Influence of milk feeding levels and calf housing on subsequent performance of Holstein heifers.

The purpose of this study was to investigate the effects of increased milk feeding levels or social housing during the preweaning stage of Holstein dairy heifers on subsequent weight gain, health, and reproductive parameters over time. A total of 210 heifers were grouped by calving date in groups of 10 and randomly assigned to one of 3 treatments: low-milk individual housing (LMI; 4 L of milk/d), high-milk individual housing (HMI; 8 L of milk/d), or low-milk social housing (LMS; 4 L of milk/d). Data collected included passive transfer status, disease events, weight gain at different time periods, age at first calving, calving intervals, and milk yield over the first 3 lactations. Passive transfer was successful in 189 calves, and, overall, disease events were low in this herd. The average daily gain for heifers in the HMI group (0.79 ± 0.05 kg/d) was significantly higher (F 2, 9 = 4.76) during the preweaning treatment period compared with the other groups (LMI: 0.59 ± 0.05 kg/d; LMS: 0.68 ± 0.04 kg/d). Although treatment groups did not differ with respect to age at first calving, the LMS and HMI heifers calved (22 and 15 d, respectively) earlier than the LMI heifers. Milk yield over 3 lactations was similar among the treatment groups. This suggests that both nutrition and social dynamics can influence performance of preweaned calves. Further investigation is needed to understand the mechanisms driving increased weight gain in socially housed calves.

Calving location preference and changes in lying and exploratory behavior of preparturient dairy cattle with access to pasture.

The objectives of this study were to (1) describe the calving location of dairy cattle given access to a pasture and barn; (2) identify factors associated with calving location; and (3) compare the lying and exploratory behavior of cows in the 24 h before calving and a previous day. Seventy-two Holstein dairy heifers and cows (n = 36 nulliparous and n = 36 primiparous and multiparous combined) were housed in a covered bedded-pack barn (167.4 m2) with free access to 2.1 ha of pasture. The composition of the group was dynamic, because cows were moved in weekly at 19 ± 6 d [mean ± standard deviation (SD)] before their calving date, and were removed immediately after calving. To facilitate data collection, we divided the environment into 9 sections, including the barn (section 1; 167.4 m2), 7 sections of open pasture (sections 2 to 8; 2,402 ± 60 m2), and 1 section of pasture surrounded by natural forage cover (section 9; 3,593 m2). We then collapsed these 9 sections into 3 distinct areas for further analysis: the barn, open pasture, and natural forage cover. Animals were fitted with accelerometers to measure lying time, lying bout duration, lying bouts, and steps for the 24 h before calving (calving day) and a similar 24 h period 4 to 11 d (median = 7) before calving (baseline day). We included parity (nulliparous vs. primiparous and multiparous) and heat stress [no heat stress = temperature-humidity index (THI) ≤68 vs. heat stress = THI >68 and ≤79] in all analyses; we included time of day and group composition as additional factors that may have affected calving location. We determined exploratory behavior using 10 min instantaneous scan sampling collected from video. At each scan, we recorded the section (1 to 9) the cow or heifer was located in, and then calculated the minimum number of sections that could be crossed between successive scans. Of the total sample, 39% calved in the barn, 26% calved in the open pasture, and 35% calved in the area with natural forage cover. Nulliparous heifers and those calving when heat stress was low (THI ≤68) selected the area with natural forage cover more frequently than the barn. On the calving day, cows spent more time lying down with more short bouts of lying, and crossed more sections compared with the baseline day. Steps were affected by an interactive effect of day, parity, and heat stress; nulliparous heifers took more steps on the calving day during conditions of heat stress compared with no heat stress. Results indicate that cows and heifers had different preferences for their environment at calving, and when provided access to pasture, both changed their lying and exploratory behavior on the day of calving compared with a previous day.

Cross-sectional study to estimate the prevalence of enterohaemorrhagic Escherichia coli on hides of market beef cows at harvest.

