Effects of Clostridium butyricum on Production Performance and Bone Development of Laying Hens.

Probiotics are safe, inexpensive, and effective feed additives, and Clostridium butyricum (CB) has been reported to regulate bone health in addition to having conventional probiotic effects. The bone health of laying hens is closely related to their production performance. Here, we investigated the effects of CB supplementation on the bone health and performance of laying hens. We added CB to the feed of green-shell laying hens, Luhua laying hens, and Hy-line Brown laying hens and examined changes in body weight, feed intake, egg production performance, and egg quality to determine the impact of CB on production performance. The impact of CB on the bones of laying hens was determined by analyzing the bone index, bone bending strength, bone calcium and phosphorus content, and bone mineral density. The study found that CB had little effect on the body weight and feed intake of laying hens. Feed additions of 108 and 109 CFU/kg CB can significantly increase the tibia index and bone mineral density of four-week-old green-shell laying hens. Feed additions of 107 and 108 CFU/kg CB can significantly increase the average egg weight, eggshell weight, and tibia index of 26-week-old Luhua laying hens, but 107 CFU/kg CB will reduce the egg production rate. Adding 108 CFU/kg CB to feed can significantly increase the average egg weight, eggshell weight, and tibia bending strength of 40-week-old Hy-line Brown laying hens. In summary, adding 108 CFU/kg CB is beneficial to the bone and production health of laying hens.

Beneficial effect of probiotics supplementation on quality of edible fresh table eggs during storage.

Background: This study discussed the effect of probiotic supplementation on laying hens' diets and the enhancement of egg quality during the cold storage period. Aim: To study the efficacy of the addition of probiotics to hen diets in terms of improving the egg's quality during the cold storage period and protection against enteric pathogens. Methods: 100 table eggs were collected from farms of laying hens on a battery system, 46 weeks old HylineW36 white in Sharkia Government. The collected eggs were separated into 2 groups (50 each); the control group from hens fed on diets without probiotics, and the probiotic group from hens fed on diets with (100 g/ton) of supplemented probiotics preparation. All groups were separated into 5 sub-groups for the examinations; on the fresh day, 7th, 14th, 21st, and 28th days on cold storage at 4°C. Chemical, physical, and microbiological examinations were done for internal egg contents and eggshells. Results: Our results showed that probiotics supplements have advantageous effects on the quality of eggs during cold storage periods. Also, microbiological examination proved that eggshells from hens fed on diets with probiotics supplemented (100 g/ton) have decreased the level of bacterial contamination with Salmonella and Escherichia coli than hens fed on a regular diet. Conclusion: It could be shown that the probiotics supplementation may decrease and reduce the effect of the storage period on the quality of shell, albumen, and yolk.

Dietary 25-Hydroxycholecalciferol Supplementation as a Vitamin D3 Substitute Improves Performance, Egg Quality, Blood Indexes, Jejunal Morphology, and Tibia Quality in Late-Phase Laying Hens.

This study aimed to investigate whether a dietary 25-OHD3 addition improved the performance, egg quality, blood indexes, antioxidant status, jejunal morphology, and tibia quality of aged laying hens compared to a dietary VD3 addition. A total of 270 Hy-Line Brown laying hens at 55 wk of age were randomly assigned to three dietary treatments with six replicates (15 birds per replicate with 3 birds per cage). Chickens were fed a corn-soybean meal diet supplementation of 4000 IU/kg VD3 (control group), 50 µg/kg 25-OHD3 and 2000 IU/kg VD3 (experimental group 1), or 50 µg/kg 25-OHD3 and 4000 IU/kg VD3 (experimental group 2) for 12 weeks. The results demonstrated that 25-OHD3 caused a significant increase in the laying rate, especially in the 50 µg/kg 25-OHD3 + 2000 IU/kg VD3 group; the laying rate reached the maximum compared with other groups after 12 weeks (p < 0.05). However, there were no significant effects on the average egg weight, average daily feed intake, or feed-to-egg ratio (p > 0.05). A dietary supplementation of 50 µg/kg 25-OHD3 and 2000 IU/kg VD3 provided an improved eggshell strength, thick albumen height, and Haugh unit after 12 weeks (p < 0.05). Further analysis of the blood indexes showed that alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, calcium, and phosphorus were enhanced significantly in the 50 µg/kg 25-OHD3 + 2000 IU/kg VD3 group, while the content of total bilirubin decreased significantly (p < 0.05). In addition, the 25-OHD3 addition in diets improved the calcium and phosphorus contents in the serum (p < 0.05). The concentrations of 25-OHD3, parathyroid hormones, follicle-stimulating hormone, and progesterone were increased in the 50 µg/kg 25-OHD3 + 2000 IU/kg VD3 group, and the levels of cortisol, calcitonin, bone gla protein, and endotoxin in the serum reached a minimum in the 50 µg/kg 25-OHD3 + 4000 IU/kg VD3 group (p < 0.05), which constitutes an advantage for the aged laying hens. The antioxidant enzyme activities and free radical scavenging abilities in the 50 µg/kg 25-OHD3 + 2000 IU/kg VD3 group increased markedly, and the MDA level decreased significantly in the 50 µg/kg 25-OHD3 + 4000 IU/kg VD3 group (p < 0.05). Improvements in jejunal morphology and intestinal integrity resulted in an increased villi-length-to-crypt-depth ratio in the 50 µg/kg 25-OHD3 + 2000 IU/kg VD3 group (p < 0.05). Dietary 50 µg/kg 25-OHD3 and 2000 IU/kg VD3 additions improved the tibia quality, including fresh tibia weight, strength, mineral content (Ca), and trabeculae area (p < 0.05). Taken together, compared with the dietary VD3 addition, dietary supplementation of 25-OHD3 supported a stable physiological status for sustained egg production, egg quality, and bone quality in late-phase laying hens, and the addition levels of 50 µg/kg 25-OHD3 and 2000 IU/kg VD3 had the best effect. Therefore, this could provide a theoretical basis for the use of 25-OHD3 as a substitute forVD3.

