Semen Artificial Insemination Research Articles

Lipidomic profiling of cervical mucus reveals the potential role of pro-inflammatory derived metabolites on sperm transport across the ovine cervix

Internationally, cervical artificial insemination (AI) in sheep yields low pregnancy rates when frozen-thawed semen is used. An exception to this is in Norway where vaginal AI of frozen-thawed semen to a natural oestrus yields non-return rates in excess of 60%, which has been attributed to the ewe breed used in Norway. This study used both metabolomics and an RNA-sequencing approach to assess the lipid production and composition from cervical mucus and tissue of four European ewe breeds (n = 28–30 ewes per breed) with previously reported differences in pregnancy rates following cervical AI with frozen-thawed semen. These breeds included Suffolk (exhibiting low fertility), Belclare (medium fertility) as well as Norwegian White Sheep and Fur (both with high fertility and pregnancy rates > 60%) at both a synchronised and natural oestrous cycle. The aim was to explore the differences between ewe breeds in the lipidomic profile and to identify candidate biomarkers associated with an optimal environment for cervical sperm transport. The results revealed the identification of 255 lipids, of which 170, 102 and 83 were different between ewe breeds, types of cycle and affected by their interaction, respectively (P < 0.05). Reduced levels of lipids involved in the resolution of inflammation (i.e. 14-HDoHE,17-HDoHE, 15-HETE) were identified in the low-fertility Suffolk breed compared to high-fertility ewe breeds. However, there was an up-regulation of the COX pathway accompanied by increased levels of prostaglandins in the Suffolk breed. These findings indicated a sub-optimal and pro-inflammatory environment that could have a negative effect on cervical sperm transport.

Failure of isoxsuprine HCl to increase sheep fertility after cervical versus laparoscopic AI using chilled semen at different durations

To improve the fertility of cervical artificial insemination (AI) in sheep, we investigated isoxsuprine HCl usage on the cervical passage during cervical AI. We also compared cervical and laparoscopic AI fertility results of using chilled semen at different durations. Semen was collected from rams and diluted as 20 × 106 or 400 × 106 spermatozoa/straw for laparoscopic and cervical AI, respectively, and chilled to 4°C within 2 h. Sheep were inseminated with chilled semen for 8 or 24 h via the laparoscopic or cervical AI method. Moreover, some of the cervical inseminated sheep were injected intramuscularly with 0.5 mg/kg of isoxsuprine HCl 15 min before AI. As a result, the use of isoxsuprine HCl did not affect cervical transit and fertility. In addition, fertility was affected by the storage duration of the semen; laparoscopic AI was more successful than cervical AI in terms of fertility; if cervical AI is performed, the duration between semen collection and AI should be less than 8 h after chilling the semen at 4°C, and if laparoscopic AI is performed, the time between semen collection and insemination can be up to 24 h after chilling the semen at 4°C. Longer storage periods should be studied.

PSIII-7 Effect of Time of Estrus on Conception Rate for a Sexed Semen Artificial Insemination Protocol in Multiparous Beef Cows

