scholarly journals 142 Evaluation of estrus detection patches as a tool to classify postpartum beef cows as estrous cycling or anestrous prior to the start of the breeding season

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 116-117
Author(s):  
Emily G Smith ◽  
Rachael C Bonacker ◽  
Carson M Andersen ◽  
Jordan M Thomas

Abstract Estrus detection patches were evaluated as a tool to classify postpartum cows as estrous cycling or anestrous at the start of the breeding season. EstrotectTM Breeding Indicators were applied to 257 postpartum beef cows in three locations 25 days prior to the start of estrus synchronization. Coincident with the start of estrus synchronization, patches were scored using a 1 to 4 scale (1 = 0–25%; 2 = 25–50%; 3 = 50–75%; 4 = 75–100%) with scores of 3 or 4 considered activated. Blood samples were collected from each cow 10 days prior to, and at the start of the estrus synchronization. Serum progesterone concentrations were determined via radioimmunoassay; cows were considered estrous cycling if one or both samples exceeded a concentration of 0.5 ng/ml. Based on progesterone, 54.9% of cows were estrous cycling at the start of estrus synchronization. When missing patches were considered inconclusive results, use of patches to infer estrous cyclicity resulted in 85.0% sensitivity and 79.2% specificity with a positive predictive value of 87.2%. However, 75.1% of all cows presented with missing patches at the start of synchronization. If missing patches were considered activated, sensitivity was 95.7%, but specificity (16.4%) and PPV (58.2%) were poor, as 47.6% of cows presenting with missing patches were anestrous based on progesterone. Across all cows, pregnancy rate to AI was 58.0% (149/257). Cows with activated patches that were classified as false positives based on serum progesterone concentrations achieved a 71.4% (5/7) pregnancy rate to AI, raising questions as to whether sensitivity was underestimated due to inherent Type II errors in classification of cyclicity via progesterone. In summary, estrus detection aids are a sensitive tool to identify estrous cycling postpartum cows prior to the start of the breeding season; however, poor specificity and patch retention are limitations for this application.

2019 ◽  
Vol 59 (2) ◽  
pp. 225 ◽  
Author(s):  
Walvonvitis Baes Rodrigues ◽  
Jean do Prado Jara ◽  
Juliana Correa Borges ◽  
Luiz Orcirio Fialho de Oliveira ◽  
Urbano Pinto Gomes de Abreu ◽  
...  

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.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 30-31
Author(s):  
Vitor R G Mercadante ◽  
Robin R White ◽  
Heather L Bradford ◽  
Nicholas W Dias ◽  
Claire Timlin ◽  
...  

Abstract The objective of this study was to assess how well estrus detection patch readings correlated to successful AI breedings and to characterize the within-cow repeatability of estrus detection patch readings across breeding seasons. Data from the Virginia Department of Corrections beef cattle herds were collated for 7 locations over 7 years, with 2 calving seasons per year. Data from Spring of 2011 were missing. The full dataset contained 19,253 individual animal observations, of which 2,389 observations were omitted for failure to report estrus detection patch data. The relationship between estrus patch reading and pregnancy rate to fixed-time AI and subsequent natural service pregnancy rate was assessed by calculating the sensitivity and specificity of patch readings within each location during each breeding season. A true positive was defined as a patch activating and a cow being confirmed pregnant. A true negative was a patch remaining in the non activated state and a cow being confirmed open. A false positive was defined as a patch activating and a cow being confirmed open. A false negative was a patch failing to activate and a cow being confirmed pregnant. Pregnancy rate to AI sensitivity ranged from 0.2 to 1 with a mean of 0.583. Specificity ranged from 0 to 1 with a mean of 0.525. Subsequent natural service pregnancy rate), ranges in sensitivity (0.197 to 1.00, mean 0.563) and specificity (0 to 1, mean 0.545) were similar. Of the 6,249 animals with usable patch data, 934 never presented with an activated patch and 2,064 presented with an activated patch every breeding season. The remaining 3,251 animals averaged presenting with an activated patch 47% of the time and a non-activated patch 46% of the time. Odds of getting pregnant by AI for cows that always flag with the heat patch were 0.415.


