88,788 results

  • The effects of fasting and transport on calves : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science at Massey University

    Todd, Sarah Elizabeth

    Thesis
    Massey University

    The welfare of domestic animals is becoming increasingly important in New Zealand. Consequently, Codes of Recommendations and Minimum Standards are produced by the Animal Welfare Advisory Committee to maintain adequate standards of welfare for animals in our care. These Codes are updated to incorporate new knowledge which may improve welfare standards further. There is one such Code for the welfare of bobby calves. In New Zealand, calves born to dairy cows that are not required for replacements in the herd are slaughtered for human consumption. These 'bobby calves' are exposed to a number of factors which have the potential to compromise welfare. Work in this thesis is based on the recommendations and minumum standards given in the bobby calf code. The general aim of this work was to investigate the combined effects of transport and nutrition on bobby calves, and to assess the ability of the calves to operate within their physiological capacity withoutsignificant welfare compromise during the bobby process. In this study the metabolic effects of feeding and fasting hand-reared dairy calves aged 1-2 weeks were examined over a period of 30 hours. Parameters used to assess the response to feeding and fasting included PCV and plasma concentrations of total proteins, glucose, triglycerides, beta-hydroxybutyrate and urea. In mild climatic conditions and with access to water at all times, it was found that feeding calves the recommended volume of colostrum or milk at 12 hourly intervals was sufficient to maintain high glucose concentrations between feeds. A period of 30 hours without food had minimal adverse effects on calves as they were able to maintain energy levels during this time without excessive use of endogenous energy reserves. There was no evidence to suggest that significant dehydration had occurred. Work in this study included examination of the metabolic effects of transport duration and stocking density in calves that were deprived of food for 30 hours. PCV and plasma concentrations of total proteins, glucose, triglycerides, beta-hydroxybutyrate, urea, creatine phosphokinase and lactate were measured. Three hours of transport at the recommended stocking density (0.2m2/calf) caused minimal adverse effects in food-deprived calves. Food-deprived calves transported for 12 hours at the recommended density maintained normoglycemia for 6 hours longer than non-transported food-deprived calves. This was thought to be caused by a mild increase in physical activity resulting from the need to maintain balance during transport. Thus the physical activity probably produced a glucose-sparing effect by mobilising muscle glycogen. The response of food-deprived calves transported for 12 hours at half the recommended density (0.4m2/calf) was similar to that of non-transported, food-deprived calves. This suggests minimal physical activity occurred at the lower stocking density and this was attributed to the fact that most of these calves lay down during transport. In this study these initial metabolic responses of calves to feeding were evaluated after 30 hours of food-deprivation in transported and non-transported calves, and immediately after transport of 3 or 12 hours duration. Parameters measured included PCV and plasma concentrations of total proteins, glucose, triglycerides, urea and lactate. Feeding after 30 hours without food apparently caused a decrease in glucose clearance. It is thought that this may have resulted from a metabolic overcompensation due to delayed adjustment of hormones and metabolites from the starved state to the fed state. Feeding immediately after transport restored plasma glucose levels to be within the normal range within 3 hours. As indicated by the parameters measured in this study, hand-reared dairy calves appear to tolerate the combined effects of transport and food-deprivation quite well. However the present experiments were conducted in mild climatic conditions. Air temperatures ranged from 7-13 °C and there was little wind or no rain. In situations of climatic extremes, the physiological capacity of calves to withstand the bobby process may not be as great. At higher temperatures there is a risk of dehydration. At lower temperatures, especially combined with wind and rain, an increased metabolic rate may be required to fuel heat production so that endogenous body reserves may not last as long during times of food-deprivation.

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  • Olfactory environmental enrichment of felids and the potential uses of conspecific odours : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Zoology at Massey University

    Roesch, Heidi

    Thesis
    Massey University

    The potential of olfactory stimulation as a tool for the environmental enrichment of captive felids was investigated at Orana Wildlife Park in Christchurch. Six cheetah (Acyninox jubatus), two serval (Felis serval) and one tiger (Panthera tigris) were given various scents: male domestic cat urine; a synthetic analogue of domestic cat facial pheromone; mouse odour; peppermint and catnip, in order to determine whether scent as an environmental enrichment can effectively modify felid behaviour. All of the scents elicited a response that was significantly different to the control presentation. The synthetic feline facial pheromone elicited the greatest response, particularly from the females in the study. However, despite these results, the interest shown in the scents was limited, and due to the small sample size and other constrictions that arise from working with a zoo, the effectiveness of scent as a tool for environmental enrichment remains inconclusive and further research is needed. The further possibilities of scent as an environmental technique were investigated at Massey University's Feline Nutrition Unit. Anoestrous and oestrous female domestic cats (Felis catus) were presented the urine collected form four entire male domestic cats. The social dominance ranking between the four males and the additive relationship between the males and the females in the study was established. Females were presented with different combinations of the male urine in an observation room and their behaviour recorded. The latency to approach each urine sample, the duration of sniffing, the number of flehmen responses and the number of visits to each sample were recorded as measures female interest in the urine samples. The overall level of responsiveness appears to be quite similar during anoestrous and oestrous. During anoestrous females will investigate urine samples, however they do not appear to discriminate between the urine of different males. In oestrous the female response appears to be much more selective. A strong effect of relatedness was found for oestrous females investigating the urine of a related male. The higher the degree of relatedness to the male the lower the interest shown by the oestrous female. The dominant male also appeared to be preferred overall, and the most subordinate male preferred least overall. The dominance hierarchy could not be replicated in this study and any effect shown for dominance rank may potentially be the result of some other characteristic unique to that male. In terms of environmental enrichment potential, the time spent investigating the urine patches was limited, however the fact that oestrous females show different levels of interest in response to the urine of different males suggests that conspecific urine holds information of interest and may be useful as an enrichment tool.

