Timed Artificial Insemination Research Articles

Ovarian function and pregnancy rates in dairy goats that received 300 IU of human chorionic gonadotropin (hCG) intravaginally at the time of artificial insemination

Two experiments were carried out to evaluate the effects of administering 300 IU hCG intravaginally (i.vag.) at the time of artificial insemination (AI) on ovulatory response, luteal function and pregnancy rates in cyclic Alpine (A) and Saanen (S) goats. All animals received two i.m. injections of 37.5 μg of d-cloprostenol (Prolise®; Tecnopec, São Paulo, SP, Brazil) at 11.5-day (Experiments 1 and 2) or 7.5-day intervals (Experiment 2). One day after the onset of estrus (day of AI=D0), the goats were randomly allocated to one of the two groups that received: 300 IU hCG (Vetecor®; Hertape-Calier, São Paulo, SP, Brazil) i.vag. (G-hCG; Experiment 1: n = 12 A; Experiment 2: n = 80 A + 63 S) or 0.3 mL or saline solution i.vag. (G-Control; Experiment 1: n = 12 A; Experiment 2: n = 82 A + 65 S). Blood samples for measurements of circulating progesterone concentrations were drawn on both days of d-cloprostenol injections and on D3, D7, D10, D13 and D21 (Experiment 1). Transrectal ovarian ultrasonography was done on D7, D10, D13, D17 and D21 (Experiment 1), and pregnancy detection was performed on D60 (Experiment 2). In Experiment 1, there were no differences (P > 0.05) in the mean diameter of ovulatory follicles, timing and number of ovulations, and incidence of early luteal regression between the two groups of goats. However, the total luteal area on D17 and D21 and luteal vascularization on D10 and D13 were higher (P < 0.05) in G-hCG compared with G-Control does. In Experiment 2, the pregnancy rate was higher (P < 0.05) in G-hCG compared with G-Control goats (80.4% compared with 67.3%, respectively). Human chorionic gonadotropin (300 IU) given i.vag. at the time of AI did not alter ovulatory response or progesterone secretory ability of resultant corpora lutea nor did it completely prevent premature luteal regression, but it increased the luteal area and luteal vascularization as well as the conception rate in dairy goats (the latter by 13.1%).

Effects of estradiol cypionate dosage and body condition on reproductive performance of Nellore cattle synchronized for timed-artificial insemination

This experiment was designed to evaluate the effects of increasing doses of estradiol cypionate (ECP) and different body condition score (BCS) on reproductive performance of Bos indicus beef females assigned to a timed-artificial insemination (TAI) management. In this experiment, 1683 Bos indicus Nellore cows were blocked by parity and assigned to receive 1) an intravaginal P4 device (1.9 g of P4) and 2.0 mg of estradiol benzoate on day −11, 12.5 mg (i.m.) of dinoprost tromethamine, 300 IU (i.m.) of equine chorionic gonadotrophin, 0.6 mg (i.m.) of estradiol cypionate and CIDR withdrawal on day −2, followed by TAI on day 0 (n = 849; 0.6ECP) or 2) the same synchronization protocol with 1.0 mg of ECP on day −2 (n = 834; 1.0ECP). In both treatments, estrus expression was measured between days −2 and 0. Body condition score (BCS) was evaluated on days −11, 31, and 71 of the experiment and the BCS variation (Δ) was also determined between these timepoints. Transrectal ultrasonography was performed on days 31, 71, and 111 for pregnancy rate determination. All binary data were analyzed using cow as the experimental unit with GLIMMIX, whereas continuous variables were analyzed with the MIXED procedure of SAS. No treatment effects were observed on estrus expression rate. Treatment × BCS interactions were observed for pregnancy rates in all time points (days 31, 71, and 111), as 1.0ECP cows with a LOW BCS also had a greater P/AI than cows assigned to 0.6ECP. In summary, increasing the dose of ECP benefited the reproductive performance of Nellore beef cows with a reduced BCS (≤2.75), whereas no benefits were seen when the BCS was considered adequate (>2.75).