Cattle hides are an important source of enterohaemorrhagic Escherichia coli (EHEC) carcass contamination at slaughter. Seven EHEC serogroups are adulterants in raw, non-intact beef: EHEC O26, O45, O103, O111, O121, O145 and O157. The objective of this study was to estimate the probability for hide contamination with EHEC among US market beef cows at slaughter and to test the effects of season and geographic region on prevalence of hide contamination. Hides (n = 800) of market cows were swabbed at slaughter immediately after exsanguination, prior to hide removal. Cows were sampled from two geographically distinct beef packing plants during four seasons of 2015. Cattle source was categorized by northern or southern region. Samples were tested for EHEC by a molecular screening assay. The effects of region, season and their interaction on the probability of hide contamination by each EHEC serogroup were tested in separate multilevel multivariable logistic regression models, accounting for the random effect of clustering by plant. Statistical significance was set α = .05. Of 800 total samples, at least one EHEC was detected on 630 (79%) hides. Enterohaemorrhagic E. coli O26 was detected on 129 (16%) of all hides sampled, EHEC O45 on 437 (55%), EHEC O103 on 289 (36%), EHEC O111 on 189 (24%), EHEC O121 on 140 (18%), EHEC O145 on 171 (21%) and EHEC O157 on 89 (11%). Detection of EHEC O26 and EHEC O121 was associated with season. Season and region were associated with detecting EHEC O45 and EHEC O157. Season-by-region interactions were associated with the outcome of detecting EHEC O103, EHEC O111 and EHEC O145. Season, region of origin and the interaction of these factors affect hide contamination of market beef cattle at slaughter by EHEC, and each serogroup responds to these factors uniquely.

A four-season longitudinal study of enterohaemorrhagic Escherichia coli in beef cow-calf herds in Mississippi and Nebraska.

Our objective was to describe the probability of detecting seven serogroups of enterohaemorrhagic Escherichia coli (EHEC-7) of public health importance in faecal samples from beef cow-calf herds and to test for factors associated with their detection. Fresh faecal samples (n = 85) from two Mississippi and two Nebraska herds were collected in each of four seasons. Samples were tested for each EHEC-7 serogroup by a molecular screening assay. Separate management groups within herds were sampled, and group-level factors were recorded. To measure the effects of factors on faecal shedding of EHEC-7, separate multivariable logistic regression models were used, accounting for the random effect of clustering by group within farm. Statistical significance was set α = 0.05. Fifty-nine samples (4.3%) were positive for EHEC O26, and Nebraska samples were more likely to be positive than Mississippi samples (OR = 12.4, 95% CI: 1.1, 139.2). Forty-four samples (3.2%) were positive for EHEC O45. Odds for detection were greater in the summer than all other seasons combined (OR = 4.2, 95% CI: 1.3, 14.0), and odds decreased if a precipitation event occurred (OR = 0.07, 95% CI: 0.006, 0.8). EHEC O103 was detected in 66 samples (4.9%) with increased probability to be detected at increased temperature. EHEC O111 was detected in 71 samples (5.2%), and 43 samples (3.2%) were positive for EHEC O145. Both EHEC O111 and O145 were associated separately with season, with greater probability for detection in the summer. Eighteen (1.3%) and 68 (5.0%) samples were positive for EHEC O121 and EHEC O157, respectively. We failed to detect significant explanatory factors associated with probability to detect EHEC O121 or O157. Factors that vary by time and place, such as precipitation, ambient temperature, region and season, are uniquely associated with the probability to detect EHEC-7 in fresh faeces collected from cow-calf herds.

A randomized controlled trial to evaluate the effects of dietary fibre from distillers grains on enterohemorrhagic Escherichia coli detection from the rectoanal mucosa and hides of feedlot steers.

