Conventional Artificial Insemination Research Articles

Effects of natural mating, artificial insemination and intravaginal deposition of raw semen or seminal plasma on vaginal and uterine blood flow in German Holstein cows

AimThe present study was performed to characterize and compare the perfusion of vaginal and uterine arteries after challenging the reproductive tract of dairy cows via natural mating, artificial insemination (AI), or intravaginal deposition (vaginal fundus) of different biological fluids or a placebo.Materials and methodsIn a double-blind study, six German Holstein cows were administered PGF2α during dioestrus and 48 h later treated with GnRH. Intravaginal or intrauterine treatments were carried out 12 h after GnRH was administered. Animals served as their controls, using a cross-over design with an interval of 14 days between experiments. The experimental animals were allocated to receive the following treatments: natural mating (N), intrauterine artificial insemination (A), intravaginal deposition (vaginal fundus) of 6 mL raw semen (R) or 6 mL seminal plasma (S), and compared to their controls [control 1: 6 mL placebo (P: physiological saline); control 2: no treatment (C)). Corresponding time intervals were chosen for the untreated control oestrus. Blood flow volume (BFV) in the uterine (u) and vaginal (v) arteries ipsilateral to the ovary bearing the preovulatory follicle was determined using transrectal Doppler sonography.ResultsAll animals exhibited oestrus and ovulated between 30 and 36 h after GnRH. Transient increases (P < 0.05) in vaginal blood flow occurred between 3 and 12 h following mating as well as 3 to 9 h after deposition of raw semen and seminal plasma, respectively. The most distinct increases (199%) in vBFV occurred 6 h after mating compared to values immediately before mating (= time 0 h). Neither AI nor deposition of a placebo into the vagina affected vBFV (P > 0.05). Only mating and deposition of either raw semen, seminal plasma or AI increased uBFV (P < 0.003). The greatest rise in uBFV occurred after natural mating. Maximum uBFV values were detected 9 h after mating when values were 79% greater (P < 0.05) than at 0 h.ConclusionsThe natural mating, deposition of raw semen or seminal plasma and conventional AI affect vaginal and/or uterine blood flow to different degrees. The factors responsible for these alterations in blood flow and their effects on fertility remain to be clarified in future studies.

Cattle Artificial Insemination Service in Developing Countries: Efficiency, Major Challenges and Economic Loss: A Review

This review paper summarizes information on the efficiency, major challenges and economic loss of cattle Artificial Insemination (AI) service in developing countries. Efficiency of AI service can be measured by number of services per conception (NSC), conception rate at first insemination, and calving rate (CR). The optimum recommended NSC for profitable dairy cow ranges from 1.0-2.0. The averages of NSC of the conventional AI (1.73) and fixed time AI (1.78) in the reviewed publications were in the ranges of the recommendations of NSC. The NSC varies with animal breeds, animal factor (body condition score, age and parity), semen factor (handling procedure and quality), inseminator factor (knowledge, skill and experience), production systems, management level provided and AI breeding methods. The NSC and calving rate vary with conventional AI and fixed time AI breeding methods. Likewise, calving rate (CR) is influenced by poor semen quality, poor semen handling procedure, inadequate insemination skill, poor oestrus detection and wrong time of insemination. The average success rate (CR) of conventional AI (35.15%) in the reviewed publications is far below the success rates reported in some developing countries. Nevertheless, widespread use and longtime use of AI service on selected genotype(s) can cause cattle biodiversity loss. Dairy producers incur additional costs when cows fail to conceive at their first AI services. Moreover, challenges of AI service comprised of feed scarcity, animal diseases, climate change, poor AI infrastructure, poor livestock husbandry practices, weak livestock extension systems and incapability of Artificial Insemination Technicians (AITs). This calls designing suitable interventions to improve the efficiency of AI services. Adequate feed and high level of management should be provided to the breedable cows and heifers. AI service centers should be established as per the recommended number of breedable cows and heifers. AI inputs including AITs should be always available at each AI service center, and proper AI service recording should be practiced. Sexed semen should be used to enhance the number of replacement heifers, and capacity building should be provided to AITs and community cattle breeders. Radio, television and printed medias should be used to enhance the awareness of the community cattle breeders. Frequent extension support is essential for the success rate of the AI service.

