This review emphasizes the fundamental aspects of follicle development and also the usefulness of reproductive hormones and some clinical applications for manipulation of oestrous cycle, oestrus behavior and the ovulation rate in mares.

The aim of this study was to compare morphological and functional features of spontaneous and induced corpora lutea (CLs) in goats. Fourteen adult and cycling Anglo Nubian goats (Argentina) were randomly allocated to two groups: Group N (n=7) included goats with natural spontaneous oestrus and Group PG (n=7) included does in which oestrus was synchronized by the administration of two i.m. clopr...

A total of 415 fat tailed ewes were randomly assigned to two groups to assess the effect of duration of melengestrol acetate (MGA) (9 versus 12d) administration on reproductive parameters associated with laparoscopic artificial insemination. At the end of MGA treatment, ewes in each group were subdivided and inseminated with one of two different insemination doses (10×10(7) or 20×10(7) sperm pe...

The study was conducted on 30 true acyclic Sahiwal cows (15 cows, ≥90 days postpartum; 15 postpubertal heifers, ≥30 months of age) and a similar 20 untreated controls (10 cows, 10 heifers). An ‘Eazi’ breed Controlled Internal Drug Release (CIDR) device (containing 1.38 g progesterone) was inserted intravaginally for 7 days (days 0 to 7) followed by 500 IU eCG i.m. at CIDR removal in all the tre...

The jill is a long-day breeder with a constant oestrus without mating. Persistent oestrogen production results in clinical signs of hyperoestrogenism including pancytopenia and death if untreated. As spaying is thought to be related to the development of hyperadrenocorticism, a non-invasive, safe and effective long-term treatment is needed for oestrus suppression in jills. Seven jills in oestru...

The buffalo is an important livestock resource in several countries of South Asia and the Mediterranean regions. However, reproductive efficiency is compromised due to known problems of biological and management origins, such as lack of animal selection and poor nutrition. Under optimal conditions puberty is attained at 15 to 18 months in river buffalo, 21 to 24 months in swamp buffalo and is i...

We are maintaining two obese mutant rat strains (WNIN/Ob and WNIN/GR-Ob) in our animal facility since 1997. These rat colonies are perpetuated by crossing heterozygous littermates, since the obese phenotypes of both genders turned out be infertile. The present study revealed the reasons for this infertility. The male obese rats, though appeared normal in terms of sperm count, sperm motility and...

The pattern of vaginal cell exfoliation during the oestrous cycle period was studied in cycling and non-descript West African dwarf (WAD) goats. The exfoliated epithelial cells were categorised into parabasal, intermediate and superficial and their relative occurrences were used to determine the reproductive status of the cycling and non-descript does. The mean cell counts of the epithelial and...

Changes in endogenous prolactin levels in rats with age and after ovariectomy varied according to the reproductive state, emphasizing the different mechanisms underlying infertility in rats in constant oestrus and prolonged dioestrus.