Effects of different supplemental levels of protease DE200 on the production performance, egg quality, and cecum microflora of laying hens.

This study aimed to investigate the effects of different levels of the protease DE200 on the performance, egg quality, organ index, and cecum microflora of Hy-line W36 laying hens. In this experiment, a total of 180 laying hens aged 300 d were randomly divided into three treatment groups and fed diets containing 0, 100, or 200 g/t DE200. The experimental period was 8 wk, including 2 wk of prefeeding and 6 wk of the formal experiment. Regular feeding was performed thrice a day and eggs were collected twice daily, and the feed intake and the egg quality were recorded. The results showed that in terms of production performance, dietary supplementation with different levels of DE200 significantly increased egg production (EP; P < 0.05) and significantly decreased the feed conversion ratio (FCR; P < 0.05) and average daily feed intake (ADFI; P < 0.05) without affecting egg weight (EW). In addition, the addition of DE200 significantly reduced the egg breakage rate (P < 0.05) and tended to increase the Haugh unit and decrease the water content of the yolk (P > 0.05). In the cecal microflora, the addition of DE200 increased the proportions of Bacteroidetes and Firmicutes at the phylum level while reducing the proportion of Fusobacteria. Furthermore, at the genus level, the addition of DE200 increased the proportions of Bacteroides and Faecalibacterium and reduced the proportion of Megamonas. This study suggested that the protease DE200 can be used as a feed supplement to improve the production performance of laying hens.

In the production of laying hens, improving the efficiency of dietary protein utilization is important. The aim of this study was to investigate the effects of the protease DE200 on the performance, egg quality and cecal microflora of Hyline white laying hens. A total of 180 laying hens aged 300 d were randomly divided into three treatment groups and fed diets containing 0, 100, or 200 g/t DE200 for 56 d. The results showed that supplementation with 100 or 200 g/t DE200 in the basal diet improved the production performance and egg quality of laying hens. DE200 (100 g/t) improved the balance of the cecal microflora, and DE200 (200 g/t) increased the richness and diversity of the cecal microflora of laying hens. Dietary supplementation with DE200 can improve the intestinal health and nutrient utilization efficiency of laying hens by improving the intestinal flora.

The impact of dietary oregano essential oil supplementation on fatty acid composition and lipid stability in eggs stored at room temperature.

*1. In many countries, eggs are not refrigerated and must be stored at room temperature. The objective of this study was to explore the effects of dietary oregano oil (275 mg/kg; ORE) versus an unsupplemented control diet (CON) on laying hens on the shelf life and fatty acid profile of eggs.2. Treatments were randomly distributed into 10 pens containing 27 birds each. A total of 200 eggs were collected from both groups on the same day and were stored for either 0, 10, 21 and 35 d. At each storage time, egg yolks were analysed for fatty acid profile and lipid peroxidation.3. The main indicator of lipid peroxidation, malondialdehyde (MDA), was significantly lower in ORE eggs compared to CON eggs (p = 0.001). Storage time had a significant impact on MDA concentrations (p = 0.023), with the highest found after 35 d. Significant differences were found for individual fatty acids, saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA). Palmitic acid, stearic acid, oleic acid, linoleic acid and arachidonic acid were significantly lower in ORE eggs compared to CON eggs (p < 0.05). Palmitoleic acid (p = 0.002), linolenic acid (p = 0.001) and docosahexaenoic acid (DHA, p = 0.001) were significantly higher in ORE eggs.4. Storage only affected oleic, linolenic, linoleic, arachidonic and docosahexaenoic acids (p < 0.05). Total SFA, MUFA, n-6 and ratio of n-3 to n-6 (n-3:n-6) PUFA were significantly higher in CON eggs (p < 0.05). The ratio of SFA to PUFA (SFA:PUFA, p = 0.005) and total n-3 PUFA (p = 0.001) were significantly higher in ORE eggs.5. The n-3:n-6 ratio was significantly impacted by treatment (p = 0.021) and storage (p = 0.031) with no significant interaction. This ratio is important for human health indication and could lead to the development of designer eggs.

