eggshell calcification and lead to a weak ultrastructure. Impaired uterine Ca transport may result in reduced femoral bone resorption and increased humeral bone formation to maintain a higher mineral and bone quality in the LBS.

Microencapsulated Lactobacillus plantarum promotes intestinal development through gut colonization of layer chicks.

The effects of Lactobacillus plantarum in microencapsulation (LPM) on intestinal development in layer chicks were investigated in this study, as well as the colonization of L. plantarum in the gut. A total of 480 healthy Hy-Line Brown layer chicks at 0 d old were randomly divided into 4 groups (8 replicates each treatment), and the diets of these birds were supplemented with nothing (control), L. plantarum (0.02 g/kg feed; 109 CFU/kg feed), LPM (1.0 g/kg feed; 109 CFU/kg feed) and wall material of LPM (WM; 0.98 g/kg feed), respectively. Compared to control, LPM improved growth performance and intestinal development of layer chicks, evidenced by significantly increased body weight, average daily gain, average daily feed intake, villus height, villus height/crypt depth, as well as weight and length of the duodenum, jejunum and ileum (P < 0.05). These results could be attributed to the increased colonization of L. plantarum in the gut, which was verified by significant increases in lactic acid content, viable counts in chyme and mucosa (P < 0.05), as well as a visible rise in number of strains labeled with fluorescein isothiocyanate. Meanwhile, the relative abundances of Lactobacillus and Bifidobacterium significantly increased in response to microencapsulated L. plantarum supplementation (P < 0.05), accompanied by the significant up-regulation of colonization related genes (P < 0.05), encoding solute carrier family, monocarboxylate transporter, activin A receptor, succinate receptor and secretogranin II. To sum up, microencapsulated L. plantarum supplementation promoted intestinal development, which could be attributed to the enhancement of L. plantarum colonization in the intestine through the mutual assistance of Bifidobacterium and interactions with colonization related transmembrane proteins.

Uterine microbial communities and their potential role in the regulation of epithelium cell cycle and apoptosis in aged hens.

BACKGROUND: Alterations of the uterine microbiome are closely associated with various intrauterine diseases and physiological conditions, which are well-established in mammals. However, as representative oviparous animals, the research on the uterine microbial ecosystem and its functions with physiological homeostasis is limited in chickens. Additionally, continuous egg-laying disrupts the oviducal immune defenses of aged hens, susceptible to pathogen invasion, causing poor egg quality and food-borne infections in humans. Here, we investigated aging-related changes in the oviduct microbial colonization and transmission from the gut to eggs and their roles in a hen model. RESULTS: The results of 16S rDNA sequencing showed significant differences in the oviduct microbial composition between young (38 weeks) and aged (77 weeks) laying hens. SourceTracker analysis further revealed differences in the effects of microbial transmission on the oviducal microbiota between young and aged hens. Enhanced barrier defense with cell apoptosis suppression and cell cycle arrest of the uterus were observed in aged hens reducing microbial transmission from the lower to upper reproductive tract. In addition, a total of 361 significantly differential metabolites were identified using metabolomics in the aged uterine microbiota, especially in products of amino acid metabolism and biosynthesis of various secondary metabolites, which might have essential effects on cell apoptosis by regulating immune responses and cell cycle. Notably, antibiotics disrupted uterine microbiota by dietary intervention and direct perfusion did not retard aging-related physiological changes but further aggravated aging processes by disrupting the cell cycle and apoptosis. CONCLUSIONS: The microbiota continuum along the reproductive tract in aged birds differs from that in young birds, especially with a significant shift in the uterus. The aged uterine microbiota probably contributes to the regulation of cell cycle and apoptosis by microbial metabolites primarily involved in amino acid metabolism and biosynthesis of various secondary metabolites. These findings provide new insights into the roles of the reproductive tract microbiota in regulating the cell programming of the aged host, contributing to the exploration of the microbiome as a target for diagnosing aging health status and therapy for gynecological diseases in women. Video Abstract.

Yeast cell-wall polysaccharides improve immunity and attenuate inflammatory response via modulating gut microbiota in LPS-challenged laying hens.