Feeding high levels (≥40% dry matter) of distillers grains may increase the risk for cattle to carry enterohemorrhagic Escherichia coli (EHEC) O157. The mechanism for the increased risk is not known nor whether non-O157 EHEC are similarly affected. Our objective was to test whether the fibre content or other components of modified distillers grains plus solubles (MDGS) affects the probability for cattle to carry EHEC serogroups of public health importance. A 2 × 2 plus 1 factorial treatment arrangement within a randomized block design was utilized. Within each of four blocks, 25 feedlot pens (n = 8 steers/pen) were assigned randomly to (i) corn-based control diet; (ii) 20% dry matter (DM) MDGS; (iii) 40% DM MDGS; (iv) corn bran added to corn-based diet to match fibre of 20% MDGS or (v) 40% MDGS. Rectoanal mucosa swabs (RAMS) were collected on day (d)0, d35, d70 and d105; hide swabs were collected on the last feeding day. Samples were tested for EHEC by a molecular screening assay. The effects of fibre source and fibre level on EHEC carriage were tested using multilevel logistic regression (generalized linear mixed models; α = 0.05). EHEC O45 RAMS detection was associated with fibre level, source and sampling day. EHEC O103 RAMS detection increased by feeding 40% MDGS but not the corresponding corn bran diet. Hide contamination by EHEC O45 or O103 was less likely in cattle fed MDGS compared to corn bran diets. EHEC O111 RAMS detection decreased by feeding 40% MDGS but not by feeding the corresponding corn bran diet. Detection of EHEC O157 or O145 was not associated with dietary factors. Feeding 40% MDGS increased the probability for carriage of some EHEC serogroups but decreased probability of others, which indicated that EHEC serogroups have different risk factors associated with feeding MDGS and little association with dietary fibre.

Erros de anotações na elaboração de índices de produção em granjas industriais de suínos no Sul do Brasil / The human effect on data collection of birth-related production indices in Brazilian swine industrial farms

Foram realizadas observações em quatro granjas de suinocultura industrial nas 24 horas do dia, registrando-se o número de fetos mumificados, de natimortos, de nascidos vivos e total segundo as observações feitas por funcionários da granja (FUN) e por pesquisadores (AO). Foram também registrados resultados de um número semelhante de anotações das mesmas características no período imediatamente anterior à pesquisa, obtidas dos relatórios das granjas. Verificaram-se diferenças entre as avaliações dos FUN e dos AO quanto aos registros dos mumificados e total de nascidos em todas as granjas (P<0,05). A diferença no número de natimortos ocorreu em três granjas (P<0,05) e de nascidos vivos em apenas uma (P<0,05). Os percentuais máximos de mumificados, de natimortos, de nascidos vivos e total não registrados pelos FUN foram 67,8 por cento, 34,5 por cento, 1,8 por cento e 5,1 por cento, respectivamente. Os percentuais máximos das mesmas características não registrados pelos FUN no período imediatamente anterior à pesquisa foram 70,4 por cento, 82,1 por cento, 10,5 por cento e 16,5 por cento.

A model for clinical evaluation of the effect of antimicrobial agents on carious dentin.

PURPOSE: To evaluate, longitudinally, the effect of a chlorhexidine varnish on the proteolytic activity of dentin caries in vivo. MATERIALS AND METHODS: 20 permanent molars and 8 primary molars with carious lesions in dentin were studied in subjects 18-35 yrs old (n=20), and 5-6 yrs old (n=8) respectively. These lesions were clinically evaluated according to texture and color. Carious dentin specimens were obtained by means of biopsies performed with a #4 carbide bur at the initial visit (TO) before application of a 10% chlorhexidine varnish and 2, 4, 8, and 12 wks thereafter. The dentin biopsies were immersed in Sorensen's buffer, vortexed for 30 s, and mixed with a 1.67 mM solution of n-benzoyl-DL-arginine-naphthylamide (BANA), a substrate for proteolytic enzymes. Samples were incubated overnight at 37 degrees C and color was developed with 0.1% fast garnet. The optical density (OD) of reaction mixtures was recorded photometrically. All teeth were grouped for analysis, as Mann-Whitney tests revealed no statistically significant differences between median values for OD for both age groups. ANOVA was used to compare progressive inhibition of proteolytic activity in dentin caries samples over time. RESULTS: The average proteolytic activity at the dentin substrates (OD) at TO and 2, 4, 8 and 12 wks thereafter were 0.794+/-0.089, 0.741+/-0.071, 0.676+/-0.087, 0.600+/-0.094, and 0.508+/-0.108 respectively. The chlorhexidine varnish mediated a significant inhibition of the proteolytic activity present in dentin caries after 12 wks (P<0.0001). At T0, 100% of the carious lesions examined were characterized as soft upon exploration. After 12 wks, 54% (15/28) of the lesions were partially hardened and 46% (13/28) hardened/nonprogressing. The dentin color was yellow/light brown in 100% of the lesions at baseline, and dark brown/black in 86% (24/28) after 12 wks. CLINICAL SIGNIFICANCE: This study demonstrated that chlorhexidine varnishes arrested active caries in vivo and inhibited the proteolytic activity present in these lesions. These findings strengthen the rationale for including chlorhexidine in the overall treatment strategy for patients with high caries activity.

