Fixed-time AI pregnancy rate following insemination with frozen-thawed or fresh-extended semen in progesterone supplemented CO-Synch protocol in beef cows

The objective of this trial was to evaluate different post-timed artificial insemination (TAI) reproductive managements in postpartum beef cows to produce crossbred calves from artificial insemination (AI). Nellore cows (n = 607), with 45 days postpartum, were inseminated at a fixed time, using a protocol that included an intravaginal progesterone-releasing device along with oestradiol benzoate, prostaglandin, equine chorionic gonadotropin, and oestradiol cypionate, followed TAI 48 h post-device removal. Four post-TAI treatments were evaluated: in CONTROL (T1, n = 161), cows were exposed to Nellore clean-up bulls until the end of the breeding season (75 days). In OBSERVATION (T2, n = 132), heat detection was performed for 15–25 days post-TAI, followed by AI. In RESYNC22 (T3, n = 157) and RESYNC30 (T4, n = 157), resynchronisation started after 22 or 30 days, following second TAI at Day 32 or 40 days after first TAI. In T2, T3 and T4, after the second AI, cows were exposed to Nellore clean-up bulls until the end of the breeding season (75 days). The pregnancy rate (PR) for the first TAI did not differ (54.6%, 53.0%, 59.2%, and 51.6% for CONTROL, OBSERVATION, RESYNC 22, and RESYNC 30, respectively; P = 0.66), and no difference was observed for the second TAI (RESYNC 22 = 45.31% and RESYNC30 = 46.05%; P = 0.137), in the PR at the end of the breeding season (86.33%, 86.36%, 78.98%, and 81.52%, P = 0.43), or embryonic losses (4.54%, 2.85%, 6.45% and 7.40%, respectively; P = 0.61), but the percentage of crossbred pregnancy was higher in groups with resynchronisation (RESYNC22 and RESYNC30) than CONTROL and OBSERVATION (98.38%, 90.62%, 63.30%, 78.95%, P < 0.001). In conclusion, resynchronisation programs of 22 or 30 days are more efficient to produce AI products, and the final pregnancy rate is similar among the treatments, differing only in the amount of calves produced by AI.

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10 INFLUENCE OF ADMINISTRATION OF HUMAN CHORIONIC GONADOTROPIN ON DAY 4 AFTER FIXED-TIME AI ON CORPUS LUTEUM SIZE, FUNCTION, AND PREGNANCY RATE IN BEEF COWS

Reproduction Fertility and Development ◽

10.1071/rdv26n1ab10 ◽

2014 ◽

Vol 26 (1) ◽

pp. 119

Author(s):

J. B. S. Borges ◽

D. X. Thedy

Keyword(s):

Corpus Luteum ◽

Pregnancy Rate ◽

Fixed Time ◽

Beef Cows ◽

Pregnancy Rates ◽

Control Group ◽

Chi Square ◽

Prostaglandin F2a ◽

Successful Establishment ◽

Early Rise

Successful establishment of pregnancy in the cow depends on early rise of progesterone (P4) to improve embryo development. The present study was carried out to determine the corpus luteum (CL) function and pregnancy rate following the administration of 1.500 IU of hCG in suckled beef cows on Day 4 after fixed-time AI (FTAI). Crossbred Angus cows (n = 429), 40 to 70 days postpartum, were synchronized using 2 mg of oestradiol benzoate (EB) i.m. and an intravaginal progesterone-releasing device containing 1 g of P4 for 7 days. At device removal, prostaglandin F2a (150 mg of D-cloprostenol) was injected i.m.; 24 h later, 1 mg of EB was given and the FTAI were done 30 to 36 h after EB using semen of just 1 bull. Cows were assigned alternatively to receive 1.500 IU of hCG i.m. (n = 200) or 1 mL of saline i.m. (n = 229) on Day 4 after FTAI. Ovaries were examined by transrectal ultrasonography (n = 71) on Days 4 and 7 to detect the presence and to measure the area of CL. Blood samples were collected on Days 4, 7, 10, 14, and 30 post-oestrus to determine P4 concentration by RIA. Pregnancy diagnoses were done 30 days after FTAI. The effects of treatments on CL area and serum P4 levels were analysed by ANOVA (Proc GLM, SAS Institute Inc., Cary, NC, USA) and pregnancy rates compared by chi-square (Proc CATMOT, SAS). The induction of accessory CL determined on Day 7 was 44% in cows treated with hCG and not observed in the control group. The area of the CL on Day 7 was significantly higher (P < 0.01; 3.37 ± 2.56 v. 2.56 ± 0.22 cm2) in the hCG group. Despite the increase in CL size, the mean levels of P4 on Days 4, 7, 10, 14, and 30 post-AI indicated no difference (P > 0.05) in CL function between control and hCG-treated cows. On Day 30, pregnancy rates were not different (P = 0.08), at 46.7 and 55% for control and hCG-treated cows, respectively. In conclusion, administration of 1.500 IU of hCG on Day 4 post-FTAI did not improve pregnancy rate in suckled beef cows.