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  • A study of the reproductive performance of two year-old Romney and Border Leicester X Romney ewes after differential feeding and gonadotrophin treatment : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Science at Massey University

    Eastwood, Kenneth Charles

    Thesis
    Massey University

    Irregular pagination: missing page 58

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  • A comparison of the nutritive value of normal and opaque-2 maize for growing pigs in diets containing meat and bone meal with and without amino acid supplementation : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Science at Massey University

    Stables, Nigel Harry John

    Thesis
    Massey University

    Pig meat production in New Zealand has traditionally been associated with the dairy industry, relying upon dairy by-products (principally skim-milk and whey) as major sources of protein and energy for pig feed. However, export market prospects for milk protein led to the diversification of dairy factory products, such as the ultra-filtration of whey protein and lactose extraction of whey. The prevailing economic climate also encouraged dairy farmers to change to whole milk ,anker collection and large numbers of the supplementary pig enterprises were closed down. Despite fluctuations, market prices generally showed an increase and many farmers began investigating alternative food supplies in order to take advantage of these higher prices. Garbage and other edible waste provided only limited scope for expansion, and the main alternative appeared to be the use of cereal grains. The New Zealand pig industry, in the last 5-10 years, has therefore begun to move towards a specialised form of production based upon the use of diets containing a predominance of cereals, similar to what has prevailed in many overseas countries for a longer period. The local report of Kingma and Ryan (1971) illustrates the need for efficiency in the high cost system of production based upon meal feeding. Where skimmilk is the principal ingredient in the ration, the supply of dietary protein is generally adequate due to the high nutritive value of the protein in this feedstuff. However, when the major source of nutrients comes from cereal grains, although these provide a concentrated source of energy, the poor balance of amino acids becomes limiting to the utilization of such rations. In New Zealand there is a restricted range of feeds high in protein and suitable for incorporation into pig rations. They include skimmilk powder, buttermilk powder, meat meal, meat and bone meal, liver meal and fish meal. Alternative sources of protein in soybeans, lupins, field beans and lucerne are being investigated.

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  • The serological and cultural prevalence in sheep of leptospiral infection in the North Island of New Zealand : a thesis presented in partial fulfilment (30%) of the requirements for the degree of Master of Philosophy in Veterinary Pathology and Public Health at Massey University, New Zealand

    Bahaman, Abdul Rani

    Thesis
    Massey University

    A survey of sheep from the North Island of New Zealand was conducted for leptospiral infection. The results of the serological examination showed 20.5 percent of the sheep had titres ( ≥1:48) to Hebdomadis serogroup, 3.8 percent to serovar pomona, 2.6 percent to serovar tarassovi, 2.3 percent to serovar copenhageni and 2.7 percent to serovar ballum. No titres of 1:48 or greater were detected to serovar australis. It was shown that a minimum dilution of 1:24 resulted in many non-specific or cross-reaction. A minimum dilution of 1:48 was more accurate for detecting the serological prevalence of agglutinins to leptospires in ovine sera. In the cultural survey, serovar hardjo was isolated from three animals in one group of sheep. It was considered that the Hebdomadis titres were more likely to represent previous infection with hardjo than with balcanica. Based on the serological and cultural examinations from the general survey and a study farm, a pattern of infection was recorded. The serological prevalence and the geometric mean titre (GMT) of different age groups of sheep from different farms and the lack of success on obtaining further isolates of hardjo indicated that sheep are not the maintenance host for this serovar in New Zealand. Although infection of sheep by serovar hardjo is not uncommon, it is a sporadic occurrence and endemic infection is unlikely to occur. Preliminary investigations on the use of radioimmunoassay in detecting leptospires or leptospiral antigens in urine are presented.

