Next Article in Journal
Government Guidance Fund Empowers the Supply Chain Financing Decision of Marine Ranching Considering Environmental Enrichment and Friendliness
Next Article in Special Issue
MRI Anatomical Investigation of Rabbit Bulbourethral Glands
Previous Article in Journal
Eating Quality of Pork from Entire Male Pigs after Dietary Supplementation with Hydrolysable Tannins
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Animals
Volume 13
Issue 5
10.3390/ani13050896
animals-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Influence of Ovarian Status and Steroid Hormone Concentration on Day of Timed Artificial Insemination (TAI) on the Reproductive Performance of Dairy Cows Inseminated with Sexed Semen

by
Stanimir Yotov
1,*,
Ivan Fasulkov
1,
Anatoli Atanasov
1,
Elena Kistanova
2,
Branimir Sinapov
1,
Boyana Ivanova
1,
Dobri Yarkov
3 and
Darina Zaimova
4
1
Department of Obstetrics, Reproduction and Reproductive Disorders, Trakia University, 6000 Stara Zagora, Bulgaria
2
Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
3
Department of General Livestock Breeding, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria
4
Department of Industrial Business and Entrepreneurship, Faculty of Economics, Trakia University, 6000 Stara Zagora, Bulgaria
*
Author to whom correspondence should be addressed.
Animals 2023, 13(5), 896; https://doi.org/10.3390/ani13050896
Submission received: 5 January 2023 / Revised: 24 January 2023 / Accepted: 28 February 2023 / Published: 1 March 2023
(This article belongs to the Special Issue Intelligent Animal Husbandry)
Browse Figure
Review Reports Versions Notes

Abstract

:

Simple Summary

The use of sexed semen results in a decrease in the number of cows required for progeny testing, the fast production of replacement dairy heifers and a significant reduction in the herd renewal period. Due to some of the disadvantages of sex-sorted semen, such as lower concentration, morphological damage and sperm of lower fertility, there are many problems related to the selection of animals appointed to estrus synchronization programs for artificial insemination with sexed semen. The present study showed a strong relationship between ovarian status, the size of the PF and the estradiol and progesterone concentrations on the day of TAI and the reproductive performance of dairy cows, irrespective of the estrus synchronization treatment used. In this context, the simple and cost-effective ultrasound examination of cows’ ovaries on the day of TAI can be a reliable tool for the selection of candidates for sex-sorted semen application.

Abstract

This study aimed to evaluate the effect of the ovarian status and steroid hormone concentration on the day of TAI on the reproductive performance of dairy cows subjected to estrus synchronization treatment and timed artificial insemination with sexed semen. Seventy-eight cyclic Holstein cows pre-treated with PGF2α-GnRH were divided in two groups—I (Preselect-OvSynch, n = 38) and II (OvSynch+PRID-7-day+eCG, n = 40)—and inseminated with sexed semen. The presence of preovulatory follicle (PF) with or without corpus luteum (CL), the PF diameter, the estradiol (E2) and progesterone (P4) concentrations on the day of TAI, the pregnancy rate (PR) and embryo loss were determined. On the day of TAI, 78.4% of all the pregnant cows presented a PF (mean size 1.80 ± 0.12 cm) without CL, low P4 (0.59 ± 0.28 ng/mL) and high E2 (12.35 ± 2.62 pg/mg) concentrations. The positive correlation between the size of the PF and the level of E2 in the pregnant cows from group II was stronger than that of group I (R = 0.82 vs. R = 0.52, p < 0.05). The pregnancy rate on day 30 (57.5% vs. 36.8%) and day 60 (50% vs. 26.3%; p < 0.05) and the embryo losses (13% vs. 28.5%) showed better effects of treatment in group II. In conclusion, the ovarian status and the steroid hormone concentration on the day of TAI influence the pregnancy rates of dairy cows subjected to estrus synchronization and timed artificial insemination with sexed semen.

