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PubMed1996

Butylsoyamide increases unsaturation of fatty acids in plasma and milk of lactating dairy cows.

This study was designed to determine whether dietary butylsoyamide increased unsaturation of fatty acids in milk of lactating dairy cows. Nine Holstein cows were fed three diets in a 3 x 3 Latin square design, replicated three times. One diet was a control with no added fat, and the other two diets were supplemented (3.5% of the DM) with either soybean oil or butylsoyamide. Milk yields and DMI were similar for the three diets. Milk fat percentage and FCM were reduced by soybean oil, but not by butylsoyamide. Milk protein yield was reduced when butylsoyamide was fed, and milk fat yield was reduced when soybean oil was fed. The soybean oil supplement disrupted ruminal fermentation, causing total VFA and acetate concentrations to decline; the butylsoyamide supplement had no effect on ruminal VFA. The proportion of linoleic acid in plasma fatty acids was similar with the control (54.3%) and soybean oil (52.0%) diets but was higher with butylsoyamide (59.0%). Linoleic acid concentration in milk fat averaged 3.60, 4.77, and 6.28% for the control, soybean oil, and butylsoyamide diets, respectively. Conversion of soybean oil to butylsoyamide protected unsaturated fatty acids from ruminal biohydrogenation, causing linoleic acid to increase in the plasma and milk of dairy cows.

Acetates↗
PubMed1997

Intake and nutritive value of florigraze rhizoma peanut silage for lactating dairy cows.

Florigraze rhizoma peanut (Arachis glabrata Benth.) is a very persistent, high quality legume that is well adapted to subtropical and tropical environments. This legume was ensiled and compared with corn silage (Zea mays) as a feedstuff for lactating dairy cows. Twelve Holstein cows, including 4 ruminally fistulated cows (mean, 70 days in milk), were used in an experiment with a 4 x 4 Latin square design replicated three times. Diets were formulated to contain 50% concentrate on a dry matter (DM) basis. Dietary treatments were rhizoma peanut silage and corn silage fed at DM ratios of 0:50, 20:30, 35:15, and 50:0. The dry matter intake, digestibilities of DM and crude protein, and production of milk and fat-corrected milk decreased quadratically as the percentage of legume in the diet increased. Nearly all of the decrease occurred when rhizoma peanut silage was the sole forage in the diet. The organic matter digestibility of the two forage types was similar; however, digestion of crude protein in rhizoma peanut silage was only 45% (calculated using simultaneous equations). Ruminal pH increased, and ammonia and total volatile fatty acid concentrations decreased, as the percentage of rhizoma peanut silage in the diet increased. In situ digestion rate constants for DM of rhizoma peanut silage were twice that of corn silage, but extent of DM digestion was greater for corn silage. Passage rates of concentrates and forage were unaffected by dietary treatments. Rhizoma peanut silage can replace 70% of corn silage in diets containing 50% concentrate without affecting dairy cow performance.

Ammonia↗
PubMed1998

Fatty acid composition of milk from Holstein cows fed oleamide or canola oil.

Based on previous in vitro results that showed reduced biohydrogenation of oleamide by ruminal microbes, this study was conducted to determine whether the addition of oleamide to the diets of dairy cows would enhance the C18:1 concentration in milk. Nine first lactation Holstein cows were fed three diets in a 3 x 3 Latin square replicated three times. Each period lasted 3 wk. The total mixed diets consisted of 42% corn silage and 58% concentrate (dry matter basis) with either no added fat (control), 3.5% high oleic canola oil, or 3.5% oleamide. Dry matter intake was reduced when oleamide was added to the diet but not when canola oil was added. Milk yields were the same for cows fed all three diets. Canola oil reduced fat-corrected milk yield and milk fat concentration, but these were not affected by oleamide. Milk protein concentration was lower for cows fed oleamide than for cows fed canola oil. Milk C18:1 averaged 23.16% of total fatty acids for cows fed the control diet and increased to 35.13% when canola oil was fed. Oleamide further increased C18:1 to 48.16% of total fatty acids in milk. All fatty acids with > or = 16 carbon chain length were reduced by oleamide. Oleamide was more effective than was canola oil in this study at increasing the oleic acid content of bovine milk. Oleamide reduced dietary intake when added at 3.5% of the dietary dry matter but still had no effect on milk yield or milk composition.

