Estimated and predicted changes in the cat population of Australian households from 1979 to 2005

OBJECTIVE: To estimate and predict changes in the cat population of Australian households from 1979 to 2005. METHOD: Telephone surveys were used to estimate Australia's total household cat population for each year from 1979 to 1999. A simple mathematical model based on population characteristics in 1995 was used to predict future population changes to 2005. Estimates and predictions for 1996 to 1999 were compared to validate the model. RESULTS: Australia's household cat population increased steadily from 2.23 million in 1979 to peak at 3.24 million in 1988. Since then it has steadily declined to 2.60 million in 1999. The population size predicted from the mathematical model was similar to that from surveys for the years 1996 to 1999. It is predicted that the population will continue to decline to approximately 2.19 million in 2005. The proportion of Australian households owning cats fell from 31.1% in 1994 to 25.8% in 1999, while the average number of cats per cat-owning household remained relatively constant at 1.47. CONCLUSIONS: Australia's household cat population is decreasing, falling by 19% between 1988, when it reached its peak, and 1999. This contrasts with the US where the population increased by 13.9% over the same period. The decline in Australia appears to be due to a decrease in the total number of cat-owning households rather than the number of cats per cat-owning household. It is likely that this trend will continue unless there is a change in household pet ownership preferences in the meantime.     

Effect of Oil Overlay on Inhibition Potential of Roscovitine in Sheep Cumulus‐Oocyte Complexes

Inhibitors of cyclin‐dependent kinases, as roscovitine, have been used to prevent the spontaneous resumption of meiosis in vitro and to improve the oocyte developmental competence. In this study, the interference of oil overlay on the reversible arrest capacity of roscovitine in sheep oocytes as well as its effects on cumulus expansion was evaluated. For this, cumulus‐oocyte complexes (COCs) were cultured for 20 h in TCM 199 with 10% foetal bovine serum (Control) containing 75 μm roscovitine (Rosco). Subsequently, they were in vitro matured (IVM) for further 18 h in inhibitor‐free medium with LH and FSH. The culture was performed in Petri dishes under mineral oil (+) or in 96 well plates without oil overlay (?) at 38.5°C and 5% CO₂. At 20 and 38 h, the cumulus expansion and nuclear maturation were evaluated under stereomicroscope and by Hoechst 33342 staining, respectively. No group presented cumulus expansion at 20 h. After additional culture with gonadotrophins, a significant rate of COCs from both Control groups (+/?) exhibited total expansion while in both Rosco groups (+/?) the partial expansion prevailed. Among the oocytes treated with roscovitine, 65.2% were kept at GV in the absence of oil overlay while 40.6% of them reached MII under oil cover (p < 0.05). This meiotic arrest was reversible, and proper meiosis progression also occurred in the Control groups (+/?). So, the culture system without oil overlay improved the meiotic inhibition promoted by roscovitine without affecting the cumulus expansion rate or the subsequent meiosis progression.     

Effect of Leptin on In Vivo Goat Embryo Production

The aim of this study was to evaluate the effect of leptin administration during superovulation on in vivo goat embryo production. Ten mature does were superovulated with 133 mg follicle‐stimulating hormone (FSH) i.m. in six descending doses at 12‐h intervals. The goats received 4.8 μg/kg human recombinant leptin s.c. (leptin group, n = 5) or phosphate‐buffered saline (PBS) (control group, n = 5) with the first and second FSH doses. The does were mated and subjected to embryo collection by transcervical technique 6 days later. The total number of cells per embryo and the number of cells with fragmented DNA were assessed in selected blastocysts by combining Hoechst 33342 and terminal dUTP nick‐end labelling (TUNEL) staining. Plasma concentrations of oestradiol (E₂) and progesterone (P₄) were determined by electrochemiluminescence from the day of FSH treatment, on the day of superovulatory oestrus and on the day before embryo collection. Compared with the control group, the does that received leptin had a higher number of transferable embryos (p < 0.005), fewer embryos classified as degenerated (p < 0.001) and fewer TUNEL‐positive cells/blastocyst (p < 0.001). The number of transferable embryos was positively correlated with E₂ concentrations on day of oestrus (r = 0.562; p < 0.01) and P₄ concentrations on the day of embryo collection (r = 0.912; p < 0.001). We concluded that in vivo leptin administration during FSH treatment improved embryo quality and affected ovarian steroidogenesis in superovulated goats.     

