Use of encapsulated L-lysine-HCl and DL-methionine improves postprandial amino acid balance in laying hens

Effects of different forms of amino acid supplementation on the performance and intestinal barrier function of laying hens fed a low-protein diet

The aim of this study was to investigate the effects of low-protein diets and the sustained release of synthetic amino acids (AA) on the performance, intestinal barrier function and nitrogen excretion of laying hens. Two hundred eighty-eight 39-week-old Hyline brown laying hens of were randomly divided into 3 groups with 8 replicates per group. The crude protein level in the control group (CON) was 16%, the crude protein levels in the crystal AA supplement group (LCP-CAA) and microencapsulated AA group (LCP-MAA) were both 13%, and the AA levels in the LCP-CAA and LCP-MAA groups were consistent with that in the CON group. The experiment lasted 12 wk, and production performance was assessed weekly. The FCR and ADFI values were significantly greater for the LCP-CAA group than for the CON and LCP-MAA groups (P < 0.05). Two hours after feeding, His levels were significantly greater in the LCP-CAA group than in the LCP-MAA group (P < 0.05); 4 h after feeding, the contents of Met, Thr, Leu and Val were significantly greater in blood from the LCP-MAA group (P < 0.05); 6 h after feeding, Trp, Ile and Arg levels were significantly greater in the LCP-MAA group (P < 0.05). The chylase content significantly decreased in the duodenum of the LCP-CAA group (P < 0.05), and the chylase and trypsin were contents increased in the ileum of the LCP-MAA group (P < 0.05). In the LCP-MAA group, significantly increased mRNA expression levels of Occludin, ZO-1 in duodenum; Occludin, ZO-1, y+LAT1 in jejunum; and ZO-1 in ileum were detected at 8 and 12 weeks (P < 0.05). The fecal nitrogen content significantly decreased in the low protein diet group (P < 0.01). In conclusion, reducing dietary crude protein levels and supplementing with microencapsulated AAs can improve intestinal barrier function, promote digestive enzyme secretion, increase the expression of AA transporters, improve dietary protein utilization efficiency, and reduce nitrogen emission in laying hens.

Effects of L-Methionine and DL-Methionine on Growth Performance, Methionine-Metabolizing Enzyme Activities, Feather Traits, and Intestinal Morphology of Medium-Growing, Yellow-Feathered Chickens between 1 and 30 Days of Age

This experiment investigated the effects of L-Methionine (L-Met) on growth performance, Met-metabolizing enzyme activity, feather traits, and small intestinal morphological characteristics, and compared these with DL-Methionine (DL-Met) for medium-growing, yellow-feathered broilers during the starter phase. Furthermore, the aim was to provide recommendations for the appropriate dietary Met levels in feed. A total of 1584 1-d broilers were randomly divided into 11 treatment groups with six replicates of 24 birds each: basal diet (CON, Met 0.28%), basal diet + L-Met (0.04%, 0.08%, 0.12%, 0.16%, 0.20%), and basal diet + DL-Met (0.04%, 0.08%, 0.12%, 0.16%, 0.20%). The total trial period was 30 days. Compared with broilers fed the basal diet, those fed 0.04 to 0.20% supplemental Met had higher final body weight (FBW), average daily feed intake (ADFI), average daily gain (ADG), and lower feed-to-gain ratio (F: G) (p < 0.05). Compared with DL-Met groups, the L-Met group had higher FBW and ADG (p < 0.05). The relative bioavailability (RBV) of L-Met in ADG of 1-30 d was 142.5%. Chicks fed diets supplemented with L-Met had longer fourth primary feather lengths compared to birds fed the control and diets supplemented with DL-Met (p < 0.05). Compared to the control, birds supplemented with DL-Met or L-Met had an increased moulting score (p ≤ 0.05). Chicks fed diets supplemented with L-Met had lower activities of methionine adenosyl transferase (MAT) compared to those fed the basal diet or supplemented with DL-Met (p < 0.05). Chicks supplemented with either DL-Met or L-Met had higher activities of cystathionine β-synthase (CBS) than those fed the basal diet (p < 0.05). Compared with the control, chicks fed diets supplemented with either DL-Met or L-Met had an enhanced level of albumin in plasma (p < 0.05). There were no obvious differences in the plasma content of uric acid and total protein among the treatments (p > 0.05). Chicks fed diets supplemented with either DL-Met or L-Met had higher villus height and V/C in the duodenal than chicks fed the basal diet (p < 0.05). The jejunum morphology was not affected by either L-Met or DL-Met supplementation (p > 0.05). Therefore, dietary supplementation with DL-Met or L-Met improved the growth performance, feather traits, and intestinal morphological characteristics of medium-growing, yellow-feathered broiler chickens aged 1 to 30 d by decreasing the enzyme activities of Met methylation (MAT) and increasing the enzyme activities of the sulfur transfer pathway (CBS), and supplementation with L-Met showed a better improvement compared with DL-Met. The relative efficacy of L-Met to DL-Met was 142.5% for ADG of yellow-feathered broilers. The appropriate Met levels for medium-growing, yellow-feathered broilers are between 0.36~0.38% (supplementation with DL-Met) or 0.32~0.33% (supplementation with L-Met) when based on ADG and feed-to-gain ratio.

