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PubMed2006

Attention difficulties and mood-related ruminative response style in adolescents with unipolar depression.

BACKGROUND: Depressed adults may show impairment in switching attention from one task to another. Rumination on negative thoughts is associated with the onset and persistence of depressive episodes. It is unclear if such mood-related ruminations are specifically associated with slowed ability in switching attention from one task to another. METHOD: Adolescents with current unipolar depression (n = 40) were compared with age and sex-matched controls (n = 38) on tests of attention and general cognitive abilities and completed the mood-related ruminative response style questionnaire. RESULTS: Compared to controls, depressed participants were significantly slower at switching attention. There was no association between attentional switching and mood-related ruminations and both processes contributed to the likelihood of being depressed. Findings were not accounted for by slowness in reading and speaking, the effects of antidepressants nor being more careful on tasks. CONCLUSIONS: Depressed adolescents demonstrate dual deficits in mood-related ruminative thinking and attention. Further studies are needed to investigate whether higher ruminations are associated with attention impairments in emotionally-valent attentional switching tasks, and whether both processes precede the emergence of clinical disorder.

Adolescent↗
PubMed2006

Short- and long-term outcome and factors predicting survival after surgical tube cystostomy for treatment of obstructive urolithiasis in small ruminants.

OBJECTIVE: To evaluate outcome of small ruminants after tube cystostomy without urethral flushing. STUDY DESIGN: Retrospective clinical study. ANIMALS: Small ruminants (n=63; 50 goats, 13 sheep). METHODS: Medical records (January 1996-October 2003) for all small ruminants undergoing tube cystostomy were analyzed. Signalment, laboratory data, intraoperative findings, urolith type, and postoperative outcome were compared. Long-term follow-up was obtained at 6 and > or= 12 months postoperatively. RESULTS: Most animals were castrated males. Pygmy goats were overrepresented. Mean time to normal urination after tube cystostomy was 11 days, and mean hospitalization was 14 days. Seventy-six percent of animals were successfully treated with tube cystostomy (90% of those discharged from hospital). Short- and long-term survival was good for those animals with follow-up data. Reobstruction occurred in <20% of animals at 6 and 12 months. Goats, castrated males, and animals with normal serum potassium, no fluid in the abdomen, or no urethral process amputation were more likely to survive. Stone type, bladder appearance, and age at castration were not associated with outcome. CONCLUSION: Surgical tube cystostomy without urethral flushing is an effective technique for resolution of obstructive urolithiasis in small ruminants. CLINICAL RELEVANCE: Goats, small ruminants with an intact urethral process, absence of abdominal fluid, and serum potassium concentration <5.2 mEq/L at admission were all associated with survival after tube cystostomy. Castrated males may also be more likely to survive. These factors should be considered in management of small ruminants with urolithiasis.

Animals↗
PubMed2000

Unravelling the genetic diversity of ruminal bacteria belonging to the CFB phylum.

Molecular biology approaches were employed to examine the genetic diversity of bacteria from the Cytophaga/Flexibacter/Bacteroides (CFB) phylum in the rumen of cattle. By this means we were able to identify cultured strains that represent some of the larger CFB clusters previously identified only by PCR amplification and sequencing. Complete 16S rDNA sequences were obtained for 16 previously isolated rumen strains, including the type strains of Prevotella ruminicola, P. bryantii, P. brevis and P. albensis to represent a wide range of diversity. Phylogenetic analysis of cultured strains revealed the existence of three clusters of ruminal CFB: (i) a cluster of Prevotella strains, which have been found only in the rumen, including the two type strains, P. brevis GA33(T) and P. ruminicola 23(T); (ii) Prevotella spp. that cluster with prevotellas from other ecological niches such as the oral cavity and which include the type strains, P. bryantii B(1)4(T) and P. albensis M384(T); (iii) two Bacteroides spp. strains clustering with B. forsythus of oral origin. In order to establish whether the cultivated isolates cover the whole range of ruminal CFB genetic diversity, 16S rRNA gene sequences were amplified and cloned from DNA extracted from the same rumen samples (one cow in Slovenia, one in Scotland and three in Japan). Sequencing and phylogenetic analysis of 16S rRNA genes confirmed the existence of two superclusters of ruminal Prevotella, one exclusively ruminal and the other including non-ruminal species. In the case of ruminal Bacteroides spp., however, phylogenetic analysis revealed the existence of three new superclusters, one of which has as yet no cultivable counterpart. Interestingly, these Bacteroides clusters were represented almost exclusively by clone libraries from the Japanese cattle and only three sequences were from the European cattle. This study agrees with previous analyses in showing that rumen Prevotella/Bacteroides strains exhibit a remarkable degree of genetic diversity and suggests that different strain groupings may differ greatly in their recovery by cultural methods. The most important conclusion, however, is that cultured strains can be identified that represent some of the larger clusters previously identified only by PCR amplification and sequencing.

