Measurement in vivo of rumen microbial protein synthesis

1975 ◽  
Vol 26 (4) ◽  
pp. 689 ◽  
Author(s):  
DJ Walker ◽  
CJ Nader

A method is described for the measurement in vivo of ruminal microbial protein synthesis. The method depends upon the incorporation into microbial protein of sulphur derived from 35S -labelled inorganic sulphate infused continuously into the rumen. Steady-state labelling of rumen digesta protein and specific activity of microbial sulphur are used, along with estimates of total digesta mass, to calculate total microbial sulphur in the rumen. The rate of disappearance of isotope from the rumen after cessation of [35S]sulphate infusion is used to calculate the flow rate of microbial s~dphur from that organ. Microbial sulphur may be used to estimate microbial nitrogen or crude protein by means of conversion factors.

2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4413
Author(s):  
Luis Gabriel Alves Cirne ◽  
Américo Garcia da Silva Sobrinho ◽  
Fernanda Carvalho Basso ◽  
Roque Takahashi ◽  
Thiago Henrique Borghi ◽  
...  

<p>The objective of this study was to evaluate intake, microbial protein synthesis, and nitrogen balance in lambs fed diets containing 0.00, 12.50, and 25.00% mulberry hay substituting the concentrate. Twentyfour Ile de France lambs at approximately 60 days of age, with a body weight of 15.48 ± 0.07 kg, were confined in individual stalls and slaughtered upon reaching 32 kg body weight. Only the intakes of ether extract and metabolizable energy decreased linearly (P&lt;0.05) as the participation of mulberry hay in the concentrate was increased. Nitrogen in the feces, expressed in g day–1 and g kg0.75 day–1, increased linearly (P&lt;0.05), whereas excretions (mmol day–1) of allantoin, total purines, and absorbed microbial purines, microbial production (g day–1) expressed in microbial nitrogen and microbial crude protein, and microbial efficiency expressed in g MN kg–1 RDOM–1 and g MP kg–1 of TDN decreased linearly as the level of hay in the diet was increased. Mulberry hay substituting the concentrate in diets for feedlot lambs reduces the microbial protein synthesis.</p>


1998 ◽  
Vol 22 ◽  
pp. 306-308
Author(s):  
M. D. Carro ◽  
E. L. Miller

The estimation of rumen microbial protein synthesis is one of the main points in the nitrogen (N)-rationing systems for ruminants, as microbial protein provides proportionately 0.4 to 0.9 of amino acids entering the small intestine in ruminants receiving conventional diets (Russell et al., 1992). Methods of estimating microbial protein synthesis rely on marker techniques in which a particular microbial constituent is related to the microbial N content. Marker : N values have generally been established in mixed bacteria isolated from the liquid fraction of rumen digesta and it has been assumed that the same relationship holds in the total population leaving the rumen (Merry and McAllan, 1983). However, several studies have demonstrated differences in composition between solid-associated (SAB) and fluid-associated bacteria in vivo (Legay-Carmier and Bauchart, 1989) and in vitro (Molina Alcaide et al, 1996), as well in marker : N values (Pérez et al., 1996). This problem could be more pronounced in the in vitro semi-continuous culture system RUSITEC, in which there are three well defined components (a free liquid phase, a liquid phase associated with the solid phase and a solid phase), each one having associated microbial populations.The objective of this experiment was to investigate the effect of using different bacterial isolates (BI) on the estimation of microbial production of four different diets in RUSITEC (Czerkawski and Breckenridge, 1977), using (15NH4)2 SO4 as microbial marker, and to assess what effects any differences would have on the comparison of microbial protein synthesis between diets.This study was conducted in conjunction with an in vitro experiment described by Carro and Miller (1997). Two 14-day incubation trials were carried out with the rumen simulation technique RUSITEC (Czerkawski and Breckenridge, 1977). The general incubation procedure was the one described by Czerkawski and Breckenridge (1977) and more details about the procedures of this experiment are given elsewhere (Carro and Miller, 1997).


2015 ◽  
Vol 15 (2) ◽  
pp. 289-305 ◽  
Author(s):  
Maja Fijałkowska ◽  
Barbara Pysera ◽  
Krzysztof Lipiński ◽  
Danuta Strusińska

Abstract Losses of crude protein during ensiling of herbages, in contrast to carbohydrates, do not affect the reduction of its content; their form is changed into greater solubility non-protein compounds and also highly degraded forms, which lower the efficiency of the microbial protein synthesis in the rumen. These processes are accompanied by a change of amino acid composition of herbage protein and decrease in intestinal digestibility of protein from feeds as a result of the formation of indigestible complexes with carbohydrates (ADIN). Reduction of protein degradation in silages is achieved by accelerated acidity through addition of acids or dominance of homofermentative bacteria. The positive effects of fermentation inhibitors or sorbents use, as well as the wilting of raw material on the level and rate of protein degradation were demonstrated by many researchers. A greater contribution of protein nitrogen and reduction of deamination in silages can also be obtained by using bacteria inoculants. Increasing the proportion of protein nitrogen is accompanied by the improved efficiency of microbial protein synthesis.


