scholarly journals 52 Timing of progesterone exposure effects pregnancy rates following fixed timed artificial insemination in postpartum beef cows

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 85-85
Author(s):  
Anna L Smith ◽  
Rebecca K Poole ◽  
Kyle Mayberry ◽  
McKayla A Newsome ◽  
Harrison B Dudley ◽  
...  
Keyword(s):  
Artificial Insemination ◽  
Statistical Significance ◽  
Beef Cows ◽  
Reproductive Technologies ◽  
Pregnancy Rates ◽  
Estrous Synchronization ◽  
Ultrasonographic Diagnosis ◽  
Pregnancy Status ◽  
Timed Artificial Insemination ◽  
The Impact

Abstract Advancements in reproductive technologies have improved pregnancy rates in postpartum cows; however, undesirable consequences leading to reduced fertility still occur. Thus, the objectives were to determine if presence of a corpus luteum (CL) at the start of estrous synchronization (AIM1) or if the length of proestrus (interval from progesterone removal to a GnRH-induced LH surge; AIM2) alters fixed timed artificial insemination (FTAI) pregnancy rates. Cycling postpartum cows (n = 285) at two locations were synchronized using the CO-Synch+CIDR® FTAI protocol. Ultrasonographic measurements of luteal area were recorded at CIDR insertion. To determine the impact of proestrus length, cows were randomly assigned to either undergo CIDR removal at the time of PGF2a injection (long proestrus, n = 145), or CIDR removal 24 hours post PGF2a injection (short proestrus, n = 140). Blood samples were collected at CIDR insertion and at insemination for progesterone (P4) analysis. Pregnancy status to FTAI was assessed using ultrasonographic diagnosis at 30 d post insemination. Data were analyzed using a MIXED procedure of SAS and examined for effects of length of proestrus, P4 concentration, luteal area, sire, location, and age. Statistical significance was determined at P 0.05) pregnancy rates. Pregnancy rates were greater in cows with >1 ng/mL P4 compared to cows with 0.05). Cows > 4 y old had higher AI pregnancy rates compared to 2–3 y cows (70.2±7.4 vs. 51±5.8%, respectively; P > 0.05). Based on these data, incorporating a presynchronization program to ensure the presence of a functional CL at the start of a FTAI protocol may improve pregnancy success in postpartum beef cows.

scholarly journals 107 Timing of progesterone exposure effects pregnancy rates following fixed time artificial insemination in postpartum beef cows

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 43-44
Author(s):  
Anna L Smith ◽  
Rebecca K Poole ◽  
Kyle Mayberry ◽  
McKayla A Newsome ◽  
Harrison B Dudley ◽  
...  
Keyword(s):  
Artificial Insemination ◽  
Statistical Significance ◽  
Fixed Time ◽  
Beef Cows ◽  
Reproductive Technologies ◽  
Pregnancy Rates ◽  
Estrous Synchronization ◽  
Pregnancy Status ◽  
Timed Artificial Insemination ◽  
The Impact

Abstract Advancements in reproductive technologies have improved pregnancy rates in postpartum cows; however, undesirable consequences leading to reduced fertility still occur. Thus, the objectives were to determine if presence of a corpus luteum (CL) at the start of estrous synchronization (AIM1) or if the length of proestrus (interval from progesterone removal to a GnRH-induced LH surge; AIM2) alters fixed timed artificial insemination (FTAI) pregnancy rates. Cycling postpartum cows (n = 285) at two locations were synchronized using the CO-Synch+CIDR® FTAI protocol. Ultrasonographic measurements of luteal area were recorded at CIDR insertion. To determine the impact of proestrus length, cows were randomly assigned to either undergo CIDR removal at the time of PGF2a injection (long proestrus, n = 145), or CIDR removal 24 hours post PGF2a injection (short proestrus, n = 140). Blood samples were collected at CIDR insertion and at insemination for progesterone (P4) analysis. Pregnancy status to FTAI was assessed using ultrasonographic diagnosis at 30 d post insemination. Data were analyzed using a MIXED procedure of SAS and examined for effects of length of proestrus, P4 concentration, luteal area, sire, location, and age. Statistical significance was determined at P0.05) pregnancy rates. Pregnancy rates were greater in cows with >1 ng/mL P4 compared to cows with 0.05). Cows > 4 y old had higher AI pregnancy rates compared to 2–3 y cows (70.2±7.4 vs. 51±5.8%, respectively; P > 0.05). Based on these data, incorporating a presynchronization program to ensure the presence of a functional CL at the start of a FTAI protocol may improve pregnancy success in postpartum beef cows.

