Chemical composition and antibacterial activity of essential oils against pathogens often related to cattle endometritis.

INTRODUCTION: Endometritis is a condition marked by inflammation of the endometrium that affects dairy cows from 21 days after parturition, causing damage to herd fertility and economic losses on farms. The use of active compounds obtained from plant sources has gained importance as disease treatment agents in farm animals due to the high resistance rates currently observed against traditional antibiotics commonly used. The study was carried out to examine the chemical composition and to investigate the antibacterial activity of rosemary, cinnamon, cloves, eucalyptus, lemon, oregano and thyme essential oils against the reference strain of Escherichia coli (ATCC 25922), Fusobacterium necrophorum (ATCC 25286), Trueperella pyogenes (ATCC 19411) and Staphylococcus aureus (ATCC 29213), considered as typical bacteria causing endometritis. METHODOLOGY: The chemical composition of the seven essential oils were analyzed by GC-MS and their antibacterial activity was evaluated by the disc diffusion method. RESULTS: Thirty-six components were identified in total using GC-MS analyzes. The main compounds were cinnamaldehyde (86.5% for cinnamon essential oil), eugenol (85.7% for clove essential oil), 1,8-cineol (80% for eucalyptus and 47.8% rosemary essential oils), limonene (65.5% for lemon essential oil), carvacrol (72.1% for oregano essential oil) and thymol (48.8% for thyme essential oil). The disc diffusion assay revealed that cinnamon, clove, oregano, and thyme essential oils showed the best results compared to the other three essential oils, showing the largest zone of inhibition against all bacteria evaluated. CONCLUSIONS: These findings indicated that essential oils are a potential agent to be used as an alternative for bovine endometritis treatment.

Uterine Involution and Reproductive Performance in Dairy Cows with Metabolic Diseases.

The aim of this study was to investigate the effects of metabolic diseases on uterine involution and reproductive performance during the postpartum period. Multiparous Holstein dairy cows (n = 50) were divided into four groups based on whether they were healthy (n = 14), or had lipomobilization (n = 14), hypocalcemia (n = 11), and hyperketonemia (n = 11). Transrectal palpation and transrectal B-Mode sonography were carried out on days 7, 14, 21, 30, 45 and 60 after parturition. Cows with metabolic disease had a greater (p < 0.05) uterine size as assessed transrectally compared with cows without metabolic disease. Sonographic measurements revealed a greater (p < 0.05) horn diameter and endometrial thickness in cows of the metabolic disease groups than in the healthy cows. Metabolic disease affected (p < 0.05) the milk yield, percentage of service per pregnancy, days to first ovulation and days open. In conclusion, metabolic disease affected the uterine involution and fertility during the postpartum period.