Animals↗
PubMed1977

The available lysine requirements of 7-9 week old sexed broiler chicks.

The experiments were conducted to determine the available lysine requirement of broiler chicks during the 7-9 week growing period. The chicks were sexed at day old, and the sexes were reared in separate pens in the same facility. Commercial-type broiler rations were fed from day old to 7 weeks of age. At 7 weeks the sexing errors were removed and the pens equalized to 50 birds per pen. The eight dietary treatments were replicated three times per sex. Graded levels of L-lysine-HCL were added to the basal ration to give a stepwise increase of 0.07% lysine per level. The available lysine requirement for female during the 7-9 week period was 0.64% for both growth and feed conversion. When this was expressed as a function of energy, 0.187% available lysine per megacalorie of metabolizable energy (M.E) per kg. of diet was required. The available lysine requirement for males during this period was 0.69 and 0.66% for gain and feed conversion, respectively. Expressed as available lysine per megacalorie of M.E. per kg. of diet, the values would be 0.202 and 0.193%, respectively.

Age Factors↗
PubMed1977

The control and prevention of necrotic enteritis in broilers with zinc bacitracin.

The effectiveness of zinc bacitracin in controlling andpreventing necrotic enteritis was tested by growing broilers in a facility where necrotic enteritis outbreaks had previously occurred. Broiler-crossed chicks were fed a commercial-type broiler diet containing 0 mg./kg., 33 mg./kg., or 55 mg./kg. of zinc bacitracin in the diet. Each treatment was replicated six times. Mortality, weight gain, feed conversion, and pigmentation were measured. The control group had 7.4% mortality due to necrotic enteritis as determined by necropsy of each bird upon death. Zinc bacitracin at 10 grams per ton had two mortalities, or 0.4% mortality due to necrotic enteritis. No mortality due to necrotic enteritis occurred with the higher levels of zinc bacitracin. The addition of zinc bacitracin significantly improved (P less than 0.01) the parameters of weight gain, feed conversion, and pigmentation.

Animals↗
PubMed1989

Ochratoxin A and dietary protein. 1. Effects on body weight, feed conversion, relative organ weight, and mortality in three-week-old broilers.

An experiment with a completely randomized 3 x 4 factorial design was used to study the effects of ochratoxin A (0, 2, and 4 mg/kg) and protein (14, 18, 22, and 26%) in three-wk-old broilers. The diets were based on ground yellow corn and dehulled soybean meal. Four hundred and eighty Hubbard x Hubbard broilers were randomly placed in battery brooders, with 10 birds per pen. Each treatment was replicated four times. Body weight increased with rising levels of protein, and decreased with rising levels of ochratoxin A (OA). The efficiency of feed utilization was improved in broilers fed 22 and 26% protein, compared with broilers fed 14 and 18% protein. The efficiency of feed utilization was lower for the birds fed 4 mg/kg of OA, compared with broilers fed 0 and 2 mg/kg of OA, respectively. Using OA increased the relative weight of the liver, kidney, spleen, pancreas, proventriculus, gizzard, and heart and also significantly decreased the relative weight of the bursa of fabricius. A significant interaction between OA and protein was seen in terms of the relative weight of the liver, pancreas, and gizzard, indicating that the rising protein levels spared the OA effect on those organs. Mortality was highest among the broilers fed 4 mg/kg of OA. Protein regression coefficients (beta's) were positive with respect to 21-day body weight and were negative for the feed:gain ratio and mortality, suggesting that protein provided beneficial effects.

Animal Feed↗
PubMed1990

Impact of L-phenylalanine supplementation on the performance of three-week-old broilers fed diets containing ochratoxin A. 1. Effects on body weight, feed conversion, relative organ weight, and mortality.