Setting the Cycle for Reproductive Success with a Pre-synchronization Program in Postpartum Beef Cows

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 23-23
Author(s):  
Macy M Massengill ◽  
Thiago V Silva ◽  
Daniel H Poole
Keyword(s):  
Body Condition Score ◽  
Statistical Significance ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Estrous Synchronization ◽  
Condition Score ◽  
Pregnancy Status ◽  
Timed Artificial Insemination ◽  
To Receive ◽  
Synchronization Protocol

Abstract Previous experiments from our laboratory determined that postpartum beef cows with a functional corpus luteum (CL) at the start of an estrous synchronization protocol have greater pregnancy success to FTAI than those that did not have a CL. Therefore, it was hypothesized that incorporation a presynchronization program prior to FTAI in postpartum cows will improve pregnancy rates. The goal of this project was to compare the effectiveness of a presynchronization program prior to the 7-d CO-Synch+CIDR fixed timed artificial insemination (FTAI) protocol in postpartum cows. Postpartum cows (n = 310) at two locations were randomly assigned to receive either the presynchronization program, consisting of 2 PGF2α injections 14 d apart and 11 d prior to the start of the 7-d CO-Synch+CIDR protocol, or the 7-d CO-Synch + CIDR protocol. Following estrus synchronization, all cows were inseminated by trained technicians using semen from bulls of known fertility. Pregnancy status to FTAI was assessed using ultrasonographic diagnosis at 30 d post insemination. Data were analyzed using a MIXED procedure of SAS and examined for effects of inseminator, body condition score (BCS), and location and age. Statistical significance was determined at P < 0.05 and a tendency at 0.05< P < 0.10. Age, BCS, and location did not affect (P > 0.05) pregnancy rates. Cows exposed to the pre-synchronization program tended to have greater AI pregnancy rates compared to cows that did not receive the pre-synchronization program (57.7±5.3 vs. 46.9±5.3%, respectively; P = 0.0687). AI pregnancy rates were greater in cows with >1 ng/mL P4 compared to cows with < 1 ng/mL P4 at the start of FTAI (77.7±7 vs. 55.7±6.2%, respectively; P = 0.0204). Furthermore, AI pregnancy rates were decreased by inseminator C (26.1±7.4) compared to the other inseminators this breeding season (A-54.4±7.9; B- 62.3±5.3; D-57.8±7.2; and E -51.1±5.2; P = 0.0026). Based on these data, incorporating a pre-synchronization program to ensure the presence of a CL at the start of a FTAI protocol may improve pregnancy success in postpartum beef cows.

scholarly journals 128 Pregnancy and calving rates of beef cows comparing the sex-selected semen to conventional semen using timed artificial insemination

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 1-1
Author(s):  
Jennifer McMurray ◽  
Andrea N DeCarlo ◽  
Nathan Long ◽  
Scott Pratt
Keyword(s):  
Artificial Insemination ◽  
Post Partum ◽  
Statistical Significance ◽  
Fixed Time ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Chi Square ◽  
Estrous Synchronization ◽  
Beef Cow ◽  
Sexed Semen

Abstract A study was conducted over three years to determine if differences in pregnancy rates existed between the use of commercially available sex-selected (SEXED) or conventional semen (STD) coupled to fixed-time artificial insemination (TAI). A total of 240 (2016: n = 80; 2017: n = 95; 2018: n = 65) primi- or multiparous Angus or Angus-cross cows being at 45 days post-partum or greater were blocked by weight and BCS and assigned to be inseminated using SEXED semen or STD semen. Artificial insemination was performed by the same AI technicians (n = 3) across all years. All cows were subjected to estrous synchronization and insemination using the SEXED semen or STD semen with TAI between 63 and 66 h post-CIDR removal. Fourteen days post-TAI all cows were exposed to bulls for natural service. Cows were subjected to transrectal ultrasonography at day 30 and day 45 post-TAI to determine pregnancy rates and calving dates in the subsequent calving seasons were recorded to determine calving rates to TAI. Pregnancy rates were compared using a Chi-square test of two proportions. All statistical calculations were performed using JMP software and statistical significance was based on p-values less than 0.05. Pregnancy rates at day 30 and day 45 were 39.67% and 48.76% for SEXED and 47.90% and 54.62% for STD, respectively (P > 0.05). The percentage of calves born to TAI pregnancies for sex-selected semen and conventional semen were 22.31% and 40.34%, respectively (P < 0.05). These data indicate that the use of sex-selected semen can give similar pregnancy results to conventional semen in beef cow operations using TAI at day 30 of gestation; however, there was a reduction in the number of offspring to TAI comparing calving dates to animals pregnant at day 30.