Effects of low dietary calcium and lipopolysaccharide challenges on production performance, eggshell quality, and bone metabolism of laying hens

Dietary calcium supply is essential for bone development and egg production in laying hens. This study investigated the effects of low dietary calcium and lipopolysaccharide (LPS) induced immune challenge in aged laying hens. A total of thirty-two Hy-Line Brown laying hens at 80 weeks old with an average laying rate of 62% were randomly divided into two groups and fed a normal calcium diet (3.57% Ca, NCA) or low calcium diet (2.08% Ca, LCA). At 88 weeks, the experiment was designed using a 2 × 2 factorial arrangement, and hens were intraperitoneally injected with saline (SAL) or LPS (0.5 mg/kg, 0.5 mg/kg, or 1.5 mg/kg body weight) once every 48 h intervals over 5 days. Production performance, egg quality, and bone physiology were evaluated. Results showed that LPS challenge decreased the hen-day egg production, egg mass, and eggshell traits (p < 0.05), but increased (p < 0.05) the calcium content of the tibia compared to SAL-injected hens. LCA diet decreased (p < 0.05) the hen-day egg production, and eggshell traits such as weight, percentage, strength, and thickness compared to the NCA diet. LCA diet increased the serum alkaline phosphatase (ALP) activity (p < 0.01) and tibial expression of ALP (p < 0.05) compared to NCA diet. LPS injection suppressed both the serum ALP activity (p < 0.05) and tibial expression of ALP (p < 0.001) compared to SAL injection. Furthermore, LPS injection increased (p < 0.05) the expression of both pro and anti-inflammatory cytokines in the spleen and tibia. The expression of cathepsin K ( Cts K ) and matrix metalloproteinase 9 ( MMP-9 ) were downregulated by LPS injection (p < 0.001). Broken and shell-less egg production and calcium content of eggshell, as well as tibial mRNA expression of osteocalcin ( Ocn ), tumor necrosis factor-alpha ( TNF-α ) and tartrate-resistant acid phosphatase ( TRAP ) were affected by the interaction (p < 0.05) of diet and injection. Therefore, this study demonstrated that to certain extents, low dietary calcium and LPS challenge dysregulated bone homeostasis and metabolism, with detrimental effects on the performance and eggshell quality of aged laying hens.

Effect of exogenous bile salts supplementation on the performance and hepatic lipid metabolism of aged laying hens