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  • The development and use of radiopaque markers for the assessment of gastric emptying in dogs : a thesis prepared in partial fulfilment of the requirements for the degree of Master of Veterinary Science at Massey University

    Allan, Frazer James

    Thesis
    Massey University

    Currently, there is no suitable technique that can be used by veterinarians in private practice to assess the rate of emptying of solids from the stomach of dogs. Radiographic studies using barium sulphate suspension are commonly employed by veterinarians to assess gastric emptying. However, these methods are qualitative and assess the gastric emptying of liquids not solids. Diseases which affect gastric emptying are more likely to affect the emptying of solids rather than liquids. The objective of this study was to develop a technique that the practising veterinarian could use to assess the rate of gastric emptying of solids in dogs. The study was divided into two parts, the development of radiopaque markers and the development of a method utilising these radiopaque markers that could be used in veterinary practice to assess the gastric emptying of solids. A 1.5 mm diameter (small) marker and a 5.0 mm diameter (large) marker were developed based on studies by other investigators. It was anticipated that the small marker would empty from the stomach with food and the large marker would empty with the onset of the migrating motility complex. Both markers were made from a compound containing high density polyethylene and barium sulphate. The gastric emptying of both sizes of marker was then assessed in 20 healthy, mixed breed dogs. Studies were performed on days one, six and nine of the investigation. After a 24 hour fast, thirty small and ten large markers were placed into a standard meal comprising of canned Prescription Diet® d/d. With the dogs restrained in ventrodorsal and left lateral recumbency, radiographs were taken hourly until all, or most of, the markers had emptied from the stomach. Percent gastric emptying of the markers versus time curves (GEvT curves) were then generated from this data. The time taken to reach the point of inflection on the GEvT curve (the lag phase), and the times taken to empty 25%, 50% and 75% of the markers (T25, T50 and T75 respectively) were calculated from the GEvT curves. The sex and age of the dogs and training the dogs to the radiographic procedure did not have a significant effect on the gastric emptying parameters. There was a weak but significant positive correlation between dog weight and the T50. There were no significant differences in the T25, T50 and T75 between the large and small markers. Contrary to their anticipated behaviour, the large markers left the stomach during the fed motility pattern. A larger, 7 mm diameter marker, may be required to mark the onset of the MMC in dogs. The mean GEvT curve of the small markers on day one (with 95% confidence intervals) was considered to represent the most appropriate gastric emptying reference curve for clinical use. The lag phase of the small markers on day one was 2.45 ± 2.04 hours, the T25 was 4. 85 ± 2.15 hours, the T50 was 6.05 ± 2.99 hours and the T75 was 8.32 ± 2.72 hours. If delayed gastric emptying is suspected, taking two or three sets of radiographs at regular intervals from 6-16 hours after feeding and comparing the results with the reference curve is probably the most appropriate method of assessing gastric emptying in a patient. Conversely, if excessively rapid gastric emptying is suspected, taking two or three sets of radiographs at regular intervals from 0-5 hours after feeding and comparing the results with the reference curve is most appropriate. In conclusion, radiopaque markers provide a simple quantitative method of evaluating the gastric emptying rate of dogs. However, the results of this study have not established that the gastric emptying of the small markers occurs at the same rate as the gastric emptying of food. In addition, the sensitivity and specificity of this diagnostic procedure still needs to be determined. These steps in the validation process are currently being carried out at the Department of Veterinary Clinical Sciences at Massey University.

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  • A histochemical study of bovine salivary gland secretory products and an investigation of intraepithelial granular duct cells of the parotid gland : a thesis presented in partial fulfillment of the requirements for the degree of Master of Philosophy in Physiology and Anatomy at Massey University

    Gurusinghe, Chandan Jayaraj

    Thesis
    Massey University

    Paraffin wax embedded histological tissue samples of bovine salivary glands were examined by staining, histochemical and immunohistochemical methods. The characteristically tubular secretory endpieces were composed of either proteoserous cells or mucous cells and demilunes. Parotid glands and the histologically identical ventral buccal glands were composed entirely of proteoserous cells which occasionally contained diastase resistant PAS positive neutral glycoproteins, additionally confirmed by acetylation and saponification. Immunohistochemical studies established that most proteoserous cells also contained either protein band 4 or band 10. An examination of sheep and cattle parotid glands revealed that basal striations were absent from intralobular ducts of cattle but were abundant in those of sheep. Some duct cells contained diastase labile and diastase resistant PAS positive material and apical blebs. A granulated intraepithelial cell type, which was ultrastructurally examined and found to be similar to a globule leucocyte, was specific to intralobular duct walls of the parotid glands; their precise function was not established. The main excretory duct of the parotid gland contained several goblet cells. The mandibular gland mucous cells contained acidic and neutral mucosubstances. The presence of acidic groups was confirmed by methylation, saponification and neuraminidase digestion. The conspicuous demilunes contained acidic and neutral mucosubstances and acidophil granules which contained protein band 8. Intralobular ducts with tall columnar cells were basally striated. Goblet cells were not identified in the main excretory duct. The sublingual gland mucous cells contained neutral and acidic mucosubstances; the latter were not neuraminidase labile. Unlike the mandibular glands, the sublingual mucous cells stained for sulphate goups, attributed to sulphated or sialo-sulphated glycoproteins, since hyaluronidase digestion did not eliminate basophilia at low pH. The demilune cells were mostly proteoserous and contained protein band 9. The "striated" intralobular ducts were identical to those of the mandibular gland. Intermediate buccal, dorsal buccal, palatine, posterior tongue and pharyngeal glands mucous cell histochemical composition was similar to those of the sublingual glands. The demilune contents of the minor glands were mainly proteoserous; however those of the pharyngeal and posterior tongue occasionally contained acidic and neutral mucosubstances. Two unusual features of the minor glands were the presence of goblet cells in intralobular ducts of the pharyngeal glands and the appearance of an atypical secretory mechanism in dorsal buccal, intermediate buccal and palatine glands, the secretions of which frequently contained cellular debris mixed with mucus. Humoral immunity in bovine salivary glands was mediate by sublingual, mandibular and pharyngeal glands, three glands which contained abundant subepithelial plasma cells The parotid and ventral buccal glands noticeably lacked plasma cells but contained intraepithelial granular duct cells. It was proposed that these cells may provide cell-mediated immunoprotection against bloat since increased numbers of these cells have been reported in animals with low bloat scores. Salivary protein band 4 from parotid saliva has been correlated with bloat susceptibility in cattle, but was equally distributed in parotid tissues of both low and high bloat susceptible animals, suggesting that band 4 is synthesised but not secreted by low bloat strains.

