scholarly journals 329PREGNANCY RATE IN EWES INSEMINATED WITH SEXED SEMEN IN ARGENTINA

2004 ◽  
Vol 16 (2) ◽  
pp. 284 ◽  
Author(s):  
L. Cattaneo ◽  
P. Martín ◽  
J.O. Caballero ◽  
M. Calvi ◽  
B. Vietri ◽  
...  

Offspring of many species have been born from flow cytometrically sex-sorted sperm since its introduction in 1989 (LA Jonhson et al.; 1999, Theriogenology). Births of lambs after insemination of ewes with low doses of sexed semen were first reported by Hollinshead et al. (Rep. Fert. Dev. 2002). A field trial was carried out in Patagonia Argentina comparing the use of low doses of sexed and non-sexed frozen semen. This study is aimed at comparing pregnancy rates in ewes inseminated with sorted and nonsorted frozen-thawed sperm. Ejaculates from two Merino rams were diluted with modified tirode solution (Shenk et al., 1999, Theriogenology), stained with Hoescht 33342, and finally incubated at 35°C for 40 minutes. The addition of 10% ram seminal plasma to the sample was done to avoid sperm agglutination caused by dilution effect (Mann, 1964). Sorting was performed with a high speed flow cytometer (MOFLO®). Up to 8 million of sexed spermatozoa were collected in 15-mL conical tubes containing modified tirode solution plus 10% ram seminal plasma, centrifuged at 600g 12min and resuspended with test yolk media plus 11% skimmed milk and 5% glycerol. After being refrigerated at 4°C for at least 1.5h, sexed and nonsexed semen were packaged in 0.25-mL straws at a concentration of 4 to 5 total million sperm and then frozen in an automatic freezing machine (IMV®). One hundred and eighty-three ewes and hoggets were laparoscopically inseminated by the same technician with eight to ten million sorted and nonsorted frozen-thawed semen 14h after heat detection. Pregnancy diagnosis was performed by ultrasound at day 30 post-insemination. Data were analized by Chi-square. There was significant difference in the overall pregnancy rate between sorted and nonsorted sperm, although, for one of the rams that difference was not significant. There was, also, no significant difference in pregnancy rate between ram 1 and 2 in ewes inseminated with either sexed or nonsexed semen (Table 1). These results indicate that the different performance of sorted compared to non sorted sperm is mainly explained by the lower results achieved with semen from ram 2. According to this conclusion, further studies should be done in order to evaluate the degree to which the sorting process affects the sperm fertilizing capability in different rams. This research was supported by Fundación Margarita Perez Companc. Table 1

2005 ◽  
Vol 17 (2) ◽  
pp. 303
Author(s):  
L. Cattaneo ◽  
A. Galassi ◽  
R. Franco ◽  
A. Duarte ◽  
K. Mello ◽  
...  

The only method of sexing sperm that works in any practical sense is measuring DNA content of individual sperm by flow cytometry, and sorting them based on that information (Schenk and Seidel 2002 J. Anim. Sci. 80 (Suppl. 1), 188). This is, also, the first reference of the use of sexed semen in Brazil. The objective of this experiment was to compare the fertility of sexed and non-sexed conventional semen in Bos indicus purebreeds. Ejaculates from eight Nelore bulls were collected by artificial vagina, diluted, and stained with Hoeschst 33342 (Schenk et al. 1999 Theriogenology 52, 1375–1391). A high-speed flow cytometer (SX-MOFLO®, DakoCytomation, Inc., Fort Collins, CO, USA) was used for sorting X sperm. Sexed semen was then packaged at 3 million total sperm in 0.25-mL straws and frozen. The average estimated purity obtained by resort analysis of one straw per batch was 91.5%. An aliquot of each ejaculate was frozen unsexed at a concentration of 50 × 106 sperm/mL in 0.5-mL straws (control). A total of 283 Nelore heifers were synchronized with two doses of PGF2α 12 days apart and inseminated in the body of the uterus 12 h after heat detection. Field trials were carried out in four different states in Brazil: Minas Gerais (MG), Mato Grosso (MT), Mato grosso do Sul (MS), Rondônia (RO). Pregnancy diagnosis and fetal sex determination were performed by ultrasound 30 and 60 days post-AI, respectively. Data were analyzed by chi-square and Monte Carlo methods. There was no significant difference (P < 0.05) in pregnancy rate between sexed and non-sexed semen (see Table 1). At the time of abstract submission, of 41 pregnant heifers from sexed semen confirmed by ultrasound, 40 had a female fetus (97%). These results indicate that sexing semen by flow cytometry could be a very important tool to accelerate the genetic gain in Bos indicus cattle. Brazil has the largest commercial herd in the world and, therefore, a great potential to incorporate this technology that is now available in the country. Table 1.


