A Preliminary investigation of the bioenergetics of pregnancy and lactation of Praomys natalensis and Saccostomus campestris

The energy requirements of pregnant, lactating and non-reproductive Praomys natatensis and Saccostomus campestris were studied in metabolism cages and respirometers. Ingestion rate during pregnancy and lactation was not increased significantly in either species. P. natatensis and S. campestris showed non-significant increases in respiratory rate during pregnancy (18% and 55% respectively) but significant increases in oxygen consumption during lactation (79% and 110% respectively). The results highlight the need for studies quantifying lipid and protein flux during pregnancy and lactation, since quantifying energy turnover alone is inadequate and misleading. The energetic costs of reproduction are discussed in relation to previous studies.     

Role of genetically engineered animals in future food production

Genetically engineered (GE) animals are likely to have an important role in the future in meeting the food demand of a burgeoning global population. There have already been many notable achievements using this technology in livestock, poultry and aquatic species. In particular, the use of RNA interference (RNAi) to produce virus‐resistant animals is a rapidly‐developing area of research. However, despite the promise of this technology, very few GE animals have been commercialised. This review aims to provide information so that veterinarians and animal health scientists are better able to participate in the debate on GE animals.     

The prevalence of Mycoplasma ovipneumoniae and Mycoplasma arginini in the respiratory tract of sheep

Abstract

Extract

In an initial study of mycoplasmas of the respiratory tract of New Zealand sheep a number of strains of mycoplasma were recovered and identified as either M. ovipneumoniae or M. arginini (Clarke et al., 1974 Clarke, J. K., Brown, V. G. and Alley, M. R. 1974. Isolation and identification of mycoplasmas from the respiratory tract of sheep in New Zealand. N.Z. vet. J., 22: 117–121. [Taylor &; Francis Online] , [Google Scholar]). Investigations in Australia have produced evidence that M. ovipneumoniae is associated with a proliferative interstitial pneumonia in Queensland sheep (Sullivan et al., 1973 Sullivan, N. D., St. George, T. D. and Horsfall, N. 1973. A proliferative interstitial pneumonia of sheep associated with mycoplasma infection. I. Natural history of the disease in a flock. Aust. vet. J., 49: 57–62.  [Google Scholar]) and for this reason the present survey was undertaken to investigate the prevalence of mycoplasmas in the respiratory tract of sheepin New Zealand.     

Effect of exogenous FSH on ovulation rate in homozygous carriers or noncarriers of the Booroola FecB gene after hypothalamic-pituitary disconnection or after treatment with a GnRH agonist

We have tested the hypothesis "that the ovulation rate in homozygous carriers (BB) and noncarriers (+2) of the Booroola FecB gene would not be different if the plasma concentrations of follicle-stimulating hormone (FSH) in the two genotypes were similar." For this purpose we used two experimental animal models: 1) the hypothalamic-pituitary disconnected (HPD) ovary-intact ewe; and 2) and GnRH agonist (i.e., Deslorelin)-treated ewe. Following HPD or Deslorelin treatment, the animals had low plasma concentrations of gonadotropins and were anovulatory. In both animal models, BB and +2 ewes were treated with exogenous pregnant mares serum gonadotropin (PMSG) and varying doses of FSH to induce preovulatory follicular growth, and human chorionic gonadotropin (hCG) to induce ovulation. HPD or Deslorelin-treated animals administered with pregnant mares serum gonadotropin without FSH followed by human chorionic gonadotropin failed to ovulate. However for both animal models, the proportion of BB and +2 ewes ovulating to various doses of FSH differed such that significantly greater proportions of +2 animals ovulated relative to the BB genotype (P < 0.05). When HPD or Deslorelin-treated BB and +2 ewes were administered identical doses of FSH, the mean ovulation rate and plasma concentrations of FSH in those animals which ovulated was the same in both genotypes. These findings confirm, at least in part, the aforementioned hypothesis. The results also demonstrated that higher ovulation rates were obtained in both genotypes as the FSH dose was increased. Collectively, these findings infer that the higher mean ovulation rate in normal intact BB ewes compared to the +2 genotype is attributable to effects of the FecB gene at the level of ovarian follicular development as well as at the level of pituitary FSH release.     

The Warrumbungle Post‐Fire Recovery Project—raising the profile of soils

The impacts of a wildfire and subsequent rainfall event in 2013 in the Warrumbungle National Park in New South Wales, Australia were examined in a project designed to provide information on post‐fire recovery expectations and options to land managers. A coherent suite of sub‐projects was implemented, including soil mapping, and studies on soil organic carbon (SOC) and nitrogen (N), erosion rates, groundcover recovery and stream responses. It was found that the loss of SOC and N increased with fire severity, with the greatest losses from severely burnt sandstone ridges. Approximately 2.4 million t of SOC and ~74,000 t of N were lost from soil to a depth of 10 cm across the 56,290 ha affected. Soil loss from slopes during the subsequent rainfall event was modelled up to 25 t ha^?1, compared to a long‐term mean annual soil loss of 1.06 t ha^?1 year^?1. Groundcover averages generally increased after the fire until spring 2015, by which time rates of soil loss returned to near pre‐fire levels. Streams were filled with sand to bank full levels after the fire and rainfall. Rainfall events in 2015–2016 shifted creek systems into a major erosive phase, with incision through the post‐fire sandy bedload deposits, an erosive phase likely related to loss of topsoils over much of the catchment. The effectiveness of the research was secured by a close engagement with park managers in issue identification and a communications programme. Management outcomes flowing from the research included installation of erosion control works, redesign of access and monitoring of key mass movement hazard areas.     