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  • A study of biases in dairy sire evaluation : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Science at Massey University

    Anderson, Robert Donald

    Thesis
    Massey University

    Text on several pages including the Abstract is not clear.

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  • Employment relations in a changing world : a comparison of outcomes for New Zealand workers under neoliberalist and third way regimes : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Social Policy at Massey University, Palmerston North, New Zealand

    Harte, Anne

    Thesis
    Massey University

    This research is an examination of the effect of recent world changes on political-economic strategies in industrialised countries, and the subsequent developments in employment relations. The three major strategies included are neoliberalism, the third way, and social partnership. The trends covered under employment relations focus on decentralisation, labour market flexibility, workforce skill and education, and union decline. Overall the thesis is aimed at describing and analysing the changes to employment relations under these three strategies, then at assessing and comparing the related outcomes for workers in New Zealand under the neoliberalist and third way approaches. A qualitative approach was used in the thesis through informal conversations with key New Zealanders to determine worker goals. Supporting this was a literature search on worker goals worldwide which relied on comparative policy research methods. Both aspects then provided the basis for selection of the relevant measures of outcomes for local workers. A quantitative approach was necessary in gathering and analysing the data required to actually measure outcomes for workers under the neoliberalist and third way strategies. This enabled assessment and analysis of the results of the policy-making linked to these political-economic strategies in this country. A comparison of the outcomes for New Zealand workers under neoliberalism and the third way was then feasible, providing some indication as to which approach has been most beneficial for workers in this country. The main findings of the study focus on the outcomes fQr workers in New Zealand, which are seen as resulting largely from neoliberalist and third way policy-making (or the lack of same), and the related trends in employment relations. The more negative trends in line with international patterns in employment relations occurred under neoliberalism, while the more positive trend of workforce skill and development was more prevalent under the third way. In terms of actual results, the third way in comparison to neoliberalism has not delivered significantly better outcomes to New Zealanders. While the neoliberalist regime certainly instigated the changes that caused such dramatic declines for workers during the 1990s, most of the recent improvements under the third way seem to be a diluted continuation of earlier positive trends, although this is also the case where negative trends have persisted. Generally the third way approach has acted to halt earlier declines rather than reversing negative outcomes in any substantial way. Where the neoliberalist approach was fairly indiscriminate in disadvantaging workers, the third way appears to have mostly been of benefit to the average working New Zealander, rather than assisting the more marginalised groups.

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  • An evaluation of abattoir data for disease surveillance : this thesis represents 70% of the assessment requirements for the degree of Master of Philosophy at Massey University

    Marero, Ricardo Ferre

    Thesis
    Massey University

    Data from abattoirs were evaluated to determine their usefulness for disease surveillance. Self-acquired data from three surveys conducted at abattoirs and routinely generated disease statistics from meat export slaughterhouses were analysed. Three techniques were employed in the analysis of these available data from New Zealand abattoirs. Returns from a large scale survey of bovine ocular squamous cell carcinoma were indexed on printed cards as a filing system and those from the serological surveys of two separate groups of abattoir workers were converted into computer system files. The "pencil and paper"-calculator method was used for the recorded disease statistics. Conversion of survey returns into system files facilitated the handling of data. Manual sorting in a card index system provided new information on the epidemiology and economic importance of squamous cell carcinoma of the bovine eye in New Zealand. The rate of "cancer eye" in Herefords and Hereford crosses was 403/100,000 compared to 8/100,000 in other breeds. Further investigations indicated that these differences were associated with pigmentation of the ocular structures. The data from the serological surveys among abattoir workers were conveniently manipulated in the computer and provided information of the risk factors involved in three potential zoonoses at the works. Both leptospirosis and brucellosis were shown to be occupational hazards. In the case of leptospirosis, direct pig contact appeared to constitute the greatest risk, while in brucellosis, one of the more important correlations was in relation to time employed in the Meat Industry. Toxoplasmosis did not appear to be an occupational disease. The information derived on these files were dependent on the manner of organisation (e.g. establishing variables from measurements, coding values) of the data originally obtained from the disease surveys carried out by others. Routinely generated vital statistics of the prevalence of "Diseases and Defects" recorded by the Meat Division of the Ministry of Agriculture and Fisheries were examined and analysed. Analysis of variance tests were applied to selected conditions to determine regional variations. The application of statistical tests uncovered the subtleties of each group of data and revealed information on disease prevalences. True geographical variations in the prevalence of sarcocysts, caseous lymphadenitis and pleurisy of sheep were demonstrated. Through these techniques useful information was derived from data generated by these three disease surveys carried out at the abattoir and from routinely recorded meat inspection statistics. Information obtained from the surveys is discussed in relation to previous studies on the same topics. Routinely recorded vital statistics were appraised for accuracy and their usefulness in studying variations in disease prevalence. The evaluation of data and information obtained during these investigations manifests the potential of the abattoir as a source of useful information for disease surveillance.

