Lack of complete regression of the Day 5 corpus luteum after one or two doses of PGF2α in nonlactating Holstein cows (original) (raw)
Related papers
Kansas Agricultural Experiment Station Research Reports, 2017
Lactating Holstein cows in one herd were milked three times daily and enrolled in a 2 × 2 × 2 factorial design with eight treatments before first postpartum artificial insemination (AI). These treatments were employed to test ovulatory, progesterone, and luteolytic outcomes to three main effects: (1) two GnRH-PGF 2α presynchronization programs (PG-3-G vs. Double Ovsynch); (2) 5-vs. 7-day Ovsynch-duration programs; and (3) two doses (25 mg on consecutive days) or one dose (50 mg) of PGF 2α administered before timed AI. Results from this experiment demonstrate no differences in the presynchronization treatments of PG-3-G vs. Double Ovsynch; both are effective in initiating estrous cycles during warm-hot vs. cool-cold seasons. Although ovulatory responses were similar after the first GnRH administration, Double Ovsynch cows tended to have greater ovulation responses after the second GnRH administration. The single large, one-time administered 50-mg dose was effective in causing luteolysis in the 7-day program but slightly less effective in the 5-day program. Thus, when using the shorter 5-day program, the two 25-mg PGF 2α doses administered 24 hours apart are recommended. Insufficient numbers of cows were treated to make conclusions about pregnancy outcomes in this one-herd study. Pregnancy rates, however, were reduced in 5-day Ovsynch program when the single large 50-mg dose of PGF 2α was employed.
2015
M230 Efficacy of PGF2α doses to induce luteolysis on day 5, 7, or 9 of estrus cycle in nonlactating Nellore cows. Marcos V. Biehl*1, Alexandre V. Pires1,2, Marcos V. C. Ferraz Junior2, Jose R. S. Gonçalves3, Anibal B. Nascimento1, Marcelo H. Santos2, Vinicius N. Gouvea2, Alexandre A. Miszura2, Leandro H. Cruppe4, and Michael L. Day4, 1University of São Paulo, Piracicaba, São Paulo, Brazil, 2University of São Paulo, Pirassununga, São Paulo, Brazil, 3Experimental Station Hildegard Georgina Von Pritzelwitz, Londrina, Paraná, Brazil, 4The Ohio State University, Columbus, OH.
Fertility of lactating dairy cows treated with Ovsynch after presynchronization with PGF2a
Veterinary Practitioner, 2010
Objectives of this experiment were to evaluate pregnancy per AI (P/AI) and progesterone (P4) concentrations after AI of lactating dairy cows under heat stress conditions treated with 100 µg gonadotropin-releasing hormone (GnRH) at AI, 5 d after AI, or both. Lactating Holstein cows from two herds were enrolled in the study during summer. Cows detected in estrus based on tail paint removal were allocated to four treatments: (1) control (CON = 722); (2) GnRH treatment at AI (G0 = 739); (3) GnRH treatment 5 d post-AI (G5 = 697); or (4) GnRH treatment at AI and 5 d post-AI (G0+G5 = 697). Blood samples were collected from a subgroup of cows at AI (study d 0), study d 5 and 12 to determine P4 concentrations. Pregnancy diagnosis was conducted at study d 36 and 94. Temperature and relative humidity were collected from a meteorological station nearest the herds and temperature-humidity index (THI) was calculated. Average THI during study enrollment was 83.8 ± 0.1 and THI at study d 0 tended (P = 0.09) to be associated with P/AI at study d 36, but it was not (P = 0.33) associated with P/AI at study d 94. Treatment with GnRH at AI, 5 d after AI, or both, did not affect (P > 0.64) P/AI at study d 36 or 94. An interaction, however, was detected (P = 0.06) between treatment and lactation number. Such an interaction was observed because, among > third-lactation cows, P/AI was greater for G0+G5 (28.6%) and G5 (25.3%) than CON cows (17.3%) at study d 36. Pregnancy per AI of > thirdlactation G0 cows did not (P > 0.11) differ from CON, G5, and G0+G5 cows. No differences in P/AI were detected among treatments in first-and second-lactation cows. Overall, treatments with GnRH at AI, 5 d after AI, or both were not (P = 0.94) associated with P4 concentrations on study d 0, 5 or 12. Among cows diagnosed pregnant at study d 36, progesterone concentration on d 5 was not affected (P > 0.24) by treatments with GnRH at AI, 5 d after AI, or both, but progesterone concentration on d 12 was greater for cows treated with GnRH at AI and 5 d after
