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11.
Abstract

AIM: To determine what, if any, changes have taken place in the optimum time, for undertaking faecal egg count reduction tests (FECRT) in sheep in New Zealand.

METHODS: A comparison was made between the numbers and types of nematode genera adequately represented for testing purposes (faecal nematode egg count (FEC) of >50 epg) in initial FECRT case submissions to a veterinary laboratory in New Zealand, during two 4-year periods, in 1992–1995 and 2006–2009.

RESULTS: Although there were some minor differences between them, the seasonal patterns of occurrence remained basically the same for all parasite genera in both datasets, with their individual peak periods of representation occurring during February to May in all instances. Not surprisingly, this period of maximum seasonal occurrence for each parasite genus also coincided with those months of the year when the greatest numbers of worm genera were adequately represented for faecal nematode egg count reduction (FECR) testing.

CONCLUSIONS: The results of this study indicate that the optimum time for conducting FECRT in sheep in New Zealand continues to be during the late summer-autumn months of February to May. However, they also reaffirmed that even during this optimal period there are still likely to be many occasions when relatively few nematode genera may be sufficiently well represented for satisfactory FECR testing. Accordingly, veterinary practitioners ought to be aware that, in order to obtain a complete picture of the resistance status of all worm genera on a particular property, such testing may need to be carried out on more than one occasion.  相似文献   
12.
Abstract

