共查询到3条相似文献,搜索用时 0 毫秒
1.
Natsumi ENDO Kiyosuke NAGAI Tomomi TANAKA Hideo KAMOMAE 《The Journal of reproduction and development》2013,59(2):107-114
The present study was designed to assess progesterone profiles at the secreted (caudal
vena cava) and circulating levels (jugular vein) and luteinizing hormone (LH) secretion
pattern in lactating and non-lactating cows with reference to feeding. Four lactating and
four non-lactating cycling Holstein cows were examined. Blood samples were collected
simultaneously from the caudal vena cava (via a catheter inserted from the coccygeal vein)
and the jugular vein every 15 min for 12 h (0500–1700 h) during the functional luteal
phase. Cows were fed 50% of the daily diet 6 h after the start of blood sampling. During
the 12-h sampling period, mean progesterone concentrations in the caudal vena cava did not
differ between lactating and non-lactating cows (49.0 ± 2.9 and 53.3 ± 3.7 ng/ml; mean ±
SE), whereas mean progesterone concentrations in the jugular vein in lactating cows were
higher than those in non-lactating cows (6.4 ± 0.1 and 5.6 ± 0.1 ng/ml, P < 0.001).
Lactating cows had a higher frequency of LH pulses than non-lactating cows (7.0 ± 0.7 and
4.3 ± 0.9 pulses/12 h, P<0.05). The influence of feeding was not observed on LH
profiles but was observed on progesterone profiles in both veins. Progesterone
concentrations in the caudal vena cava increased after feeding in both groups.
Progesterone concentrations in the jugular vein decreased after feeding in lactating cows
but not in non-lactating cows. These results indicate the difference in feeding-related
changes in progesterone dynamics between lactating and non-lactating cows. 相似文献
2.
Naoya KAWAHARA Yoshiyuki TSUCHIYA Natsumi ENDO Tomomi TANAKA 《The Journal of reproduction and development》2023,69(1):41
To improve the accuracy of ultrasonographic assessment of luteal function, we investigated the relationship between ovarian ultrasonographic findings on Day 7 (Day 1 = ovulation) and plasma progesterone (P4) concentration, nutritional metabolic factors, and pregnancy outcome. A total of 47 spontaneous estrus events were investigated in 38 lactating Holstein cows (artificial insemination, n = 31; embryo transfer, n = 16). Transrectal ultrasonography was performed on Days 0 and 7 to measure the pre-ovulatory follicle area on Day 0 and the luteal tissue area (LTA), luteal blood flow area (LBF), relative LBF (rLBF) (= LBF/LTA), and dominant follicle area (DFA) on Day 7. Blood samples were collected on Day 7 to measure plasma P4, insulin-like growth factor-I (IGF-I), insulin, and metabolites. Plasma P4 concentration was positively correlated with LTA but was not associated with LBF or rLBF. Plasma P4 concentration was positively correlated with blood glucose and IGF-I and negatively correlated with blood urea nitrogen and free fatty acid, and no significant relationship was found between the ultrasonographic findings of the corpus luteum (CL) and these blood metabolites. Pregnant cows had smaller DFA than non-pregnant cows. In conclusion, LTA measurement can help predict plasma P4 concentration, but it was difficult to detect variations in plasma P4 concentration in relation to changes in energy status by evaluating the CL ultrasonographically. A combined assessment of CL and first-wave dominant follicle may be important in evaluating fertility. 相似文献
3.
Aly KAREN árpád Csaba BAJCSY Rosa MINOIA Rezs? KOVáCS Noelita Melo DE SOUSA Jean-Fran?ois BECKERS János TIBOLD István MáDL Ottó SZENCI 《The Journal of reproduction and development》2014,60(2):162-167
The aim of the present study was to determine the relationship of progesterone (P4),
bovine pregnancy-associated glycoprotein-1 (bPAG-1) and nitric oxide (NO) levels with late
embryonic (LEM; day 28 to day 42) and early fetal mortalities (EFM; > day 42 to day 56)
in dairy cows. Transrectal ultrasonography (6–8 MHz) was performed in 100
Holstein-Friesian cows at days 28, 42 and 56 after artificial insemination (AI; day 0) to
diagnose pregnancy and to monitor the fate of the embryo. After ultrasound scanning of
each cow, a milk sample was collected for assessment of P4 by an ELISA test and a blood
sample was collected for assessment of bPAG-1, by using a double-antibody
radioimmunoassay, and serum NO metabolites (nitrate + nitrite). Based on ultrasonographic
examinations and bPAG-1-RIA, 41 of 100 inseminated cows were confirmed pregnant at day 28
after AI. Nine cows suffered of LEM, and 6 cows suffered of EFM and the overall pregnancy
loss rate was 36.6% (15/41) between days 28 and 56 of pregnancy. By logistic regression
analysis, there were no significant relationships between the level of P4 and bPAG-1 at
day 28 after AI and the occurrence of LEM and EFM. Also, there were no significant
relationships between the levels of P4 and bPAG-1 at day 42 and the occurrence of EFM. On
the other hand, a significant relationship (P<0.05) was found between NO level at day
28 and the occurrence of LEM. In conclusion, measurement of the serum NO concentration at
day 28 of pregnancy might help to predict the outcome of pregnancy by day 42 in dairy cows
but further studies are needed to confirm this. 相似文献