scholarly journals The effect of processing treatments on the rumen microbial digestion in vitro of skimmilk powder protein

1978 ◽  
Vol 50 (2) ◽  
pp. 147-154
Author(s):  
Eeva-Liisa Syväoja ◽  
Matti Kreula

The microbial degradation of the protein of skimmilk powders manufactured and treated in different ways (high-, medium-, and low-heat spray, instant, roller, formaldehyde-treated spray) and milk powder products (skimmilk powder-wheat flour granules, skimmilk powder-barley flour pellets) was determined in anaerobic, rumen simulating conditions in vitro. The tests showed that milk protein was decomposed rapidly and extensively in rumen fluid buffer. The heat treatment had a slight N solubility-reducing effect. Formaldehyde treatment decreased the degradation of the protein at the beginning of the incubation, but this effect became smaller as incubation proceeded. After 48 h the N solubility of the treated skimmilk powder was about the same as that of untreated spray powder. The variation in the in vitro N solubility of formaldehyde-treated skimmilk powder was greater than with the other powders and products. The skimmilk powder-wheat flour granules were hard products which remained indigestible for several hours. At the end of the microbial digestion test the addition of skimmilk powder increased the N solubility of wheat flour protein. On the basis of the results obtained from the digestion test on a pelleted skimmilk powder-barley flour product it can be assumed also that the addition of skimmilk powder caused an increase in the N solubility of barley flour protein.

1978 ◽  
Vol 50 (2) ◽  
pp. 166-176
Author(s):  
Liisa Syrjälä ◽  
Eeva-Liisa Syväoja ◽  
Marjatta Boman

The utilization of spray-dried fat free milk powder in three different froms 1) untreated, 2) treated with formaldehyde (0.4 g formaldehyde/100 g crude protein) and 3) pelleted with barley meal (30 % milk powder and 70 % barley meal) was studied with three rumen-fistulated dairy cows according to a 3 x 3 Latin square. The effects of different treatments were investigated with respect to rumen fermentation, microbial determinations and milk and blood analyses. The basic feed in every diet consisted of hay, grass silage, barley, oats, mineral and vitamin mixtures. Feeding was according to nutrient requirement. In each diet 25 % of the DCP required for milk production was replaced with milk protein. The NH3 concentration in the rumen fluid was lowest on the pelleted diet followed by the formaldehyde treated and untreated skimmilk powder diets, the differences only being significant between the pelleted and untreated diets. The pH values were significantly higher on the pelleted diet than on the other diets. The VFA content of the rumen fluid was similar on the different diets. The total amount of rumen ciliates was highest on the untreated skimmilk powder diet and lowest on the pelleted diet. The quantity of bacteria was however lower on the untreated skimmilk powder diet than on the other diets. Bacteria constituted 72—88 % of the total microbe mass on the different diets. The total microbe mass consisted of the following percentages of rumen content on the different diets: untreated 3.3 %, formaldehyde treated 3.2 % and pelleted diet 2,9 %. No effects on the milk yields and blood contents were found with the different treatments of skimmilk powder. Milk protein-% was significantly higher on the untreated skimmilk powder diet than on the pelleted diet.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 307
Author(s):  
Yuhui Zheng ◽  
Yanyan Zhao ◽  
Shenglin Xue ◽  
Wei Wang ◽  
Yajing Wang ◽  
...  