The effect of PGF2 on persistent corpus luteum in Sahiwal cows
International Journal of Livestock Production, 2012
In dairy animals, there are so many different conditions, which affect reproductive performance, and persistent corpus luteum (PCL) is one of those. It was suggested that this condition was difficult to treat and consequently result in lengthening of service period and calving interval. If this condition was not diagnosed and treated timely, it may result into permanent infertility and thereby huge loss to the breeders. The commercial availability of PGF2α and its analogues had promoted management and treatment of PCL in other part of the world on different breeds of cows with variable rates of success. This study was designed to determine the response of treatment of Sahiwal cows identified as having PCL with PGF2α (Dalmazin: Fatro Pharmaceutical). The present investigation has been conducted on Sahiwal cows maintained at Livestock Experimental Station, Bahadurnagar, Okara (Pakistan). The cows after 70 to 90 days post-partum were examined per rectum to check the condition of genitalia for PCL and this was also confirmed by progesterone assay in weekly blood samples for three weeks. All cows (n=20: mean weight, 402.0 ± 6.1 kg) sufferings from PCL were treated with 2 ml of Dalmazin intramuscularly on the same day. It was found that 85% of animals as determined by the examination of reproductive tracts and confirmed by progesterone analysis became normal and consequently 60% were pregnant at first service whereas 25% were repeat breeder. In conclusion, the treatment of Sahiwal cows, which were suffering from PCL, with PGF2α may correct this condition successfully.
Theriogenology, 2005
Two experiments evaluated a modified delivery of prostaglandin F 2a (PGF 2a ) after a melengestrol acetate (MGA) treatment in Angus and Bos indicus  Bos taurus (BI) heifers. Experiment 1 was replicated three times with yearling BI heifers (n = 695). Heifers received MGA (0.5 mg head À1 day À1 ) for 14 days. In Replications 1 and 2, heifers received either 25 mg of PGF 2a im 19 days after MGA (single) or 12.5 mg of PGF 2a im 19 and 20 days after MGA (split). In Replication 3, heifers received the same treatments, with PGF 2a initiated either 18 or 19 days after MGA. Estrus was detected for 72 h after PGF 2a , with AI commencing 8-12 h after a detected estrus. Heifers not observed in estrus by 72 h were timed-AI concomitant with GnRH (100 mg im). Heifers from Replication 2 (n = 146) had blood samples collected at the initial PGF 2a and at timed-AI to determine corpus luteum (CL) regression by evaluating plasma progesterone concentrations. The interval from MGA withdrawal to PGF 2a did not have a significant effect on any variable in Replication 3 and there were no treatment by replication effects for any variables, therefore data were pooled. Modifying the PGF 2a treatment from a single treatment to two treatments on consecutive days increased (P < 0.05) 72 h estrous response (43.2% versus 50.1%), timed-AI (23.9% versus 33.5%) and total-AI pregnancy rates (34.5% versus 42.5%), and CL regression (79.1% versus 92.5%), respectively. In Experiment 2, yearling Angus (n = 66) and 2-year-old BI (n = 68) heifers were synchronized as per Experiment 1 (with the initial PGF 2a 19 days after MGA). Neither breed nor PGF 2a treatment effected (P > 0.05) 72 h estrous response, total-AI pregnancy rate, or CL regression rate. In conclusion, treating yearling BI heifers with split treatments of PGF 2a (given on two consecutive days) improved estrous response and pregnancy rates by increasing PGF 2a -induced luteolysis.
