Estrous cycle of heifers and lactating dairy cows: Ovarian and hormonal dynamics and estrous cycle abnormalities

2017 ◽  
pp. 489-502
Author(s):  
R. Sartori ◽  
J. R. Pursley ◽  
M. C. Wiltbank
Keyword(s):  
Dairy Cows ◽  
Estrous Cycle ◽  
Lactating Dairy Cows

scholarly journals Reduced progesterone concentration during growth of the first follicular wave affects embryo quality but has no effect on embryo survival post transfer in lactating dairy cows

Reproduction ◽  
2011 ◽  
Vol 141 (3) ◽  
pp. 333-342 ◽  
Author(s):  
Fernando A Rivera ◽  
Luís G D Mendonça ◽  
Gláucio Lopes ◽  
José E P Santos ◽  
Rolando V Perez ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Estrous Cycle ◽  
Embryo Quality ◽  
Post Partum ◽  
Embryo Survival ◽  
Follicular Wave ◽  
Lactating Dairy Cows ◽  
Prostaglandin F ◽  
Donor Cows

Fertility of lactating dairy cows is associated with reduced progesterone (P4) concentration compared with nonlactating animals. The objective of the current study was to determine whether P4 during growth of the first follicular wave (FFW) affects embryo quality. Lactating Holstein cows at 33±3 days post partum were allocated to one of three treatments. Cows in the FFW and FFW with P4 (FFWP) treatments started the superstimulation protocol on day 1 of the estrous cycle and second follicular wave (SFW) cows started the superstimulation protocol on estrous cycle day 7. Cows were superstimulated with 400 mg of NIH-FSH-P1 (FSH) given twice daily for 5 days, two prostaglandin F2α (PGF2α) injections given with the ninth and tenth injections of FSH, GNRH given 48 h after the first PGF2α injection, and timed insemination 12 and 24 h after the GNRH injection. Cows in the FFWP treatment received two intravaginal P4 inserts during the superstimulation. Embryos were recovered 6.5 days after artificial insemination and excellent/good and fair embryos were frozen and transferred. Blood was sampled daily from estrous cycle day 0 until insemination from donor cows. During the superstimulation protocol, P4 was (P<0.01) greatest for SFW cows followed by FFWP and FFW cows respectively. The percentage of embryos–oocytes from SFW and FFWP cows classified as excellent/good and fair embryos was (P=0.02) greater than those of FFW cows. Pregnancy per embryo transfer was not (P≥0.73) affected by embryo donor treatment. Reduced embryo quality of cows induced to ovulate the follicles from the first follicular wave is a consequence of reduced P4 during follicle growth.

Follicular dynamics, corpus luteum growth and regression in lactating dairy cattle

1991 ◽  
Vol 71 (1) ◽  
pp. 61-68 ◽  
Author(s):  
C. Taylor ◽  
R. Rajamahendran
Keyword(s):  
Dairy Cows ◽  
Corpus Luteum ◽  
Estrous Cycle ◽  
Follicular Growth ◽  
Dominant Follicle ◽  
Lactating Dairy Cows ◽  
Ovulatory Follicle ◽  
Second Wave ◽  
Lactating Dairy Cattle ◽  
Follicular Dynamics

Ultrasound imaging and progesterone (P4) profiles were used to characterize follicular and corpus luteum (CL) growth and regression in 10 cycling dairy cows. Thirteen of sixteen cycles were characterized by two waves of follicular growth, the second wave giving rise to the ovulatory follicle. The remaining three cycles had three waves. There was no difference between two- and three-wave cycles with regard to the day of emergence of the first or second dominant follicle (day 2.5 ± 0.9 vs. day 2.4 ± 1.2 and day 12.4 ± 1.6 vs. day 12.0 ± 2.0, respectively) or the onset of regression of the first dominant follicle (day 12.5 ± 1.5 vs. day 12.3 ± 1.5). In two wave cycles, estrous cycle length was shorter (20.8 ± 1.7 d vs. 29.7 ± 4.9 d), the first day of decline in P4 (day 16.2 ± 1.5 vs. day 23.7 ± 5.5) and the onset of CL regression (day 17.1 ± 1.3 vs. day 24.3 ± 5.5) was earlier. It is concluded that two waves of follicular growth in an estrous cycle is the norm in lactating dairy cows. The presence of an additional wave is due to a prolonged luteal phase. Key words: Follicle, corpus luteum, estrous cycle, dairy cow

0620 Performance and rumimal metabolism are not changed in lactating dairy cows offered spring available annual forage crops during a short-term grazing experiment

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 294-295
Author(s):  
K. A. Juntwait ◽  
A. F. Brito ◽  
K. S. O'Connor ◽  
R. G. Smith ◽  
K. M. Aragona ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Short Term ◽  
Forage Crops ◽  
Grazing Experiment ◽  
Lactating Dairy Cows

Wood Molasses as a Feed Ingredient for Lactating Dairy Cows

1954 ◽  
Vol 13 (1) ◽  
pp. 44-48
Author(s):  
R. K. Waugh ◽  
J. L. Moore ◽  
H. L. Lucas ◽  
E. W. Faires
Keyword(s):  
Dairy Cows ◽  
Feed Ingredient ◽  
Lactating Dairy Cows
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