2015 ◽  
Vol 27 (1) ◽  
pp. 126
Author(s):  
H. S. Martins ◽  
M. F. Brito ◽  
I. B. M. Sampaio ◽  
R. Stahlberg ◽  
M. R. Souza ◽  
...  

During cryopreservation, the sperm were submitted to an increased generation of reactive oxygen species. Furthermore, because of the large portion of seminal plasma removal, there is a decrease of sperm antioxidant protection. Addition of antioxidants proteins found in seminal plasma, such as lactoferrin (Lf) and catalase (Cat), to the freezing semen extenders could protect the sperm during cryopreservation. Lactoferrin is a transferrin, which prevents the hydroxyl radicals generation, and Cat plays an antioxidant role. The aim of this study was to determine the effects of Lf and Cat supplementation to the INRA 82 freezing extender (Battelier et al. 1997) on sperm motility parameters and membrane functionality of stallion frozen semen. Semen from 6 stallions was collected with an artificial vagina, diluted with Kenney extender (1 : 1), and centrifuged (500 × g, 10 min). The supernatant was discarded, and sperm number per milliliter was calculated. Semen was resuspended with 3 extenders to 100 × 106 sperm mL–1. The treatments were distributed in (F1) control, INRA 82 freezing extender (Battelier et al. 1997), (F2) F1+ 500 μg mL–1 lactoferrin, and F3) F1 + 200 IU mL–1 catalase. Semen samples were packaged in 0.5-mL straws and cooled to 5°C (0.27°C min–1). For semen freezing, the straws were laid over the LN vapor for 20 min and plunged into the LN. The straws were thawed at 37°C for 30 s. Motility parameters of frozen semen were determined using a computer sperm cell analysis, and sperm membrane functionality was assessed by the hyposmotic swelling test (Lagares et al. 1998). The data were analysed using Friedman test using stallion as a block. A probability of P < 0.05 was considered significant. There was no significant difference between the percentage of total sperm motility (median, minimum-maximum value; F1: 29.9, 11.0–82.7; F2: 49.8, 7.7–55.2; F3: 39.8, 5.7–92) and progressive sperm motility (F1: 7.1, 3.2–23.3; F2: 13.4, 2.6-22.4; F3: 15.6, 1.1–29.6), and functional sperm membrane (F1: 26.7, 14.7–56.2; F2: 50.5, 15.7–61.7; F3: 46.6, 13.8–50.9) with regard to the treatment. However, the velocity parameters: velocity average path (F1: 29.3, 22.1–33.80; F2: 34.6, 24.8–44; F3: 35.7, 18.2–42.6), velocity curvilinear (F1: 36.9, 30.5–45.1; F2: 42.5, 34.7–51; F3: 44.6, 25.5–50.9), and velocity straight line (F1: 23.4, 17–3.60; F2: 28.9, 18.8–38.2; F3: 26.6, 13.6–37.2) in the treatment with Lf (F2) were higher compared with the control (F1; P < 0.05). These results corroborate with studies reporting the lack of positive effect on equine sperm motility when antioxidants were added to skim milk-based extenders. Although the addition of Lf or Cat to skim milk-based extenders did not improve the motility sperm characteristics and sperm membrane functionality, more studies about the positive effect of Lf on the velocity parameters are necessary. Lactoferrin could then play an important role on the oxidative metabolism, which provides energy to the sperm movement.Acknowledgments to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brazil, for the financial support.


