Increased luteal tissues after secondary corpus luteum formation leads to enhanced progesterone concentrations and improved fertility in repeat-breeder dairy cows during heat stress condition in tropical climate
BackgroundRepeat‐breeder cows repeatedly fail to conceive after at least three attempts and return to oestrus at apparently normal intervals. Repeat‐breeder cows cause economic losses in dairy farms in different ways.ObjectiveIn the present study, we investigated the effect of sustained‐release progesterone injection in two different doses on the expression of interferon‐related genes in repeat‐breeder dairy cows.MethodsA total of 96 repeat‐breeder primiparous and multiparous cows were assigned among three groups: control group, inseminated and do not receive progesterone treatment; P400 and P600 groups, inseminated and received a single‐intramuscular injection of 400 and 600 mg slow‐release progesterone 5 days after insemination, respectively. Blood sampling was carried out on Day 20 after AI for progesterone measurement and evaluation of gene expression for ISG15, MX1 and MX2 genes.ResultsOne injection of sustained‐release progesterone increased the expression of ISG15, MX1 and MX2 genes with differences between two different progesterone concentrations. For all three genes, the level of gene expression was higher in progesterone‐supplemented group than in control group, when P400 and P600 groups considered together. The level of MX2 gene expression was significantly higher in pregnant cows than non‐pregnant cows. There was a significant positive correlation between expression level of all three genes and blood progesterone concentration. The expression level of ISG15 gene showed a significant positive correlation with MX1 and MX2 gene expression.ConclusionThe use of this sustained‐release progesterone is simple and can be used in repeat‐breeder cows to improve fertility.
BackgroundRepeat‐breeder cows repeatedly fail to conceive after at least three attempts and return to oestrus at apparently normal intervals. Repeat‐breeder cows cause economic losses in dairy farms in different ways.ObjectiveIn the present study, we investigated the effect of sustained‐release progesterone injection in two different doses on the expression of interferon‐related genes in repeat‐breeder dairy cows.MethodsA total of 96 repeat‐breeder primiparous and multiparous cows were assigned among three groups: control group, inseminated and do not receive progesterone treatment; P400 and P600 groups, inseminated and received a single‐intramuscular injection of 400 and 600 mg slow‐release progesterone 5 days after insemination, respectively. Blood sampling was carried out on Day 20 after AI for progesterone measurement and evaluation of gene expression for ISG15, MX1 and MX2 genes.ResultsOne injection of sustained‐release progesterone increased the expression of ISG15, MX1 and MX2 genes with differences between two different progesterone concentrations. For all three genes, the level of gene expression was higher in progesterone‐supplemented group than in control group, when P400 and P600 groups considered together. The level of MX2 gene expression was significantly higher in pregnant cows than non‐pregnant cows. There was a significant positive correlation between expression level of all three genes and blood progesterone concentration. The expression level of ISG15 gene showed a significant positive correlation with MX1 and MX2 gene expression.ConclusionThe use of this sustained‐release progesterone is simple and can be used in repeat‐breeder cows to improve fertility.
The objective of the present study was to investigate the association among the largest follicle (LF), preovulatory estradiol (E2), and predominant vaginal epithelial cell at the completion of hormonal ovarian stimulation for fixed‐time artificial insemination (FTAI) in goats. Thirty‐seven crossbred Boer does received gonadotropin‐releasing hormone (GnRH) and intravaginal progesterone (P4)‐releasing devices (day 0). On day 5, P4 devices were removed and does received prostaglandin F2α and equine chorionic gonadotrophin. On day 7, does received GnRH, and FTAI was undertaken. On day 7, does were divided into three groups, i.e. small‐sized (3–3.9 mm; n = 5), medium‐sized (4–4.9 mm; n = 8), and large‐sized (≥5 mm; n = 24) according to the diameter of the ovarian LF; follicular characteristics (number and diameter) were identified, and blood samples and vaginal smears were collected. The average diameters of total antral follicles and LF and the percentage of superficial cell were greatest in large‐sized LF does (p < .01). The average diameters of total antral follicle (r = .68) and LF (r = .71), number of preovulatory follicle (r = .58), and plasma E2 concentrations (r = .61) were positively correlated with the percentage of superficial cells (p < .01). The likelihood of a pregnancy outcome after the FTAI increased by 13.71 times in does with a greater average diameter of antral follicle, 14.18 times with emergence of a large preovulatory follicle, and 36.83 times with a higher percentage of vaginal superficial cells (p < .01). It was concluded that there is a relationship between the cell types of the vaginal epithelium, the diameters of the largest ovarian follicles, and the concentration of E2 in goats subjected to FTAI protocols.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.