Abstract Sexed semen artificial insemination is a breeding technique that allows producers to shorten breeding seasons, optimize genetics through use of superior semen, create calves based on sex preference, and increase profitability. Sexed semen is a technology that sorts semen by differences in DNA content between X (female) and Y (male) bearing sperm. However, sexed semen practices have yet to be widely used in beef cows due to reduced sperm numbers, low conception rates, and increased costs. The objective of this study was to determine the effect of time of estrus upon fixed-time artificial insemination (FTAI) of sex-sorted semen on conception rate using two different estrous synchronization protocols. Multiparous commercial beef cows (n = 73) were randomized by age, body condition score (BCS), and days post-partum at the University of Arkansas Livestock and Forestry Research Station in Batesville. Both synchronization treatments (TRT) used a controlled internal drug releasing device (Eazi-breed CIDR; 1.38g progesterone) inserted intravaginally on d -14 of the protocol simultaneous to administration of prostaglandin F2α (PGF; 500µg cloprostenol sodium; Estrumate). In the first treatment (TRT 1; 7&amp;7 Synch), gonadotropin-releasing hormone (GnRH; 86µg gonadorelin; Fertagyl) was administered on d -7. In the second treatment (TRT 2; 8&amp;6 Synch), GnRH was administered on d -6. Both treatments were then administered PGF simultaneous to CIDR removal on d 0, 66 ± 2h before FTAI and administration of GnRH. Standing heat (estrus) was visually detected every 3 h for 30 min intervals between CIDR removal and FTAI. Heat detection patches were used in conjunction with visual detection of estrus. Time of estrus was signified as time of standing immobile when mounted in combination with presenting a patch score of 4 (&amp;gt;75% color removed). Time of estrus (TD) was deviated from time of FTAI and categorized into three equal time groups (Grp 1 = 0 to 11.0 h; Grp 2 = 11.01 to 22.0 h; and Grp 3 = 22.01 to 33.0 h). Conception rate (CR) was determined via ultrasound 37 ± 2 d after FTAI. Data were analyzed using the GLIMMIX procedure of SAS 9.4. CR did not differ by age of dam (P = 0.58), BCS (P = 0.48), or TRT (P = 0.83). However, TD had an effect on CR (P = 0.002); and resulted in CR of 45% (Grp 1), 87% (Grp 2), and 42% (Grp 3). In conclusion, these results indicate artificially inseminating cows with sexed semen between 11.01 and 22.0 h after time of standing estrus will increase pregnancy rates for multiparous commercial beef cattle.

Reproductive performance of Jamunapari crossbred using frozen semen

Artificial insemination (AI) is modern techniques to introduce better and new genetic at the small holder farmer level by using frozen for livestock development. The aimed of the present study to popularization of goat’s artificial insemination to increase goat production with improved genetic merit by assessing the productive and reproductive traits using Jamunapari frozen semen. The study has been conducted in ten upazila namely Paba, Bagha, Nachal, Chapai sador under Rajshahi region and Birampur, Parbotipur, Fulbari, Kaliganj, Ulipur, Kawnia upazilas under the Rangpur regions. Artificial insemination has been performed in 260 numbers of does. The semen samples initially qualified for freezing was frozen as per the protocol standardized in BRAC bull station, stored in liquid nitrogen (LN2) having the post thaw motility of 50% and were later used for AI. The service per conception was 1.10 in the present study. Moreover, we found that overall conception rate was 67.1%. The average birth weight of male and female kids was 0.98 and 0.95 kg, respectively. In the present study kidding produced single, twins and triplets in 37.7, 50.65 and 11.69% of cases, respectively. The average post-partum heat period was 76.5 days. The results indicated frozen semen AI could successfully be used for preservation, conservation and propagation in Jamunapari goats. Bangladesh Journal of Animal Science 52 (3): 85-87.

Mortality, growth, and egg production do not differ between nontransgenic and transgenic female chickens with ubiquitous expression of the 3D8 single chain variable fragment gene

To date, many transgenic (TG) chicken lines have been developed, but few studies have performed a comparative analysis of their mortality, growth, and egg productivity. Previously, we reported the production of 3D8 scFv TG chickens showing antiviral activity. Here, we performed a biometric characterization of TG offspring female chickens. We selected 40 TG and 40 non-TG offspring female chicks among newly hatched chicks produced via artificial insemination of semen from heterotypic 3D8 scFv males into wild-type female chickens. Serum was collected at 14 wk of age, and serum concentrations of biochemical parameters, cytokines, and sex hormones were analyzed. Mortality and growth were monitored daily from 1 to 34 wk, egg productivity was monitored daily from 20 to 34 wk, and the weekly average values were used for analyses. Some serum parameters and cytokines were significantly different between non-TG and TG offspring female chickens. The levels of phosphorus (PHOS), total protein (TP), albumin (ALB), globulin (GLOB), and alanine aminotransferase (ALT) were significantly higher in non-TG chickens (P < 0.05). The levels of alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT) were significantly higher in TG chickens (P < 0.05). The levels of insulin growth factor-1 (IGF-1), interferon-gamma (INF-γ), interleukin-4 (IL-4), and IL-8 were significantly lower in TG chickens (P < 0.05). Despite these differences, the mortality rates, body weight, egg production rates, and egg weight were not significantly different in the experimental groups of non-TG and TG offspring female chickens (P > 0.05). In conclusion, ubiquitous expression of the 3D8 scFv gene in TG offspring female chickens does not affect some biometric characteristics, including mortality, growth, and egg productivity.