Effects of dietary supplementation of yeast cell-wall polysaccharides (YCWP) on production performance, ileal microbial composition, immunomodulatory and anti-inflammatory effects in LPS-challenged laying hens, were evaluated. A total of 288 35-week-old Hy-Line Brown layers were randomly assigned into 4 dietary treatments: 0, 250, 500 and 1000 mg/kg YCWP, respectively. After a 12-week feeding period, a total of 32 birds were selected from the control (n = 16) and 1000 mg/kg YCWP group (n = 16). For each group, half (n = 8) received Escherichia coli LPS and half (n = 8) received PBS at 1 mg/kg body weight, intravenously. Results showed that YCWP enhanced feed efficiency and egg production linearly, with optimal laying performance notable in the 1000 mg/kg YCWP group. Dietary YCWP enhanced serum IgM and expression of ileal avian ß-defensin, alleviated the LPS-induced elevated levels of serum IL-6 and IL-1ß and the up-regulated expression of IL-1ß, TNF-α, IFN-γ, and IL-6 in spleen and/or ileal mucosa. Furthermore, anti-inflammatory and immunomodulatory effects of YCWP were linked with its enhancement effect on microbial diversity, proliferation of Bifidobacteriaceae, Lactocillus, Candidatus_Arthromitus, Streptomyces, Bacillaceae, and Desulfovibrio, and reduced abundance of Shigella. Therefore, YCWP has the potentials to be utilized as safe prebiotics and gut enhancer in laying hens.

Glycosylated proteins with abnormal glycosylation changes are potential biomarkers for early diagnosis of breast cancer.

Conventional cancer management relies on tumor type and stage for diagnosis and treatment, which leads to recurrence and metastasis and death in young women. Early detection of proteins in the serum aids diagnosis, progression, and clinical outcomes, possibly improving survival rate of breast cancer patients. In this review, we provided an insight into the influence of aberrant glycosylation on breast cancer development and progression. Examined literatures revealed that mechanisms underlying glycosylation moieties alteration could enhance early detection, monitoring, and therapeutic efficacy in breast cancer patients. This would serve as a guide for the development of new serum biomarkers with higher sensitivity and specificity, providing possible serological biomarkers for breast cancer diagnosis, progression, and treatment.

Recent Trends on Mitigative Effect of Probiotics on Oxidative-Stress-Induced Gut Dysfunction in Broilers under Necrotic Enteritis Challenge: A Review.

Gut health includes normal intestinal physiology, complete intestinal epithelial barrier, efficient immune response, sustained inflammatory balance, healthy microbiota, high nutrient absorption efficiency, nutrient metabolism, and energy balance. One of the diseases that causes severe economic losses to farmers is necrotic enteritis, which occurs primarily in the gut and is associated with high mortality rate. Necrotic enteritis (NE) primarily damages the intestinal mucosa, thereby inducing intestinal inflammation and high immune response which diverts nutrients and energy needed for growth to response mediated effects. In the era of antibiotic ban, dietary interventions like microbial therapy (probiotics) to reduce inflammation, paracellular permeability, and promote gut homeostasis may be the best way to reduce broiler production losses. The current review highlights the severity effects of NE; intestinal inflammation, gut lesions, alteration of gut microbiota balance, cell apoptosis, reduced growth performance, and death. These negative effects are consequences of; disrupted intestinal barrier function and villi development, altered expression of tight junction proteins and protein structure, increased translocation of endotoxins and excessive stimulation of proinflammatory cytokines. We further explored the mechanisms by which probiotics mitigate NE challenge and restore the gut integrity of birds under disease stress; synthesis of metabolites and bacteriocins, competitive exclusion of pathogens, upregulation of tight junction proteins and adhesion molecules, increased secretion of intestinal secretory immunoglobulins and enzymes, reduction in pro-inflammatory cytokines and immune response and the increased production of anti-inflammatory cytokines and immune boost via the modulation of the TLR/NF-ĸ pathway. Furthermore, increased beneficial microbes in the gut microbiome improve nutrient utilization, host immunity, and energy metabolism. Probiotics along with biosecurity measures could mitigate the adverse effects of NE in broiler production.

Comparison of amino acid digestibility of soybean meal, cottonseed meal, and low-gossypol cottonseed meal between broilers and laying hens.

