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PubMed1997

Ruminal undegradability of blood meal and effects of blood meal on ruminal and postruminal digestion in steers consuming vegetative orchardgrass hay.

Four crossbred steers (360 +/- 3 kg) cannulated at the rumen and duodenum were used in a 4 x 4 Latin square design to examine the effects of supplemental blood meal (BM) on voluntary intake, digesta kinetics, ruminal fermentation, site and extent of digestion, and bacterial protein synthesis in steers fed vegetative orchardgrass hay (Dactylis glomerata L.). The levels of BM supplementation were 0, .07, .13, and .20 kg/d. Voluntary intake of OM (8.35 kg/d) was not significantly affected by BM supplementation. No significant effects of BM supplementation were detected for OM flow to the duodenum or digestion in the rumen or lower tract. However, total tract OM digestibility decreased 2.2 percentage units at .20 kg/d of BM intake (lower with vs without BM; P < .10). Total N intake and flow to the duodenum linearly increased (P < .10) with increasing BM level from 251 to 277 g/d and from 158 to 199 g/d, respectively. Ammonia N and bacterial N flows to the duodenum were not affected (P > .10) by BM supplementation. As a result, nonammonia N flow to the duodenum increased linearly (P < .10) with increasing BM supplementation. Ruminal escape N from BM was 83.5, 85.3, and 87.2% for .07, .13, and .20 kg/d of BM, respectively. Apparent bacterial efficiency and true bacterial efficiency were not affected (P > .10) by BM supplementation. Total amino acid and total essential amino acid flows to the duodenum were increased (P < .10) by dietary inclusion of BM. Duodenal flows of all essential amino acids except lysine and valine and of all nonessential amino acids except alanine and proline were increased (P < .10) by BM inclusion in the diet. In summary, supplementation with BM increased ruminal escape N and duodenal flows of total and most essential amino acids.

Amino Acids↗
PubMed1987

Evaluation of rare-earth markers using an in vitro ruminal fermentation system and effect of processing method on ruminal turnover of sized corn particles.

A two-stage in vitro ruminal fermentation experiment was conducted to determine the extent of marker migration and the effects of marker addition on digestibility. Fermentation studies were terminated either at the end of stage I, the fermentation phase, or stage II, the pepsin digestion phase. Treatment diets contained ytterbium-marked corn plus chopped Coastal bermudagrass hay and nonmarked corn plus chopped hay. After stage I of the in vitro ruminal fermentation, 90% of ytterbium was recovered. Of this, 8.8% of the ytterbium had migrated to the hay, 2% was recovered in the supernatant and 89.2% remained bound to the corn. After completion of both stages, 72% was recovered, of which 7.9% was bound to corn, 33.6% was bound to the hay, 1.1% was recovered in the stage I supernatant and 57.4% was associated with the acid pepsin supernatant. Dry matter digestion was not affected after stage I but after stage II, digestibility was decreased 7% due to marker addition. A ruminal-cannulated Holstein steer weighing approximately 680 kg was used to determine turnover rates from the rumen of liquid and five different particle sizes of corn. Corn from each of two processing methods was fractionated into five particle sizes by dry-sieving. The corn particles included steam-rolled corn (SRC) retained on a 4-mm sieve and marked with dysprosium, SRC retained on a 2-mm sieve and marked with erbium, cracked corn (CC) retained on a 4-mm sieve and marked with yttrium, CC retained on a 2-mm sieve and marked with ytterbium, and CC retained on a 1-mm sieve and marked with samarium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2005

Subacute ruminal acidosis induces ruminal lipopolysaccharide endotoxin release and triggers an inflammatory response.

Subacute ruminal acidosis (SARA) was induced in 3 rumen fistulated Jersey steers by offering them different combinations of wheat-barley pellets and chopped alfalfa hay. Steers were offered 4, 5, and 6 kg/d of pelleted concentrate and 6, 5, and 4 kg/d of chopped alfalfa hay for diets 1, 2, and 3, respectively, during 5-d treatment periods and were fed chopped alfalfa hay between treatment periods. Inducing SARA increased blood concentrations of haptoglobin and serum amyloid-A. Dry matter intake of concentrate and hay decreased from d 1 to 5 in each period. Subacute ruminal acidosis was induced in all steers during d 4 and 5 when concentrate was fed, with ruminal pH remaining below 5.6 for an average of 187 and 174 min/d on these days. Lipopolysaccharide concentration increased significantly during periods of grain feeding compared with times when only hay was fed. Inducing SARA by feeding wheat-barley pellets activated a systemic inflammatory response in the steers.