Vaginal and vestibular electrical resistance as an alternative marker for optimum timing of artificial insemination with liquid-stored and frozen-thawed spermatozoa in sows

Development of a pen-side test to objectively determine the ideal time for artificial insemination (AI) in the sow would save producers time and money. Current processes rely on identification of oestrus via subjective behavioural and physiological markers that are indicative of high blood oestrogen concentrations. This study attempted to use measurements of electrical resistance (ER) in the cervical mucus to pinpoint timing of AI accurately enough to lead to equivalent pregnancy rates as a natural mating. Thirty-six sows were divided into 3 groups and observed for signs of oestrus. Seven sows did not show any oestrus behaviour and were excluded from the study. The remaining 29 sows were inseminated via natural mating and conventional oestrus detection (n = 14), or inseminated artificially with either liquid-stored semen (n = 8) or frozen-thawed semen (n = 7) according to timing indicated from electrical resistance measurements in the vagina and vestibule. Sows that were artificially inseminated on the basis of the electrical resistance readings had a lower pregnancy rate (P = 0.034) and less piglets born alive per litter (P < 0.05) than those that were naturally mated according to a conventional oestrus detection regime. However, the pregnancy rate and total piglets born alive did not differ between the two groups that underwent artificial insemination. Change in electrical resistance in the vagina has the potential to accurately predict ovulation timing, but more work is required to refine the timing of AI in relation to the readings before the technique can be adopted by industry.

Artificial Insemination Pregnancy Program as a Type of Service and Level of Efficiency of Health Services

The purpose of this study is to look at the artificial insemination pregnancy program service as one of the services at Mutiara Bunda Mother and Child Hospital. In this context, it will also look at the perspective of its management efficiency. The pregnancy program with this method involves the age of female and male patients, endometrial thickness (EMT), post-washing total motile sperm count (PTMC), artificial insemination time, insemination frequency, and ovarian stimulation protocol which are compared between the pregnant group and the non-pregnant group to see any correlation. Then, hospital efficiency reflects the ratio of the value of health services provided, both quantity and quality of care to the resources used in health services. This study was conducted at Mutiara Bunda Mother and Child Hospital Padang. The results of the study state that procedurally and institutionally, the pregnancy program service with artificial insemination at RSIA Mutiara Bunda Padang is very good. Specialist doctors and other paramedics are well qualified to implement this service program. The Director of the Mother and Child Hospital includes effective leadership because the performance of staff or officers at the Mother and Child Hospital has worked well, with the motivation provided by the leadership. The hospital has adequate specialist doctors, both in terms of number and type of specialization in accordance with hospital specifications, namely Obgyn and Pediatric specialists. The artificial Insemination Pregnancy Program as a type of service is the first in Padang

Effect of delayed timing of artificial insemination with sex-sorted semen on pregnancy per artificial insemination in synchronized dairy heifers managed in a seasonal-calving pasture-based system

The objective of this study was to evaluate the timing of artificial insemination (AI) with frozen-thawed sex-sorted semen on pregnancy per AI (P/AI) in dairy heifers. A 6-d progesterone Co-Synch protocol was used for ovulation synchronization of dairy heifers, with timed AI (TAI) coincident with (TAI-0) or 8 h (TAI-8) after the second injection of GnRH, corresponding to either 48 h or 56 h after removal of the progesterone-releasing intravaginal device. Pregnancy diagnosis was conducted by transrectal ultrasound scanning of the uterus 34 d after TAI (n = 816 records available for analysis). Generalized linear mixed models were used to examine the effects of treatment on P/AI. Treatment (n = 2), herd (n = 11), and treatment × herd were included as categorical fixed effects. Heifer body weight and Economic Breeding Index values for milk production, fertility, calving performance, beef carcass, cow maintenance, cow management, and health were included as continuous fixed effects. Heifer ID was included as a random effect. Pregnancy per AI was greater for TAI-8 heifers (59%) compared with TAI-0 heifers (50%). Pregnancy per AI ranged from 38% to 75% between herds but there was no treatment × herd interaction. The fertility subindex (positive) and the cow management subindex (negative) were the only continuous animal variables associated with P/AI. Delaying the timing of AI with frozen-thawed sex-sorted semen by 8 h in dairy heifers enrolled on a 6-d progesterone Co-Synch protocol improved P/AI.

Effect of reproductive management programs that prioritized artificial insemination at detected estrus or timed artificial insemination on the reproductive performance of primiparous Holstein cows of different genetic merit for fertility