2010 ◽  
Vol 22 (1) ◽  
pp. 179
Author(s):  
L. D. P. Sinedino ◽  
B. T. Gerhardt ◽  
A. P. Dourado ◽  
L. A. G. Nogueira

The objective of this paper was to compare 3 bovine AI protocols, evaluating the cost of each treatment and the pregnancy rates obtained, to demonstrate the importance of routine utilization of estrus synchronization techniques. The experiment was conducted in the Farm School of Cachoeiras de Macacu of the Federal Fluminense University, in the state of Rio de Janeiro, during the period from 2006 to 2007 (August to June). One hundred sixteen crossbred female Holstein-Zebu dairy cows in cycle, with body condition between 2.5 to 4 (on a scale from 1 to 5), were selected and divided randomly in 3 groups (G). Animals in G1 [n = 60; 21 heifers (H), 13 primiparous (P), and 26 multiparous (M)], with palpable corpus luteum, received 25 mg of prostaglandin F2 intravulvar, and AI was done 12 h after estrus detection. For animals in G2 (n = 30; 11 H, 6 P, and 13 M) an intravaginal progesterone device (CIDR®, Pfizer Animal Health, New York, NY, USA) was inserted and 2 mg of estradiol benzoate (EB) was administered i.m. on Day 0. On Day 8 the device was removed and 25 mg of prostaglandin was administered i.m. on Day 9, 2 mg of EB was administered, and 30 h later, timed AI of all animals was performed. For G3 (n = 26; 9 H, 5 P, and 12 M), the protocol used was similar to that for G2, except that on Day 8 400 IU of eCG was administered (in addition to the removal of the device) and on Day 9 the dose of EB was reduced to 1 mg and timed AI was done 27 h later. AI was done with semen from 2 sires with proven fertility, by the same technician. The pregnancy diagnoses were done on Day 45 by palpation per rectum and transrectal ultrasonography. The cost-benefit relation was calculated according to the cost of pharmaceuticals multiplied by the number of animals in each experimental group divided by the number of pregnancies obtained in each one, without considering the manual labor costs in all the groups and considering 3 uses of the CIDR. The statistical analyses were done using chi-square test. The pregnancy rate obtained in G2 (60%, 18/30) was superior to that in G1 (30%, 18/60) (P < 0.05), demonstrating the efficiency of the treatment that utilized progesterone. G3 (53.85%, 14/26) was similar (P > 0.05) to G2, despite the fact that the eCG was added in this group. In reference to cost-benefit, considering only the pharmaceuticals costs and the value for pregnancy obtained in each group, the costs found, respectively, were G1 U$7.02 and U$23.66; G2 U$28.57 and U$47.59; and G3 U$47.96 and U$89.05. The lowest cost in the estrus synchronization was based on the use of prostaglandins alone; the use of progesterone increased the synchronization cost, but also increased the pregnancy rate and eliminated the need for estrus observation. The addition of eCG in cows that are cycling does not necessarily demand a increase in pregnancy rate. Failure in estrus detection, using prostaglandin alone, increased the interval from calving, causing a daily loss in milk production, which justified the investment in protocols of estrus and ovulation synchronization, contributing to increase the reproductive efficiency of a dairy cow herd.


2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 121-121
Author(s):  
R. C. de Souza ◽  
R. C. Souza ◽  
A. C. B. P. Tavares ◽  
G. C. V. de Oliveira ◽  
L. A. M. de Souza ◽  
...  

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 117-117
Author(s):  
Stefania Pancini ◽  
John Currin ◽  
Jamie L Stewart ◽  
Sherrie Clark ◽  
Tracey Redifer ◽  
...  

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.


1999 ◽  
Vol 79 (1) ◽  
pp. 39-43 ◽  
Author(s):  
J. Thundathil ◽  
J. P. Kastelic ◽  
W. O. Olson ◽  
R. B. Cook ◽  
R. J. Mapletoft

Three experiments were conducted with suckled crossbred beef cows to determine the efficacy of various short-term regimens for synchronizing estrus or ovulation and to determine whether feeding melengestrol acetate (MGA) after timed AI will increase pregnancy rate. In exp. 1, all cows (n = 141) were given 0.5 mg MGA head−1 d−1 for 7 d (days 1 to 7), 1 or 5 mg E17β (and 100 mg progesterone) or 100 µg GnRH on day 1, and 500 µg cloprostenol on day 7. There were no significant differences among groups for estrous or synchronized conception rates (average, 84.4 and 52.1%, respectively). With an identical protocol in exp. 2 (78 cows), by day 11, cows given 5 mg E17β had the highest estrous and synchronized pregnancy rates (65.4 and 42.3%), compared to 1 mg E17β (46.2 and 15.4%) and GnRH (34.6 and 11.5%). Cows not detected in estrus were timed-inseminated and given 100 µg GnRH, 100 h after cloprostenol. There were no significant differences among groups for synchronized conception rate to timed AI (65.0%) or synchronized pregnancy rate to all inseminations (56.4%). Overall, 5 mg E17β gave the most consistent results. In exp. 3, 84 cows were given 100 µg GnRH on days 1 and 9, 500 µg cloprostenol on day 7, and were timed-inseminated on day 10. Half were fed MGA (0.5 mg head−1 d−1) on days 16 to 22, but the pregnancy rate was not different from that in the remaining cows (55.0 versus 47.8%, P > 0.5). Key words: Ovary, follicles, estrus synchronization, beef cows


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 362-363
Author(s):  
Reinaldo F Cooke ◽  
Nicola Oosthuizen ◽  
Kelsey Schubach ◽  
Alice Brandão ◽  
Ramiro Oliveira Filho ◽  
...  

