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Item Studies of the coat of the Romney lamb : practical and theoretical aspects of hair morphology, with special reference to the evolution of the fleece : thesis submitted by "Bourn" [for the degree of Master of Agricultural Science](Massey University, 1940) Goot, HenryThe original purpose of the present thesis was to answer this question: "To what extent is a britch of high halo-hair abundance an indicator of the non-kemp hairiness of the fleece?" It was assumed by Dr Dry in the light of earlier observations, that, on a britch with very many halo-hairs, the large Curly Tip fibres would be very hairy, and this has proved to be so. Especially did we want to learn about the degree of hairiness on the part of the fleece near to the britch. The gradient over the body from the britch was also much in mind, all the more because the boundary between the area on the britch with very many halo hairs and the neighbouring region with far fewer halo hairs is often abrupt. The aim of the work was that just defined, but the analysis of the samples examined provided information on a number of other matters, several of which may be thought more interesting than the problem proposed at the outset. These various results are reported in this thesis.Item Space and time relations in the coat of the New Zealand Romney lamb(Massey University, 1943) Galpin, Nancy MIn a recent paper Dry (4) gives an account of the fibre type arrays - the result of an action of two forces - the prenatal check and the reducing of inherent coarseness acting on an undefined substratum which occur on the back (4) of the New Zealand Romney Lamb. Preliminary observations by Dr. Dry and myself suggested that orderly relations existed between the fibre type arrays on the back and britch positions. These observations were extended and a comparative study of the fibre type arrays occurring over the dorsal and dorso-lateral portions of the coat of the Romney Lamb has been made. Their distribution, as one was prepared to find, has proved orderly. Following naturally on this investigation came a study of the proportions of precurly-tip to curly-tip and histerotrich fibres.Item A study of the effects of undernutrition and re-alimentation on the Romney ewe : 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) Hight, G. K.No abstract.Item A study of some effects of progesterone and pregnant mares' serum (PMS) on reproductive phenomena in the anoestrous Romney ewe : a thesis presented at Massey Agricultural College in part fulfilment of the requirements for the degree of Master of Agricultural Science in the University of New Zealand(Massey University, 1955) Lamond, D. R.No abstract.Item A study of the ovarian response of New Zealand Romney ewes sequentially superovulated with pregnant mare's serum gonadotrophin : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Science at Massey University(Massey University, 1973) Clarke, Iain JamesA series of experiments investigated the nature and causes of ovarian refractoriness in ewes sequentially treated with Pregnant Mare's Serum Gonadotrophin (P.M.S.G.). 70 ewes were subjected to the following treatments over 3 oestrous cycles of the 1972 breeding season:- 1. Injectcd with P.M.S.G. at each of 3 cycles (cycles 1,2 and 3); 2. Two injections of P.M.S.G. (at cycles 1 and 3) separated by a nornal oestrous cycle; 3. Injected with P.M.S.G. at two successive cycles (cycles 2 and 3); 4. Injected at 1 cycle only (cycle 3). These treatments were replicated at 1000 i.u. and 1500 i.u. P.M.S.G. and 9 ewes acted as an uninjected control group. The ewes were blood sampled and slaughtered at the end of these treatments and ovulation data were obtained by recovery of the reproductive tracts. The terminal ovulation rates showed that ewes were refractory to a second injection of P.M.S.G. and this condition persisted. The refractoriness was to some extent alleviated by the spacing of injections (Treatment 2 above). Biological Inhibition Tests (using mice) analysed the plasma of the above ewes for evidence of anti-gonadotrophins. Although such factors were not detected in the blood of these ewes, the test did reveal antibody production against P.M.S.G. in the plasma of a further group of ewes which had been chronically treated with the hormone for 6 weeks. It was concluded that ovarian refractoriness, which is rapidly attained in sequentially treated ewes, is not due to the development of serological antibodies against the exogenous gonadotrophin. Another experiment, carried out early in the 1973 breeding season, investigated ovarian follicle development in 30 owes whlch were sequentially treated with P.M.S.G. for up to 3 oestrous cycles. Ewes were laparotomised