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End date: 1979Subject: search.filters.subject.Sheep

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    The profitability of beef production on some New Zealand sheep farms : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Farm Management at Massey University
    (Massey University, 1971) Lowe, Kevin I.
    New Zealand sheep farmers are currently receiving product prices which, when considered in relation to their farm costs, are the lowest they have been for many years. Wool prices appear unlikely to recover to levels experienced ten years ago and many sheep farmers are still relying on wool as a major source of farm income. There is an increasing awareness that beef animals can no longer be regarded as aids to good sheep husbandry and instead, must make a direct contribution to farm income. The increasing acceptance of animals of dairy origin as beef-producers, and continued confidence in the long-term market for beef, have helped provide a climate for large-scale moves toward beef-production on many New Zealand sheep farms. As a consequence, there has been a rapid increase in demand for economic information on all aspects of beef production and particularly with relation to established sheep enterprises. It is intended that this thesis shoud go some way towards meeting this demand. [From Introduction]
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    A study of the Romney fat lamb ewe, with particular reference to milk secretion and its effect on fat lamb production : thesis submitted by "392" [Alan Graham Logan] for the M. Agr. Sc. degree at Massey University
    (Massey University, 1946) Logan, Alan Graham
    One of the distinguishing characteristics of mammals, is the dependance of the young, during early post-natal life, on nourish­ment secreted by the mammary gland of the mother. Hence milk secretion is of fundamental importance in all our farm animals with the exception of poultry. The essential attributes of milk (viz., high water content and liquid state, high digestibility, high protein content of excellent biological value, high calcium and phosphorus and the presence of most of the necessary vitamins) are specially suited to the needs of young rapidly growing animals. In dairy cattle extensive study has been made of milk­ producing ability and conscious effort made to improve this by breeding, and nutrition. Comparison of the characteristics of modern dairy cattle (highly developed milking qualities but inferior meat carcasses) and of beef cattle (early-maturing and good carcass quality but often poor milk yield) clearly indicate the extent of improvement from the wild form and the variation in productive efficiency of different types. Valuable work on the milk-producing ability of other species, and its relationship to the welfare of the young has been carried out by Bonsma and Oosthuizen (1) and Donald (7) with Sows; and Ritzman (30), Fuller and Kleinhanz (10), Neidig and Iddings (24), Bonsma (2,3), 30a, Pierce (27,28) with ewes of non-milking breeds, and by several workers with specialised milking sheep, Scheingraber (31), Muhlberg (23), Maule (17). [From Introduction]
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    A study of the effects of plane of nutrition on milk secretion and lamb growth in Romney sheep, and the effect of weaning date on the growth of Romney lambs : a thesis presented in partial fulfilment of the requirements for the degree Master of Agricultural Science of the University of New Zealand
    (Massey University, 1952) Murray, Paul Frederick
    The productivity of an animal depends on two factors, its potentiality, which is governed by its hereditary make-up, and the extent to which that potentiality is allowed to develop, this being regulated by the environment that characterises the habitat. The effects of genotype are obviously shown by the differences between breeds of stock in the amount and quality of meat, wool and milk they produce; but within breeds these effects are not so apparent though they have been conclusively demonstrated, e.g. yield and quality between flocks of Romney sheep. Environmental influence on productivity is limited at the maximum level by the genotype, i.e. no matter how good the environment, the animal cannot produce more than the maximum ordained by the genes it possesses. Conversely, below the genotypic maximum, the environment can regulate the coiling level of production. This interplay of factors is well illustrated by the adaptability of different breeds of sheep to different habitats, e, g. the Romney is predominant in the North Island hill country while in the South the Merino and its crosses assume a greater importance. Within a population with approximately common genotype, e.g. a single flock of uniform breed, the effects of environment below the threshold set by the genotype can be widely varied, e.g. the growth of lambs in a drought can be severely set back. It is with the effects of a particular factor of environment, i.e. nutrition, on the milk production and lamb growth of such a population that this investigation is concerned.
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    Some aspects of the bone-muscle relationships in New Zealand lamb and mutton carcasses : a thesis presented at Massey Agricultural College in partial fulfilment of the requirements for the degree of Master of Agricultural Science in the University of New Zealand
    (Massey University, 1961) Russel, A. J. F.
    The three main constituents of a meat carcass are bone, musele, and fat, and of these the lean meat or muscle is of greatest interest and importance to the consumer. Bone represents an almost total waste and is hence considered as undesizable and as something which must be accepted with the desirable muscular tissue. In the words of Robert Bakewell, "You can't eat bone, therefore give the public something to eat." (Dawson, 1957). The Physical properties of muscle and bone are markedly different. Muscular tissue is compressible and hence difficult to ensure with accuracy on a linear scale. The intimate association of skeletal muscle with other tissues makes its complete removal for accurate weight estimation both difficult and tedious. Bony tissue, on the other hand, lends itself more readily to the measurement of linear dimensions and weight.