2017 ◽  
Vol 29 (1) ◽  
pp. 119 ◽  
Author(s):  
A. Swelum ◽  
A. Moumen ◽  
A. Alowaimer

This study was carried out using 80 multiparous Awassi ewes during breeding season to compare the effects of controlled internal drug release (CIDR) withdrawal time on ewe fertility. Ewes were equally and randomly allotted into 4 groups (n = 20/group). Ewes had a CIDR inserted for 3, 6, 9, or 12 days with intramuscular administration of 300 IU of equine chorionic gonadotropin (eCG) at withdrawal time. Oestrus was detected using vasectomized ram starting 12 h after CIDR withdrawal and repeated every 12 h up to 84 h. Blood samples were collected from all groups at the time of CIDR withdrawal for measuring of oestradiol (E2) and progesterone (P4) serum concentrations using commercial ELISA kits and micro-titrimetric plates. Timed insemination was performed 48 h post CIDR withdrawal in all groups. Pregnancy was diagnosed by ultrasonography at day 23 post-insemination and confirmed at day 35. Comparisons among groups were evaluated using Chi Square (χ2) test in all measured parameters except hormones levels, which analysed by repeated-measures analysis of variance (ANOVA), using SAS (SAS Institute Inc., Cary, NC, USA). A difference was considered significant at P < 0.05 level. The results revealed that the retention, vaginal discharge and drawstring breakage rates after CIDR removal were insignificantly differed between all groups. On the other hand, pregnancy rate was significantly (P ≤ 0.05) higher in 9-d and 6-d groups (68.4 and 60%, respectively) than the 3-d group. While, no significant difference was detected between 12d group and other groups. The heat detection rate was significantly (P ≤ 0.05) higher in 12d group (100%) than 6-d and 3-d groups (80 and 45%, respectively). While, no significant difference was detected between 12-d and 9-d groups in heat detection rate. P4 was significantly higher in the 12-d group (13.4 ± 3.06 ng mL−1) than other groups. While E2 was significantly lower in the 12-d group (1.6 ± 0.06 pg mL−1) than other groups. These results indicated that withdrawal of CIDR devices after 9 days are efficient in synchronizing oestrus in ewes and provided higher pregnancy rate.


2007 ◽  
Vol 19 (1) ◽  
pp. 124 ◽  
Author(s):  
A. Heise ◽  
D. Gerber ◽  
D. H. Volkmann ◽  
W. Kähn ◽  
N. K. Brouwer