PSIII-9 Field fertility following the practice of post-cervical artificial insemination (PCAI) at multiple North American swine units

Abstract On a global scale, greater than 95% of sows are bred using artificial insemination (AI). As with most technologies, efficiencies improve over time and in the case of swine AI the industry is moving towards fewer sperm per dose in conjunction with a post-cervical deposition (PCAI). Nevertheless, little information is available stating the fertility of farms actively using PCAI. The objective of this research is to provide a retrospective report on the field fertility of multiple farms in North America utilizing PCAI. As a reference, information is provided for contemporary farms utilizing conventional AI (intra-cervical deposition in conjunction with a greater total sperm count per dose). Semen doses produced for PCAI (1.5 billion total cells in 40 mL volume) sourced from one boar stud located in Tennessee and are packaged as pooled semen in NUTRIXcell + extender. Semen was held overnight at 18°C and delivered to seven farms the next day. Semen doses produced for conventional AI (CONAI) also sourced from a single boar stud located in Michigan; packaged as pooled semen at 2.75 billion total cells in a 70 mL volume using the NUTRIXcell + extender and shipped to six farms the same day as semen production. Both PCAI and CONAI were used on 100% of gilts and multiparous sows in respective systems. Field fertility, reported as farrow rate (FAR) and mean total born (TB), is reported below for both PCAI (Table 1) and CONAI (Table 2) following use per individual farms during January 2022 to September 2023. Results suggest that PCAI can maintain acceptable levels of fertility and should enable cost savings in conjunction with increased dissemination of superior genetics.

283 Identification of new or existing risk factors associated with the development of sow pelvic organ prolapse

Abstract A survey was conducted between March and December of 2022 to examine the variation between farms that had high and low pelvic organ prolapse (POP) rate. The objective was to identify new or existing risk factors associated with the development of POP, which could open new avenues for further investigation. Sow farms (n = 53) across 26 production systems located in the US, Canada, and Mexico were used. Sampling of farms was not random. High and low POP systems were selected within each region as well as high and low POP farms within each system. Over 800 variables related to general farm information and management, performance traits, reproductive management, replacement gilt management, gestation and farrowing practices, labor and health management, and nutrition were collected during farm visits. To be included in the analysis, at least 70% of observations were needed for continuous variables with at least 10% of observation for each category for categorical variables. Univariable models were fitted to identify variables associated with annualized POP rate for 2021. Variables with P ≤ 0.10 were selected for further analysis, with 94 predictor variables selected for principal components analysis (PCA). A factor analysis of mixed data was conducted, and results were then fitted into a hierarchical clustering on PCA, which segregated the data into three clusters: 2 with low POP (2.5%) and 1 with high POP (6.1%) prevalence (low vs high P &amp;lt; 0.05). The resulting clusters explained 33.7% of the variability in annualized 2021 POP rate. Differences between clusters were evaluated by Kruskall-Wallis test for numerical variables and chi-square test for categorical variables. High POP cluster farms had greater total piglets born over the years, greater number of sows per worker, greater annual gestation feed usage, and a lower mean body condition score at 16 wk of gestation compared with low POP cluster farms. High POP cluster farms had a decreased proportion of farms using conventional artificial insemination, a greater proportion of farms utilizing cup waterers in gestation for sows in group housing and in farrowing, and greater proportion of farms with a routine sleeving practice. High POP cluster farms compared with low POP cluster farms had greater gestation distillers dried grains with solubles (DDGS) inclusion level (14.6% vs 4.0%, SE 3.02), greater levels of standardized total tract digestibility (STTD) P% (0.49% vs 0.39%, SE 0.014), narrower analyzed Ca to STTD P ratio (1.7 vs 2.2, SE 0.06), and lower phytase inclusion and release (0.16% vs 0.09%, SE 0.014). These variables were also the predictors with the greatest R2 values in the univariable models. These observations suggest further research is needed to evaluate the connection between dietary Ca and P and pelvic organ prolapse.