Our objective was to compare reproductive outcomes of primiparous lactating Holstein cows of different genetic merit for fertility submitted for insemination with management programs that prioritized artificial insemination (AI) at detected estrus (AIE) or timed AI (TAI). Moreover, we aimed to determine whether subgroups of cows with different fertility potential would present a distinct response to the reproductive management strategies compared. Lactating primiparous Holstein cows (n = 6 commercial farms) were stratified into high (Hi-Fert), medium (Med-Fert), and low (Lo-Fert) genetic fertility groups (FG) based on a Reproduction Index value calculated from multiple genomic-enhanced predicted transmitting abilities. Within herd and FG, cows were randomly assigned either to a program that prioritized TAI and had an extended voluntary waiting period (P-TAI; n = 1,338) or another that prioritized AIE (P-AIE; n = 1,416) and used TAI for cows, not AIE. Cows in P-TAI received first service by TAI at 84 ± 3 d in milk (DIM) after a Double-Ovsynch protocol, were AIE if detected in estrus after a previous AI, and received TAI after an Ovsynch-56 protocol at 35 ± 3 d after a previous AI if a corpus luteum (CL) was visualized at nonpregnancy diagnosis (NPD) 32 ± 3 d after AI. Cows with no CL visualized at NPD received TAI at 42 ± 3 d after AI after an Ovsynch-56 protocol with progesterone supplementation (P4-Ovsynch). Cows in P-AIE were eligible for AIE after a PGF2α treatment at 53 ± 3 DIM and after a previous AI. Cows not AIE by 74 ± 3 DIM or by NPD 32 ± 3 d after AI received P4-Ovsynch for TAI at 74 ± 3 DIM or 42 ± 3 d after AI. Binary data were analyzed with logistic regression, count data with Poisson regression, continuous data by ANOVA, and time to event data by Cox's proportional hazard regression. Pregnancy per AI (P/AI) to first service was greater for cows in the Hi-Fert (59.8%) than the Med-Fert (53.6%) and Lo-Fert (47.7%) groups, and for the P-TAI (58.7%) than the P-AIE (48.7%) treatment. Overall, P/AI for all second and subsequent AI combined did not differ by treatment (P-TAI = 45.2%; P-AIE = 44.5%) or FG (Hi-Fert = 46.1%; Med-Fert = 46.0%; Lo-Fert = 42.4%). The hazard of pregnancy after calving was greater for the P-AIE than the P-TAI treatment [hazard ratio (HR) = 1.27, 95% CI: 1.17 to 1.37)], and for the Hi-Fert than the Med-Fert (HR = 1.16, 95% CI: 1.05 to 1.28) and Lo-Fert (HR = 1.34, 95% CI: 1.20 to 1.49) groups. More cows in the Hi-Fert (91.2%) than the Med-Fert (88.4%) and Lo-Fert (85.8%) groups were pregnant at 200 DIM. Within FG, the hazard of pregnancy was greater for the P-AIE than the P-TAI treatment for the Hi-Fert (HR = 1.41, 95% CI: 1.22 to 1.64) and Med-Fert (HR = 1.28, 95% CI: 1.12 to 1.46) groups but not for the Lo-Fert group (HR = 1.13, 95% CI: 0.98 to 1.31). We conclude that primiparous Holstein cows of superior genetic merit for fertility had better reproductive performance than cows of inferior genetic merit for fertility, regardless of the type of reproductive management used. In addition, the effect of programs that prioritized AIE or TAI on reproductive performance for cows of superior or inferior genetic merit for fertility depended on the outcomes evaluated. Thus, programs that prioritize AIE or TAI could be used to affect certain outcomes of reproductive performance or management.

Effect of reproductive management programs that prioritized artificial insemination at detected estrus or timed artificial insemination on the economic performance of primiparous Holstein cows of different genetic merit for fertility

The objective of this randomized controlled experiment was to evaluate the effect of reproductive management programs that prioritized artificial insemination (AI) at detected estrus (AIE) or timed AI (TAI) during the first lactation on the economic performance of dairy cows of different genomically enhanced predicted transmitting ability for fertility. Lactating primiparous Holstein cows from 6 commercial farms were stratified into high, medium, and low fertility groups based on a reproduction index value calculated from multiple genomically enhanced predicted transmitting abilities to predict the number of days to achieve pregnancy. Within herd and fertility group, cows were randomly assigned either to a program that prioritized AIE (P-AIE; n = 1,416) and used TAI for cows not AIE for all AI services or another that prioritized TAI and had an extended voluntary waiting period for first service and prioritized TAI for second and greater AI services (P-TAI; n = 1,338). Cash flow (CF) per cow accumulated for the experimental (first) and second calving interval (CIN) and cash flow per slot per 28 mo after calving in the experimental lactation were calculated. Market and rearing heifer cost values were used for estimating CF. For cows in the high fertility group, a positive effect of delayed pregnancy on milk income during the first lactation was observed (+$248 for P-TAI) but was insufficient to generate significant differences in CF between treatments mainly because of milk income compensation in the second lactation (+$125 for P-AIE) and minor reductions in reproductive cost and gains in calf value for the P-AIE treatment. In this regard, CF for 2 CIN was greater for the P-TAI treatment by $61 and $86 for market and rearing replacement heifer cost, respectively. Similarly, CF per slot was favorable to the P-TAI treatment but only by $13 and $47 for market and rearing replacement heifer cost, respectively. For cows in the low fertility group, CF was numerically in favor of the P-AIE treatment due to a pregnancy and herd exit dynamics that resulted in gains in milk income over feed cost during the first ($29) and second ($113) lactation. Differences in CF for the 2 CIN were $58 and $47 for market or rearing heifer value, respectively, and $77 and $19 for market and rearing heifer values, respectively for the slot analysis. Differences in CF between cows of different genetic merit for fertility were consistent across treatment and estimation method. Of note, cows in the low fertility group had greater CF than cows in the high fertility group in all comparisons, ranging from $198 per cow for 2 CIN to as much as $427 per slot. For the low fertility group, greater milk production contributed directly (milk income over feed cost) and indirectly (reduced culling) to increased CF. We concluded that genetic merit for fertility and CF are associated because cows of inferior genetic potential for fertility had greater CF than cows of superior genetic for fertility despite some increased costs and reduced revenues. Also, the magnitude of the CF differences observed for cows of different genetic merit for fertility managed with the P-AIE or P-TAI program may be valuable to commercial dairy farms but did not allow to conclusively support the choice of a type of reproductive management strategy for cows of different genetic merit for fertility.