Abstract To evaluate the impact of estrus expression and intensity on parameters associated with reproductive performance, 219 lactating, multiparous Bos taurus-influenced beef cows were enrolled in this study. Cows were exposed to an estrus synchronization protocol, where they received a 100-µg injection of GnRH and a CIDR insert on d -10, a 25-mg injection of PGF2a at CIDR removal on d -3, and an injection of GnRH 60–66 h following CIDR removal at fixed-time AI (TAI; d 0). Cows were fitted with a pedometer behind their right shoulder on d -10, and an estrus detection patch was applied to their tail-head on d -3. Estrus expression was defined as removal of &gt; 50% of the rub-off coating from the patch on d 0. Net physical activity during estrus was calculated by subtracting daily activity during the non-estrus period (d -10 to -3) from activity during the expected estrus period (d -3 to 0). Cows were classified into 3 groups: cows that did not express estrus (NOESTR; n = 119), cows that expressed estrus with net physical activity greater than the median (HIESTR; n = 50), and the remaining cows (LWESTR; n = 50). Ultrasonography was performed on d -3, 0, and 7 to determine the presence and size of ovarian structures. Pregnancy diagnosis was performed 29 d after TAI. Net physical activity was greater in HIESTR compared to both LWESTR and NOESTR (P &lt; 0.01). Dominant follicle size was greater in HIESTR compared to both LWESTR and NOESTR (P &lt; 0.01). Furthermore, HIESTR had greater corpus luteum volume on d 7 than LWESTR and NOESTR (P &lt; 0.01). Pregnancy rates to AI (PR/AI) were greater in HIESTR and LWESTR compared to NOESTR (P &lt; 0.01). In conclusion, cows that expressed estrus at a greater intensity had improved ovarian dynamics. Additionally, cows that exhibited estrus had greater PR/AI compared to non-estrual cows.


2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 45-45
Author(s):  
Stefania Pancini ◽  
Jhon F Currin ◽  
Jamie L Stewart ◽  
Sherrie Clark ◽  
Tracey Redifer ◽  
...  

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.


2010 ◽  
Vol 39 (5) ◽  
pp. 1058-1067 ◽  
Author(s):  
Ricardo Zambarda Vaz ◽  
José Fernando Piva Lobato

This study evaluated body development and reproductive performance of beef cows whose calves were submitted to early weaning (76 days of age), or conventional weaning (148 days of age). It was used 141 Braford cows that calved in 2004, 2005, and 2006 to evaluate weight at calving at 76 days, weight at calving at 148 days, weight at the beginning and end of the breeding season, variation of the average daily weight, body condition, pregnancy rate, and calving interval. Dams of calves weaned at 148 days of age showed daily weight gain higher body weight and better body condition at 148 days of age. The weights at the end of breeding season and average weight gain during the breeding season were higher in early weaning cows than in conventional cows. Pregnancy rate of early weaning cows (86.34%) was higher than those submitted to weaning at conventional age (55.45%). Pasture interval was similar among early weaning cows and conventional weaning cows. The best benefit on reducing weaning age in pregnancy rate was in primiparous cows. There was significant interaction between weaning age and the year for calving interval and milk production. The early weaning of calves carried out at 76 days of age allows cows to better weight recovery in the post-weaning and breeding periods, improving their body condition and consequently increasing pregnancy rate regarding to cows whose calves suckled until 148 days of age.


2017 ◽  
Vol 73 (8) ◽  
pp. 479-482 ◽  
Author(s):  
Mushap Kuru ◽  
Osman Sogukpinar ◽  
Mustafa Makav ◽  
Nebi Cetin

This study was aimed at determining the effect of barium selenate injections on the fertility of Pirlak ewes which had been subjected to progesterone-assisted estrus synchronization during the non-breeding season. A total of 150 Pirlak ewes between the ages of 2 and 5 years were used in the study. Sponges containing progesterone were inserted into the vaginas of the ewes for 11 (groups I and III) or 14 days (groups II and IV) for the purpose of estrus synchronization, and 500 IU equine chorionic gonadotropin (eCG) was administered on the day of sponge removal. In addition, barium selenate was injected s.c. immediately before estrus synchronization protocol in groups I and III. After the sponges had been removed, estrus was observed for four days. The ewes were mated with fertile rams. The pregnancy was determined by transrectal ultrasonography 30 days after mating. It was observed that the estrus rate, pregnancy rate, conception rate, lambing rate, twinning rate, and litter size were not statistically different (P > 0.05) between the groups, but estrus onset was different (P < 0.001). In conclusion, barium selenate injections did not affect the fertility parameters before progesterone-assisted synchronization was applied to the Pirlak ewes during the non-breeding season


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