Protective effects against abortion and fetal infection following exposure to bovine viral diarrhea virus and bovine herpesvirus 1 during pregnancy in beef heifers that received two doses of a multivalent modified-live virus vaccine prior to breeding

Objective-To determine whether administration of 2 doses of a multivalent, modified-live virus vaccine prior to breeding of heifers would provide protection against abortion and fetal infection following exposure of pregnant heifers to cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV) and cattle with acute bovine herpesvirus 1 (BHV1) infection. Design-Randomized controlled clinical trial. Animals-33 crossbred beef heifers, 3 steers, 6 bulls, and 25 calves. Procedures-20 of 22 vaccinated and 10 of 11 unvaccinated heifers became pregnant and were commingled with 3 steers PI with BVDV type 1a, 1b, or 2 for 56 days beginning 102 days after the second vaccination (administered 30 days after the first vaccination). Eighty days following removal of BVDV-PI steers, heifers were commingled with 3 bulls with acute BHV1 infection for 14 days. Results-After BVDV exposure, 1 fetus (not evaluated) was aborted by a vaccinated heifer; BVDV was detected in 0 of 19 calves from vaccinated heifers and in all 4 fetuses (aborted after BHV1 exposure) and 6 calves from unvaccinated heifers. Bovine herpesvirus 1 was not detected in any fetus or calf and associated fetal membranes in either treatment group. Vaccinated heifers had longer gestation periods and calves with greater birth weights, weaning weights, average daily gains, and market value at weaning, compared with those for calves born to unvaccinated heifers. Conclusions and Clinical Relevance-Prebreeding administration of a modified-live virus vaccine to heifers resulted in fewer abortions and BVDV-PI offspring and improved growth and increased market value of weaned calves.     

Brucellosis associated with stillbirth in a bottlenose dolphin in Australia

A captive adult female bottlenose dolphin presented with stillbirth. The placenta appeared oedematous. No other gross lesions were evident in the placenta or the stillborn calf. Histopathology revealed mild multifocal placentitis and foetal encephalitis. Brucella sp. was isolated from lung, liver, spleen and kidney. Sequence and phylogenetic analysis demonstrated this organism to be most similar to Brucella ceti sequence type (ST) 27. Brucella sp. DNA was detected in formalin-fixed paraffin-embedded placenta and brain by real-time PCR using primers targeting the IS711 gene. Immunohistochemical staining revealed Brucella sp. antigen in placental inflammation. This is the first report of isolation of Brucella sp. from a marine mammal in the Southern Hemisphere and the first report of marine Brucella-associated disease in Australia.     

Influence of Precipitation on Plant Production at Different Topographic Positions in the Nebraska Sandhills

Several studies have evaluated the spatial distribution of cool- and warm-season grasses across different topographic positions in the Nebraska Sandhills, but limited research has explored topographic differences in total plant production or production of plant functional groups in relation to variable amounts of precipitation. This study evaluated how spring and growing season precipitation influenced plant production at four topographic positions common in the eastern Nebraska Sandhills. Plant production data were collected from annually moved grazing exclosures in mid-June (peak cool-season grass production) and mid-August (peak warm-season grass production) during a 17-yr period from 2001 to 2017. Total plant production and precipitation use efficiency were 35 ? 58% greater on interdune positions, and precipitation marginal response for total plant production was more sensitive to increases in spring and growing season precipitation on interdune compared with dune positions in both mid-June and mid-August. The greater precipitation marginal response of total plant production on interdune positions was driven primarily by greater increases in cool-season grass production with increasing spring or growing season precipitation. Warm-season grass precipitation marginal response was not different among the topographic positions, but production was 23 ? 70% greater on interdune compared with dune topographic positions in mid-August. When differences in the amount of each topographic position at the study location were accounted for, growing season precipitation explained 49% of the variation for total plant production in mid-August, but spring precipitation only explained 23% of the variation for total plant production in mid-June. Because of the differential response of plant production at dune and interdune positions, incorporating the relative amount of each topographic position into estimates of plant production at the pasture or ranch scale will provide better information for adjusting stocking rates to more accurately match animal demand with forage availability.     

