Studies on the Nutrition of Macropodine Marsupials. 5.microbial Fermentation in the Forestomach of Thylogale Thetis and Macropus Eugenii.

1983 ◽  
Vol 31 (4) ◽  
pp. 433 ◽  
Author(s):  
DW Dellow ◽  
JV Nolan ◽  
ID Hume

Rates of volatile fatty acid (VFA) and ammonia production at different sites along the forestomach of Thylogale thetis, the red-necked pademelon, and Macropus eugenii, the tammar wallaby, were estimated in vitro and in vivo. Estimates of the flow of microbial nitrogen from the stomach were also obtained in vivo. In both species VFA production was faster in vitro and in vivo in the sacciform forestomach than in the tubiform forestomach. The ratio of total VFA production to digestible organic matter (OM) intake was similar in the 2 species, and similar to published estimates for ruminants. Net production of ammonia in vivo was faster in the sacciform forestomach than in the tubiform forestomach of T. thetis but not of M. eugenii. The ratio of total net ammonia production to nitrogen intake was similar in the 2 species, and net synthesis of microbial protein per kilogram OM apparently fermented in the stomach of T. thetis and M. eugenii was similar to that in ruminants. The decrease in fermentation rate along the forestomach of both species was consistent with the previously reported pattern of apparent digestion of OM in the macropodine stomach. Although this pattern of microbial activity differs from that in ruminants, the overall fermentation is extensive. Thus the lower fibre digestibility often found in macropodines compared with sheep may be related to a faster rate of passage of particulate digesta through the macropodine forestomach, but it is not due to a less efficient microbial fermentation.

1992 ◽  
Vol 4 (5) ◽  
pp. 533 ◽  
Author(s):  
G Chaturapanich ◽  
RC Jones ◽  
J Clulow

The objectives were to assess the following in a marsupial: which proteins are synthesized by the different regions of the epididymis and secreted into the lumen of the ductus; the effect of the experimental method on the detection of protein secretion; the role of the testis in regulating the protein synthesis and secretion; and whether any of the secreted proteins may associate with spermatozoa. Samples from untreated animals were collected for examination by perfusing Krebs-bicarbonate through the ductus epididymidis in vivo (microperfusion), and after incorporation of [35S]methionine during incubation of minced duct in vitro. Electrophoresis of the samples showed that the caput and corpus epididymidis (initial segments) secreted most of the proteins that were synthesized and secreted by the epididymal mucosa, and that the cauda epididymidis secreted mainly blood proteins. Also, many more proteins were secreted in vitro than into the microperfusates in vivo, or were found by Jones (1987) in micropuncture samples of epididymal plasma. The synthesis and secretion of five proteins was androgen dependent (M(r) 75,700, 30,000, 18,700, 17,400 and 12,800). Also, the luminal fluids from the testis stimulated the secretion of two proteins (M(r) 46,300 and 36,100) and inhibited the secretion of three proteins (M(r) 43,000, 32,300 and 21,400). Examination of detergent extracts of spermatozoa indicated that they lose three proteins (M(r) 28,000, 30,000 and 47,000) and gain one (M(r) 30,400) during passage through the epididymis. The method of determining protein secretion affected the findings. Protein secretion, its control and its association with spermatozoa are broadly similar in the tammar wallaby to the processes described in eutherian mammals.


1987 ◽  
Vol 40 (1) ◽  
pp. 37 ◽  
Author(s):  
MichaeI Messer ◽  
Christine Elliott

a-Lactalbumin was isolated from milk of M. eugenii and its concentration in milk samples taken at various times during lactation (0-40 we.eks post partum) was determined by single radial immunodiffusion using rabbit antiserum to the purified protein. The a-lactalbumin concentration remained almost constant throughout lactation even though the concentration of total lactose (free �lactose plus lactose contained in oligosaccharides) feli to zero after 34 weeks post partum. This fall in lactose was accompanied by a rise in the free galactose and glucose concentrations and marked increases in UDPgalactose hydrolase, nucleotide pyrophosphatase, alkaline phosphatase and acid fj-galactosidase activities. It is suggested that the in vitro hydrolysis of UDP-galactose was due to nucleotide pyrophosphatase and that this enzyme may also playa role in vivo late in lactation by making UDP-galactose unavailable for the synthesis of lactose. Alternatively, lactose and lactose-containing oligosaccharides might be degraded by the acid fj-galactosidase during or after secretion.


