In vitro maturation of class I oocytes of bovine during different tropical seasons.

The aims of this study were to determine the effects of seasonality on yields and quality of bovine abattoir-derived oocytes and their in vitro maturation (IVM) competence in Thailand, a tropical country. Ovaries were collected monthly from a slaughterhouse, from January to June 2017, separated into cool (January to February), summer (March to April), and rainy (May to June) seasons. Cumulus oocyte complexes (COCs) were obtained by follicular aspiration, and subsequently, oocyte yield and quality were examined. Selected class I and II COCs were cultured under IVM condition, and their maturation capacity was also evaluated. Results showed that average numbers of COCs and class I COCs per ovary were highest in summer. However, no significant seasonal difference in oocyte maturation rates was found. The higher numbers of COCs and class I COCs in summer might be caused by their follicular development during the cool season, and might be a reason why the pregnancy rate in summer is better than in the rainy season.

Phenotypic characteristics of feline adipose-derived stem cells affected by cell passage number.

In this study we evaluated the influence of passage number on the phenotypic characteristics of feline adipose-derived stem cells (ASCs) in order to develop a broader understanding of their dynamics. Feline ASCs were individually isolated from five domestic cats and subjected to proliferative culture at passage (P) 2, 6 and 10. The cells at each sub-passage were examined in regard to their phenotypic properties associated with multipotent mesenchymal stem cells (MSCs), such as morphology, proliferation kinetics, self-renewal, and expression of MSCs-specific surface markers. The differentiation capacity into adipocytes and osteoblasts was also identified. Feline ASCs appeared with a fibroblast-like morphology with minimal alteration through P10. The rate of cell proliferation gradually decreased, while cell doubling time gradually increased with each passage. A significant decrease in CFU-F efficiency was observed with increasing cell passage number. The ASC population uniformly expressed their characteristic markers CD44 and CD90, but did not express the hematopoietic marker CD45. However, MSC markers gradually decreased in the later passage stages. Feline ASCs were capable of undergoing both adipogenesis and osteogenesis at P2. These findings suggested that the phenotypic characteristics of feline ASCs could be affected by long-term passages, which is potentially very important in regard to their therapeutic application.

Postpartum ovarian activity and serum estradiol-17beta level in Thai crossbred native mares.

To study the postpartum ovarian activities for investigation of first postpartum oestrus, twenty-five Thai crossbred native mares were monitored after parturition by oestrous detection, transrectal palpation and reproductive ultrasonography. Blood samplings were also taken for estradiol-17beta (E2) analysis. The first ovulation occurred within 20 days postpartum in 92% (23/25) of the mares. The mean intervals of foaling to first oestrus and to first ovulation were 10.3 +/- 2.9 and 13.4 +/- 2.6 days (mean +/- SD) respectively. Serum E2 increased from 7.0 +/- 2.9 to a peak of 10.8 +/- 3.3 pg/ml (mean +/- SD) at 2 days before ovulation. In conclusion, from the study, it can be stated that the postpartum breeding management should be considered after day 10 postpartum by careful examination of ovarian activity with various methods. However, the uterine condition should be also estimated associated with the ovarian activity after parturition which may increase breeding performance and foal production.