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  • Aspergillus flavus and the deterioration of farm-stored barley grain : a thesis presented in partial (30%) fulfilment of the requirements for the degree of Master of Philosophy in Veterinary Pathology & Public Health at Massey University

    Hussein, Hassan M

    Thesis
    Massey University

    For many years there was a tendency to regard moulds in grains destined for animal consumption as of little significance other than as gross spoilage organisms. Investigations of the possible role of toxic fungi in diseases of grain-fed animals was confined in the main to problems of restricted local significance (Forgacs and Carll, 1962). However, it was the discovery of aflatoxin in 1961 and the widespread concern which it generated, which inspired a vast amount of research into the natural production of mycotoxins and the consequent mycotoxicoses affecting both animal and human health, aspects of which have been fully reviewed in a number of recent publications (Purchase, 1974; Rodricks, 1976; Rodricks et at., 1977; Wyllie and Morehouse, 1978 and Cole and Cox, 1981). Mycotoxin production can occur anywhere, in the field, or during harvest, processing, storage and shipment, or during the feeding period on the farm. Commodities grown and stored in areas where high levels of insect damage and poor farming and storage practices prevail appear to be the most susceptible (Ciegler, 1978). Nevertheless, natural contamination with a variety of mycotoxins has been reported for most of the major agricultural commodities in the world (Hesseltine, 1974) and those mycotoxins currently of most concern are: aflatoxin, trichothecenes, zearalenone, ochratoxin, citrinin and some tremorgens (Ciegler, 1978). However, there are over 23 known mycotoxins which can be associated with grains and some of those currently less well known may prove to be significant in the future.

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  • Some aspects of protein nutrition and its relation to wool growth and body weight changes in the sheep : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science at Massey University

    Carrico, Robert G

    Thesis
    Massey University

    Early studies involving dietary protein level effects on wool growth (Fraser and Roberts, 1933; Slen and Whiting, 1952; Ferguson, 1959) noted that over a wide range, dietary protein level remains relatively independent of wool growth rate. These observations led to the conclusion that once minimum protein levels were met, dietary protein was no longer a major factor limiting wool growth (Ferguson, 1959). For some time dietary protein has been known to be involved in a complex series of biochemical reactions within the rumen (reviewed by Barnett and Reid, 1961). Host notable of the reactions related to this study are those involved with deacination and fermentation of protein by the rumen microorganisns. After considering results of protein level experiments, knowledge of rumen microbial action on protein, and work with sheep indicating that nitrogen retention was increased by abomasal or duodenal protein infusions (Cuthbertson and Chalmers, 1950), Reis and Schinckel (1961) decided to by-pass rumen action by administering casein supplements through an abomasal cannula. The effect of "by-passed" protein supplements on wool growth rate was then assessed. Following supplementation, wool growth rate increased by 41 to 77%. These results suggested that protein nutrition is a major factor limiting wool growth.

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  • The morphology and morphometrics of lymph nodes of sheep and lambs: a study of normal sheep and those with arthritis : a thesis presented in partial (20%) fulfilment of the degree of Master of Philosophy in Veterinary Pathology and Public Health at Massey University, New Zealand

    Yao, Shutang

    Thesis
    Massey University

    During the history of man, the most serious meat borne diseases were probably trichinellosis and tuberculosis. Owen was the first person to recognize Trichinella spirallis (Hoeden, 1964) and Koch the first to isolate Mycobacterium tuberculosis (Martin, 1978) in 1835 and 1882 respectively. These diseases had been a major cause of human morbidity and mortality for many centuries before the infectious agents were described. It is interesting to note that lesions of tuberculosis were found in mummies of the Rameses dynasties which are some 30 centuries old and human trichinellosis occurred in early epochs of European civilization without it being realised. With the development of modern concepts of disease, greater attention was paid to the source and handling of meat for human consumption (Brandly, Migaki and Taylor, 1966). Since meat is an essential source of human food, a knowledge and understanding of potential meat borne diseases is necessary. It has become accepted that meat inspection is an indispensable branch of meat hygiene in relation to the control of meat borne diseases.

