Background: The high content of fiber and macromolecular substances in mushroom residue limits its utilization potential. After we fermented seafood mushroom residue with microorganisms, we found that its palatability and utilization have been greatly improved.The purpose of this study was to investigate the effects of feed containing fermented seafood mushroom residue on the growth performance and rumen microorganisms of goats. Methods: Forty-eight Jianyang big-ear goats with similar weight and good health were selected and randomly divided into 4 groups with 12 goats in each group. The control group (C) was fed a basic diet, and the experimental group 1 (L), 2 (M), and 3 (H) were fed diets supplemented with 20%, 30% and 40% fermented seafood mushroom residue.Results: Incorporating 20% fermented mushroom residue significantly increased the average daily gain (ADG) and average daily feed intake (ADFI) and reduced feed to gain ratio (F/G). Incorporating 30% in the diet significantly increased both ADFI and F/G. Growth performance was reduced when greater than 30% fermented mushroom residue was added. The beta diversity of the rumen flora was significantly increased with the 20% fermented mushroom residue diet. The relative abundance of Veillonellaceae, Ruminococcaceae, and Prevotellaceae increased, and the KEGG pathways related to metabolism of cofactors and vitamins, lipid metabolism, and xenobiotics biodegradation and metabolism were enhanced. Forty-nine KEGG pathways significantly associated with ADG were identified. Twenty-six pathways, including protein kinases, mineral absorption, propanoate metabolism, and biosynthesis of unsaturated fatty acids, were positively correlated with ADG. The remaining pathways, including pathogenic Escherichia coli infection, phenylpropanoid biosynthesis, shigellosis, and cyanoamino acid metabolism, were negatively correlated with ADG.Conclusions: These results show that adding 20% fermented seafood mushroom residue can improve the growth performance of goats and have a positive effect on goat rumen microorganisms.

Background: Because of disadvantages of excessive dietary crude protein (CP), decreasing dietary CP of dairy cows has attracted the worldwide attention. Rumen protected methionine (RPM) supplementation can allow lower CP diets and is beneficial to milk production performance, N efficiency of cows and environment. The aim of this study was to evaluate the effects of reducing dietary CP and supplementing RPM on production, digestibility of nutrients, blood parameters, ruminal metabolites and economic effectiveness in lactating Holstein dairy cows. Results: A total of 96 lactating cows (63 ± 25 d in milk; 34.4 ± 5.74 kg/d of milk production; mean ± SD) were randomly assigned to 1 of 2 treatments: diet containing 17.3% CP without RPM (control group; CON; n = 49); diet containing 16.4% CP with supplementing 15.0 g/d of RPM (treatment group; RPM; n = 47). No effect was observed of reducing dietary CP on milk yield and milk composition. The apparent digestibility of nutrients was similar between treatments. The results related to blood showed that cows in RPM group exhibited lower concentration of blood urea nitrogen than that in CON group (P < 0.001). Moreover, there were no differences between treatments on concentrations of aspartate transaminase, alanine transaminase, alkaline phosphatase, globulin and albumin. In ruminal metabolites, microbial crude protein (MCP) of dairy cows in RPM group was higher compared with CON group (P = 0.006). Ruminal volatile fatty acid (VFA) contents were not changed by treatments except that the concentrations of butyrate and isovalerate of RPM group were higher than that of CON group at 2 h after feeding (P < 0.05). In addition, supplying the diet of 16.4% CP with RPM supplementation to cows could reduce feeding cost by 0.5 $/d per cow and boost net profits. Conclusions: Lower dietary CP with RPM supplementation did not limit milk yield, milk composition and apparent digestibility of nutrients, and could improve nitrogen utilization of dairy cows and synthesis of MCP in rumen, change VFA production at 2 h after feeding, as well as boost the economic benefits of the dairy farms.