The aim of this study was to determine if the addition of equine seminal plasma to epididymal semen enhances its fertility before or after freezing. Thirty-two mares were randomly assigned to 5 stallions; 3 stallions were kept in Pretoria, each having 7 mares, and 2 stallions were kept at Cornell, one having 6 mares and the other 5. Mares were synchronized using 10 daily IM progesterone and estradiol injections; an Ovuplant® implant (26 mg of deslorelin; Peptech Animal Health, Sydney, NSW, Australia) was inserted under the mucosa of the vaginal vestibulum once a follicle reached a diameter of 35 mm; implants were removed after ovulation. Mares were inseminated 30 h after implant insertion. Each insemination dose consisted of 200 million progressively motile sperm and was deposited into the uterine body. Following insemination, mares were examined for ovulation at 6 hourly intervals. Fourteen days after ovulation, mares were examined for pregnancy by transrectal ultrasonography and treated with PGF2α to induce the next estrus. Seminal plasma was collected from the stallions used in the trial prior to castration, frozen, and stored. In Pretoria, stallions were castrated and one epididymal tail was flushed with seminal plasma and the other with skim milk extender; in the first cycle, half of the mares were inseminated with one of the two sperm samples. In Cornell, testes of each stallion were removed 3 weeks apart, and all mares were inseminated first with one and 3 weeks later with the other semen sample. Mares were inseminated during consecutive estrous cycles using the following sperm types: fresh epididymal sperm that had been exposed to seminal plasma (G1: 4 mares per stallion in Pretoria, 6 and 5 mares per stallion at Cornell); fresh epididymal sperm that had never been exposed to seminal plasma (G2: 3 mares per stallion in Pretoria, 6 and 5 mares per stallion at Cornell); frozen–thawed ejaculated sperm (G3); frozen–thawed epididymal sperm that had been exposed to seminal plasma prior to freezing (G4); and frozen–thawed epididymal sperm that had never been exposed to seminal plasma (G5). The results of inseminations with fresh epididymal semen (G1–2) of 5 stallions and the preliminary results of inseminations with frozen–thawed epididymal semen (G3–5) of 2 stallions are summarized in the Table 1. Cycles where ovulation did not occur within 12 h after insemination were excluded. The pregnancy rate of mares inseminated with fresh epididymal sperm of G1 was significantly higher (chi-square test; P &lt; 0.05) than that of mares of G2. The pregnancy rate of mares inseminated with frozen–thawed ejaculated semen (G3) was similar to that of mares inseminated with frozen–thawed epididymal semen of G4 and G5 (P = 0.3). Based on these preliminary results, we conclude that the fertility of fresh epididymal sperm can be enhanced by exposure to equine seminal plasma. To determine if the same holds true for frozen–thawed epididymal sperm, more inseminations must be performed. Table 1.Results of inseminations with various semen types


2013 ◽  
Vol 25 (1) ◽  
pp. 151
Author(s):  
A. Niasari-Naslaji ◽  
V. Akbarinejad ◽  
K. Hoseinipajooh ◽  
G. Akbari ◽  
S. Gharibi ◽  
...  

The present study was conducted to evaluate laparoscopic intrauterine and intraperitoneal AI in a fat-tailed sheep breed. Multiparous and nulliparous (n = 72) healthy Shall ewes (Iranian native breed) were assigned into 3 experimental groups to be inseminated with 3 laparoscopically insemination methods, including intrauterine insemination with frozen semen (IUIFZ; n = 34), intraperitoneal insemination with fresh semen (IPIFR; n = 21), and intraperitoneal insemination with frozen semen (IPIFZ; n = 17). To perform the experiment easily and control confounding factors, the experiment was conducted in 5 replicates. In each replicate, similar numbers of ewes belonging to each experimental group were included, synchronized, and inseminated with the fresh or frozen semen collected from the same fertile ram. Estrus was synchronized using CIDR for 14 days. Immediately after CIDR removal, all ewes received 400 IU of pregnant mare serum gonadotropin. Inseminations with 300 million total spermatozoa (≥70% progressive forward motility) were performed 51.1 ± 0.64 h after CIDR removal. Intrauterine insemination was conducted at the tip of the uterine horn, ipsilateral to the ovary having a dominant follicle. In the case that both ovaries had a dominant follicle, half of the straw was deposited in each horn. In 2 other experimental groups (IPIF and IPIR) either fresh or frozen semen was deposited on the surface of ovaries having a dominant follicle. Pregnancy was diagnosed with transrectal ultrasonography on Day 30 after AI. Data were analyzed using logistic regression. The pregnancy rate in the IUIFZ group (51.7%) was significantly higher than in IPIFR and IPIFZ experimental groups (17.6 and 0%, respectively; P < 0.01), and there was significant difference between IPIFR and IPIFZ in pregnancy rate (P < 0.05). In conclusion, the laparoscopic intrauterine insemination method can be applied effectively in Shall fat-tailed sheep. Laparoscopic intraperitoneal inseminations with fresh or with frozen semen are not recommended for AI in fat-tailed sheep.