Effects of ß-mannanase supplementation on productive performance, inflammation, energy metabolism, and cecum microbiota composition of laying hens fed with reduced-energy diets.

The objective of this study is to investigate the beneficial effects and underlying mechanism of dietary ß-mannanase supplementation on the productive performance of laying hens fed with metabolic energy (ME)-reduced diets. A total of 448 Hy-Line gray laying hens were randomly assigned to seven groups. Each group had 8 replicates with 8 hens. The groups included a control diet (CON) with a ME of 2750 kcal/Kg, diets reduced by 100 kcal/Kg or 200 kcal/Kg ME (ME_100 or ME_200), and diets with 0.15 g/Kg or 0.2 g/Kg ß-mannanase (ME_100+ß-M_0.15, ME_100+ß-M_0.2, ME_200+ß-M_0.15, and ME_200+ß-M_0.2). The productive performance, egg quality, intestinal morphology, inflammatory response, mRNA expression related to the Nuclear factor kappa B (NF-κB) and AMPK pathway, and cecum microbiome were evaluated in this study. ME-reduced diets negatively impacted the productive performance of laying hens. However, supplementation with ß-mannanase improved FCR, decreased ADFI, and restored average egg weight to the level of the CON group. ME-reduced diets increased the levels of interleukin-1ß (IL-1ß) and IL-6 while decreasing the levels of IL-4 and IL-10 in the jejunum of laying hens. However, dietary ß-mannanase supplementation improved jejunum morphology, reduced pro-inflammatory cytokine concentrations, and increased levels of anti-inflammatory factors in laying hens fed with ME-reduced diets. The mRNA levels of IL-6, IFN-γ, TLR4, MyD88, and NF-κB in the jejunum of ME-reduced diets were significantly higher than that in CON, dietary ß-mannanase supplementation decreased these genes expression in laying hens fed with ME-reduced diets. Moreover, dietary ß-mannanase supplementation also decreased the mRNA levels of AMPKα and AMPKγ, and increased the abundance of mTOR in the jejunum of laying hens fed with ME-reduced diets. Cecum microbiota analysis revealed that dietary ß-mannanase increased the abundance of various beneficial bacteria (e.g., g_Pseudoflavonifractor, g_Butyricicoccus, and f_Lactobacillaceae) in laying hens fed with ME-reduced diets. In conclusion, dietary ß-mannanase supplementation could improve the productive performance of laying hens fed with a ME-reduced diet by improving intestinal morphology, alleviating intestinal inflammation, changing energy metabolism-related signaling pathways, and increasing cecum-beneficial microbiota.

Effects of Dietary Supplementation of Essential Oils, Lysozyme, and Vitamins' Blend on Layer Hen Performance, Viral Vaccinal Response, and Egg Quality Characteristics.

Maintaining respiratory tract health is crucial for layers, impacting gut health, laying performance, and egg quality. Viral diseases and standard vaccinations can compromise tracheal epithelium function, leading to oxidative stress. This study assessed the impact of a blend of feed additives, predominantly lysozyme (L), essential oils (EO), and vitamins (VIT) (referred to as L + EO + VIT), on young layers during an oral vaccination schedule. The supplementation significantly enhanced antibody titers for Newcastle Disease Virus (NDV) and Infectious Bronchitis Virus (IBV) after vaccination, trachea functionality and intestinal health in the jejunum, increased egg production, and exhibited a trend toward higher egg weight. Although feed intake showed no significant difference, egg quality remained consistent across experimental groups. Moreover, L + EO + VIT supplementation elevated total phenolic content in eggs, improving oxidative stability in both fresh and stored eggs, particularly under iron-induced oxidation. Notably, it substantially reduced yolk lipid peroxidation and albumen protein carbonyls. In conclusion, water supplementation with L + EO + VIT may enhance humoral immune response to IBV and NDV, positively impacting hen productivity. These findings indicate improved tracheal function and enhanced oxidative stability, emphasizing the potential of this blend in promoting overall health and performance in layers.