Journal Article↗
PubMed2002

The effect of bovicin HC5, a bacteriocin from Streptococcus bovis HC5, on ruminal methane production in vitro.

Methane represents a loss of feed energy to ruminant animals, and nutritionists have sought methods of inhibiting ruminal methane production. When mixed ruminal bacteria (approximately 400 mg protein ml(-1)) from a cow fed timothy hay were incubated in vitro with carbon dioxide and hydrogen (0.5 atm) for less than 8 h, the first-order rate of methane production was 17 micromol ml(-1). Semi-purified bacteriocin from Streptococcus bovis HC5 (bovicin HC5) inhibited methane production, by as much as 50%, and even a low concentration of bovicin HC5 (128 activity units (AU) ml(-1)) caused a significant decrease. Mixed ruminal bacteria that were transferred successively retained their ability to produce methane from carbon dioxide and hydrogen, and the first-order rate of methane production did not decrease. Cultures that were treated with bovicin HC5 (128 AU ml(-1)) gradually lost their ability to produce methane, and methane was not detected after four transfers. These latter results indicated that ruminal methanogens could not adapt and become resistant to bovicin HC5. When the chromosomal DNA was amplified with 16S rDNA primers specific to archaea, digested with restriction enzymes (HhaI and HaeIII) and separated on agarose gels, approximately 12 fragments were observed. DNA from control and treated cultures (third transfer) had the same fragment pattern indicating bovicin HC5 was not selective. Given the perception that the routine use of antibiotics in animal feeds should be avoided, bacteriocins may provide an alternative strategy for decreasing ruminal methane production.

Animals↗
PubMed1988

Comparisons of ruminal fermentation characteristics and microbial populations in bison and cattle.

Ruminal microbial populations, fermentation characteristics, digestibility, and liquid flow rates in two ruminally cannulated bison and two ruminally cannulated Hereford steers fed a prairie hay diet were compared. No significant differences in anaerobic bacterial counts, volatile fatty acid concentrations, or ruminal pHs were evident between bison and cattle. Also, no significant differences in neutral detergent fiber digestibility, indigestible fiber retention time, or intake were detected between bison and cattle, although cattle had higher levels (P less than 0.08) of ruminal dry matter and indigestible fiber than bison. Bison had a smaller (P = .02) ruminoreticular volume, faster liquid dilution rates, and faster liquid turnover times than cattle. The average ruminal ammonia nitrogen concentration was higher (P = 0.02) in bison (1.17 mg/dl) than in cattle (0.79 mg/dl). Total ciliate protozoal counts and cell volume were greater (P = 0.07) in bison (32.8 x 10(4)/g and 407.1 x 10(-4) ml/g, respectively) than in cattle (15.7 x 10(4)/g and 162.2 x 10(-4) ml/g, respectively). Bison harbored higher (P less than 0.02) numbers of Dasytricha spp., Eudiplodinium maggii, Eudiplodinium bursa, and Epidinium spp. than cattle and possessed a type B protozoan population. The cattle possessed a mixed type A-type B population that was characterized by Ophryoscolex spp. and Polyplastron spp. in association with low concentrations of Epidinium spp. and Eudiplodinium maggii.

Animal Feed↗
PubMed1992

Moderation of ruminal fermentation by ciliated protozoa in cattle fed a high-grain diet.