2011 ◽  
Vol 23 (1) ◽  
pp. 116
Author(s):  
Y. S. Park ◽  
Y. G. Cho ◽  
K. H. Cho ◽  
G. J. Cho

Research in the area of equine artificial insemination (AI) has led to its increased application in field trials (Loomis and Graham, 2008). However, procedures for equine semen collection, cooling and freezing of semen and artificial insemination need further improvement. This study examined the effect of semen preparation and ovulation on equine AI success. Stallion semen was collected via artificial vagina, diluted with skim-milk extender, and preserved by either cooling to 4°C or cryopreservation and storage in liquid nitrogen. Mares were examined by ultrasound for follicle development with every 12 h during oestrus. During AI, semen was inserted into uterine horn adjacent to the ovulating follicle sized over 4 cm and irregular shape. In experiment 1, mares were inseminated with either cooled, cooled-transported, or frozen–thawed semen. Cooled semen was used immediately after collection and cooling. Cooled-transported semen was used 4 h after semen collection and dilution. Semen freezing procedure was followed by Moore et al. (2006). In experiment 2, we examined the effect of buffer (skim-milk extender), which was infused into the uterus at the time of AI with frozen–thawed semen. In experiment 3, we compared AI pregnancy rates for mares ovulating spontaneously v. after treatment with hCG. Pregnancy data were analysed Chi square test where P-values < 0.05 were considered significantly different. In experiment 1, the pregnancy rates after AI using cooled, cooled-transported, and frozen–thawed semen were 60 (10/6), 50 (8/4), and 37.5% (8/3), respectively, and similar among treatments. In experiment 2, the pregnancy rate of mares infused with buffer at AI was 37.5% (8/3) which was higher than that with no buffer (0%; 6/0). In experiment 3, the pregnancy rates of mares were similar between ovulated spontaneously (25%; 8/2) and ovulated with hCG (50%; 8/4). The results suggest that equine semen that has been cooled, cooled and transported or frozen can be successfully used to establish AI pregnancy. Also, the pregnancy rates after AI can be increased by infusing buffer into the uterus at AI or by inducing ovulation with hCG. These experiments resulted in the first foal produced in Korea with frozen–thawed equine semen. This research was supported by Technology Development Program for Agriculture and Forestry, Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea.


2020 ◽  
Vol 32 (2) ◽  
pp. 204
Author(s):  
M. Yamaguchi ◽  
M. Takayama ◽  
T. Nishisouzu ◽  
H. López ◽  
O. Dochi

Compared with conventional semen, use of sexed semen decreases the conception rate (CR); therefore, it is important to address the factors that lead to sperm damage. Recently, a novel sexed semen technology was developed for improving dairy cattle fertility (Betthauser et al. 2016 J. Dairy Sci. 99 (E-Suppl. 1), 534). However, there are few reports about the fertility of this novel sexed semen in dairy cattle in Japan. The objective of this study was to compare the CR of traditional sorting semen (S1: flow cytometry/cell sorting) and the novel sexed semen (S2: SexcelTM, ABS Global Inc.) in Holstein heifers and cows in Japan. The CR for the first insemination was obtained from 391 Holstein cows and 148 heifers (10.7-17.8 months old) from 14 dairy farms in Hokkaido from June 2017 to April 2019. Semen used for AI was collected from six bulls and packaged into 0.25-mL straws and frozen. Cows inseminated with conventional frozen semen (S3: unsexed semen in 0.5-mL straws) were used as controls. Calving data were collected from 123 cows and 69 heifers that had calved between January 2018 and May 2019. The diagnosis of pregnancy was confirmed using ultrasonography between 30 and 45 days after insemination. The CR and sex ratio were analysed using chi-square test. The average parity number was 1.9±1.1, and average days open was 84.9±20.4 days. The average interval between calving and the first service was 86.2±20.3 days. The average milk yield (at 305 days) was 12 195±1595 kg. All of the animals were inseminated after the onset of standing heat or removal of the tail chalk of natural heats and oestrus and ovulation synchronisation programmes on the farm. Conception rates of heifers of the first service of S1 (n=54) and S2 (n=94) were 68.5 and 70.2%, respectively. Conception rates of cows of the first service of S1 (n=32), S2 (n=173), and S3 (n=186) were 56.3, 57.8, and 53.8%, respectively. There were no significant differences in CR between these groups (P&gt;0.4). The proportion of female calves produced using S1 (n=61) and S2 (n=57) was 91.8 and 93.0%, respectively, which was significantly more (P&lt;0.01) compared with the 50.0% produced using S3 (n=74). There were no significant differences between S1 and S2 (P&gt;0.8) in terms of the proportion of calves produced. The results of this study demonstrated that the traditional sorting and novel sexed semen (S1 and S2, respectively) did not differ in terms of the first-service CR and produced considerably more female calves than when the conventional semen (S3) was used. Furthermore, these findings indicate that the use of this novel sexed semen could achieve a sex ratio close to 90% female offspring.