Unstimulated salivary flow rates of young children.

OBJECTIVE: Studies on salivary flow rates in human beings have mainly been carried out with adults. The purpose of this study was to determine the unstimulated salivary flow rates of children 4 to 7 years old. In addition, the relative contributions of the variables age, gender, race, height, body weight, dentition status, use of prescription medication, and health status (information obtained from parents) to the unstimulated salivary flow rates of children were also studied. STUDY DESIGN: Data were obtained from children (n = 447) at 2 sites in the United States (site 1, southeast Michigan; site 2, northern Michigan) and at 5 sites in Brazil (site 3, Porto Alegre; site 4, São Paulo; site 5, Belém; and sites 6 and 7, sites in Rio de Janeiro). In northern Michigan (site 2) the participants were cognitively or developmentally disabled, or both. In Rio de Janeiro (site 7), a group of 8- to 12-year-olds served as a control group. Saliva samples were collected for 3 minutes between 9 AM and noon in the spring or summer, and the saliva rate was determined gravimetrically. Data were analyzed by analysis of variance, bivariate analysis, and regression analysis. RESULTS: The secretion rates at the 7 sites were (in milliliters per minute) 0.19 +/- 0.15, 0.23 +/- 0.28, 0.34 +/- 0.23, 0.48 +/- 0.37, 0.25 +/- 0.27, 0.37 +/- 0.28, and 0.61 +/- 0.34, respectively. There were significant differences among sites (P <.0001). The older group (site 7) had flow rates that were significantly higher than the flow rates of any other group. In addition, children from Michigan (sites 1 and 2) had significantly lower rates than most groups of children in Brazil. Girls had lower unstimulated salivary flow rates than boys did at all the sites, but the differences were not statistically significant. Race was shown not to affect the flow rates. The use of any prescription medication by children in the previous 3 months was associated with lower salivary flow rates than were found in children not using prescription medication. Children who were in good health and who had no previous medical conditions had higher flow rates--but not significantly so. Higher flow rates occurred in children with mixed dentition than in children with primary dentition, although again the differences were not statistically significant. Regression analysis revealed weight to be of significance in explaining the variability of the unstimulated salivary flow rates at 2 sites, height at 1 site, the use of prescription medication at 2 sites, and age at 1 site. CONCLUSIONS: The unstimulated salivary flow rates in children in the northern United States are comparable with those reported for Japanese children, whereas the flow rates of children in Brazil are comparable with those reported for North American and European adults. In addition, none of the demographic variables/parameters tested contributed consistently to the variability of the unstimulated salivary flow rates in children at the 7 sites assessed in this study.

Medication usage and dental caries outcome-related variables in HIV/AIDS patients.