The effect of PGF2α on persistent corpus luteum in Sahiwal cows
2015
In dairy animals, there are so many different conditions, which affect reproductive performance, and persistent corpus luteum (PCL) is one of those. It was suggested that this condition was difficult to treat and consequently result in lengthening of service period and calving interval. If this condition was not diagnosed and treated timely, it may result into permanent infertility and thereby huge loss to the breeders. The commercial availability of PGF2α and its analogues had promoted management and treatment of PCL in other part of the world on different breeds of cows with variable rates of success. This study was designed to determine the response of treatment of Sahiwal cows identified as having PCL with PGF2α (Dalmazin: Fatro Pharmaceutical). The present investigation has been conducted on Sahiwal cows maintained at Livestock Experimental Station, Bahadurnagar, Okara (Pakistan). The cows after 70 to 90 days post-partum were examined per rectum to check the condition of genita...
Failure of exogenous LH to prevent PGF2α-induced luteolysis in beef cows
Prostaglandins, 1977
proposed that LH from the preovulatory LH surge attached to receptors on luteal cells and that this attachment might protect the early corpus luteum from PGF2o induced luteolysis. To test this hypothesis, experiments were performed on heifers at day lo-12 of the cycle. Both jugular veins were catheterized and infusions of either saline (0.64 ml/min) or LH-NIH-B9 (10 Ug/min; 0.64 ml/min) were given. Saline infusions were from O-12 h; LH infusions were for 10 h and were preceded by a 2 h saline infusion. All animals were given 25 mg PGF2o im at 6 h (6 h into the saline infusion and 4 h into the LH infusion). Blood samples were taken at 0.5 h, 1 h and 4 h intervals from O-12h, 13-18 h and 22-42 h respectively. Serum was assayed for LH and progesterone by radioimmunoassay methods. Two animals received saline and two received LH in each experiment. Each treatment was replicated 6 times. LH infusion resulted in a mean serum LH of 75 ng/ml compared to 0.90 ng/ml in saline infused animals. This elevation of LH did not alter PGF2, induced luteolysis as indicated by decline in serum progesterone. This experiment does not support the hypothesis that the newly formed corpus luteum is resistant to PGF2, because of protection afforded by the proestrus LH surge.
Researches Regarding the Effect of PGF 2 Α Administration Interval on Cows Estrous Synchronization
To improve reproductive efficiency of a dairy farm hormonal treatments for estrus synchronization are used. These allow heat and A.I. grouping to a specific time interval. In our experiments, we studied the estrous and A.I. grouping after the utilization of three hormonal synchronization programs. The protocols consisted of a single administration of PgF2α, to females with known estrous cycle and AI at 5 days interval, the other two protocols, applied to females with unknown estrous cycle, consisted of two doses of PgF2α, administered at 11 or 14 days interval respectively, and heat detection after the second dose administration. There were no significant differences (p>0.05), between the heat manifestation rates, to cows which were stimulated with two doses of PgF2α, at 11 days interval (85.7%), comparing to cows stimulated with two doses of PgF2α at 14 days interval (88.2%). Significant differences (p<0.05) were observed between the heat manifestation rates of cows to which ...
