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 physiol...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 physiologi-cal 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 24074-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 osteocal-cin 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.展开更多
Background:Dietary essential oil(EO)supplementation can exert favorable effects on gut health in broilers.However,it is unknown whether EO could improve intestinal functions,consequently beneficial for egg performance...Background:Dietary essential oil(EO)supplementation can exert favorable effects on gut health in broilers.However,it is unknown whether EO could improve intestinal functions,consequently beneficial for egg performance and quality in late-phase laying hens.This study was aimed to investigate the potential effects of EO on production performance,egg quality,intestinal health and ileal microbiota of hens in the late phase of production.A total of 28860-week-old Hy-line Brown laying hens were randomly divided into 4 groups and fed a basal diet(control)or basal diets supplemented with oregano EO at 100,200 and 400 mg/kg(EO100,EO200 and EO400).Results:Dietary EO supplementation resulted in a quadratic decrease(P<0.05)in feed conversion ratio with lower(P<0.05)feed conversion ratio in EO200 group than the control during weeks 9–12 and 1–12 of the trial.Compared to the control,EO addition resulted in higher(P<0.05)eggshell thickness at the end of week.4,8 and 12 and higher(P<0.05)chymotrypsin activity.There was a quadratic elevation(P<0.05)in ileal chymotrypsin and lipase activity,along with a linear increase in villus height to crypt depth ratio.Quadratic declines(P<0.05)in mRNA expression of IL-1β,TNF-α,IFN-γ and TLR-4,concurrent with a linear and quadratic increase(P<0.05)in ZO-1 expression were identified in the ileum with EO addition.These favorable effects were maximized at medium dosage(200 mg/kg)of EO addition and intestinal microbial composition in the control and EO200 groups were assessed.Dietary EO addition increased(P<0.05)the abundances of Burkholderiales,Actinobacteria,Bifidobacteriales,Enterococcaceae and Bacillaceae,whereas decreased Shigella abundance in the ileum.Conclusions:Dietary EO addition could enhance digestive enzyme activity,improve gut morphology,epithelial barrier functions and modulate mucosal immune status by altering microbial composition,thus favoring feed efficiency and eggshell quality of late-phase laying hens.展开更多
Background: Meat color and lipid peroxidation are important traits related to meat quality. CO_2 concentration is a critical factor that can affect meat quality in the commercial use of gas stunning(GS). However, the ...Background: Meat color and lipid peroxidation are important traits related to meat quality. CO_2 concentration is a critical factor that can affect meat quality in the commercial use of gas stunning(GS). However, the effect and mechanism of CO_2 stunning on meat color and lipid peroxidation during long-term storage remain poorly studied. We aimed to study the effects of GS methods, especial y CO_2 concentration, on meat color and meat lipid peroxidation in broilers during long-term storage at 4 °C and to explore the potential mechanism of meat color change via lipid peroxidation and the inner lipid peroxide scavenging system.Methods: Eighteen broilers were sacrificed after exposure to one of the following gas mixtures for 90 s: 40% CO_2+21% O_2+ 39% N2(G40%), 79% CO_2+ 21% O_2(G79%), or no stunning(0% CO_2, control). Meat color, serum variables,enzyme activities, and the gene expression of mitogen-activated protein kinase(MAPK), nuclear factor-erythroid2-related factor 2(Nrf2), glutathione S-transferase(GST) and superoxide dismutase(SOD) were determined.(Continued on next page)Results: The concentrations of serum triiodothyronine(T3, P = 0.03) and the ratio of serum free triiodothyronine/free thyroxine(FT3/FT4, P < 0.01) were decreased, whereas levels of serum cortisol(P < 0.01) were increased in the 40%CO_2 group compared with the control group. Additionally, the thiobarbituric acid-reactive substances(TBARS)3 d(P < 0.01) and TBARS6 d(P = 0.01) in breast meat and the TBARS3 din thigh meat(P < 0.01) were increased in the40% CO_2 group compared with the control group. Serum T3 was negatively correlated with TBARS6 dboth in the breast and thigh meat(r =-0.63, P < 0.01 and r =-0.47, P = 0.05 respectively). T3/T4 was negatively correlated with TBARS6 din the breast meat and in the thigh meat(r =-0.57, P = 0.01; and r =-0.53, P = 0.03 respectively). Compared with the control group, Lightness(L*)1 d(P = 0.03) and L*9 d(P < 0.01) were increased, whereas total chromatic aberration(E*)1 d(P = 0.05) and E*3 d(P < 0.01) were decreased in the breast meat of both the G40% and G79% groups. The values of yel owness(b*)3 d(P = 0.01), b*6 d(P < 0.01) and E*6 d(P < 0.01) in the thigh meat were lower in both the G40% and G79% groups than in the control group. In the breast muscle, the m RNA levels of c-Jun N-terminal kinase 2(JNK2, P = 0.03),GSTT1(P = 0.04), and SOD1(P = 0.05) were decreased, and the m RNA levels of JNK1(P = 0.07), Nrf2(P = 0.09), and GSTA3(P = 0.06) were slightly lower in both the G40% and G79% groups compared with the control group. However, among these genes, only the m RNA level of JNK1 was decreased in the G40% group compared with the control group and the G79% group(P = 0.03) in the thigh muscle.Conclusions: Compared with the control group, meat color quality in the breast meat was decreased, and the expression of genes in the MAPK/Nrf2/ARE(antioxidant responsive element) antioxidant pathway in breast muscle was partly suppressed by GS of both 40% and 79% CO_2. However, oxidative stress and meat lipid peroxidation during storage were aggravated by GS with 40% CO_2 compared to GS with 79% CO_2 and no GS.展开更多
Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed a...Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed addi-tives for their ability to improve growth performance and intestinal health in poultry.However,whether dietary OA can ameliorate HSD stress-induced impaired intestinal barrier in broilers remains elusive.In this study,a total of 528 one-day-old male Arbor Acres broilers were randomly allocated into 3 treatments with 12 replicates per treatment including 10 birds for normal stocking density and 17 birds for HSD.The dietary treatments were as follows:1)Normal stocking density+basal diet;2)HSD+basal diets;3)HSD+OA.Results:HSD stress can induce increased levels of serum corticosterone,lipopolysaccharides,interleukin-1β,tumor necrosis factor-α,and down-regulated mRNA expression of ZO-1,resulting in compromised growth performance of broilers(P<0.05).Dietary OA could significantly reduce levels of serum corticosterone,lipopolysaccharides,interleukin-1β,and tumor necrosis factor-α,which were accompanied by up-regulated interleukin-10,mRNA expres-sion of ZO-1,and growth performance(P<0.05).Moreover,OA could down-regulate the mRNA expression of TLR4 and MyD88 to inhibit the NF-κB signaling pathway(P<0.05).Additionally,HSD stress significantly decreased the abundance of Bacteroidetes and disturbed the balance of microbial ecosystems,whereas OA significantly increased the abundance of Bacteroidetes and restored the disordered gut microbiota by reducing competitive and exploita-tive interactions in microbial communities(P<0.05).Meanwhile,OA significantly increased the content of acetic and butyric acids,which showed significant correlations with intestinal inflammation indicators(P<0.05).Conclusions:Dietary OA ameliorated intestinal inflammation and growth performance of broilers through restor-ing the disordered gut microbial compositions and interactions induced by HSD and elevating short-chain fatty acid production to inhibit the TLR4/NF-κB signaling pathway.These findings demonstrated the critical role of intestinal microbiota in mediating the HSD-induced inflammatory responses,contributing to exploring nutritional strategies to alleviate HSD-induced stress in animals.展开更多
This study was aimed to investigate the effects of dietary calcitriol or quercetin supplementation on eggshell and bone quality of laying hens.In trial 1,72 Hy-Line Brown layers(80-week-old)with weak-shelled strength(...This study was aimed to investigate the effects of dietary calcitriol or quercetin supplementation on eggshell and bone quality of laying hens.In trial 1,72 Hy-Line Brown layers(80-week-old)with weak-shelled strength(25 to 30 N)were assigned into 4 dietary treatments with 6 replicates of 3 birds and fed a basal diet(4%calcium level)or basal diets supplemented with 0.5%calcium,5μg/kg calcitriol or 500 mg/kg quercetin for 4 weeks.In trial 2,360 Hy-Line Brown layers(60-week-old)were divided into 3 groups with 8 replicates of 15 birds:control group(basal diet),calcitriol group(basal diet+5μg/kg calcitriol),and quercetin group(basal diet+500 mg/kg quercetin).This trial lasted for 12 weeks.The results showed that dietary calcitriol or quercetin improved eggshell quality in both trials(P<0.05).In trial 2,compared with the control group,both calcitriol and quercetin supplementations improved femoral bone quality,calcium retention of hens and calcium content in uterine fluid at 18.5 h post-oviposition(PO)(P<0.05),along with enhancing uterine morphology.Compared to the control group,supplemental calcitriol or quercetin up-regulated the relative mRNA expression levels of uterine transient receptor potential cation channel,subfamily V,member 6(TRPV6)at 8.5 h PO and plasma membrane calcium-ATPase(PMCA),vitamin D receptor(VDR),estrogen receptor alpha(ERα)at 18.5 h PO(P<0.05),but down-regulated the uterine caspase 3(CASP3)relative mRNA expression level at 8.5 h PO(P<0.05).Meanwhile,the femoral relative mRNA expression levels of tartrate-resistant acid phosphatase(TRAP)(up-regulated at 8.5 and 18.5 h PO)and alkaline phosphatase(ALP)(up-regulated at 8.5 h PO but down-regulated at 18.5 h PO)were also affected by calcitriol or quercetin supplementation(P<0.05).Compared to the calcitriol,quercetin increased hen-day egg production and femoral medullary bone volume/bone tissue volume but reduced femoral stiffness(P<0.05),which were accompanied by increased relative mRNA expression levels of uterine TRPV6,estrogen receptor beta(ERβ)at 18.5 h PO(P<0.05).Overall,both dietary calcitriol and quercetin could improve eggshell and bone quality by modulating calcium metabolism of aged layers.Compared to calcitriol,dietary quercetin up-regulated the expression of uterine calcium transporters,without affecting eggshell quality.展开更多
Antinutritional factors in feedstuffs may limit their utilization in livestock production,but fermentation process can be used to improve feed quality;however,studies on fermented soybeans for laying hens remain limit...Antinutritional factors in feedstuffs may limit their utilization in livestock production,but fermentation process can be used to improve feed quality;however,studies on fermented soybeans for laying hens remain limited.We investigated the effect of fermented soybean meal(FSBM)at various inclusion levels as a partial replacement for soybean meal(SBM)on egg production,egg quality,amino acid digestibility,gut morphology and microbiota,antioxidant capacity and immune response of young laying hens.A total of 360 Hy-line Brown laying hens aged 18 weeks were selected and divided into 5 groups of 6 replicates each and 12 birds per replicate.The control group received a basal diet while the trial group received the basal diet with FSBM included at 2.5%,5.0%,7.5%and 10.0%,respectively,for 12 weeks.Our findings revealed that the nutritional value of FSBM was higher compared to that of SBM in terms of reduced content of trypsin inhibitors and increased contents of crude protein,amino acids and minerals.FSBM