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156 Injectable trace mineral supplementation on grazing beef cows: effect on overall mineral status and fertility

Journal of Animal Science ◽

10.1093/jas/skaa278.213 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 117-117

Author(s):

Stefania Pancini ◽

John Currin ◽

Jamie L Stewart ◽

Sherrie Clark ◽

Tracey Redifer ◽

...

Keyword(s):

Pregnancy Rate ◽

Body Condition Score ◽

Post Partum ◽

Fixed Time ◽

Beef Cows ◽

Negative Control ◽

Trace Mineral ◽

Mineral Status ◽

Beef Cow ◽

Estrus Detection

Abstract The objective of this study was to evaluate the effect of two doses of an injectable multi-mineral complex supplementation on beef cow fertility and overall mineral status. A total of 986 Angus crossbred multiparous cows at 8 locations in Virginia were enrolled in a 7-day CO-Synch+CIDR fixed-time artificial insemination (FTAI) protocol, followed by natural service for an approximately 70 d breeding season. All cows had ad libitum access to water, mineral blocks, and diet composed of hay, grass, sudangrass, sorghum grain and commodity pellets, depending on location. Approximately 30 days before calving (d -120, day of AI is d 0) cows were randomly assigned to one of two treatments: 1) Two doses (6 mL) of Multimin® 90 (Multimin USA, Ft. Collins, CO) at d -120 and d -10 (MIN; n = 494); or 2) a negative control with no trace mineral injection (CTRL; n = 492). Body condition score was recorded on d -10, 60 and 120. Estrus detection was recorded at d 0 using estrus detection patches. Pregnancy was diagnosed on d 60 and 120 by ultrasonography. Liver biopsies were collected on d -10 and 60 in a subgroup of 60 cows equally distributed between treatments and among all locations. No differences between treatments were detected in days post-partum (P = 0.66), BCS (P = 0.24) and estrus expression (P = 0.11). Mineral status of copper, manganese, selenium or zinc was similar between treatments before (P = 0.20) and after treatment (P = 0.17). No effect of treatment was detected in FTAI pregnancy rate (50.8%, P = 0.52) or overall pregnancy rate (89.6%, P = 0.64). Two doses of injectable trace mineral administrated approximately 30 days before calving and 10 days before FTAI did not improve pregnancy rate or overall mineral status in multiparous beef cows in Virginia.

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Effect of the ovulatory follicle diameter and progesterone concentration on the pregnancy rate of fixed-time inseminated lactating beef cows

Revista Brasileira de Zootecnia ◽

10.1590/s1516-35982012000400024 ◽

2012 ◽

Vol 41 (4) ◽

pp. 1004-1008 ◽

Cited By ~ 9

Author(s):

Luiz Francisco Machado Pfeifer ◽

Sofia del Carmen Bonilla de Souza Leal ◽

Augusto Schneider ◽

Eduardo Schmitt ◽

Marcio Nunes Corrêa

Keyword(s):

Pregnancy Rate ◽

Fixed Time ◽

Beef Cows ◽

Progesterone Concentration ◽

Follicle Diameter ◽

Ovulatory Follicle

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The use of insulin to improve fertility of timed-inseminated postpartum suckled beef cows

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2010001000023 ◽

2010 ◽

Vol 45 (10) ◽

pp. 1219-1221 ◽

Cited By ~ 2

Author(s):

Augusto Schneider ◽

Luiz Francisco Machado Pfeifer ◽

Eduardo Schmitt ◽

Ivan Bianchi ◽

Marcelo Brandi Vieira ◽

...