The objective of this study was to assess the influence of ciliated protozoa on ruminal fermentation in cattle fed high-grain diets. Six ruminally cannulated steers fed a corn-based grain diet (85% concentrate plus 15% alfalfa hay) at 12-h intervals were assigned randomly to two groups, ciliate free and faunated, in a crossover design. Defaunation was by ruminal emptying, omasal flushing, and treatment with sodium sulfosuccinate. Two to 3 weeks after defaunation, the ruminal contents of all steers were sampled before the morning feeding (0 h) and at 1, 2, 4, 6, 8, and 12 h after feeding to measure pH, analyze fermentation products, and monitor counts of ciliated protozoa and lactic acid-producing and -fermenting bacterial groups. Total numbers of ciliated protozoa in the faunated steers averaged 4.3 x 10(5)/g, and the protozoa consisted of nine genera. Ciliate-free steers had lower (P less than 0.01) ruminal pHs (pH 5.97) than faunated cattle (pH 6.45); however, the treatment-time interaction was not significant. Ruminal lactate and ammonia concentrations were similar in both groups. The total volatile fatty acid concentration was higher (P less than 0.05) in the ciliate-free steers than in the faunated steers and exhibited a treatment-time interaction (P less than 0.05). The acetate-to-propionate ratio was higher (P less than 0.05) in the faunated group than in the ciliate-free group and showed a treatment-time interaction (P less than 0.05). Total anaerobic bacterial counts were about fourfold higher in the ciliate-free group than in the faunated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Metabolism of the plant toxins nitropropionic acid and nitropropanol by ruminal microorganisms.

The nitro toxins 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH), which are found in many leguminous plants, are known to be detoxified by ruminal microorganisms. The rates of the detoxification reactions are critical to acquisition of tolerance to the plants by ruminant animals, but further information is needed about factors which influence reaction rates and about the nature of the detoxification reactions. We found that rates of disappearance of NPA and NPOH varied somewhat between samples of ruminal fluid but were usually about 0.4 and 0.1 mumol/ml of ruminal fluid per h, respectively, and that rates with threefold-concentrated cells from rumen fluid were correspondingly higher. We present evidence that ruminal microbes from both cattle and sheep reduce these nitro groups in situ, so that NPA is converted to bet-alanine and NPOH is converted to 3-amino-1-propanol. These products were identified by thin-layer chromatography and, as their dabsyl derivatives, separated by high-performance liquid chromatography. The product beta-alanine was itself metabolized by these mixed suspensions of rumen microbes, so its recovery was always less than what would be estimated from NPA loss, but as much as 87% of the NPOH lost from incubation mixtures was recovered as 3-amino-1-propanol. Addition of sulfide and ferrous ions to suspensions of ruminal microbes increased the rate of NPOH reduction about threefold, but rates of NPA reduction were not similarly increased. When incubations were under hydrogen gas instead of carbon dioxide, the addition of sulfide and ferrous ions led to even greater (five- to eightfold) increases in the rates of NPOH metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Propanol↗
PubMed1994

Ability of Acidaminococcus fermentans to oxidize trans-aconitate and decrease the accumulation of tricarballylate, a toxic end product of ruminal fermentation.

Mixed ruminal bacteria convert trans-aconitate to tricarballylate, a tricarboxylic acid which chelates blood divalent cations and decreases their availability (J. B. Russell and P. J. Van Soest, Appl. Environ. Microbiol. 47:155-159, 1984). Decreases in blood magnesium in turn cause a potentially fatal disease known as grass tetany. trans-Aconitate was stoichiometrically reduced to tricarballylate by Selenomonas ruminantium, a common ruminal bacterium in grass-fed ruminants (J. B. Russell, Appl. Environ. Microbiol. 49:120-126, 1985). When mixed ruminal bacteria were enriched with trans-aconitate, a trans-aconitate-oxidizing bacterium was also isolated (G. M. Cook, F. A. Rainey, G. Chen, E. Stackebrandt, and J. B. Russell, Int. J. Syst. Bacteriol. 44:576-578, 1994). The trans-aconitate-oxidizing bacterium was identified as Acidaminococcus fermentans, and it converted trans-aconitate to acetate, a nontoxic end product of ruminal fermentation. When S. ruminantium and A. fermentans were cocultured with trans-aconitate and glucose, tricarballylate never accumulated and all the trans-aconitate was converted to acetate. Continuous-culture studies (dilution rate, 0.1 h-1) likewise indicated that A. fermentans could outcompete S. ruminantium for trans-aconitate. When mixed ruminal bacteria were incubated in vitro with 10 mM trans-aconitate for 24 h, 45% of the trans-aconitate was converted to tricarballylate. Tricarballylate production decreased 50% if even small amounts of A. fermentans were added to the incubation mixes (0.01 mg of protein per mg of mixed bacterial protein). When A. fermentans (2 g of bacterial protein) was added directly to the rumen, the subsequent conversion of trans-aconitate to tricarballylate decreased 50%, but this effect did not persist for more than 18 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Aconitic Acid↗
PubMed1996

An rRNA approach for assessing the role of obligate amino acid-fermenting bacteria in ruminal amino acid deamination.