enhanced egg production(P<0.05),feed-to-egg ratio(P<0.05),and albumen quality(albumen height and Haugh unit)(P<0.05).Furthermore,FSBM improved apparent fecal amino acid digestibility(P<0.05),gut morphology(increased villus height,villus width,villus height-to-crypt depth ratio and decreased crypt depth)(P<0.05),antioxidant capacity(reduced malondialdehyde and increased catalase,total superoxide dismutase,glutathione peroxidase and total antioxidant capacity)(P<0.05)and immune function(increased concentrations of IgG,IgA,and IgM;increased levels of transforming growth factor beta and Toll-like receptor 2;and reduced levels of interleukin 1βand tumor necrosis factor alpha)(P<0.05).Further analysis showed that FSBM altered the composition of the gut microbiota favoring beneficial microbes.These findings suggest that probiotic fermentation improved the nutritional value of SBM.The inclusion of FSBM in the diets of laying hens at 2.5%or 5.0%improved amino acid digestibility,gut health,immune function,egg production and egg quality.展开更多
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 H...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;10^(9) 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.展开更多
This study examined the effect of dietary serine(Ser)on egg white quality,ovomucin content of laying hens fed low-gossypol cottonseed meal(LCSM)-based diet and sought to explore the regulatory mechanism underlying the...This study examined the effect of dietary serine(Ser)on egg white quality,ovomucin content of laying hens fed low-gossypol cottonseed meal(LCSM)-based diet and sought to explore the regulatory mechanism underlying the effects.A total of 288 Hy-Line Brown layers were randomly assigned into 3 treatments and respectively offered soybean meal(SBM)-based diet,LCSM-based diet,and LCSM-based diet supplemented with 0.435%L-Ser.Dietary Ser supplementation reversed the decrease in quality indices of albumen,including the proportion of thick albumen(P<0.05),thick-to-thin ratio(P<0.05),albumen height(P<0.05),Haugh unit(P<0.05),and apparent viscosity that were caused by LCSM intake.Also,dietary Ser supplementation mitigated the LCSM-induced reduction in ovomucin content of the albumen(P<0.05).FT-IR analysis of ovomucin revealed differences in second derivative spectra at 1,200-800 cm^(-1) between birds received SBM-and LCSM-based diets,meanwhile,the α-helix of ovomucin was decreased by LCSM but increased by Ser addition(P<0.05).Furthermore,Ser addition up-regulated the mRNA expression of β-ovomucin in magnum mucosa at 2 and 7.5 h post-oviposition(P<0.05).Ser mitigated the LCSMinduced impairment of magnum epithelium,increased goblet cell counts(P<0.05),and up-regulated the expression of occludin,mucin 2,and the relevant glycosyltransferases for O-glycosylation in magnum mucosa(P<0.05).Conclusively,the alleviating effect of Ser on declining albumen quality due to dietary LCSM,could be explained by the efficacy of Ser in regulating ovomucin synthesis.This regulation occurred at the levels of transcription and posttranscriptional O-glycosylation modification ofβ-ovomucin,while positive effect on magnum morphology and barrier function could also in part account for the ovomucin content.This would provide a promising research direction on the adoption of nutritional interventions for manipulation of egg white quality from perspectives of albumen protein synthesis.展开更多
This study was conducted to evaluate the prebiotic effects of dietary xylooligosaccharide(XOS)sup-plementation on performance,nutrient digestibility,intestinal morphology,and gut microbiota in laying hens.In a 12-wk e...This study was conducted to evaluate the prebiotic effects of dietary xylooligosaccharide(XOS)sup-plementation on performance,nutrient digestibility,intestinal morphology,and gut microbiota in laying hens.In a 12-wk experiment,a total of 288 Hy-Line Brown layers at 50 wk of age were randomly assigned into 3 dietary treatments supplemented with XOS at 0,200 or 400 mg/kg.Each treatment had 8 replicates with 12 birds each.Hens fed XOS diets showed a lower feed-to-egg ratio during wk 7 to 12 and a higher egg yolk color value in wk 12 compared with those fed the control diet(P<0.05).Dietary XOS supplementation improved the apparent total tract digestibility of gross energy and nitrogen at the end of the 12th wk(P<0.05).In addition,a higher villus height-to-crypt depth ratio of the ileum was observed in XOS-added groups(P<0.05).The high throughput sequencing analysis of bacterial 16S rRNA revealed that dietary XOS supplementation at 200 mg/kg altered cecal microbiota.Alpha diversity analysis illustrated a higher cecal bacterial richness in birds fed with XOS at 200 mg/kg.The composition of cecal microbiota modulated by the XOS addition was characterized by an increased abundance of Firmicutes along with a reduced abundance of Bacteroidetes.At the genus level,dietary XOS supple-mentation triggered decreases in Bacteroides and Campylobacter concurrent with increases in Lactoba-cillus and several short chain fatty acid producers including Desulfovibrio,Faecalitalea,Faecalicoccus,and 5 genera of family Lachnospiraceae.Collectively,dietary XOS addition improved the feed conversion ratio by modulating nutrient digestibility and ileal morphology in laying hens,which could be attributed to the enhancement of bacterial diversity and alteration of microbial composition.展开更多