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    A study of pasture pattern in relation to microtopography : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science at Massey University
    (Massey University, 1966) Rumball, Peter John
    An important aspect of the science of plant ecology is the determination of the nature and causes of variation in vegetation. Reflecting the controlling influence of the physical environment, this variation is continuous both in space and in time. The most rewarding means of unravelling the intricate relationships between vegetation and habitat is through the detection and analysis of pattern. In an ecological context, pattern may be defined as the non-random distribution of vegetation units within a defined area. This means in effect, that the distribution is either more contagious or more regular than could be expected, if chance was the only factor which influenced the distribution. Greig-Smith (1964) described a random distribution as one in which the presence of one individual (unit) does not either raise or lower the probability of another occurring nearby. The existence of pattern in vegetation is apparently a universal phenomenom. It may be manifest on a very wide range of scales and intensities; from broad global-wide belts of vegetation, down to the variable performance of a single species over a small are.. Causes of pattern may be either intrinsic, (e.g. method of dispersion, competitive ability) or extrinsic, (e.g. variations in the effective physical environment). [From Introduction]
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    The mycoflora of fleece wool : a thesis presented in partial fulfilment of the requirement for the degree of Master of Science in Microbiology at Massey University
    (Massey University, 1976) Lim, Soo Chun
    A study has been made of the variation in the total population of fungi within sheep fleece in vivo with time, and also of the types of moulds and yeasts present within this environment. Fungi were isolated by dilution plating and by the brush technique at the two temperatures of 25C and 37C. Considerably larger numbers of fungi were isolated at the lower temperature. There was no apparent correlation between fungal numbers within fleece wools and the environmental rainfall, either at the time of sampling or on a monthly average basis. The total population of moulds able to grow at 25C did, however, vary with the average monthly environmental temperature. No such correlation existed for moulds growing at 37C nor yeasts at either temperature. Fungal numbers were unaffected by pretreatment of the sheep with commonly used insecticides variously applied, and seemed more related to general environmental conditions than to mode of pretreatment. Possible factors contributing to variations in the total fungal populations of fleece wools are discussed. The types of fungi isolated from wools could be grouped into very frequently isolated species, e.g. Alternaria alternata, Phoma spp., Torulopsis candida, frequent species, e.g. Mucor racemosus, Aspergillus fumigatus, occasional species, e.g. Cladosporium herbarum, Epicoccum purpurascens, Fusarium oxysporum and very occasional species, e.g. Aspergillus niger, Geotrichum candidum, Peyronellaea glomerata. A study of the spatial distribution of the fungi within the fleece was made by an impression technique involving both microscopic and cultural examinations. Most fungi were present in the median parts of the staple and numbers decreased towards the tips and basal parts of the fleece. Again, the most frequent types included Alternaria alternata, Fusarium culmorum and Phoma spp. Of the 68 isolated species, 19 were tested for their ability to degrade autoclaved and propylene oxide sterilised wool in vitro. While Aspergillus niger and Penicillium canescens were consistently unable to degrade either of the wools, most of the tested species degraded both autoclaved and propylene oxide sterilised wool. The degradation of wool by these fungi resulted in the release into the culture medium of cortical cells from the wool fibres. It is postulated that degradation occurred as a result of the breaking down of cementing materials holding the cortical cells together and did not involve true keratin digestion. Wool degraded by fungi was densely stained by lactophenol cotton blue. It is suggested that this activity could be useful in estimating the ability of fungi to degrade wool, even though undegraded wool was lightly and irregularly stained. As several fungi were shown to be capable of breaking down wool in vitro, further tests were made to determine which of these species are potentially able to grow within fleece in vivo. Of those able to grow at skin temperature and which were unaffected by the fatty materials present in wool, Sordaria fimicola . and Aureobasidium pullulans were the two species most likely to grow in the natural fleece environment. The significance of the work reported here is discussed. Many of the fungi commonly isolated from fleece wools have been reported to cause opportunistic fungal infections in man and animals and are also capable of spoiling refrigerated meats. Thus knowledge of the presence of these fungi in wools is necessary to help avoid problems in public health.