Bile acids (BA), a series of hydroxylated steroids secreted by the liver, are involved in the digestion and absorption of dietary fats. In the present study, the effect of exogenous BAs on the performance and liver lipid metabolism of laying hens was investigated. Three hundred and sixty 50-wk-old Hy-line Brown hens were randomly allocated into three groups and subjected to one of the following treatments: fed with the basal diet (control, Con), the basal diet supplemented with 0.1 g/kg (0.1 g/kg BAs), or 0.2 g/kg (0.2 g/kg BAs) porcine BAs. Laying performance, egg quality, and blood parameters were measured during the 8-wk experimental period. The expression of genes related to hepatic lipid metabolism was determined at the end of experiment. The results showed that BAs treatments had no influence (P > 0.05) on laying rate, egg weight, and feed efficiency. BAs treatment, however, significantly decreased mortality of hens (P = 0.006). BAs treatment showed a transient negative influence on eggshell quality at week 4 but not at week 8. The yolk color on week 8 was increased by BAs treatments (P < 0.0001) compared to control. The duodenum index showed a tendency to be increased (P = 0.053) and jejunum index were increased (P = 0.007) by BAs treatment. Compared to control, BAs treatments decreased lipid droplet content (P < 0.0001) and TG content (P = 0.002) of liver. Fatty acid synthase activity was also decreased as an effect of BAs dietary supplementation. Compared to the control group, 0.1 g/kg BAs treatment increased (P < 0.05) the mRNA expression of genes Farnesoid X receptor (FXR) (P = 0.042), cytochrome P450 family 7 subfamily A member 1 (CYP7A1) (P = 0.002), and cytochrome P450 family 8 subfamily B member 1 (CYP8B1) (P = 0.017), fatty acid synthase (FAS) (P = 0.020), acetyl-CoA carboxylase (ACC) (P = 0.032), sterol regulatory element binding protein-1c (SREBP-1c) (P = 0.037), proliferator-activated receptor gamma (PPARγ) (P = 0.002), apolipoprotein B (APO-B) (P = 0.020), and very low density lipoprotein receptor (VLDLR) (P = 0.024). In conclusion, the addition of exogenous BAs reduces lipid accumulation in liver. BA supplementation reduces the mortality of hens and improves egg yolk color, with no unfavorable effect on laying performance. The result suggests that suppressed FAS activity is involved in the reduced hepatic lipid accumulation by BAs treatment.

Effect of substitution of taurine for methionine and additional taurine supplementation on the performance and antioxidative capacity of laying hens

Taurine (TAU), a sulfur-containing amino acid that synthesized from methionine and cystine, plays vital roles in maintenance of redox balance. The effect of substitution of TAU for methionine was evaluated in vivo and in vitro. The effects of replacing methionine with TAU and additional TAU supplementation on the performance and antioxidant capacity of laying hens were evaluated. The in vitro cultured chicken primary hepatocytes and intestinal epithelial cells were further employed. Two hubdred eighty-eight 40-wk-old Isa brown laying hens were divided into 4 groups and subjected one to the following treatments: fed with basal diet with 0.17% crystallized DL-Met (CON), the control diet and replace 25% (21% total Met, 21TAU) or 50% (42% total Met, 42TAU) of crystallized DL-Met with taurine, the control diet supplemented with 0.1% taurine (0.1% TAU). The laying rate, feed intake, egg weight, and feed efficiency were not influenced (P > 0.05) by TAU replacement or additional TAU supplementation. In the liver, 0.1% TAU decreased SOD but increased GSH-Px activity (P < 0.01). In duodenum, 42TAU decreased SOD activity (P < 0.05) while 0.1% TAU decreased GSH level and SOD activity (P < 0.05). In the hepatocytes, TAU treatment decreased (P < 0.05) the MDA and GSH contents, whereas increased SOD and GSH-Px activities (P < 0.05). Meanwhile, TAU treatment decreased (P < 0.05) the protein expression of Nrf2 while increase Keap1 expression. The mRNA expression of Nrf2, SOD1, SOD2, CAT, and GCLC were increased (P < 0.05) and GSR were decreased (P < 0.05) by 0.1% TAU. In the intestinal epithelial cells, TAU treatment decreased (P < 0.05) SOD activity, increased (P < 0.05) CAT activity, and decreased (P < 0.05) the mRNA and protein expression of Nrf2. In summary, partial substitution methionine for taurine (21-42%) has no influence on egg performance of hens. Taurine enhances the antioxidative capacity in hepatocyte but not in the enterocytes and if taurine could offer an improved effect on antioxidant capacity needs to be verified under oxidative stress-challenged conditions.