World egg production and consumption have been increasing for the past decades. Traditional strategies in poultry nutrition have made vital contributions to this great growth in quantity. However, current global issue...World egg production and consumption have been increasing for the past decades. Traditional strategies in poultry nutrition have made vital contributions to this great growth in quantity. However, current global issues should be considered in modern egg production such as growing populations and food security, food safety and quality, limited resources and environmental problems. The development of knowledge of poultry nutrition and modern biotechnology provides novel nutritional approaches to closely fit the requirement of pullets and laying hens, which will consequently decrease the nutrition excretion and maintain the lower cost of feed. Nutrition has also been widely accepted as a strategy to influence health and diseases of laying hens. The maintenance of good health is an important prerequisite for improving productivity and egg quality. In addition, there are many measures and strategies for minimizing the incidence of egg defects and providing a choice of lifestyle to enhance human health. This paper reviews current research progress on developing innovative technologies and strategies to maximize animal health and performance, improve the quality of egg products and minimize pollution caused by poultry production.展开更多
The object of this study was to explore the regulatory mechanism of octacosanol to the body of animals and the effects of octacosanol on blood hormone levels and gene expressions of glucose transporter protein（GLUT-4...The object of this study was to explore the regulatory mechanism of octacosanol to the body of animals and the effects of octacosanol on blood hormone levels and gene expressions of glucose transporter protein（GLUT-4） and adenosine monophosphate protein kinase（AMPK） in liver and muscle tissue of weaning piglets. A total of 105 crossbred piglets（[Yorkshire x Landrace] x Duroc） with an initial BW of5.70 ± 1.41 kg（21 d of age） were used in a 6-wk trial to evaluate the effects of octacosanol and tiamulin supplementation on contents of triiodothyronine（T3）,thyroxine（T4）,growth hormone（GH）,glucagon（GU） and adrenaline（AD） in blood and gene expressions of GLUT-4 and AMPK in liver and muscle. Piglets were randomly distributed into 3 dietary treatments on the basis of BW and sex. Each treatment had 7 replicate pens with 5 piglets per pen. Treatments were as followed: control group, tiamulin group and octacosanol group. The results showed that compared with control group and tiamulin group, octacosanol greatly promoted the secretion of T3, GH, GU and AD（P < 0.01） and significantly up-regulated the gene expressions of GLUT-4 and AMPK in muscle and liver tissues（P < 0.05）. There was no significant difference between the control group and tiamulin group in T3, T4, GH,GU or AD（P> 0.05）, Results of the present study has confirmed that octacosanol affects energy metabolism of body by regulating secretion of blood hormones and related gene expression in tissue of weaning piglets, which can reduce stress response and has an impact on performance.展开更多
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)add...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-1β 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-1b 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 inflam-matory 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 for-mation,thereby determining eggshell mechanical properties.These findings provide a novel insight into the uterine inflammation-mediated modifications of eggshell quality.展开更多
This study was conducted to evaluate the effects of various protein sources(soybean meal, SBM; cottonseed protein, CSP; double-zero rapeseed meal, DRM) on the internal quality(Haugh unit, yolk index,albumen pH,yolk ha...This study was conducted to evaluate the effects of various protein sources(soybean meal, SBM; cottonseed protein, CSP; double-zero rapeseed meal, DRM) on the internal quality(Haugh unit, yolk index,albumen pH,yolk hardness and yolk springiness) of eggs when stored at either 4 or 28℃ for 28 d. A total of 288 laying hens(32 wk of age) were randomly allotted to 6 treatment groups(4 replicates per treatment) and fed diets containing SBM, CSP, or DRM individually or in combination with equal crude protein content(SBM-CSP, SBM-DRM, and CSP-DRM) as the protein ingredient(s). A 6 x 2 factorial arrangement was employed with dietary types and storage temperatures(4 and 28℃) as the main effects. After 12 wk of diet feeding, a total of 216 eggs was collected for egg internal quality determination.The results showed as follows: 1) lower egg quality was observed in the DRM group compared with the other groups when stored at 4 and 28℃ for 28 d(P < 0.05), while there was no difference in egg internal quality among the other groups. 2) The CSP diet resulted in higher yolk hardness compared with the other diets when eggs were stored at 4℃ for 28 d(P < 0.05). Lower Haugh unit was observed in the DRM and SBM-DRM groups compared with the other groups when eggs were stored for 28 d at 4℃(P < 0.05).3) Yolk breakage occurred in the DRM group and eggs could not be analyzed for egg internal quality when stored at 28℃ for 28 d. The overall results indicated that CSP or DRM as the sole dietary protein source for laying hens may adversely affect the internal quality of stored eggs as compared with the SBM diet, and half replacement of CSP combined with SBM may maintain similar egg quality to SBM diet alone for eggs stored under refrigerated conditions.展开更多
基金This study was supported by the National Natural Science Foundation of China(32172743)China Agriculture Research System(CARS-40)the Agricultural Science and Technology Innovation Program(ASTIP)of CAAS.
文摘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 physiologi-cal 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 24074-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 osteocal-cin 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.
基金supported by Shandong Key Science and Technology Innovation Program(2019JZZY010704)China Agriculture Research System(CARS-40-K12)+1 种基金Beijing Innovation Consortium of Agriculture Research System(BAIC04-2020)Agricultural Science and Technology Innovation Program(ASTIP)of the Chinese Academy of Agricultural Sciences.
