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    The influence of selection for greasy fleece weight on the components of fleece weight in Romney sheep : a thesis presented in partial fulfillment of the requirements for the degree of Master of Animal Science at Massey University
    (Massey University, 1991) Liu, Ai Hua
    Variation in the clean fleece weight (W) of New Zealand Romney sheep was related to variation in its four components: smooth body surface area (S), mean number of fibres (follicles) per unit area of skin (N), mean fibre cross-sectional area(A) and mean fibre length (L). The influence of the combined components, wool weight per unit area, fibre volume and total number of fibres (follicles) was considered. The contribution of the components to differences in fleece weight between the Massey fleece weight selected and control flocks was analysed using the "percentage deviation" technique. L was the most important contributor to fleece weight differences. The components of A and N were about equally important in contributing to between flock differences in fleece weight. By contrast, the contribution of S was relatively small. Wool weight per unit area had far more influence on fleece weight than body surface area (about 84% : 16%). Also, fibre volume made a greater contribution to between flock differences than the total fibre number. Attempts were also made to assess the relative importance of the components of fleece weight between ewes within each flock using either simple linear regression or multiple regression (standardized partial regression coefficients) techniques. Within both the selected and control flocks, A and S appeared relatively more important than between flocks, whereas, the L appeared to be less important, but the L seemed more important within the selected flock than within the control flock in determining the phenotypic differences in fleece weight between sheep.
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    A study of some aspects of the genetic variation and covariation of fertility in a flock of New Zealand Romney ewes : being a thesis presented in partial fulfilment of the requirements for the degree of M.Agr.Sc, Massey Agricultural College, University of New Zealand, May 1955
    (Massey University, 1955) Ch'ang, Tang Seng
    "Fertility" is a term generally used to denote the expression of reproductive performance. Any precise definition of "Fertility", however, must depend ultimately on the purpose for which it is intended and the criterion by which it is measured. For the present purpose "Fertility" may be regarded as the rate of reproduction which is measured by some form of a lambing percentage. The economic importance of fertility in sheep production has not been, until recently, fully appreciated, but still less has its significance in the genetic improvement of sheep been realised. [FROM INTRODUCTION]
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    Space and time relations in the coat of the New Zealand Romney lamb
    (Massey University, 1943) Galpin, Nancy M
    In 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.
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    A study of the plateau array : thesis concerning subsection (e), 608 of the Animal Husbandry Section of the Master of Agricultural Science Degree and incorporating work carried out during the tenure of the Farmers' Union Research Scholarship and the Shell Scholarship1938
    (Massey University, 1939) Sutherland, J. A. (James Alan)
    A brief historical survey of the work leading up to the present study. The world sheep population is in the vicinity of seven hundred millions and the vast majority of these animals are kept, to a greater or a lesser degree, for their wool. It is, therefore, not surprising that Wool Research is by no means new. The production of sheep for their coat has been, as Barker points out ( 1), of importance since Biblical times and, although during the last epoch, with the perfection of methods for meat preservation, the importance of wool to the sheep industry has decreased, the need for wool research has been increased by the ever growing perfection of synthetic fibres. Wool research as such can possibly be dated from Dr. Hook who, in 1664, presented a paper to the Royal Society on the subject of wool and hair structure, but it was not until the advent of the compound microscope that the study of wool gained sufficient precision for measurements to be made. Such measurements opened the door for the wool physicist who, by the application of x-rays and other physical methods, has been able to explore with considerable success the ultimate structure of wool and hair. The value of wool has been determined, at least partially, by its length and thickness (or width), and thus measurements of wool in three dimensions have been important sections of wool research. As other valuable characters were recognised and evaluated they also were measured and correlations worked out. Thus it has come about that wool research has collected about itself innumerable patient measurements - measurements that have often merely evidenced the complexity of the fleece of the sheep as a subject of research.