The feeding value of replacing concentrate with cassava (Manihot esculenta) residue in the feed of Holstein cows was confirmed using an in vitro gas test. The treatments consisted of 0% (control, CON), 5%, 10%, 15%, 20%, 25%, and 30% inclusion of cassava residue in fermentation culture medium composed of buffer solution (50 mL) and filtrated rumen fluid (25 mL). The parameters analyzed included the kinetics of gas production and fermentation indexes. Forty-eight hours later, there were no significant differences on in vitro dry matter disappearance (IVDMD), pH, and microbial crude protein (MCP) content among treatments (p > 0.05). However, the “cumulative gas production at 48 h” (GP48), the “asymptotic gas production” (A), and the “maximum gas production rate” (RmaxG) all increased linearly or quadratically (p < 0.01). The GP48 was significantly higher in the 25% treatment compared to the other treatments, except for the 30% (p < 0.01). The A was significantly larger in the 25% treatment compared to the other treatments, except for the 20% and 30% (p < 0.01). The RmaxG was distinctly larger in the 25% treatment compared to other treatments (p < 0.01); moreover, the “time at which RmaxG is reached” (TRmaxG) and the “time at which the maximum rate of substrate degradation is reached” (TRmaxS) were significantly higher in the 25% treatment than the CON, 20%, and 30% treatments (p < 0.01). Additionally, the content of ammonia-N (NH3-N) in all treatments showed linearly and quadratically decreases (p < 0.01), whereas total volatile fatty acid (VFA), iso-butyrate, butyrate, and iso-valerate contents changed quadratically (p = 0.02, p = 0.05, p = 0.01, and p = 0.02, respectively); all of these values peaked in the 25% treatment. In summary, the 25% treatment was associated with more in vitro gas and VFA production, indicating that this cassava residue inclusion level may be used to replace concentrate in the feed of Holstein cows. However, these results need to be verified in vivo.


1984 ◽  
Vol 52 (2) ◽  
pp. 239-247 ◽  
Author(s):  
John R. Ashes ◽  
Jim L. Mangan ◽  
Gurcharn S. Sidhu

1. Casein was labelled with pairs of radioactive amino acids, lysine, tyrosine and leucine, one with I4C and the other with 3H, by jugular infusion into lactating goats followed by isolation of the double-labelled casein from the milk. Total milk protein was similarly labelled by jugular infusion of [35S]cystine. U-14C-labelled fraction- 1 leaf protein was isolated from lucerne (Medicago sativa) grown in an atmosphere of 14C022. The proteins were treated withdifferent levels(333 and667 mmol/kgprotein) offormaldehyde, glutaraldehyde and glyoxal.3. Absorption from the small intestine was measured in sheep with fistulas in the abomasum and terminal ileum, using Cr-EDTA as the digesta flow marker, by introducing radioactive casein into the abomasum.4. Lysine, tyrosine and cystine became increasingly unavailable for absorption from the small intestine of sheep with increasing levels of aldehyde. At the lower level (333 mmol/kg) the proportions of the amino acids that were unavailable were 0.192, 0.051 and 0.123 respectively. At the higher level of formaldehyde (667 mmol/kg) the corresponding values were 0.335, 0.201 and 0.432 respectively. Leucine was not made unavailable with formaldehyde.5. The proportions of lysine, tyrosine and leucine that were unavailable were higher, on a molar basis, after treatment of the proteins with the dialdehydes glutaraldehyde and glyoxal than after treatment with formaldehyde. However, the extent of protein protection provided by the dialdehydes in the rumen, measured using an in vitro procedure, was lower.