文摘Background:Dietary essential oil(EO)supplementation can exert favorable effects on gut health in broilers.However,it is unknown whether EO could improve intestinal functions,consequently beneficial for egg performance and quality in late-phase laying hens.This study was aimed to investigate the potential effects of EO on production performance,egg quality,intestinal health and ileal microbiota of hens in the late phase of production.A total of 28860-week-old Hy-line Brown laying hens were randomly divided into 4 groups and fed a basal diet(control)or basal diets supplemented with oregano EO at 100,200 and 400 mg/kg(EO100,EO200 and EO400).Results:Dietary EO supplementation resulted in a quadratic decrease(P<0.05)in feed conversion ratio with lower(P<0.05)feed conversion ratio in EO200 group than the control during weeks 9–12 and 1–12 of the trial.Compared to the control,EO addition resulted in higher(P<0.05)eggshell thickness at the end of week.4,8 and 12 and higher(P<0.05)chymotrypsin activity.There was a quadratic elevation(P<0.05)in ileal chymotrypsin and lipase activity,along with a linear increase in villus height to crypt depth ratio.Quadratic declines(P<0.05)in mRNA expression of IL-1β,TNF-α,IFN-γ and TLR-4,concurrent with a linear and quadratic increase(P<0.05)in ZO-1 expression were identified in the ileum with EO addition.These favorable effects were maximized at medium dosage(200 mg/kg)of EO addition and intestinal microbial composition in the control and EO200 groups were assessed.Dietary EO addition increased(P<0.05)the abundances of Burkholderiales,Actinobacteria,Bifidobacteriales,Enterococcaceae and Bacillaceae,whereas decreased Shigella abundance in the ileum.Conclusions:Dietary EO addition could enhance digestive enzyme activity,improve gut morphology,epithelial barrier functions and modulate mucosal immune status by altering microbial composition,thus favoring feed efficiency and eggshell quality of late-phase laying hens.
基金financed by the National Natural Science Foundation of China(NSFC)(31601978)the China Agriculture Research System-Beijing Team for Poultry Industrythe Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Background: Meat color and lipid peroxidation are important traits related to meat quality. CO_2 concentration is a critical factor that can affect meat quality in the commercial use of gas stunning(GS). However, the effect and mechanism of CO_2 stunning on meat color and lipid peroxidation during long-term storage remain poorly studied. We aimed to study the effects of GS methods, especial y CO_2 concentration, on meat color and meat lipid peroxidation in broilers during long-term storage at 4 °C and to explore the potential mechanism of meat color change via lipid peroxidation and the inner lipid peroxide scavenging system.Methods: Eighteen broilers were sacrificed after exposure to one of the following gas mixtures for 90 s: 40% CO_2+21% O_2+ 39% N2(G40%), 79% CO_2+ 21% O_2(G79%), or no stunning(0% CO_2, control). Meat color, serum variables,enzyme activities, and the gene expression of mitogen-activated protein kinase(MAPK), nuclear factor-erythroid2-related factor 2(Nrf2), glutathione S-transferase(GST) and superoxide dismutase(SOD) were determined.(Continued on next page)Results: The concentrations of serum triiodothyronine(T3, P = 0.03) and the ratio of serum free triiodothyronine/free thyroxine(FT3/FT4, P < 0.01) were decreased, whereas levels of serum cortisol(P < 0.01) were increased in the 40%CO_2 group compared with the control group. Additionally, the thiobarbituric acid-reactive substances(TBARS)3 d(P < 0.01) and TBARS6 d(P = 0.01) in breast meat and the TBARS3 din thigh meat(P < 0.01) were increased in the40% CO_2 group compared with the control group. Serum T3 was negatively correlated with TBARS6 dboth in the breast and thigh meat(r =-0.63, P < 0.01 and r =-0.47, P = 0.05 respectively). T3/T4 was negatively correlated with TBARS6 din the breast meat and in the thigh meat(r =-0.57, P = 0.01; and r =-0.53, P = 0.03 respectively). Compared with the control group, Lightness(L*)1 d(P = 0.03) and L*9 d(P < 0.01) were increased, whereas total chromatic aberration(E*)1 d(P = 0.05) and E*3 d(P < 0.01) were decreased in the breast meat of both the G40% and G79% groups. The values of yel owness(b*)3 d(P = 0.01), b*6 d(P < 0.01) and E*6 d(P < 0.01) in the thigh meat were lower in both the G40% and G79% groups than in the control group. In the breast muscle, the m RNA levels of c-Jun N-terminal kinase 2(JNK2, P = 0.03),GSTT1(P = 0.04), and SOD1(P = 0.05) were decreased, and the m RNA levels of JNK1(P = 0.07), Nrf2(P = 0.09), and GSTA3(P = 0.06) were slightly lower in both the G40% and G79% groups compared with the control group. However, among these genes, only the m RNA level of JNK1 was decreased in the G40% group compared with the control group and the G79% group(P = 0.03) in the thigh muscle.Conclusions: Compared with the control group, meat color quality in the breast meat was decreased, and the expression of genes in the MAPK/Nrf2/ARE(antioxidant responsive element) antioxidant pathway in breast muscle was partly suppressed by GS of both 40% and 79% CO_2. However, oxidative stress and meat lipid peroxidation during storage were aggravated by GS with 40% CO_2 compared to GS with 79% CO_2 and no GS.
基金supported by the Agricultural Science and Technology Innovation Program(ASTIP)of the Chinese Academy of Agricultural Sciences,and Trouw Nutrition Research&Development Centers.