An experiment with a completely randomized 2-by-3 factorial design was used to study the effects of ochratoxin A (OA; 0 and 4 mg of OA per kg) and supplemental L-phenylalanine (Phe; .0%, .8%, and 2.4% of Phe) in the diets of 3-wk-old broilers. Diets based on ground yellow corn and dehulled soybean meal were fed from Day 1 to 3 wk of age. A total of 240 male Hubbard-by-Hubbard broilers were randomly placed in battery brooders with 10 birds per pen. Each treatment was replicated 4 times. The parameters measured included mortality, BW, feed conversion, and relative organ weight. Broilers receiving OA weighed less and had poorer feed conversions than birds not receiving OA. For broilers receiving OA, the relative weights (grams of organ weight per 100 g of BW) of the liver, proventriculus, gizzard, and heart increased, while the relative weight of the bursa decreased. Supplemental Phe decreased the relative weight of the liver and increased the relative weight of the gizzard and heart. The regression slopes for Phe at 4 mg of OA per kg of diet were significantly different from 0 for BW, the relative weights of the kidney, spleen, and pancreas and approached significance for mortality (P = .065). In the absence of supplemental Phe, 42.5% of the birds died during the study when the dose level was 4 mg of OA per kg of diet. However, when Phe was supplemented at .8 and 2.4%, only 12.5 and 15.0% of the birds died, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

The use of Saccharomyces cerevisiae to suppress the effects of aflatoxicosis in broiler chicks.

Three hundred and sixty day-old commercial broiler chicks were assigned to a 3 x 2 factorial arrangement of treatments to examine the effects of three levels of Saccharomyces cerevisiae 0, .05, and .1% of feed, and two levels of aflatoxin, 0 and 5 ppm, singly and in combination on aflatoxicosis. Each treatment group was replicated three times. The S. cerevisiae and aflatoxin were incorporated in a standard commercial broiler ration and fed to chicks for 4 wk. Data were collected weekly on body weights, and at the end of the experiment on the relative weights of the liver, proventriculus, pancreas, and heart. Serum concentrations of the albumin, total protein, cholesterol, uric acid, triglycerides, and enzyme activities of alanine transaminase, aspartate aminotransferase, lactase dehydrogenase, and creatine phosphokinase were also evaluated. Results showed that chicks receiving aflatoxin-contaminated feed had suppressed body weight (456 g), which significantly improved (516 g) with the inclusion of .1% S. cerevisiae. The relative weights of liver (3.58%), heart (.916%), and proventriculus (.770%), which increased significantly with the addition of 5 ppm of aflatoxin, were restored to 3.00, .783, and .680%, respectively, with the dietary inclusion of .1% S. cerevisiae. The serum concentrations of albumin and total protein (.66 and 1.62 g/100 mL), which were significantly decreased by aflatoxin, were elevated to .88 and 2.24 g/100 mL, respectively, with the inclusion of .1% S. cerevisiae.(ABSTRACT TRUNCATED AT 250 WORDS)

Aflatoxins↗
PubMed1994

Interactive effects of dietary copper and water copper level on growth, water intake, and plasma and liver copper concentrations of poults.

The interactive effects of dietary Cu and water Cu on poult growth, water intake, whole-blood hemoglobin (Hb), and plasma and liver Cu concentrations were investigated using 232-9-old toms. Poults were randomly assigned to two levels of dietary Cu [Basal (B) and B + 204 mg Cu/kg diet] and to four levels of water Cu (0, 51.5, 103, and 206 mg Cu/kg water) in a 2 x 4 factorial arrangement of treatments. Each treatment was replicated six times. All poults received tap water during Days 1 to 5 followed by the water Cu treatments during Days 6 to 10. Water intake was measured daily and gain and feed intake were determined on Days 5 and 10. Day 1 to 5 gain was reduced (P < .02) in poults fed supplemental dietary Cu. Day 1 to 5 feed intake and gain:feed and Day 6 to 10 gain, feed intake, gain:feed, and water intake were not affected (P > .10) by dietary Cu.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2006

Qa-1b and CD94-NKG2a interaction regulate cytolytic activity of herpes simplex virus-specific memory CD8+ T cells in the latently infected trigeminal ganglia.