Typing of Brachyspira spp. from rodents, pigs and chickens on Swedish farms

Rhodococcus equi is a soil borne bacterium that causes severe morbidity and death in young foals. The economic costs of the disease include loss of life, treatment expenses, veterinary monitoring expenses and, perhaps most importantly, potential reduction in future athletic performance in horses that suffer severe lung abscessations caused by R. equi. Current standard of care for pneumonia caused by R. equi is treatment with a macrolide antimicrobial and rifampicin. However, the hallmark of pneumonia caused by R. equi is severe formation of pyogranulomas and a walling off effect that can prevent systemic antibiotics from reaching antimicrobial concentrations in lung tissues. It is hypothesized that streptolysin O (SLO) used as an adjunct therapy with antibiotics will reduce the duration and severity of disease caused by R. equi pneumonia compared to antibiotic therapy alone. Addition of SLO to the antibiotic enhanced clinical responses compared to the other groups, including the antibiotic alone group. Of particular significance were lower bacterial counts in the lungs and longer survival time in those foals treated with SLO and antibiotics.     

Molecular characterization of equine rotaviruses circulating in Argentinean foals during a 17-year surveillance period (1992-2008)

P[12]G3 and P[12]G14 equine rotaviruses (ERVs) are epidemiologically important in horses. In Argentina, the prevalent ERV strains have been historically P[12]G3. The aim of this study was the detection and characterization of ERV strains circulating in foals in Argentina during a 17-year study (1992-2008). Additionally, the gene sequences of VP7, VP4 and NSP4 encoding genes of representative Argentinean ERV strains were determined and phylogenetic analyses were performed to elucidate the evolutionary relationships of the ERV strains in Argentina. ERVs were detected in 165 (21%) out of 771 diarrheic stool samples, which corresponded to 45 (39%) of 116 outbreaks from the surveyed thoroughbred horse farms. From the positive cases, 51% (n=23) were G3, 33% (n=15) were G14, 4% (n=2) represented a G3+G14 mixed infection and 11% (n=5) of the cases could not be characterized. G3 ERV was detected during the entire period, while G14 ERV was first detected in 2000 and increased its incidence specially in 2006 and 2007. All the analyzed strains belonged to the VP4 P[12] genotype, except for one G3 case which belonged to the P[3] genotype, constituting the first report of a P[3]G3 ERV strain. Phylogenetic analysis of VP7 protein revealed that the G3 Argentinean ERV strains clustered with ERVs from Ireland, while the G14 Argentinean ERV strains formed a distinct cluster within the G14 genotype. The VP4 of the P[12] ERV strains clustered with P[12] strains from Ireland and France. The NSP4 of the Argentinean ERV strains clustered with the NSP4 genotype E12, along with those of guanaco and bovine strains from Argentina, suggesting the a close evolutionary relationship among these Argentinean strains. The results of this study showed changes in the incidence of G3 and G14 during the studied period. The increase in the frequency of G14 ERV, not included in the vaccine, in the second half of the period, may have implications for vaccine design.     

The effect of glycerol inclusion on broiler performance and nutrient digestibility

1. Crude glycerol from biodiesel production was offered ad libitum to broiler chickens in a 21-d feeding and digestibility trial. The study was designed as a 3*2?+?1 factorial design with 3 concentrations (33, 67, 100?g/kg) of glycerol from 2 sources, A and B (PRS Environmental Ltd and John Thompson and Sons Ltd) and a control diet. The diets were formulated to contain apparent metabolisable energy (AME) of 12·95?MJ/kg (assuming 14·6?MJ/kg for glycerol).

2. No significant interactions occurred, so only the main effects were discussed. At 7–14?d, feed conversion ratio (FCR) showed a significant linear response with increased glycerol inclusion. However quadratic responses on FCR were observed for the 21–28?d period and 7–28?d.

3. Glycerol digestibility was significantly greater with birds offered the 67?g/kg and 100?g/kg glycerol-based diets in contrast to the digestibility of 33?g/kg glycerol-based diets.

4. Glycerol inclusion level also had an effect on AME, which increased linearly with increasing glycerol inclusion. Birds offered the diets containing glycerol also required less energy per unit gain in contrast to birds offered the control diet.

5. When examining the effect of source of glycerol, source A glycerol resulted in the highest AME (15·20 vs. 14·72?MJ/kg). There was no significant effect of glycerol source on the other performance parameters.

6. Glycerol digestibility was significantly greater with glycerol from source B (John Thompson and Sons, Ltd) with a mean value of 0·848 in contrast to source A (PRS Environmental), which had a somewhat lower mean glycerol digestibility of 0·757.

7. In conclusion, glycerol source did not affect performance and increasing level of glycerol improved FCR, with 67?g/kg inclusion resulting in the most efficient conversion of feed to gain without any negative effects upon nutrient digestibility.