Dietary Chinese herbal formula supplementation improves yolk fatty acid profile in aged laying hens.

Chinese herbal formula (CHF) has the potential to improve the performance of aged laying hens through integrated regulation of various physiological functions. The present study aimed to investigate the effects of dietary CHF supplementation on the yolk fatty acid profile in aged laying hens. A total of 144 healthy 307-day-old Xinyang black-feather laying hens were randomly allocated into two groups: a control group (CON, fed a basal diet) and a CHF group (fed a basal diet supplemented with 1% CHF; contained 0.30% Leonurus japonicus Houtt., 0.20% Salvia miltiorrhiza Bge., 0.25% Ligustrum lucidum Ait., and 0.25% Taraxacum mongolicum Hand.-Mazz. for 120 days). The fatty acid concentrations in egg yolks were analyzed using a targeted metabolomics technology at days 60 and 120 of the trial. The results showed that dietary CHF supplementation increased (p < .05) the concentrations of several saturated fatty acids (SFA, including myristic acid and stearic acid), monounsaturated fatty acids (MUFA, including petroselinic acid, elaidic acid, trans-11-eicosenoic acid, and cis-11-eicosenoic acid), polyunsaturated fatty acids (PUFA, including linolelaidic acid, linoleic acid, γ-linolenic acid, α-linolenic acid, 11c,14c-eicosadienoic acid, eicosatrienoic acid, homo-γ-linolenic acid, arachidonic acid, and docosapentaenoic acid), and fatty acid indexes (total MUFA, n-3 and n-6 PUFA, PUFA/SFA, hypocholesterolemic/hypercholesterolaemic ratio, health promotion index, and desirable fatty acids) in egg yolks. Collectively, these findings suggest that dietary CHF supplementation could improve the nutritional value of fatty acids in egg yolks of aged laying hens, which would be beneficial for the production of healthier eggs to meet consumer demands.

Effects of selenium-enriched yeast dietary supplementation on egg quality, gut morphology and caecal microflora of laying hens.

Selenium (Se) is an essential micronutrient for humans and animals and is a powerful antioxidant that can promote reproductive and immune functions. The purpose of this study was to evaluate the effects of supplemental dietary selenium-enriched yeast (SeY) on egg quality, gut morphology and microflora in laying hens. In total, 100 HY-Line Brown laying hens (45-week old) were randomly allocated to two groups with 10 replicates and fed either a basal diet (without Se supplementation) or a basal diet containing 0.2 mg/kg Se in the form of SeY for 8 weeks. The Se supplementation did not have a significant effect on egg quality and intestinal morphology of laying hens. Based on the 16S rRNA sequencing, SeY dietary supplementation effectively modulated the cecal microbiota structure. An alpha diversity analysis demonstrated that birds fed 100 mg/kg SeY had a higher cecal bacterial diversity. SeY dietary addition elevated Erysipelotrichia (class), Lachnospiraceae (family), Erysipelotrichaceae (family) and Ruminococcus_torques_group (genus; p < .05). Analysis of microbial community-level phenotypes revealed that SeY supplementation decreased the microorganism abundance of facultatively anaerobic and potentially pathogenic phenotypes. Overall, SeY supplementation cannot significantly improve intestinal morphology; however, it modulated the composition of cecal microbiota toward a healthier gut.

Effects of enzymolysis and fermentation of Chinese herbal medicines on serum component, egg production, and hormone receptor expression in laying hens.

OBJECTIVE: In the present study, we aimed to investigate the effects of enzymolysis fermentation of Chinese herbal medicines (CHMs) on egg production performance, egg quality, lipid metabolism, serum reproductive hormone levels, and the mRNA expression of the ovarian hormone receptor of laying hens in the late-laying stage. METHODS: A total of 360 Hy-Line Brown laying hens (age, 390 days) were randomly categorized into four groups. Hens in the control (C) group were fed a basic diet devoid of CHMs, the crushed CHM (CT), fermented CHM (FC), and enzymatically fermented CHM (EFT) groups received diets containing 2% crushed CHM, 2% fermented CHM, and 2% enzymatically fermented CHM, respectively. RESULTS: Compared with crushed CHM, the acid detergent fiber, total flavonoids, and total saponins contents of fermented CHM showed improvement (p<0.05); furthermore, the neutral and acid detergent fiber, total flavonoids, and total saponins contents of enzymatically fermented CHM improved (p<0.05). At 5 to 8 weeks, hens in the FC and EFT groups showed increased laying rates, haugh unit, albumin height, yolk color, shell thickness, and shell strength compared with those in the C group (p<0.05). Compared with the FC group, the laying rate, albumin height, and Shell thickness in the EFT group was increased (p<0.05). Compared with the C, CT, and FC groups, the EFT group showed reduced serum total cholesterol and increased serum luteinizing hormone levels and mRNA expressions of follicle stimulating hormone receptor and luteinizing hormone receptor (p<0.05). CONCLUSION: These results indicated that the ETF group improved the laying rate and egg quality and regulated the lipid metabolism in aged hens. The mechanism underlying this effect was likely related to cell wall degradation of CHM and increased serum levels of luteinizing hormone and mRNA expression of the ovarian hormone receptor.

