Artificial Insemination In Dairy Cows Research Articles

Machine learning to identify endometrial biomarkers predictive of pregnancy success following artificial insemination in dairy cows.

The objective was to identify a set of genes whose transcript abundance is predictive of a cow's ability to become pregnant following artificial insemination (AI). Endometrial epithelial cells from the uterine body were collected for RNA sequencing using the cytobrush method from 193 first-service Holstein cows at estrus prior to AI (day 0). A group of 253 first-service cows not used for cytobrush collection were controls. There was no effect of cytobrush collection on pregnancy outcomes at day 30 or 70 or on pregnancy loss between day 30 and 70. There were 2 upregulated and 214 downregulated genes (FDR < 0.05, absolute fold change >2-fold) for cows pregnant at day 30 versus those that were not pregnant. Functional terms overrepresented in the downregulated genes included those related to immune and inflammatory responses. Machine learning for fertility biomarkers with the R package BORUTA resulted in identification of 57 biomarkers that predicted pregnancy outcome at day 30 with an average accuracy of 77%. Thus, machine learning can identify predictive biomarkers of pregnancy in endometrium with high accuracy. Moreover, sampling of endometrial epithelium using the cytobrush can help understand functional characteristics of the endometrium at AI without compromising cow fertility. Functional characteristics of the genes comprising the set of biomarkers is indicative that a major determinant of cow fertility, at least for first insemination after calving, is immune status of the uterus, which, in turn, is likely to reflect the previous history of uterine disease.

THE EFFECT OF INFLUENCE OF EXPERIENCE AND AGE OF THE ARTIFICIAL INSEMI- NATION OFFICER ON THE SUCCESS OF ARTIFICIAL INSEMINATION IN DAIRY COWS

&#x0D; &#x0D; &#x0D; Research on the effect of influence of experience and age of the artificial insemination officer on the success of artificial insemination (AI) in dairy cows has been conducted. This study aims to determine and examine the ef- fect of influence of experience and age of the artificial insemination officer on the success of artificial insemination (AI) in dairy cows. The research was conducted in December 2022–January 2023 in Lembang District, Bandung Barat. The method used is the survey method. The material used was an artificial insemination officer at the Kope- rasi Peternak Sapi Bandung Utara (KPSBU) Lembang. The variables observed to determine AI success are service conception (S/C), conception rate (C/R). The data analysis used in this study is quantitative descriptive analysis and simple correlation analysis. The results showed that the AI officer experience was an average of 19 years and an average age of 39 years. Average S/C value is 1.84 , Average C/R value is 64.50%. The results of a simple correlation analysis showed that the experience and age of the inseminator had no real effect (P&gt;0.05) on the success of AI in dairy cows. It was concluded that the success rate of AI in dairy cattle based on S/C and CR in Lembang District was good, but the experience and age of the artificial insemination officer did not have a significant effect on the success of artificial insemination in dairy cows.&#x0D; &#x0D; &#x0D;

127 Pregnancy improvement following transfer of parthenogenetic embryos after artificial insemination in dairy cows is dependent on interval from calving

127 Pregnancy improvement following transfer of parthenogenetic embryos after artificial insemination in dairy cows is dependent on interval from calving

Investigation of the Effect of Disinfectant and Antioxidant Intrauterine "Anionic Oxygen" Application on Fertility after Artificial Insemination in Dairy Cows