1969 ◽  
Vol 49 (2) ◽  
pp. 135-141 ◽  
Author(s):  
L. P. Milligan ◽  
A. R. Robblee ◽  
J. C. Wood ◽  
W. C. Kay ◽  
S. K. Chakrabartty

The preparation of a polymer of urea and furfural containing 23.2% nitrogen is described. This product was converted by rumen microorganisms in vitro to ammonia at a rate approximately one-seventh that of conversion of urea to ammonia. Use of the polymer as a dietary supplement in a feeding trial with lambs improved nitrogen retention over that of unsupplemented controls by 3.45 g of nitrogen retained per day, while an isonitrogenous quantity of supplemental urea improved nitrogen retention by 0.51 g of nitrogen retained per day. The blood urea pattern, throughout the day, of lambs adapted to control, urea-supplemented and urea–furfural polymer-supplemented rations indicated a slow, prolonged production of ammonia from the latter supplement and very rapid, short-term degradation of urea in vivo.


Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 325-338
Author(s):  
Elizabeth J. Thornber ◽  
Marilyn B. Renfree ◽  
Gregory I. Wallace

The in vitro uptake and incorporation of [3H]ui idine by blastocysts of the tammar wallaby showed a 16- and 30-fold increase from day 0 to day 10 after removal of pouch young, respectively. Two of the six non-expanded blastocysts recovered on day 5 showed a tenfold increase in incorporation. During the first ten days after removal of pouch young the diameter of the blastocyst increased threefold. Endometrial exudate from gravid uteri had a higher protein concentration than exudate from nongravid uteri (39·5 ± 0·9 and 32·0 ± 2·0 mg/ml (mean ± s.e.m.), respectively). Endometrial exudates from uteri where the blastocyst was actively growing were found to contain six uterine-specific proteins. These were separated by gradient polyacrylamide gel electrophoresis. Two of the proteins were pre-albumins and the others were larger molecules (M.W. 153000–670000). Two proteins were only present at particular stages of pregnancy: the other four were present at all stages from diapause to birth, in exudate from gravid and nongravid uteri. The specific binding of progesterone and androstenedione to proteins in endometrial exudates or uterine flushings from pregnant wallabies was less than one per cent of the value obtained from day-5 pregnant rabbits. The ability of mouse blastocysts to take up and incorporate [3H]uridine into acidinsoluble material increased threefold in the presence of day-10 endometrial exudates from wallabies. However, this was less than ten percent of the values obtained in the presence of bovine serum albumin. The concentration of calcium in endometrial exudates increased from 23·6 to 45·2 μg/ml during pregnancy; in endometrium it remained at 88·7 μg/g (wet weight) throughout pregnancy, and in plasma it was 53·3 μg/ml. The concentration of zinc in endometrial exudates was 4·5 μg/ml; in endometrium it decreased from 21·8 to 13·3 μg/g (wet weight) during pregnancy and in plasma it was 0·6 μg/ml.


2020 ◽  
Author(s):  
Rafael Muñoz-Tamayo ◽  
Juana C. Chagas ◽  
Mohammad Ramin ◽  
Sophie J. Krizsan

AbstractBackgroundThe red macroalgae Asparagopsis taxiformis is a potent natural supplement for reducing methane production from cattle. A. taxiformis contains several anti-methanogenic compounds including bromoform that inhibits directly methanogenesis. The positive and adverse effects of A. taxiformis on the rumen microbiota are dose-dependent and operate in a dynamic fashion. It is therefore key to characterize the dynamic response of the rumen microbial fermentation for identifying optimal conditions on the use of A. taxiformis as a dietary supplement for methane mitigation. Accordingly, the objective of this work was to model the effect of A. taxiformis supplementation on the rumen microbial fermentation under in vitro conditions. We adapted a published mathematical model of rumen microbial fermentation to account for A. taxiformis supplementation. We modelled the impact of A. taxiformis on the fermentation and methane production by two mechanisms, namely (i) direct inhibition of the growth rate of methanogenesis by bromoform and (ii) hydrogen control on sugars utilization and on the flux distribution towards volatile fatty acids production. We calibrated our model using a multi-experiment estimation approach that integrated experimental data with six macroalgae supplementation levels from a published in vitro study assessing the dose-response impact of A. taxiformis on rumen fermentation.Resultsour model captured satisfactorily the effect of A. taxiformis on the dynamic profile of rumen microbial fermentation for the six supplementation levels of A. taxiformis with an average determination coefficient of 0.88 and an average coefficient of variation of the root mean squared error of 15.2% for acetate, butyrate, propionate, ammonia and methane.Conclusionsour results indicated the potential of our model as prediction tool for assessing the impact of additives such as seaweeds on the rumen microbial fermentation and methane production in vitro. Additional dynamic data on hydrogen and bromoform are required to validate our model structure and look for model structure improvements. We are working on model extensions to account for in vivo conditions. We expect this model development can be useful to help the design of sustainable nutritional strategies promoting healthy rumen function and low environmental footprint.