Effects of dietary supplement of ε-polylysine hydrochloride on laying performance, egg quality, serum parameters, organ index, intestinal morphology, gut microbiota and volatile fatty acids in laying hens.

BACKGROUND: ε-polylysine hydrochloride (ε-PLH) is a naturally occurring antimicrobial peptide extensively utilized in the food and medical industries. However, its impact on animal husbandry remains to be further explored. Therefore, the present study aimed to determine the effect of ε-PLH on laying hens' health and laying performance. RESULTS: Dietary supplementation with ε-PLH to the diet significantly increased average egg weight during weeks 1-8. Meanwhile, compared with the control group, supplementation with ε-PLH decreased the feed egg ratio during weeks 9-12 and egg breakage rate during weeks 9-16 ，whereas it increased eggshell strength during weeks 1-4 and 13-16 . The ε-PLH 0.05% group increased yolk percentage during weeks 5-8 and yolk color during weeks 1-4 . Furthermore, ε-PLH supplementation significantly increased the concentrations of total protein, albumin, globulin and reproductive hormones estradiol, as well as decreased interleukin-1 beta and malondialdehyde in the serum. Compared with the control group, supplementation with 0.05% ε-PLH significantly increased the relative abundance of Cyanobacteria and Gastranaerophilales and decreased the abundance of Desulfovibrio and Streptococcus in the cecum microbiota. In addition, ε-PLH 0.1% supplementation also increased acetic acid content in the cecum. CONCLUSION: Dietary supplementation with ε-PLH has a positive impact on both productive performance and egg quality in laying hens. Furthermore, ε-PLH can also relieve inflammation by promoting the immunity and reducing oxidative damage during egg production. ε-PLH has been shown to improve intestinal morphology, gut microbial diversity and intestinal health. © 2023 Society of Chemical Industry.

Using low-protein diet in egg production for win-win of productivity and environmental benefits should be prudent: Evidence from pilot test.

A shortage of feed protein resources restricts poultry productivity. Key strategies to alleviate this problem include improvements to the structure of the gut microbiota by the appropriate intake of high-quality protein, improvements to the comprehensive protein utilization rate, and reducing the consumption of protein raw materials. In addition, damage to the environment caused by nitrogen emissions needs to be reduced. The aim of the study was to evaluate the effects of dietary protein levels on laying performance, host metabolism, ovarian health, nitrogen emissions, and the gut microbial structure and function of laying hens. In total, 360 hens at the age of 38 weeks were randomly allotted four treatments. Each of the groups consisted of nine replicates, with 10 birds per replicate, used for 12 weeks of study. Dietary protein levels of the four groups were 13.85 %, 14.41 %, 15.63 %, and 16.30 %. Results revealed that, compared with the 13.85 % crude protein (CP) group, the 15.63 % CP group experienced significantly enhanced final body weight, average daily gain, egg production, and egg mass. Compared with the 16.30 % CP group, the other groups' serum concentrations of immunoglobulin G (IgG) and immunoglobulin M (IgM) were significantly reduced. Compared with the 16.30 % CP group, the 13.85 % and 15.63 % groups had increased CP utilization rates but reduced nitrogen emission rate, and daily per egg and per kilogram egg nitrogen emissions rose with increased dietary protein levels. Compared to the 13.85 % and 14.41 % CP groups, the 16.30 % CP group exhibited a significant increase in the expression of genes related to amino acids and carbohydrate metabolic pathways. According to the linear discriminant analysis effect size diagram, the predominant bacteria in the 15.63 % CP group (e.g., Subdoligranulum, and Ruminococcaceae_UCG-013) were significantly related to CP utilization. The results of this study emphasize that production performance is significantly reduced when protein levels are too low, whereas too high protein levels lead to gut microbiota imbalance and a reduction in the utilization efficiency of nutrients. Therefore, on the premise of ensuring the health of hens, the structure of the gut microbiota can be improved by appropriately reducing protein levels, which helps to balance the relationships among host health, productivity, resources, and the environment.

