Direct pH Measurement of NaCl-Bearing Fluid with an in Situ Sensor at 400°C and 40 Megapascals

The pH of concentrated NaCl-HCl fluids (0.57 mole of NaCl per kilogram of water) has been measured at supercritical conditions of water with a yttria-stabilized zirconia sensor in a titanium flow reactor. At 400°C and 40 megapascals, the in situ pH of the fluids, ranging from 3.3 to 6.2, differs greatly from its original value of 1.9 to 7.6 at ambient conditions. The measurements agree well with theoretical predictions, showing strong associations of HCl° and NaOH° complexes in high-temperature fluids. The pH sensor provides a powerful tool to investigate unambiguously the distribution of species in aqueous fluids at elevated temperatures and pressures.     

如何做好新形势下种子行业财务统计汇总工作

种子行业财务统计工作是现代种业管理中一项十分重要的基础性工作，通过对财务统计数据的收集、汇总和分析，对于全面了解和掌握当前种子行业的发展状况，及时发现和纠正存在的主要问题，并为国家及各级政府部门制定种子产业发展规划提供重要依据。过去种子行业统计工作是建立在计划经济体制下，主要是针对国有种子公司进行的。随着种子市场的放开和种子企业改制的深入，国有种子企业逐渐与行政事业单位脱钩，成为自主经营、自负盈亏的经济实体。这些体制上的变化，不仅给种子管理工作带来了新的内容和问题，而且也给种子行业财务统计工作增加了新的难度和深度。如何适应新的体制，认真做好财务统计工作，并通过这项工作的开展，为企业经营者在宏观上提供及时准确的信息，是种子行业财务统计工作新的研究课题。近年来，围绕这一课题，我们从加强对种子企业的组织领导和监督管理人手，在统计方法、统计手段、业务指导和业务培训等方面都进行了大胆的改革和尝试，卓有成效地开展了新形势下的财务统计工作，取得了明显的成效和收获。     

Early growth and survival of Eucalyptus pellita provenances in a range of tropical environments,compared with E. grandis,E. urophylla and Acacia mangium

Provenance/family trials of Eucalyptus pellita F. Muell were established at three seasonally-dry tropical sites in northern Australia (two in north Queensland and one on Melville Island in the Northern Territory), and at Luasong, a tropical site with year-round high rainfall and humidity in Sabah, Malaysia. After 2–3 years, it was clear that New Guinea provenances outperformed Queensland provenances in their survival, growth and form, and in their crown health, in the humid tropical environment of Luasong. New Guinea provenances were also clearly superior to Queensland provenances in their growth and form at Melville Island, but less clearly so at Cardwell, Queensland. Among Queensland provenances, Helenvale and Kuranda were superior to the more northerly Cape York provenances, Tozers Gap and Lankelly Creek, while there was little difference between the two New Guinea provenances tested, Bupul-Muting (Irian Jaya) and Keru (Papua New Guinea). Significant differences in growth traits, form and survival were demonstrated between families within provenances. In a species/provenance trial at Luasong, E. pellita displayed better growth and survival than tropical provenances of E. grandis and E. urophylla, but was inferior in growth and crown health to Acacia mangium.     

A survey of anthelmintic resistance on ten goat farms in the Manawatu region in 1988

A survey of anthelmintic resistance on ten goat farms was carried out. The criterion for resistance was a faecal egg coynt reduction (FECR) of <90 percent based on arithmetic means of 11 to 19 goats per group. It was found that nine of the ten farms harboured nematodes resistant to oxfendazole when used at Smg/kg although on two of these, the FECR's were 89.2 percent and 89.8 percent. Post treatment larval cultures indicated Haemonchus, Ostertagia and Trichostrongylus were the resistant genera involved. On none of the ten farms was resistance to oral ivermectin at 0.2mg/kg detected.     

Associations between pregnancy outcome and serological response to Neospora caninum among a group of dairy heifers

AIM: To monitor pregnancy in a group of rising 2-year-old dairy heifers on a farm on which abortion due to Neospora caninum was known to occur in previous years.

METHODS: A prospective cohort study group of 164 rising 2-year-old heifers was pregnancy-tested and blood-sampled at 4–5-week intervals throughout gestation. Sera were tested for antibodies to N. caninum at 3–4-month intervals, using an enzyme-linked immunosorbent assay (ELISA). When loss of pregnancy was detected, an N. caninum indirect fluorescent antibody test (IFAT) was conducted retrospectively on stored sera collected the month before abortion, the month abortion was detected, and for the following 2 months, from heifers that aborted. All fetal and placental material detected following abortion was subjected to gross post-mortem and histopathological examination.

RESULTS: Eleven of 18 (61%) heifers that were seropositive and 4/146 (3%) heifers that were seronegative to N. caninum by ELISA, aborted. The relative risk for abortion among ELISApositive heifers was 23.6. Abortion occurred predominantly between Days 120 and 152 gestation among the ELISA-positive heifers and throughout gestation among the ELISA-negative heifers. IFAT titres rose around the time of abortion in most of the heifers that were previously seropositive by ELISA, but dropped rapidly again in post-abortion samples. IFAT titres among 4/6 ELISA-positive heifers that did not abort increased, but later in gestation than the time other heifers aborted. IFAT titres remained negative in heifers that aborted that were ELISAnegative.

CONCLUSIONS: Heifers that were seropositive to N. caninum by ELISA had a much greater risk of abortion than seronegative heifers. Most seropositive heifers showed evidence of a reactivation of infection during pregnancy. High (≥1:2,000) N. caninum IFAT titres also occurred in non-aborting heifers.