文摘Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed addi-tives for their ability to improve growth performance and intestinal health in poultry.However,whether dietary OA can ameliorate HSD stress-induced impaired intestinal barrier in broilers remains elusive.In this study,a total of 528 one-day-old male Arbor Acres broilers were randomly allocated into 3 treatments with 12 replicates per treatment including 10 birds for normal stocking density and 17 birds for HSD.The dietary treatments were as follows:1)Normal stocking density+basal diet;2)HSD+basal diets;3)HSD+OA.Results:HSD stress can induce increased levels of serum corticosterone,lipopolysaccharides,interleukin-1β,tumor necrosis factor-α,and down-regulated mRNA expression of ZO-1,resulting in compromised growth performance of broilers(P<0.05).Dietary OA could significantly reduce levels of serum corticosterone,lipopolysaccharides,interleukin-1β,and tumor necrosis factor-α,which were accompanied by up-regulated interleukin-10,mRNA expres-sion of ZO-1,and growth performance(P<0.05).Moreover,OA could down-regulate the mRNA expression of TLR4 and MyD88 to inhibit the NF-κB signaling pathway(P<0.05).Additionally,HSD stress significantly decreased the abundance of Bacteroidetes and disturbed the balance of microbial ecosystems,whereas OA significantly increased the abundance of Bacteroidetes and restored the disordered gut microbiota by reducing competitive and exploita-tive interactions in microbial communities(P<0.05).Meanwhile,OA significantly increased the content of acetic and butyric acids,which showed significant correlations with intestinal inflammation indicators(P<0.05).Conclusions:Dietary OA ameliorated intestinal inflammation and growth performance of broilers through restor-ing the disordered gut microbial compositions and interactions induced by HSD and elevating short-chain fatty acid production to inhibit the TLR4/NF-κB signaling pathway.These findings demonstrated the critical role of intestinal microbiota in mediating the HSD-induced inflammatory responses,contributing to exploring nutritional strategies to alleviate HSD-induced stress in animals.
基金supported by the National Natural Science Foundation of China (32172743)the eammarked fund for China Agriculture Research Systems (CARS-40)the Agricultural Science and Tec hnology Innovation Program (ASTIP)of CAAS.
文摘This study was aimed to investigate the effects of dietary calcitriol or quercetin supplementation on eggshell and bone quality of laying hens.In trial 1,72 Hy-Line Brown layers(80-week-old)with weak-shelled strength(25 to 30 N)were assigned into 4 dietary treatments with 6 replicates of 3 birds and fed a basal diet(4%calcium level)or basal diets supplemented with 0.5%calcium,5μg/kg calcitriol or 500 mg/kg quercetin for 4 weeks.In trial 2,360 Hy-Line Brown layers(60-week-old)were divided into 3 groups with 8 replicates of 15 birds:control group(basal diet),calcitriol group(basal diet+5μg/kg calcitriol),and quercetin group(basal diet+500 mg/kg quercetin).This trial lasted for 12 weeks.The results showed that dietary calcitriol or quercetin improved eggshell quality in both trials(P<0.05).In trial 2,compared with the control group,both calcitriol and quercetin supplementations improved femoral bone quality,calcium retention of hens and calcium content in uterine fluid at 18.5 h post-oviposition(PO)(P<0.05),along with enhancing uterine morphology.Compared to the control group,supplemental calcitriol or quercetin up-regulated the relative mRNA expression levels of uterine transient receptor potential cation channel,subfamily V,member 6(TRPV6)at 8.5 h PO and plasma membrane calcium-ATPase(PMCA),vitamin D receptor(VDR),estrogen receptor alpha(ERα)at 18.5 h PO(P<0.05),but down-regulated the uterine caspase 3(CASP3)relative mRNA expression level at 8.5 h PO(P<0.05).Meanwhile,the femoral relative mRNA expression levels of tartrate-resistant acid phosphatase(TRAP)(up-regulated at 8.5 and 18.5 h PO)and alkaline phosphatase(ALP)(up-regulated at 8.5 h PO but down-regulated at 18.5 h PO)were also affected by calcitriol or quercetin supplementation(P<0.05).Compared to the calcitriol,quercetin increased hen-day egg production and femoral medullary bone volume/bone tissue volume but reduced femoral stiffness(P<0.05),which were accompanied by increased relative mRNA expression levels of uterine TRPV6,estrogen receptor beta(ERβ)at 18.5 h PO(P<0.05).Overall,both dietary calcitriol and quercetin could improve eggshell and bone quality by modulating calcium metabolism of aged layers.Compared to calcitriol,dietary quercetin up-regulated the expression of uterine calcium transporters,without affecting eggshell quality.
基金supported by Beijing Innovation Consortium of Agriculture Research System,the National Key Research and Development Program of China (2022YFC2105005)the National Natural Science Foundation of China (32072774)the Agricul-tural Science and Technology Innovation Program (CAAS-ZDRW202111).