Orychophragmus violaceus and/or chicory forage affects performance, egg quality, sensory evaluation and antioxidative properties in native laying hens.

Orychophragmus violaceus (OV) and chicory (Cichorium intybus L., CC) can be used as fresh or dry forage for animals. To determine whether OV and/or CC have beneficial effects on performance and egg quality, a total of 1212 28-wk-old Beijing You Chicken (BYC) laying hens with similar performance were randomly allocated to 4 groups with 3 replicate pens per group, and 101 birds per pen. The birds were fed a basal diet (control), the basal diet + OV (3.507 kg/d/pen), the basal diet + CC (2.525 kg/d/pen), and the basal diet + OV + CC (OVC, 1.7535 kg/d/pen OV + 1.2625 kg/d/pen CC) for 3 wks after one wk of adaptation. The results showed that egg-laying rate was not affected by OV, CC and OVC (p > 0.05), but weekly average egg mass was significantly increased by OV and CC (p < 0.05). The feed egg ratio in the CC group (2.82) was significantly lower than that in the other three groups (p < 0.05). The eggshell thickness (EST), albumen height (AH) and Haugh unit (HU) were decreased by OV and CC (p < 0.05); while yolk color (YC) was increased in the CC and OVC groups (p < 0.05). Egg grade was decreased by OV (p < 0.05). Sensory evaluation showed that there was a trend for increased YC in OV, CC and OVC (p = 0.089). Serum total protein was significantly lower in OV group than those in the control and CC group (p < 0.05); serum albumin content was significantly decreased in OV, CC and OVC groups (p = 0.006). Serum glutathione peroxidase activity in CC and OVC groups was significantly higher than that in the control group (p < 0.05). In conclusion, the present study suggests that CC had a better effect on the performance of the native laying hens than OV. The OV and CC affected egg quality, while YC was increased in CC and OVC groups. The OVC improved YC and serum antioxidative properties of native laying hens without affecting the performance.

Graded levels of Eimeria infection modulated gut physiology and temporarily ceased the egg production of laying hens at peak production.

An experiment was conducted to investigate the changes in gastrointestinal physiology, including intestinal leakage, immune response, oxidative stress, along with performance traits, of Hy-Line W-36 laying hens following Eimeria infection at peak egg production. A total of 360 laying hens, at 25 wk of age, were assigned randomly to 5 treatment groups, each consisting of 6 replicate cages, including a nonchallenged control group. The other 4 groups were inoculated with graded levels of mixed Eimeria species as high, medium-high, medium-low, and low doses, respectively. The body weight (BW) and body weight gain (BWG) of laying hens were measured from 0 to 14 days postinoculation (DPI). Average daily feed intake (ADFI) and hen-day egg production (HDEP) were measured from 0 to 15 and 0 to 28 DPI, respectively. Gut permeability was measured on 5 DPI, whereas oxidative stress, immune response, and expression of nutrient transporter genes were measured on 6 and 14 DPI. A significant linear reduction in BW and BWG was observed with increased Eimeria inoculation dosage on both 6 and 14 DPI (P < 0.001, P-Lin < 0.0001). An interaction between the Eimeria dosages and DPI was observed for ADFI (P < 0.0001). Feed intake in the challenged groups decreased starting at 4 DPI, with the most significant drop occurring at 7 DPI, which did not recover until 15 DPI. Following the challenge, gastrointestinal physiology shifted toward the host defense against the Eimeria infection by upregulating mRNA expression of tight junction proteins and immune responses while downregulating the expression of key nutrient transporters on 6 and 14 DPI (P < 0.05). An interaction between the Eimeria inoculation dosage and DPI was also observed for daily HDEP (P < 0.0001). Overall, HDEP was lower in the challenged groups compared to the control. Daily HDEP in the challenged groups dropped from 8 DPI and became similar to the control birds only after 24 DPI. Egg production temporarily ceased in most of the laying hens infected with the high and medium-high dosages of Eimeria. In conclusion, Eimeria infection activated the host immune response, negatively affecting the gastrointestinal health, growth performance, and temporarily ceased the egg production of Hy-Line W-36 laying hens when infected at peak production.

Effects of dietary supplementation with tea polyphenols and probiotics on laying performance, biochemical parameters intestinal morphology and microflora of laying hens.