Keyword(s):

Pregnancy Rate ◽

Body Condition ◽

Chorionic Gonadotropin ◽

Artificial Insemination ◽

Body Condition Score ◽

Insulin Injection ◽

Fixed Time ◽

Beef Cows ◽

Condition Score ◽

Equine Chorionic Gonadotropin

The objective of this work was to evaluate the effect of insulin alone or in association with equine chorionic gonadotropin (eCG) on the fertility of postpartum beef cows subjected to synchronization. A total of 340 cows was subjected to fixed time artificial insemination. In the trial 1, the cows were subjected to temporary weaning (TW), while in the trial 2 the same protocol was tested without TW. The addition of an insulin injection to a progesterone/eCG-based protocol without TW increased the pregnancy rate of beef cows with body condition score (BCS) equal to or lower than 2.5. Insulin had no effect on cows submitted to TW or with BCS equal to or higher than 3.0.

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42 Effect of injectable trace mineral supplementation on beef cows fertility and overall mineral status

Journal of Animal Science ◽

10.1093/jas/skz397.103 ◽

2020 ◽

Vol 98 (Supplement_2) ◽

pp. 45-45

Author(s):

Stefania Pancini ◽

Jhon F Currin ◽

Jamie L Stewart ◽

Sherrie Clark ◽

Tracey Redifer ◽

...

Keyword(s):

Pregnancy Rate ◽

Post Partum ◽

Fixed Time ◽

Beef Cows ◽

Negative Control ◽

Trace Mineral ◽

Mineral Status ◽

Mineral Supplementation ◽

Estrus Detection ◽

Natural Service

Abstract The objective of this study was to evaluate the effect of an injectable multi-mineral complex supplementation on beef cows overall mineral status and fertility. This study involved 9 different locations in the state of Virginia and a total of 1,128 Angus crossbred multiparous cows. All cows had ad libitum access to forage and water, and received mineral supplementation in form of mineral blocks. All cows were enrolled in a 7-d CO-Synch + CIDR fixed-time AI (FTAI) protocol, followed by natural service for an approximately 70-d breeding season. At the initiation of the FTAI protocol (d 0) cows were stratified by days post-partum (82 ± 18 d) and randomly assigned to one of two treatments: 1) One dose of an injectable trace mineral containing zinc (60mg/ml), copper (15mg/ml), selenium (5mg/ml) and manganese (10mg/ml) on d 0 (n = 560; 1 ml/90 kg BW of Multimin® 90, Multimin USA, Ft. Collins, CO); or 2) a negative control with no trace mineral injection (n = 568). BCS was recorded at d 0, 61 and 121. Estrus detection was recorded at d 10 using an estrus detection patch. Pregnancy was diagnosed on days 71 and 131 by ultrasonography. Liver biopsies were collected on days 0 and 45 in a subgroup of 140 cows from both treatments and distributed among all locations. No differences between treatments were detected in days post-partum (P = 0.83), BCS (P ≥ 0.42) and estrus detection (P= 0.12), neither in mineral status of copper, manganese, selenium or zinc (P ≥ 0.28). No effect of treatment was detected (P ≥ 0.20) in AI pregnancy rate (57%) or overall pregnancy rate (93%). In conclusion, one dose of injectable trace mineral administrated 10 days before AI did not improve pregnancy rate or overall mineral status in multiparous beef cows enrolled in FTAI.

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Pregnancy rate after fixed-time artificial insemination of suckled beef cows subjected to a cosynch protocol with either buserelin or hCG as ovulation inducing agent

Livestock Science ◽

10.1016/j.livsci.2017.10.025 ◽

2017 ◽

Vol 206 ◽

pp. 141-147 ◽

Cited By ~ 1

Author(s):

Walter Schmitz ◽

Michael Kramer ◽

Georg Erhardt ◽

Matthias Gauly ◽

Marc-Antoine Driancourt ◽

...