2016 ◽  
Vol 154 (6) ◽  
pp. 1102-1109 ◽  
Author(s):  
E. DE JESUS DOS SANTOS ◽  
M. L. ALBUQUERQUE PEREIRA ◽  
M. PEREIRA DE FIGUEIREDO ◽  
H. G. DE OLIVEIRA SILVA ◽  
J. FERREIRA DA CRUZ ◽  
...  

SUMMARYThe experiment, conducted at Bahia, Brazil, from May to August 2010, aimed to evaluate the nitrogen (N) balance, urea excretion and microbial protein synthesis in lactating goats fed pelleted concentrates with the addition of crude protein (CP), obtained by replacing alfalfa hay with soybean meal. The diets consisted of different levels of CP and 200 g of roughage (Tifton 85 hay)/kg. Maize and mesquite bran were used as the energy source, with maize replaced by mesquite bran in the ratio of 1·7:1. Eight female Saanen goats were used, confined in individual pens and allocated to a 4 × 4 Latin square design. The N balance in the body was positive, and loss of body weight (–0·03 g/day) was observed for the diet with 190 g CP/kg. The concentration (mg/dl) of urea in urine, milk and blood plasma was positively influenced in a linear form, and the highest rate of increase was found in urine, with 2 mg/dl for every 10 g CP/kg added to the diet. The microbial protein synthesis was not affected, but the diets reduced the microbial protein (44 g/day) and its ruminal production efficiency (30 g/kg total digestible nutrients). The levels above 190 g of CP are not recommended because of the energy expenditure required to excrete the urea.


Author(s):  
L.A. Sinclair ◽  
P.C. Garnsworthy ◽  
P.J. Buttery

Recently methods based upon the HPLC separation and detection of cytosine (Koenig 1980) and the spectrophotometric analysis of the total purine content of microbes (Zinn and Owens 1986) have been proposed to estimate microbial nitrogen flow at the duodenum. Little work has been undertaken in-vivo to evaluate cytosine as a marker and to compare it with current techniques. The present trial was designed to evaluate this marker and to compare it with diaminopimelic acid (DAPA), [3H]leucine and the total purine technique. In addition, recent reports (Hvelpund and Madsen 1985) have indicated that expressing miaobial efficiency in terms of carbohdrate, as opposed to organic matter degraded in the rumen, reduced the variation in microbial yield. This was also investigated.


2017 ◽  
Vol 9 (7) ◽  
pp. 164 ◽  
Author(s):  
Renato Tonhá Alves Júnior ◽  
Evaristo Jorge Oliveira de Souza ◽  
Airon Aparecido Silva de Melo ◽  
Dulciene Karla De Andrade Silva ◽  
Thaysa Rodrigues Torres ◽  
...  

Four concentrations (0, 200, 400, 600 and 800 mg extract per ml of water) of mesquite extract were used as phytogenic additive to verify the potential to increase the nutritional value of the feed, ruminal parameters (primarily propionate production) and nitrogen use efficiency, microbial protein synthesis and quantify the reduction of ciliated protozoa and characterize the ingestive behavior of sheep. Ten adult male sheep were subjected to a 5 × 5 double Latin square design. Prior to feeding, the animals received the mesquite extract. Nutrient intake was estimated from the difference of the amount of feed provided and the total surplus. Rumen content samples were collected to evaluate the profile of short-chain fatty acids, ammonia nitrogen, pH, ciliated protozoa, turnover rate and disappearance rate. To estimate the microbial protein synthesis, the technique of purine derivatives was used. The mesquite extract quadratically increased (P < 0.05) the digestibility of dry matter, organic matter, crude protein and total digestible nutrients, as well as increased propionate production, acetate:propionate ratio and microbial protein synthesis. The numbers of ciliate protozoa in the rumen decreased as a result of mesquite extract inclusion in the diet. The use of mesquite pod extract at a concentration of 488 mg/mL is recommended to improve digestibility of dry matter, organic matter, crude protein and total digestible nutrients, and to optimize microbial protein synthesis and increase propionic acid production.


2018 ◽  
Vol 19 (2) ◽  
pp. 178-192
Author(s):  
Fabiola Espindola Ortega de Lima ◽  
Rafael Henrique de Tonissi e Buschinelli de Goes ◽  
Jefferson Rodrigues Gandra ◽  
Diego dos Santos Penha ◽  
Raquel Tenório de Oliveira ◽  
...  

