Factors affecting pregnancy rate to estrous synchronization and fixed-time artificial insemination in beef cattle1,2

2011 ◽  
Vol 89 (10) ◽  
pp. 3060-3068 ◽  
Author(s):  
S. E. Echternkamp ◽  
R. M. Thallman
2019 ◽  
Vol 22 (07) ◽  
pp. 118-122
Author(s):  
Haider R. Abbas ◽  
Hussein A. Khamees ◽  
Jawad K. Taher

Author(s):  
Abubakr O. Ismail ◽  
◽  
Erneo B. Ochi ◽  
Ambrose S. Jubara ◽  
Bakri Ahmed A/Rahim ◽  
...  

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.


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.


2020 ◽  
Vol 89 (4) ◽  
pp. 307-315
Author(s):  
Hasan Alkan ◽  
Huseyin Erdem

The aim of this study was to investigate the effects of hormonal support on the pregnancy rate in repeat breeder cows. Prostaglandin F2α + Ovsynch oestrus synchronization protocol was applied to the cows. Following the fixed time insemination (day 0), the cows were divided into 4 groups. In Group 1 (n = 42), progesterone releasing intravaginal device (PRID) was placed vaginally at 84 h and removed on the 9th day after the artificial insemination. In Group 2 (n = 40), the cows were administered human chorionic gonadotropin (hCG) on the 7th day. Group 3 (n = 45) was applied a combination of progesterone and hCG. Group 4 (n = 42) was not given any treatment. Blood samples were collected from all cows 4 times on days 3.5, 7, 12, and 18 to evaluate progesterone concentrations. The pregnancy rates were 40.47%, 37.50%, 44.44%, and 30.95% in Group 1, 2, 3, and 4, respectively (P > 0.05). In addition, in cows with progesterone concentrations <2 ng/ml on day 3.5, the pregnancy rates were found to be lower than in the cows with progesterone concentrations >2 ng/ml in Group 4 (P < 0.05). Progesterone supplementation in cows with progesterone concentrations < 2 ng/ml appeared to increase pregnancy rates (P < 0.05) in Groups 1 and 3. As a result, post-insemination hormonal applications in the repeat breeder cows did not increase the pregnancy rate. However, it was concluded that determination of progesterone concentrations on day 3.5 following artificial insemination and then hormonal support in the cows with low concentrations would increased the pregnancy rate.


Author(s):  
Jorge Alonso Peralta-Torres ◽  
Jesús Ricardo Aké-López ◽  
Carlos Luna-Palomera ◽  
José Candelario Segura-Correa ◽  
Oswaldo Margarito Torres-Chablé ◽  
...  

Evaluation of the reproductive tract development (RTD) is a criterion rarely used when heifers are included in estrous synchronization programs. The objective of the present study was to determine the effect of RTD (mature and immature) and hormonal treatment (EC and EB) on estrous expression rate and pregnancy rate in Bos indicus heifers under tropical conditions. RTD was evaluated with an ultrasound and classified as mature (n=99) or immature (n=101). Heifers received an intravaginal device (DIB®; day 0), 2 mg of estradiol benzoate (EB) and 250 µg of cloprostenol (PGF2α). The DIB was removed on day 7 post insertion, and 250 µg of PGF2α was applied and heifers were divided into two groups: One group of heifers received 0.5 mg of estradiol cypionate (EC group), and on day 8, a second group of heifers received 1 mg of estradiol benzoate (EB group). Estrus was detected by visual observation, and all heifers were inseminated at a fixed-time (FTAI). Fifteen days after insemination, bulls were introduced to the treatment groups. Data were analyzed using general modeling and binary logistic regression procedures. The percentage of estrus was similar for both mature and immature heifers (P>0.05), however, the heifers treated with EB had 17% animals in estrus, than the heifers that received EC (P <0.05). The pregnancy rate after FTAI (74.8%) and total pregnancy (FTAI + natural mating = 91.9%) was greater for the group of heifers with a mature reproductive tract (P<0.05). The hormone treatment had not effect (P>0.05) on the pregnancy rate. In conclusion, the heifers with mature reproductive tracts had the highest pregnancy rate after artificial insemination and total pregnancy. Hormonal treatment did not influence the pregnancy rate.


2019 ◽  
Vol 7 (2) ◽  
pp. 248-256
Author(s):  
Navaraj Chapagain ◽  
Bhuminandan Devkota ◽  
Gokarna Gautam ◽  
Shyam Kishor Sah ◽  
Dinesh Bhattarai