The optimal dietary arginine level of laying hens fed with low-protein diets

Background

Arginine (Arg) is an essential amino acid (EAA) in poultry, an important substrate for protein synthesis and a precursor of several molecules. Supplementation of EAAs with low protein (LP) diet increases the utilization efficiency of dietary crude protein (CP). However, if the EAA requirement is changed in hens fed a LP diet remains to be elucidated. The aim of the present study was to evaluate the optimal level of dietary Arg in the LP diet of hens. A total of 1350 Hy-Line Brown laying hens were randomly allocated to six dietary treatments: a basal diet (16% CP, positive control), or an isoenergetic LP diet (14% CP, 0.80% Arg) supplemented 0, 0.05%, 0.10%, 0.15%, and 0.20% L-Arg, corresponding to 0.80%, 0.85%, 0.90%, 0.95% and 1.00% dietary Arg, respectively.

Results

The feed efficiency was decreased (P < 0.05) by 0.80% and 1.00% Arg-LP diets, compared to control. Within LP diets, dietary Arg level had significant quadratic effects (P < 0.05) on laying rate, egg mass, and feed efficiency. Compared to control, the plasma CAT activity or T-AOC content were decreased by 0.80% (P < 0.001). However, the hens offered 0.85% and 0.90% Arg-LP diets had higher CAT activity (P < 0.001) than 0.80% Arg-LP diet. In contrast, 1.00% Arg-LP group had the highest MDA and the lowest T-AOC content in plasma, liver, duodenal and jejunal mucosa (P < 0.05). Compared to control, the villus height was decreased by 0.80%, 0.95% and 1.00% Arg-LP diets, while the villus height to crypt depth (V/C) ratio was reduced by 0.95% and 1.00% Arg-LP diets in duodenum.

Conclusion

The result demonstrates that LP diet (14% CP) deficient in Arg (0.80% Arg) result in augmented oxidative damage and impaired development of intestinal mucosa. According to the quadratic broken-line regression model, the optimal dietary arginine levels for Hy-Line Brown laying hens fed with low protein diet (14% CP) aged 33 to 40 weeks are 0.85%, 0.86%, and 0.86% to obtained the maximum laying rate, egg mass, and feed efficiency, respectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-022-00719-x.

Effect of Methionine Deficiency on the Growth Performance, Serum Amino Acids Concentrations, Gut Microbiota and Subsequent Laying Performance of Layer Chicks

This study was conducted to investigate the effect of methionine (Met) deficiency in the rearing period on the growth performance, amino acids metabolism, intestinal development and gut microbiome of egg-laying chicks and the continuous effects on the performance, egg quality, and serum amino acids metabolism of the subsequent development process. Three hundred sixty one-day-old chicks were randomly divided into two groups and fed on a basal diet (NC group, Met 0.46%) and Met deficiency diet (Met- group, Met 0.27%). Each group included six replicates with 30 chicks per replicate. The trial lasted 6 weeks (0–6 weeks), both groups were fed the same basal diet which met the needs of Met during the observation period (7–24 weeks). Results showed that Met deficiency significantly decreased (P < 0.05) body weight (BW), average daily weight gain (ADG), average daily feed intake (ADFI) and tibia length (TL) compared to the NC group during the trial period (0–6 weeks). Also, Met deficiency dramatically increased (P < 0.05) feed conversion ratio (FCR) during the trial and observation period (7–24 weeks). In addition, during the observation period, the BW and ADG were decreased (P < 0.05) in the Met- group. Moreover, Met- group decreased (P < 0.05) villi height and villi height/crypt depth ratio in jejunum at 6th weeks. In addition, the concentrations of serum main free amino acids (FAA) in the Met- group were significantly increased (P < 0.05) at 6th weeks, while were decreased at 16th weeks. Based on the α-diversity and PCoA analysis in β-diversity, there were no significant differences in the cecal microbial composition between NC and Met- groups. However, the LEfSe analysis revealed that differential genera were enriched in the NC or Met- groups. The Haugh unit, shell thickness and egg production in the Met- group were significantly lower (P < 0.05) than in the NC group. In conclusion, these results revealed that dietary supplementation of appropriate Met could substantially improve the growth performance, host amino acid metabolism and intestinal development and continuously improve the laying performance and thus boost the health of growing hens.