Effects of estradiol, progesterone and kisspeptin-1 concentrations at the time of insemination on conception rates in cattle

The present study aimed to investigate the effects of kisspeptin (Kiss-1), estradiol (E2), and progesterone (P4) levels at the time of artificial insemination (AI) on conception rates and also whether or not there is a relationship between Kiss-1 and E2 levels in cattle. Cows (n=100) raised on a semi-closed farm system and having corpus luteum were administered 25mg of prostaglandin F2a (Dinolytic®, Zoetis, Spain) and were evaluated following injection for signs of estrus. Just prior to AI, pre-ovulatory follicle diameters were assessed by ultrasonography (USG) and recorded. Then blood samples were collected. Blood serum samples were separated and stored until analyzed. Pregnancies were determined with rectal USG on day 30±2 following AI. The mean follicular diameters at the time of AI were similar in pregnant (17.9±0.01 mm) and non-pregnant (17.9±0.01 mm) cows. E2, P4, and Kiss-1 levels at the time of AI were determined from serum samples using the ELISA method. The Kiss-1 level at the time of AI in pregnant cows (80.58±4.4 pg/mL) was statistically higher than that in non-pregnant cows (66.68±2.48 pg/mL) (P=0.003). There were no statistically significant differences in E2 and P4 levels between pregnant and non-pregnant cows. Moreover, while a significant correlation was found between serum kiss-1 level and follicle diameter, no significant correlation was found between serum estrogen and progesterone levels. In conclusion, Kiss-1 levels at the time of AI may be used to predict the possibility of successful pregnancy in cattle, allowing different approaches to be developed to increase pregnancy rates in animals with low Kiss-1 levels at the time of AI.

The Role of Certain Specific Hormonal Treatments in Estrus Synchronization of Ewes: A mini Review

Reproductive function is the cornerstone in achieving better profitability for sheep; researchers have developed several ways to guide the reproduction of ewes and develop their reproductive efficiency by its needs. This contributed to reducing the vaccination season and the timing of births in ewes during a limited year to provide optimal care conditions. The optimal use of these techniques in the reproductive function enables us to enter estrus, increase the ovulation rate, and the appropriate timing of artificial insemination, which in turn increases the reproductive efficiency of ewes. Therefore, it has become necessary to use modern biotechnologies such as estrus synchronization technology, which is one of the technologies that help reduce the time and effort required to detect estrus by collecting estrus cases in treated animals. By applying reproductive care programs such as synchronizing estrus and increasing fertility using compounds such as injections of human chorionic gonadotropin, gonadotropin-releasing hormone or progesterone after mating and prostaglandin F2alpha, prostaglandin E and melatonin hormone, it may help to be performed at a specific time

Effect of melatonin implantation prior to ovsynch plus cidr protocol on subsequent ovarian activity and pregnancy rate in summer anestrous Murrah buffaloes