Acidosis↗
PubMed1996

Ruminal availabilities of protein and starch: effects on growth and ruminal and plasma metabolites of dairy calves.

Newborn Holstein calves (n = 75) were blocked by date of birth and sex and assigned randomly to one of eight isonitrogenous starters that contained protein and starch sources of different ruminal availabilities. Soybean meal or soybeans roasted to an exit temperature of 146 degrees C, raw or conglomerated corn, and urea at 1% of DM or no urea were used in a 2 x 2 x 2 factorial arrangement. The conglomeration process consisted of grinding the grain, adding water, pelleting the mixture, and roasting, which increased the degree of starch gelatinization fivefold. Starters were fed for ad libitum intake from 0.5 to 8 wk. Urea supplementation of conglomerated corn starters depressed performance, but the depression was greater when conglomerated corn was used with soybean meal than when it was used with roasted soybeans. Ruminal NH3 and plasma urea increased with increased RDP in starters, but the response varied according to corn type and soy protein source. Urea supplementation depressed plasma Lys, doubled plasma Cit with soybean meal and conglomerated corn starters, but depressed plasma Cit with roasted soybeans and conglomerated corn starters. Conglomerated corn depressed plasma Val and Gly, and roasted soybeans increased plasma Phe. Performance was similar when calves consumed starters containing ruminally synchronous or asynchronous CP and starch sources.

Amino Acids↗
PubMed1997

The endogenous polysaccharide utilization rate of mixed ruminal bacteria and the effect of energy starvation on ruminal fermentation rates.

When mixed ruminal bacteria were starved in vitro for 24 h, cellular ATP decreased, but there was little change in cell protein. Starved ruminal bacteria derived most of their ATP from cellular polysaccharide. Because polysaccharide declined at a first-order rate of 23%/h, it was possible to estimate the endogenous polysaccharide utilization rate at various stages of starvation by multiplying the amount of utilizable polysaccharide remaining at each time point by 0.23. The bacteria initially had a rate of soluble carbohydrate fermentation that was > 717 micrograms of hexose equivalent/mg of protein per h. Starvation had little impact on the rate of soluble carbohydrate fermentation until 8 to 12 h, and the endogenous polysaccharide utilization rate was < 10 micrograms of hexose/mg of protein per h. The bacteria digested ball-milled cellulose at a rate of 24 micrograms of hexose/mg of protein per h for 8 to 12 h. Even bacteria that had been starved for 24 h fermented cellulose at a rate of 16 micrograms of hexose/mg of protein per h. The rate of methane production was initially 70 nmol of methane/mg of protein per min. Short periods of starvation (< 12 h) had little impact on methane production, but longer times caused an almost complete inhibition of methanogenesis. The rate of amino acid deamination was initially 31 nmol of ammonia/mg of protein per min, and the critical phase of starvation was again 8 to 12 h. Ruminal bacteria that were harvested at 24 h after feeding had 10-fold less polysaccharide than did bacteria that were harvested at 2 h after feeding, but this polysaccharide supported high rates of soluble carbohydrate and cellulose fermentation, deamination, and methane production.

Adenosine Triphosphate↗
PubMed1985

Gastrointestinal nematode infections in wild ruminants Rupicapra rupicapra and Dama dama: influence of density and cohabitation with domestic ruminants.

The distribution of gastrointestinal nematodes in different populations of wild ruminants has been studied with regard to density of the animals and the presence of domestic ruminants in the habitat. The degree of parasite overdispersion among the hosts has been examined in the hypothesis of a negative binomial model of distribution. The results show that the density has a greater weight than cohabitation with domestic ruminants, in destabilizing the host-parasite relationship.

Animals↗
PubMed2006

Development of an indirect ELISA for the detection of antibodies against Peste-des-petits-ruminants virus in small ruminants.

Peste des petits ruminants (PPR) is an acute, febrile, highly contagious and economically important viral disease of small ruminants. A polyclonal antibody based indirect ELISA was developed for detection of antibodies to PPR virus in the serum samples of goats and sheep using purified PPR viral antigen propagated in Vero cell culture. A threshold (cut-off) value was set as twice the mean of the negative population based on the distribution of known negative serum samples in respect of PPR virus antibodies in the test. A total of 1544 serum samples from goats and sheep were screened by indirect ELISA and competitive ELISA. The indirect ELISA compared very well with competitive ELISA, with a high degree of specificity (95.09%) and sensitivity (90.81%). When compared with virus neutralization test, the present assay had 100% specificity and 80% sensitivity. With serum samples, the assay could clearly differentiate animals from the infected population from uninfected ones. These results suggest that the indirect ELISA may be a good alternative tool to competitive ELISA for seroepidemiological surveys.