In the study, a total of 30 clinically healthy fertile Holstein cows (aged 3-8 years old; with 500-700 kg average live weight and 28 litres average daily milk) were used in a private dairy farm in Milas district of Muğla province. Randomly selected cows were divided into two groups (control and treatment) (n=15 cows/group) with almost similar body condition scores (BCS) (as all having approximately BCS of 2.75±0.25 units, 1-5 scale). Cows were monitored for natural oestrus, especially during the 2 months postpartum. Control cows (n=15) showing oestrus were inseminated (throughout the 3 consecutive occasions at maximum) by routine AI via recto-vaginal intrauterine route using frozen bull semen (0.25 ml dose; 7.5 x 106 total motile sperm) and thawing at 37 °C for 30 seconds. Inseminations were carried out for 7 months (from December 2021 to June 2022). For the treatment group, the cows were given the antimicrobial agent (UB20 O8®) intrauterine 30 minutes after each AI. The disinfectant dose, given to the corpus uteri region after the AI, was used as a total of 50 ml mixture (40 ml warm saline and 10 ml disinfectant). Throughout the study, animals were routinely given a farm-specific "dairy cow" diet (with 23% protein/concentrated feed). In addition, cows were provided regularly with clean drinking water, shade, and free movement in paddocks. Total pregnancy rates of cows and the 'pregnancy index' (the number of inseminations per pregnancy) of 35-60-day post-insemination as checked via ultrasound examination were analysed statistically by using Chi-Square and Wilcoxon tests. The possible difference between the groups based on pregnancy rate and pregnancy index data was considered significant at the P&amp;lt;0.05 level. According to the results obtained, numerical differences observed due to local treatment after all insemination periods were not statistically significant (P&amp;gt;0.05). Pregnancy rates following the 1st, 2nd, and 3rd inseminations in the treatment and control groups were 60.00% vs. 46.66%, 86.66% vs. 66.66%, and 93.33% vs. 80.00%, respectively. The total pregnancy indexes in the groups were 1.57 (14 pregnancies/22 inseminations; treatment) and 2.25 (12 pregnancies/27 inseminations; control). Briefly, it was observed that the pregnancy rate and pregnancy index in the treatment group were consistently but only numerically higher than those in the control group, indicating that anionic oxygen could be an effective alternative for intrauterine treatment leading to high fertility early postpartum.

Correlation between Gestation Period and The Calf Sex in Dairy Cows

This study aimed to examine the correlation between the gestation period and the sex of calves as the result of artificial insemination in dairy cows reared by smallholder farmers. Purposive sampling was used in this survey study as the research methodology. A total of 45 heads of dairy cows were observed. A statistical t-test and correlation analysis were used to assess the data. The finding revealed that male to female calves had a sex ratio of 44.44% and 55.56%, respectively. The average gestation period of the dam with male calves (284.45 ± 4.82 days) was longer (p<0.05) compared to the gestation period of the dam with female calves (281.12 ± 5.70 days). There was a correlation between the gestation period and the calf sex with a correlation coefficient of 0.311 (P<0.05). In conclusion, the gestation period of dairy cows at smallholder farmers in this study has a low correlation with the sex of calves born.

Morphologic, Steroidogenic, and Transcriptomic Assessment of the Corpus Luteum in Holstein Cows after Spontaneous or Hormone-Induced Ovulation.

There is evidence that replacing the gonadotropin-releasing hormone (GnRH) with porcine luteinizing hormone (pLH) to synchronize ovulation prior to artificial insemination (AI) increased pregnancy per AI in dairy cows without affecting blood progesterone (P4) concentrations. Whether morphologic, steroidogenic, and transcriptomic differences exist among corpora lutea (CL) formed after ovulation induced by GnRH and pLH is unclear. Our main objective, therefore, was to compare CL characteristics between GnRH- and pLH-induced CL. In 24 non-lactating Holstein cows, ovulations were spontaneous (Spont-Ov) or induced with 100 µg GnRH, 25 mg pLH, or 1 mg estradiol benzoate (EB), with CL excised 12 d after ovulation. In pLH- versus GnRH-treated cows, the duration of elevated LH (above baseline) was prolonged (10 versus 6 h, respectively, p < 0.01), but CL dimensions, pixel intensity of CL images, proportions of steroidogenic and non-steroidogenic luteal cells, and mean plasma LH did not significantly differ. Post-ovulation mean plasma P4 (ng/mL) did not differ among Spont-Ov (3.0) pLH (3.1) or GnRH (3.0) cows but were lower in EB cows (2.0). In vitro P4 concentration was greater in luteal explants of pLH-treated cows than in all other groups (combined means, 16.0 vs. 12.3 µg/mL, p < 0.02). Relative abundance of mRNA for oxytocin receptor (OXTR) was 2-fold higher (p < 0.01) in CL of pLH vs. GnRH cows and highest in Spont-Ov CL. In summary, pLH-treated cows had a longer LH peak, and greatest luteal tissue concentrations and in vitro production of P4. We inferred that increased P4 concentrations at the ovarian-uterine level in pLH-treated cows could have promoted embryo development and increased pregnancy per AI.

