Phylogenetic analysis of rumen bacteria by comparative sequence analysis of cloned 16S rRNA genes.

Comparative DNA sequence analysis of 16S rRNA genes (rDNA) was undertaken to further our understanding of the make-up of bacterial communities in the rumen fluid of dairy cattle. Total DNA was extracted from the rumen fluid of 10 cattle fed haylage/corn silage/concentrate rations at two different times. Rumen samples were collected on two separate occasions from five cows each.

Genetic diversity among Canadienne, Brown Swiss, Holstein, and Jersey cattle of Canada based on 15 bovine microsatellite markers.

The genetic diversity among Canadienne, Brown Swiss, Holstein, and Jersey cattle was estimated from relationships determined by genotyping 20 distantly related animals in each breed for 15 microsatellites located on separate chromosomes. The Canadienne, Holstein, and Jersey cattle had an average of six alleles per loci compared with five alleles for Brown Swiss. Furthermore, a number of potentially breed-specific alleles were identified.

Vocal responses of piglets to castration: identifying procedural sources of pain.

The aims of this study were to identify which aspects of castration are painful to piglets, and to determine if less painful methods are available. Previous work has shown that piglets produce more high frequency calls (>1kHz) when castrated than when handled identically but not castrated, or when castrated using a local anesthetic. In Experiment 1, we used 90 piglets to assess the vocal responses to different components of the castration procedure: restraint, washing the ano-genital region, scrotal incision, and pulling/severing of the spermatic cords.

Characterization of a major envelope protein from the rumen anaerobe Selenomonas ruminantium OB268.

Cell envelopes from the Gram-negative staining but phylogenetically Gram-positive rumen anaerobe Selenomonas ruminantium OB268 contained a major 42 kDa heat modifiable protein. A similarly sized protein was present in the envelopes of Selenomonas ruminantium D1 and Selenomonas infelix. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of Triton X-100 extracted cell envelopes from S.

Influence of protein supplements on the secretion of leukaemia inhibitory factor by mitomycin-pretreated Vero cells: possible application to the in vitro production of bovine blastocysts with high cryotolerance.

A co-culture system for bovine embryos using mitomycin-treated Vero cells and serum-supplemented modified synthetic oviduct fluid (mSOF) supports the development of in vitro maturation and fertilization-derived oocytes to hatched blastocysts. In this system, it has been suggested that one contribution made by the co-culture cells to embryo development is production of the cytokine leukaemia inhibitory factor (LIF). However, there are concerns about exposure of early embryos to serum due to its incompatibility with embryo cryosurvival.

Technical note: forms and route of vitamin C supplementation for cows.

The purpose of this study was to compare the effect of multiple oral supplementation of two forms of vitamin C on plasma ascorbic acid concentrations in dairy cows. Vitamin C was administrated at the rate of 40 g/d during a 5-d period. The supplements were vitamin C in the form of a fine powder and vitamin C coated with ethyl cellulose.

Characterization of four endogenous viral genes in semi-congenic lines of meat chickens.

Restriction fragment length polymorphism analyses were used to examine endogenous viral genes (ev genes or ALVE genes) of the avian leukosis viral (ALV) family in semi-congenic lines of meat chickens. The Generation 6 lines examined in this study were semi-congenic in that each contained birds with either zero or with one ALVE gene in hemizygous state plus some solitary long terminal repeat (LTR) elements. Using four restriction enzymes on chicken genomic DNA and two probes, one representing the entire ALV retroviral genome and one with only a small part plus the LTR, four ALVE genes were characterized.

Pharmacokinetic study of 45Ca administered intravenously following intramuscular injection of vitamin D3 or 25-hydroxyvitamin D3 in early weaned lambs.

The objective of this study was to evaluate the pharmacokinetic parameters of 45Ca administered intravenously at a dose of 50 microCi in young lambs. The experiment was performed on 18 female lambs allocated to three treatments. Six animals received intravenous calcium only; six received intramuscularly vitamin D3 8 days prior to the administration of calcium; and six received intramuscularly 25-hydroxyvitamin D3 5 days prior to the administration of calcium.

Evidence for production of a new lantibiotic (butyrivibriocin OR79A) by the ruminal anaerobe Butyrivibrio fibrisolvens OR79: characterization of the structural gene encoding butyrivibriocin OR79A.