Animal abuse and family violence: survey on the recognition of animal abuse by veterinarians in New Zealand and their understanding of the correlation between animal abuse and human violence

AIMS: To establish the incidence, frequency and type of deliberate animal abuse seen in veterinary practice in New Zealand, and ascertain veterinarians' knowledge of human abuse within the families where animal abuse was occurring. To explore attitudes of veterinarians to and knowledge about the correlation between animal abuse and human violence, and their perceived role in dealing with such issues. METHODS: A postal questionnaire was sent to practising veterinarians in New Zealand. It covered demographics, frequency and type of animal abuse cases seen, awareness of violence towards humans, within families where animal abuse was seen, the methods used for managing animal and human abuse, the incidence of psychological abuse of animals, and the attitudes of veterinarians towards and their beliefs about the link between animal abuse and human violence. RESULTS: A total of 383/1,412 (27% response rate) questionnaires with useable data were returned. Within the group of respondents, the sexes were evenly represented; 40% of respondents worked in small-animal practice, 50% in mixed practice and 10% in large-animal practice. Deliberate animal abuse had been seen by 63% of respondents in the last 5 years; 37% of these had seen such cases once a year or less, while 9% had seen abuse cases at least four times a year. Dogs were the species most commonly reported as abused, followed, in numerical order, by cats, cattle and horses. Among respondents who had seen deliberate animal abuse, 16% either knew of (4%) or suspected (12%) human abuse within the families of the abused animals. A clear majority of responding veterinarians agreed with the statement that people who abuse their animals are more likely to abuse their children (77%) or spouse (70%). CONCLUSIONS: The survey indicated that the majority of respondents had seen cases of animal abuse within the previous 5 years, and dogs were the species most often reported abused. Responding veterinarians felt a strong ethical duty to deal with cases of animal abuse, but they were less comfortable about issues of human abuse, even though the awareness of the link between abuse of animals and abuse of humans was relatively high. CLINICAL RELEVANCE: The greater the awareness of animal abuse and its linkage with human abuse, the greater the possibility that veterinarians can contribute in a meaningful way to the reduction of violence in society.     

Virulence markers in Shiga toxin-producing Escherichia coli isolated from cattle.

This study identified potential virulence markers in 93 eae-positive and 179 eae-negative Shiga toxin-producing Escherichia coli (STEC), isolated from a random sampling of healthy cattle in southwestern Ontario. PCR amplification was used to identify genes for enterohemorrhagic E. coli (EHEC)-hemolysin, the EAF plasmid, and bundle-forming pili (Bfp); adherence to HEp-2 cells and to bovine colonocytes, and the fluorescent actin staining (FAS) test were used to characterize interaction of the bacteria with epithelial cells. The EHEC-hemolysin sequences were detected in 98% of eae-positive isolates compared with 34% of eae-negative isolates. All isolates were negative for EAF and bfp sequences. There was 100% correlation between localized adherence (LA) to HEp-2 cells and the FAS test. Forty-eight (52%) of the eae-positive isolates were LA/FAS-positive, whereas none of the 179 eae-negative isolates was positive in either test. Among the eae-negative isolates, 20 (11%) showed diffuse adherence and 5 (2.8%) showed enteroaggregative adherence to HEp-2 cells. Seventy-three percent of the eae-positive isolates adhered to bovine colonocytes, whereas only 26% of 120 eae-negative isolates that were tested adhered. All 13 O157:H7 isolates were positive for eae and EHEC-hemolysin gene sequences, LA/FAS, and adherence to bovine colonocytes. It is concluded that possession of genes for eae and EHEC hemolysin is correlated with the serotype of STEC, that production of EHEC hemolysin was highly correlated with serotypes implicated in human disease, and that none of the potential markers that were examined can be used to predict the potential virulence of an isolate.     

Influence of mapping resolution on assessments of stream and streamside conditions: lessons from coastal Oregon,USA

• 1. Digital hydrographic data are commonly employed in research, planning, and monitoring for freshwater conservation, but hydrographic datasets differ in spatial resolution and accuracy of spatial representation, possibly leading to inaccurate conclusions or unsuitable policies for streams and streamside areas.
• 2. To examine and illustrate the potential for different hydrographic datasets to influence in‐channel and streamside characterizations, a study area in the US Pacific Northwest was chosen because 1:100 000, 1:24 000, and densified 1:24 000 hydrography are available and widely used in research and management for several species of Pacific salmon and trout at risk. The potential was examined for differences among the digital hydrographic datasets in: (1) spatial extent to influence estimated abundances of fish habitat, streamside buffer conditions, and fish distributions; and (2) spatial position to influence estimated streamside buffer conditions and estimated stream gradient.
• 3. The analysis of spatial extent found the total stream length represented by the 1:100 000 hydrography was approximately one half that of 1:24 000 hydrography and only one fifth that of densified 1:24 000 hydrography. The 1:100 000 and 1:24 000 networks differed significantly for 13 out of 18 fish habitat attributes, and the three hydrographic datasets differed significantly for many characteristics in streamside buffers; fish distributions mapped at 1:24 000 added 6–14% of stream length to 1:100 000 distributions. The analysis of spatial position found few differences between the 1:100 000 and 1:24 000 hydrography in streamside buffer characteristics but significant differences in channel gradient.
• 4. Overall, hydrographic datasets differed only slightly in spatial position but differed in spatial extent to the point of representing different populations of streams. If species inhabiting larger streams (greater mean annual discharge) are of interest, then results derived from studies based on 1:100 000 hydrography should prove useful. However, higher‐resolution hydrography can be critical when designing and implementing strategies to protect fish and other aquatic species at risk in smaller streams.

Copyright © 2008 John Wiley & Sons, Ltd.