Animals↗
PubMed1993

Comparison of the ability to bind lipids of beta-lactoglobulin and serum albumin of milk from ruminant and non-ruminant species.

The interaction of sheep, horse, pig, human and guinea-pig whey proteins with fatty acids has been studied. Using gel filtration and autoradiography, it was found that sheep beta-lactoglobulin and serum albumin from all species had the ability to bind fatty acids in vitro. Sheep beta-lactoglobulin, isolated from milk, had approximately 0.5 mol fatty acids bound per mol monomer protein, and albumin from sheep, horse and pig contained approximately 4.5, 2.9 and 4.7 mol fatty acids/mol protein respectively. However, beta-lactoglobulin from horse and pig milk had neither fatty acids physiologically bound nor the ability to bind them in vitro. Albumin was the only whey protein detected with bound fatty acids in these species as well as in human and guinea pig. This suggests that the ability of ruminant beta-lactoglobulin to bind fatty acids was not shared by the same protein of non-ruminants.

Animals↗
PubMed1994

Transferrin receptors on ruminant pathogens vary in their interaction with the C-lobe and N-lobe of ruminant transferrins.

The interaction between ruminant transferrins and receptor proteins on the surface of the ruminant pathogens Pasteurella haemolytica, Haemophilus somnus, Pasteurella multocida, Haemophilus agnii, and Moraxella bovis was evaluated by a combination of binding assays and affinity isolation procedures. Membranes isolated from P. haemolytica, P. multocida, and H. agnii were capable of binding sheep, goat, and cattle transferrins whereas binding by membranes from H. somnus and M. bovis was specific for bovine transferrin. Proteolytically derived bovine transferrin C-lobe was capable of inhibiting the interaction between bovine transferrin and both Tbp1 and Tbp2 from P. haemolytica and M. bovis but only Tbp1 from H. somnus and P. multocida. Proteolytically derived N-lobe inhibited the binding of P. multocida and H. somnus Tbp2 to bovine transferrin and the binding of bovine transferrin to the single receptor protein identified in H. agnii. The implications of these results regarding the nature of the ligand-receptor interaction and similarities of this interaction with ligand-receptor interactions in different species are discussed.

Animals↗
PubMed1995

Survey of urease activity in ruminal bacteria isolated from domestic and wild ruminants.

A total of 909 strains, including Selenomonas ruminantium, Lactobacillus sp., Enterococcus sp. and Staphylococcus sp., from the rumen of 104 domestic and wild ruminants was used in tests for urease activity. Tests showed that 56.7% of S. ruminantium strains and 18.5% of lactobacilli manifested medium urease activity with mean values of 14.4 +/- 2.5 and 13.85 +/- 0.25 nkat ml-1, respectively. Most of the Enterococcus faecium (62.2%) and all of the E. faecalis isolates expressed urease activity with mean values of 3.9 +/- 0.05 and 4.1 +/- 0.06 nkat ml-1. E. malodoratus, E. solitarius, E. mundtii, Streptococcus bovis and S. uberis did not produce any urease. All the staphylococci screened were urease-producing strains, mostly with medium or low urease activity. The highest level of urease was measured in the rumen epithelial wall of isolates SE30 (19.7 +/- 2.71 nkat ml-1 of rumen content), SCU32 (29.3 +/- 1.6 nkat ml-1) and also in the rumen content isolates EF35 (19.9 +/- 0.94 nkat ml-1) and S. ruminantium 77 (25.35 nkat ml-1). This survey contributes new data to existing information relating to the ureolytic microbial ecosystem in ruminants.

Animals↗
PubMed2003

Development of a dual recombinant vaccine to protect small ruminants against peste-des-petits-ruminants virus and capripoxvirus infections.

A recombinant capripoxvirus vaccine containing a cDNA of the peste-des-petits-ruminants virus (PPRV) fusion protein gene was constructed. A quick and efficient method was used to select a highly purified recombinant virus clone. A trial showed that a dose of this recombinant as low as 0.1 PFU protected goats against challenge with a virulent PPRV strain.

Animal Diseases↗
PubMed1981

The activities and intracellular distributions of enzymes of carbohydrate, lipid and ketone-body metabolism in lactating mammary glands from ruminants and non-ruminants.