A Holistic Approach to the Effects of Intrauterine Antimicrobial Therapy on Pregnancy Rate after Artificial Insemination in Dairy Cows

Post-partum (pp) infertility following the artificial insemination (AI) can be a very common (around 50%) phenomenon in high-yielding dairy cows kept under poor management and feeding practices in particular. Even in clinically healthy females, intrauterine antimicrobial therapy (Lugol, Gentamicin, Rifaximin, etc.) may increase the fertility rate especially in those cows with latent (sub-clinical) intrauterine infection. Undoubtedly, modern animal husbandry requires to reduce possible calving losses with microbial origin that can prevent conception to occur and/or even terminate the ongoing pregnancy. In livestock farming/breeding, numerous obstacles (related to either the animal, humans or else) would prevent to achieve ultimate goals (regular reproductive cycle, insemination, pregnancy, calving, milking and dry period) that allow acceptable or minimum level of income (profit). For a sustainable herd health in profitable sectoral activity, individual females have to be in good health that would be achieved by strict rules to provide optimum animal productivity at animal welfare level. In this sense, a heavy physiological load of candidate mothers and their sustainable reproduction and milking requires at first good management and feeding practices. Beyond that, regarding the routine health services including treatment of dairy cows as appropriate, a ‘holistic approach’ is needed for an efficient therapy and speedy pp recovery of milking females. Otherwise, during the critical period, non-pregnant cows in open period may not conceive or peculiar delays in conception may become inevitable. Undoubtedly, in modern practice, holistic approach in farming/breeding animals requires effective management and feeding along with provision of appropriate health services towards meeting animal welfare level (sustainable high milk yield and regular calving annually). These ultimate aims would be easily facilitated by optimum management and good quality feeding, choosing the right individuals (age and breed) and working with dedicated care-takers and experienced Veterinarians. For the latter, provision of health services should incorporate comprehensive factors covering reproductive hormones, major vitamins-minerals and efficient antimicrobials (systemic and/or local) as needed. Finally, numerous profit-limiting factors (climate changes, heat-stress, water and food scarcity, market prices and residual problems) should also be dealt with a great care. Otherwise, undesirable outcomes (ovarian, uterine and mammary disorders) in dairy farming would be inevitable as commonly seen worldwide.

Effect of Breed and Risk Factors Affecting Conception Rate to Artificial Insemination in Dairy Cows of Tullo District Western Haraghe, Ethiopia

Aim This study was conducted using the questionnaire method to assess the effect of breed and factors affecting conception rate on artificial insemination in dairy cows in Tullo district, Western Haraghe, Ethiopia. Methods A follow-up study design was conducted from December 2018 to June 2019 to determine the effect of breed and factors affecting conception rate to artificial insemination in dairy cows, taking breed, age, parity, body condition and timing of insemination as risk factors. The demographic factors were recorded by interviewing the owners. Most of the cows were examined for pregnancy diagnosis by rectal palpation of the genital tract at 60-80-days post-artificial insemination. Results Out of 114 artificially inseminated cows/heifers, 59 became pregnant, giving an overall first service conception rate of 51.8%. Although the breed, age, parity and body condition score did not affect the conception rate significantly, the pregnancy rate was better in the cross-breed (62.5%), in cows of 5-7-years of age (54.6%), in cows of parity 2-3 (59.2%) and in cows of good body condition score (57.7%). The conception rate in cows inseminated at 12-18-hours after the onset of estrus was significantly higher (62.3%) than those inseminated after 18-hours (31.2%) and before 12-hours (52.4%) after the onset of estrus. Therefore, cows with good body condition score (BCS) and artificial insemination (AI) service at 12-18-hours after the onset of estrus are the best choice of selection for obtaining the best result in the first service conception rate to AI in dairy cows/heifers. Conclusion This study reveals that the conception rate was influenced by the time of AI, so awareness should be given to cattle owners, as they should give AI for their cattle at optimum time within 12-18-hours after onset of heat sign.