The purpose of this study was to access current medication usage by HIV/AIDS patients and its effects on dental caries and on unstimulated salivary flow rates. Thirty females and 127 males (mean age = 39.6 +/- 7.4 years), of whom 46% were White/Non-Hispanic, 39% African-American, and 15% Hispanic, were examined and interviewed at the Bering Dental Clinic, Houston, Texas. The mean time in years after seroconversion was 5.4 +/- 4.1. Calibrated examiners performed dental caries examination (DMFS) with dental explorers and bitewing radiographs. Interviews were carried out with pretested questionnaires, and medication usage was assessed by illustrative examples of HIV/AIDS medications. Salivary flow rates were determined gravimetrically (mL/min). Bivariate analysis and analysis of variance (ANOVA) were used to analyze the data. Because there were no race or gender effects on dental caries outcome variables or salivary flow rates, separate logistic regression models for medication usage were generated, which were adjusted for age and CD4+ cell counts. Patients who, currently, were receiving antiretroviral therapy (ART) had a lower occurrence of dental caries than patients not taking these medications. An unexpected finding in the lower caries rate group was a decrease in salivary flow rates, which was a probable oral side effect of ART. It appears from this cross-sectional study that systemic medication for the management of HIV disease has no significant detrimental effect on the dentition.

Tramadol hydrochloride: analgesic efficacy compared with codeine, aspirin with codeine, and placebo after dental extraction.

Tramadol hydrochloride is a novel, centrally acting analgesic with two complementary mechanisms of action: opioid and aminergic. Relative to codeine, tramadol has similar analgesic properties but may have fewer constipating, euphoric, and respiratory depressant effects. A two-center randomized double-blind controlled clinical trial was performed to assess the analgesic efficacy and reported side effects of tramadol 100 mg, tramadol 50 mg, codeine 60 mg, aspirin (ASA) 650 mg with codeine 60 mg, and placebo. Using a third molar extraction pain model, 200 healthy subjects were enrolled in a 6-hour evaluation after a single dose of drug. Of the 200 patients enrolled, seven provided incomplete efficacy data or discontinued prematurely and one was lost to follow-up. Using standard measures of analgesia, including total pain relief score (TOTPAR), maximum pain relief score (MaxPAR), sum of pain intensity difference scores (SPID), peak pain intensity difference (Peak PID), remedication, and global evaluations, all active treatments were found to be numerically superior to placebo. ASA/codeine was found to be statistically superior to placebo for all measures of efficacy. Tramadol 100 mg was statistically superior to placebo for TOTPAR, SPID, and time of remedication, whereas tramadol 50 mg was statistically superior to placebo onlyfor remedication time. Codeine was not found to be statistically superior to placebo for any efficacy measure. A greater TOTPAR response compared with all other active measures was seen for ASA/codeine during the first 3 hours of study. The 6-hour TOTPAR scores for the tramadol groups and ASA/ codeine group were not significantly different. Gastrointestinal side effects (nausea, dysphagia, vomiting) were reported more frequently with tramadol 100 mg, ASA/ codeine, and codeine 60 mg than with placebo.

Preliminary report on the effects of propolis on wound healing in the dental pulp.

The purpose of this investigation was to determine the antimicrobial and healing potential of propolis on direct dental pulp exposures. This study used 25 adult male rats. Pulp exposures were performed and animals were allocated to propolis and calcium hydroxide (Ca(OH)2 groups. Animals were killed on days 5, 7, 10, and 14. The teeth were routinely processed for histological evaluation. Non-parametric tests were employed to analyze the data. No significant differences were found between study groups on the wound healing of the dental pulp. Both substances were comparable in exhibiting normal reorganization of the pulp and no increased vascularity, and were equally efficacious in maintaining a low inflammatory and microbial cell population as well as in stimulating the formation of reparative dentin.

Rabies virus vaccines.

Many years of research and observations on bait uptake, efficacy, behavioural studies of foxes, reduction and elimination of rabies, population dynamics of foxes following oral vaccination, as well as annual exchanges of researchers' experiences, formed the scientific background for field trials extending over many years. These are the most extensive field studies for the testing of a rabies vaccine so far. The use of the techniques and strategies of oral immunisation of foxes against rabies using SAD B19 can eliminate wildlife rabies among foxes and raccoon dogs, as European experience has shown. The disease then also disappears completely in domestic animals and man.