After ocular infection, HSV-specific CD8+ T cells migrate to and are specifically retained in the ophthalmic branch of the trigeminal ganglia (TG) even at the time when replicating virus is no longer evident. Virus-specific CD8+ T cells maintain an activation phenotype and secrete IFN-gamma in the latent TG. In this report we demonstrated that activated virus-specific memory CD8+ T cells, although potentially cytolytic, also expressed the CD94-NK cell receptor subfamily G2a inhibitory molecule and were unable to exert cytotoxicity when engaged by Qa-1b expressing targets. Interestingly, many neurons in the latent TG expressed Qa-1b, and blocking of Qa-1b/CD94-NKG2a interaction in an ex vivo TG culture resulted in neuronal cell lysis. The expression of the inhibitory CD94-NKG2a molecule could be induced by TGF-beta1, which was shown to present as a bioactive molecule in the latent TG. Additionally, CD4+ forkhead/winged helix transcription factor 3+ T cells were also determined in the latent TG. Our results demonstrate the operation of a regulatory system in vivo that serves to protect irreplaceable neurons from destruction by the immune system.

Animals↗
PubMed1998

Agglutination behavior of mesophilic starter cultures as a function of proteolysis.

Seven mesophilic starter cultures were grown separately in sterilized skim milk for 8 h at 25 degrees C. At the end of the incubation period, samples were analyzed for agglutination behavior by using microscopic examination. Samples were also assayed for proteolytic activity by the spectrophotometric o-phthaldialdehyde (OPA) and trinitrobenzenesulfonic acid (TNBS) methods. This experiment was replicated three times in a randomized block design. Microscopic examination showed that some cultures existed as single cells, diplococci, or short chains; other cultures tended to form long chains. Short-chain-forming cultures had high proteolytic activities, whereas long-chain-forming cultures had low proteolytic activities as measured by the TNBS and OPA methods. Proteolysis measured by both methods ranked starter cultures in the same order (R2 = 0.82). Low detectability values (obtained by dividing the standard error of the sample estimate for each method by its slope ratio) for OPA and TNBS methods indicated that the two assays do not differ significantly (P > 0.05).

Agglutination↗
PubMed2001

Effects of feed withdrawal and transport on cecal environment and Campylobacter concentrations in a swine surgical model.

The objective of the present study was to evaluate how feed withdrawal and transportation influenced the cecal environment and cecal populations of Campylobacter in swine. Four miniature Yucatan gilts (8.8 kg), naturally infected with Campylobacter jejuni, were surgically implanted with cecal cannulas. The gilts were fasted for 48 h. Samples of cecal contents were collected for 7 days prior to and for 7 days after the fast, and mean values were determined for pH, volatile fatty acids (VFA), and CFU enumeration of C. jejuni. This was replicated three times. In another trial, gilts (full-fed) were transported in a livestock trailer for 4 h and cecal samples were collected before and after transport and analyzed for pH, VFA, and CFU. Following a 48-h fast, cecal pH increased (P < 0.05) by 1 unit; acetic and propionic acids decreased (P < 0.05) by 61% and 71%, respectively; and there was a twofold log10 increase (P < 0.05) in CFU/g cecal content of C. jejuni. Values of pH, VFA, and CFU of C. jejuni did not change in cecal samples from gilts following transportation. These data are important for food safety considerations because feed withdrawal, commonly associated with shipping and slaughter, can increase Campylobacter concentrations in the pig intestinal tract.

Animals↗
PubMed2006

Chlorine resistance of Listeria monocytogenes biofilms and relationship to subtype, cell density, and planktonic cell chlorine resistance.