Epigallocatechin-3-gallate chitosan nanoparticles in an extender improve the antioxidant capacity and post-thawed quality of Kacang goat semen

Background and Aim: The Kacang goat (Capra hircus) is an indigenous livestock species in Indonesia that is at risk of extinction due to cross-breeding. Artificial insemination (AI) techniques are expected to increase the population of these goats. This study aimed to determine the addition of epigallocatechin-3-gallate chitosan nanoparticles (EGCG CNPs) to skim milk–egg yolk (SM–EY) extender to obtain the best possible quality of post-thawed Kacang buck semen for AI. Materials and Methods: Fresh Kacang buck semen was diluted in SM–EY without or with the addition of 0.5, 1.0, 1.5, or 2.0 µg of EGCG CNPs/mL extender. Extended semen was packaged in French mini straws, frooze, and stored in liquid nitrogen at −196℃ for 24 hours. Six replicates from each treatment group were thawed for catalase, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, malondialdehyde (MDA), sperm intact plasma membrane (IPM), viability and motility analyses. Results: Post-thawed semen that was previously frozen without EGCG CNPs in the extender (control group) exhibited the lowest levels of catalase, DPPH, sperm living cells, sperm motility, MPI, and the highest levels of MDA. The addition of EGCG CNPs in the T3 and T4 groups was increased (p &lt; 0.05) post-thawed catalase, DPPH, living cells, and sperm motility and decreased (p &lt; 0.05) MDA levels than those of the T0 group. Meanwhile, sperm MPI was higher (p &lt; 0.05) in the T4 group than the sperm MPI of the T0 group. Conclusion: This study was the first in using of EGCG CNPs in the SM–EY extender, in which adding 1.5 or 2.0 μg/mL of EGCG CNPs in this extender increased the antioxidant capacity and post-thawed quality of Kacang buck semen.

Danish milk consumers are critical of advanced breeding methods in dairy production, but only 1 in 5 is unwilling to drink milk from dairy cows bred with semen derived from such methods

Assisted reproductive technologies and genetic technologies can accelerate progress in breeding programs in dairy farming, but it is unclear how consumers will react to the use of these technologies. Using representative questionnaire data on Danish citizens (n = 2,036) this cross-sectional study examined consumer attitudes to the application of advanced technologies in dairy cattle breeding. Attitudes were examined in 2 ways. First, we prompted about general attitudes to assisted reproductive technologies and genetic technologies in dairy cow breeding. Here we found that most of the participants were critical of cow impregnation involving hormone therapy and the insertion of cloned fetuses. Second, we used a vignette experiment to study whether acceptance of and willingness to drink milk varies with the type of technique that farmers use for their breeding work, as well as the traits being bred for. We included 5 breeding methods with differing degrees of technological complexity. Participants were randomly assigned to receive tailored information about 1 of the 5 breeding methods. The information specified that dairy farmers' own use of advanced technologies is limited to using semen in artificial insemination on the farm. The potentially concerning technologies are here not applied at farm level but are represented in the semen used in artificial insemination because they were used by breeders on earlier generations of cows and bulls to develop semen with higher genetic merit. There was much less concern about this indirect use of the technologies. Only 1 in 5 participants thought the most advanced method we prompted about (use of semen from breeding methods involving genetic engineering and cloning) was unacceptable. Unwillingness to drink milk from cows produced through such a breeding method was also modest (18%) and not much higher than the unwillingness to drink milk from a cow produced by natural fertilization (10%). A likely reason for the unexpectedly low level of unwillingness to drink milk is that people regard the genetic engineering as distant from the final product. We also found that high-frequency organic milk consumers were more critical of advanced breeding methods. Thus, 28% within this group were unwilling to drink milk from cows impregnated with semen derived from earlier generations of cows and bulls bred using gene editing and cloning. Further, this share rose if the high-frequency organic consumers were very averse to the manipulation of nature. The organic sector may need to cater to this subgroup (e.g., by ensuring the traceability of the semen that organic farmers use to artificially inseminate their cows).