The ruminal anaerobe Butyrivibrio fibrisolvens OR79 produces a bacteriocin-like activity demonstrating a very broad spectrum of activity. An inhibitor was isolated from spent culture fluid by a combination of ammonium sulfate and acidic precipitations, reverse-phase chromatography, and high-resolution gel filtration. N-terminal analysis of the isolated inhibitor yielded a 15-amino-acid sequence (G-N/Q-G/P-V-I-L-X-I-X-H-E-X-S-M-N).

Female mate choice and male behaviour in domestic fowl.

The purpose of this study was to use paired choice tests to examine mate selection by female domestic chickens, Gallus gallus domesticus. We examined five behavioural and six morphological traits of 34 pairs of males to determine which male features influenced female mate choice. The frequency of a behavioural display known as wingflapping was the only variable that differed significantly between males that were chosen and males that were not.

Extraction of incurred sulphamethazine in swine tissue by microwave assisted extraction and quantification without clean up by high performance liquid chromatography following derivatization with dimethylaminobenzaldehyde.

A rapid and reliable method using microwave energy is described for the extraction of spiked and incurred (freeze-dried and fresh) sulphamethazine residues from swine tissues/organs (muscle, liver and kidney). Incurred tissues were obtained from an abattoir and freeze-dried pig tissue reference materials were produced as part of a reference material study for the Community Bureau of References, European Communities. The extraction was achieved by irradiating the sample in methanol for 25 s in a household microwave oven, commonly referred to as microwave-assisted extraction (MAE).

Introduction of potential helix-capping residues into an engineered helical protein.

MB-1 is an engineered protein that was designed to incorporate high percentages of four amino acid residues and to fold into a four-alpha-helix bundle motif. Mutations were made in the putative loop I and III regions of this protein with the aim of increasing the stability of the helix ends. Four variants, MB-3, MB-5, MB-11 and MB-13, have replacements intended to promote formation of an 'N-capping box'.

Locus-specific diagnostic tests for endogenous avian leukosis-type viral loci in chickens.

The genome of the chicken, Gallus gallus, contains endogenous proviral elements (ALVE elements or ev genes) that display a high degree of similarity to the Avian Leukosis class of retroviruses. The ALVE proviruses are known to modulate physiological processes of the host birds. Different ALVE elements retain variable portions of the complete, prototype viral genome, and each provirus resides in its own specific location within the host genome.

Predictive modelling of inactivation of Listeria spp. in bovine milk during high-temperature short-time pasteurization.

A linear model was derived to describe the thermal inactivation of Listeria innocua in bovine whole milk in a high-temperature short-time pilot scale pasteurizer. Integrated lethal effect, or pasteurization effect (PE), was obtained by converting times at different temperatures in the various sections of the pasteurizer to the equivalent time at the reference temperature (72 degrees C). PE was then related by a simple linear function to the log10 of the % viable counts with a power transformation of the PE values to improve the linear fit.

Methane output and lactation response in Holstein cattle with monensin or unsaturated fat added to the diet.

We measured effects of continuous vs twice-daily feeding, the addition of unsaturated fat to the diet, and monensin on milk production, milk composition, feed intake, and CO2-methane production in four experiments in a herd of 88 to 109 milking Holsteins. Methane and CO2 production increased with twice-daily feeding, but the CO2:CH4 ratio remained unchanged. Soybean oil did not affect the milkfat percentages, but fatty acid composition was changed.

Synthesis of phosphotyrosine-containing peptides using bis-(2,2,2-trichloro)ethyl groups for phosphate protection.

Suitability of bis-(2,2,2-trichloro)ethyl (Tc) groups for protection of phosphate moiety in Boc-mode synthesis of phosphotyrosine peptides is demonstrated Boc-Tyr(PO3Tc2)-OH and Fmoc-Tyr(PO3Tc2)-OH were prepared by acylating H-Tyr(PO3Tc2)-OH with (Boc)2O and Fmoc-ONSu, respectively. Phosphorus introduction was achieved by phosphorylating Boc-Tyr-OBzl with Tc phosphochloride. The Tc-phosphorus protector was found to be incompatible with the Fmoc group because the conditions of Fmoc removal (piperidine treatment) caused dephosphorylation.