OBJECTIVE: This study aimed to determine and compare the apparent ileal digestibility (AID) and the standardized ileal digestibility (SID) of amino acids (AA) in soybean meal (SBM), cottonseed meal (CSM), and low-gossypol cottonseed meal (LCSM) fed to broiler chickens and laying hens. METHODS: Three semi-purified diets containing the identical crude protein concentration at 20% were formulated to contain SBM, CSM, or LCSM as the sole source of N. A N-free diet was also formulated to estimate the basal ileal endogenous losses of AA for broilers and hens. A total of 300 male Ross 308 chicks at one-day-old and 144 Hy-Line Brown laying hens at 30-week-old with initial egg production rate of 88.3%±1.0% were randomly allocated into 1 of 4 dietary treatments, respectively. RESULTS: CSM and LCSM showed more Arg and Cys+Met while less Lys, Ile, Leu, and Thr relative to SBM. Significant interactions existed between species and experimental diets for AID (except for Arg, Asp, Glu, Gly, and Pro) and SID (except for Arg, His, and Phe) of most AA. Most AA in diets showed higher AID (except for Lys) and SID (except for Lys, Met, and Ser) in broilers relative to laying hens. The AID and SID of all AA were significantly different between the three diets. In broilers, the AID and SID of most indispensable AA except for Arg in SBM and LCSM was higher than CSM. In laying hens, the AID and SID of most indispensable AA except for Arg, Met+Cys, and Phe in SBM was higher than CSM and LCSM. CONCLUSION: The accurate determination of AID and SID of AA in CSM and LCSM for broilers and layers benefits the application of CSM and LCSM in chicken diets. The cottonseed by-products CSM or LCSM showed the species-specific AA digestibility values for broilers and layers.

Effects of Saccharomyces cerevisiae hydrolysate on growth performance, immunity function, and intestinal health in broilers.

The current study was performed to explore the effects of dietary supplementation of Saccharomyces cerevisiae hydrolysate (SCH) on growth performance, immune function, and intestinal health in broiler chicken. A total of 300 Ross 308 male broilers (1-day-old) were randomly assigned to 2 dietary treatments including a basal diet (control group), and a basal diet supplemented with SCH feed additive (500 mg/kg in starter and grower phase, and 250 mg/kg in finisher phase). Each treatment had 6 replicates with 25 birds each. The results showed that the addition of SCH promoted growth during d 15 to 28 (P < 0.05). Although the addition of SCH had no significant effect on the intestinal relative indexes, it significantly increased the jejunum villus height (VH) and the ratio of villus height to crypt depth (VCR) of jejunum, and decreased the crypt depth (CD) of ileum (P < 0.05). Furthermore, SCH addition significantly downregulated the mRNA expression of immunomodulatory genes (TNF-α, IL-1ß, and IL-6), and upregulated the tight junction genes (ZO-1 and Claudin-1) (P < 0.05). High throughput sequencing analysis of bacterial 16S rRNA revealed that dietary SCH supplementation altered cecum microbiota. Alpha diversity analysis showed that a higher bacterial richness in cecum of broilers fed with SCH. The composition of cecum microbiota regulated by SCH addition was characterized by an increased abundance of Firmicutes and a reduced abundance of Bacteroidetes. At the genus level, dietary SCH resulted in a decrease of Bacteroides and an increase of short-chain fatty acids (SCFA) -producing bacteria including Lactobacillus and Faecalibacterium. Taken together, dietary SCH supplementation can stimulate the growth of broilers by regulating the intestinal immunity and barrier function, and improving the intestinal morphology, which may be related to the enhancement of bacterial diversity and the changes of intestinal microbial composition.

Effects of dietary Clostridium butyricum and fructooligosaccharides, alone or in combination, on performance, egg quality, amino acid digestibility, jejunal morphology, immune function, and antioxidant capacity of laying hens.

The present study was conducted to evaluate the effects of Clostridium butyricum (CB) and fructooligosaccharide (FOS) singly or combined, on performance, egg quality, amino acid digestibility, jejunal morphology, immune function and antioxidant capacity in peak-phase laying hens. A total of 288 Hy-Line Brown laying hens (30 weeks of age) were randomly assigned to 4 dietary groups that included basal diet, basal diet +0.02% of CB (zlc-17: 1 × 109 CFU/g) (PRO), basal diet +0.6% FOS (PRE), and basal diet +0.02% CB + 0.6% FOS (SYN) for 12 weeks. Each treatment had 6 replicates with 12 birds each. The results demonstrated that probiotics (PRO), prebiotics (PRE) and synbiotics (SYN) (p ≤ 0.05), respectively, exerted a positive effect on the performance and physiological response of the birds. There were significant increases in egg production rate, egg weight, egg mass, daily feed intake and reduced number of damaged eggs. and zero mortality rate due to dietary PRO, PRE and SYN (p ≤ 0.05) respectively. Also, feed conversion was improved by PRO (p ≤ 0.05). In addition, egg quality assessment showed that; eggshell quality was increased by PRO (p ≤ 0.05) and albumen indices (Haugh unit, thick albumen content, and albumen height) were enhanced by PRO, PRE and SYN (p ≤ 0.05). Further analysis showed that PRO, PRE and SYN (p ≤ 0.05), reduced heterophil to lymphocyte ratio, increased antioxidant enzymes and immunoglobulin concentration. Although spleen index was higher for PRO (p ≤ 0.05) group. The significant increase in villi height, villi width, villi height to crypt depth ratio and reduced crypt depth were obvious for PRO, PRE, and SYN (p ≤ 0.05). Furthermore, improved nutrient absorption and retention evidenced by increased digestibility of crude protein and amino acids, were notable for PRO, PRE, and SYN (p ≤ 0.05) group. Collectively, our findings revealed that dietary CB and FOS alone, or combined, enhanced productive performance, egg quality, amino acid digestibility, jejunal morphology, and physiological response in peak-phase laying hens. Our results would provide direction on nutritional strategies for gut enhancers and better physiological response of peak laying hens.