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    The effect of genetic selection for fleece weight on urea metabolism and digestive function in Romney sheep: 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, 1987) Thomson, Beverley Carol
    The study was undertaken to investigate the effect of 30 years selection for greasy fleece weight on rumen metabolism, apparent digestibility and nitrogen metabolism in the NZ Romney sheep. Previous studies had recorded a lower plasma urea concentration in the fleece weight selected (Fwt) animals as compared to the randomly selected control (C) animals, so most emphasis was placed on determining whether the lower plasma urea concentration in the Fwt sheep was accompanied by a lower irreversible loss (IRL) . Eight C and eight Fwt yearling rams (mean liveweight 42kg) were housed inside in individual metabolism crates. The study was divided into two almost identical experiments - the first one when the animals were fed on a chaffed meadow hay diet and the second on a lucerne chaff diet. Each experiment consisted of a two week adaptation period, a ten day digestibility period and a final period of six days during which 14c-urea was infused intravenously for fourteen hours. At the end of the lucerne chaff experiment the animals were slaughtered and the rumen contents weighed and subsampled. The Fwt animals had a one mM lower plasma urea concentration when fed on both diets. However there was no difference in the plasma urea IRL, urinary urea excretion or urea recycling to the digestive tract between the Fwt and C sheep when fed on either diet. Relative to the C sheep, the Fwt animals had a higher creatinine clearance rate (63 vs 50 ml/min; P<0.05) when fed the meadow hay diet, and a higher urea clearance rate when fed both diets (meadow hay diet 42 vs 32 ml/min, P<0.10; lucerne chaff diet 72 vs 60 ml/min, P<0.05). When fed the meadow hay diet there were no differences between the Fwt and C animals in voluntary feed intake (VFI) (Fwt animals 44 vs 42 gDM/kgw0 · 75;d C animals) or apparent digestibility (DM digestibility 55% for both genotypes). However when fed on the lucerne chaff diet the Fwt animals had a higher VFI than the C animals (102 vs 94 gDM/kgw0 · 75 /d) and a lower apparent dry matter digestibility (56.1% VS 61.3%; P<0.05). These changes were associated with an increase in the rumen Fractional Outflow Rate (FOR) of lignin in the Fwt sheep (3.00 vs 2.58 %/h; P<0.05). There was a higher molar proportion of acetate present in the rumen fluid of the Fwt animals than in the C animals (68.6 vs 64.0%; P<0.10). These results confirm that the Fwt animals have a consistently lower plasma urea concentration over a range of nutritional levels (0.6X maintenance and 1.5X maintenance) than the C animals, but there was no difference in urea metabolism as measured by plasma urea IRL and urea excretion. The urea and creatinine clearance rates suggest that selection for fleece production may have altered kidney function, but that the expression of these differences is related to the nutritional level. The greater FOR in Fwt sheep fed at the high level of nutrition (i.e. lucerne chaff) may mean that the amino acid flow at the duodenum (undegraded dietary plus microbial protein) is greater than in the C animals and this could be a factor contributing to the superior wool production of the Fwt sheep.
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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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    Investigations into some effects of cysteine administration to the New Zealand Romney : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Scienc
    (Massey University, 1968) Dryden, Gordon McLean
    The Present Work: Up to this date, all sulphur containing amino-acid and protein infusion work had been done in Australia using Australian Merinos. It was decided to conduct a similar experiment to see whether cysteine infusion had a similar effect on the wool grovvth rate of New Zealand Romneys. The work described in this thesis consists of two parts:- (i) a preliminary experiment was conducted to see if the Romney wool growth rate responded to cysteine infusion, and if so, at what dose levels. A first investigation of the wool factors involved was also made. (ii) having found that the Romney did respond to cysteine treatment a second experiment was carried out to determine more exactly the wool factors involved in the response and to see if the response was altered by the protein content of the basal diet. The effect of cysteine administration on the digestibility of basal diet was also examined. [From the Introduction]
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    Genotype-environment interactions and genetic parameters in New Zealand Romney sheep : a thesis submitted for the degree of Doctor of Philosophy at Massey University, New Zealand
    (Massey University, 1978) Chopra, Subhash Chander
    Performance records of 1,113 New Zealand Romney ewe hoggets from two subflocks maintained on control (CSR) and intensive (HSR) stocking rates were analysed. The data represented the progeny of 34 sires and were collected between 1967 and 1974 inclusive which covered four consecutive two-year sire periods. The traits investigated were hogget live-weight (HLW), greasy fleece weight (GFW), clean wool weight per unit area (WA), clean scoured yield (Y), staple length (SL), mean fibre diameter (MFD), standard deviation of the fibre diameter (SFD), quality number (QN), crimps per centimeter (CPC), total crimp number (TCN), character (CHG), tippiness (TG), handle (HG), lustre (LG), greasy colour (GCG), scoured colour (SCG), discoloured area (DAG), cotting (CG), cotted area (CAG) and soundness (SG). Stocking rate had significant effect on all the traits excepting MFD, SFD, TCN and HC. HSR depressed the traits investigated excepting Y, SFP, QN, CPC, HG, GCG, SCG, CG and CAG. Year effects except in DAG were an important source of variation. The influence of birth-rank except on HLW, SFD, CHG and HG was small. Stocking rate x year interactions except in CPC, TCN, CHG, TG, HG, GCG and CAG were important. Sire x stocking rate interactions were significant in HLW, MFD, SFD, TCN and GCG only, whereas sire x year interactions were significant in HLW, GFW, HG and SCG. Sire x stocking rate and sire x year interactions were included in different ways in some formulae for calculation of heritability estimates. These estimates were calculated from paternal half-sib analyses in CSR, HSR and combined data. The various estimates for the different traits were in the following ranges:- HLW 0.21 - 0.72, GFW 0.38 - 0.61, WA 0.31 - 0.49, Y 0.19 - 0.53, SL 0.54 - 0.63, MFD 0.34 - 0.87, SFD 0.35 - 0.66, QN 0.46 - 0.72, CPC 0.48 - 0.88, TCN 0.65 - 1.09, CHG 0.24 - 0.34, TG 0.13 - 0.27, HG 0.23 - 0.66, LG 0.32 - 0.42, GCG 0.22 - 0.44, SCG 0.10 - 0.39, DAG 0.04 - 0.21, CG 0.12 - 0.67, CAG 0.13 - 0.53, SG 0.00 - 0.22. No significant differences between the estimates in the two stocking rates except in CG and SG were observed. The relevance of these comparisons is discussed in terms of sire x stocking rate and sire x year interactions. Intra-trait genetic correlations between the two stocking rates were close to unity except in HLW (P<0.05); Y, SFD, GCG, SCG (0.05