Extract

During the past two decades intestinal absorptive and secretory functions and the intestinal flora have been significantly clarified. Important concepts of intestinal dysfunction have emerged which have proved of immense clinical value(32) Moon, H. W. 1974. Pathogenesis of Enteric Diseases Caused by Escherichia coli. Adv. Vet. Sci. Comp. Med, 18: 179211. [PubMed] [Google Scholar] (39) Phillips, S. F. 1972. Diarrhoea: A Current View of the Pathophysiology. Gastroenterology, 63: 495518.  [Google Scholar] (46) Smith, H. W. 1965. Observations on the Flora of the Alimentary Tract of Animals and Factors Affecting its Composition. J. Pathol, 89: 95122.  [Google Scholar] (47) Smith, H. W. 1971. The Bacteriology of the Alimentary Tract of Domestic Animals Suffering from E. coli Infection. Ann. N. Y. Acad Set, 176: 110125.  [Google Scholar] (51) Soergel, K. H. 1973. New Concepts of Intestinal Function. Hepatogaslroenterol, 20: 351358.  [Google Scholar]. Despite this, the medical and economic consequences of diarrhoea continue to beset the cattle industry(1) Barnum, D. A., Glantz, P. J. and Moon, H. W. 1967. Colibacillosis. CIRVeterinary Monograph Series/Two, : 544.  [Google Scholar] (18) Hubbert, W. T. 1974. Factors Affecting Survival of the Bovine Fetus and Neonate. Theriogenology, 1: 1534.  [Google Scholar] (30) Marsh, H. 1968. Prenatal and Postnatal Mortality in Cattle. National Academy of Science. Pub. No. 1685,, : 16.  [Google Scholar] (56) Vollmar, R. E. 1974. Diarrhoea Control in a Dairy Operation. Mod Vet. Pract., 55: 509512.  [Google Scholar] (57) White, R. G. Scours-The Calf Killer. Presented at the California Livestock Symposium. An. Nut. Health, pp.1418.  [Google Scholar]. Diarrhoeal disease of the calf occurs at a time of complex developmental, environmental and functional change. The surface defences and enzyme systems of the neonatal gut are maturing in a protective film of maternal antibody, while undergoing increasing stimulation from environmental microbial challenge. The precarious nature of this defence system is not surprising. It is contingent upon a balance of such changing conditions as maternal antibody quantity, quality and delivery(5) Bush, L. J., Aguilera, M. A., Adams, G. D. and Jones, E. W. 1971. Absorption of Colostral Immunoglobulins by Newborn Dairy Calves. J. Dairy Sci., 54: 15471549.  [Google Scholar], environmental microbial challenge(46) Smith, H. W. 1965. Observations on the Flora of the Alimentary Tract of Animals and Factors Affecting its Composition. J. Pathol, 89: 95122.  [Google Scholar] (47) Smith, H. W. 1971. The Bacteriology of the Alimentary Tract of Domestic Animals Suffering from E. coli Infection. Ann. N. Y. Acad Set, 176: 110125.  [Google Scholar] and neonatal immunological and intestinal epithelial maturation(7) Corley, L. D., Staley, T. E., Bush, L. J. and Jones, E. W. 1977. Influence of Colostrum on Transepithelial Movement of E. coli 055. J. Dairy Sci., in press [Google Scholar] (52) Staley, T. E., Corley, L. D., Bush, L. J. and Jones, E. W. 1972. The Ultra-structure of Neonatal Calf Intestine and Absorption of Heterologous Proteins. A rial. Rec, 172: 559579. [Crossref], [PubMed] [Google Scholar]. While both infectious and non-infectious etiologic factors are involved(1) Barnum, D. A., Glantz, P. J. and Moon, H. W. 1967. Colibacillosis. CIRVeterinary Monograph Series/Two, : 544.  [Google Scholar] the former (Escherichia coli, Saltiionsllci and Shigella spp., and reo and corona viruses) is the more significant. Enteropathogenic E. coli (EPEC), a major contributor to neonatal diarrhoeal disease, will be discussed primarily. Four syndromes, septicaemia, enteric-toxaemia, local invasive and enterotoxic have been described(32) Moon, H. W. 1974. Pathogenesis of Enteric Diseases Caused by Escherichia coli. Adv. Vet. Sci. Comp. Med, 18: 179211. [PubMed] [Google Scholar] and ad verseoutcomes may result from endotoxic shock and/or hypovolemic shock, from systemic infection and from malnutrition. The clinician is thus faced with the selection of a multi-faceted approach to the problem. Avenues of attack, in addition to prophylactic husbandry, include: passive and active immunization, reduction of challenge, specific antimicrobial therapy, and resolution of fluid and electrolyte loss and shock. This presentation includes a resumé of the calf scour syndrome, together with observations concerning treatment and control. These observations include active and passive immunization, antimicrobial therapy, and modification of intestinal fluid loss.  相似文献   
13.
Following the recent discovery of Libyostrongylus douglassii in ostriches in New Zealand, information relating to this nematode is reviewed. Amongst some of the topics considered are the parasite's distribution and prevalence, its life cycle and survival, and its diagnosis and control. Of particular interest from a New Zealand perspective is the potential for the parasite to infect other ratites, especially the kiwi. While the current evidence suggests that this may be unlikely to occur, the possibility that it might be able to do so cannot be ruled out entirely.  相似文献   
14.