Cell-mediated and humoral immune responses in broiler chickens maintained on diets containing different levels of vitamin A.

Broiler chickens were examined for the effects of low (400 IU/kg), standard (1,500 IU/kg), or high (15,000 IU/kg) dietary vitamin A (VitA) levels on immune responsiveness postimmunization to Newcastle disease virus (NDV). A control pair-fed group (1,500 IU/kg) was included to compensate for the reduced feed intake associated with diet containing the low level of VitA. Interdigital skin reactions to phytohemagglutinin (PHA) and CD4:CD8 T lymphocyte ratios were significantly reduced in chickens fed the low VitA diet, whereas their antibody responses to NDV were significantly increased as compared to birds that consumed the 1,500 to 15,000 VitA diet ad libitum.

Comparison of vitamin C bioavailability after multiple or single oral dosing of different formulations in sheep.

The purpose of this study was to compare the bioavailability of either multiple or single oral supplementation of different formulations of vitamin C and intra-duodenal supplementation of one form of vitamin C in sheep. Formulations used in the study were (1) ascorbic acid fine powder (AA); (2) ascorbic acid coated with ethyl cellulose (EC); (3) Rovimix STAY-C (SC); (4) sodium ascorbate (SA); (5) Rovimix C (RC). The bioavailability of vitamin C formulations was assessed by the changes in plasma ascorbic acid concentrations, area under the curve (AUC) and area under the curve above its basal concentration (AUCabove) values.

Cloning and expression of a chicken alpha-amylase gene.

We have isolated and sequenced a genomic clone for a pancreatic alpha-amylase gene (amy) of the chicken (Gallus gallus). The gene is interrupted by nine introns, spans over 4 kb, and encodes a protein (AMY) of 512 aa that is 83% identical to the human pancreatic alpha-amylase enzyme. Southern blot analysis of chicken DNA revealed two distinct pancreatic amy loci.

A heterogeneous population model for the analysis of bacterial growth kinetics.

A two-compartment, heterogeneous population model (HPM) was derived using the simulation software SB ModelMaker to describe the growth of Listeria monocytogenes in bacteriological media at 5-35 degrees C. The model assumed that, at time t = 0, the inoculum was distributed between two distinct compartments, Non-Growing and Growing, and that growth could be described by four parameters: initial total cell population (N0), final maximum cell population (Nmax), maximum specific growth rate (mu(max)), and initial cell population in the Growing compartment (G0). The model was fitted to the data by optimizing the four parameters, and lag phase duration (lambda) was calculated.

A consensus residue analysis of loop and helix-capping residues in four-alpha-helical-bundle proteins.

A statistical study was performed on a set of proteins which adopt the four-alpha-helical-bundle tertiary motif in order to determine amino acid occurrences at helix-capping and loop positions. Eight X-ray crystal structures from the Brookhaven Protein Data Bank (PDB) were examined and N", N', Ncap, Ccap, C' and C" residues were assigned. In addition, a set of 55 protein sequences for the analogous proteins from different strains and species was taken from the Protein Information Resource and Swiss-Prot databanks.

Effect of nigericin, monensin, and tetronasin on biohydrogenation in continuous flow-through ruminal fermenters.

Four ionophores differing in cation selectivity were compared for their effect on microbial fermentation and biohydrogenation by ruminal bacteria in continuous culture. Monensin and nigericin are monovalent antiporters with selective binding affinities for Na+ and K+, respectively. Tetronasin is a divalent antiporter that binds preferentially with Ca2+ or Mg2+.

Effect of the appetite stimulant cyproheptadine on deoxynivalenol-induced reductions in feed consumption and weight gain in the mouse.

Deoxynivalenol (DON, vomitoxin), a Fusarium mycotoxin, is suspected of inducing its anorectic/feed refusal activity through a serotoninergic (5HT) mechanism, possible via 5HT2-receptors. In this study the efficiency of cyproheptadine (CYP), a serotonin antagonist and known appetite stimulant, to attenuate the adverse effect of DON was investigated in mice. CYP was administered in the feed for two days before animals began receiving the DON, which was also added to the feed.