or killed on Day 10 of the oestrous cycles following treatment and measurements on follicle development were taken. A group of control ewes were observed at a similar time to the treated ewes. Counts on ovarian surface follicles dlffered litt1e between treated and control ewes, at each of the observations. However, the ovaries of slaughtered ewes were sectioned to allow estimation of total ovarian follicular populations and to make some assessment of follicular atresia. Ewes slaughtered after 1 injection of P.M.S.G. had lower numbers of normal antral follicles per ovary than did control ewes or ewes observed at similar times after 2 or 3 injections. It was suggested that exhaustion of ovarian follicular populations may precipitate a refractory condition but that this condition persists because of an endogenous hormonal imbalance. Further work should be done to investigate this latter possibility.Item A study of some aspects of selection for the fertility of New Zealand Romney ewes : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science(Massey University, 1963) Clarke, J. N.No abstractItem A study of some aspects of reproduction in Romney and Romney-Cheviot halfbred two-tooth ewes : being a thesis presented in partial fulfillment of the requirements for the degree of M. Agr. Sc., Massey Agricultural College, University of New Zealand(Massey University, 1953) Inkster, I. J.No abstractItem A comparative study of the effect of two stocking levels on wool follicle development and wool production of the New Zealand Romney sheep : a thesis presented in partial fulfilment of the requirement for the degree of Master of Agricultural Science in Animal Science at Massey University(Massey University, 1969) Sumner, R. M. W.No abstractItem Studies on the testicular development of the New Zealand romney ram : a thesis presented in partial fulfilment of the requirements for the degree of Master of Veterinary Science at Massey University(Massey University, 1971) Steffert, Ian JamesThe growth of 33 N.Z. Romney rams was observed between birth and 269 days of age. The weight And histology of the testes of these lambs were studied And compared with the histological charges of the testes in 44 foetuses between the ages of 42 days and birth. Testis growth changed sharply to a faster rate, from 70 days of age when the body weight exceeded 20 kilograms. This change in growth rate was associated with the commencement of apermatogenesis. The completion of the first cycle of apermatogenesis was dependent on the attainment of a testis sise of 34 grams in a ram at least 22 weeks of age. Changes in tto epithelium and boundary tissue of the sex cords and seminiferous tubules wero closely related to the different phases of testes' growth. The sex cords were present in the testis of the 42-day foetal lamb, but did not show a definite boundary tissue until 53 days of foetal life. Little variation in their development was apparent until the onset of spermatogenesis. The transition from sex cords to seminiferous tubules followed a greater rate of increase in tubular diameter. The gonocytes which were more centrally placed in the sex cords than the nuclei of the supporting cells, became transformed into prospermatogonia before their evolution to adult stem cells at the boundary tissue. Lumen formation in the seminiferous tubule was concomitant with the completion of Sertoli cell development and the appearance of the more advanced forms of germ cells. At birth tha boundary tissue consisted of a non-cellular layer, which had reached its widest margins, and an outer multi-cellular layer of fibroblast-like cells. Differentiation of the four component tissues in the mature tubular wall, the inner non-cellular layer, the inner cellular layer, the outer non-cellular layer and the outer cellular layers, became apparent about the time spermatogenesis commenced, and appeared to be fully developed when the first cycle of spermatogenesis was completed. The inner non-cellular layer became thinner as the outer non-cellular layer became evident. Throughout their developmental phases fibres of elastic tissue were dispersed evenly within the two non-cellular layers. During puberty increases to adult proportions were most rapid in the outer non-cellular layer. The significance of elastin in the boundary tissue of the seminiferous tubules in the ram could not be determined. The density of the elastin component as a measure to Indicate the degree of immaturity of the testis of a ram was postulated.Item Body composition studies on the Romney ewe : a thesis presented in partial fulfilment of the requirements for the degree, Master of Agricultural Science in the University of New Zealand(Massey University, 1960) Ulyatt, M. J.No abstract