1969 ◽  
Vol 23 (4) ◽  
pp. 763-782 ◽  
Author(s):  
H. Tagari ◽  
J. H. B. Roy

1. Four Ayrshire bull calves between 8 and 34 days of age and fitted with duodenal and ileal re-entrant cannulas were used to study the effect of heat treatment of the milk they received on the pH and nitrogen composition of the pyloric outflow and ileal contents.2. Milk A contained a spray-dried skim-milk powder pre-heated during the drying process at 74° for 30 min and milk B a similar powder pre-heated at 77° for 15 sec. In milk A about 50% of the non-casein protein N had been denatured.3. Milk B resulted in a lower pH than milk A in the pyloric outflow throughout the sampling period of 6.5 h after feeding. It resulted also in an increased volume of outflow during the 1st h after feeding, a reduced output of undigested protein, an increased output of non-protein nitrogen (NPN) and a different pattern of flow of NPN during the first 4 h after feeding.4. These differences between milk A and milk B were associated largely with different clotting characteristics, which were demonstrated in vitro at two levels of addition of rennet with or without the addition of calcium. The buffering capacity of the two milks was similar.5. Variation between calves in their response to these two milks was attributed to the age of the calves and to differences in inherent clotting or proteolytic activity.6. In the ileal outflow, bacterial activity, as measured by dehydrogenase activity, was positively related to N concentration, but the N concentration when milk A was given did not appear to differ from that when milk B was given.7. One calf had diarrhoea when given milk A at a young age. This was associated with an increased pyloric outflow, an increased outflow of undigested protein but little difference in the rate of proteolysis, and a high pH. In the ileal outflow the volume and amount of N was much increased although the N concentration was reduced.8. It is concluded that the detrimental effect of milk A, found in earlier experiments, was largely associated with high pH and poor digestibility of protein in the abomasum, conditions which allow multiplication of coliform organisms in the intestine.


1989 ◽  
Vol 69 (3) ◽  
pp. 727-734 ◽  
Author(s):  
P. S. MIR ◽  
J. H. BURTON ◽  
B. N. WILKIE ◽  
F. R. VAN DE VOORT

The effect of processing commercial soybean meal (HSBM) by either extrusion (ExSBM) or fermentation with microbes in rumen fluid (FSBM) on rate of protein hydrolysis and the activity of the antigen β-conglycinin was evaluated. Ethanol-extracted soybean meal (EtSBM) and skim milk powder (SMP) were included as positive controls while HSBM was the negative control, with regard to antigen content. The rates of proteolysis were determined by acid pepsin hydrolysis and the activity of β-conglycinin in the soluble fraction of the digestion mixtures at 0, 2, 4, 6 and 8 h of in vitro proteolysis was determined by radial immunodiffusion in agar gel containing antibody specific for the antigen. Susceptibility of FSBM and ExSBM to proteolysis by pepsin was greater than that of EtSBM. β-Conglycinin content was greatest in HSBM (1.0 ± 0.2 g dL−1) and only 0.3 ± 0.03 g dL−1 in ExSBM at the beginning of in vitro digestion. The antigen was not detected in either FSBM or EtSBM, therefore these products could be used in milk replacers for calves. Key words: In vitro pepsin proteolysis, extruded soybean meal, fermented soybean meal, antigen, β-conglycinin


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1836
Author(s):  
Hannah E. Zenker ◽  
Malgorzata Teodorowicz ◽  
Harry J. Wichers ◽  
Kasper A. Hettinga

For the determination of the binding of heated cow’s milk whey proteins such as β-lactoglobulin to the receptors expressed on immune cells, inhibition ELISA with the soluble form of the receptor for advanced glycation end products (sRAGE) and scavenger receptor class B (CD36) has been successfully used in the past. However, binding to heated and glycated caseins in this read-out system has not been tested. In this study, inhibition ELISA was applied to measure the binding of cow’s milk casein alone, as well as all milk proteins together, which underwent differential heat treatment, to sRAGE and CD36, and we compared those results to a dot blot read out. Moreover, binding to sRAGE and CD36 of differentially heated milk protein was measured before and after in vitro digestion. Casein showed binding to sRAGE and CD36, independent from the heat treatment, in ELISA, while the dot blot showed only binding to high-temperature-heated milk protein, indicating that the binding is not related to processing but to the physicochemical characteristics of the casein. This binding decreased after passage of casein through the intestinal phase.


