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221.
The current reliance on insecticides in broccoli production systems has resulted in consumer concerns in relation to chemical residues, quality assurance issues and pest control failures. An alternative to conventional production methods has been shown to reduce insecticide requirements, however the economic feasibility of the new system needs to be considered to facilitate adoption by farmers. Therefore, the agronomic and economic performance of an insect pest suppressive broccoli and cereal rye cover crop system was compared to a broccoli strip crop system and conventional practice (broccoli monoculture). The broccoli cover cropping system resulted in fewer leaves, smaller plants and a slightly reduced yield when compared to the other systems. Strip cropping broccoli with potatoes did not convey any agronomic advantages. Gross margin analysis revealed that on a total system basis, a 2.2% yield improvement or a 7% price premium was required to make the cover crop system perform as well as conventional practice. 相似文献
222.
In 40 submissions to the Regional Veterinary Laboratory (RVL) Wagga Wagga from sheep in southern New South Wales from 1981 to 1989, 53 isolates of Yersinia sp were recovered from 45 sheep in 37 flocks. Of 53 isolates, 26 were identified as Y. pseudotuberculosis, 20 as Y. enterocolitica, 5 as Y. intermedia and 2 as Y. frederiksenii. Twelve isolates of Y. pseudotuberculosis tested in the slide agglutination test all belonged to serotype III. The 20 Y. enterocolitica isolates were categorised biochemically as biotype 5 strains and, of 6 isolates serotyped, all belonged to serogroup 2,3. Outbreaks of yersiniosis were most common in late winter and early spring and affected flocks often had experienced a change in husbandry. Infection with Yersinia sp was associated with diarrhoea, illthrift and mortality. At necropsy, congestion and occasionally thickening of the intestinal mucosa were observed in affected sheep. Gastrointestinal nematodiasis and coccidiosis often were concurrent findings. The characteristic histological lesion in sheep infected with Y. pseudotuberculosis was acute segmental suppurative erosive enterocolitis. There were no lesions consistently associated with Y. enterocolitica, Y. intermedia or Y. frederiksenii. 相似文献
223.
Objectives To determine whether a multivariate model could be developed to describe farm factors affecting fertility of dairy herd and to examine the factors that determined better reproductive performance on dairy farms in New South Wales.
Procedure We examined the results of a survey of breeding practices, mating policies, recording systems, timing of mating, heat detection, treatment of metritis and manager demographics of dairy farms using Principal components analysis, logistic regression and the sign test.
Results Eight principal components for heat detection computed using Principal component analyses were included in the multivariate model to reflect primary and secondary heat detection signs used in the breeding decisions of managers. A final model identified three variables: optimum number of days to first service, number of people detecting heats, and age of manager which significantly influenced the risk of being in the high or low reproductive performance groups. A failure to breed at an appropriate time after calving and having more people responsible for heat detection was associated with herds with a prolonged intercalving interval. While the model provided a good fit for the data, it was not highly discriminatory. Examination of 83 management practices affecting fertility using the sign test (P = 0.01) indicated that managers of herds with good reproductive performance employed better management and breeding practices more often than managers of herds with poor reproductive performance.
Conclusions Mating cows sooner after calving and using fewer people to detect oestrus should reduce calving to conception intervals. Veterinarians investigating herd reproductive performance should consider the potential for a number of subtle failures of management to significantly impair fertility rather than limit investigations to a few factors. 相似文献
Procedure We examined the results of a survey of breeding practices, mating policies, recording systems, timing of mating, heat detection, treatment of metritis and manager demographics of dairy farms using Principal components analysis, logistic regression and the sign test.
Results Eight principal components for heat detection computed using Principal component analyses were included in the multivariate model to reflect primary and secondary heat detection signs used in the breeding decisions of managers. A final model identified three variables: optimum number of days to first service, number of people detecting heats, and age of manager which significantly influenced the risk of being in the high or low reproductive performance groups. A failure to breed at an appropriate time after calving and having more people responsible for heat detection was associated with herds with a prolonged intercalving interval. While the model provided a good fit for the data, it was not highly discriminatory. Examination of 83 management practices affecting fertility using the sign test (P = 0.01) indicated that managers of herds with good reproductive performance employed better management and breeding practices more often than managers of herds with poor reproductive performance.