Because of the importance of reproduction in stock breeding systems, it is necessary to find selection criteria that increase reproductive efficiency. The aim of this study was to estimate genetic parameters for the probability of conception on first service (PROB) in Murrah heifers, and its association with other traits of economic interest [age at first calving (AFC), service period, calving interval and milk yield at 270 days], with the purpose of evaluating their use as selection criteria. Reproductive information and first lactation records of 1200 Murrah heifers were used to perform two‐trait analyses between PROB and the other characteristics. Bayesian inference was used to estimate the variance components, considering PROB as threshold and the other as linear factors. The results demonstrate that this trait has heritability of 0.15, indicating the possibility of a genetic gain by using it for selection. With respect to the genetic correlation estimates, the only high‐magnitude association was with AFC (?0.899), which is the current criterion indicating sexual precocity of females. In the light of the parameters estimated, the first‐service pregnancy rate is an alternative for indication of sexual precocity, although presenting a smaller genetic gain than the current standard AFC. Nevertheless, additional research should be conducted regarding this trait to assess the economic importance of its use in dairy buffalo production systems.  相似文献   
15.
Continental extension and volcanism are generally thought to be complementary. Stratigraphic and structural data from some highly extended parts of the Basin and Range province reveal instead that rapid extension appears to have suppressed volcanism. This relation may reflect enhanced crystallization of midcrustal magmas during extension resulting from exsolution of magmatic volatiles, increased interaction of magmas with meteoric water, and dispersal of magma into smaller bodies. Some rift environments may thus be characterized by voluminous synextensional plutonism with little or no concomitant volcanism.  相似文献   
16.
Sustainability issues are becoming increasingly important in Western food consumption. This research aims at identifying ways to increase the market share of sustainable fish from aquaculture by analyzing consumer awareness and preferences for sustainable aquaculture products and by drawing conclusions on improving communication in the German market. An integrative research approach was used: it began with an inventory of sustainable seafood products on the German market, followed by qualitative and quantitative consumer research, and ending with a stakeholder workshop, which reflected on the research outcome with practitioners. Sustainability and country of origin proved to be of minor relevance to the vast majority of the consumers interviewed. Indeed, attributes such as freshness, taste, and price frequently ranked higher. Like most of the other consumers, the small consumer segment that is generally interested in sustainability issues of food also often lacks knowledge of fish farming and its products. Consequently, communication of sustainability in aquaculture is challenging, and the development of this market requires concerted actions along the whole value chain, with the retail sector as the main actor.  相似文献   
17.
Objective The first national abattoir survey of Cysticercus bovis (‘beef measles’) in cattle was conducted in February 2008. Methods During the data collection period, 493,316 cattle were subjected to standard postmortem procedures, including incision of the masseter and heart muscles. On-site veterinarians were asked to record the location of any C. bovis cysts, as well as the National Livestock Identification System ear tag numbers of infected animals. Veterinarians were asked to submit samples for laboratory confirmation by histology and polymerase chain reaction testing. Results Of the 23 samples submitted, none was positive for C. bovis by either diagnostic method. Conclusions Occasional, isolated diagnoses of beef measles are still made in most states of Australia, but since the last regional surveys were conducted 30 years ago, when the estimated prevalence was 50 to 200 per 100,000 cattle slaughtered, the parasite has become extremely rare.  相似文献   
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The fungicides metiram, mancozeb, metiram + triphenyltin hydroxide, propamocarb hydrochloride + chlorothalonil, dimethomorph + mancozeb, cymoxanil + mancozeb, and chlorothalonil were applied by aircraft and through center-pivot irrigation systems (chemigation) to replicated plots in commercial fields of ‘Russet Burbank’ potato. Fungicide deposition and redistribution were indirectly determined by inoculation of excised leaves withPhytophthora infestans and directly by chlorothalonil residue analysis from upper, middle, and lower crop canopies. The effectiveness of two surfactants added with fungicide and applied by aircraft, an increased water volume rate used by aircraft, and a reduced water volume used with chemigation was also determined. The addition of synthetic latex and siliconepolyether surfactants did not increase efficacy of metiram or mancozeb in controlling late blight when applied by aircraft. The protectant fungicides metiram, mancozeb, and chlorothalonil were not significantly different from dimethomorph + mancozeb, cymoxanil + mancozeb, and propamocarb hydrochloride + chlorothalonil in late blight control when applied by aircraft. However, cymoxanil + mancozeb had limited efficacy when applied by chemigation. Fungicide deposition through the canopy differed when air applications were made before or after canopy closure (row closure). Fungicides applied by aircraft prior to row closure protected the entire canopy; whereas, fungicide application after row closure initially protected the top and middle canopies, and subsequent applications and redistribution of the fungicides were needed for adequate protection throughout the canopy. The fungicides and fungicide mixtures tested were evenly deposited throughout the potato canopy with each chemigation application. Severity of late blight did not differ on leaves treated with mancozeb or chlorothalonil applied by aircraft at water volumes of 47 L/ha and 94 I/ha and then inoculated withP. infestans, nor did severity of late blight differ on inoculated leaves previously treated with chlorothalonil by chemigation at water volumes of 15,145 and 50, 571 L/ha.  相似文献   
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