Strains of Listeria monocytogenes vary in their ability to produce biofilms. This research determined if cell density, planktonic chlorine resistance, or subtype are associated with the resistance of L. monocytogenes biofilms to chlorine. Thirteen strains of L. monocytogenes were selected for this research based on biofilm accumulation on stainless steel and rep-PCR subtyping. These strains were challenged with chlorine to determine the resistance of individual strains of L. monocytogenes. Planktonic cells were exposed to 20 to 80 ppm sodium hypochlorite in 20 ppm increments for 5 min in triplicate per replication, and the experiment was replicated three times. The number of tubes with surviving L. monocytogenes was recorded for each isolate at each level of chlorine. Biofilms of each strain were grown on stainless steel coupons. The biofilms were exposed 60 ppm of sodium hypochlorite. When in planktonic culture, four strains were able to survive exposure to 40 ppm of chlorine, whereas four strains were able to survive 80 ppm of chlorine in at least one of three tubes. The remaining five strains survived exposure to 60 ppm of chlorine. Biofilms of 11 strains survived exposure to 60 ppm of chlorine. No association of biofilm chlorine resistance and planktonic chlorine resistance was observed; however, biofilm chorine resistance was similar for strains of the same subtype. Biofilm cell density was not associated with chlorine resistance. In addition, biofilms that survived chlorine treatment exhibited different biofilm morphologies. These data suggest that chlorine resistance mechanisms of planktonic cells and biofilms differ, with planktonic chlorine resistance being more affected by inducible traits, and biofilm chlorine resistance being more affected by traits not determined in this study.

Biofilms↗
PubMed1999

Parameter recovery for the rating scale model using PARSCALE.

The purpose of the present study was to investigate item and trait parameter recovery for Andrich's rating scale model using the PARSCALE computer program. The four factors upon which the simulated data matrices varied were (a) the distribution of the scale values for the items (skewed or uniform), (b) the number of category response options (4 or 5), (c) the distribution of known trait levels (normal or skewed), and (d) the sample size (60, 125, 250, 500, or 1,000). Each condition was replicated 10 times resulting in 400 data matrices. Accurate item and trait parameter estimates were obtained for all sample sizes examined. As expected, sample size seemed to have little influence on the recovery of trait parameters but did influence item parameter recovery. The distribution of known trait levels did not seriously impact the item parameter recovery. It was concluded that Andrich's rating scale model allows for the use of considerably smaller calibration samples than are typically recommended for other polytomous IRT models.

Attitude↗
PubMed1999

Increased levels of DNA topoisomerases in cultured CHO cells treated with the antitumour drug 5-azacytidine.

Cultured Chinese hamster ovary (CHO) cells were treated with the cytidine analogue 5-azacytidine (5-azaC) which, in good agreement with results previously described from studies carried out in other primary or established mammalian cell lines, resulted in extensive chromosome decondensation and a shift in the time of replication of normally late-replicating heterochromatin to earlier replication. DNA topoisomerases (mainly topo I) have been involved in transcription, and the hypomethylating effect of 5-azaC reportedly results in the expression of silenced genes. Whether such an increase in transcription is paralleled by increased levels of both topo I and topo II, as well as by an enhancement in the topoisomerase activities, has been investigated in this work. The results seem to suggest that both the relative amount of topoisomerases and their activities are enhanced after a protracted treatment with the cytidine analogue over those observed in untreated controls. These observations could be significant for antitumour therapy.

Animals↗
PubMed1999

[Audioscan automatic audiometry: theoretical basis and normative data].

Audioscan automatic audiometry is a high resolution method to explore hearing thresholds in the 125 Hz-16 KHz range offering a resolution of 64 points per octave. This procedure makes it possible to study hearing threshold levels at intermediate frequencies which are not measured by conventional audiometry. As suggested in the literature, it is possible to identify hearing threshold notches, considered indicators of mild or subclinical cochlear pathology. In clinical practice, the use of a new audiometric technique requires affirmation of reliability, sensitivity and replicability in time. It also requires defining standard criteria for use in various otologic pathologies. The present study examined 50 normal hearing subjects with conventional audiometry and Audioscan (Essilor model) measurements. A standard acquisition protocol was followed where three Audioscan measurements were conducted per subject. Subjects with a history of acute otologic pathology and familiarity for genetic deafness were ruled out of the study. Multiple, pairwise correlation analyses of the audiometric and Audioscan responses indicate that: (1) there are no significant differences between threshold levels measured by Audioscan and conventional audiometry; (2) there are no significant variations in the hearing levels measured by three Audioscan retests. Three mean indicators of the threshold level have been defined, expressing Audioscan normality in three different frequency ranges. The data suggest that there are some difficulties in the subjectivity of the Audioscan method and some technical problems regarding the lower octave frequencies and these need to be addressed. The results obtained in this study confirmed reliability of the Audioscan in the mid and high frequencies. The definition of the standard mi criteria makes it easier to interpret the Audioscan measurements from cases presenting various otologic pathologies. Therefore, the plasticity and high detection sensitivity of hearing loss make the automatic Audioscan audiometry a useful clinical tool for diagnostic and/or preventive purposes.