Ruminal amino acid degradation is a nutritionally wasteful process that produces excess ruminal ammonia. Monensin inhibited the growth of monensin-sensitive, obligate amino acid-fermenting bacteria and decreased the ruminal ammonia concentrations of cattle. 16S rRNA probes indicated that monensin inhibited the growth of Peptostreptococcus anaerobius and Clostridium sticklandii in the rumen. Clostridium aminophilum was monensin sensitive in vitro, but C. aminophilum persisted in the rumen after monensin was added to the diet. An in vitro culture system was developed to assess the competition of C. aminophilum, P. anaerobius, and C. sticklandii with predominant ruminal bacteria (PRB). PRB were isolated from a 10(8) dilution of ruminal fluid and maintained as a mixed population with a mixture of carbohydrates. PRB did not hybridize with the probes to C. aminophilum, P. anaerobius, or C. sticklandii. PRB deaminated Trypticase in continuous culture, but the addition of C. aminophilum, P. anaerobius, and C. sticklandii caused a more-than-twofold increase in the steady-state concentration of ammonia. C. aminophilum, P. anaerobius, and C. sticklandii accounted for less than 5% of the total 16S rRNA and microbial protein. Monensin eliminated P. anaerobius and C. sticklandii from continuous cultures, but it could not inhibit C. aminophilum. The monensin resistance of C. aminophilum was a growth rate-dependent, inoculum size-independent phenomenon that could not be maintained in batch culture. On the basis of these results, we concluded that the feed additive monensin cannot entirely counteract the wasteful amino acid deamination of obligate amino acid-fermenting ruminal bacteria.

Amino Acids↗
PubMed1992

Ruminal lactic acidosis in sheep and goats.

The clinical findings in 37 sheep and goats with acute ruminal lactic acidosis included a disturbed general condition characterised by anorexia, apathy, teeth grinding and muscle twitching, ruminal stasis, and the excretion of soupy or watery faeces. The ruminal fluid of affected animals was milky, had a sour odour and a low pH. There was a predominance of Gram-positive bacteria in smears of ruminal fluid. In comparison with 10 control animals, the rumen fluid of 23 sheep with ruminal lactic acidosis had higher lactic acid and lower volatile fatty acid concentrations. In addition, the affected animals often had haemoconcentration and metabolic acidosis. Treatment included single or repeated transfer of ruminal fluid from healthy cows and, depending on the severity, the administration of antacids, yeast and chlortetracycline, and the intravenous infusion of isotonic sodium chloride and 5 per cent sodium bicarbonate solutions. Of the 37 treated sheep and goats, four died within 24 hours, and three others were euthanased after one, two and three days because their condition rapidly deteriorated. Thirty animals were discharged one to nine days after treatment. Twenty-nine of them (78.4 per cent) recovered completely but one was euthanased later.

Acetates↗
PubMed2003

Can't quite commit: rumination and uncertainty.

Why do some individuals persist in self-destructive rumination? Two studies investigated the relation between a ruminative response style and the reluctance to initiate instrumental behavior. In Study 1, ruminators were compared to nonruminators regarding their evaluation of a self-generated plan to revise their university housing system and, in Study 2, concerning their plan to redesign the undergraduate curriculum. In both studies, on relevant composite measures, ruminators expressed less satisfaction and confidence with regard to their plans than did nonruminators. They were also less likely to commit to the plans they generated. The findings suggest that in addition to its documented detrimental effects on thinking and problem solving, self-focused rumination may inhibit instrumental behavior by increasing uncertainty, resulting in further rumination and behavioral paralysis.

Adult↗
PubMed2006

Non-abusive mothers of sexually abused children. The role of rumination in maternal outcomes.

This study of 125 mothers examined the role of rumination in maternal emotional and behavioral outcomes subsequent to discovery of the sexual abuse of their children. Abuse severity, a maternal history of child abuse experiences, and life hassles were examined as predictors of negative outcomes. The central finding was that these factors, many of which are not controllable, were less likely to predict poor maternal outcomes than was rumination, a cognitive process that may be alterable. Rumination was the strongest correlate with each outcome. Further, the effects of most predictors on outcomes in this study were mediated by a ruminative cognitive style. Abuse severity, income, ethnicity, and education lacked significant relationships with maternal outcomes. This study asserts that rumination is a central component for understanding maternal outcomes in the post-discovery phase of sexual abuse cases. It recommends that rumination be routinely assessed both for research and treatment purposes.