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  • The recording and analysis of animal health data on New Zealand dairy farms : a thesis presented in partial fulfilment of the requirements for the degree of Master of Veterinary Science at Massey University

    McKay, Bryan Joseph

    Thesis
    Massey University

    Significant progress has been made in the last three decades in reducing the prevalence of animal diseases that cause mortality. However, there is an increasing concern with significant losses associated with diseases that cause a reduction in production efficiency, especially in western countries. In response to this the disciplines of epidemiology and economics are being applied to animal health problems to evaluate causal relationships between contributing factors and health problems, predict the economic benefits of control methods, and prescribe the optimal preventive and/or control measures for these problems. In order to measure the impact of a disease, one has to be able to identify the effects it has on the animal. This is not a simple task because disease effects a) are not always obvious and pronounced; b) are influenced by factors such as management, environment and others; c) have a temporal dimension which adds to the complexity of evaluating their impacts at different stages in time; d) often manifest themselves as part of a complex involving other diseases. In an attempt to overcome the above problems, and to produce an aid to veterinarians promoting health management services to New Zealand dairy farmers, a computerised information system, DairyMAN, was developed with the specific requirements of the New Zealand dairy scene in mind. This thesis is a report of the development of the program DairyMAN, the philosophy behind the design structure and field operation of the program. The results of the use of the program to analyze records, and in combination with an advisory service, are reported for a particular farm. Over an 18 month period the return on investment made by the farmer on this service was conservatively estimated at 175%. The author concluded that the program, although still evolving as additional features are added, effectively supports the activities of veterinarians involved in health management services. It also produces a valuable data base on which epidemiological research may be carried out

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  • Public health aspects of Yersinia pseudotuberculosis in deer and venison : a thesis presented in partial fulfilment (75%) of the requirements for the degree of Master of Philosophy in Veterinary Public Health at Massey University

    Bosi, Edwin

    Thesis
    Massey University

    A study was conducted to determine the possible carriage of Yersinia pseudotuberculosis and related species from faeces of farmed Red deer presented for slaughter and the contamination of deer carcase meat and venison products with these organisms. Experiments were conducted to study the growth patterns of Y.pseudotuberculosis in vacuum-packed venison stored at chilling and freezing temperatures. The serological status of slaughtered deer in regards to Y.pseudotuberculosis serogroups 1, 2 and 3 was assessed by Microplate Agglutination Tests. Forty sera were examined comprising 19 from positive and 20 from negative intestinal carriers. Included in this study was one serum from an animal that yielded carcase meat from which Y.pseudotuberculosis was isolated. Caecal contents were collected from 360 animals, and cold-enriched for 3 weeks before being subjected to bacteriological examination for Yersinia spp. A total of 345 and 321 carcases surface samples for bacteriological examination for Yersiniae were collected at the Deer Slaughter Premises (DSP) and meat Packing House respectively. A total of 70 venison sausages were purchased from local supermarkets. Direct plating and plating after 21 days cold-enrichment were carried out to examine for Yersiniae. Venison samples were obtained from the DSP and seeded with a known approximate number of Y.pseudotuberculosis organisms. The samples were vacuum-packed and stored at temperatures of +10°C, +4°C, -1°C, -10°C, -13 ±2 °C,and -20°C; recovery and enumeration of the test organism was made at predetermined times. The results of the Microplate Agglutination Tests showed that deer presented for slaughter at this DSP had low (1:10) or undetectable antibody titres to Y.pseudotuberculosis. The prevalence of Yersinia spp, in faeces was 5.3% (19/360) of Ypseudotuberculosis, 2.6% (9/360) of Y.enterocolitica. 3.6% (13/360) of Y.kristensenii, 20.5% (74/360) of Y.frederiksenii. 0.6% (2/360) of Y.intermedia and 0.6% (2/360) of Y.rohdei. Five of nine strains of Y.enterocolitica isolated were found to be potentially pathogenic by means of the virulence marker tests. Two of them were identified as biotype 3 serovar 0:5,27. There was only one isolation (0.3%) of Y.pseudotuberculosis from 321 carcases sampled at the Packing House. The prevalence of Yersinia spp, in venison sausages was 11.4% (8/70) Y.enterocolitica. 1.4% (1/70) Y.kristensenii and 5.7% (4/70) Y intermedia. Y.pseudotuberculosis grew very well in vacuum-packed venison stored at chilling temperature although a long lag phase was observed at -1°C. When frozen, the organisms remained viable for a long period of time and recovered and multiplied rapidly when transferred to chill temperature. The study showed that there was no serological evidence of yersiniosis in deer presented for slaughter during the study period despite the fact that 5.3% of the animals were carrying Y.pseudotuberculosis in their faeces. While there was a low prevalence of Y.pseudotuberculosis on carcase meat their presence could be a source of cross contamination of other carcases especially during deboning. The finding of Yersiniae in venison sausages showed that there was contamination during their preparation. The multiplication of the bacteria in vacuum-packed venison and their long survival in frozen venison are of public health concern while its presence may affect export markets.