2019 ◽  
Vol 31 (1) ◽  
pp. 175
Author(s):  
R. Cuya ◽  
W. Huanca ◽  
G. Medina ◽  
R. Sanchez ◽  
W. F. Huanca

Alpacas, similar to other camelids, are classified as induced ovulators, as an external stimulus is required for the occurrence of ovulation. A protein identified as β-nerve growth factor, present in the seminal plasma (SP), has the capacity to induce ovulation and corpus luteum formation. Alpacas exhibit poor reproductive efficiency, with birth rates below 50% due in part to high embryo mortality before 35 days post-mating. A study was carried out to evaluate the effect of the application of SP on Day 0, 5, or 7 post-mating on pregnancy rate and embryo survival, defined as the difference in the numbers of pregnant females between Day 35 and 25. Nonpregnant adult alpaca females (n=124) between 5 to 6 years old were evaluated by transrectal ultrasonography to determine presence of a follicle ≥7mm, and then 2 days later to confirm permanence of the follicle. Alpacas were then bred by natural mating and assigned randomly to 1 of 4 treatments: 1mL of SP IM at mating; 1mL of SP IM Day 5 post-mating; 1mL of SP IM Day 7 post-mating; and control. Semen was collected from adults male and ejaculates were diluted 1:1 with PBS and then centrifuged for 30min at 3000 rpm. Supernatant was separated and a drop evaluated to determine absence of spermatozoa and SP-free sperm was stored at −20°C. Twenty adult males with optimal reproductive performance were used for mating with females assigned to the different treatments. Animals were evaluated by ultrasound with an Aloka SSD 500 (Aloka, Tokyo, Japan) and 5.0-MHz linear transducer on Day 25 and 35 to determine pregnancy rate and embryonic survival. Data were analysed by chi-square. Results are present in Table 1. The results differ from our initial hypothesis and a possible explanations may be that additional application of SP IM could saturate receptors and block the action of the seminal plasma present in the ejaculate of males. Table 1.Pregnancy rate and embryonic survival in alpacas with application of seminal plasma on Day 0, 5, or 7 Study was supported by project no. 405-PNICP-PIAP-UNMSM.


2004 ◽  
Vol 16 (2) ◽  
pp. 127 ◽  
Author(s):  
G. Brogliatti ◽  
G. Barreiro ◽  
G. Larraburu ◽  
A. Laborde

