Variation in the timing of ovulation relative to other follicular phase events following natural and induced luteal regression in dairy cows

1999 ◽  
Vol 1999 ◽  
pp. 63-63 ◽  
Author(s):  
G.E. Mann ◽  
G.S. Starbuck ◽  
M. Benboulaid ◽  
A.R. Peters ◽  
G.E. Lamming
Keyword(s):  
Dairy Cows ◽  
Follicular Phase ◽  
Ultrasound Scanning ◽  
Luteal Regression ◽  
Factors Associated ◽  
Precise Timing ◽  
Breeding Programmes ◽  
Prostaglandin F

Insemination at an inappropriate time is one of many constraints to good fertility in dairy cows. As a result, many studies have attempted to improve the synchrony of oestrus in controlled breeding programmes. However, the success of insemination depends not merely on the detection of oestrus, but also on the timing of ovulation relative to insemination. Thus a better understanding of the factors associated with the precise timing of behavioural oestrus and ovulation is required. In this study the time of ovulation has been determined, by ultrasound scanning, in relation to a variety of follicular phase events in dairy cows following both natural luteolysis and luteolysis induced by treatment with a prostaglandin F2a analogue. The objectives were firstly to determine whether differences existed in the timing of follicular phase events following natural and induced luteal regression and secondly to determine the degree of variation that exists between the timing of ovulation and the timing of other follicular phase events.

Inhibin secretion by the sheep ovary during the luteal and follicular phases of the oestrous cycle and following stimulation with FSH

1988 ◽  
Vol 117 (2) ◽  
pp. 283-291 ◽  
Author(s):  
C. G. Tsonis ◽  
A. S. McNeilly ◽  
D. T. Baird
Keyword(s):  
Luteal Phase ◽  
Venous Blood ◽  
Follicular Development ◽  
Follicular Phase ◽  
Pituitary Cells ◽  
Luteal Regression ◽  
Follicular Maturation ◽  
Prostaglandin F ◽  
Late Follicular Phase ◽  
Multiple Follicular Development

ABSTRACT The secretion of oestradiol and inhibin were measured during the follicular and luteal phase of the cycle by a sensitive bioassay using sheep pituitary cells in culture in four ewes in which the left ovary had been autotransplanted to the neck. On day 12 of the cycle, premature luteal regression was induced with an injection of 100 μg cloprostenol (prostaglandin F2α analogue; PG) and ovarian venous blood was collected every 4 h for 72 h. These same four ewes were infused in the ensuing cycle with NIH-oFSH-S14 at 10 μg/h for 48 h immediately after an injection of PG and sampled as above. During the luteal phase ( − 2 h before PG) both in the control and FSH-infused cycles the inhibin secretion rate (SR) was 27–45 units/min. After PG injection, the inhibin SR declined with time to reach 3·6–5 units/min at the onset of the LH surge (60 h after PG) in the control cycle. In contrast, in the following cycle infusion of FSH after PG injection caused a slight increase in the inhibin SR which then remained raised at 42–50 units/min for up to 60 h after PG. In the late follicular phase the oestradiol SR was greater in the FSH-infused than in the control cycles, indicating multiple follicular development. In the FSH-infused cycle the preovulatory surges of LH and FSH were markedly attenuated. These data demonstrate that (1) inhibin SR is high during the luteal phase suggesting that the sheep corpus luteum secretes inhibin, (2) in the control cycle inhibin SR declines during follicular maturation at a time when oestradiol SR is increasing but FSH levels are decreasing, and (3) exogenously administered FSH stimulates the secretion of inhibin from the ovary during the follicular phase. J. Endocr. (1988) 117, 283–291

scholarly journals Prevalence of and factors associated with hock, knee, and neck injuries on dairy cows in freestall housing in Canada

2014 ◽  
Vol 97 (1) ◽  
pp. 173-184 ◽  
Author(s):  
J.C. Zaffino Heyerhoff ◽  
S.J. LeBlanc ◽  
T.J. DeVries ◽  
C.G.R. Nash ◽  
J. Gibbons ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Neck Injuries ◽  
Factors Associated

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.