Comparison of the Results Synchronization with Progesterone Implants and Fixed Time Artificial Insemination in Dairy Cows

Comparison of the Results Synchronization with Progesterone Implants and Fixed Time Artificial Insemination in Dairy Cows

Challenges and Opportunities on Estrus Synchronization and Mass Artificial Insemination in Dairy Cows for Smallholders in Ethiopia

In this paper, the potentials and constraints on estrus synchronization (ES) and artificial insemination (AI) practice for dairy cattle producers were overviewed. Compared to other African countries, Ethiopia has large numbers of dairy cattle population. However, the self-sufficiency in milk production is not yet attained due to the presence of a lot of limitations that hamper the success of ES and mass AI practice in many parts of the country such as improper selection of cows/heifers, inseminating a large number of cows/heifers in one day at a specific place (which creates stress for both AI technicians and female animals), absence of a data recording system, lack of clearly defined share of responsibilities among stakeholders, poor communication and collaboration among stakeholders, lack of motivations and skills of AI technicians, lack of support and readily available inputs, feed shortages, improper heat detection by smallholders and time of insemination, and lower reproductive performances of both indigenous and crossbred cows which consequently contributed to the unsuccessfulness of the technology.

Risk Factors for the Efficiency of Artificial Insemination in Dairy Cows and Economic Impact of Failure of First Service Insemination in and around Haramaya Town, Oromia Region, Eastern Ethiopia.

A cross-sectional study was conducted from November 2019 to May 2020 in and around Haramaya Town to study the risk factors of artificial insemination (AI) in dairy cattle and evaluate the economic impact of failure of first service AI. A questionnaire survey and field follow-up were employed for collecting data from cattle owners and artificial insemination technicians (AITs) who were selected purposively. Out of the 221 inseminated cows and heifers, the overall conception rate was 60.2% (n = 133). The conception rate was statistically different between breed (P=0.019) and insemination time (P=0.049). From a total of 133 conceived cows and heifers, the conception rate was 68 (53.54%) in local breeds and 65 (69.15%) in cross breeds. Parity, age of cows, inseminator experience, and body condition of cows did not create a significant difference in conception rate (P > 0.05). Failure to conceive at their first AI results in an extra cost of 440 ETB per day until conception. Therefore, to increase the conception rate, dairy cows should be inseminated early when they show signs of estrous; the owners of dairy cows should be trained on how to detect estrous signs in dairy cows and AI technicians should also take training in order to improve their skills.

LRH-A3 and HCG increase pregnancy rate during timed artificial insemination in dairy cows.

The objective of this study was to use luteinizing hormone-releasing hormone A3 (LRH-A3) and human chorionic gonadotrophin (HCG) to improve pregnancy rate of dairy cows during timed artificial insemination (TAI). In experiment 1, the TAI process (0d, GnRH, 100μg; 7d, PGF2α, 0.4mg; 56hr, GnRH, 100μg; 16hr, AI) was applied to 160 dairy cows on 50th and 60th days after parturition respectively. In experiment 2, 320 postpartum dairy cows were treated with TAI (Group A), TAI+25μg LRH-A3 (Group B), TAI+1,500IU HCG 5days after AI (Group C), and TAI+25μg LRH-A3+1,500IU HCG 5days after AI (Group D). In experiment 3, endometrial cells were treated with HCG. The results showed that TAI did not affect the pregnancy rate, while LRH-A3 and HCG increased the pregnancy rate of the cow. HCG of 5IU/ml and 10IU/ml increased the expressions of leukemia inhibitory factor but decreased those of interleukin-6, epidermal growth factor and vascular endothelial growth factor in endometrial cells. This study provided a plan for the use of LRH-A3 and HCG to increase pregnancy rate during TAI in dairy cows.

