Effects of Different Methionine Levels in Low Protein Diets on Production Performance, Reproductive System, Metabolism, and Gut Microbiota in Laying Hens

Abstract

This study investigated the effects of different levels of methionine (Met) in a low protein diet on the production performance, reproductive system, metabolism, and gut microbial composition of laying hens to reveal the underlying molecular mechanism of Met in a low protein diet on the host metabolism and gut microbial composition and function of hens. A total of 360 healthy 38-week-old Peking Pink laying hens with similar body conditions and egg production (EP) were randomly divided into four groups with nine replicates per treatment and 10 hens per replicate. The hens in each treatment group were fed low protein diets containing different levels of Met (0.25, 0.31, 0.38, and 0.47%, respectively) for 12 weeks. Feed and water were provided ad libitum throughout the trial period. The results showed that, compared with the 0.25% Met group, the final body weight (FBW), average daily gain (ADG), EP, egg weight (EW), and average daily feed intake (ADFI) in the other groups were significantly increased and feed egg ratio (FER) was decreased. Meanwhile, the EW and yield of abdominal fat (AFY) in the 0.47% Met group were higher than those in other groups. The triglyceride (TG), estradiol (E2), total protein (TP), albumin (ALB), and immunoglobulin A (IgA) in the 0.38 and 0.47% Met groups were higher than those in other groups. In addition, 16S rRNA gene sequencing revealed that there was no difference in the Sobs index, ACE index, and Shannon index among all groups. However, it is worth noting that feeding low protein diets with Met changed the gut microbial composition (e.g., the supplementation of Met increased the level of Lactobacillus and decreased the proportion of Faecalibacterium). Also, our results showed that the changes in gut microbial composition induced by the diets with different levels of Met were closely related to the changes of key parameters: ADFI, EW, FBW, TG, EM, EP, ADG, FER, and uric acid (UA). Our results highlight the role of adding an appropriate amount of Met to the low protein diet in laying hens, which could improve the gut microbial composition, production performance, reproductive system, and nutrient metabolism of laying hens. In conclusion, this study suggested that when the Met level was 0.38%, the production performance of the laying hens was pretty good.

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

“…Notably, Dai et al discovered that AA could regulate the composition of the intestinal bacterial population from the small intestine in pigs ( 43 ). In this study, we found that there were no significant differences in alpha diversity indices between NC (Met 0.46%) and Met- group (Met 0.26%), which was similar to the previous study ( 44 ). Wu et al found that D-methionine supplementation had no effects on alpha diversity indices in male Wistar rats (176–200 g, 6 weeks old), who uncovered the Met diet does not alter gut microbiota structure ( 45 ).…”

Growth Performance, Bone Development and Phosphorus Metabolism in Chicks Fed Diets Supplemented with Phytase Are Associated with Alterations in Gut Microbiota

“…The methods used for intestinal microbiome analysis were consistent with a previous paper [ 21 ]. Alpha-diversity measure was analyzed using MOTHUR software (1.30.2).…”

Effects of dietary methionine supplementation on the growth performance, immune responses, antioxidant capacity, and subsequent development of layer chicks

“…Dietary amino acid deficiencies negatively affect egg production, egg quality, and serum biochemical indices ( Geng et al, 2021 ), and a deficiency of Met affects protein synthesis ( Elango, 2020a ; Liu et al, 2022 ; Teng et al, 2023 ). When animals are healthy, protein synthesis increases, and the serum TP and ALB concentrations also tend to increase ( Ma et al, 2021 ). UA is an end product of catabolism ( Chen et al, 2018 ), and the serum UA concentration reflects the health status of the animal.…”

“…UA is an end product of catabolism ( Chen et al, 2018 ), and the serum UA concentration reflects the health status of the animal. Ma et al showed that high dietary Met levels (0.31–0.47%) are associated with greater amino acid utilization and alterations in the serum UA concentration ( Ma et al, 2021 ). As the dietary level of methionine (Met) increased, corresponding increases in the serum concentrations/activities of TP, ALB, and ALP were observed.…”

“…A lack of Met in the diet affects immunity ( Wu et al, 2013 ; Bian et al, 2020 ). For example, Ma et al showed that hens fed a relatively large amount of Met were metabolically active and showed superior immune responses ( Ma et al, 2021 ). Immunoglobulins play an important role in humoral immunity ( Ulmer-Franco et al, 2012 ; Megha and Mohanan, 2021 ), and in the present study, Met supplementation increased the serum concentrations of the anti-inflammatory cytokine IL-10, as well as those of IgA and IgM in 14-day-old chicks, which suggests that Met may have a positive effect on their immune status.…”