Methods for assessing sociability of dairy cows

2007 ◽  
Vol 2007 ◽  
pp. 38-38
Author(s):  
J. Gibbons ◽  
A. B. Lawrence ◽  
M. Haskell
Keyword(s):  
Individual Differences ◽  
Dairy Cattle ◽  
Dairy Cows ◽  
Social Behaviour ◽  
Social Motivation ◽  
Welfare Assessment ◽  
Suitable Test ◽  
Breeding Programmes ◽  
Social Companionship ◽  
Reliable Methods

Sociability refers to the extent to which animals seek social companionship. Individual differences in social behaviour exist between animals. It is important to measure individual social motivation in order to develop suitable temperament scores that can be used in future breeding programmes or as part of welfare assessment schemes. Runway tests have been shown as reliable methods of measuring sociability in animals (Birds Mills & Faure, 1991; Sheep Sibbald et al., 2005). The aim was to develop a suitable test that could be used to measure sociability of cows in a commercial situation. The following questions were addressed i) How repeatable is the runway test when carried out on dairy cattle, ii) Does a cow’s performance in a runway test correlate with social behaviour within a group house setting?

Improving reproductive performance in lactating dairy cows by synchronising ovulation or inducing oestrus

2002 ◽  
Vol 50 (2) ◽  
pp. 231-234 ◽  
Author(s):  
Gy. Gábor ◽  
J. P. Kastelic ◽  
S. Pintér ◽  
Keyword(s):  
Dairy Cows ◽  
Reproductive Performance ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Preliminary Trial ◽  
Lactating Cows ◽  
Lactating Dairy Cows ◽  
Considerable Promise ◽  
Holstein Friesian ◽  
Prostaglandin F

Lactating crossbred Holstein-Friesian dairy cows (n = 331) were started on an Ovsynch regimen 68 ± 8.2 days after calving; 200 µg GnRH intramuscularly (i.m.) on Days 0 and 9, and 35 mg prostaglandin F2a i.m. on Day 7. Thirty-eight and 31 cows (11.5 and 9.4%, respectively) were in oestrus on Days 0 to 6 and 7 to 8, respectively, and inseminated, and the remainder were fixed-time inseminated (on Day 10). For these three groups, pregnancy rates (60-65 days after breeding) were 31.6, 38.7 and 34.0%, respectively (P = 0.82) and calving rates were 100, 100 and 89.9% (P = 0.23). In a preliminary trial, twelve lactating cows (45 to 60 days postpartum) with inactive ovaries were given 1500 IU eCG i.m.; 10 were in oestrus within 10 days after treatment (and inseminated) and eight of these were pregnant (30 days after breeding). The Ovsynch program resulted in acceptable reproductive performance in cyclic cows and eCG treatment has considerable promise for inducing oestrus in anoestrous cows.

scholarly journals Factors Associated with Milk Urea Concentrations in Ontario Dairy Cows

2001 ◽  
Vol 84 (1) ◽  
pp. 107-114 ◽  
Author(s):  
S.M. Godden ◽  
K.D. Lissemore ◽  
D.F. Kelton ◽  
K.E. Leslie ◽  
J.S. Walton ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Factors Associated ◽  
Milk Urea

scholarly journals Effects of GnRH, PGF2α and oxytocin treatments on conception rate at the time of artificial insemination in lactating dairy cows

2011 ◽  
Vol 56 (No. 6) ◽  
pp. 279-283 ◽  
Author(s):  
A. Gümen ◽  
A. Keskin ◽  
G. Yilmazbas-Mecitoglu ◽  
E. Karakaya ◽  
S. Cevik ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Artificial Insemination ◽  
Reproductive Tract ◽  
Female Reproductive Tract ◽  
Conception Rate ◽  
Beneficial Effects ◽  
Lactating Dairy Cows ◽  
Conception Rates ◽  
Prostaglandin F ◽  
And Control