Effect of follicular growth promoters on timed artificial insemination in dairy cows.

Objective. To evaluate the efficiency of equine chorionic gonadotropin (eCG) and follicle stimulating hormone (FSH) on the pregnancy rate of crossbred cows from different body condition score (BCS) in the postpartum period in timed artificial insemination (TAI). Material and methods. The cows were subjected to the same hormone protocol: Day zero (D0), progesterone-release intravaginal device (PRID) and 2 mg estradiol benzoate (EB); D8, withdrawal of PRID, application 0.150 mg of prostaglandin. On D8, the animals were distributed into three treatments: 1 – (TeCG; n = 98) injection of 300 IU eCG; 2 – (TFSH; n = 84) injection of 20 mg of FSH and; 3 – (Control; n = 115) without further treatment. On D9, all animals received 1 mg of EB; D10, TAI of all the cows. After 30 days from TAI, ultrasound diagnosis of pregnancy was performed. Results. Pregnancy rate did not differ among eCG (52.04%), FSH (40.47%), and Control (40.00%) treated cows (p&gt;0.05). In cows with low body condition, the pregnancy rate was higher (p&lt;0.05) for cows treated with eCG (41.46%) when compared to FSH (18.18%) and Control (17.07%) cows. The postpartum interval among treatments was similar (p&gt;0.05) (35–65 or 66–95days). Conclusions. The use of eCG or FSH did not result in an increase in the pregnancy rate when compared to the control treatment; however, eCG improved the pregnancy rate of cows with low body condition scores.

Characterization of Vaginal Microbiota Associated with Pregnancy Outcomes of Artificial Insemination in Dairy Cows.

The profitability of the dairy and beef industries is largely affected by the actually achieved reproductive efficiency. Although a large proportion of cows worldwide are bred by artificial insemination (AI) services, many potential factors affecting the outcome of pregnancy by AI remain to be addressed. In the present study, we investigated the vaginal microbiota by high-throughput sequencing of 16S rRNA gene and analyzed their association with differential pregnancy outcomes (i.e., pregnant vs. nonpregnant) of multiple AI services in dairy cows. Sequencing of the V3-V4 region totally produced 512,046 high-quality sequences that were computationally clustered into 2,584 operational taxonomic units (OTUs). All OTUs were taxonomically assigned to 10 bacterial phyla. There were statistically significant differences among the three AI service times (T1, T2 and T3) with respect to the Shannon index and number of observed OTUs (p < 0.05). Bray-Curtis distance-based PCoA analysis also revealed that T2 group could be significantly distinguished from T1 and T3. However, no significant difference between the pregnant and nonpregnant cows was found in confidence regarding both alpha diversity and beta diversity. These results could help us better understand the possible influence of vaginal microbial community on pregnancy outcomes of AI service in cows.