A REVIEW ON EFFICIENCY OF ARTIFICIAL INSEMINATION IN CATTLE BREEDING IN ETHIOPIA

Ethiopia has large cattle population in Africa. The output of decades of crossbreeding programme in Ethiopia through AI service was quite insignificant because the exotic breeds and their crossbreds of the country accounted for about 1.44%. The objective of this review is to present the efficiency of Artificial Insemination (AI) service in cattle breeding in Ethiopia. The optimum recommended mean number of services per conception (NSC) for profitable dairy cow is about 1.4. However, conventional cattle AI breeding indicated that the mean NSC of different studies ranged from 1.14 in local cows up to 2.47 in different genotypes of cows kept under different management systems and conception rate at first insemination (CR1) ranged from 7.14% to 75.5% in different genotypes of dairy cows kept under extensive and intensive management systems. Estrus synchronization followed AI breeding indicated that CR1 ranged from 24.69% to 70.6% in Zebu cows kept under semi-intensive management system. Calving rate (CR) is the most appropriate measure of fertility of dairy cows which is defined as the number of calves born per 100 services. The poor efficiency of the country cattle AI service is a huge biological economic loss in cattle production and managerial monetary losses. Strategic interventions on cattle AI service efficiency improvement options should be identified and practiced considering breed type, production system and agro-ecology.

Health assessment of Holstein calves born after in vitro fertilization, biopsy-based genotyping at the blastocyst stage and subsequent embryo transfer

Establishing methods for evaluating genomic estimated breeding values of bovine embryos can potentially increase the efficiency of breeding programs by transferring only embryos with a high genomic estimated breeding value. This may be achieved by analyzing DNA from trophectoderm biopsies. However, manipulation of bovine embryos is associated with a risk of impaired conceptus health. More knowledge on the health implications of embryonic handling procedures is required. In this study, we followed pregnancies after transfer of in vitro-produced (IVP) embryos and assessed the health of the offspring during the first 2 weeks of life. Three groups of calves were studied: i) freshly transferred non-biopsied embryos (39 transfers, 17 calves; Group B-/C-); ii) biopsied and freshly transferred IVP embryos (42 transfers, 21 calves; Group B+/C-); iii) biopsied and cryopreserved IVP embryos (17 transfers, 6 calves; Group B+/C+). Blood biochemical and hematologic values were compared between groups and to a control group of 13 calves produced by conventional artificial insemination. The pregnancy rate on day 50 and the calving rate did not differ among the groups, but the average gestation length of the B+/C+ group was significantly shorter and with wider variation than the two other groups. There was a tendency toward a higher average body weight at birth in group B+/C+ (45.1 kg) and the standard deviation in body weight was larger (11.7 kg) compared to the B-/C- (39.5 kg; 3.2 kg) and B+/C- (41.8 kg; 6 kg) groups. Body weight on day 14 was higher in the B+/C+ calves compared to the other groups. There was no difference in the biochemical and hematological values at birth between the groups and these were within the normal range. However, when compared to a group of calves produced by standard artificial insemination, significantly higher concentrations were found for the hepatic-related enzymes ALAT, ASAT, ALP, and GGT in group B-/C-and B+/C-, while only higher ALP concentrations were found in B+/C+ calves. The biochemical findings indicate higher heterogeneity in IVP calves compared to calves produced by artificial insemination. The more manipulated IVP embryos also showed increased heterogeneity in body weight at birth, with a shift toward heavier calves, which calls for closer attendance at parturition to handle dystocia in a timely manner and minimize fetal losses.

N-Carbamylglutamate Improves Reproductive Performance and Alters Fecal Microbiota and Serum Metabolites of Primiparous Sows during Gestation after Fixed-Time Artificial Insemination.