For assessing the impact of melatonin pre-treatment in summer anestrous Murrah buffaloes on subsequent reproductive activity of a fixed time artificial insemination (FTAI) protocol, 83 anestrous Murrah buffaloes were subcutaneously inserted 2x4 mm size absorbable melatonin (MT) implants (18 mg/50 kg b wt) at the base of left ear and 38 Murrah buffaloes were used as non-implanted controls. On day 35 post-MT, the treatment and control group Murrah buffaloes were subjected to FTAI protocol (Ovsynch plus CIDR). Ovarian ultrasonography and jugular vein blood sampling was carried out on day 7 and 10 of protocol and on day 7-post AI. Overall pregnancy rate on day 90 post-AI in MT group was higher compared to control group (55.4 vs 31.6%, P&lt;0.05), along with the higher (P&gt;0.05) plasma progesterone on day 7 of FTAI protocol in Murrah buffaloes of the former group which conceived subsequently compared to their non-pregnant counterparts. Moreover, MT group had higher (P&gt;0.05) increase in dominant follicle diameter between day 7 and 10 of protocol compared to control group. On day 7 post-AI, the luteal profile in pregnant murrah buffaloes of MT group was better (P&lt;0.05) compared to their counterparts in control group (CL: 14.80±0.70 vs 10.82±0.46 mm, P4: 1.54±0.07 vs 1.04±0.08 ng/ml). In conclusion, melatonin pre-treatment in summer anestrous Murrah buffaloes could be associated with better luteal activity and higher pregnancy rate in the Ovsynch+CIDR protocol.

Выбор оптимального времени и методы искусственного осеменения собак

We collected, analyzed, and summarized information on the optimal timing and methods of artificial insemination of dogs at present. Scientific articles published in the bibliographic databases such as e-library, Scopus, and ResearchGate were used for this review. It has been established that artificial insemination has significant advantages over natural insemination, including reliable long-term storage of sperm in cryobanks, the possibility of exporting and importing genetic material without transporting animals, and obtaining offspring from elite male producers from anywhere in the world, even after their death.&#x0D; The time of artificial insemination and natural mating is determined by the date of ovulation using direct (ultrasound visualization of the ovaries) or indirect methods (picture of vaginal smears, multiple measurements of blood progesterone concentration, etc.). In dogs, the egg cell ovulates immature at the stage of the oocyte of the first order. For this reason, it is recommended to inseminate them on the 2nd… 5th days after ovulation, when egg maturation ends in the fallopian tube - the formation of a second-order oocyte.&#x0D; For dog insemination, freshly obtained, diluted chilled, and cryopreserved sperm are used. When using freshly obtained and diluted cooled sperm, the method of choice is an intra-vaginal method of sperm administration, and frozen-thawed sperm requires transcervical intrauterine insemination under video endoscopic control.

GnRH34 with or without estradiol cypionate in timed AI in Bos indicus beef cows

Two experiments were performed to evaluate the effects of GnRH treatment on the fertility of suckled Nelore beef cows treated with an estradiol/progesterone (E2/P4)-based protocol for timed artificial insemination (TAI). Experiment 1 focused on determining the effects of estradiol cypionate (EC) on ovulation in TAI cows treated with GnRH 34 h after removal of the intravaginal P4 device (IPD). Suckled cows (n = 26) were treated with 2 mg estradiol benzoate (EB) and IPD containing 1 g P4. After 8 days, IPDs were removed, and all cows were treated with 150 μg of d-cloprostenol (prostaglandin F2 alpha analog) and 300 IU of equine chorionic gonadotropin (eCG), then separated into two treatment groups consisting of cows who received 1) saline 0.9% i.m. (GnRH34 group) or 2) 0.6 mg i.m. of EC (EC-GnRH34 group). On day 9 (05:00 p.m.), all cows were given GnRH (10.5 μg of buserelin acetate) i.m. No differences were observed between the groups (P > 0.05) in the time of ovulation after IPD removal or in the proportion of cows ovulating. Experiment 2 focused on determining the effects of GnRH34 along with or in the absence of EC on day 8 on pregnancy per AI (P/AI) in postpartum beef cows. Cows (n = 981) were treated similarly to those in Experiment 1, but an additional group, the EC-GnRH48 group, was included, in which cows received EC on day 8 whereas those that did not show estrus received GnRH at TAI. Thus, in this experiment, groups consisted of GnRH34 (n = 322), EC-GnRH34 (n = 335), and EC-GnRH48 (n = 324). A higher rate of estrus expression was observed in cows treated with EC following IPD removal (EC-GnRH34: 69%, EC-GnRH48: 64.8%) than in cows in the GnRH34 group (45.6%). No difference in P/AI was observed between the treatment groups (P = 0.45), but P/AI in cows in the EC-GnRH34 group (64.2%) tended to be greater (P = 0.1) than in cows in the GnRH34 group (58%). In summary, although ovulation synchrony did not differ among the groups, P/AI in cows treated with EC and GnRH 34 h after IPD removal tended to be greater than in cows treated solely with GnRH; this was most likely due to a shorter proestrus/estrus period, considering the lower proportion of cows that displayed estrus in the GnRH34 group. Finally, given that P/AI did not differ between the EC-GnRH34 and EC-GnRH48 groups, our results suggest that, for cows not displaying estrus, administration of EC at the time of IPD removal followed by treatment with GnRH 48 h afterward represents the most cost-efficient TAI strategy for South American Zebu-based beef operations.