文摘Antinutritional factors in feedstuffs may limit their utilization in livestock production,but fermentation process can be used to improve feed quality;however,studies on fermented soybeans for laying hens remain limited.We investigated the effect of fermented soybean meal(FSBM)at various inclusion levels as a partial replacement for soybean meal(SBM)on egg production,egg quality,amino acid digestibility,gut morphology and microbiota,antioxidant capacity and immune response of young laying hens.A total of 360 Hy-line Brown laying hens aged 18 weeks were selected and divided into 5 groups of 6 replicates each and 12 birds per replicate.The control group received a basal diet while the trial group received the basal diet with FSBM included at 2.5%,5.0%,7.5%and 10.0%,respectively,for 12 weeks.Our findings revealed that the nutritional value of FSBM was higher compared to that of SBM in terms of reduced content of trypsin inhibitors and increased contents of crude protein,amino acids and minerals.FSBM enhanced egg production(P<0.05),feed-to-egg ratio(P<0.05),and albumen quality(albumen height and Haugh unit)(P<0.05).Furthermore,FSBM improved apparent fecal amino acid digestibility(P<0.05),gut morphology(increased villus height,villus width,villus height-to-crypt depth ratio and decreased crypt depth)(P<0.05),antioxidant capacity(reduced malondialdehyde and increased catalase,total superoxide dismutase,glutathione peroxidase and total antioxidant capacity)(P<0.05)and immune function(increased concentrations of IgG,IgA,and IgM;increased levels of transforming growth factor beta and Toll-like receptor 2;and reduced levels of interleukin 1βand tumor necrosis factor alpha)(P<0.05).Further analysis showed that FSBM altered the composition of the gut microbiota favoring beneficial microbes.These findings suggest that probiotic fermentation improved the nutritional value of SBM.The inclusion of FSBM in the diets of laying hens at 2.5%or 5.0%improved amino acid digestibility,gut health,immune function,egg production and egg quality.
基金financed by the National Key Research and Development Program of China (2021YFD1300300)the National Natural Science Foundation of China (32202697)+1 种基金Key Technology Research and Development Program of Henan Province (232102111041)the Innovation Fund of Henan University of Technology (2022ZKCJ17).
文摘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;10^(9) 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.
基金financially supported by the National Natural Science Foundation of China(32072774)the China Postdoctoral Science Foundation(2023M733822)+2 种基金the Beijing Innovation Consortium of Agriculture Research System(BAIC04),Chinathe earmarked fund for CARS National System for Layer Production Technology,China(CARS-40)the Agricultural Science and Technology Innovation Program(ASTIP)of the Chinese Academy of Agricultural Sciences。
文摘This study examined the effect of dietary serine(Ser)on egg white quality,ovomucin content of laying hens fed low-gossypol cottonseed meal(LCSM)-based diet and sought to explore the regulatory mechanism underlying the effects.A total of 288 Hy-Line Brown layers were randomly assigned into 3 treatments and respectively offered soybean meal(SBM)-based diet,LCSM-based diet,and LCSM-based diet supplemented with 0.435%L-Ser.Dietary Ser supplementation reversed the decrease in quality indices of albumen,including the proportion of thick albumen(P<0.05),thick-to-thin ratio(P<0.05),albumen height(P<0.05),Haugh unit(P<0.05),and apparent viscosity that were caused by LCSM intake.Also,dietary Ser supplementation mitigated the LCSM-induced reduction in ovomucin content of the albumen(P<0.05).FT-IR analysis of ovomucin revealed differences in second derivative spectra at 1,200-800 cm^(-1) between birds received SBM-and LCSM-based diets,meanwhile,the α-helix of ovomucin was decreased by LCSM but increased by Ser addition(P<0.05).Furthermore,Ser addition up-regulated the mRNA expression of β-ovomucin in magnum mucosa at 2 and 7.5 h post-oviposition(P<0.05).Ser mitigated the LCSMinduced impairment of magnum epithelium,increased goblet cell counts(P<0.05),and up-regulated the expression of occludin,mucin 2,and the relevant glycosyltransferases for O-glycosylation in magnum mucosa(P<0.05).Conclusively,the alleviating effect of Ser on declining albumen quality due to dietary LCSM,could be explained by the efficacy of Ser in regulating ovomucin synthesis.This regulation occurred at the levels of transcription and posttranscriptional O-glycosylation modification ofβ-ovomucin,while positive effect on magnum morphology and barrier function could also in part account for the ovomucin content.This would provide a promising research direction on the adoption of nutritional interventions for manipulation of egg white quality from perspectives of albumen protein synthesis.
基金National Key R&D Program of China(2018YFD0500603)China Agricultural Research System(CARS40-K12)the China Agriculture Research System-Beijing Team for Poultry Industry and the Agricultural Science and Technology Innovation Program(ASTIP)of the Chinese Academy of Agricultural Sciences.
文摘This study was conducted to evaluate the prebiotic effects of dietary xylooligosaccharide(XOS)sup-plementation on performance,nutrient digestibility,intestinal morphology,and gut microbiota in laying hens.In a 12-wk experiment,a total of 288 Hy-Line Brown layers at 50 wk of age were randomly assigned into 3 dietary treatments supplemented with XOS at 0,200 or 400 mg/kg.Each treatment had 8 replicates with 12 birds each.Hens fed XOS diets showed a lower feed-to-egg ratio during wk 7 to 12 and a higher egg yolk color value in wk 12 compared with those fed the control diet(P<0.05).Dietary XOS supplementation improved the apparent total tract digestibility of gross energy and nitrogen at the end of the 12th wk(P<0.05).In addition,a higher villus height-to-crypt depth ratio of the ileum was observed in XOS-added groups(P<0.05).The high throughput sequencing analysis of bacterial 16S rRNA revealed that dietary XOS supplementation at 200 mg/kg altered cecal microbiota.Alpha diversity analysis illustrated a higher cecal bacterial richness in birds fed with XOS at 200 mg/kg.The composition of cecal microbiota modulated by the XOS addition was characterized by an increased abundance of Firmicutes along with a reduced abundance of Bacteroidetes.At the genus level,dietary XOS supple-mentation triggered decreases in Bacteroides and Campylobacter concurrent with increases in Lactoba-cillus and several short chain fatty acid producers including Desulfovibrio,Faecalitalea,Faecalicoccus,and 5 genera of family Lachnospiraceae.Collectively,dietary XOS addition improved the feed conversion ratio by modulating nutrient digestibility and ileal morphology in laying hens,which could be attributed to the enhancement of bacterial diversity and alteration of microbial composition.