Anger↗
PubMed2006

Pain perception as a function of self-focused rumination.

Pain sensitivity and tolerance were studied using the cold-pressor technique. A 3 independent groups design was employed using rumination as the independent variable. Group 1 was given a situation in which anger-related self-rumination was introduced. Group 2 was given a self-related rumination task in which anger was not induced. Group 3 received a rumination task not related to the self. In addition, the State-Trait Anger Expression Inventory was given prior to the experiment to test the hypothesis that ratings on the Anger-In subtest would correlate with pain sensitivity. In each group were 6 men and 6 women. Each participant took the anger and another inventory not relevant to the present study before the experiment. An anger measure was taken before and after the experiment for each group to see if the anger induction in Group 1 actually increased anger. There were no differences among the 3 groups on the second anger measure, so differences between Groups 1 and 2 could not be attributed to anger. A 1-way analysis of variance for 3 groups showed a strong main effect on pain tolerance but not pain sensitivity. Groups 1 and 2 were significantly more tolerant of pain than Group 3. The correlation of ratings on the Anger-In (internalized anger) subtest fell short of statistical significance with pain sensitivity and also was not significant for pain tolerance. Results were discussed in terms of the possibility that self-rumination may increase pain tolerance by requiring a greater cognitive load than nonself rumination.

Anger↗
PubMed1990

Fragmentation and ruminal escape of particles as related to variations in voluntary intake, chewing behavior and extent of digestion of potentially digestible NDF in heifers.

The distribution of particles of differing sizes in ruminal, duodenal and fecal samples, the efficiency of particle breakdown and ruminal escape and their relationships to voluntary intake, chewing behavior and extent of digestion of potentially digestible NDF were examined in six heifers (290 kg average BW) with ruminal, duodenal and ileal cannulas. Animals had ad libitum access to corn silage, with or without 100 mg monensin head-1.d-1, in a two-period crossover design. Variations in voluntary intake by individual animals were positively related to size of digesta particles (median retaining aperture, MRA) in the dorsal rumen (P = .07) and rectum (P = .08), but not to MRA of particulate matter from the ventral rumen and duodenum. No significant relationships existed among eating or ruminating activities and distribution of particles of differing sizes in digesta from any of the digestive sites. The MRA of particulate matter in duodenal and rectal digesta were negatively related (P = .08 and P = .10) to extent of digestion of potentially digestible NDF (PDNDF) at these sites. Voluntary intake was related positively to efficiency of ruminative degradation of digesta particles appearing at the duodenum (P = .09) and to duodenal DM digesta flow per opening of the reticulo-omasal orifice (ROO; P = .02), the latter being negatively related to extent of digestion of PDNDF in duodenal digesta (P = .09). These results suggest that animals with higher intake capability are more efficient ruminators and can partially override constraining factors of particle size and byoyancy and thereby achieve a larger amount of DM flowing per opening of the ROO.

Animal Feed↗
PubMed1990

Effects of chewing behavior and ruminal digestion processes on voluntary intake of grass silages by lactating dairy cows.

Four primiparous Holstein-Friesian cows (518 kg average BW) with ruminal and duodenal cannulas were used to examine voluntary intake of direct cut (DC) or wilted (W) grass silage in relation to ruminal characteristics and chewing behavior. Dry matter content of the silages was 17.0 and 38.1%, concentrate DM intake was restricted to 5.0 and 5.3 kg/d, and voluntary DM intake from silages averaged 7.4 and 9.5 kg/d (P = .008), respectively. The acetate/propionate ratio in ruminal fluid decreased from 4.0 on DC to 3.3 on W silage (P = .021). The protein content in milk increased from 26.3 to 27.5 g/liter (P = .042) and the protein yield from 469 to 574 g/d (P = .038). The distribution of concentrates (38% of DM intake) with a mean particle size of .04 cm reduced differences in fecal mean particle size between diets. There was a shift from eating to ruminating on W silage with regard to daily duration (min/d) and number of jaw movements (no./d). However, ruminating index (no./kg DM intake) remained unchanged, irrespective of wilting and chop length of the silages or physiological state of the animals. These results are interpreted to indicate that the time lag for functional density of feed particles in the reticulorumen to increase, as affected by ruminating activity, not rate of reduction of the particle size, limits voluntary intake of grass silage by cattle.

Animals↗
PubMed1990

Effects of lecithin and corn oil on site of digestion, ruminal fermentation and microbial protein synthesis in sheep.

