Sperm Pre-Incubation Prior to Insemination Affects the Sex Ratio of Bovine Embryos Produced in vitro

The objective of the present study was to determine whether sperm incubation prior to oocyte insemination in vitro affects the sex ratio of resulting blastocyst. Cumulus–oocyte‐complexes (COCs) collected from slaughterhouse ovaries were matured in vitro and inseminated with frozen‐thawed semen of three proven artificial insemination (AI) bulls pre‐incubated in vitro in Sperm‐Talp for 6 and 24 h. On day‐9 blastocysts were collected and processed for sex determination. More than 80% of blastocyst were successfully sexed. There were no significant differences in cleavage and blastocyst rates using sperm pre‐incubated for 6 h as compared with the 0‐h pre‐incubation control group. The cleavage and blastocyst rates were significantly lower in the 24‐h pre‐incubation group. The male to female ratio, when compared with the theoretical 1 : 1, differed significantly in favour of females among hatched (viable) blastocysts derived from sperm pre‐incubated for 24 h prior to insemination as well as among all blastocytsts in the 6‐h group. Moreover, when the sperm treatment was considered, the sex ratio was affected only among hatched blastocysts in 24‐h pre‐incubation group. It was concluded that prolonged sperm pre‐incubation influences the rate of development and the sex ratio among hatched blastocysts.     

Clinicopathological features of 11 suspected outbreaks of bovine adenovirus infection and development of a real-time quantitative PCR to detect bovine adenovirus type 10

CASE HISTORY: A retrospective study was conducted to investigate 11 outbreaks of presumptive fatal adenovirus infection diagnosed through two New Zealand diagnostic laboratories during 2014 and 2015. Outbreaks occurred in 6–12-month-old Friesian or Friesian cross cattle during autumn, winter and spring. Individual outbreaks were short in duration, with mortality rates ranging from 3/250 to 20/600 (1.2 to 3.3%).

CLINICAL AND PATHOLOGICAL FINDINGS: Clinical signs included severe diarrhoea, depression, recumbency, and death. Post-mortem examination revealed congestion and oedema of the alimentary tract and fluid to haemorrhagic intestinal contents. Histopathological lesions were characterised by congestion and haemorrhage of the alimentary tract mucosa, oedema of the submucosa, and mild interstitial inflammation in the kidneys. Large basophilic intranuclear inclusion bodies were identified in vascular endothelial cells of the alimentary tract in 11/11 cases and of the kidney in 8/9 cases.

MOLECULAR TESTING: A real-time quantitative PCR (qPCR) assay was designed to detect bovine adenovirus type 10 (BAdV-10) using hexon gene sequences available in GenBank. DNA extracted from a field case and confirmed by sequencing was used as a positive control. The qPCR had a reaction efficiency of 101% (R²=0.99) and the limit of detection was <10 DNA copies/reaction. The qPCR detected BAdV-10 in formalin-fixed paraffin-embedded (FFPE) tissue from 10/11 cases. DNA sequencing of PCR products from nine of these cases showed them to be identical to BAdV-10 sequences in GenBank. For the PCR-negative case, the PCR product had a hexon sequence 99% similar to bovine adenovirus Wic isolate Ma20-1, a close relative of BadV-10.

DIAGNOSIS: Bovine adenovirus type 10 was identified in FFPE tissues from cattle with histopathological evidence of adenovirus infection.

CLINICAL RELEVANCE: Bovine adenoviruses, and especially BAdV-10, should be considered in the differential diagnosis for acute enteric disease and death in young cattle. The qPCR detected BAdV-10 from FFPE tissue of cattle with suspected adenoviral infection diagnosed by histopathology. However results should be interpreted in light of clinical and pathological findings due to the possibility of adenovirus shedding by healthy cattle and the presence of pathogenic adenoviruses other than BAdV-10.     

Growth and carbon accumulation in root systems of Pinus taeda and Pinus ponderosa seedlings as affected by varying CO(2), temperature and nitrogen

It has been hypothesized that increasing atmospheric CO(2) concentration enhances accumulation of carbon in fine roots, thereby altering soil carbon dynamics and nutrient cycling. To evaluate possible changes to belowground pools of carbon and nitrogen in response to elevated CO(2), an early and a late successional species of pine (Pinus taeda L. and Pinus ponderosa Dougl. ex Laws, respectively) were grown from seed for 160 days in a 35 or 70 Pa CO(2) partial pressure at low or high temperature (30-year weekly mean and 30-year weekly mean + 5 degrees C) and a soil solution nitrogen concentration of 1 or 5 mM NH(4)NO(3) at the Duke University Phytotron. Seedlings were harvested at monthly intervals and growth parameters of the primary root, secondary root and tap root fractions evaluated. Total root biomass of P. ponderosa showed a positive CO(2) response (105% increase) (P = 0.0001) as a result of significant increases in all root fractions in the elevated CO(2) treatment, but all other main effects and interactions were insignificant. In P. taeda, there were significant interactions between CO(2) and temperature (P = 0.04) and CO(2) and nitrogen (P = 0.04) for total root biomass. An allometric analysis indicated that modulation of the secondary root fraction was the main response of the trees to altered environmental conditions. In P. ponderosa, there was an increase in the secondary root fraction relative to the primary and tap root fractions under conditions of low temperature. In P. taeda, there was a shift in carbon accumulation to the secondary roots relative to the primary roots under low temperature and low nitrogen. Neither species exhibited shifts in carbon accumulation in response to elevated CO(2). We conclude that both species have the potential to increase belowground biomass substantially in response to rising atmospheric CO(2) concentration, and this response is sensitive to temperature and nitrogen in P. taeda. Both species displayed small shifts in belowground carbon accumulation in response to altered temperature and nitrogen that may have substantial ecosystem consequences over time.     