Simple SummaryLarger litter size (born alive) and higher uniformity of piglets’ birth weight are the most desired characteristics in pig production. Application of N-carbamylglutamate (NCG) was shown to increase litter size and decrease the coefficient of variation of piglets’ birth weight from sows after conventional artificial insemination. In this study, we report that, in sows after fixed-time artificial insemination (FTAI), NCG improved the number of piglets born alive and the coefficient of variation of birth weight through direct effects (increased serum NCG levels) and indirect effects (altered intestinal microbiome and serum metabolites). These findings indicate that NCG can improve reproductive performance by improving both the number of piglets born alive and the uniformity of piglets’ birth weight in sows after FTAI.N-carbamylglutamate (NCG) supplementation during gestation improves reproductive performance in sows after conventional artificial insemination. However, whether NCG can improve reproductive performance and change fecal microbiota and serum metabolite levels during pregnancy in sows after fixed-time artificial insemination (FTAI) remains unclear. Two hundred multiparous sows were assigned a diet from mating until farrowing: control (corn–soybean meal) or NCG supplementation (0.05% NCG). At days 30, 70, and 110 of gestation and after farrowing, maternal microbial diversity and serum metabolites were studied. Supplementation of NCG increased the number of piglets born alive and the litter weight (all p < 0.05) and altered the fetal microbial community during gestation. Some genera were particularly abundant at different time points during gestation and after farrowing, but none were commonly abundant across all four time points. Metabolic analysis revealed that NCG supplementation significantly increased the serum concentrations of NCG, ferulic acid, cinnamoylglycine, 3-phenyllactic acid, and gamma-glutamylglutamic acid in the NCG group compared with levels in the control group. Our results reveal that NCG supplementation during gestation improves reproductive performance in sows after FTAI, exerting both direct (increased serum NCG levels) and indirect effects (altered intestinal microbiome and serum metabolites) on sow reproduction and, ultimately, improving placental and fetal development.

Live cells are not affected by dead sperm in liquid boar semen: New insights based on a thermo-resistance test.

This study evaluated the effect of different proportions of dead spermatozoa on the quality of liquid boar semen during a thermo-resistance test (TRT). After 3 days of storage (17°C), 54 conventional artificial insemination semen doses (~23 × 106 sperm/ml in ~88 ml of BTS) were split into three 15 ml-treatments (25%, 50%, and 75% dead sperm cells) by mixing two subsamples containing 75% (I) and 0% (II) of live cells. Spermatozoa were evaluated after TRT at 30 (on-test) and 300 min (off-test) incubation at 38°C. At the on-test, treatments of 25%, 50%, and 75% dead sperm cells showed medians for total sperm motility of 77.6%, 50.2%, and 25.6%, respectively. Considering the absolute variation of sperm motility during TRT, doses with 25% dead sperm lost more percentage points (pp) (-9.4pp) compared to doses containing 50% (-8.2pp) and 75% dead sperm (-4.5pp). The lowest loss was observed for doses with 75% dead sperm (p < .01). However, data showed that treatments lost similar proportion of motile cells over the TRT: 25% dead sperm=-11.9%, 50% dead sperm=-16.0%, and 75% dead sperm=-17.5% (p=.31). Regarding the flow cytometry parameters (plasma and acrosomal membrane integrity, mitochondrial activity of cells with intact plasma membrane, high degree of lipid disorder, and apoptotic cells), the absolute variations did not surpass values of -1.8, 3.4, -5.4, and 4.7pp, respectively. Furthermore, the relative variation suggested that dead sperm did not substantially change their values over the TRT. In conclusion, dead sperm cells did not influence the quality of contemporary live cells during the period and in conditions of a TRT.

Wilsher cervical forceps for artificial insemination technique in jennies

The pregnancy rate after artificial insemination (AI) with fresh semen between jennies and mares seems to be similar. However, the jenny's cervix differs from the mare, it's longer and tortuous, being difficult the passage through the cervix to perform different reproductive procedures such as AI or embryo transfer. This retrospective study aimed to compare the pregnancy rate in jennies using two different methods of fresh semen AI. Eight native Argentinian jennies were used, characterized by a small body mass index, between 150 and 250 kg of body weight, and an average height of 1.20 m. Nineteen AI cycles performed between the 2019-2020 breeding season in Argentina were analyzed. Ovulation was induced during estrus using 1500 IU of hCG (Human Chorionic Gonadotropin, Ovusyn®, Zoetis) at the evidence of a preovulatory follicle ≥ 35 mm. They were inseminated with semen from two donkeys of proven fertility. An ultrasound was performed every 24h until ovulation and the interval between AI and ovulation was 12 to 48h. The jennies were evaluated by ultrasound, 15 days post ovulation for pregnancy diagnosis. For AI, two techniques were used: 1) conventional artificial insemination (n=11), where the AI catheter was inserted by hand through the vaginaand the fingers guided it through the cervix to the uterus, and 2) the Wilsher technique (n=8) which has been originally described for equine embryo transfer. The Polansky speculum was introduced in the vagina, the cervix was visualized with the aid of a flashlight and taken from the ventral segment with the Wilsher forceps. The pointed upper jaw of the opened forceps was inserted into the external os of the cervix and forceps jaws were closed grasping firmly the ventral segment of the cervix. To straighten the cervix and cervical canal the Wilsher forceps were pulled backward, and an AI catheter was inserted through the cervix to the uterus. A Fisher's exact test was performed to evaluate the pregnancy rate 15 days post ovulation. For statistical analysis, p<0.05 was considered statically significant. Pregnancy rates per cycle using conventional (54.5% (6/11)) or Wilsher forceps technique (75.0% (6/8)) were not statistically different (p=0.63). Our preliminary results suggest that both AI techniques are suitable to achieve high pregnancy rates per cycle although the application of Wilsher technique can be a specially useful tool in AI of small donkey breeds. In general, this technique is easier and faster than conventional jenny's AI due to her long and tortuous cervix. More experimental data are needed to confirm these results.