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    The segmental sensory innervation of the skin of the sheep : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Veterinary Science from Massey University
    (Massey University, 1967) Kirk, Edwin James
    The interest in the segmental basis of cutaneous sensory innervation evinced by the ancient Greeks was developed into a major contribution to experimental biology by the studies in man and animals by Sherrington, Head and Foerster. The present study is one of a number of more recent investigations of the dermatomes in animals from which a great deal of comparative information has been obtained. The particular significance of a study of the functional anatomy of the sheep in relation to veterinary medicine has been discussed. The experimental work described in this thesis involved particular consideration of the following 1. The features of the topographical anatomy of the vertebral column of the sheep which were found to be of importance in the experimental procedures. 2. The value of the "remaining sensibility" technique as a means of defining the dermatomes of the sheep. 3. The use of figurines and photographs in the schematic representation of the experimental results. 4. The justification for basing the definition of the dermatomes largely on the responses to pinch stimuli. 5. A discussion of the features of the dermatomes of the sheep in relation to embryological development and the observations which have been made in other species. 6. The changes in muscle tonus in the limbs which followed section of the dorsal spinal nerve roots or damage to the spinal cord. 7. The aberrations in feeding, defecation, micturition and respiration produced by various dorsal root sections. 8. The major pathways in the spinal cord followed by the primary afferent fibres, as revealed by the Marchi technique. 9. A general consideration of the significance of studies such as the present, and their possible extension to include deeper somatic or visceral structures. Details of the dorsal root sections undertaken have been provided in an appendix.
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    Cannon bones : some dimensions, heritabilities and relationships to carcass quality in Romney wether lambs : a thesis presented in partial fulfillment of the requirements for the degree of M. Agr. Sc.
    (Massey University, 1957) Hughes, Alan Herbert
    In the past and to a certain extent at the present time sheep breeders have paid considerable attention to the dimensions of the cannon bones of their animals in the belief that this bone serves as a good indicator of the quality of the conformation and constitution of their animals. Scientific workers interested in meat and carcass quality have also attached considerable importance to the cannon bone as an index of carcass composition and hence of carcass quality. The origin of the sheep breeders beliefs is no doubt due to years of farmer observation supported to some extent by the findings of the scientific workers, who of necessity, using relatively small numbers of animals, have established relationships between the dimensions of the cannon bone and other characters of' economic importance. The existence at Massey Agricultural College of complete records, concerning cannon bone dimensions and carcass quality, collected from a relatively large number of animals, prompted this present study which was intended to yield more accurate results than those previously reported. At the same time this study was designed to yield estimates of the heritability of cannon bone dimensions and their relationship to carcass quality thus providing a basis on which breeders might decide whether or not they could continue to place the present amount of emphasis on the cannon bone in their selection practices .
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    Pasture availability and composition in relation to diet selection and diet quality by grazing sheep : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science at Massey University
    (Massey University, 1979) Guy, Murray Clive
    Some factors influencing grazing behaviour, diet selection and diet quality by sheep were investigated. The influences of pasture availability, accessibility, composition and digestibility on diet selection by grazing sheep at two stocking rates (24 and 36 sheep per hectare) over three-day grazing periods during two seasons (summer and autumn) were examined. The stocking rates were replicated twice and measurements were recorded at six intervals, each a three-day grazing period., over the summer and autumn seasons. Dietary samples were obtained by the use of oesophageal fistulated sheep, and comparisons between extrusa samples and cut pasture were made. Pasture type contrasted between seasons with extremes of availability, structure, accessibility and quality. These evolving pasture types and their changing properties are discussed. Sheep grazing pasture have the ability to be selective, the extent of diet selection being dependent on pasture properties of availability, composition and quality. Diet preference is for the green leaf component of the pasture with avoidance of mature stem and dead matter. However in situations of low pasture availability and poor accessibility of the preferred green leaf component, increasing amounts of dead herbage were ingested, as was evidenced in comparisons between periods and during three-day grazing periods. Digestibility values of the sheeps' diets are higher than corresponding values from available pasture the magnitude of the difference being dependent on pasture composition, availability and accessibility, ie. the opportunity afforded for diet selection.Descriptions of experimental site, climatic conditions and animal management are recorded. The results are discussed in relation to other research findings, and their practical implications.
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    Some aspects of gene dosage effects in N-type sheep : a thesis submitted in part fulfilment of the degree of Master of Science, Massey Agricultural College
    (Massey University, 1952) Stephenson, S K
    A study of gene dosage effects in N-type sheep has been made using the fibre type array method and the medullometer method developed by Elphick and McMahon. As the position was complicated by gradients occuring in the fibre type arrays and total fleece medullation over the body, the study on each sheep was made in the seven positions: back, withers, side, shoulder, shoulder patch, neck and britch, this being to see what gradients were present and how these changed with increasing N-gene dosage.