1. Introduction

Insemination with sexed semen is an intelligent tool to accelerate herd expansion, minimize waste production, improve animal welfare, increase profitability and reduce greenhouse gas emissions from beef and dairy farming [1,2]. Semen sexing is an assisted reproductive technology that allows the sorting of spermatozoa carrying the X- or Y-chromosome and the production of newborn animals of a precisely defined and preferred sex [3,4]. Its main advantage is the production of more female offspring with valuable genetic traits in a shorter period. The use of sexed semen results in a reduction in the number of cows required for progeny testing, the fast production of replacement dairy heifers and a significant reduction in the herd-renewal period. Accelerated genetic progress and the accomplishment of in-house production of replacement heifers increase the degree of farm biosecurity. In line with modern standards of animal welfare, there is a reduction in difficult births when the sexed semen originates from bulls selected for ease of calving [5,6,7,8].
Despite the aforementioned advantages, the concentration of spermatozoa in sexed semen is lower than in conventional semen, and the sorting procedure usually leads to some morphological damage to the sperm cells as well as reduced mitochondrial activity, which is related to low fertility [9,10,11]. The standard dose of one straw with sexed sperm is approximately 2 × 106 sperm, while the straws with conventional semen contain 15–20 × 106 spermatozoa per dose [12,13]. Sperm cell damage is associated with lower survival in the genital organs of female animals (12–16 h for sexed vs. 24–36 h for conventional semen) and requires excellent heat-detection management [14]. Significantly greater conception rates in heifers than in lactating cows and animals with observed hormonally induced estrus have been determined by different authors [15,16,17,18]. Because of this reduced fertility, most of these authors suggest the application of sexed semen for the insemination of heifers with observed estrus.
Nevertheless, studies about the use of sexed semen in lactating dairy cows are in progress. Maicas et al. [19] report increased pregnancy per artificial insemination (P/AI) in lactating cows when target animals were selected based on base parity, body condition score (BCS), economic breeding index (EBI) and days in milk. In this aspect, DeJarnette et al. [20] recommend artificial insemination with sexed semen mainly in dairy cows with observed estrus, and recommend avoiding the use of a fixed-time insemination, as the success rate was highly variable. In contrast, Karakaya-Bilen et al. [21], comparing three TAI protocols with conventional and sexed semen, conclude that presynchronization increases ovulation and improves the P/AI in cows inseminated with both semen types. According to Darke et al. [22], there is no significant difference in P/AI when cows are inseminated with sexed semen at 16 or 22 h after GnRH treatment, suggesting that 16 to 22 h after GnRH injection probably encompasses the optimal window for the timing of AI with sex-sorted semen. However, Louber et al. [23] underline that cows inseminated with sexed semen 16 h after the Double-Ovsynch program yielded more P/AI than cows inseminated 24 h after the same treatment. The lower result was associated with decreased time for sperm transport and capacitation, as well as differences in the hormonal milieu at critical time points near the end of the synchronization protocol. Guner et al. [24] observed a higher pregnancy rate in cows that expressed estrus following synchronization with progesterone-based OvSynch than cows with no observed estrus. Different studies have reported the influence of estradiol and progesterone concentrations on follicular development, ovulation and the pregnancy rate in cows with natural or synchronized estrus and TAI [25,26,27,28].
Nevertheless, questions remain open regarding the effects of animal selection in synchronization programs and TAI with sexed semen, as well as responses to different hormonal treatments and steroid hormone concentrations at the time of AI on the pregnancy rate.
Inadequate preovulatory concentrations of estradiol in cows around the time of fixed-time insemination was shown to be a reason for lower pregnancy rates associated with improper uterine pH at the time of insemination [29]. A study by Herlihy et al. [26] demonstrated differences in periovulatory E2 concentrations between treatments to synchronize estrus and ovulation. They observed increased periovulatory E2 concentrations with a CIDR-based compared with an OvSynch protocol. Preovulatory concentrations of estradiol probably play a crucial role in pregnancy maintenance, not only directly by regulating uterine gene expression but also indirectly throughout the subsequent estrous cycle [27].
In most mammals, progesterone production by the CL is essential for the establishment and maintenance of pregnancy and the stimulation of the uterine functions that allow early embryonic development, implantation, placentation and successful fetal and placental development to term [30]. According to Cerri et al. [25] reduced concentrations of progesterone before ovulation can modify endometrial gene expression beyond steroid receptors to a variety of other genes that might be essential to early embryonic survival. They determined that cows with lower plasma concentrations of progesterone and greater concentrations of estradiol had larger ovulatory follicle diameters at the end of the synchronization protocol than cows with high progesterone. Baruselli et al. [31] reported the influence of progesterone concentrations during superovulation protocols on follicular growth, oocyte quality and embryo quality, and the need for adjustments to the protocols depending on the animal category and breed.
The aim of the current study was to determine the effect of the ovarian status and steroid hormone concentration on the day of TAI on the reproductive performance of dairy cows subjected to different estrus synchronization treatments and timed artificial insemination with sexed semen.