SUMMARY This study analyzed the effect of including copaiba oil as an additive for cattle supplemented on pasture, during the dry season. Four crossbred steers, castrated, with 245 ± 25 kg, aged about 18 months, fitted with permanent rumen cannula; were randomly assigned to a 4×4 Latin square. All animals were housed in individual paddocks (0.3 ha), uniformly covered with Brachiaria brizantha cv Marandu, with through and drinking fountain; and were given a concentrate at 500g/100 kg BW containing 380 g/kg crude protein (%DM). The copaiba oil was added to the supplement as a spray, in the proportions of 0, 0.5; 1.0 and 1.5 g/kg DM intake. Spraying supplementation was performed daily at the time of supply of the supplement. Data of intake and digestibility of nutrients, ruminal pH; ruminal ammonia nitrogen, and microbial protein synthesis were tested by analysis of variance and polynomial regression, adopting a significance level of 5%. The inclusion of copaiba oil quadratically affected total dry matter intake (P=0.030) and CP digestibility (P=0.043), without altering ruminal metabolism (P>0.05) and microbial protein synthesis (P>0.05) of the animals kept on pasture.


2020 ◽  
Vol 4 (2) ◽  
pp. 839-847
Author(s):  
Daryoush Alipour ◽  
Atef Mohamed Saleem ◽  
Haley Sanderson ◽  
Tassilo Brand ◽  
Laize V Santos ◽  
...  

Abstract This study evaluated the effect of combinations of feed-grade urea and slow-release urea (SRU) on fermentation and microbial protein synthesis within two artificial rumens (Rusitec) fed a finishing concentrate diet. The experiment was a completely randomized, dose–response design with SRU substituted at levels of 0% (control), 0.5%, 1%, or 1.75% of dry matter (DM) in place of feed-grade urea, with four replicate fermenters per dosage. The diet consisted of 90% concentrate and 10% forage (DM basis). The experiment was conducted over 15 d, with 8 d of adaptation and 7 d of sampling. Dry matter and organic matter disappearances were determined after 48 h of incubation from day 9 to 12, and daily ammonia (NH3) and volatile fatty acid (VFA) production were measured from day 9 to 12. Microbial protein synthesis was determined on days 13–15. Increasing the level of SRU quadratically affected total VFA (Q, P = 0.031) and ammonia (Q, P = 0.034), with a linear increment in acetate (L, P = 0.01) and isovalerate (L, P = 0.05) and reduction in butyrate (L, P = 0.05). Disappearance of neutral detergent fiber (NDF) and acid detergent fiber (ADF) was quadratically affected by levels of SRU, plateauing at 1% SRU. Inclusion of 1% SRU resulted in the highest amount of microbial nitrogen associated with feed particles (Q, P = 0.037). Responses in the efficiency of microbial protein synthesis fluctuated (L, P = 0.002; Q, P = 0.001) and were the highest for 1% SRU. In general, the result of this study showed that 1% SRU in combination with 0.6% urea increased NDF and ADF digestibility and total volatile fatty acid (TVFA) production.


2017 ◽  
Vol 57 (8) ◽  
pp. 1702 ◽  
Author(s):  
M. K. Bowen ◽  
D. P. Poppi ◽  
S. R. McLennan

The efficiency of microbial protein synthesis (EMPS) in cattle grazing a range of tropical pasture types was examined using a new method of intra-jugular infusion of chromium–EDTA to estimate urinary excretion of purine derivatives. Seven pasture types were studied in south-eastern Queensland, Australia, over a 13-month period. These included native tropical grass (C4) pasture (major species Heteropogon contortus and Bothriochloa bladhii) studied in the early wet, the wet–dry transition and the dry season; introduced tropical grass (C4) pasture (Bothriochloa insculpta) in the mid-wet season; two introduced tropical legume species (C3; Lablab purpureus and Clitoria ternatea); and the temperate-grass (C3) pasture, ryegrass (Lolium multiflorum). There was a large range in EMPS across pasture types, with a range of 26–209 g microbial crude protein per kilogram digestible organic matter intake (DOMI). Estimated rumen-degradable protein (RDP) supply (42–525 g/kg DOMI) was the major factor associated with EMPS across the range of pasture types studied. EMPS in steers grazing all tropical grass pastures was low (&lt;130 g/kg DOMI) and limited by RDP supply. Negative linear relationships (P &lt; 0.05) between EMPS and concentrations of both neutral detergent fibre and acid detergent fibre in extrusa were evident. However, non-fibre carbohydrate in extrusa, total non-structural carbohydrate concentration in plucked pasture leaf, rumen fluid and particle dilution rate, protozoal concentration in rumen fluid and rumen fluid pH were not correlated with EMPS. It was concluded that EMPS was well below 130 g microbial crude protein per kilogram DOMI when cattle grazed unfertilised, tropical grass pastures in south-eastern Queensland and that RDP was the primary limiting nutrient. High EMPS was associated with a very high RDP, vastly in excess of RDP requirements by microbes.


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