Association of pregnancy per artificial insemination with gonadotropin-releasing hormone and human chorionic gonadotropin administered during the luteal phase after artificial insemination in dairy cows: A meta-analysis

One strategy for improving fertility in cattle is administration of GnRH or human chorionic gonadotropin (hCG) during the luteal phase, which increases progesterone (P4) secretion and delays luteolysis. To provide an overview of how GnRH or hCG treatment between 4 and 15 d after artificial insemination (AI) improves pregnancy per AI (P/AI) in cows, a meta-analysis was performed on 107 different trials from 52 publications. Data from 18,082 treated cows and 18,385 untreated controls were meta-analyzed. The meta-analysis explained the relative risk for P/AI with GnRH or hCG treatment under various circumstances. The results did not show any difference in P/AI between cows treated with hCG and cows treated with GnRH. Compared with no treatment, treatment with GnRH or hCG improved the chances of P/AI in cows with very poor (<30%) and poor (30.1 to 45%) fertility, whereas treatment did not benefit cows with very good fertility (>60.1%). Moreover, treatment with GnRH and hCG improved the chances of P/AI in primiparous cows. The improvement was much better in primiparous cows with very low fertility. Treatment with buserelin at a dose above 10 µg and with hCG at a dose above 2,500 IU was associated with increased chances of P/AI compared with lower doses. Treatment with GnRH 10 d after AI was also associated with increased chances of P/AI compared with earlier treatment. The present meta-analysis showed that the use of GnRH and hCG after AI should be focused on cows expected to have low or moderate fertility. Day and dose of treatment have to be considered as well.

Hyperketolactia occurrence before or after artificial insemination is associated with a decreased pregnancy per artificial insemination in dairy cows

The reproductive parameters of dairy cattle have continuously declined worldwide over the last 50 years. Nutritional imbalances are identified as risk factors for this decrease of reproductive performance. The present paper aims to quantify the decrease in the pregnancy per artificial insemination (P/AI) in the case of high milk ketones before and after AI. A total of 388,731 test-day from the Brittany Milk Recording Program in France from 226,429 cow-lactations were provided for this trial. For each test-day, information about lactation characteristics, date of AI, date of the following calving, and acetone and β-hydroxybutyrate (BHB) values were included. Ketones were predicted by Fourier transform mid-infrared spectroscopy using MilkoScan Foss analyzers (Foss, Hillerød, Denmark). Many thresholds were evaluated to define cows with hyperketolactia. Hyperketolactia statuses were then categorized into 1 of 4 possible classes according to the milk ketone dynamics for each AI and each threshold of acetone or BHB values (low-low, high-low, low-high, and high-high) within 20 d before and after AI. Similarly, the dynamics of udder health were characterized by changes in somatic cell counts measured at the same test day as ketone bodies. A logistic regression with a Poisson correction was performed to explain the relationship of P/AI with milk ketones and somatic cell count dynamics. Predicted acetone and BHB ranged from -0.51 to 4.92 mM (mean = 0.08 mM, SD = 0.10 mM) and -0.62 to 5.85 mM (mean = 0.07 mM, SD = 0.1 mM), respectively. Hyperketolactia defined by high acetone levels before AI was not associated with decreased P/AI, but high acetone levels after AI were associated with a >10% reduction in P/AI for all thresholds >0.10 mM. Hyperketolactia, defined by high BHB values before, after, or before and after AI, was associated with a 6 to 14% reduction in P/AI compared with cows with low BHB values. These associations are lower than those reported in previous trials in which blood ketones were used. High ketones in advanced lactation are likely to be the result of various primary disorders (secondary ketosis). Because the present work demonstrated that this situation is considered a risk factor for deteriorated reproductive performance, we suggest that high ketones in early and advanced lactation should be of interest to farm advisors.

Presence of gammaherpesvirus BoHV-4 in endometrial cytology samples is not associated with subclinical endometritis diagnosed at artificial insemination in dairy cows