2. Materials and Methods

2.1. Animals

This study was carried out with 78 clinically healthy Holstein cows reared on a commercial dairy farm in Bulgaria, located at latitude of 42.183 N, longitude 25.567 E. The animals were from first to third lactation, weighing 680–700 kg, ≥63 DIM (range 63 to 120 DIM),with an average daily milk yield ≥ 28 kg (range 28 to 34 kg), and located in a loose housing system with individual boxes and a self-locking feed fence. Their feed was with a total mix ration, and their daily diet comprised corn silage, triticale haylage, straw, beer mash, soybean meal, medium-coarse grain soft wheat, corn grain, mineral and vitamin supplement, natrium chloride and a toxin binder with water intake ad libitum. The investigation was conducted between October and December. All procedures were in agreement with the Bulgarian Veterinary Law (25 January 2011) regarding the living conditions and welfare of livestock animals used for experimental purposes, which is adapted to European Union regulation 86/609 (approval no. 3601/09.12.2020).

2.2. Experimental Design, Hormonal Treatments, Timed Artificial Insemination, Pregnancy Rate and Embryo-Loss Determination

Animal selection was based on ultrasound examination of reproductive organs and ovarian status determination. A transrectal ultrasonography was conducted using ultrasound scanner SonoScape S2 Vet and a multifrequency (7–12 MHz) linear transducer (SonoScape Medical Corporation. Shenzhen, China). Only cows with corpus luteum (CL) and at least one large follicle (≥10 mm in diameter) in one of the ovaries were included in the study. Their follicular diameters were measured using the in-built scale provided with the ultrasound, and in calculation, only the largest was used. The animals were divided into two groups according to the hormonal treatments, as the proportions of animals that were close in terms of days in milk, average milk yield and number of lactations were almost the same. The estrus synchronization protocols were designed to start on day 6–7 of estrous cycle (Figure 1). After animal selection, both groups were subjected to presynchronization treatment, including single intramuscular injection of PGF2α (25 mg dinoprost tromethamine, Enzaprost T®, CEVA Santé Animale, Libourne, France) on the day of the first ultrasound, followed by intramuscular GnRH administration (100 μg gonadorelin as diacetate, Ovarelin®, CEVA Santé Animale, Libourne, France) on the day of heat detection (3rd or 4th day). The heat detection after the prostaglandin injection in the presynchronization treatment was registered by an electronic AfiMilk® system for activity monitoring (AfiMilk, Ltd., Kibbutz Afikim, Israel). Day 7 after the end of the hormonal pre-treatment was accepted as day 0 of estrus synchronization protocol. The first group (group I, n = 38) was treated with Preselect-OvSynch protocol, including 100 μg GnRH on days 0 and 9 and 25 mg PGF2α on day 7. Timed artificial insemination was carried out 20 h after the last GnRH injection. The second group (group II, n = 40) was included in OvSynch+PRID-7-day+eCG protocol. On day 0, a progesterone-releasing intravaginal device (PRID Delta® containing 1.55 g progesterone, CEVA Santé Animale, Libourne, France) was inserted into the vagina and 100 μg GnRH was injected intramuscularly. On day 7, the PRID was removed and each animal received 25 mg PGF2α and 500 UI eCG (equine chorionic gonadotropin; Folligon®, Intervet International B.V., Boxmeer, The Netherlands) followed by a second injection of 100 μg GnRH 56 h later. The artificial insemination was 16 h after the second GnRH administration.
The ovarian status (presence of follicles with or without CL in one of the ovaries and diameter of the preovulatory follicle) was determined by ultrasound immediately before TAI (Figure S1). The largest follicle located in the left or the right ovary was defined as a preovulatory follicle (PF). The timed artificial insemination of all cows was performed using frozen sexed semen in straw from the same bull with a high fertility index. The semen was deposited deep cervically by the same operator. The reproductive performance included registration of pregnancy rate and embryo loss. The pregnancy status (pregnant or non-pregnant cows) was determined by transrectal ultrasonography on days 30 and 60 after the TAI. A positive pregnancy diagnosis was recorded upon observation of an echogenic embryo located in echogenic uterine lumen (Figure S2). Embryo loss was calculated according to the pregnancy results on days 30 and 60 after TAI.

2.3. Measurement of Steroid Hormone Concentrations

Blood samples were collected on day of TAI before the ultrasound examination. The serum from the coagulated blood samples was separated by centrifugation (3000× g for 15 min) and stored in a sterile tube at −20 °C until analysis. Steroid hormone concentrations were measured by an automated quantitative enzyme-linked fluorescent immunoassay (ELFA; VIDAS; ImmunoDiagnostic Assay System, bioMerieux, Craponne, France). For the progesterone (P4) assay, we used a VIDAS® Progesterone kit with an analytical sensitivity of 0.1 ng/mL and imprecision within and between runs of 5.7–3.8% and 6.2–3.8%, respectively. The level of estradiol-17β (E2) was determined using a VIDAS® Estradiol II kit with an analytical sensitivity of 9 pg/mL and imprecision within and between runs of 7.5–3.9% and 9.5–5.1%, respectively. The measurement range of the kit was 9–3000 pg/mL; therefore, the samples with values < 9 pg/mL were counted as zero.

