Intravenous glucose enhanced some reproductive hormones, superovulation success and the number of transferable embryos in postpartum holstein dairy cows

Insufficient energy negatively impacts metabolites and hormones involved in embryo production success. This study investigates the effects of intravenous (IV) glucose administration on some metabolites and hormone levels that influence follicle development, superovulation success, and transferable embryo production. Fourteen lactating Holstein cows (3–5 years old; body condition score: 3.0–3.5), with hematological parameters (e.g., white blood cell and neutrophil counts) within the reference ranges, in early lactation (60–80 days postpartum) and in their first or second lactation were enrolled. Experimental group (E; n = 7) received 150–200 (depending on live weight) mL of 5% dextrose intravenously approximately 5 min before intramuscular (IM) Follicle Stimulating Hormone (FSH) administration (Day 7) for four days, whereas the control group (C; n = 7) did not. Initially, blood samples were collected on Day 6, one day before the IV glucose and IM FSH administrations to assess any differences, and there were not any differences between the groups ( P > 0.05). During the treatments, blood samples were collected before and at 2-hour intervals following each IV glucose and IM FSH administrations. Plasma concentrations of glucose, non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), FSH, leptin (LEPT), estradiol (E 2 ), and insulin-like growth factor-1 (IGF1) were analyzed. The results indicated that the experimental group (E) exhibited higher plasma glucose, FSH, LEPT, E 2 , and IGF1 levels ( P < 0.05), along with greater numbers of total follicles (TFN), follicles larger than 9 mm (> 9 mm FN), corpora lutea (TCLN), and transferable embryo (TEN) ( P < 0.05). Also, the control group (C) exhibited elevated plasma NEFA concentration ( P < 0.05), with no significant difference in BHB concentration ( P > 0.05). In conclusion, IV glucose administration was associated with increased plasma glucose, IGF1, Leptin, FSH, and E 2 concentrations, as well as improved transferable embryo production.