Epigallocatechin-3-gallate chitosan nanoparticles in an extender improve the antioxidant capacity and post-thawed quality of Kacang goat semen

Background and Aim: The Kacang goat (Capra hircus) is an indigenous livestock species in Indonesia that is at risk of extinction due to cross-breeding. Artificial insemination (AI) techniques are expected to increase the population of these goats. This study aimed to determine the addition of epigallocatechin-3-gallate chitosan nanoparticles (EGCG CNPs) to skim milk–egg yolk (SM–EY) extender to obtain the best possible quality of post-thawed Kacang buck semen for AI. Materials and Methods: Fresh Kacang buck semen was diluted in SM–EY without or with the addition of 0.5, 1.0, 1.5, or 2.0 µg of EGCG CNPs/mL extender. Extended semen was packaged in French mini straws, frooze, and stored in liquid nitrogen at −196℃ for 24 hours. Six replicates from each treatment group were thawed for catalase, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, malondialdehyde (MDA), sperm intact plasma membrane (IPM), viability and motility analyses. Results: Post-thawed semen that was previously frozen without EGCG CNPs in the extender (control group) exhibited the lowest levels of catalase, DPPH, sperm viability, sperm motility, IPM, and the highest levels of MDA. However, the addition of EGCG CNPs at doses of 1.5 µg/mL extender increased post-thawed catalase, DPPH, sperm IPM, viability, and sperm motility and decreased MDA levels (p &lt; 0.05) than those of control group. Conclusion: This study was the first in which EGCG CNPs were used in SM–EY extender, and the addition of only 1.0 µg/mL of EGCG CNPs in this extender increased the antioxidant capacity and post-thawed quality of Kacang buck semen.

Effect of Different Thawing Methods for Frozen Bull Semen and Additional Factors on the Conception Rate of Dairy Cows in Artificial Insemination.

Simple SummaryToday, recommendations for thawing methods for frozen bull semen vary, and clear data to assess their influence on fertility are contradictory. Under present practical conditions, no differences between the three different thawing methods could be detected, so no clear recommendation for semen thawing methods in dairy reproduction can be made based on our data. Study results provide evidence that inadequate reproductive performance of high-producing, lactating dairy cows is a multifactorial consequence of farm and fertility management; accordingly, the livestock industry should focus more on cow health to avoid reproductive disorders and further improve the reproductive performance of dairy cows in the future.Recommendations for thawing methods of frozen bovine semen vary and clear data evaluating their influence on fertility are contradictory. In this respect, the aim of this study was to investigate the influence of different thawing methods of frozen bull semen in artificial insemination (AI) of dairy cows on conception rate (CR) under practical conditions and to determine further possible influencing factors on the success of AI in order to provide recommendations for practical use. From 2017 to 2019, 3393 AI were performed in a dairy farm in eastern Germany, distributed randomly into three groups of thawing methods: group A: n = 426 (11 s, 38 °C water bath); group B: n = 348 (35 s, 38 °C water bath); group C: n = 385 (30 s, “in the cow”). We observed no significant difference in CR from the general linear mixed model between the thawing methods (method A/B/C, 28.5%/26.6%/24.7%), but data analysis revealed effects of lactation number, month of insemination and AI method (natural heat vs. OvSynch) on CR. Based on our data, no clear recommendation for semen thawing method in dairy reproduction can be made. Our findings suggest that the main factors of influencing reproductive performance in the field are represented by the cow-side of fertility, e.g., insemination in natural heat, lactation number and season of insemination. Therefore, dairy farmers should focus more on cow conditions to further improve reproductive performance.

Proteomic analysis of donkey sperm reveals changes in acrosome enzymes and redox regulation during cryopreservation

