Effect of various hCG treatment protocols on luteal characteristics, plasma progesterone concentration, and pregnancy in normal cyclic Indian crossbred dairy cows.

Limited information exists on the application of human chorionic gonadotropin (hCG) post insemination in the Indian crossbred dairy cows. This study aimed to evaluate the effect of four hCG administration protocols on luteal characteristics and pregnancy outcomes following artificial insemination (AI). Using block randomization, 50 healthy lactating crossbred cows were allocated in equal numbers (n = 10 cows per group) to receive either 5 mL normal saline (control) or 1500 IU hCG on the day of AI (hGG-0), day 7 post AI (hCG-7), day 14 post AI (hCG-14), or days 0, 7, and 14 post AI (hCG-0,7,14). All cows were scanned using sequential transrectal ultrasound examinations to evaluate primary luteal parameters, development of accessory corpora lutea, and pregnancy. Serial blood samples were collected to measure plasma progesterone concentrations. Data were analyzed using repeated measures ANOVA and Fisher's exact tests. The mean primary luteal area, total luteal area, and total luteal diameter values were significantly greater in the hCG-treated cows. Compared to the control, the hCG-14 group had a significantly higher percentage of cows with an accessory corpora luteum. However, there were no significant differences in the mean progesterone concentrations or the first service conception rates between any of the groups. Overall, the results of this study indicate that while hCG administration post AI in healthy Indian crossbred cows may enhance primary luteal dimensions or induce the formation of accessory corpora lutea, it does not appear to have any beneficial effect on luteal function or pregnancy.

Endometritis Increases Pro-inflammatory Cytokines in Follicular Fluid and Cervico-vaginal Mucus in the Buffalo Cow.

Emerging evidence shows that some of the pro-inflammatory cytokines are elevated not only in the endometrium but also in the follicular fluid of cows with endometritis. Developing a cervico-vaginal mucus (CVM) based test has the potential for becoming a pen-side test because of the ease of sample collection. The present study describes the results of two different experiments. The first experiment was conducted to investigate the influence of endometritis on the proinflammatory cytokines of follicular fluid based on the reproductive tracts of buffalo collected at a slaughter house Buffalo genitalia were categorized into purulent endometritis (PE), cytological endometritis (CE), and non-endometritis (NE) based on the white-side test and endometrial cytology, respectively (n = 14/group). Each group was subdivided into follicular and mid-luteal stage (n = 7/stage) and the follicular fluid was collected from the largest follicle. Second experiment was done to study the difference in the levels of proinflammatory cytokines in the CVM of repeat breeders with subclinical endometritis presented to the clinic. CVM was collected from the repeaters (n = 10) and non-repeaters (n = 10) through aseptic trans-vaginal aspiration. The pro-inflammatory cytokines such as IL-1ß, IL-6, IL-8, and TNFα were quantitated through bovine specific ELISA kits. Significantly higher concentrations of pro-inflammatory cytokines (IL-1ß, IL-8, IL-6, and TNFα) along with low intra-follicular estradiol in buffaloes of PE and CE groups suggest that endometritis impedes the follicular steroidogenesis. Significantly higher concentration of IL-1ß and TNF-α in the CVM of repeaters indicate their potential as a pen-side diagnostic test for CE.

Effect of L-arginine methyl ester (L-NAME) on hormonal profile and estrous cycle length in buffaloes (Bubalus bubalis).

The present study was undertaken to evaluate the effect of L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor on serum nitric oxide, progesterone, estradiol profiles and estrous cycle length in buffaloes. Murrah buffaloes (n = 16) exhibiting regular estrous cycles were randomly allocated to two groups of eight animals. In the treatment group, buffaloes were administered 400 mg/h L-NAME over 2 h (total dose = 800 mg) via the coccygeal artery and the aorta abdominalis on day 15 of the estrous cycle. In the control group, normal saline was infused on the same day of the cycle by the same route. Blood samples were collected every 4 h on days 15 and 16, and once daily from days 17 to 21 of the estrous cycle for the assay of progesterone, estradiol and nitric oxide. L-NAME treatment significantly (p < 0.05) reduced serum nitric oxide concentration from 4 h of day 15 until day 20 of the cycle. Serum progesterone concentration increased significantly (p < 0.05) between 0 and 20 h post treatment on day 15. The estrous cycle length was 19.8 ± 0.36 and 23.6 ± 0.17 days for control and treated group buffalo (p < 0.05), respectively. It was concluded that treatment of buffalo with L-NAME in the late luteal phase of the estrous cycle inhibited serum nitric oxide concentration resulting in increased progesterone production and extension of the effective life of the corpus luteum, thus prolonging the estrous cycle length.