A significant proportion of potential lambs are lost (commonly 15-20%) between ovulation and day 30 of gestation. Moreover, little is known about factors associated with multiple birth capacity of the uterus which would be necessary to convert gains in ovulation rate to the birth of live lambs. This project has investigated the relationship between maternal uterine and hormonal environment as well as the heritability of embryonic survival (ES) in prolific ewes. Litter size (LS) from known ovulation rate (OR) records (n=6393) collected over 16 years were analysed for heritability. ASReml analysis reported ES to be a trait of low repeatability (r� = 0.103) and heritability (h� = 0.04) which is consistent with earlier studies of this trait. However, pedigrees of outlier animals indicated a segregation pattern consistent with a single autosomal gene with a major affect on enhanced ES. From this flock, closely related high ovulation rate ewes with significantly different litter sizes (High ES; OR2.6/LS2.4 versus Low ES; OR2.9/LS1.6) were selected for further study. The anatomy and gene expression of the uterus collected at day 14 of the oestrous cycle (n=5 High and n=5 Low ES ewes) and day 16 of gestation (n=14 high and n=10 Low ES ewes) as well as systemic concentrations of hormones indicative of uterine (activin-A, follistatin) and ovarian (inhibin-α, progesterone) function during the oestrous cycle and early gestation were compared. Progesterone concentrations were found to rise earlier in high ES ewes with a difference in number of ewes with detectable levels of progesterone apparent by day 4 of gestation. The peak concentration and slope of progesterone increase as well as plasma profiles of oestradiol and inhibin-α were not different between groups. A number of pathways worthy of closer investigation were implicated by microarray analysis with Ingenuity Pathway Analysis, Pubmatrix, and candidate gene approaches. In particular, the altered expression of many immune cell factors suggests that high ES ewes have maternal gene expression of the inflammatory pathways favourable to embryo implantation. The plasma concentration of activin, but not follistatin, was found to be significantly higher in low ES ewes, a difference that remained apparent when the concentration of follistatin was corrected for individual samples. Furthermore, the concentration of activin, but not follistatin, was significantly elevated on day 16 of gestation in the uterine fluid of low ES ewes. Further investigation of the pattern of gene expression during the oestrous cycle and early gestation (day10-16 oestrus and days10-20 gestation) revealed that a significant increase in follistatin mRNA in the luminal epithelia and interacting trophoblast cells of the embryo occurs on day 18 and 20 of gestation. It is likely the appropriate balance between activin and follistatin during the time of implantation enhances embryonic survival in this line of ewes. This may be secondary to or concomitant with the observed earlier rise in progesterone concentration. The implication that embryo survival may be positively influenced by a single autosomal gene has important implications for New Zealand's agricultural industry.

Bibliography: leaves 336-365. / xx, 365 leaves : ill., maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geography, 1995

Errata sheet inserted on front fly-leaf. / Bibliography: leaves 326-357. / xxii, 357 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study investigates the causes of change in determinants of fertility regulation and behaviour among women in the city of Kathmandu, Nepal. The research uses data collected in fieldwork in Kathmandu between November 1991 and May 1992. To explore different mechanisms causing change in fertility behaviour, a conceptual framework modified from Freedman (1987) is adopted. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geography, 1995?

Typescript (photocopy) / Includes bibliographical references (leaves 198-259) / xvi, 259 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The role of gonadal steroids in the mating behaviour of rams was investigated in both entire rams and castrated rams (wethers) treated with different steroids. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences,1983

In Australia, high local densities of macropodid marsupials in state parks, nature reserves and wildlife sanctuaries are threatening biodiversity and pose a considerable management challenge. The high public profile of these species places socio-political constraints on the management options available. The use of fertility control techniques appears to offer an alternative. However, before a contraceptive system can be developed a detailed knowledge of the reproductive processes for that species must be generated. In this thesis, sexual maturity, seasonal reproduction, aspects of the endocrinology of reproduction and fertility control were investigated in the eastern grey kangaroo. In Victoria the eastern grey kangaroo is capable of breeding at all times of the year, although breeding is more synchronous than in northern populations, with 41% of the females breeding between December and January. In Victorian populations the onset of sexual maturity is delayed in both sexes, with females reaching maturity at 22 ± 1.2months and some males not reaching sexual maturity by 32 months of age. Male kangaroos showed seasonal changes that closely tracked the reproductive activity of the female kangaroos. Plasma testosterone concentrations were significantly elevated during the peak breeding period compared to all other times of the year. Both prostate and testis weights were low during winter when the reproductive activity of the females is low, although the difference was not significant.

A very high proportion of beef cows in Australia are mated to bulls at pasture. A multiplicity of systems for pasture mating are presently in use. Bulls are mated singly or in groups, they are set-stocked during the mating period or rotated about the different groups of cows, they are mated at the rate of 2, 3, 4, 5 or 6 bulls per 100 cows, young bulls are mated to cows in company with old bulls or other young bulls (Dickson 1966). There is little scientific basis for any of these mating systems since basic information on the sexual and social behaviour of beef bulls at pasture is lacking. Such data are needed so that optimum use can be made of beef bulls in pasture mating. (For complete abstract open document)

Typescript (photocopy) / Includes bibliographical references (leaves 198-259) / xvi, 259 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The role of gonadal steroids in the mating behaviour of rams was investigated in both entire rams and castrated rams (wethers) treated with different steroids. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences,1983

Thesis (Ph. D.)--University of Adelaide, 1985. / Includes bibliographical references (leaves 182-210).

Lic.-avh. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 2 uppsatser.

Thesis (Ph.D.) -- University of Adelaide, School of Social Sciences, Discipline of Geographical and Environmental Studies and Discipline of Gender and Labour Studies, 2006. / "January 2006" Bibliography: leaves 336-375.