1983 ◽  
Vol 34 (3) ◽  
pp. 289 ◽  
Author(s):  
B Tangendjaja ◽  
JP Hogan ◽  
RBH Wills

Samples of rumen fluid obtained from sheep that had been fed on different diets were fractionated into microorganism and supernatant fractions, and the former divided into bacteria-rich and protozoa-rich fractions. The fractions were evaluated for their ability to degrade purified mimosine during in vitro incubation. The rumen contents of sheep fed on a lucerne-oats mixture produced a more rapid degradation of mimosine than did that from sheep fed on lucerne hay, which was greater than that from a Digitaria pentrii diet. Most activity was in the bacteria-rich fraction for the lucerne-oats diet and in the protozoa-rich fraction for the other diets. The rate of degradation of endogenous mimosine in Leucaena leaf during incubation in ruinen fluid was much greater than for the purified mimosine. The substantial degradation observed when a buffer solution was substituted for rumen fluid was attributed to endogenous leaf enzymes. These enzyme systems were more efficient at degrading mimosine than were the microorganisms in the rumen liquor.


OENO One ◽  
1979 ◽  
Vol 13 (2) ◽  
pp. 125
Author(s):  
Serge Grenan

<p style="text-align: justify;">La multiplication végétative de la vigne cultivée <em>in vitro</em> à partir de boutures à un œil ayant 1 cm de longueur ne présente aucune difficulté technique. Par contre la propagation d'implants de plus petite taille s'avère délicate et aléatoire. Or l'élimination durable de virus thermorésistants nécessite le prélèvement (à la fin du thermotraitement) de très petites parties terminales de tiges.</p><p style="text-align: justify;">Des « boutures apicales » de 2 à 5 mm de longueur de <em>Vitis Vinifera</em> variété Grenache N, et de <em>Vitis Rupestris</em>, variété Lot ont été mises en culture sur un milieu de base additionné de diverses substances de croissance. L'AIA à la concentration 10-<sup>7</sup>M s'est révélé le régulateur favorisant le mieux la rhizogénèse des « boutures apicales ». Le transfert des « boutures apicales » enracinées sur le milieu de référence facilite leur croissance.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">Vegetative multiplication of vine grown <em>in vitro</em> from one-eyed-cuttings one centimeter long, does not present any technical difficulty. On the other hand, propagation of smaller implants is difficult and (random). The trouble is durable elimination of thermoresistant virus needs picking up (at the end of heat treatment) very small shoot tips.</p><p style="text-align: justify;">Apical cuttings of <em>Vitis Vinifera</em>, var. Grenache N. and of <em>Vitis Rupestris</em>, var. Lot two or five millimeters long are grown on a standard medium in which different growing substances are added. AIA at the concentration of 10-<sup>7</sup>M increases the best rhizogenesis of apical cuttings. The transfer of rooted cuttings upon the standard medium makes their growth easier.</p>


Author(s):  
A. Ruba Nanthini ◽  
C. Valli ◽  
L. Radhakrishnan ◽  
D. Balasubramanyam ◽  
A. Mangalagowri

Background: Rumen fluid has been used as microbial inoculum to treat indigestion in ruminant animals and to conduct in vitro rumen fermentation experiments. Lyophilization of the goat rumen fluid will provide continuous supply of rumen inoculums either for laboratory studies or for transfaunation in treating digestive disorders sequelae to high grain rations. However, no standard protocol is available for lyophilizing goat rumen fluid. Hence, this study was designed to develop a protocol to lyophilize goat rumen fluid as an alternate source for fresh goat rumen fluid. Methods: The study was conducted using 5 × 3 × 3 factorial design with four different cryoprotectants viz., 10% skim milk powder, 10% skim milk powder + 5% sodium glutamate, 5% glycerol, 5% DMSO and no cryoprotectant, at three pre freezing (2, 24 and 48 hours) and three freeze drying (8, 24 and 32 hours) time intervals to standardize protocol for lyophilizing goat rumen fluid. The viability of rumen microbes in the “lyophilized goat ruminal inoculum”, was determined via in vitro gas production study. Result: Pre freezing (-80°C deep freezer) duration of 48 hours with 32 hours of time duration in lyophilizer (-45°C) was ideal for lyophilizing goat rumen fluid with or without the addition of various cryoprotectants. Glycerol used at 5% as cryoprotectant resulted in significantly (P less than 0.05) highest gas production at all (12, 24 and 48) incubation hours studied indicating better viability of rumen microbes.


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