1. The activities of several enzymes of carbohydrate, lipid, acetate and ketone-body metabolism were measured in lactating mammary glands from rats, mice, rabbits, guinea pigs, sows, sheep, cows and goats. The intracellular distributions of many of the enzymes were measured by fractional extraction. 2. Acetyl-CoA synthetase was predominantly cytoplasmic in rats and guinea pigs, but was more mitochondrial in the other species. The different location of this enzyme in rats and mice is discussed in relation to the disposal of reducing equivalents. 3. 3-Oxo acid CoA-transferase and acetoacetyl-CoA thiolase assayed at 600 microM-CoA were predominantly mitochondrial in all species investigated. Acetoacetyl-CoA thiolase assayed at 8 microM-CoA was predominantly cytoplasmic, except in rabbits and guinea pigs. Ruminants appeared to possess little, if any, of the cytoplasmic enzyme. 4. The activities and distributions of NADP-isocitrate dehydrogenase were consistent with a role in supplying cytoplasmic NADPH in ruminant tissue, and indicated that this system may also occur in guinea pigs.

Acetates↗
PubMed1998

A review of selenium deficiency in grazing ruminants. Part 1: new roles for selenium in ruminant metabolism.

SELENIUM AVAILABILITY: Selenium deficiency has been an important source of loss to the pastoral industries of New Zealand. About 30% of farmed land in New Zealand is considered to be selenium-deficient and continued development of soils and pasture will tend to further decrease the concentration of selenium in pasture. BIOLOGICAL FUNCTIONS: Formerly it was believed that all biological functions of selenium in animals could be attributed to the antioxidant activity of the enzyme glutathione peroxidase. More recently, it has been shown that selenoproteins have roles in immune function and thyroid hormone metabolism. RESPONSES TO SUPPLEMENTATION: Following supplementation of ruminants grazing pastures deficient in selenium, milk production and growth responses are likely to occur in cattle, while in sheep improvements in growth and fertility are most likely. Reproductive dysfunction may not be as important as previously thought in cattle grazing pasture moderately deficient in selenium. The relationship between selenium intake and disease resistance deserves further study. CLINICAL RELEVANCE: Management of selenium deficiency will continue to be important in grazing ruminants. Veterinarians should be aware that many selenoenzymes exist, some with functions quite distinct from the antioxidant role of glutathione peroxidase.

Journal Article↗
PubMed1997

Bioavailability of ruminally protected sulfamethoxazole after oral administration in ruminating calves.

Bioavailabilities of oral rumen-protected and non-protected formulations of sulfamethoxazole (SMS) were compared in ruminating calves, since in vitro degradation of SMX in ruminal fluid was confirmed. The coated with a gastric-acid-soluble polymer and uncoated formulations were administered to 3 calves through a catheter. Neither formulation could produce sufficient blood concentration of the drug, though the bioavailability of SMX for the coated formulation was higher than that for the uncoated formulation. It was suggested that the rumen-protected drug could improve the bioavailability by escaping from degradation in the rumen, but scarcely attain the effective levels in blood.

Administration, Oral↗
PubMed1994

Improved techniques for dissociating particle-associated mixed ruminal microorganisms from ruminal digesta solids.

Combinations of physical and chemical methods were evaluated for their ability to remove particle-associated microorganisms (PAM) from saline-washed ruminal digesta solids (SWRDS). Physical methods included chilling and storage, homogenization, multiple extraction, and agitation with marbles. Chemical methods included use of low pH, Tween 80, formaldehyde, methanol, tertiary butanol, and methylcellulose. Microbial removal from SWRDS was determined directly by using epifluorescence microscopy and indirectly by measuring removal of diaminopimelic acid and total purines. Different combinations of methods resulted in removals of 46 to 82% for particle-associated bacteria (PAB), 52 to 98% for particle-associated protozoa (PAP), and 60 to 83% for PAB plus PAP. Two methods were considered most effective, based on microscopy; both removed similar amounts of PAB (79 to 82%) and PAB plus PAP (80 to 83%). In one method, SWRDS were stored for 24 h at 4 degrees C in a solution of pH 2 saline, .1% Tween 80, 1.0% methanol, and 1.0% tertiary butanol. In the other method, SWRDS were incubated for 30 min in .1% methylcellulose before storage for 24 h at 4 degrees C in pH 2 saline, .1% Tween 80, and 1.0% methanol. Common to both treatments was subsequent homogenization of the suspensions for 15 s followed by washing the digesta solids seven times with the treatment solutions. Both methods resulted in values that exceeded those reported previously for removal of PAM from ruminal digesta solids.