Timed artificial insemination in crossbred mares: Reproductive efficiency and costs.

Timed artificial insemination (TAI) has boosted the use of conventional artificial insemination (CAI) by employing hormonal protocols to synchronize oestrus and ovulation. This study aimed to evaluate the efficiency of a hormonal protocol for TAI in mares, based on a combination of progesterone releasing intravaginal device (PRID), prostaglandin (PGF2α ) and human chorionic gonadotropin (hCG); and compare financial costs between CAI and TAI. Twenty-one mares were divided into two groups: CAI group (CAIG; n=6 mares; 17 oestrous cycles) and TAI group (TAIG; n=15 mares; 15 oestrous cycles). The CAIG was subjected to CAI, involving follicular dynamics and uterine oedema monitoring with ultrasound examinations (US), and administration of hCG (1,600IU) when the dominant follicle (DF) diameter's ≥35mm+uterine oedema+cervix opening. The AI was performed with fresh semen (500×106 cells), and embryo was recovered on day 8 (D8) after ovulation. In TAI, mares received 1.9g PRID on D0. On D10, PRID was removed and 6.71mg dinoprost tromethamine was administered. Ovulation was induced on D14 (1,600IU of hCG) regardless of the DF diameter's, and AI was performed with fresh semen (500×106 cells). On D30 after AI, pregnancy was confirmed by US. The pregnancy rate was 80.0% in TAIG and 82.3% in CAIG (p>.05). The TAI protocol resulted in 65% reduction in professional transport costs, and 40% reduction in material costs. The TAI was as efficient as CAI, provided reduction in costs and handlings, and is recommended in mares.

Influence of transcervical infusion of seminal plasma on the farrowing rate and litter size in artificially inseminated sows

ABSTRACT Recent studies have focused on the use of seminal plasma to increase sow fertility after classical intracervical artificial insemination (AI). The aim of the present study was to investigate the influence of seminal plasma infusion, prior to the application of conventional AI dose, on the fertility rate in sows. A total of 114 sows were treated with intrauterine infusion of 30ml seminal plasma (SP), while 114 control sows were infused by physiological solution (PS), immediately before the application of conventional AI dose. The experiment was conducted at one commercial pig farm in Serbia, which is comprised of 1,500 sows in the breeding herd. Intrauterine infusion of seminal plasma produced significantly (P&lt;0.05) higher farrowing rate (93.8%) and significantly (P&lt;0.01) more live-born piglets per litter (12.27), compared with the control sows (83.33% farrowing rate and 10.48 piglets). The present results show that intrauterine infusion of seminal plasma can be a useful tool for increasing the fertility rate in artificially inseminated sows, under the conditions of practical intensive pig production.

Improved farrowing rate using intrauterine insemination in sows

Intrauterine insemination (IUI), a technique that uses a lower number of spermatozoa than conventional artificial insemination (CAI), could contribute to improve reproductive efficiency of boars. However, since some field trial reports show suboptimal performance for IUI, it is necessary to continue evaluating and standardizing this technique. In this work, the use of fixed reduced sperm amounts and doses volumes for IUI respect to CAI using the same semen samples was assessed. The results show an increase in the farrowing rate using IUI vs CAI (84.80 ± 0.36 vs 71.44 ± 2.63, P&lt;0.05). Parameters such as litter size, live piglets/litter, stillborn or mummified fetuses were analyzed as well and showed non-significant differences between techniques. Statistical positive correlation analyses showed a positive correlation between live piglets/litter and stillborn piglets and between stillborn and total number of piglets, only for CAI. In addition, the economic analysis showed a positive impact on the productivity of the farm, and possibly of the region, by lowering costs using IUI instead of CAI. In conclusion, the intrauterine insemination had a positive impact on the reproductive performance and on the economic parameters of porcine production.