Efficient evaluation of photodynamic therapy on tumor based on deep learning

Photodynamic therapy (PDT) is a non-invasive treatment method for treating tumors. Under laser irradiation, photosensitizers in tumor tissues generate biotoxic reactive oxygen, which can kill tumor cells. The traditional live/dead staining method of evaluating the cell mortality caused by PDT mainly depends on manual counting, which is time-consuming and relies on dye quality. In this paper, we have constructed a dataset of cells after PDT treatment and trained the cell detection model YOLOv3 to count both the dead and live cells. YOLO is a real time AI object detection algorithm. The achieved results demonstrate that the proposed method has a good performance in cell detection, with a mean average precision (mAP) of 94% for live cells and 71.3% for dead cells. This approach can efficiently evaluate the effectiveness of PDT treatment, thus speeding up treatment development effectively.

Timed artificial insemination protocols in dairy cattle: Functioning, shortcomings, and improvements

Oestrus detection is currently at the top of the factors limiting the success of artificial insemination in dairy herds. This limitation becomes more pronounced as milk production increases because of higher metabolic clearance rates of steroid hormones leading to low circulating oestradiol concentration near oestrus. The standard OvSynch has overcome this problem by enabling fixed-time artificial insemination, for it synchronises follicular wave emergence, luteolysis, and ovulation. However, it did not improve fertility compared to cycles with spontaneous ovulation, which motivated the development of “fertility programs”. These later are nothing but improved OvSynch protocol. This article explains what went wrong with the original OvSynch protocol, discusses the improvements made by “fertility programs”, and highlights the advantages and limits of the newly tested molecules.

Time of insemination in relation to pregnancy rates in beef cattle after oestrus detection with automated activity monitoring system

BackgroundThe timing of artificial insemination is critical to achieve acceptable results in cattle production systems. Over the past 60 years the length and expression of oestrus in dairy cattle has altered. Recent studies have indicated the optimal timing for insemination after the commencement of oestrus may now be earlier than traditional recommendations in beef cattle, as is the case in dairy cattle. The aim of the current study was to evaluate the effect of time from onset of oestrus [as determined by an automated activity monitoring system (AAMS)] to artificial insemination (AI) on pregnancy outcome in Norwegian beef cattle. Five commercial beef suckler herds participated in a cohort study by providing data on the time of AAMS alarm and time of AI. Blood sampling on the day of AI was performed and serum progesterone concentration measured. Pregnancy detection was performed by transrectal ultrasonography and aging of the fetus performed when necessary. A mixed logistic regression model was fitted to study the effect of time from AAMS alarm to AI on pregnancy outcome. Time categories used in the model were < 12 h, 12–24 h, and > 24 h.ResultsAI periods (n = 229) with serum progesterone concentration < 1 ng/mL were available for analysis. Overall pregnancy risk per AI for the whole study period was 65.5%, with an inter-herd variation from 10 to 91%. Median time elapsed from AAMS alarm to AI was 17.75 h. Herd affected pregnancy outcome (P = 0.001), while breed and parity status (heifer/cow) did not. The time category closer to AAMS alarm 0–12 h showed a numerically lower pregnancy risk as compared to the baseline group which had AI 12–24 h after onset of oestrus.ConclusionThis study found no evidence to support a change in the recommended timing of AI in beef suckler cows.

Perspective: Can early embryonic losses be reduced in lactating dairy cows?

Perspective: Can early embryonic losses be reduced in lactating dairy cows?

The effect of co-supplementation of fish oil and vitamin E on reproductive performance and metabolic profile during the transitional period in dairy cows