Adult↗
PubMed2001

Moving from concepts to study types approaches to classifying scientific inquiry.

There is no such concept as "the ideal research method". Most study types are understood and taught in a relative vacuum without appreciating their philosophical context. However, to achieve an optimal approach is more a matter of resolving the congruence between research purpose and method. Proper location of research methods within a theoretical framework is therefore important, otherwise the resulting over-simplification will eventually lead to inappropriate use of study types. Designing any type of study encompasses the process of identification, exploration and explanation, and utilizes concepts such as manipulation, sampling, replication and time dimensions. Medical research has borrowed study types both from Epidemiology and Social Sciences and practiced as observational and experimental inquiries, and we offer in the present review a framework within which these various types may be understood.

Algorithms↗
PubMed2002

The use of legume trap crops for control of Striga hermonthica (Del.) Benth. in sorghum (Sorghum bicolor L. Moench) in northern Nigeria.

Two different field trials (one trial on sorghum intercropped with groundnut [Arachis hypogaea L.], and another trial on sorghum intercropped with bambara groundnut [Vigna subterranea L. Verdc.]) were conducted during the 1995 and 1996 rainy seasons at the Teaching and Research Farm of the Department of Crop Science, Faculty of Agriculture, University of Maiduguri, Maiduguri (11 degrees 51' N; 13 degrees 15' E) to evaluate the effect of intercropping resistant and susceptible sorghum varieties with the two legume crops for the control of Striga hermonthica (Del.) Benth, in sorghum. The sorghum varieties used for both trials were ICSV 1002, ICSV 1007 (resistant varieties) and War-warabashi (susceptible). Ex-Dakar variety of groundnut was used for the sorghum-groundnut trial, while a creamed brown eyed local bambara groundnut was used for the sorghum-bambara groundnut trial. There were six treatments with the groundnut trial and nine treatments with the bambara trial and all were laid out in a randomised complete block design (RCBD) replicated four times. In the sorghum-groundnut trial, the results show that the intercropping of sorghum with groundnut significantly reduced Striga infestation up to 50% in sorghum in both years. Both resistant varieties supported significantly fewer number of Striga on sorghum when intercropped with groundnut compared with the sole sown susceptible variety. In both years and the combined analyses of 1995 and 1996 data, however, there was no significant difference in grain yield of sorghum due to the treatments. In the sorghum-bambara groundnut trial, the results show that Striga shoot count at harvest in sole sown ICSV 1007 was significantly lower than the ICSV 1002 variety, while the susceptible variety supported significantly higher Striga shoot count than the resistant varieties in both years and the combined analyses. Alternating stands of sorghum and bambara groundnut within the same row, in general, reduced Striga shoot count in all the varieties with a range of 56%-91% reduction than intercropping with sorghum varieties in alternate rows with bambara groundnut with a range of 45%-96% reduction, or sole sorghum of each variety. This resulted in significantly higher grain yield of ICSV 1002 (1175.0 kg ha-1 in 1995, 814.8 kg ha-1 in 1996, and 994.9 kg ha-1 in the combined data) than ICSV 1007 (892.6 kg ha-1 in 1995, 666.7 kg ha-1 in 1996, and 779.6 kg ha-1 in the combined data) when both were planted in alternate stands in the same row with bambara groundnut. This studies have confirmed the potentials of groundnut and bambara groundnut as trap crops in the management of S. hermonthica in sorghum under a dried environment.

Agriculture↗