Sperm cryoinjuries caused by cryopreservation restrict the application of donkey frozen semen in artificial insemination (AI). Identification of differentially represented proteins in fresh and frozen-thawed spermatozoa is of great significance to optimize the cryopreservation process and modify the component of cryopreservation extender. In this study, protein samples prepared from fresh (F) and frozen-thawed (FT) donkey spermatozoa were compared. 2682 proteins were quantitatively identified by tandem mass spectrometry (TMT) polypeptide labeling technique and LC-MS/MS method, of which 28 were more abundant in thawed samples and 147 in fresh spermatozoa. The differential abundant proteins (DAPs) were analyzed by bioinformatics. Most of the DAPs in intensive bioinformatic analysis were involved in the process of regulation of biological process and metabolism. Functional protein analysis showed that DAPs process mainly protein hydrolase activity and oxidoreductase activity. Cellular Component analysis showed that DAPs were related to vesicle transport and membrane system. This is the first analysis and study on differential proteomics of donkey sperm proteins before and after cryopreservation, which has a certain guiding significance for studying the mechanism of sperm damage caused by cryopreservation and improving the freezing and thawing procedure. SignificanceIn recent years, the commercial value of donkey products has been discovered. Improving the breeding efficiency of donkeys can save the stock of donkeys which is decreasing rapidly, and allow people to continuously benefit from the nutritional value brought by donkey milk.Sperm cryopreservation technology has laid the foundation for encouraging the spread of artificial insemination in donkey reproduction, but the freezing and thawing process causes damage to sperm, which dramatically reducing the viability of frozen sperm and leading to low fertility. At present, the mechanism of damage to donkey sperm caused by cryopreservation is still unclear, and studying this mechanism can provide a direction for improving the quality of frozen semen.Protein is a potential key factor affecting sperm cryopreservation activity. Studying changes in the sperm proteome during cryopreservation can provide promising evidence for revealing sperm cryopreservation damage, which is of great significance for optimizing the cryopreservation process, improving the composition of cryopreservation extender, and seeking directions for improving the quality of frozen semen.

Relationship between the timing of insemination based on estrus detected by the automatic activity monitoring system and conception rates using sex-sorted semen in Holstein dairy cattle.

We investigated the optimal timing of artificial insemination (AI) for achieving pregnancy according to the onset/end of estrus detected by an accelerometer system in Holstein cattle. The conception rates of conventional semen were used as a reference. The conception rate from AI of sex-sorted semen was higher at −4 to 4 h (57.1%) from the end of estrus than those at −12 to −4 h (37.7%) and 12–20 h (30.3%), whereas AI at 4–12 h showed an intermediate conception rate (47.4%). Conversely, conception rates were similar in AI performed between 0 and 32 h from the onset of estrus. Regarding conventional semen, the interval from the onset and end of estrus did not affect conception rates. The present results suggest that the time of the end of estrus is the better indicator of optimal AI timing for sex-sorted semen than the onset of estrus.

Evaluation of adoption rate of frozen sexed semen artificial insemination technology adoption in Palang Village, Tuban Regency, East Java

A research group of Animal Science Faculty of Brawijaya University introduced and implemented Frozen sexed semen Artificial Insemination to 120 beef cattle farmers in Palang Village, Tuban Regency, East Java, from 2017 to 2019. The result of the program reported that the success rate of the technology is quite high, with the birth rate of male claves up to 80%. However, farmers’ adoption rate of the technology was relatively low. This research aims to evaluate factors that affected the adoption rate including the technology, characteristics of respondents, and the extension agents. Primary data were collected through a census of 120 farmers involved in the program and in-depth interviews with stakeholders. Secondary data were collected through related documents including reports of the programs, Statistics, and other related documents. This research utilized Quantitative and qualitative analyses. Data of the study indicated that respondents have neutral perceptions of the Frozen Semen Sexing Artificial Insemination. Although male calves relatively have a higher price, more than 50% of respondents did not expect specific sexing for the calves. In-depth interview data revealed that the success of the Artificial insemination technology is more valuable for the farmers rather than the sexing. Characteristics of respondents and the extension agents played significant roles in the adoption rate of the Frozen Sexed Semen Artificial Insemination technology adoption in Palang Village, Tuban Regency, East Java.

Motility and recovery of alpaca (Vicugna pacos) spermatozoa after centrifugation in a density gradient solution.

