Rumen-protected methionine a feed supplement to low dietary protein: effects on microbial population, gases production and fermentation characteristics

Abstract

The present study was performed to evaluate the effects of different concentration of rumen-protected methionine (RPMet) with a low level of crude protein (CP) using rumen simulation technology on many parameters. The experiment was assigned randomly into four treatments: (1) high protein diet (163.39 g/kg CP) without RPMet (HP); (2) low protein diet (146.33 g/kg CP) without RPMet (LP); (3) low protein diet, supplement with low RPMet (RPMet: 0.11 g/kg) (LPLMet); and (4) low protein diet, supplement with high RPMet (RPMet: 0.81 g/kg) (LPHMet), mixed with 20 g basal diet in each fermenter. Based on National Research Council (NRC) (Nutrient requirements of dairy cattle, National Academies Press, Washington, DC, 2001 ) recommendation for dairy ruminants HP diet was formulated as positive normal control and LP as a negative control. Results demonstrated that CP disappearance was found significantly higher (P < 0.05) in supplement groups compared with HP and found similar (P > 0.05) with LP. However, neutral detergent fiber (NDF) and gross energy (GE) were found a parallel among supplement groups compared to HP and higher than LP. Furthermore, microbial crude protein, total and short chain fatty acids were found similar in LPHMet and HP and found significantly higher than LPLMet and LP. The R. albus population of LPHMet found parallel to HP and pointedly higher than LP in a solid and liquid fraction. Daily production of ammonia nitrogen, total gas, and methane were higher in HP than LP, LPLMet, and LPHMet. Overall, results concluded that values of digestibility, rumen fermentation, microbial crude protein, and R. albus population were similar of LPHMet to that of HP group. However, production of ammonia-N, total gas, and methane volume were significantly higher in the HP group than LPLMet, LPHMet, and LP groups. In conclusion, rumen-protected methionine is a good feed supplement to low dietary protein in the level of 0.81 g/kg.

Effects of Supplementing Rumen-Protected Methionine on Production Performance, Apparent Digestibility, Blood Parameters, Ruminal Metabolites and Economic Effectiveness in Lactating Holstein Dairy Cows

“…Although no effects were found in VFA concentration during the whole period, cows fed RPM had higher ruminal butyrate and isovalerate contents at 2h after feeding, which is consistent with other studies [13,48]. A previous research described that ruminal VFA production depended on substrates, bacterial populations and ber degradation [49].…”

“…A previous research described that ruminal VFA production depended on substrates, bacterial populations and ber degradation [49]. Some researchers noted that bacterial populations changed in fermenter uid if rumen inoculum accepted different dietary CP with or without RPM in vitro, and abundance of Ruminococcus albus was the highest as dietary low protein with high RPM level [13]. In addition, another study started the diets which had well-balanced essential AA pro les especially RPM evaluated the abundance of ruminal brinolytic bacterial (R. avefaciens, F. succinogenes, and R. albus) [50].…”

“…Recently research has shown that an increase in overall dry matter intake (DMI) could be found after parturition when cows fed lower dietary CP and RPM [11]. In addition, supplementing RPM may allow lower CP diets to improve N e ciency and reduce urinary N excretion [8,12] and production of total gas and methane volume [13]. Meanwhile, a previous meta-analysis of dietary protein content noted that not overfeeding dietary CP is the most e cient means to increase e ciency of N utilization [14].…”

Nutrient Digestibility, Microbial Fermentation, and Response in Bacterial Composition to Methionine Dipeptide: An In Vitro Study

“…In a recent study, soybean oil-induced milk fat depression was associated with significant alterations in the ruminal microbiota, which could be mitigated by rumen-protected Met [ 13 ]. Furthermore, Met expanded the proportion of cellulolytic bacteria ( Ruminococcus albus ) and increased microbial protein, and volatile fatty acid synthesis in an in vivo study [ 16 ]. Hence, Met could interact with bacteria and ultimately support better fermentation in the rumen [ 13 , 16 ].…”

Study of the Growth and Carcass Composition of Awassi Lambs Fed With Adding Protected Methionine

“…Most protein intake is digested in the rumen to produce amino acids as an intermediate compounds which then are used either to synthesis microbial protein or will be transformed into a ketone acids and ammonia, theses end products are then enters into a different metabolic pathways (Zadeh et al, 2013), this may reduce the efficiency utilization of the essential amino acids (Abbasi et al, 2019), and animal performance (Hasan and Hasan, 2009) due that it is advised in modern feeding programs to use an abundant amount of ruminal digestive protein which shall result in using much more amino acids in synthesis microbial protein, excess amino acids in this feed program will be absorbed by the small intestine to provide more amounts of essential amino acids which play a major role in the productive and physiological performance during specific periods (Kaufman et al, 2018;Savari et al, 2018). Methionine is considered one of most important essential amino acids, due to its great role in the metabolic pathways, such as play as a donor of methyl group, starting point in the formation and building of protein within the living cells and the metabolism of fat in the liver (Sun et al, 2016, Wingfield, 2018, most of feedstuffs used in animal feeding like barley, yellow corn and soybean meal are low in their content of methionine (NRC, 2001), methionine percentage in the microbial protein formed in the rumen is 2% which is a little higher than its percentage in the body tissue which is estimated to be 1.8 % (MacRae et al, 1993).…”