This study was conducted to investigate the effects of tea polyphenols (TP) and probiotics (PB) on the production performance, biochemical indices, and gut health of laying hens. A total of 400 Hy-line Brown layers (45 weeks old) were randomly assigned to 8 diet groups for 8-week feeding trial. Compared with the control basal diet (CT), dietary high dosage of TP and PB (HTP-PB) increased egg mass (P < 0.05). Supplementation with HTP-PB improved the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and decreased the malonic dialdehyde (MDA) content (P < 0.05) without affecting the contents of immunoglobulins in the serum. The combination of HTP and PB supplementation promoted the secretion of estradiol (E2) and progesterone (PROG) compared with treatment with TP or PB alone (P < 0.05). The combined use of HTP and PB induced higher jejunal villus height (VH) than the CT group (P < 0.05). Dietary TP and PB could optimize the functional network of intestinal microflora and the interactions between the intestinal microflora and the host. Therefore, the combined use of the high dosage of TP and PB affected laying performance, improved antioxidant capacity, and promoted intestinal health, which may be associated with regulation of the intestinal microbiota.

Improving gut functions and egg nutrition with stevia residue in laying hens.

This study aimed to investigate the effect of stevia residue (STER) on the production performance, egg quality and nutrition, antioxidant ability, immune responses, gut morphology and microbiota of laying hens during the peak laying period. A total of 270 Yikoujingfen NO. 8 laying hens (35 wk of age) were randomly divided into 5 treatments. The control group fed a basal diet and groups supplemented with 2, 4, 6, and 8% STER. The results showed that STER significantly increased egg production, the content of amino acids (alanine, proline, valine, ornithine, asparagine, aspartic acid, and cysteine) in egg whites, and decreased the yolk color (P < 0.05). Additionally, STER significantly increased acetate, HOMOγ linolenic acid and cis-13, 16-docosadienoic acid levels in egg yolk (P < 0.05). IL-2, IL-4, and IL-10 levels in serum significantly increased by STER (P < 0.05), while IL-1ß significantly decreased (P < 0.05). STER also increased total antioxidant activity (T-AOC) in the liver and estradiol level in the oviduct (P < 0.05), but decreased the cortisol level in the oviduct (P < 0.05). For the intestinal morphology, the jejunal villus height and crypt-to-villus (V:C) significantly increased by STER (P < 0.05). STER increased the relative abundance of Actinobacteriota (P < 0.05), while deceased Proteobacteria, Desulfobacterota, and Synergistota (P < 0.05). In conclusion, STER improved egg production, quality and nutrition, improved the immune responses, antioxidant capabilities, estrogen level, gut morphology, and increased the relative abundance of beneficial bacteria while decreased the harmful bacteria. Among all treatments, 4 and 6% STER supplementation yielded the most favorable results in terms of enhancing production performance, egg nutrition, gut health, and immune capabilities in laying hens.

Dietary Eucommia ulmoides leaf extract improves laying performance by altering serum metabolic profiles and gut bacteria in aged laying hens.

The leaves of Eucommia ulmoides are rich in bioactive constituents that have potential gastrointestinal benefits for animals. In aged laying hens, intestinal health issues contribute to a significant decline in egg-laying capacity during intermediate and later stages. It remains unclear whether E. ulmoides leaf extract (ELE) can improve intestinal health and enhance egg production in elderly laying hens, and the underlying mechanisms are yet to be elucidated. Therefore, we conducted a study with 480 laying hens (65 weeks old) randomly allocated into four groups: a control group fed with the basal diet, and three treatment groups supplemented with 500, 1,000, and 2,000 mg/kg of ELE, respectively. The primary active constituents of ELE include flavonoids, polysaccharides, terpenoids, and phenolic acids. Dietary supplementation with ELE at 1,000 mg/kg (ELE1000) significantly improved laying performance and egg quality compared to the other groups. ELE1000 stimulated the maturation of intestinal epithelial cells, increased villus height, and reduced crypt depth. It also influenced the levels of proteins associated with tight junctions (claudin-1 and claudin-2) and intestinal inflammatory factors (IL-6, IL-1ß, and IL-2) in different intestinal sections. Integrative analysis of serum metabolomics and gut microbiota revealed that ELE1000 improved nutrient metabolism by modulating amino acid and ubiquinone biosynthesis and influenced the abundance of intestinal microbiota by enriching pivotal genera such as Bacteroides and Rikenellaceae_RC9_gut_group. We identified 15 metabolites significantly correlated with both gut microbiota and laying performance, e.g., DL-methionine sulfoxide, THJ2201 N-valerate metabolite, tetracarbonic acid, etc. In conclusion, ELE1000 improved laying performance in elderly laying hens by affecting intestinal morphology, barrier function, microbiota, and serum metabolite profiles. These findings suggest that ELE can be a beneficial feed additive for extending the peak producing period in aged laying hens.

Effect of Lactic Acid and pH of Probiotic Yogurt on Peak Production of Laying Hens.