In several studies, hormones such as gonadotropin-releasing hormone (GnRH), prostaglandins and oxytocin were used to increase pregnancy rate by inducing ovulation and improving the sperm transport in the female reproductive tract in lactating dairy cattle. The objective of this study was to compare the effects of GnRH, prostaglandin F<sub>2&alpha;</sub> (PGF<sub>2&alpha;</sub>) and oxytocin treatments at the time of artificial insemination (AI) after spontaneous oestrus on the conception rate (CR) of lactating dairy cows. Oestrus was detected by visual observations by experienced personnel. All cows (n = 430, 308 Holstein-Frisian and 122 Swedish-Red dairy cows) were inseminated based on the am/pm rule by veterinarians of the farm. After AI, cows were alternately assigned to one of the four treatment groups: (1) GnRH (n = 113); (2) PGF<sub>2&alpha;</sub> (n = 106);<br />(3) oxytocin (n = 106) and (4) non-treated control (n = 105). Pregnancy diagnosis was performed 28&ndash;34 and 58&ndash;64 days post-insemination by transrectal ultrasonography. Conception rates on days 28&ndash;34 and 58&ndash;64 were not different among GnRH (46.0%; 52/113 and 44.3%; 50/113), PGF<sub>2&alpha;</sub> (37.7%; 40/106 and 35.9%; 38/106) and control (49.5%; 52/105 and 47.6%; 50/105) groups. However, conception rates were lower (P = 0.02) in oxytocin (31.1%; 33/106 and 30.2%; 32/106) than in GnRH and control groups on days 28&ndash;34 and 58&ndash;64. Other covariant factors, such as milk production, days in milk (DIM), breed, parity, service number did not affect the conception rate. Thus, there were no beneficial effects of treatments with GnRH and PGF2&alpha; at the time of AI, and oxytocin had an adverse effect on CR in lactating dairy cows in this study.

scholarly journals Effect of two low doses of prostaglandin F2α on luteolysis in dairy cows

2017 ◽  
Vol 65 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Tsung-Ching Liu ◽  
Chia-Yu Ho ◽  
Jacky Peng-Wen Chan
Keyword(s):  
Dairy Cows ◽  
Standard Dose ◽  
Prostaglandin F2α ◽  
Low Doses ◽  
Serum Progesterone ◽  
Modified Method ◽  
Dose Method ◽  
Prostaglandin F ◽  
Preliminary Study ◽  
Larger Sample

In this preliminary study, we determined the effect of a modified method involving the administration of two low doses of prostaglandin F2α (PGF2α) at an interval of 24 h on luteolysis in dairy cows, and compared it with the standard single-dose method. Twenty-six cows were assigned to three groups treated with two low doses (TLD group, n = 10), one standard dose (SD group, n = 10), and one low dose (OLD group, n = 6) on day 9 to 10 of the oestrous cycle (day 0 = the day of PGF2α administration). Their serum progesterone (P4) levels and corpus luteum (CL) sizes were measured daily from day 0 to 4 to assess CL regression. The results indicated that the proportion of complete luteolysis, indicating a P4 value ≤ 1 ng/mL on day 3, was higher in the TLD group (100.0%) than in the SD (60.0%) and OLD (66.7%) groups. Ultrasonically detected changes in the CL area correlated with the shifts in the P4 values in both the TLD and the SD groups. The remaining CL area was significantly smaller in the TLD group (17.8% ± 3.3%) than in the SD or OLD group on day 4. Thus, we concluded that the proportion of luteolysis in cows was increased with two low doses of PGF2α as compared to a single PGF2α dose, indicating the necessity of the second dose of PGF2α. However, further studies with larger sample sizes in the field are required.

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