Uterine inflammation status modulates eggshell mineralization via calcium transport and matrix protein synthesis in laying hens.

This study explored the effects of uterine inflammation on eggshell mineralization, ultrastructure and mechanical properties in laying hens modified by a lipopolysaccharide (LPS) challenge or dietary essential oil (EO) addition. In trial 1, a total of 72 Hy-line Brown layers at 36 wk of age were randomly assigned to 3 treatment groups (n = 8), where they were intravenously injected with phosphate buffered saline, LPS at 1 mg/kg body weight, or LPS 3 times at 24-h intervals. In trial 2, a total of 288 Hy-line Brown layers at 60 wk of age were randomly divided into 4 groups (n = 8), where they were fed basal diets supplemented with EO at 0, 50, 100 and 200 mg/kg for 12 wk. A uterine inflammation model was constructed with LPS treatment, indicated by the elevated expression of IL-1ß and TNF-α (P < 0.05) and lymphocyte infiltration. Uterine inflammation caused remarkable decreases in eggshell thickness and mechanical properties with structure deteriorations (P < 0.05). Uterine inflammation stimulated the expression of matrix proteins ovotransferrin (TF) and ovalbumin (OVAL), while depressing the mRNA levels of calbindin-1 (CALB1) and osteopontin in uterine mucosa (P < 0.05). In contrast, EO addition alleviated uterine inflammation, evidenced by depressed levels of IL-1ß and IL-6 (P < 0.05). There was a significant elevation in shell thickness and breaking strength following EO intervention (P < 0.05), and these effects were maximized at addition of 100 mg/kg. Further, EO improved shell ultrastructure including more early fusion, less type B mammillae, and increased effective thickness (P < 0.05). The alleviated inflammation decreased the expression of OVAL and TF, whereas ion transport genes like CALB1 and solute carrier family 26 member 9 were upregulated (P < 0.05). Our findings suggest that inflammatory status can impact uterine functions in calcium transport and the synthesis of matrix proteins especially such as OVAL and TF, which in turn modulates calcium precipitation and ultrastructure formation, thereby determining eggshell mechanical properties. These findings provide a novel insight into the uterine inflammation-mediated modifications of eggshell quality.

Biophysiology of in ovo administered bioactive substances to improve gastrointestinal tract development, mucosal immunity, and microbiota in broiler chicks.

Early embryonic exogenous feeding of bioactive substances is a topic of interest in poultry production, potentially improving gastrointestinal tract (GIT) development, stimulating immunization, and maximizing the protection capability of newly hatched chicks. However, the biophysiological actions and effects of in ovo administered bioactive substances are inconsistent or not fully understood. Thus, this paper summarizes the functional effects of bioactive substances and their interaction merits to augment GIT development, the immune system, and microbial homeostasis in newly hatched chicks. Prebiotics, probiotics, and synbiotics are potential bioactive substances that have been administered in embryonic eggs. Their biological effects are enhanced by a variety of mechanisms, including the production of antimicrobial peptides and antibiotic responses, regulation of T lymphocyte numbers and immune-related genes in either up- or downregulation fashion, and enhancement of macrophage phagocytic capacity. These actions occur directly through the interaction with immune cell receptors, stimulation of endocytosis, and phagocytosis. The underlying mechanisms of bioactive substance activity are multifaceted, enhancing GIT development, and improving both the innate and adaptive immune systems. Thus summarizing these modes of action of prebiotics, probiotics and synbiotics can result in more informed decisions and also provides baseline for further research.