scholarly journals PSII-21 Vaginitis incidence and effects on fertility of beef females enrolled on estrus synchronization protocols using a controlled internal drug release (CIDR) device

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 242-242 ◽  
Author(s):  
Nicholas W Dias ◽  
Alvaro Sales ◽  
Claire Timlin ◽  
Stefania Pancini ◽  
John Currin ◽  
...  
Keyword(s):  
Drug Release ◽  
Pregnancy Rate ◽  
Artificial Insemination ◽  
Pregnancy Rates ◽  
Estrus Synchronization ◽  
Pregnancy Status ◽  
Timed Artificial Insemination ◽  
System 1 ◽  
Synchronization Protocol

Abstract Our objectives were to characterize the incidence of vaginitis caused by a controlled internal drug release (CIDR) device and its effects on fertility of beef females enrolled on estrus synchronization followed by timed-artificial insemination (TAI). A total of 1,097 mature cows and 215 heifers from 9 different locations were enrolled in the 7-d CO-Synch + CIDR synchronization protocol. At CIDR insertion, all females were inspected for any previous signs of vaginitis prior to enrollment in the experiment. As evidence of vaginitis, a CIDR score was determined at CIDR removal, and an AI plastic sheath score was also performed at TAI following a 1 to 4 system: 1=clean presenting no secretion; 2=clean presenting clear secretion; 3=presence of purulent secretion; 4=presence of purulent secretion and blood. Pregnancy status was determined by rectal ultrasonography approximately 40 days after TAI. The scores for CIDR and AI plastic sheath did not differ between cows and heifers. Of all females, 6% had a CIDR score of 1, 31% score 2, 56% score 3, and 7% score 4. Plastic sheath score was 1 for 16%, 2 for 62%, 3 for 15%, and 4 for 7% of females. Pregnancy rate to TAI differed between cows and heifers (P < 0.01), among locations (P < 0.001) and ranged from 36 to 66%; however, it was not influenced by CIDR score (P = 0.259) and plastic sheath score (P = 0.785). Pregnancy rate of females by different CIDR scores was 60%, 57%, 52%, and 46% for scores 1, 2, 3, and 4, respectively. Pregnancy rate of females by different AI plastic sheath score was 60%, 55%, 45%, and 48%, for scores 1, 2, 3, and 4, respectively. The presence of vaginitis caused by a CIDR does not influence pregnancy rates of TAI in beef females.

scholarly journals Artificial insemination system without estrous observation in suckled beef cows

2008 ◽  
Vol 39 (2) ◽  
pp. 496-501 ◽  
Author(s):  
Luiz Felipe Kruel Borges ◽  
Rogério Ferreira ◽  
Lucas Carvalho Siqueira ◽  
Rodrigo Camponogara Bohrer ◽  
Jacson William Borstmann ◽  
...  
Keyword(s):  
Artificial Insemination ◽  
Transrectal Ultrasound ◽  
Beef Cows ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Timed Artificial Insemination ◽  
Average Size ◽  
Vaginal Device ◽  
Estrous Behavior ◽  
Follicular Dynamics

The aim was to develop a timed artificial insemination (TAI) system in suckled beef cows. Cows (n=227), 60-80 days postpartum, received estradiol benzoate (5mg) and a vaginal device containing 250µg of medroxyprogesterone acetate (MPA; day 0). On day six, cloprostenol (125µg) and eCG (400IU) were administrated and calves were weaned for 88h. The devices were removed on day seven (BioRep group) or on day eight (TAI group). All cows of TAI group and cows of BioRep group that did not exhibit standing estrus received GnRH (100µg) on day 9. In experiment I, the follicular growth was monitored daily by transrectal ultrasound exams, from day 6 to day 9. The average size of the dominant follicle on day nine was 11.1±0.99mm (BioRep, n=7) and 11.5±0.65mm (TAI, n=7) and all animals ovulated. In experiment II, the BioRep group cows (n=106) were observed for estrous behavior after withdrawal of the device, twice a day for 48h, and inseminated 12h after detection. In the TAI group (n=107), the devices were withdrawn on day eight and after 24h these cows and those from the BioRep group, which were not stand in estrus, received 100µg of GnRH and TAI 16h later. The pregnancy rates were 57.6% (BioRep) and 52.3% (TAI). In conclusion, an increase on MPA exposure time did not affect the follicular dynamics and pregnancy rates and allow TAI without estrous observation. Furthermore, the treatment for eight days provides an efficient TAI system in suckled beef cows.