Effects of elevated concentrations of atmospheric CO2 and tropospheric O3 on decomposition of fine roots

Rising atmospheric carbon dioxide (CO2) concentration ([CO2]) could alter terrestrial carbon (C) cycling by affecting plant growth, litter chemistry and decomposition. How the concurrent increase in tropospheric ozone (O3) concentration ([O3]) will interact with rising atmospheric [CO2] to affect C cycling is unknown. A major component of carbon cycling in forests is fine root production, mortality and decomposition. To better understand the effects of elevated [CO2] and [O3] on the dynamics of fine root C, we conducted a combined field and laboratory incubation experiment to monitor decomposition dynamics and changes in fine root litter chemistry. Free-air CO2 enrichment (FACE) technology at the FACTS-II Aspen FACE project in Rhinelander, Wisconsin, elevated [CO2] (535 microl 1-1) and [O3] (53 nl 1-1) in intact stands of pure trembling aspen (Populus tremuloides Michx.) and in mixed stands of trembling aspen plus paper birch (Betula papyrifera Marsh.) and trembling aspen plus sugar maple (Acer saccharum Marsh.). We hypothesized that the trees would react to increased C availability (elevated [CO2]) by increasing allocation to C-based secondary compounds (CBSCs), thereby decreasing rates of decomposition. Because of its lower growth potential, we reasoned this effect would be greatest in the aspen-maple community relative to the aspen and aspen-birch communities. As a result of decreased C availability, we expected elevated [O3] to counteract shifts in C allocation induced by elevated [CO2]. Concentrations of CBSCs were rarely significantly affected by the CO2 and O3 treatments in decomposing fine roots. Rates of microbial respiration and mass loss from fine roots were unaffected by the treatments, although the production of dissolved organic C differed among communities. We conclude that elevated [CO2] and [O3] induce only small changes in fine root chemistry that are insufficient to significantly influence fine root decomposition. If changes in soil C cycling occur in the future, they will most likely be brought about by changes in litter production.     

Branch growth and biomass allocation in Abies amabilis saplings in contrasting light environments

Aboveground biomass allocation, and height and branch growth were studied in saplings of the shade-tolerant conifer, Abies amabilis Dougl. ex Forbes growing in large openings and in the understory of an old-growth forest in western Oregon. The presence of annual overwintering budscale scars was used to infer extension growth histories; annual growth rings in branches and stems were used in combination with extension histories to compute partitioning of new biomass among leaves, branches and stems. Saplings growing in large gaps had conical crowns, whereas understory saplings had umbrella shaped crowns as a result of much greater rates of branch extension than stem extension. Understory saplings grew slowly in height because of low rates of biomass production and low allocation of biomass to stem extension. About 40% of new biomass was allocated to foliage in both groups, but understory saplings allocated more of the remaining growth increment to branches and less to stem than did saplings growing in large gaps. These results differ from the patterns observed in shade-tolerant saplings of tropical forests, where allocation to foliage increases with shading and branch allocation is much lower than observed here. This difference in allocation may reflect mechanical constraints imposed by snow loads on the evergreen A. amabilis crowns, particularly on flat-crowned understory saplings.     

Applications of ultrasonography in the reproductive management of Dux magnus gentis venteris saginati

Dux magnus gentis venteris saginati is considered to be a Scottish delicacy; however, depleting wild stocks have resulted in attempts to farm them. Selective breeding has been successful in modifying behaviour, increasing body length, reducing hair coat and improving fank (litter) size. However, there are still significant problems associated with the terrain in which they are farmed. This article describes the use of ultrasonography in the reproductive management of this species and the introduction of new genetic material in an attempt to address these problems, with the aim of improving welfare and productivity.     

Failure to detect Salmonella species in a population of wild tuatara (Sphenodon punctatus)

AIM: To assess the prevalence of faecal excretion of Salmonella serovars by wild tuatara (Sphenodon punctatus) on Stephens Island, New Zealand. METHODS: One hundred cloacal swabs obtained as part of health-screening for the translocation of adult tuatara from Stephens Island were subjected to general aerobic culture and enrichment, and cultured specifically for Salmonella spp. RESULTS: No Salmonella spp were cultured from any of the cloacal samples, which suggests that, at the 95% confidence interval, the maximum prevalence of tuatara in the island population that were shedding Salmonella spp not detected by our sample size was 1.5%. Mixed bacteria were grown from the 70 cloacal swabs cultured aerobically. A predominant organism was evident in 30 cultures, and these were identified as Hafnia alvei type 1 (n=16) and type 2 (n=7), Corynebacterium spp (n=4), Klebsiella oxytoca (n=2), and Moraxella spp (n=1). CONCLUSIONS: The absence of intestinal carriage of Salmonella spp by the tuatara sampled in this study may indicate either lack of exposure, or an innate resistance to intestinal colonisation in tuatara. The significance of the other bacteria cultured as potential pathogens to the tuatara and as zoonotic risks is also uncertain. Wildlife managers should screen translocated reptiles for Salmonella spp, and thereby avoid exposing wild and managed populations to infection.     

The application of remote-sensing data to monitoring and modelling of soil erosion

This paper gives a brief synthesis of the information obtainable from remote-sensing data and how it can be related to two significant functions of catchment hydrology, namely, the processes of production and transfer. After presenting examples of the type of information that can be derived from remote sensing (characterisation of soil surface by different wavelengths, temporal changes of surface states, incision and geometry of possible water pathways on the surface, etc.), we examine how this information can provide parameters for input into runoff and erosion models. Finally, we assess the progress in assimilating remote-sensing data into deterministic models of storm runoff.