A 2-sample regime was used to measure whole milk progesterone concentration on the day of oestrus and insemination (Day 0) and 6 days later (Day 6) in a sample of 50 primiparous and 100 multiparous suckling beef cows. Exposure to teaser bulls and observation by cattlemen identified the occurrence of oestrus. Three sets of criteria used to define ovulatory oestrus were compared: a) milk progeste...

Up to 50% of ovulations go undetected in modern dairy herds due to attenuated oestrus behavior and a lack of high-accuracy methods for detection of fertile oestrus. This significantly reduces overall herd productivity and constitutes a high economic burden to the dairy industry. MicroRNAs (miRNAs) are ubiquitous regulators of gene expression during both health and disease and they have been sho...

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.

UNLABELLED Our aim was to compare Corpus luteum (CL) development and blood plasma concentration of progesterone ([P4]) in thoroughbred mares after spontaneous ( CONTROL C) or human chorionic gonadotrophin (hCG)-induced ovulation. Lactating mares (C=12; hCG=21) were daily teased and mated during second oestrus post-partum. Treated mares received 2500 IU hCG i.v. at first day of behavioural oes...