Animal Feed↗
PubMed2002

The effect of a ruminal nitrogen (N) deficiency in dairy cows: evaluation of the cornell net carbohydrate and protein system ruminal N deficiency adjustment.

Twenty-four multiparous and fifteen first lactation Holstein cows averaging 263 days in milk and weighing 614 kg were fed diets adequate or deficient in ruminal nitrogen (N), based on predictions of the Cornell Net Carbohydrate and Protein System (CNCPS). After adjustment to a low crude protein (CP) total mixed rations (TMR; 12.6% CP), the cows were allocated to 13 blocks based on lactation number, milk production, body condition score, and body weight. Within each block, cows were randomly assigned to one of the 3 treatment (TRT) diets (9.4, 11.1 and 14.1% CP for TRT 1, 2, and 3, respectively). All diets contained the same proportion of high moisture corn, chopped grass hay, and minerals, with urea substituted for corn silage as needed to reach the three CP levels. The TRT diets were then fed to the cows for 4 wk. Milk production was significantly affected by TRT: 15.5, 18.8, and 21.7 kg/d for TRT diets 1, 2, and 3, respectively. DMI was increased significantly as the percentage of CP increased from 9.4 to 14.1% CP: 17.6, 20.0, and 21.2 kg/d for TRT diets 1,2, and 3, respectively. CNCPS predictions for production (with and without the N adjustment for ruminal N deficiency) of metabolizable protein (MP) allowable milk were compared with observed milk production. Using the average individual weekly cow data from all 3 TRT, we found that the CNCPS accounted for 72 and 68% of the variation in MP allowable milk without and with the N deficiency adjustment, respectively. The overall mean bias without the N adjustment was 3.3 kg of milk (over prediction model bias of 14.6%, P < 0.001), and the N adjustment reduced the model over-prediction bias to 0.01 kg of milk (P = 0.96).

Animal Nutritional Physiological Phenomena↗
PubMed2006

Evaluation of models to describe ruminal degradation kinetics from in situ ruminal incubation of whole soybeans.

Different mathematical models were evaluated as candidates to describe ruminal dry matter (DM) and crude protein (CP) degradation kinetics of raw and roasted whole soybeans from data obtained using the in situ polyester bag technique. Three models were used: segmented with up to 3 straight lines (model I), negative exponential (model II), and rational function or inverse polynomial (linear over linear; model III). A fourth, a generalized sigmoidal model, was also considered but the data did not exhibit sigmoidicity, so it was dropped from the analysis. Lagged and nonlagged versions of each model were fitted to the DM and CP disappearance curves of 6 different feeds (2 cultivars of raw or differently heat-processed whole soybean). The comparison between lagged and nonlagged versions of each model, based on statistical and behavior characteristics, showed for all models that the discrete lag parameter did not significantly improve the fit to ruminal DM and CP disappearance curves. The comparison between models (using nonlagged equations) showed that models I and II gave better goodness-of-fit than model III. Based on biological characteristics, models II and III underestimated the undegradable DM and CP fractions, but there was no significant difference between models for extent of degradation.

Animal Feed↗
PubMed1989

Effect of ammoniated barley silage on ruminal fermentation, nitrogen supply to the small intestine, ruminal and whole tract digestion, and milk production of Holstein cows.

The effect of ammonia on barley silage fermentation characteristics, and the digestion and utilization of ammoniated barley silage by lactating Holstein cows fed three isonitrogenous diets (14.5% CP, DM basis) were examined. Whole plant barley was chopped and treated with anhydrous ammonia (1%, DM basis) at ensiling. Untreated barley silage was supplemented with either canola meal or urea. Cows were fed complete mixed diets (50% silage and 50% concentrate mixture, DM basis). Addition of ammonia increased total N, water-insoluble N, lactic acid, and pH in silage. Based on the application rate, 77.7% of the added ammonia N was recovered, and increased water-insoluble N was equal to 49.8% of added ammonia N. Addition of ammonia to barley silage increased ruminal concentrations of ammonia and propionate, and supplies of nonammonia N, microbial N, and total N to the small intestine. Ruminal effective degradabilities of DM and CP of barley silage and complete mixed diets, and whole tract digestibility of DM and CP of complete mixed diets were not affected by supplemental N source. Milk yield and milk composition of cows fed the ammoniated barley silage were similar to those of cows fed the diets supplemented with canola meal or urea.

Ammonia↗