CLINICAL RELEVANCE: Culling of replacement heifers seropositive to N. caninum may be a cost-effective strategy for minimising risk of abortion. Pregnancy testing heifers before 5 months gestation may overestimate the number that calve in N. caninum-infected herds, but would assist in documenting the occurrence of abortion. Reliance on a high (>1:2,000) IFAT titre to rule-in N. caninum as a cause of abortion is likely to produce false-positive results.     

Management of gastrointestinal nematode parasites on sheep farms in New Zealand

AIM: To report current farmer opinions and farming practices relating to control of gastrointestinal nematodes and anthelmintic resistance on sheep farms in New Zealand.

METHODS: An interview-based cross-sectional study of grazing management and anthelmintic useage was conducted by veterinarians on 80 randomly selected sheep farms in New Zealand.

RESULTS: Useable data were returned by 74/80 (92%) farmers who participated in the study. However, despite contacting 400 farmers the target sample size of 100 farms was not reached. The results indicated that only 31% of farms had previously tested for drench resistance, that effective quarantine-drenching of imported stock was not always carried out, and that farmers were more likely to integrate cattle than ewes into their grazing management of lambs. Furthermore, the number of drenches given to lambs had changed little in 25 years. The use of faecal egg counting by farmers has increased.

CONCLUSIONS: Dependence on anthelmintics continues to be high on sheep farms in New Zealand. Whilst the number of drench treatments has changed little, there is more widespread use of persistent or long-acting treatments. Farmers need to be encouraged to monitor the resistance status of nematode populations on their farms and use this information to develop strategies aimed at maintaining susceptible alleles within the parasite populations and conserving the efficacy of existing drug families.     

Hammondia heydorni oocysts in the faeces of a greyhound in New Zealand

AIMS: To identify oocysts found in faecal material of a greyhound. METHODS: Polymerase chain reaction (PCR) and DNA sequencing were used to study genomic DNA isolated from oocysts purified from faeces of a greyhound. RESULTS: Database searches with the DNA sequences obtained showed they were derived from Hammondia heydorni. A species-specific PCR was developed to detect H. heydorni DNA. CONCLUSIONS: Light microscopy in conjunction with PCR and DNA sequencing definitively identified the presence of H. heydorni oocysts in faeces of a greyhound. CLINICAL RELEVANCE: This study confirms the presence of H. heydorni in New Zealand and indicates the need to correctly identify similar oocysts from dogs, rather than assume they are Neospora caninum.     

Modelled female sale options demonstrate improved profitability in northern beef herds

Objective To examine the impact of improving the average value of cows sold, the risk of decreasing the number weaned, and total sales on the profitability of northern Australian cattle breeding properties. Design Gather, model and interpret breeder herd performances and production parameters on properties from six beef‐producing regions in northern Australia. Procedure Production parameters, prices, costs and herd structure were entered into a herd simulation model for six northern Australian breeding properties that spay females to enhance their marketing options. After the data were validated by management, alternative management strategies were modelled using current market prices and most likely herd outcomes. Results The model predicted a close relationship between the average sale value of cows, the total herd sales and the gross margin/adult equivalent. Keeping breeders out of the herd to fatten generally improves their sale value, and this can be cost‐effective, despite the lower number of progeny produced and the subsequent reduction in total herd sales. Furthermore, if the price of culled cows exceeds the price of culled heifers, provided there are sufficient replacement pregnant heifers available to maintain the breeder herd nucleus, substantial gains in profitability can be obtained by decreasing the age at which cows are culled from the herd. Conclusion Generalised recommendations on improving reproductive performance are not necessarily the most cost‐effective strategy to improve breeder herd profitability. Judicious use of simulation models is essential to help develop the best turnoff strategies for females and to improve station profitability.     

Apparent lack of efficacy of toltrazuril against Eimeria species affecting brown kiwi (Apteryx mantelli) at a captive rearing facility

AIM: To assess the efficacy of toltrazuril against the Eimeria spp. affecting brown kiwi (Apteryx mantelli).

METHODS: Droppings were collected from three brown kiwi, aged <6 months old, at a captive rearing facility in the North Island of New Zealand, between 22 February and 20 April 2017, on 14 sampling dates. Only droppings (n=30) that were excreted between 03:00 and 07:00, as determined using video surveillance, were included for analysis, reflecting the peak time for shedding of coccidial oocysts for brown kiwi. Oocysts were quantified in each sample and Eimeria species identified on the basis of oocyst morphology. All samples were collected between 2 and 10 days after the birds had been treated with 25?mg/kg toltrazuril.

RESULTS: Eimeria spp. oocysts were identified in 28/30 individual samples and on 14/14 sampling dates. Oocyst counts varied from 0 to 328,080 oocysts per gram (opg), and at least one oocyst count >10,000 opg was measured on 12/14 sampling dates. Three species of Eimeria were observed, with Eimeria apteryxii and E. kiwii most commonly encountered, whereas only one sample contained E. paraurii.

CONCLUSIONS AND CLINICAL RELEVANCE: In the three birds monitored at this research site, there was a high abundance of E. apteryxii and E. kiwii oocysts in droppings despite recent administration of toltrazuril. These results suggest that the populations of Eimeria spp. affecting brown kiwi at this location appear to possess an ability to survive exposure to toltrazuril. Toltrazuril is widely used at captive rearing facilities to limit the effects of coccidiosis in juvenile kiwi. If a lack of efficacy is confirmed, it will be necessary to investigate alternative treatment regimens alongside broader environmental management strategies.