Influence of nest boxes and claw abrasive devices on feather pecking and the fear responses of layer breeders in natural mating colony cages

Natural mating colony cages for parent-stock layer breeders, instead of conventional cages with artificial insemination, have been widely adopted by many commercial farms in China. Although some natural mating behaviours can be expressed and broader activity space is provided compared with that of conventional artificial insemination cages, the environment is still relatively barren. The aim of this study was to investigate the effects of providing nest boxes and claw abrasive devices (CADs) in this colony cage system on feather pecking (FP), feather condition, fear and physiological stress in layer breeders. Twelve treatments were compared in a factorial arrangement, including 2 types of nests (large and small), 3 types of CADs (abrasive strips, rubber mat with grooves, and metal plates with holes), and the control (without the provision of nests and CADs). Nine cages per treatment were involved, with 10 roosters and 90 hens per cage. The results showed that the nests had a significant effect (P ≤ 0.05) on the frequency of severe feather pecking (SFP); environmental pecking (ENP); food pecking (FOP); back, rump, and belly coverage condition; tonic immobility (TI) duration; avoidance distance (AD); and corticosterone and 5-HT concentrations. Except for the blood parameters, the CADs had a significant effect (P ≤ 0.05) on the frequency of SFP and FOP; back, rump, tail coverage condition; duration and latency of TI test; hens’ novel object (NO) recognition score; and distance in the AD test. In addition, significant nest × CAD interactions (P ≤ 0.05) were noted for SFP, ENP, and FOP; back, rump, and tail coverage condition; duration in the TI test; hens’ novel object (NO) recognition score; distance in the AD test; and the concentration of corticosterone. Mortality was significantly (P ≤ 0.05) reduced by nests, CADs and their interaction. It was concluded that the nests and CADs that were equipped in our study could be regarded as rewarding environmental necessities that could alleviate FP activities, improve feather coverage condition, and reduce stress levels and mortality rates. Large nests and abrasive strips were the preferred choice over colony cages without nests and CADs.

Expected value of crossbred dairy cattle artificial insemination breeding strategies in virgin heifers and lactating cows

Research on sexed semen breeding techniques has largely focused on purebred cattle production systems and little work has been done evaluating sexed semen use in crossbred dairy cattle. Complementing a crossbreeding reproduction strategy with sexed semen artificial insemination (AI) has the potential to increase profit potential of sexed semen technology in the short and long run. The objective of this project was to estimate and compare the expected net present value (NPV) of reproduction management programs considering several conventional and sexed semen breeding strategies, cow ages, and breed compositions. While the potential benefits of sexed semen are varied, it is important to note that the focus of this study is on the economic returns to the breeding program. This is not a life-cycle analysis, and therefore, only the sexed semen costs and returns that directly impact the returns to the breeding program are considered. Specifically, a NPV model that incorporates dystocia and stillbirth costs, in addition to improved fertility of crossbred cattle (over purebred cattle), directly into the expected NPV calculation is developed. Increased use of crossbred dairy cattle in the United States make this research particularly timely and relevant. Consistent with previous research, results indicate that pure conventional semen AI and a mixed strategy with one sexed semen AI followed by conventional semen were generally the preferred breeding strategies in terms of expected NPV across all breeds and dam ages evaluated. Similarly, our results also support previous findings that the expected NPV of breeding programs for virgin heifers were consistently higher than lactating cows. In terms of breeds, the crossbreed scenarios generally produced higher expected NPV than scenarios for purebred Holsteins. The most influential factors resulting in these higher returns were the higher cumulative pregnancy rates associated with the crossbreds. Reproductive benefits of crossbred dairy cattle may be able to alleviate some economic pressure currently associated with poor dairy reproduction with AI breeding strategies (especially those incorporating sexed semen). However, it is important to note the likely tradeoffs associated with improvements in fertility (e.g., reduced milk production), the consideration of which is necessary to maximize whole farm profitability.