One of the factors limiting successful processing of alpaca (Vicugna pacos) semen is the viscosity of seminal plasma. The viscous nature of the collected ejaculate has hindered sperm cryopreservation as well as artificial insemination (AI) under field conditions. The objective of this investigation was to evaluate recovery, motility, and plasma membrane integrity of alpaca spermatozoa after centrifugation in one of two different solutions at one of three different combinations of speed and time. A total of 24 ejaculates was recovered from seven reproductively sound Huacaya males using a modified artificial vagina (AV) after training the animals for semen collection. A 2 × 3 factorial treatment arrangement was utilized for this study. Ejaculates were divided into fractions for centrifugation in one of two solutions (Tris extender or PureSperm®80 density gradient solution) at one of three combinations of speed and time (492 × g for 15 min, 1968 × g for 10 min, or 4448 × g for 7 min). The experiment was replicated eight times. Analysis revealed that centrifugation at 4448 × g for 7 min in PureSperm®80 provided a high recovery rate of spermatozoa with the highest sperm motility and functional integrity of plasma membrane post-centrifugation. Conclusion: Results suggest that adoption of this procedure (centrifugation at 4448 × g for 7 min in PureSperm®80) in the initial processing of alpaca ejaculates may enhance subsequent ability to use semen for AI and other assisted reproductive biotechnologies in this species.

Artificial insemination of cattle: Description and assessment of a training program for veterinary students

The objective was to assess the effectiveness of a comprehensive artificial insemination (AI) training program designed to facilitate an understanding of the breadth of the AI process, including AI skill acquisition, for preclinical veterinary students. Participants (n = 303) were enrolled at the Ross University School of Veterinary Medicine (Basseterre, St. Kitts, West Indies). The 2-d AI training program (n = 20) consisted of ∼8 h of instruction and ∼8 h of demonstration and hands-on activity. Oral presentations were used to deliver educational content, followed by video clips, discussion, demonstrations, and hands-on activity. Reproductive anatomy and physiology of the estrous cycle, AI sire acquisition, collection, evaluation, cryopreservation and distribution of conventional and sexed semen, storage and handling of frozen semen, use of synchronization protocols, accurate and efficient detection of estrus, and correct AI technique were discussed. True or false pre- and posttests were used to determine the level of knowledge gained by participants during the AI training program. Preclinical veterinary students were required to complete a semen handling and AI technique practical exam to achieve a certificate of completion. Participant program evaluations conducted at the conclusion of the program indicated that veterinary students found the content, structure, discussion, demonstrations, and hands-on activities to be appropriate and useful. No negative comments were offered about the training program, instructor, or activity coinstructors. The AI training program increased the posttest knowledge scores of veterinary students by 22 percentage points. Only 1 participant was unable to achieve a certificate of completion due to failure of the semen handling and AI technique practical exam. These results provide evidence that the AI training program was relevant and effective and that it offered information and skill acquisition with immediate field application.

Timing of artificial insemination using fresh or frozen semen after automated activity monitoring of estrus in lactating dairy cows

The objective of this observational experiment was to determine the association between the time of artificial insemination (AI) and pregnancy per AI (P/AI) in lactating Holstein cows inseminated with either fresh or frozen semen considering different characteristics of an estrus event (i.e., onset, peak, and end) using an automated activity monitoring system. A total of 3,607 AI services based on the alert of an automated activity monitoring system (Heatime; SCR Engineers Ltd., Netanya, Israel) were evaluated from 4 commercial dairy farms in Germany. Pregnancy diagnosis was performed by transrectal palpation 38 ± 3 d after AI or by transrectal ultrasonography 30 ± 3 d after AI. Estrus intensity was categorized based on peak activity of estrus (PAE) into low (35-89 index value) and high (90-100 index value) intensity. The mean (± standard deviation) duration of an estrus event was 14.3 ± 4.6 h. The mean (± standard deviation) interval from onset of estrus (OE; moment where index value was ≥35) to AI was 16.8 ± 8.0 h, from PAE to AI was 11.9 ± 8.1 h, and from end of estrus (EE; moment where index value returned to <35) to AI was 2.5 ± 8.7 h. Primiparous cows had greater P/AI than multiparous cows, whereas first AI postpartum yielded greater P/AI compared with subsequent AI services. Type of semen was not associated with P/AI. Cows with heat stress 1 wk before AI had decreased P/AI. Cows with low estrus intensity (26.0%) were less fertile compared with cows showing high estrus intensity (32.8%). Cows with intermediate 100-d milk yield had decreased P/AI compared with cows with either low or high 100-d milk yield. There was a quadratic effect of the interval from OE to AI on P/AI. At 38 d after AI, P/AI was greatest for cows inseminated from 7 to 24 h after OE, within 18 h after PAE, or from 5 h before EE to 12 h after EE. There was no interaction between the interval from OE to AI and type of semen. There tended to be an interaction between the intervals from PAE to AI and type of semen and from EE to AI and type of semen. Cows inseminated with fresh semen within 5 h before EE had greater P/AI compared with frozen semen, whereas cows inseminated with frozen semen from 13 to 18 h after EE had greater P/AI compared with fresh semen. In conclusion, inseminating cows from 7 to 24 h after OE or 1 to 18 h after PAE yielded greatest P/AI irrespective of type of semen. In addition, high estrus intensity was positively associated with P/AI.