Flow citometry cell sorting has been proven successfully to separate X and Y sperm; however, the technology is still too stressfull for the viability of the sorted semen. The objective of this study was to evaluate nonsexed and sexed frozen sperm motility characteristics using a CASA technology. Ejaculates from 4 different bulls (3 Holstein and 1 Angus) were collected, and processed as split non-sexed and sexed semen samples using Tris egg yolk extenders. X and Y sperm were separated using a high-speed sorter (SX Moflo). Cryopreservation was done at the same time under appropiate conditions using a programmed cryochamber. Thawing procedure was done at 37°C for 30s and a sample of each straw was placed in the evaluation chamber. The experiment was repeated twice and two chambers with 30 observations each were analyzed each time. Mean and standard deviation of each characteristic were calculated, compared and analyzed statistically. The sperm concentration was determined by means of a burker counting chamber. Sperm quality was determined at 0h after thawing, and later at 1h, 2h and 3h after incubation in a glass tube at 30°C. The following sperm motility parameters were determined with the Hamilton Thorne (HTM-ceros 12.1) on at least 1000 spermatozoa: velocity average path (VAP), velocity straight line (VSL), amplitude lateral head (ALH), beat cross frequency (BCF), straightness (STR), linearity (LIN), and percentage of progressively motile spermatozoa (PMS). Linearity of nonsexed spermatozoa was 53±3.5, 47±0.8, 43±7.8 and 42±4.5 for the 0h and the 3 test incubation times and 49.5±3.7, 51.2±3.7, 43.3±7.8 and 44.5±7.6, respectively, for sexed semen. There were no significant differences (P&gt;0.05) in the progressive velocity, track speed and linearity between sexed and nonsexed semen. The percentage of static cells was 33%, 30%, 47% and 50% for the 0h and the 3 test incubation periods; however, the percentage of static cells for the sexed semen was 53%, 71%, 77% and 82%, respectively. Results from the analysis indicate a significant increase (P&lt;0.01) in the number and the percentage of static cells with time. The lateral amplitude of sperm motility for nonsexed semen was 5.9±0.5, 6.8±0.8, 6.0±0.4 and 5.1±0.7, and for sexed semen 6.6±0.7, 6.8±0.4, 6.4±0.4 and 5.5±1.7, respectively. The percentage of progressively motile sperm was significantly different at 0 time 49.7±4.9 and 23.1±4.9 for nonsexed and sexed semen respectively. After 3 hours of incubation the percentage of progressively motile sperm was 38.7±10.2 and 3.7±3.2 for nonsexed and sexed semen, respectively. In conclusion, sexed frozen semen seems to have characteristics similar to those of normal nonsexed semen. However, a significant decrease in the percentage of progressively motile cells could affect pregnancy rates. More research needs to be done to detect differences between bulls and cryoprotectans.Research supported by Centro Genetico Bovino de EOLIA sa Argentina.


2019 ◽  
Vol 17 (1) ◽  
Author(s):  
M. J. S. Bhuiyan ◽  
M. T. Islam ◽  
N. S. Juyena ◽  
M. M. U. Bhuiyan

Background: To mitigate the increasing protein demand in Bangladesh, recently the government has started a program to inspire the farmers for rearing Brahman as a beef breed. But, it is necessary to assess the performance of frozen semen of Brahman bull and the other factors that affect the rate of conception after Artificial Insemination (AI) before widespread rearing in Bangladesh. Methods: Data on AI performance, different factors and rate of conception were collected from 150 inseminated cows and heifers of Sadar upazila, Mymensingh. The cows were inseminated by trained technician of Research Animal Farm of Department of Surgery and Obstetrics, BAU, Mymensingh. Results: The overall conception rate was 55.3%. The conception rate in Holstein Friesian cross (68.9%) and Sahiwal cross (66.7%) cows were relatively higher than that of Local (46%) cows. Upon increasing age the service required for conception was irregular. The conception rate with respect to different parities ranged from 47.0% to 58.7%. Cows received insemination at parity 1-2 showed highest conception rate (60.0%) and cows received insemination at parity 3-7 showed lowest conception rate (47.0%). There was no significant difference between them on conception rate. The conception rate was observed higher (69.2%) in the cows which were inseminated in spring than cows were inseminated in summer (57.3%), winter (53.3%) and rainy (38.5%). The pregnancy rate in cows having BCS 2.5-3 was higher (60.7%) than that of 2.0 and 3.5-4.0. However, the difference in conception rate did not vary significantly among different BCS of cows (p>0.05). The present study indicated that the pregnancy rate in cows was higher (76.9%) that yield 6-10 L of milk than those of 0, 1-2 and 3-5 L counterpart. However, the variation in conception rate with different milk yield was significant (p<0.05). The pregnancy rate in cows that inseminated between 19-24 hours was higher (66.0%) than that of ≤12 and 13-18 hours. The variation in conception rate with different interval between estrus to AI was significant (P<0.05). Conclusion: Further studies using more population of cows and semen donors are needed to confirm this result as low number of cows and only one semen donor were used in this study.


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