The objective of the present study was to determine the effect of oral supplementation of dairy cows with a combination of fish oil and vitamin E (Vit E) from approximately 7 days (d) before the expected calving date up to 21 days postpartum, on their reproductive performance and metabolic profile. Eighty Holstein multiparous cows were randomly assigned into one of two ration groups during the transitional period. The treatment group cows (n=40) received a transitional diet (pre-and post-partum based on the NRC 2001) supplemented with fish oil (FO, 100 g/ once per day +Vit E (8000IU/kg/d); and the control cows (n=40) received the same concentrate without FO. Blood samples were collected at 1 week before the expected calving date, and 1, 2 and 3 weeks postpartum. After a voluntary waiting period, all cows received timed artificial insemination (TAI) at 76-81 days in milk (DIM) following the PresynchOvSynch protocol. Pregnancy diagnosis was performed 30-40 days after TAI using a transrectal ultrasonography. Our results showed that the cows fed the FO+Vit E diet had a statistically higher first service pregnancy rate (46.3 % vs. 39.6%, P&lt;0.001) at 30-40 days after TAI than those fed the control diet. Also, cows that consumed the FO+Vit E treatment diet had lower late embryo loss at 40-70 days post insemination than the control. Plasma concentrations of triglycerides (d7, 14, and 21), cholesterol (d7 and 14), glucose (d14), insulin (d-7) progesterone (d14 and 21) in the treatment group were higher (P&lt;0.05) compared to the cows fed control diets. Non-esterified fatty acid (NEFA) levels were not significantly affected by the dietary treatments pre-partum, while β –hydroxybutirate acids (BHBA) levels on day 21 (P&lt;0.05) were higher in the control group. The results indicated that supplementation of the diet with fatty acid and high doses of vitamin E could improve reproductive performance in dairy cattle.

Association of activity and subsequent fertility of dairy cows after spontaneous estrus or timed artificial insemination

The objective of this observational study was to evaluate the association between increased physical activity at first artificial insemination (AI) and subsequent pregnancy per AI (P/AI) in lactating Holstein cows following spontaneous estrus or a timed AI (TAI) protocol. We also wanted to identify factors associated with the intensity of activity increase (PA) captured by automated activity monitors (AAM) and fertility. Two experiments were conducted, in which cows either were inseminated based on the alert of the AAM system (AAM cows) or received TAI following a 7-d Ovsynch protocol (TAI cows) if not inseminated within a farm-specific period after calving. Experiment 1 included 2,698 AI services from AAM cows and 1,042 AI services from TAI cows equipped with the Smarttag Neck (Nedap Livestock Management) from a dairy farm in Slovakia (farm 1). In the second experiment, 6,517 AI services from AAM cows and 1,226 AI services from TAI cows fitted with Heatime (Heatime Pro; SCR Engineers Ltd.) from 8 dairy farms in Germany (farms 2-9) were included. Pregnancy diagnosis was performed on a weekly basis by transrectal ultrasound (farms 1, 3, 7, 8) or by transrectal palpation (farms 2, 4-6, 9). Estrous intensity was represented by the peak value of the change in activity. In experiment 1, PA was categorized into low (x-factor 0-20) and high (x-factor 21-100) PA, and in experiment 2 into low (activity change = 35-89) and high (activity change = 90-100) PA. In TAI cows from both experiments, PA was additionally categorized into cows with no AAM alert. Data were analyzed separately for AAM and TAI cows using multinomial logistic regression models for PA in TAI cows and logistic regression models for PA in AAM cows and P/AI in both groups. In experiment 1, P/AI of AAM cows was greater for AI services performed with conventional frozen semen (57.6%) compared with sexed semen (47.2%), whereas type of semen only tended to be associated with P/AI in TAI cows (54.4% conventional frozen semen vs. 48.9% sexed semen). In experiment 2, P/AI was greater for fresh semen (AAM cows: 44.4% vs. TAI cows: 44.2%) compared with conventional frozen semen (AAM cows: 37.6% vs. TAI cows: 34.6%). In both experiments, pregnancy outcomes were associated with PA. In experiment 1, AAM cows with high PA (55.1%) had greater P/AI than cows with low PA (49.8%). Within TAI cows, cows with no alert (38.8%) had reduced P/AI compared with cows with low (54.2%) or high PA (61.8%). In experiment 2, AAM cows with high PA (45.8%) had greater P/AI compared with cows with low PA (36.4%). Timed AI cows with no alert (27.4%) had decreased P/AI compared with cows with low (41.1%) or high (50.8%) PA. The greatest risk factors for high PA were parity (experiment 1) and season of AI (except for TAI cows from experiment 1). We conclude that high PA at the time of AI is associated with greater odds of pregnancy for both AAM and TAI cows. In both experiments, about 2 thirds of AAM cows (experiment 1: 69.9% and experiment 2: 70.7%) reached high PA, whereas only approximately one-third or less of TAI cows (experiment 1: 37.3% and experiment 2: 23.6%) showed high PA. Although we observed similar results using 2 different AAM systems for the most part, risk factors for high PA might differ between farms and insemination type (i.e., AAM vs. TAI).