Response of beef heifers and non-suckling beef cows to different oestrous synchronization protocols

2002 ◽  
Vol 74 (3) ◽  
pp. 547-552 ◽  
Author(s):  
D. Cavestany ◽  
N. Negrin ◽  
R. Negrin ◽  
J. F. Groth
Keyword(s):  
Beef Cattle ◽  
Medroxyprogesterone Acetate ◽  
Artificial Insemination ◽  
Experimental Period ◽  
Fixed Time ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Gnrh Analogue ◽  
Beef Heifers

AbstractThe objective was to evaluate different oestrous synchronization schemes in beef cattle under range conditions. In experiment 1, 202 heifers averaging 26 months of age were assigned randomly to three treatments: (a) GnRH-PG. (no. = 44) day 0 (D0): injection of GnRH; D7: injection of PGF2α; D0 to D25 oestrous detection (OD) and artificial insemination (AI); (b) OD-PG. (no. = 45) D0 to D4; OD + AI; D5: injection of PGF2α; D5 to D25 OD + AI; and (c)Ovsynch. (no. = 113) D0: injection of GnRH; D7: injection of PGF2α; D9: injection of GnRH and 16 h later AI at fixed time. In experiment 2, 318 non-suckling cows were assigned randomly to three treatments: (a) GnRH-PG. (no. = 106) D0: injection of GnRH; D7: injection of PGF2α; D0 to D25 OD + AI; (b) GnRH-MAP-PG. (no. = 106) D0: injection of a GnRH analogue and insertion of an intravaginal sponge impregnated with 250 mg of medroxyprogesterone acetate; D7: injection of PGF2α and sponge withdrawal; D0 to D25 OD + AI; (c) controls. (no. = 106) OD and AI. The experimental period lasted 25 days and, with exception of the Ovsynch treatment, oestrous detection was carried out twice a day (a.m./p.m.) and inseminations performed 12 h later. The pregnancy rates assessed by ultrasonography 30 days after AI were: experiment 1: (a) 30·0%; (b) 28·6% and (c) 62·3% (P < 0·05); experiment 2: (a) 60·2%; (b) 57·8% and (c) 45·5% (P < 0·05). It is concluded that in heifers and non-suckling cows, oestrous synchronization treatments result in higher pregnancy rates. In non-suckling cows, the addition of a progestagen did not improve the response.

Estrous synchronization and fertility of cross-bred dairy cows using prostaglandin F2α and gonadotropin releasing hormone

2021 ◽  
pp. 171-175
Author(s):  
Abubakr O. Ismail ◽  
◽  
Erneo B. Ochi ◽  
Ambrose S. Jubara ◽  
Bakri Ahmed A/Rahim ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Artificial Insemination ◽  
Prostaglandin F2α ◽  
Fixed Time ◽  
Gonadotropin Releasing Hormone ◽  
Pregnancy Rates ◽  
Releasing Hormone ◽  
Treatment Groups ◽  
Estrous Synchronization ◽  
Descriptive Statistical Analysis

A comparative hormonal study of prostaglandin, gonadotropin releasing hormone and their combination was conducted on 30 randomly selected cross-bred dairy cows of SEMEX project for artificial insemination in Hillat Kuku, Khartoum North, Sudan. The study attempts to determine the response of the animals to hormonal induction and synchronization of estrous as well as fertility following fixed time artificial insemination. Three treatment groups of 10 cows each were undertaken. Groups 1, 2 and 3 involved administration of prostaglandin F2α (PGF2α), gonadotropin releasing hormone (GnRH) and a combination of PGF2α + GnRH, respectively. Descriptive statistical analysis was performed. The results revealed that all the three protocols induced and synchronized estrous were almost synchronous in all the treated groups. However, protocol 3 revealed a significantly (p<0.05) better result of 70% pregnancy rate compared to other two protocols that equally provided 50% pregnancy rates. The study resolves that protocol 3 be highly recommended to change the mindset of farmers about the spread of reproductive technology in Sudan. Protocols 1 and 2 provided acceptable pregnancy rates that can be enhanced with the improvement of management.

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