1982 ◽  
Vol 30 (5) ◽  
pp. 767 ◽  
Author(s):  
DW Dellow ◽  
ID Hume

4. Digestion in the stomach, small intestine and large intestine of the red-necked pademelon (Thylogale thetis), the tammar wallaby (Macropus eugenii) and the eastern grey kangaroo (M. giganteus) fed on chopped lucerne hay freely was estimated in a slaughter experiment by reference to chromic sesquioxide added to the diet. Concentrations of volatile fatty acids and ammonia, and pH, indicated that microbial activity in the forestomach and large intestine (caecum and proximal colon) was extensive. In all 3 species virtually all of the soluble carbohydrate, 17% of apparently digestible crude protein, 62 to 65% of apparently digestible organic matter and 82 to 85% of digestible acid-detergent fibre were digested in the forestomach. There was a progressive loss of dietary substrates along the length of the forestomach; readily fermentable carbohydrate was digested largely in the sacciform forestomach and cranial region of the tubiform forestomach, and the rate of apparent loss of organic matter decreased along the tubiform forestomach.


1998 ◽  
Vol 22 ◽  
pp. 158-160
Author(s):  
J. Dijkstra ◽  
J. France ◽  
S. Tamminga

In protein evaluation systems for ruminants, the microbial protein supply is calculated from the amounts of rumen degradable organic matter and nitrogen (N) using empirical equations. A variable part of the rumen synthesized microbial protein does not reach the duodenum but is recycled within the rumen (review Firkins, 1996). Since energy is required for its re-synthesis and degraded microbial protein is subject to deamination, the efficiency of substrate conversion into microbial protein in the rumen is affected by microbial recycling. Rumen protozoa have a major impact upon this recycling through engulfment of micro-organisms and autolysis. In vitro, bacterial protein breakdown is proportionately reduced by some 0·9 upon removal of protozoa (Wallace and McPherson, 1987). Defaunation of the rumen increases the efficiency of microbial protein synthesis in vivo significantly (review Jouany et al., 1988).


1976 ◽  
Vol 231 (1) ◽  
pp. 44-51 ◽  
Author(s):  
RL Tannen ◽  
AS Kunin

Ammonia production by rat renal cortical mitochondria was studied with both in vivo and in vitro manipulation of potassium to further elucidate the mechanisms relating potassium homeostasis and renal ammonia production. Mitochondria from potassium-depleted animals demonstrated an increase in ammonia production at all glutamine concentrations studied, which ranged from 0.5 to 10 mM. This increase in ammoniagenesis compared favorably in degree of change with and was of sufficient absolute magnitude to entirely account for the findings observed both in renal cortical slices studied in vitro and in the intact animal. When rotenone is added to the medium, increased ammoniagenesis is still detected, indicating that either glutamine entry into the mitochondria and/or the activity of phosphate-dependent glutaminase are critical rate-controlling steps. In contrast to studies with renal slices, a decrease in ammonia production was not apparent with cortical mitochondria from chronically potassium-loaded animals. In vitro alterations of the potassium homeostasis. Therefore, these experimental manipulations either do not activate an effector mechanism which takes place in vivo, or the alteration in ammoniagenesis requires an adaptation over time that is not achieved with this in vitro approach.


Reproduction ◽  
2004 ◽  
Vol 128 (5) ◽  
pp. 595-605 ◽  
Author(s):  
Nadine M Richings ◽  
Geoffrey Shaw ◽  
Peter D Temple-Smith ◽  
Marilyn B Renfree

Here we report the first use of intra-cytoplasmic sperm injection (ICSI) in a marsupial, the tammar wallaby (Macropus eugenii ), to achieve in vitro fertilization and cleavage. A single epididymal spermatozoon was injected into the cytoplasm of each mature oocyte collected from Graafian follicles or from the oviduct within hours of ovulation. The day after sperm injection, oocytes were assessed for the presence of pronuclei and polar body extrusion and in vitro development was monitored for up to 4 days. After ICSI, three of four (75%) follicular and four of eight (50%) tubal oocytes underwent cleavage. The cleavage pattern was similar to that previously reported for in vivo fertilized oocytes placed in culture, where development also halted at the 4- to 8-cell stage. One-third of injected oocytes completed the second cleavage division, but only a single embryo reached the 8-cell stage. The success of ICSI in the tammar wallaby provided an opportunity to examine the influence of the mucoid coat that is deposited around oocytes passing through the oviduct after fertilization. The presence of a mucoid coat in tubal oocytes did not prevent fertilization by ICSI and the oocytes cleaved in vitro to a similar stage as follicular oocytes lacking a mucoid coat. Cell–zona and cell–cell adhesion occurred in embryos from follicular oocytes, suggesting that the mucoid coat is not essential for these processes. However, blastomeres were more closely apposed in embryos from tubal oocytes and cell–cell adhesion was more pronounced, indicating that the mucoid coat may be involved in maintaining the integrity of the conceptus during cleavage.


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