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  • The characterisation of strains of Mycoplasma ovipneumoniae by restriction endonuclease analysis : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Microbiology at Massey University, New Zealand

    Mew, Alison Jane

    Thesis
    Massey University

    Studies of the pathogenicity of Mycoplasma ovipneumoniae would be facilitated by an in vitro method of identifying and classifying isolates of this organism, and it is with the development of such a method, and its possible applications, that this thesis is mainly concerned. The method chosen was Restriction Endonuclease Analysis (REA) which has already been successfully applied to the identification of some viruses and bacteria. Initially the REA patterns of 2 strains of M. ovipneumoniae were observed. They differed markedly in restriction pattern, but the pattern exhibited by any one of them was recognisable and reproducible. Furthermore, patterns did not change significantly after limited passage in vitro. An extension of this study to 8 isolates from widely differing sources, showed that all gave markedly different patterns. It was concluded that, unlike the findings for Leptospira and Rhizobium, REA could not be used for the identification of species, but is an extremely powerful method for identifying strains of M.ovipneumoniae. Despite the marked heterogeneity of isolates from different sources, the relative stability of pattern of an individual isolate, suggested that REA could be used to examine the epidemiology of individual strains of M. ovipneumoniae within a flock of sheep. Hence, we undertook a study of M. ovipneumoniae isolates obtained by serial swabbing of the nasal cavities of a flock of lambs over a 6-month period, and from the lungs of the same lambs at slaughter. It was shown that 54 isolates from the nasal cavities fill into 7 major groups with respect to restriction pattern (although minor differences were detected within a group). There was a tendency for these groups to occur sequentially. None of the isolates were shown to persist for long periods, but a later strain could replace an earlier one. The isolates from the lungs were more homogeneous and the predominant strain fell within one of the 7 "nasal" groups. This suggests that nasal isolates may vary in their pathogenicity for the lungs, although other explanations are possible (see General Discussion). Notwithstanding the apparent stability of mass cultures of M. ovipneumoniae following limited passage in vitro, the unexpectedly large number of restriction patterns found with field strains, led us to re-examine, in more detail, the stability of cloned isolates. A multiply-cloned isolate was propagated in vitro and 8 sub-clones selected before and, a further 8 sub-clones after 20 passages. Some limited heterogeneity was detected among the 8 sub-clones selected before passage, and a somewhat greater degree of heterogeneity was detected among sub-clones selected after passage. It should, however, be emphasised that these differences were small compared to the total lack of similarities seen when isolates from different sources were examined. Limited passage in the presence of sub-lethal concentrations of antibody did not increase the heterogeneity of patterns - if anything, the reverse is true. Explanations for these findings and Future experiments to confirm or deny these possibilities are discussed.

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  • The chemiluminescence of ovine neutrophils : a thesis presented in partial fulfilment of the requirement for the degree of Master of Veterinary Science at Massey University

    Eagleson, Jane

    Thesis
    Massey University

    The development, structure and function of polymorphonuclear leucocytes (PMN) is reviewed and methods for determining neutrophil competence are discussed. A technique, based on differential centrifugation and red blood cell lysis, is described for isolating neutrophils of 80 to 90% purity from ovine blood. A standardised, luminol-enhanced chemiluminescence (CL) assay was developed for ovine neutrophils using latex beads as the phagocytic stimulus and some conditions influencing the level of CL generated are described. Normal sheep of similar age, housed under identical conditions and bled at approximately the same time on different days produced CL responses ranging from 386 to 3084 millivolts (mV). Animals sampled once daily over 5 days showed large fluctuations in CL values both between and within individuals. Furthermore, sheep bled at 4 hourly and 6 hourly intervals for 48 and 96 hrs respectively produced CL responses in a single individual with a range of 618 to 2946 mV. There was no evidence of periodicity in CL activity over the time periods examined. Since peak CL responses showed such large variations between individuals, integrated CL values were also measured. Variations between and within individuals similar to those recorded by peak CL were seen in these results. To examine the possible role of genetic differences in neutrophil function on the variability of CL, pairs of bovine monozygous twins were sampled. There was no correlation in CL response between genetically identical animals with the CL values from pairs of animals differing by as much as 2943 mV. The effect of cortisol on PMN CL was assessed. Synthetic corticosteroid in vivo and in vitro did not increase the peak CL response from isolated neutrophils. Profiles produced by recording CL against time were examined. Some cell isolates produced single peaked profiles while others gave a double peaked response. Single and double peaked profiles were recorded from the same donor at different times during a 24 hr period. Storage of the cells for prolonged periods sometimes resulted in an increase in the magnitude of the first peak possibly indicating an increase in the amount of more readily available myeloperoxidase (MPO). Prominent first peaks were still displayed after the cells were washed and resuspended in fresh media suggesting that the more readily available MPO was cell attached rather than truely extracellular. Neutrophils from ceroid lipfuscinosis-affected sheep produced peak CL responses and CL profiles similar to those given by normal sheep. These results did not confirm the postulated myeloperoxidase deficiency of this condition. It is concluded that ovine neutrophil CL is subject to large variations which cannot be controlled by standardising the cell isolation and CL analysis techniques. The assay is therefore unsuitable as a measure of neutrophil function where single samples are examined. Where there are consistant differences between individuals over a number of days, then CL may be of use when considered in conjunction with other tests of PMN function.