Effects of in ovo feeding of disaccharide and/or methionine on hatchability, growth performance, blood hematology, and serum antioxidant parameters in geese

A completely randomized design employing a 2 × 2 factorial experiment was designed in this study to evaluate the effects of in ovo injection of disaccharide (DS) and/or methionine (Met) on hatchability, growth performance, blood hematology, and serum antioxidant parameters in geese. A total of 600 fertilized geese's eggs containing live embryo were randomly assigned into 4 groups with 6 replicates and 25 eggs per replicate. Factors in four groups comprised noninjection, DS injection (25 g/L maltose + 25 g/L sucrose + 7.5 g/L NaCl), Met injection (5 g/L Met + 7.5 g/L NaCl), or DS plus Met injection (25 g/L maltose + 25 g/L sucrose + 5 g/L Met + 7.5 g/L NaCl), respectively. We found that the administration of DS in embryo increased hatching time, yolk sac-free carcass weight, yolk sac-free carcass indexes and decreased assisted hatching ratio, yolk sac weight, yolk sac indexes, but did not affect hatchability and mortality. Moreover, higher body weight and serum glucose concentrations in DS injection group compared with noninjection group were observed on day of hatching. The body weight and average daily gain (ADG) of geese in DS injection group were higher than noninjection group after incubation. In ovo injection of Met increased hatching time and yolk sac-free carcass indexes, but decreased yolk sac indexes. In addition, the strategy of in ovo feeding of Met led to higher body weight, ADG, serum uric acid, glutathione (GSH), and glutathione peroxidase concentrations, as well as lower GSSG/GSH ratio, serum glutathione disulfide (GSSG), and malondialdehyde (MDA) concentrations than the noninjection group on day of hatching. The post-hatching body weight, ADG, serum total protein, albumin, and uric acid concentrations increased, whereas post-hatching serum GSSG and MDA concentrations and GSSG/GSH ratio decreased when injected with Met. In addition, synergistic effects of in ovo injection of DS plus Met on hatching time as well as post-hatching body weight and ADG were observed. Therefore, in ovo injection of DS plus Met was demonstrated to be a way to improve the development of geese during early incubation stages.

Prolonged scotophase within a 24 hour light regime improves eggshell quality by enhancing calcium deposition in laying hens

Calcium (Ca) and phosphorus (P) transporters are responsible for their absorption and transport in small intestine and kidney, contributing to eggshell formation. The light-dark cycle is a primary cue in the reproduction of laying hen. In this study, we investigated the effect of different light-dark programs on eggshell quality and the expression of genes related to Ca and P transportation in laying hens. Seventy-two 56-week-old laying hens were randomly divided into two groups and reared at 16-h light and 8-h dark (control) or 9-h light and 15-h dark regime (long dark phase, LDP). The expressions of calcium transporter calbindin-D28k (CaBP-D28k), plasma membrane Ca ATPase 1b (PMCA1b), and phosphorus transporter NaPi-IIb (NPt2b) and NaPi-IIa (NPt2a) were measured in the small intestine, kidney, and eggshell gland. The results showed that feed intake (P < 0.001) and egg weight (P = 0.05) were decreased by LDP treatment. Compared with control, the eggshell hardness was increased (P = 0.011) by LDP treatment, but the eggshell thickness and the percentage of eggshell were not changed. The Ca and P contents in eggshell were increased by LDP treatment. During the scotophase, LDP-hens showed higher serum Ca (P = 0.0056) and P levels (P = 0.079) but lower alkaline phosphatase (ALP) activity than that of control hens. In the duodenum, the relative higher expression of CaBP-D28k and PMCA1b in scotophase compared to photophase was masked by LDP treatment. The expression of CaBP-D28k and osteopontin (OPN) in the eggshell gland were increased by LDP treatment, compared to control hens. In the jejunum, the protein expression levels of CaBP-D28k and PMCA1b decreased during photophase in LDP-hens. The result indicates that the increased blood Ca and P concentration during scotophase by LPD treatment is beneficial to the deposition of Ca and P in the eggshell. The result offers an alternative strategy for managing laying hens with poor eggshell quality.