Sudden Death Secondary to Bladder Rupture in an Ewe Undergoing Laparoscopic Insemination Procedure - A Case Report

Laparoscopic artificial insemination (AI) is an advanced assisted reproductive technique gaining popularity among small ruminant veterinarians due to the higher pregnancy rates it affords using frozen/processed semen. The technique has a distinct advantage over conventional AI techniques, in which it bypasses the caudal reproductive tract and the tortuous cervical rings and enables intrauterine deposition of semen. Prior to performing the actual procedure, it is advisable to withhold feed and water for 12-24 hours to decrease the rumen fill and afford greater visibility of the reproductive tract.

Pentoxifylline effects on capacitation and fertility of stallion epididymal sperm

The aims of this study were to determinate whether pentoxifylline (PTX) increases the motion parameters of fresh and frozen-thawed equine epididymal spermatozoa, to evaluate the tyrosine phosphorylation of frozen-thawed epididymal sperm in the presence of PTX and to determine whether the PTX-treatment of stallion epididymal sperm prior to freezing improves the fertility response of mares to a reduced number of spermatozoa per insemination dose. Fifty epididymis were flushed with a skim milk based extender with or without PTX. The pre-treatment with PTX enhanced the sperm motility after being harvested (P<0.05); however the freeze-thaw process did not alter the sperm kinematics between control and treated samples (P>0.05). Plasma membrane integrity did not differ between control and PTX group after recovery and after thawing (P>0.05), as observed in tyrosine phosphorylation, which the PTX treatment did not alter the percentage of tail-associated immunofluorescence of cryopreserved epididymal sperm (P>0.05). For the fertility trial, different insemination groups were tested: 800×106 epididymal sperm (C800); 100×106 epididymal sperm (C100); 100×106 epididymal sperm recovered in an extender containing PTX (PTX100). The conception rates for C800; C100 and PTX100 were 68.7% (11/16); 31.5% (5/16) and 50% (8/16), respectively. The conception rate did not differ among groups (P>0.05), however, a low number of animals was used in this study. A trend toward significance (P=0.07) was observed between C800 and C100 groups. In conclusion, PTX has no deleterious effect on sperm motility, viability and capacitation of cryopreserved stallion epididymal sperm. The conventional artificial insemination with 100×106 sperm recovered with PTX ensures acceptable conception rates and maximize the limited number of doses of cryopreserved stallion epididymal sperm.

Avaliação embrionária e fetal por ultrassonografia em fêmeas bovinas leiteiras mestiças submetidas à inseminação artificial ou inseminação artificial em tempo fixo*

Between the years 2013 and 2016 were used 31 crossbred cows of Gir and Dutch races, at different stages of gestation, multipara aged 4 and 8 years and body condition score (BCS) average 3 on a scale that ranged from 1 to 5 (1 very lean and 5 very fat) of the Federal Rural University of milk cattle production sector of Rio de Janeiro, Seropedica, RJ, in order to evaluate the embryonic and fetal development compared between insemination conventional Artificial (IA) and Artificial Insemination Fixed Time (TAI). Development parameters were evaluated axial and appendicular skeleton, as well as the allantois, amnion, and heart rate. The data obtained over the three years of evaluation in this study showed that ultrasound B-mode via transrectal, is a safe tool for pregnancy monitoring in the first trimester of the evaluated females, and the variables analyzed high reliability for the study of embryo viability and fetal bovine in the first trimester of pregnancy. The use of hormones for synchronization of ovulation and TAI did not influence the embryonic and fetal development of crossbred dairy cows, concluding that products from conventional AI and TAI present development pattern in the first trimester of pregnancy with no significant differences.