基金supported by the China Agriculture Research System(CARS-41-K13)China Agriculture Research System-Beijing Team for Poultry Industry
文摘World egg production and consumption have been increasing for the past decades. Traditional strategies in poultry nutrition have made vital contributions to this great growth in quantity. However, current global issues should be considered in modern egg production such as growing populations and food security, food safety and quality, limited resources and environmental problems. The development of knowledge of poultry nutrition and modern biotechnology provides novel nutritional approaches to closely fit the requirement of pullets and laying hens, which will consequently decrease the nutrition excretion and maintain the lower cost of feed. Nutrition has also been widely accepted as a strategy to influence health and diseases of laying hens. The maintenance of good health is an important prerequisite for improving productivity and egg quality. In addition, there are many measures and strategies for minimizing the incidence of egg defects and providing a choice of lifestyle to enhance human health. This paper reviews current research progress on developing innovative technologies and strategies to maximize animal health and performance, improve the quality of egg products and minimize pollution caused by poultry production.
基金provided by China Agriculture Research System-Beijing Team for Poultry Industry(CARS-PSTP)the National Science&Technology Pillar Program(2011BAD26B04,Beijing,China)
文摘The object of this study was to explore the regulatory mechanism of octacosanol to the body of animals and the effects of octacosanol on blood hormone levels and gene expressions of glucose transporter protein（GLUT-4） and adenosine monophosphate protein kinase（AMPK） in liver and muscle tissue of weaning piglets. A total of 105 crossbred piglets（[Yorkshire x Landrace] x Duroc） with an initial BW of5.70 ± 1.41 kg（21 d of age） were used in a 6-wk trial to evaluate the effects of octacosanol and tiamulin supplementation on contents of triiodothyronine（T3）,thyroxine（T4）,growth hormone（GH）,glucagon（GU） and adrenaline（AD） in blood and gene expressions of GLUT-4 and AMPK in liver and muscle. Piglets were randomly distributed into 3 dietary treatments on the basis of BW and sex. Each treatment had 7 replicate pens with 5 piglets per pen. Treatments were as followed: control group, tiamulin group and octacosanol group. The results showed that compared with control group and tiamulin group, octacosanol greatly promoted the secretion of T3, GH, GU and AD（P < 0.01） and significantly up-regulated the gene expressions of GLUT-4 and AMPK in muscle and liver tissues（P < 0.05）. There was no significant difference between the control group and tiamulin group in T3, T4, GH,GU or AD（P> 0.05）, Results of the present study has confirmed that octacosanol affects energy metabolism of body by regulating secretion of blood hormones and related gene expression in tissue of weaning piglets, which can reduce stress response and has an impact on performance.
基金supported by the National Natural Science Foundation of China(31872396,32172743)China Agriculture Research System(CARS-40),and the Agricultural Science and Technology Innovation Program(ASTIP)of the Chinese Academy of Agricultural Sciences.
文摘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-1β 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-1b 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 inflam-matory 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 for-mation,thereby determining eggshell mechanical properties.These findings provide a novel insight into the uterine inflammation-mediated modifications of eggshell quality.
基金supported by the China Agriculture Research System(CARS-41-K13)the Agricultural Science and Technology Innovation Program(ASTIP)+1 种基金National Key Technology Research and Development Program(2011BAD26B03)China Agriculture Research System-Beijing Team for the Poultry Industry
文摘This study was conducted to evaluate the effects of various protein sources(soybean meal, SBM; cottonseed protein, CSP; double-zero rapeseed meal, DRM) on the internal quality(Haugh unit, yolk index,albumen pH,yolk hardness and yolk springiness) of eggs when stored at either 4 or 28℃ for 28 d. A total of 288 laying hens(32 wk of age) were randomly allotted to 6 treatment groups(4 replicates per treatment) and fed diets containing SBM, CSP, or DRM individually or in combination with equal crude protein content(SBM-CSP, SBM-DRM, and CSP-DRM) as the protein ingredient(s). A 6 x 2 factorial arrangement was employed with dietary types and storage temperatures(4 and 28℃) as the main effects. After 12 wk of diet feeding, a total of 216 eggs was collected for egg internal quality determination.The results showed as follows: 1) lower egg quality was observed in the DRM group compared with the other groups when stored at 4 and 28℃ for 28 d(P < 0.05), while there was no difference in egg internal quality among the other groups. 2) The CSP diet resulted in higher yolk hardness compared with the other diets when eggs were stored at 4℃ for 28 d(P < 0.05). Lower Haugh unit was observed in the DRM and SBM-DRM groups compared with the other groups when eggs were stored for 28 d at 4℃(P < 0.05).3) Yolk breakage occurred in the DRM group and eggs could not be analyzed for egg internal quality when stored at 28℃ for 28 d. The overall results indicated that CSP or DRM as the sole dietary protein source for laying hens may adversely affect the internal quality of stored eggs as compared with the SBM diet, and half replacement of CSP combined with SBM may maintain similar egg quality to SBM diet alone for eggs stored under refrigerated conditions.