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  • The use of oestrous cows for the pre-collection preparation of mature bulls standing at an artificial breeding centre : a thesis presented to the Victoria University of Wellington in partial fulfilment of the requirements of the degree of Master of Agricultural Science, Massey College, New Zealand

    Macmillan, K L

    Thesis
    Massey University

    Since 1949, a marked expansion in the commercial operation of artificial breeding has taken place in New Zealand. This expansion represents an increase from 1,400 inseminated cows in 1949, to 556,000 inseminated cows in 1961. (New Zealand Dairy Prod, and Marketing Board Ann, Rept. (1962)). The principle objective of the Artificial Breeding Service is to offer farmers the use of top sires from each of the main dairy breeds in New Zealand. These sires are selected on the basis of progeny test records. The rating which each proven sire receives is calculated from the butterfat production records of a sire's daughters. The butterfat records of each daughter are corrected for are differences and compared with the age-corrected average production of the herd-mates. Bulls selected for use as A.B. sires are placed at one of the two Artificial Breeding Centres which provide a Dominion-wide coverage. Because of the seasonal nature of daily farming in New Zealand, the bulk of the demand for semen occurs during the spring mating period, and since chilled semen is the principle form of service offered, the bulls experience a peak working period of eight to twelve weeks at this tise of the year. Ths objective in development at the Centres has been to obtain maximum coverage from top sires compatible with satisfactory conception rates. In 1961, the 49-day non-return rate to first inseminations with chilled semen was 63/3% (New Zealand Dairy Production and Marketing Board Ann. Rept. (1962)).

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  • An evaluation of the efficacy of orally administered copper glycine complex, copper amino acid chelate, copper sulphate, a copper oxide wire particle bolus and a copper edetate injection in New Zealand dairy cows : a thesis presented in partial fulfillment of the requirements for the degree of Masters in Animal Science, Massey University, Palmerston North, New Zealand

    Balemi, Shaun Christopher

    Thesis
    Massey University

    This thesis set out to examine the difference in efficacy of the most commonly used copper supplements in New Zealand dairy herds. There is limited information on copper supplementation in New Zealand dairy cattle in the area of chelated (organic) verses sulphated (inorganic) supplements and this study was designed to provide more information to the New Zealand dairy industry. Sixty non-pregnant mixed age Friesian dairy cows, on the basis of liver copper concentrations, were randomized into 6 groups of 10 animals so that each group had the same mean liver copper concentration. The treatments were Group 1, non-supplemented control; Group 2, 150mg copper/day as copper glycine chelate drench; Group 3, 150mg copper/day as copper amino acid chelate drench; Group 4, 150mg copper/day as copper sulphate drench; Group 5, 20g copper oxide wire particles administered as a bolus and Group 6, l00mg of copper, as calcium copper edetate, administered as a subcutaneous injection on days 1 and 58. The duration of the study was 116 days and the cows were fed baleage, with limited access to pasture. On days -5, 14, 28, 58, 86, and 116 after supplementation, liver samples were obtained by a biopsy technique and blood from the coccygeal vein for copper determinations. The mean initial copper concentration in the liver of the cows used in this study was 827 (SE 109) μmol/kg fresh weight (FW). The mean liver copper concentration of the cows in the control group decreased significantly (P<mol/kg FW). The mean liver copper concentrations of the group which received the copper oxide wire particle boluses were consistently greater than the control group; however a significant difference was only achieved at the day 58 sampling. The group injected with copper edetate achieved a significant rise in liver copper concentration on day 86 after being injected on day 58. However, when the group was injected at day 1 no significant rise was achieved at day 14, 28, or 58. The copper supplements had no effect on serum copper concentrations. Despite the large variation (SE 109) in initial liver copper status between the cows, this did not influence the amount of copper stored in the liver regardless of the copper supplement used. The data was analysed in two groups, cows with lower liver copper (553 μmol/kg FW). and cows with higher liver copper (1050 μmol/kg FW). and there was no difference between the two groups in response to the copper treatments. The initial liver copper concentration of the cows was high. A copper intake of 150mg copper/day was effective in increasing the copper concentration of the liver of dry non-pregnant New Zealand dairy cows. As an oral supplement, copper glycine chelate was more effective in increasing liver copper concentrations than copper sulphate. Overall the oral supplements (copper glycine, copper amino acid chelate, and copper sulphate) were more effective in increasing liver copper concentration than the copper oxide wire particle bolus and the twice given 2ml copper edetate injections. The copper oxide wire particle bolus maintained liver copper concentrations at 843μmol/kg FW which is an adequate liver copper concentration. Therefore in this situation where liver copper concentrations where adequate prior to supplementation the bolus did provide enough copper. This study indicated that in order to maintain liver copper concentration in dry non-pregnant New Zealand dairy cows, on a low copper diet, a 2ml injection may have to be given every 45 days.

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  • Behavioural therapy success and the effect of socialisation on subsequent behaviour in dogs : a thesis presented in partial fulfilment of the requirements for the degree of Master of Veterinary Studies at Massey University, Palmerston North, New Zealand

    Ward, Mathew Roger

    Thesis
    Massey University

    CD-ROM accompanying hard copy in the library contains Microsoft Excel 97 files (data from chapters 2 and 3) and Microsoft Word 97-2003 (socialisation effect and therapy success questionnaires)

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