<b>Background and Objective:</b> Probiotic yogurt is beneficial for laying hens because it can improve the animal's hematological status which will improve livestock health, therefore it is hoped that probiotic yogurt can increase the production of laying hens. This research was conducted to determine the lactic acid levels and pH of probiotic yogurt, probiotic yogurt's effect on feed conversion ratio and total production of laying hens. <b>Materials and Methods:</b> The research was carried out using experimental methods using a Completely Randomized Design (CRD) with 5 treatments and 8 replications so the total sample was 40. The treatment consisted of P0: Basal ration; P1: Basal diet+2% probiotic powder B1 (<i>Bifidobacterium</i> spp. and <i>L. acidophilus</i>), P2: Basal ration+3% probiotic powder B1, P3: Basal diet+2% probiotic powder B2 (<i>L. bulgaricus</i>, <i>S. thermophilus</i>, <i>L. acidophilus</i> and <i>B. bifidum</i>) and P4: Basal ration+3% probiotic powder B2. The data were analyzed using Analysis of Variance (ANOVA) and followed by Duncan's Multiple Range Test. <b>Results:</b> Lactic acid content in probiotic yogurts B1 is 0.945% and B2 is 0.638%. Based on the results of statistical analysis using the variance test, show that giving probiotic powder to laying hens has a significant effect on the feed conversion ratio and has no significant effect on the production of laying hens. <b>Conclusion:</b> Based on the results of statistical analysis using the variance test, it shows that giving probiotic powder to laying hens has no significant effect on the production of laying hens during the peak period.

Transcriptome analysis of hypothalamus and pituitary tissues reveals genetic mechanisms associated with high egg production rates in Changshun green-shell laying hens.

BACKGROUND: Changshun green-shell laying hens are unique to the Guizhou Province, China, and have high egg quality but relatively low yield. Egg production traits are regulated by the hypothalamus-pituitary-ovary axis. However, the underlying mechanism remains unclear. Thus, we conducted RNA sequencing of hypothalamic and pituitary tissues from low- and high-yielding Changshun green-shell laying hens to identify critical pathways and candidate genes involved in controlling the egg production rate. RESULTS: More than 39 million clean reads per sample were obtained, and more than 82% were mapped to the Gallus gallus genome. Further analysis identified 1,817 and 1,171 differentially expressed genes (DEGs) in the hypothalamus and pituitary, respectively. Nineteen DEGs were upregulated in both the hypothalamus and pituitary of high-yielding chickens. The functions of these DEGs were mainly associated with ion transport or signal transduction. Gene set enrichment analysis revealed that the pathways enriched in the hypothalamus were mainly associated with gonadotropin-releasing hormone (GnRH) secretion, neurotransmitter release, and circadian rhythms. The pathways enriched in the pituitary were mainly associated with GnRH secretion, energy metabolism, and signal transduction. Five and four DEGs in the hypothalamus and pituitary, respectively, were selected randomly for qRT-PCR analysis. The expression trends determined via qRT-PCR were consistent with the RNA-seq results. CONCLUSIONS: The current study identified 19 DEGs upregulated in both the hypothalamus and pituitary gland, which could provide an important reference for further studies on the molecular mechanisms underlying egg production in Changshun green-shell laying hens. In addition, enrichment analysis showed that GnRH secretion and signal transduction, especially neurotransmitter release, play crucial roles in the regulation of egg production.

Feeding laying hens with lactobacilli improves internal egg quality and animal health.

Feeding animals with lactobacilli strains is a biotechnological strategy to improve production, food quality, and animal health. Thus, this study aimed to select new lactic acid bacteria (LAB) able to improve laying hens health and egg production. Forty Bovans White layers (two days old) were randomly divided into four experimental groups that receive an oral gavage with saline solution (control group) or with one of the three lactobacilli selected (KEG3, TBB10, and KMG127) by their antagonistic activity against the foodborne pathogen Bacillus cereus GGD_EGG01. 16 S rRNA sequencing identified KEG3 as Lentilactobacillus sp., and TBB10 and KMG127 as Lactiplantibacillus sp. The data showed that feeding birds with LAB increased weight uniformity and improved the internal quality of the eggs (high yolk index and Haugh unit) compared with the control group (p < 0.05). Beta-diversity analysis showed that LAB supplementation modifies the cecal microbiota of laying hens. The prokaryotic families Bacteroidaceae, Ruminococcaceae, Rikenellaceae, and Lactobacillaceae were most important to the total dissimilarity of the cecal microbial community (calculated by SIMPER test). At end of in vivo experiments, it was possible to conclude that the feed of laying hens with Lentilactobacillus sp. TBB10 and Lentilactobacillus sp. KEG3 can be an important biotechnological tool for improving food quality and animal health.