Journal of Reproduction and Development, 2001
It is well known that an injection of prostaglandin F2α (PGF2α) or its analogue during the mid luteal phase of the estrous cycle induces a rapid decrease in plasma progesterone (P4) concentration, followed by luteolysis in the cow. There is evidence that a potent vasoactive peptide, endothelin-1 (ET-1), is produced in the bovine corpus luteum (CL), and that it is directly involved in luteolysis. We previously found that ET-1 concentrations in the peripheral plasma increase during the period of luteolysis and ovulation in cows. However, it is not clear whether the elevation of peripheral plasma ET-1 concentration observed during luteolysis and ovulation originates exclusively from the ovary and/or CL. Such a profile of plasma ET-1 concentration may be affected by the age of female calves as well as the activity of the ovary. Thus, we aimed to 1) determine in detail the changes in plasma ET-1 and P4 concentrations during the estrous cycle in the cow, 2) investigate plasma changes in ET-1 and P4 concentrations in newborn , 120-day-old and 240-day-old female calves, and 3) examine the effect of luteolytic injection of PGF2α analogue on the plasma ET-1 concentrations in the animals in this study. The peripheral plasma ET-1 concentrations in the cycling cows showed a pulsatile increase. They reached the their highest level (13.66 pg/ml) around the time of luteolysis and estrus, dropped significantly during Days 2-12 (early to mid luteal phase) and Days 13-19 (late luteal phase) (p<0.05), and then increased again on Days 20-22 (p<0.05) when the next estrus appeared. In the peripheral plasma of newborn, 120-day-old and 240-day-old female calves, P4 concentrations remained at low levels (0.1-0.2 ng/ml). ET-1 concentrations in these animals were lower than those in the cycling cows, and remained at low levels throughout the experimental period. Moreover, plasma ET-1 concentrations, unlike those in the cycling cow, did not change after a luteolytic PGF2α injection. In conclusion, the results of the present study gave the first detailed information that plasma ET-1 concentrations increase in a pulsatile manner after the onsets of spontaneous luteolysis and PGF2αinduced luteolysis in cycling cows, but not in female calves. The results suggest that the changes in the plasma ET-1 concentrations during the estrous cycle directly correlate with the cyclic changes in the ovarian function and the uterus.
Comparison of two alternate PGF2α products in two estrus synchronization protocols in beef heifers
Journal of Animal Science
Two experiments were conducted to evaluate the effects of a high concentrate, subcutaneous (s.c.) PGF2α (Prostaglandin F2α) compared with a conventionally concentrated, intramuscular (i.m.) PGF2α in estrus synchronization protocols for heifers. No differences were detected in estrus response or pregnancy rates to artificial insemination (PR/AI) between treatments. Summary In experiment, 1, 869 Angus-based beef heifers were enrolled at 8 locations. All heifers were exposed to the 7-d CO-Synch + controlled internal drug release (CIDR) estrus synchronization protocol. On d-7 of the protocol heifers received 100 µg of gonadotropin-releasing hormone (GnRH) i.m., and a CIDR insert for 7 d. On d 0, at CIDR removal, estrus detection patches were applied to heifers and, within location, heifers randomly received 1 of 2 PGF2α treatments: 5 mL of Lutalyse i.m. (CONTROL; n = 434) or a 2 mL of Lutalyse HighCon s.c. (HiCON; n = 435). A second GnRH injection was administered at 54 ± 2 h and heifers were fixed-time AI (TAI). Heifers were evaluated for estrus activity prior to TAI. Pregnancy rates to AI were diagnosed by transrectal ultrasonography between 35 and 55 d after TAI. The percentage of heifers exhibiting estrus between d 0 and TAI did not differ (P = 0.68) between CONTROL and HiCON treatments (47 vs. 46 ± 4%, respectively). Additionally, PR/AI were similar (P = 0.65) between CONTROL and HiCON treatments (46 vs. 45 ± 3%). In experiment 2, 190 Angus-based beef heifers were enrolled at 2 locations. Heifers were exposed to the melengestrol acetate (MGA)-PGF2α protocol where they were offered 0.5 mg MGA/d from d 1 to 14. On d 33, heifers were randomly assigned to receive CONTROL (n = 95) or HiCON (n = 95) treatment, and estrus detection aids were applied. Heifers were exposed to AI 12 h after being detected in estrus. Heifers not detected in estrus at location 1 from d 33 to 39 received a second PGF2α injection 6 d after the initial PGF2α injection, and were exposed to natural service. Heifers at location 2 which did not express estrus from d 33 to 36 were administered 100 µg of GnRH i.m. and exposed to TAI 96 h post PGF2α injection. Transrectal ultrasonography was used to diagnose PR/AI between 51 and 57 d after the initial PGF2α injection. The percentage of heifers exhibiting estrus during the estrus detection period was similar (P = 0.40) between CONTROL and HiCON treatments (82 vs. 87 ± 4%). Furthermore, PR/AI were similar (P = 0.62) between CONTROL and HiCON treatments (60 vs. 65 ± 5%). We conclude that the 2 concentrations and corresponding routes of administration of PGF2α were similar in efficacy at synchronizing estrus in beef heifers.