The study aimed to compare differences of physiological acid-base balance (ABB) parameters in follicular fluid (FF) and venous blood (VB) and to evaluate ABB parameters in FF collected from different ovarian follicles in dairy cows and heifers. The ABB parameters (pH, pCO2, pO2, HCO3– and base excess (BE)) in the FF of the preovulatory follicle, of the dominant follicle on the 9th day of the cycle and of the superovulatory estrous follicles were compared to VB. Similarly, the dynamics of the ABB profile in FF and VB were monitored in repeated sampling in a group of heifers stimulated by follicle-stimulating hormone (FSH). Higher values of pH and pO2 and lower values of pCO2, HCO3– and BE were found in FF compared to VB in all experiments. Laterality of ovaries, time of sampling, ovarian activity or stimulation of the follicular development by FSH did not significantly influence ABB parameters. We found higher pH (7.392 ± 0.027 vs. 7.364 ± 0.032) and pO2 (13.83 ± 2.20 kPa vs. 4.50 ± 0.67 kPa), lower pCO2 (5.70 ± 0.39 kPa vs. 6.54 ± 0.61 kPa), HCO3– (25.51 ± 1.52 mmol/l vs. 26.86 ± 2.12 mmol/l) and BE (1.14 ± 1.57 mmol/l vs. 1.95 ± 2.2 mmol/l) in FF compared to VB in all non-stimulated cows. Similar relationships between FF and VB were found in all FSH stimulated cows. The study provides as yet unknown knowledge on the physiology of follicular fluid in cattle.
Vlcek M., Andrlikova M., Barbato O., Bina V., Boland M.P., Dolezel R., Lopatarova M., Cech S. (2017): Supplementation of dairy cows with docosahexaenoic acid did not affect ovarian activity. Czech J. Anim. Sci., 62, 457-465.The effect of docosahexaenoic acid (DHA) on ovarian activity of dairy cows was determined. Experimental cows (n = 25) were fed a total mixed ration supplemented daily with 100 g/cow of an algae product All-G-Rich (Alltech, Ireland) containing 10% DHA divided into 2 doses for 52 days. Determination of DHA from milk samples taken from all cows was performed before the All-G-Rich supplementation (on Day 0, D0), and on D21 and D42 of algae supplementation. Cows were synchronized to be in oestrus on D21 and D42 of the experimental period. Monitoring of ovarian activity was performed by transrectal ultrasonography. Examinations were performed at 2-3-day intervals from D0 until D52 of the experimental period. Plasma concentrations of progesterone, oestradiol, insulin, NEFA, and cholesterol were determined. Control cows (n = 25) were examined in the same way as the experimental cows. Milk DHA concentrations on D21 and D42 were significantly higher in treated cows (D21 1.38 vs 0.28, P < 0.0001; D42 1.34 vs 0.20, P < 0.0001). There were neither important effects of DHA on ovarian structures, nor on evaluated variables in plasma. Cows in the experimental group tended to have larger corpora lutea and higher cholesterol concentrations, but differences were not significant.
The aim of the study was to develop and evaluate the functionality of a new equipment for intrafollicular oocyte transfer (IFOT) in dairy cattle. The new system for IFOT is composed of the applicator, the aspirator, and the injector. After aspiration of oocytes, the IFOT set is inserted into the working tube of the ultrasound transducer holder, the content of the applicator can be injected into the preovulatory follicle via transvaginal ultrasonography by one operator. The function of instruments used for IFOT was firstly verified in laboratory conditions. Slaughterhouse oocytes filled into the instruments were injected into Petri dishes. The highest recovery rates in vitro (97.5%) were achieved when the applicator was stored with the needle in a downward position. Synchronized Holstein heifers were used for in vivo test. Intrafollicular injection of saline (n = 9) was performed to find whether ovulation is affected by the injection. Then IFOTs of phosphate buffered saline with 20 oocytes (n = 21) were performed into the preovulatory follicles followed by 7-day-old embryo collection. Total ovulation rates were 86.7% (26/30). Total recovery rates (oocytes + embryos) were 23.1%, embryo recovery rates were 10.1%. The new instrument allows for the loading of oocytes and easy transportation to recipients, and also allows IFOT to be performed by one person in field conditions. The method does, however, need further investigation.
The study aimed to determine the effect of the treatment by pegbovigrastim on the health of the mammary gland in dairy cows. Experimental animals were successively treated with 15 mg of pegylated bovine granulocyte colony-stimulating factor (bG-CSF, pegbovigrastim, PEG, Imrestor, Elanco) 10 ± 3 days before expected parturition and 1 day after actual parturition. Cows in the control group remained without treatment. The occurrence of clinical and subclinical mastitis in dairy cows during the first three months postpartum, and bacteriological findings in milk and milk yield were evaluated after preventive pegbovigrastim treatment. The influence of pegbovigrastim, as an additional treatment of mastitis caused by Streptococcus uberis in dairy cows on the standard course of treatment, was evaluated. The average number of antimicrobial (AML) interventions necessary for healing, the proportion of cows with 1, 2, 3 and more AML interventions, milk somatic cell count before treatment, 1 and 2 months after treatment and average milk withdrawal time were evaluated between groups. The results of the study did not find positive effects of pegbovigrastim on any evaluated variables.
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