Presynchronization with prostaglandin F2α and gonadotropin-releasing hormone simultaneously improved first-service pregnancy per artificial insemination in lactating Holstein cows compared with Presynch-14 when combined with detection of estrus

This study aimed to determine the effect of 2 simple breeding strategies combining artificial insemination (AI) after detection of estrus (AIED) and timed AI (TAI) on first-service fertility in lactating Holstein cows. Weekly, lactating Holstein cows (n = l,049) between 40 and 46 d in milk (DIM) were randomly assigned to initiate 1 of 2 breeding strategies for first service: Presynch-14 and PG+G. Presynch-14 is a presynchronization strategy with 2 PGF2α treatments 14 d apart with the last PGF2α 14 d before the initiation of the Ovsynch protocol. Cows treated with PG+G receive a simpler presynchronization program that uses PGF2α and GnRH simultaneously 7 d before Ovsynch. In both treatments, cows detected in standing estrus by tail chalk at any time ≥55 DIM were inseminated, and treatment was discontinued (n = 525). Cows completing treatment received TAI from 78 to 84 DIM (n = 526). In a subgroup of cows that received TAI, blood was collected (n = 163) to assess circulating concentrations of progesterone, and ultrasonographic evaluations of ovaries were performed on the day of first GnRH of Ovsynch (n = 162) and PGF2α of Ovsynch (n = 122). The proportion of cows that received TAI was greater for PG+G compared with Presynch-14 (63.5 vs. 31.9%), which increased DIM at first service for cows treated with PG+G compared with Presynch-14 (75.5 ± 0.4 vs. 68.7 ± 0.4). For cows receiving TAI, the ovulatory response to first GnRH of Ovsynch (73.8 vs. 48.8%) and the proportion of cows with functional corpora lutea (92.6 vs. 73.1%) were greater for PG+G than Presynch-14. Cows treated with PG+G had greater overall pregnancy per AI (P/AI) 42 ± 7 d after AI (40.2 vs. 33.6%) and calving per AI (32.1 vs. 25.2%) than Presynch-14. For cows receiving AIED, treatment did not affect P/AI 42 ± 7 d after AI. However, for cows receiving TAI, PG+G increased P/AI compared with Presynch-14 (44.6 vs. 35.2%). Overall, cows receiving TAI had greater P/AI 42 ± 7 d after AI (42.5 vs. 31.5%) and calving per AI (34.1 vs. 23.7%) and decreased pregnancy loss (16.8 vs. 25.2%) than cows receiving AIED. In summary, PG+G increased the proportion of cows receiving TAI and the DIM at first service, P/AI, and calving per AI compared with Presynch-14 when both TAI programs were combined with AIED.

94 Changes in Vaginal Microbiome of Beef Cows Enrolled in an Estrous Synchronization Protocol

Abstract Vaginal pH and microbiome have been reported to influence fertility in women. In cattle, estrous synchronization protocols are a great tool to overcome infertility; however, the effects of the hormones administered in the protocol on vaginal microbiome and pH are unknown. A total of 24 cows were enrolled in the 7-d Co-Synch + controlled internal drug release (CIDR) protocol and had individual vaginal flushes collected during the handling events of the protocol on days 0, 7 and on day 10 at timed-artificial insemination (TAI). Flushes were used for pH analysis and DNA extraction. Extracted DNA was submitted to analysis by whole genome shotgun sequencing. Pregnancy status was assessed by ultrasonography 35 days after TAI. Firmicutes was the most abundant phylum, followed by Proteobacteria, and Actinobacteria for all collection days. Bacteria from the Clostridia genus were the most abundant in all samples. Greater alpha Shannon diversity (within sample diversity) was observed for pregnant animals on day -10 compared with non-pregnant animals at the phylum, class, and order (P &amp;lt; 0.01), as well as family, and genus level (P &amp;lt; 0.001). Overall, Shannon diversity was decreased on day 7 compared with day 0 (P &amp;lt; 0.05 at class and order level; P&amp;lt; 0.01 at genus and family level) and was greater at TAI compared with day 7 (P &amp;lt; 0.01 at the phylum, class, and order level; P &amp;lt; 0.001 at family and genus level). No differences were observed for Shannon diversity between samples from D0 and TAI (P &amp;gt; 0.05). No correlations between Shannon diversity were observed in relation to vaginal pH (P &amp;gt; 0.1). Bray-Curtis analysis (between sample diversity) revealed clustering by day (P &amp;lt; 0.05 at the order, family, and genus level) and a tendency (0.1 &amp;lt; P &amp;lt; 0.05) at the phylum and class level. In conclusion, greater fertility was observed for animals with greater within sample diversity prior to protocol initiation. Furthermore, vaginal bacterial diversity changes throughout the protocol, with decreased diversity observed on day 7 of the protocol, but restored diversity on day0 at TAI.