Status of Assisted Reproductive Technologies for Genetic Improvement of Dairy Cattle in Ethiopia: Review

This review is aimed to summarize and synthesize the fragmented information on effectiveness of assisted reproductive technologies (ARTs) for enhancing genetic improvement of dairy cattle in Ethiopia. Like most developing countries, artificial insemination (AI) is the first and most commonly used ARTs in Ethiopia because of its relative simplicity. It had been applied for nearly fifty years. In order to enhance efficiency of AI service and improve heat detection problem of the dairy farmers, oestrous synchronization and mass artificial insemination (OSMAI) had also triggered as second reproductive technology and management. Even though the conception rate of conventional AI service which was 27 % improved to 39.3% for hormone treated dairy cows, the total number of cross breed cattle is only 705,526 (1.22%) from 57.83 million cattle population of the country. Furthermore, currently, the average milk yield per cow per day at country level is about 1.37 liters and the average lactation period per cow is estimated to be about six months. This indicates that the access of genetically improved dairy cows for smallholder farmers and the reproductive and productive performance of dairy cows have continued with little change from natural mating. The main reasons for this insignificant change were interrupted AI service delivery system, discrepancy between time of heat detection and appropriate time of insemination, shortage of AITs and low output from the available technicians, lack of appropriate collaborations between service provider and other stakeholders and absence of herd recording system. In order to improve the effectiveness of the technologies and ultimately enhance access of smallholder farmers for improved dairy cattle, emphasis should be given on identified problems.

Cytological endometritis at artificial insemination in dairy cows: Prevalence and effect on pregnancy outcome

The aims of our field study in dairy cows were (1) to consolidate cytotape (CT) as a valid technique to diagnose cytological endometritis (CYTO) during artificial insemination (AI); (2) to establish a cutoff point concerning the polymorphonuclear cells (PMN) proportion to diagnose CYTO at AI; (3) to assess the prevalence of CYTO at AI; and (4) to evaluate the effect of CYTO on the pregnancy outcome of that AI. The investigation was performed using 1,625 AI-CT samples harvested from 873 Holstein-Friesian cows from 18 dairy farms in the Flemish region of Belgium. The CT device consisted of adapting a 1.5-cm piece of paper tape on the top of a conventional AI catheter covered with a double guard sheet, allowing an endometrial cytology sample to be taken when performing an AI. A receiving operator characteristic curve was built to assess the threshold level above which the PMN proportion significantly affected the AI success. Multilevel generalized mixed-effect models were built to identify factors affecting the pregnancy outcome of the AI under investigation. Only 7 samples (0.4%) harvested in 5 cows were discarded because of low-quality parameters. The cutoff point for CYTO at AI was set at ≥1% PMN (sensitivity=33.8%, specificity=88.6%). Prevalence of CYTO at AI was 27.8%. The conception rate for CYTO-positive samples was 32.7%, whereas it was 47% for CYTO-negative samples. A CYTO-negative AI had 1.8 [odds ratio (OR)] more chances to become pregnant than a CYTO-positive one. Other factors identified as detrimental for the pregnancy outcome were body condition score ≤1.5 (OR=0.6), relative 305-d milk yield (OR=0.9), dystocia (OR=0.3), parity ≥2 (OR=0.7), and warm months of the year. In conclusion, CT is a consolidated technique to diagnose CYTO at AI, PMN 1% is the threshold level to diagnose CYTO at AI, around one-quarter of inseminated uteri suffer from CYTO, and affected uteri having a significantly lower chance to become pregnant from that insemination.

A comparative study of boar semen extenders with different proposed preservation times and their effect on semen quality and fertility

The present study compared the quality characteristics of boar semen diluted with three extenders of different proposed preservation times (short-term, medium-term and long-term). A part of extended semen was used for artificial insemination on the farm (30 sows/extender), while the remaining part was stored for three days (16–18 °C). Stored and used semen was also laboratory assessed at insemination time, on days 1 and 2 after the collection (day 0). The long-term extender was used for a short time, within 2 days from semen collection, with the aim to investigate a possible advantage over the others regarding laboratory or farm fertility indicators at the beginning of the preservation time. Viability, motility, kinetic indicators, morphology and DNA fragmentation were estimated. The results showed reduced viability, higher values for most of the kinetics, and higher immotile spermatozoa from day 1 to day 2 in all extenders; however, the long-term extender was superior compared to the other two on both days. With regard to morphology and chromatin integrity, the percentage of abnormal and fragmented spermatozoa increased on day 2 compared to day 1 for all of the extenders. However, based on the farrowing rate and the number of piglets born alive after the application of conventional artificial insemination within 2 days from semen collection/dilution, it was found that the medium-term diluents were more effective. In conclusion, it seems that the in vivo fertilization process involves more factors than simply the quality of laboratory evaluated sperm indicators, warranting further research.