Does the Act of Copulation per se, without Considering Seminal Deposition, Change the Expression of Genes in the Porcine Female Genital Tract?

Semen—through its specific sperm and seminal plasma (SP) constituents—induces changes of gene expression in the internal genital tract of pigs, particularly in the functional sperm reservoir at the utero-tubal junction (UTJ). Although seminal effects are similarly elicited by artificial insemination (AI), major changes in gene expression are registered after natural mating, a fact suggesting the act of copulation induces per se changes in genes that AI does not affect. The present study explored which pathways were solely influenced by copulation, affecting the differential expression of genes (DEGs) of the pre/peri-ovulatory genital tract (cervix, distal uterus, proximal uterus and UTJ) of estrus sows, 24 h after various procedures were performed to compare natural mating with AI of semen (control 1), sperm-free SP harvested from the sperm-peak fraction (control 2), sperm-free SP harvested from the whole ejaculate (control 3) or saline-extender BTS (control 4), using a microarray chip (GeneChip® porcine gene 1.0 st array). Genes related to neuroendocrine responses (ADRA1, ADRA2, GABRB2, CACNB2), smooth muscle contractility (WNT7A), angiogenesis and vascular remodeling (poFUT1, NTN4) were, among others, overrepresented with distal and proximal uterine segments exhibiting the highest number of DEGs. The findings provide novel evidence that relevant transcriptomic changes in the porcine female reproductive tract occur in direct response to the specific act of copulation, being semen-independent.

Effects of timing of artificial insemination and treatment of semen with a Slo3 potassium channel blocker on fertility of dairy heifers subjected to the 5-day CIDR-Synch protocol

Two experiments were conducted to evaluate the effects of the timing of artificial insemination (AI) and incorporation of the Slo3 K+ channel blocker 4-(4-chlorophenyl)butyl-diethyl-heptylammonium to semen extender (CSE) on pregnancy per AI (P/AI) and pregnancy loss in dairy heifers. In experiment 1, Holstein heifers were subjected to the 5-d CIDR-Synch protocol: d -8 GnRH and controlled internal drug-release device (CIDR); d -3 PGF2α and CIDR removal; d -2 PGF2α; d 0 GnRH) and assigned randomly to receive timed AI with control semen on d 0 (72-CON; n = 104), control semen on d -1 (48-CON; n = 100), or CSE-treated semen on d -1 (48-CSE; n = 98). Heifers were fitted with collar-mounted automated estrus detection devices to monitor physical activity and rumination. In experiment 2, Holstein heifers were subjected to the 5-d CIDR-Synch protocol and received a mount detection patch at the first PGF2α injection. Heifers detected in estrus before d 0 were inseminated on the same day, whereas those not detected in estrus received the second GnRH injection and timed AI on d 0. Heifers were assigned randomly to receive AI with control (AI-CON; n = 148) or CSE-treated semen (AI-CSE; n = 110). Four bulls with proven fertility were used in both experiments, and ejaculates from each sire were divided and processed as CON or CSE. Pregnancy was diagnosed by transrectal ultrasonography at 29 and 54 d after AI. Data were analyzed by logistic regression, and statistical models included the fixed effects of treatment and enrollment week. In experiment 1, orthogonal contrasts were built to assess the effects of day of AI (72-CON vs. 48-CON + 48-CSE) and treatment of semen with CSE (48-CON vs. 48-CSE). Pregnancy per AI on d 29 (72-CON = 60.8, 48-CON = 35.2, 48-CSE = 39.8%) and d 54 (72-CON = 58.2, 48-CON = 31.6, 48-CSE = 36.2%) was greater for heifers inseminated on d 0 compared with d -1. However, no effect of semen extender on P/AI was observed in heifers inseminated on d -1. In experiment 2, P/AI tended to be greater for AI-CSE than for AI-CON on d 29 (58.6 vs. 47.3%) and d 54 after AI (55.6 vs. 43.7%). Advancing AI by 24 h decreased the likelihood of pregnancy, and use of CSE was unable to overcome the expected asynchrony between insemination and ovulation. Nevertheless, incorporation of CSE in semen processing tended to improve P/AI when heifers received AI upon detected estrus or timed AI concurrently with the final GnRH of the 5-d CIDR-Synch protocol.