Keyword(s):

Pregnancy Rate ◽

Artificial Insemination ◽

Fixed Time ◽

Beef Cows

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140 The combination of ß-carotene and vitamins improves the pregnancy rate at fixed time artificial insemination (FTAI) in grazing beef cows

Journal of Animal Science ◽

10.2527/asasann.2017.140 ◽

2017 ◽

Vol 95 (suppl_4) ◽

pp. 69-69

Author(s):

M. H. A. Colli ◽

W. A. Gonçales Junior ◽

J. C. Motta ◽

V. N. D. Gouvea ◽

T. S. Acedo ◽

...

Keyword(s):

Pregnancy Rate ◽

Artificial Insemination ◽

Fixed Time ◽

Beef Cows

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The combination of β-carotene and vitamins improve the pregnancy rate at first fixed-time artificial insemination in grazing beef cows

Livestock Science ◽

10.1016/j.livsci.2018.09.002 ◽

2018 ◽

Vol 217 ◽

pp. 30-36

Author(s):

Vinícius Nunes de Gouvêa ◽

Marcos Henrrique Alcantra Colli ◽

Walter Antonio Gonçales Junior ◽

Jéssica Cristina Lemos Motta ◽

Tiago Sabella Acedo ◽

...

Keyword(s):

Pregnancy Rate ◽

Artificial Insemination ◽

Fixed Time ◽

Beef Cows ◽

Β Carotene

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The effect of clitoral stimulation post artificial insemination on pregnancy rates of multiparous Bos indicus beef cows submitted to estradiol/progesterone-based estrus synchronization protocol

Journal of Animal Science ◽

10.1093/jas/skaa195 ◽

2020 ◽

Vol 98 (7) ◽

Author(s):

Ramiro V Oliveira Filho ◽

Reinaldo F Cooke ◽

Gustavo A de Mello ◽

Victor M Pereira ◽

Jose Luiz M Vasconcelos ◽

...

Keyword(s):

Pregnancy Rate ◽

Artificial Insemination ◽

Body Condition Score ◽

Bos Indicus ◽

Fixed Time ◽

Beef Cows ◽

Pregnancy Rates ◽

Estrus Synchronization ◽

Exit Velocity ◽

Clitoral Stimulation

Abstract Clitoral stimulation after artificial insemination (AI) in beef cattle is a common practice utilized by AI technicians; however, the effect of clitoral stimulation during fixed-time AI (TAI) is still unknown. The objective of the present experiment was to evaluate the effect of clitoral stimulation on temperament responses and pregnancy rates to TAI in Bos indicus beef cows. A total of 1,186 multiparous Nellore cows across three different locations were assigned to an estradiol/progesterone-based estrus synchronization + TAI protocol (day −11 to 0). Cows were randomly assigned to receive either 3 s of clitoral stimulation (n = 602) or no clitoral stimulation (n = 584) immediately after TAI (day 0). Cow body condition score (BCS) was recorded on day −11. Estrus expression was evaluated based on estrus detection visual aid patch activation on day 0 (estrus, ≥50% activated; no estrus, <50% activated). Temperament was assessed by individual chute score based on a 5-point scale before TAI, and individual exit velocity was measured after clitoral stimulation. Pregnancy diagnosis was performed 30 d after TAI via transrectal ultrasonography. Pregnancy rate to TAI was positively affected by BCS (P < 0.01) and estrus expression (P = 0.03). Pregnancy rates of cows receiving clitoral stimulation did not differ (P = 0.39) from cows non-stimulated (47.5 ± 4.6% vs. 44.3 ± 4.6%, respectively). No interaction of clitoral stimulation and estrus expression was observed (P = 0.26). Chute score was positively correlated to exit velocity (P < 0.01; r = 0.29); however, clitoral stimulation did not affect exit velocity (P = 0.86). In summary, pregnancy rates to TAI are influenced by various factors and multiple strategies have the potential to increase the fertility of beef cows submitted to TAI; however, clitoral stimulation of Bos indicus beef cows did not improve TAI pregnancy rate.

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