Antigenic characterization of street rabies virus isolates from Nigeria using monoclonal antibodies.

Twenty isolates of street rabies virus were recovered in mouse neutroblastoma cells from 84 rabies suspect brain specimens from Nigeria dogs and a cat. They were characterized with the Tübingen monoclonal antibody panels directed against nucleocapsid and glycoprotein antigens. Antigenic variations were detected both with antinucleocapsid (anti-NC) and antiglycoprotein (anti-GP) monoclonal antibodies (mabs). One isolate reacted positively with anti-NC mab P41 which hitherto has been known to react positively with polar rabies. Another isolate did not react with anti-NC mab 187.5; a reaction normally seen with ERA/SAD strains of rabies virus. With anti-GP mabs it was possible to group the isolates by their area of origin. Isolates from Plateau State were not neutralized by anti-GP mabs ERA 543 and P44.7.2. The isolates studied had glycoprotein antigenic patterns different from the pattern for low egg passage (LEP) Flury strain vaccine virus used in Nigeria for immunization of dogs.

Molecular cloning and complete nucleotide sequence of the attenuated rabies virus SAD B19.

Complementary DNA spanning the entire genome of the attenuated rabies virus strain SAD B19 which is used for oral immunization of foxes in Europe was cloned and sequenced. The viral genome comprises 11,928 nucleotides and encodes the five viral proteins N, NS, M, G, and L. Deduced protein sequences are highly similar to those of the pathogenic PV strain, homologies ranging from 90.6% for the M to 98.6% for the L protein. The five cistrons are separated by intergenic regions of 2, 5, 5, and 24 nucleotides, respectively. The G transcription stop/polyadenylation consensus signal in SAD B19 is destroyed by a deletion of three A residues. The strong conservation of both noncoding and coding nucleotide sequences indicates a high selective pressure on the primary structure of rabies virus genomic RNA.

Identification of fox rabies by a monoclonal antibody directed against nucleocapsid of a street rabies virus.

Hybridomas were prepared by fusion of spleen cells from BALB/c mice immunized with dog rabies isolates from Nigeria with P3x63Ag8 myeloma cells. More than 69 hybridomas secreted antinucleocapsid (antiNC) antibodies when tested with homologous viruses by indirect immunofluorescence. One hybridoma (Z144-88) was found which secreted antiNC antibody that reacted negatively with fox rabies isolates from the Federal Republic of Germany, Switzerland and France and with rabies-related viruses and European bat isolates. It reacted positively with other strains/isolates of rabies virus. It is possible to use this antiNC monoclonal antibody (mab) for the investigation of fox rabies outbreaks in Europe.

Ineffectiveness and comparative pathogenicity of attenuated rabies virus vaccines for the striped skunk (Mephitis mephitis).

Three attenuated rabies virus vaccines (SAD-B19, ERA/BHK-21, AZA 2) were compared for efficacy and safety in the striped skunk (Mephitis mephitis) by the oral and intranasal routes. The SAD-B19 and ERA/BHK-21 vaccines were given orally; all three vaccines were given intranasally. Oral administration of SAD-B19 and ERA/BHK-21 vaccines induced neither seroconversion nor significant protection against rabies challenge. One skunk which consumed a SAD-B19 vaccine-laden bait succumbed to vaccine-induced rabies. Intranasal instillation of the three vaccines resulted in the deaths of two of six (AZA 2), three of six (ERA/BHK-21) and six of six (SAD-B19) skunks.

Oral immunization of foxes against rabies: practical experiences of a field trial in the Federal Republic of Germany.

The development of and the logistics used in campaigns for the oral immunization of foxes against rabies in the Federal Republic of Germany are described. The "Bavarian Model", which is outlined in detail, shows how local hunters were recruited for bait distribution and control measures at practically no cost. Over 10 million baits have been distributed in this way by hundreds of thousands of hunters in the Federal Republic of Germany as well as in the other European countries that participated in this large-scale field trial. As a result of the trial, rabies has been reduced or even eradicated in large parts of the Federal Republic of Germany.