Gonadotropin‐induced Puberty Does Not Impair Reproductive Performance of Gilts over Three Parities

The aim of this study was to evaluate the reproductive performance of three parities of gilts treated or not treated with gonadotropin to induce puberty. Sixty gilts received 600 IU of equine chorionic gonadotropin (eCG) followed by 2.5 mg of porcine luteinizing hormone (LH) 72 h later. Fifty‐nine other gilts were exposed only to a mature boar for 15 min twice daily. Artificial insemination (AI) was performed at 0, 12 and 24 h after the detection of oestrus, and gestation was confirmed by ultrasound after 35 days. Sows were inseminated at the first post‐weaning oestrus. The total numbers of piglets born, piglets born alive, stillborn, mummified foetuses, as well as pregnancy and farrowing rates were evaluated for each of the three parities. Culling rates, farrowing intervals and weaning‐to‐oestrous intervals (WEI) were also analysed. Mean age at puberty and oestrous manifestation were not significantly different between treatments (p = 0.0639; 179.20 ± 17.52 compared with 173.96 ± 16.94, 91.66% compared with 94.92%) across the experimental period. However, females that underwent puberty induction showed modest increases both in the number of total pigs born and in the number of piglets born alive. In conclusion, puberty induction through exogenous gonadotropin administration in field conditions did not induce a more concentrated first oestrous manifestation, but trended to a modest increase in the number of pigs born alive in the first parity and a reduced culling rate during the first gestation.     

Use of electrospray mass spectrometry for mass determination of grape (Vitis vinifera) juice pathogenesis-related proteins: a potential tool for varietal differentiation

Methods based on liquid chromatography-mass spectrometry (LC-MS) and protein trap mass spectrometry (trap-MS) were developed to determine the complement of pathogenesis-related (PR) proteins in grape juice. Trap-MS was superior to LC-MS in terms of simplicity, rapidity, and sensitivity. Proteins with a wide range of masses (13--33 kDa) were found in the juices of 19 different varieties of grape (Vitis vinifera) and were identified as mostly PR-5 type (thaumatin-like) and PR-3 type (chitinases) proteins. Although the PR proteins in juices of grapes are highly conserved, small consistent differences in molecular masses were noted when otherwise identical proteins were compared from different varieties. These differences persisted through different harvest years and in fruits grown in different Australian locations. With the definition of four different masses for PR-5 proteins (range = 21,239--21,272 Da) and nine different masses of PR-3 proteins (range = 25,330--25,631 Da) and using statistical analysis, the methods developed could be used for varietal differentiation of grapes grown in several South Australian locations on the basis of the PR protein composition of the juice. It remains to be seen whether this technology can be extended to grapes grown worldwide and to wine and other fruit-derived products to assist with label integrity to the benefit of consumers.     