Six Hampshire wethers with ruminal and duodenal cannulas were fed three diets in a replicated 3 X 3 latin square to compare phospholipids with triglycerides for their effects on ruminal digestion. The diets (56% concentrate, 44% bermuda-grass hay, air-dried basis) contained either no added fat (control), 5.2% soybean lecithin or 2.4% corn oil on a DM basis. All diets were isonitrogenous and both fat-supplemented diets had similar fatty acid and energy contents. Fat added to the diet, regardless of source, reduced digestibilities of DM, energy, ADF and fatty acids in the rumen but had no effect on total tract digestibility coefficients. Lecithin slightly increased (P = .06) fatty acid digestion in the hindgut compared to corn oil (91.0 and 87.0%, respectively). Both fat sources decreased (P less than .01) ruminal ammonia concentration and increased (P less than .10) N flow to the duodenum. Added fat also reduced ruminal (P less than .01) and total tract (P less than .05) N digestibilities. Microbial N flow to the hindgut was not affected by diet, but adding fat increased (P less than .06) true efficiency of microbial protein synthesis. Overall, phospholipids from soybean lecithin inhibited ruminal fermentation similarly to triglycerides from corn oil. Despite ruminal degradation of lecithin by microbial phospholipases as shown in other studies, feeding lecithin tended to increase fatty acid digestion in the hindgut.

Animals↗
PubMed1990

Factors that determine rates of cyanogenesis in bovine ruminal fluid in vitro.

Strained ruminal fluid was collected from cattle fed five diets at two locations to determine in vitro rates of cyanogenesis from the glycosides amygdalin, prunasin and linamarin. Rates of dissociation for the corresponding aglycones, benzaldehyde cyanohydrin and acetone cyanohydrin, also were determined. Hydrogen cyanide (HCN) in ruminal fluid was determined with a modified method of HCN analysis that independently measured the overall rate of cyanogenesis and the nonenzymatic dissociation of cyanohydrins, the intermediate products in the degradation of cyanogenic glycosides to HCN. Rate of dissociation of cyanohydrins in ruminal fluid was pH-dependent, with high rates of dissociation (as expressed by the rate constant or half-life of the reaction) occurring at pH greater than 6 and slower rates at pH 5 to 6. Cyanohydrin dissociation was most rapid when cattle were fasted for 24 to 48 h and ruminal pH was high; rate of dissociation was much slower during feeding and digestion. When the glycosides were examined, highest rates of cyanogenesis (mg HCN.liter-1.s-1) were observed after a 24-h postprandial period. Hence, cattle are most susceptible to poisoning by cyanogenic plants when the pH of ruminal fluid is elevated (for rapid dissociation) and also when the activity of microbial beta-glucosidase is adequate for rapid hydrolysis of glycosidic bonds. Rates of cyanogenesis were higher when ruminal inocula were from cattle fed fresh alfalfa or cubed alfalfa hay rather than grain or long hay. Rates of HCN production were slowest using inocula from cattle fed grain; rates for the three glycosides were negligible at the 3 and 6 h postprandial sampling times.(ABSTRACT TRUNCATED AT 250 WORDS)

Amygdalin↗
PubMed1990

Effects of whole cottonseed and live yeast culture on ruminal fermentation and fluid passage rate in steers.

The effects of adding whole cottonseed (WCS) and live yeast culture (YC) to a diet of 60% alfalfa and 40% concentrate on ruminal fermentation and liquid dilution rate in steers were examined in two trials. Twelve ruminally cannulated Hereford steers (approximately 420 kg) were used. Concentrates were 1) a basal grain mix composed of ground corn, ground barley and rice bran, 2) basal mix with 10% WCS, 3) basal mix with 1.6% YC and 4) basal mix with 10% WCS and 1.6% YC. No differences were detected (P greater than .10) in ruminal pH of steers fed WCS or YC in either trial. Ruminal ammonia levels tended to be higher (P greater than .10) in steers fed WCS. Acetate was higher and butyrate was lower in steers receiving 10% WCS (P less than .10) compared with controls. Molar proportions of acetate and butyrate increased while propionate decreased (P less than .05) over time after feeding. Intake and apparent digestibility of dry matter was not influenced by treatments. Whole cottonseed and(or) YC appear to have minimal effects on ruminal fermentation, but they might alter ruminal liquid passage rate with diets containing 60% ground alfalfa and 40% concentrate.

Ammonia↗