Effect of Methionine Supplementation on Serum Metabolism and the Rumen Bacterial Community of Sika Deer (Cervus nippon)

Abstract

Methionine is the first or second limiting amino acid for ruminants, such as sika deer, and has a variety of biological functions such as antioxidant activity, immune response, and protein synthesis. This study aimed to investigate the effects of methionine supplementation on antler growth, serum biochemistry, rumen fermentation, and the bacterial community of sika deer during the antler-growing period. Twelve 4-year-old male sika deer were randomly assigned to three dietary groups supplemented with 0 g/day (n = 4, CON), 4.0 g/day (n = 4, LMet), and 6.0 g/day (n = 4, HMet) methionine. No significant difference (p > 0.05) was found in the production performance between the three groups, but antler weight was higher in both the LMet and HMet groups than in the CON group. Methionine supplementation significantly increased the serum glutathione peroxidase activity (p < 0.05). The serum immunoglobulin G level was significantly higher in the HMet group than in the other two groups (p < 0.05). No significant effect was found on the apparent amino acid digestibility of the three groups, but cysteine and methionine digestibility were higher in the LMet group. The serum hydroxylysine level was significantly lower in the LMet and HMet groups, whereas the serum lysine level was significantly lower in the HMet group compared with the CON group (p < 0.05). The LMet group had the highest but a nonsignificant total volatile fatty acid content and significantly higher microbial protein content in the rumen than the CON group (p < 0.05). The phyla Bacteroidetes, Firmicutes, and Proteobacteria were dominant in the rumen of the sika deer. The principal coordinate analysis (PCoA) and analysis of similarities (ANOSIM) results showed a significant change in the bacterial composition of the three groups (p < 0.05). The relative abundance of Prevotella and Rikenellaceae-RC9 was significantly higher in the LMet group compared with the CON group and CON and HMet groups, respectively. These results revealed that methionine supplementation improved the antioxidant activity and immune status, affecting amino acid metabolism and rumen microbial composition of the sika deer.

Methionine Supplementation Affects Fecal Bacterial Community and Production Performance in Sika Deer (Cervus nippon)

“…The apparent digestibility of organic matter, NDF and ADF increased significantly in the LMet group under the experimental conditions, which was consistent with previous predictions for changes in nutrient utilization. A previous study found changes in the abundance of a variety of rumen bacteria associated with cellulose degradation, especially in the LMet group, which showed a significant increase, improving the animal’s ability to utilize crude fiber components in the feed [ 15 ]. It has also been shown that methionine supplementation had a positive effect on the fermentation rate of NDF in the rumen of heifers, which facilitated the utilization of cellulose by the animals [ 24 ].…”

“…The experiment was preceded by a one-week pre-experiment and consisted of a four-week dietary treatment in June 2021. The deer in each group were fed a corn silage and concentrate based diet with a dry matter content of 35% to 65% [ 15 ]. Methionine was randomly added to the basal diet at 0 g/day (CON), 4 g/day (LMet) or 6 g/day (HMet).…”

Effect of Methionine Hydroxy Analog on Hu Sheep Digestibility, Rumen Fermentation, and Rumen Microbial Community In Vitro

“…At the genus level, Prevotella taxa were more abundant in the HMBi and MHA-Ca groups than in the Control group. Prevotella has been reported to be primarily involved in the degradation of proteins and carbohydrates [ 57 ]. It was found that Prevotella_1 was significantly positively correlated with DMD, MCP, and fermentation parameters.…”

Bioactive Compounds, Amino Acids, Fatty Acids, and Prebiotics in the Seed of Mahuad (Lepisanthes rubiginosa (Roxb.) Leenh)

“…Proline is involved in numerous biological processes, including protein and amino acid synthesis, structure, nutrition, and immune response [39]. Methionine, on the other hand, plays important roles in metabolism, the immune system, antioxidant, and digestive function [40,41]. Cereals and legumes serve as primary food and feed sources for both humans and animals; however, they often lack adequate levels of certain essential amino acids, especially methionine and lysine [42].…”

“…In poultry diets, methionine stands out as an essential amino acid and is typically the first limiting amino acid [43][44][45]. This sulfur-containing amino acid is also a limiting amino acid in other animal feeds including fish and deer [41,46]. Arginine participates in diverse biological activities, such as protein synthesis, immune response, and nitric oxide production [47].…”