Contagious ecthyma in the live sheep export industry

Objective: To investigate control options for contagious ecthyma (scabby mouth) in Australian sheep exported live to the Middle East.
Design: Prevalence, vaccination and modelling studies.
Procedure: One hundred and forty weaner sheep (less than 1 year old) on each of 106 farms in Western Australia (WA) and 18 farm groups of adult wethers received at a WA commercial feedlot were examined for lesions of scabby mouth. Sheep on a total of 26 farms in 3 States were divided into treatment and control groups for the vaccination study. A simple deterministic compartmental model was developed to establish which parameters had the greater effect on disease prevalence.
Results: The proportion of farms with evidence of scabby mouth in weaner sheep was 23.6% and, on those farms with the disease, the overall prevalence was 6.1%. At the feedlot, 4 out of 18 farm groups had 5 or more sheep with lesions on arrival. The overall prevalence in the 4 diseased groups was 5.2%. Sheep vaccinated on farm before trucking to the feed-lot had a lower prevalence of scabby mouth at the end of simulated shipping than controls. The main determinant of scabby mouth prevalence was the proportion of sheep immune to the disease.
Conclusion: A program of vaccination for scabby mouth will reduce the prevalence of disease during live export. However, using current technology it is not possible to deliver shipments of sheep to the Middle East that are guaranteed completely free of scabby mouth.     

An investigation of 11 outbreaks of foot-and-mouth disease in villages in northern Thailand

The results of investigations of 11 outbreaks of foot-and-mouth disease in villages in northern Thailand are described. The causative virus was Asia in one in seven outbreaks, Type O in two outbreaks and unknown in two outbreaks. The most probable sources of the outbreaks were co-mingling of cattle and/or buffalo with livestock from an infected neighbouring village (four) and recent introductions of infected cattle from a public livestock market (two) while the probable source could not be determined in five outbreaks. Attack rates in cattle and buffalo ranged from 0.28% to 50.9% but no pigs became sick during any of the outbreaks. Most outbreaks lasted 4 weeks or less. Adult cattle and buffalo were at higher risk of becoming a case when compared with work cattle. Beef cattle were at higher risk than buffalo and adult cattle and buffalo were at higher risk than calves less than 1 year of age. There was significant clustering of cases within households. Serological investigations indicated that many unaffected animals were probably not exposed to virus during the outbreaks. We concluded that close contact between animals was the main method of spread and that differences in attack rates between animal classes reflected differences in animal management. We further concluded that simple quarantine of early cases during outbreaks is likely to be effective in reducing spread within and between villages.     

Effect of dairy slurry application on soil compaction and corn (Zea mays L.) yield in Southern Wisconsin

As stocking rates on Wisconsin dairy farms continue to increase, one possible nutrient management solution is to haul slurry to nearby grain farmer's fields. Although the nutrient and soil building benefits of manure are well known, many grain farmers are hesitant to apply manure on their fields due to potential soil compaction. Studies were initiated to evaluate the effects of tanker-applied slurry on soil compaction and corn (Zea mays L.) yield. An on-station trial was established to address the issues of compaction caused by manure tankers, repeated traffic associated with field headlands, and the possible ameliorating effect of manure itself on corn yield. In addition, 15 replicated on-farm trials were established to evaluate the impact of single pass manure applications on soil compaction and yield. These predominately fall applications were conducted when the host farmer felt that the soil would support tanker traffic. Due to its portability and instrument sensitivity, compactness was evaluated with a data-logging hand held penetrometer.Results from the on-station trial indicate that multiple passes did increase compactness above single-pass traffic and the check. The slurry itself did not attenuate the effect of traffic on soil compaction, nor on yield. Despite yield reductions estimated from in-track samples in both years of 6% (one-pass traffic) and 22% (six-pass traffic) in this study, whole plot corn yields were not reduced due to compaction. The on-farm trials indicated that manure application technique does affect compaction patterns; with broadcast application resulting in less area trafficked by the tanker than injection application, and therefore less area compacted. The narrower gauge truck tires used at some sites led to significantly higher penetrometer readings compared to the control, but this was not the case at sites with wider tractor tires. As in the on-station work, although compaction led to higher penetrometer readings, whole plot corn yields in compacted plots were not adversely affected compared to the control. These results suggest that, in the first year after slurry application, on predominantly prairie derived soils; well-timed applications of dairy slurry do not cause extensive soil compaction nor a reduction in corn yields. This study did not look at the potential residual effects that may positively (>soil organic matter) or negatively (residual soil compaction) impact subsequent crops.