Conclusions Mating cows sooner after calving and using fewer people to detect oestrus should reduce calving to conception intervals. Veterinarians investigating herd reproductive performance should consider the potential for a number of subtle failures of management to significantly impair fertility rather than limit investigations to a few factors. 相似文献
224.
JP MORRIS RM ONG JK O'DWYER JL BARNETT PH HEMSWORTH IJ CLARKE EC JONGMAN 《Australian veterinary journal》1997,75(12):883-886
Objective To examine associations between late event-related cerebral potential amplitudes and behavioural responses to noxious electrical stimulation as an indicator of acute pain in sheep.
Design Analysis of variance for the effects of stimulus intensity on the behaviour and event-related cerebral potential variables.
Procedure Ninety-six brief constant current electrical pulse trains were presented to the front left leg of eight sheep at four intensities (2.5 to 10 mA) in a randomised order. An event-related cerebral potential and a graded flinch response were recorded for each stimulus and the 24 event-related cerebral potentials at each intensity were averaged to produce a mean waveform. Various components of this waveform were analysed and changes in these measures and the sheep's flinch response, as stimulus intensity increased, were determined.
Results Both the flinch response and some event-related cerebral potential components, that is, peak amplitudes 114 {N1}, 187 {P1}, 318 {P2} and 230 {Pm} ms after stimulus onset, were significantly affected as stimulus intensity increased.
Conclusion These corresponding behavioural and event-related cerebral potential changes indicate the usefulness of using changes in the event-related cerebral potential to measure acute pain in sheep. 相似文献
Design Analysis of variance for the effects of stimulus intensity on the behaviour and event-related cerebral potential variables.
Procedure Ninety-six brief constant current electrical pulse trains were presented to the front left leg of eight sheep at four intensities (2.5 to 10 mA) in a randomised order. An event-related cerebral potential and a graded flinch response were recorded for each stimulus and the 24 event-related cerebral potentials at each intensity were averaged to produce a mean waveform. Various components of this waveform were analysed and changes in these measures and the sheep's flinch response, as stimulus intensity increased, were determined.
Results Both the flinch response and some event-related cerebral potential components, that is, peak amplitudes 114 {N1}, 187 {P1}, 318 {P2} and 230 {Pm} ms after stimulus onset, were significantly affected as stimulus intensity increased.
Conclusion These corresponding behavioural and event-related cerebral potential changes indicate the usefulness of using changes in the event-related cerebral potential to measure acute pain in sheep. 相似文献
225.
Rhodococcus equi infection in goats 总被引:1,自引:0,他引:1
226.
227.
Broad WJ 《Science (New York, N.Y.)》1978,202(4373):1164-1165
228.
229.
Garrett M. Broad 《Agriculture and Human Values》2018,35(4):777-789
Effective altruism is a conceptual approach and emerging social movement that uses data-driven reasoning to channel social economy resources toward philanthropic activities. Priority cause areas for effective altruists include global poverty, existential risks to humanity, and animal welfare. Indeed, a significant subset of the movement argues that animal factory farming, in particular, is a problem of great scope, one that is overly neglected and offers the potential for massive reductions in global suffering. This paper explores the philosophical and methodological tenets of these “effective animal advocates,” offering empirical qualitative insight into their motivations and perspectives. The work also considers the implications of the effective altruists’ entrance into the arena of animal advocacy, taking note of how various factions within both the effective altruist and animal protection movements have received their conceptual and practical interventions. The research highlights several potential contributions of the effective animal advocates, as their commitment to evaluate and amplify pragmatic solutions to the problems of animal suffering has the opportunity to shift institutional and consumer behaviors in ways the animal protection movement has struggled to do in the past. At the same time, key issues related to the community’s research rigor and measurability biases, its lack of demographic diversity, and its tendency to valorize corporate-driven technological solutions open it up to criticism from internal and external detractors alike. 相似文献