scholarly journals Evaluation of synchronization protocols and methods of early pregnancy diagnosis in dairy cattle

2021 ◽  
Vol 50 (6) ◽  
Author(s):  
A.H. Shahzad ◽  
A. Sattar ◽  
N. Ahmad ◽  
I. Ahmad ◽  
M.S. Yousaf ◽  
...  

The studies aimed to evaluate the pregnancy rate (PR) for timed artificial insemination (TAI) after G7G-Ovsynch, modified G7G-Ovsynch (MG7G-Ovsynch) and Ovsynch protocols and to assess the accuracy of using pregnancy-associated glycoproteins (PAGs) and plasma progesterone (P4) in pregnancy diagnosis compared with ultrasonography (US). In study 1, Holstein cows (n = 37) were bred by TAI following the G7G-Ovsynch protocol (n = 19) or MG7G-Ovsynch (n = 18). Pregnancy was evaluated by US at days 31, 59, and 87 after breeding. The PR was not different for the G7G-Ovsynch and MG7G-Ovsynch. Blood and milk samples were collected on day 3 after insemination and then weekly through day 59 post TAI in cows diagnosed as not pregnant on day 31 and through day 87 in pregnant cows. PAGs were measured using ELISA and P4 by radioimmunoassay (RIA). In the second study, Holstein cows (n = 212) were bred by TAI following G7G-Ovsynch protocol (n = 110) or standard Ovsynch (n = 102). Cows were subjected to pregnancy diagnosis on days 30, 60, and 90. A subset (n = 15 in each group) was subjected to blood and milk samples on days 30, 45, 60, 75, and 90 to measure PAGs and P4. In study 2, PR was not significantly different between synchronization protocols on days 30, 60, and 90. Pregnancy loss averaged 15% between day 30 and day 90. The use of PAGs and P4 proved equally effective in diagnosis of pregnancy. Thus, G7G-Ovsynch was deemed the protocol of choice in postpartum cows, and PAGs assayed in milk or plasma could be used to diagnose pregnancy.

2013 ◽  
Vol 46 (3) ◽  
pp. 102-104 ◽  
Author(s):  
Iva Skalova ◽  
Tamara Fedorova ◽  
Karolina Brandlova

Abstract Saliva sampling is a non-invasive, simple and low-cost procedure. The aim of this study was to confirm the presence and changes of saliva crystallization in domestic cattle during synchronized oestrous cycle and early pregnancy. We verified saliva crystallization as a method for early pregnancy diagnosis. Eight Holstein cows were included into the research. The samples were collected daily from 16th day before to 34th day after artificial insemination (in total 51 days). We observed the following types of crystallization: none, dotted, branch-like, fir-like, fern-like and combinations of them and an atypical pattern. We confirmed the presence of saliva crystallization in cattle and its changes during oestrus synchronization process, insemination and post-insemination periods. We found significant differences in pregnant and non-pregnant animals between 20th and 29th day after insemination. We concluded that pregnancy diagnosis by saliva crystallization might be possible but the practical application of this method is currently unfeasible.


2021 ◽  
Vol 73 (1) ◽  
pp. 41-48
Author(s):  
J.H.A. Weiller ◽  
M.V.C. Ferraz Júnior ◽  
F. Jacobs Dias ◽  
G.Y. Hattori

ABSTRACT This study aimed to determine the efficiency of estradiol cypionate (EC) as an ovulation inducer in a Timed Artificial Insemination protocol. 69 buffalo cows received an intravaginal progesterone device and 2mg of estradiol benzoate (EB) at D0. On D9, the intravaginal device was removed and 0.53mg of prostaglandin (PGF2α) and 400UI of equine chorionic gonadotrophin (eCG) were applied. The cows were distributed into two groups: the first group received 1mg of EC (ECG) in D9, and the second group received 1mg of EB (EBG) in D10. Inseminations occurred on D11. Ovarian activity and pregnancy diagnosis were analyzed by ultrasonography. There was no difference (P>0.05) in follicular diameter (9.6 ± 0.89mm vs. 10.7 ± 1.12mm; P=0.06), in ovulation rate (90.9% vs. 90.9%; P=1) and pregnancy rate (58.8% vs. 62.9%; P=0.79), however, buffalo cows from the ECG treatment have less time between P4 removal and ovulation when compared to EBG buffalos (37.4h vs. 52.8h; P=0.001), respectively. Thus, it was concluded that the implantation of TAI in the floodplain of Amazonas is feasible and the use of EC results in successful rates, similar to EB.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 124-124
Author(s):  
Vitor R G Mercadante ◽  
Nicholas W Dias ◽  
Claire L Timlin ◽  
Stefania Pancini

Abstract Over the last four decades, several advances in reproductive biotechnologies have helped beef producers improve genetic traits of their cattle, tighten the breeding season and shorten the calving season, leading to an increase in overall profitability of cow-calf production systems. However, even with these advancements, reproductive failure and embryo mortality are still a major cause for economic loss in beef production. Recently, we projected a loss of $6.25 per exposed cow for every 1% decrease in pregnancy rate, with an estimated gross loss of $2.8 billion annually in the United States due to pregnancy failure in beef females. It is estimated that 75 to 80% of embryonic loss occurs by d 20 of gestation; a large portion of these losses occur during the first week of gestation and likely are caused by issues relating to fertilization failure, incompetence of embryos originated from poor quality oocytes and suboptimal uterine conditions. Furthermore, within the first month of gestation, nearly half of all cows submitted to breeding will not be pregnant 30 d later, and another 5% will lose their pregnancy by d 100 of gestation. In addition, breeding related costs, including bull purchase, breeding soundness exam, estrous synchronization, semen purchase, labor associated with artificial insemination and pregnancy diagnosis, are estimate at $65 per cow exposed. Assuming a 90% pregnancy rate at the end of the breeding season, and a scenario where all 30 million beef females in the U.S. are exposed to fixed-time artificial insemination and undergo one pregnancy diagnosis, the added lost revenue of not producing a live calf to sell at weaning and the cost of breeding, would represent a loss of over $21 billion annually in the United States. Strategies that reduce pregnancy loss in beef cattle are essential to improve productivity and profitability of cow-calf production systems.


Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 758
Author(s):  
Donato de Nicola ◽  
Francesco Vinale ◽  
Angela Salzano ◽  
Giada d’Errico ◽  
Anastasia Vassetti ◽  
...  

This study aimed to identify potential biomarkers for early pregnancy diagnosis in buffaloes subjected to artificial insemination (AI). The study was carried out on 10 pregnant and 10 non-pregnant buffaloes that were synchronized by Ovsynch-Timed Artificial Insemination Program and have undergone the first AI. Furthermore, milk samples were individually collected ten days before AI (the start of the synchronization treatment), on the day of AI, day 7 and 18 after AI, and were analyzed by LC–MS. Statistical analysis was carried out by using Mass Profile Professional (Agilent Technologies, Santa Clara, CA, USA). Metabolomic analysis revealed the presence of several metabolites differentially expressed between pregnant and non-pregnant buffaloes. Among these, a total of five metabolites were identified by comparison with an online database and a standard compound as acetylcarnitine (3-Acetoxy-4-(trimethylammonio)butanoate), arginine-succinic acid hydrate, 5′-O-{[3-({4-[(3aminopropyl)amino]butyl}amino)propyl]carbamoyl}-2′-deoxyadenosine, N-(1-Hydroxy-2-hexadecanyl)pentadecanamide, and N-[2,3-Bis(dodecyloxy)propyl]-L-lysinamide). Interestingly, acetylcarnitine was dominant in milk samples collected from non-pregnant buffaloes. The results obtained from milk metabolic profile and hierarchical clustering analysis revealed significant differences between pregnant and non-pregnant buffaloes, as well as in the metabolite expression. Overall, the findings indicate the potential of milk metabolomics as a powerful tool to identify biomarkers of early pregnancy in buffalo undergoing AI.


2008 ◽  
Vol 88 (3) ◽  
pp. 457-461
Author(s):  
M. Aali ◽  
T. Pretheeban ◽  
G. Giritharan ◽  
R. Rajamahendran

Peripheral progesterone (P4) concentrations as well as pregnancy rates (PR) between cows treated with Ovsynch or CIDR ovulation synchronization/TAI protocols were compared. Two hundred and twenty-seven postpartum lactating Holstein cows were randomly assigned to Ovsynch (n = 111) or CIDR (n = 116) ovulation synchronization/TAI protocols. Pregnancy was diagnosed by ultrasonography at day 35 after TAI and later confirmed by rectal palpation at day 60 post TAI. Milk samples were taken from the beginning of treatment (day -10) until day 35 after TAI (day 0) for P4 determination. Pregnancy rates for Ovsynch and CIDR groups of cows were 31 and 41%, respectively. The PR of ovulation synchronized cows for Ovsynch and CIDR groups were 49 and 69%, respectively. Progesterone levels during the sampling period were similar (P > 0.05) between Ovsynch and CIDR treated cows. Key words: Pregnancy rate, progesterone, Ovsynch, CIDR, cows


2021 ◽  
Author(s):  
Sajjad Haider ◽  
Ghazanfar Ali Chishti ◽  
Muhammad Usman Mehmood ◽  
Muhammad Ameen Jamal ◽  
Khalid Mehmood ◽  
...  

Abstract The present study aimed to compare the pregnancy rates at the optimal time of artificial insemination in a 7-day CIDR Co-synch in Nili Ravi buffalo heifers. Forty Nili Ravi buffalo heifers were randomly separated into two treatments based on artificial insemination (A.I.) timing (72 vs 84 hours). All heifers were subjected to controlled internal drug release (CIDR), containing 1.38 grams of progesterone for 7 days. On CIDR removal, both treatments received 150 µg of prostaglandin intramuscularly. In 7-day CIDR Co-synch (n = 20), animals were injected 100 µg of GnRH intramuscularly and inseminated concurrently at 72 hours after CIDRs removal. The remaining half (n=20) were injected and inseminated concurrently at 84 hours of CIDRs removal. Pregnancy diagnosis was performed after 40 days of timed artificial insemination (TAI). The follicular growth rate in 7-day CIDR Co-synch was more significant at 84 than 72 hours. The interval from GnRH/A.I. to ovulation in 7-day CIDR Co-synch was significantly (P < 0.05) differ between 72 and 84 hours. Pregnancy rates were considerably higher in buffalo heifers inseminated at 84 hours (65%) than 72 hours (25%) in 7-day CIDR Co-synch treatment. In conclusion, the buffalo heifers treated with CIDR Co-synch based protocols in relation to TAI at 84 hours improves follicular growth rate, interval from GnRH/A.I. to ovulation, and pregnancy rate.


2021 ◽  
Vol 92 (1) ◽  
Author(s):  
Peng Zheng ◽  
He Huang ◽  
Xiaoyu Li ◽  
Fushuo Huang ◽  
Samson Olugbenga Adeniran ◽  
...  

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 &lt; 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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