In the past, bovine herpesvirus 4 (BoHV-4) has been suggested to be associated with metritis and endometritis. However, not many field studies investigated the association between BoHV-4 and subclinical endometritis (SCE). In the present study, the association between the intrauterine presence of BoHV-4 and SCE diagnosed during artificial insemination (AI) was examined on two dairy farms in Belgium. An immunoperoxidase monolayer assay (IPMA) and an enzyme-linked immuno sorbent assay (ELISA) were used to screen the serum for anti-BoHV-4 antibodies. A SYBR green based one step real time qPCR was used to detect and quantify BoHV-4 (ORF20) in nasal, uterine and vaginal samples collected at AI. A reverse transcription qPCR (RT-qPCR) was used to detect mRNA (gB) as proof of a productive BoHV-4 infection. BoHV-4 was detected in 39.4% (farm A)/23.8% (farm B) of the nasal samples, 48.5% (farm A)/19.0% (farm B) of the uterine samples and 51.5% (farm A)/42.9% (farm B) of the vaginal samples. Active replication was only detected in farm A in 38.5% of the BoHV-4 positive nasal samples and in 5.9% positive cases of the vaginal samples. The prevalence of SCE diagnosed at AI was 45.5% and 42.9% in farm A and farm B, respectively. The presence of SCE was associated with a reduced pregnancy outcome at artificial insemination (AI) (P＜0.001). The occurrence of SCE at AI was not associated with the presence of latent or productive BoHV4 infections in the uterus nor in the vagina and nose (P＞0.05).

Incidence of clinical form of anestrus after unsuccessful service in cows in eight dairy herds in north-east of Poland.

There is no information available about the incidence of anestrus and its clinical forms after service in dairy cows in Poland. Thus, the aim of this study was to investigate the incidence of clinical forms of anoestrus after unsuccessful artificial insemination in dairy cows based on ultrasound examination. The study was carried out on 1543 Polish Holstein-Friesian cows in 8 dairy herds in north-east Poland over a three-year period. Cows were examined for pregnancy on day 35 after AI using a Honda 1500 portable ultrasound scanner equipped with a 5 MHz linear-array transducer. Cows diagnosed as pregnant were re-examined on day 45. Of the 1543 inseminated cows, 408 (26.4%) showed no estrus signs and were diagnosed not-pregnant by ultrasonography, 328 (21.3%) returned to estrus within 35 days, and 807 (52.3%) were pregnant via artificial insemination. The incidence of anestrus after service in non-pregnant cows varied among herds from 10.3% to 32.9% of cows (p0.05). Based on ultrasound examination silent heat was diagnosed in 324 (79.4%), corpus luteum pseudograviditatis in 36 (8.8%), ovarian cysts in 26 (6.4%), and ovarian afunction in 22 (5.4%) of 408 anestrous, non-pregnant cows. The results of this study showed that the incidence of anestrus after service in dairy herds in North-East Poland was high. The most prevalent clinical form of post-service anestrus was silent heat.

Risk factors associated with cytological endometritis diagnosed at artificial insemination in dairy cows

In this study, we aimed to determine risk factors associated with cytological endometritis (CYTO) diagnosed at artificial insemination (AI) in dairy cows. The CYTO risk factors were evaluated based on 1.625 AI-CYTO samples obtained from 873 Holstein-Friesian cows from in total 18 dairy herds in Flanders (Belgium). The endometrial cytology samples were obtained using the cytotape technique, which consisted of adapting a 1.5 cm piece of paper tape to a standardly loaded AI catheter, covered with a double guard sheet. The polymorphonuclear cells' (PMNs) cut-off point for CYTO at AI was set at ≥ 1%. We constructed multilevel generalized mixed effect models in order to identify the risk factors associated with the presence of CYTO at AI. The CYTO prevalence at AI was 27.8% at the animal level, while the within-herd level prevalence ranged from 10.7 to 39.7%, with an average of 28.1%. Risk factors associated with the occurrence of CYTO were parity ≥2 [odds ratio (OR) = 1.8], days in milk (DIM) at AI ≥ 124 (OR = 0.4), and warm months of the year [July (OR = 2.9), August (OR = 2.3), and September (OR = 1.4)]. In conclusion, the present study supports that multiparous cows and cows that are inseminated in the summer months have a higher risk to suffer from CYTO at insemination, while the risk for CYTO is lower when the insemination is taking place at ≥ 124 DIM.

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.