This study was designed to determine the effects of age, parity, feeding practice, Body Condition Score (BCS), blood nutritional parameters, types of anoestrus, and length of anoestrus on pregnancy rate of anoestrus buffaloes after their treatment with ovsynch protocol followed by fixed time artificial insemination. Blood samples were collected on the day ovsynch protocol and analyzed. The mean values of the nutritional parameters between different groups were compared by Students t test and pregnancy rate was compared by Fisher’s exact test or Chi-square test. The overall pregnancy rate in buffaloes was 28.6%, when checked on day 41 and 64.3% on day 102 of FTAI. Blood glucose, cholesterol, calcium and phosphorus level was found to be significantly higher (p<0.05) in pregnant than in non-pregnant buffaloes. Pregnancy rate was higher in silent estrus buffaloes. Buffaloes with BCS ≥3 had higher pregnancy rate than those with BCS < 3. Similarly, pregnancy rate was higher in lactating than in non-lactating buffaloes. While young buffaloes of age <10 year responded better than old buffaloes of age ≥10 year. Buffaloes which were free from gastrointestinal parasitic infection had higher pregnancy rate. In conclusion, ovsynch protocol produces a good pregnancy in anoestrus buffaloes; however, state of true anoestrus, older age and poor BCS with poor nutritional management adversely affect the pregnancy outcome. The role of blood nutritional parameters requires further clarification. Int. J. Appl. Sci. Biotechnol. Vol 7(2): 248-256  


2007 ◽  
Vol 19 (1) ◽  
pp. 154
Author(s):  
J. K. Park ◽  
S. Y. Jung ◽  
S. H. Park ◽  
A. N. Ha ◽  
J. I. Jin ◽  
...  

Nuclear transfer (NT) is one of the most advanced technologies to increase animal efficiency in livestock production. Re-cloning can be utilized to investigate more effective methods for agricultural, biological, and medical research. However, few studies have been undertaken on re-cloning from cloned animals. The present study was conducted to examine some factors affecting in vitro development of re-cloned embryos and pregnancy by somatic cell nuclear transfer (SCNT). Ear fibroblast cells as karyoplast donors were isolated from a cloned Korean goat, Jinsoonny, 3 weeks after birth and cultured in serum-starvation condition (TCM-199 + 0.5% FBS) for cell confluence. Recipient oocytes were surgically collected by flushing the oviducts at 35 h after hCG injection from FSH-stimulated goats. The zonae pellucidae of the oocytes were partially drilled using a laser system and each somatic cell was individually transferred into an enucleated oocyte. The couplets were electrically fused and activated by ionomycin (5 min) and 6-DMAP (4 h). The reconstructed embryos were cultured in mSOF medium containing 0.8% BSA at 39�C in an atmosphere of 5% CO2, 5% O2, 90% N2 for 12 to 15 h. Re-cloned embryos (2- to 4-cell stages) were surgically transferred into the oviducts of the recipients. Estrous synchronization was induced by 10 days of treatment with a CIDR and a single injection of PGF2�. Pregnancy was diagnosed by progesterone assay and ultrasound on Days 21 and 63 of pregnancy. The fusion and cleavage rates of re-cloned oocytes were 87.5% (182/208) and 56.0% (102/182), respectively. A total of 175 re-cloned embryos were transferred into 28 recipients. Eleven (39.3%) and 4 recipients (14.3%) were confirmed pregnant on Days 21 and 60, respectively. In comparison of pregnany rate by estrous synchronization, a total of 66 and 109 re-cloned embryos were transferred into 11 recipients in natural estrus and 17 recipients in induced estrus, respectively. Five (45.4%) and 2 recipients (18.2%) in natural estrus were confirmed pregnant on Days 21 and 63, while 6 (35.3%) and 2 (11.8%) recipients in induced estrus were pregnant, respectively. There were no differences in pregnancy rate when the recipients were in estrus within 12 h of the donors (40 to 60%). However, the pregnancy rate was significantly decreased when the difference was greater than 24 h (0 to 35%; P &lt;&lt; 0.05). Re-cloning can be used for many purposes, and synchronization between donors and recipients may be an important factor for further success of nuclear transfer.


2013 ◽  
Vol 25 (3) ◽  
pp. 581 ◽  
Author(s):  
Miguel Mellado ◽  
Claudia G. Orta ◽  
Eloy A. Lozano ◽  
Jose E. García ◽  
Francisco G. Veliz ◽  
...  

The objectives of this study were to examine the effects of several factors affecting fawning rate, litter size, litter weight and neonatal fawn mortality in white-tailed deer inseminated either transcervically or by means of laparoscopy. Oestrus synchronisation with a controlled internal drug release (CIDR)-based protocol and fixed-time artificial insemination (FTAI) was conducted in 130 white-tailed deer (Odocoileus virginianus texanus) during three reproductive seasons (2007–2009; 271 services) in a game-hunting ranch in a hot–arid environment (26°4′ N, 101°25′ W). Ninety additional non-treated does were exposed to bucks for natural mating. Fawning rate did not differ between AI methods (40.0 vs 45.0% for transcervical and laparoscopic AI, respectively). Overall fawning rate (proportion of all does fawning after FTAI and a subsequent period of buck exposure) did not differ between transcervical (89.5%), laparoscopic (80.3%) or natural (88.9%) insemination. Litter size per fawning doe was higher (P&lt;0.05) in naturally-served does (1.65±0.48) than in transcervically-inseminated does (1.40±0.51) or in laparoscopically-inseminated does (1.48±0.50). The main conclusion was that no enhancement of fawning rate or litter size occurred as a result of intrauterine deposition of semen by laparoscopy compared with the transcervical insemination technique.


2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 43-44
Author(s):  
Anna L Smith ◽  
Rebecca K Poole ◽  
Kyle Mayberry ◽  
McKayla A Newsome ◽  
Harrison B Dudley ◽  
...  

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.


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