Antibiotic resistance in microorganisms isolated in a bull semen stud.

Many microorganisms from various sources may be present in ejaculates of bulls. This study identified and isolated bacteria from bull sperm samples in a commercial stud and evaluated their resistance to antibiotics. The number of colony-forming units was determined in semen samples collected at distinct steps during freezing and thawing. The minimum inhibitory concentration and the minimum bactericidal concentration were determined for four antibiotics commonly used in commercial studs. A total of 135 microorganisms from 25 genera were isolated. After a sensitivity test, all evaluated microorganisms (n=55) were resistant to penicillin and most of them were resistant to tylosin and lincomycin (n=54). Resistance to all tested antibiotics was observed in 22% of all isolates, whereas only 3.9% of the isolates were inhibited by the tested antibiotics at the concentrations recommended by the international legislation. As the isolated microorganisms presented high resistance to frequently used antibiotics, sensitivity tests should be periodically conducted in commercial bull semen studs to prevent the use of contaminated semen in artificial insemination.

Cryoprotectants used in buck semen preservation: A review

Goat production is gradually changing from low input extensive system to agri-business model under semi-intensive and intensive systems on commercial production. Accordingly, semen freezing and artificial insemination (AI) is gaining demand among stakeholders in goat husbandry. The composition of buck semen diluent and freezing protocol have been standardized over the years and the research results revealed wide variation in post-thaw seminal traits. This review discusses in detail about various cryoprotective agents (CPAs), their classification, their level, various combinations used in buck semen freezing and also recent advances in cryoprotectants for improving post-thaw recovery of buck sperm. Among different cryoprotectants, 6% glycerol as permeable and 10% egg yolk as non-permeable CPAs yielded satisfactory post-thaw sperm motility (> 40%) with functional quality for successful fertility. The alternative CPAs viz., dimethyl sulfoxide (DMSO), ethylene glycol and dimethyl formamide yielded 13.80 to 21.78%, 12.86 to 31.79% and 13.40 to 18.10% post-thaw motility, respectively. However, the combination of glycerol + DMSO and glycerol + propylene glycol yielded 26.2 to 60.0% post-thaw motility. The use of universally accepted glycerol (6%) and egg yolk (10%) in buck semen preservation is sufficient in liquid and frozen buck semen for AI. However, it is necessary to standardise the levels and temperature of commonly used CPAs breed-wise for higher post-thaw recovery and fertility.

Effect of Timing of Postovulatory Insemination Relative to Human Chorionic Gonadotropin/Buserelin Treatment With 1 Straw of Frozen-Thawed Semen on Mare Fertility

The reproductive management of mares for frozen semen artificial insemination (AI) can be costly and labor intensive. Predicting the exact time of ovulation can be challenging even when ovulation-inducing drugs are used. The main objective of this retrospective study was to determine whether there was an effect of interval between examinations to detect ovulation on likelihood of pregnancy and early embryonic loss in mares after postovulatory breeding with a single straw of frozen/thawed semen. The second objective was to determine the efficacy of two different drugs (human chorionic gonadotropin vs. buserelin) for timely induction of ovulation. The length of the interval from penultimate check to ovulation had no significant effect on pregnancy or embryo loss rates (4 hours: 34.1% and 13.3% vs. 8 hours: 26.1% and 0% and 16 hours: 34.5% and 10%, respectively) nor did the ovulation-inducing drug used, number of the cycle, or the stallion. In conclusion, there appears to be no advantage of checking mares for ovulation during the late evening and night hours when using a postovulatory AI protocol and ovulation-inducing drugs.