2.4. Statistical Analysis

The results were processed by computer program Statistica version 10.0 (Stat-Soft. Inc. Tulsa, OK, USA). The values of different parameters are presented as mean ± standard deviation (mean ± SD). An analysis of variance for main effects (ANOVA) was used to estimate the statistical significance of the influence of different factors on the likelihood of pregnancy. The strength of the relationship between parameters was assessed by Pearson’s linear correlation test. The significance of the differences between the mean values for different groups and subgroups was compared using the post hoc Tukey’s test or a Chi-squared test for comparison of proportions with small samples. Statistical significance was considered at p < 0.05.

3. Results

At the beginning of the study, the selected animals had corpus luteum, small or medium follicles and at least one large follicle located in one of the ovaries, which was accepted as an indicator of cyclicity. All cows had a positive response after the PGF2α injection of the presychronization treatment, evidenced by the detection of estrus behavior between 3 and 4 days later.
The comparative analysis of the ovarian status showed that in group I, 16.6% more non-pregnant cows had PF with CL on the day of TAI, while of the pregnant animals, 28.6% more had PF without CL. (Table 1). In group II, a significantly higher percentage of PFs without CL on the day of TAI was observed in both the non-pregnant and the pregnant animals (70.6% and 87%; p < 0.05).
The mean diameters of the PFs in the non-pregnant and pregnant cows treated with Preselect-Ovsynch were close (p = 0.12). The value of this parameter in the OvSynch+PRID+eCG group was higher in the pregnant than in the non-pregnant animals (1.88 ± 0.10 mm vs. 1.68 ± 0.19 mm; p < 0.05). The mean PF diameter in the pregnant cows in group II also differed significantly (p < 0.05) from the follicular diameters in the pregnant and non-pregnant cows in group I.
The blood progesterone concentrations on the day of TAI indicated significant (p < 0.05) differences between the pregnant and non-pregnant dairy cows, irrespective of the estrus synchronization protocol used. This was clearly expressed in group I, where the concentration of P4 in the non-pregnant animals exceeded that in the pregnant animals by a few times (Table 1). The lowest level of P4 on the day of TAI was recorded in the pregnant cows from group II. The mean estradiol-17β concentrations in the pregnant and non-pregnant cows in both groups also differed significantly (p < 0.05). The highest level of E2 on the day of TAI was determined in the pregnant animals that received OvSynch+PRID+eCG treatment. It was higher compared to the measured level E2 in the non-pregnant animals in this group (p < 0.05) and the E2 values in the whole group I (Table 1).
The pregnancy rate on day 30 tended to be higher by about 20% in the OvSynch+PRID+eCG- compared to the Preselect-OvSynch-treated cows, but the difference was not significant (p = 0.16). However, on day 60, the PR values were significantly greater in group II compared to group I (Table 1). In addition, the embryo losses were 15.5% lower in the animals treated with protocol II than in those treated with protocol I. The animals with embryo loss in pregnant subgroup I had PF only, and PF and CL on the day of TAI at rates of 25% and 75%, respectively. At the same time, 100% of the cows with embryo loss in the pregnant subgroup II exhibited PF and CL. From a total of seven animals, PF with a Cl was detected in 85.7% of cows, while in 14.3%, this was not observed. The average diameter of the PFs on the day of TAI was 1.76 ± 0.07 mm. The pregnancy reductions of 10.3% in group I and of 7.5% in group II between 30 and 60 days were not statistically significant.
The investigated effects, irrespective of the estrus synchronization treatment used, are presented in Table 2. Comparative analysis showed that overall, the pregnant cows had significantly more cases of PF without CL in the ovaries on the day of TAI. The mean values for the PF diameter and E2 concentration on the day of TAI were higher in the pregnant group than in the non-pregnant group (p < 0.05), whereas the concentration of P4 was lower (Table 2. p < 0.05). A strong correlation was observed between the sizes of the preovulatory follicles and the level of E2 in all the animals (R = 0.93, p < 0.001), as well as in the pregnant animals treated with both synchronization schemes (R = 0.79, p = 0.001). Interestingly, in the pregnant cows from group II, this correlation was stronger compared to that in the pregnant cows from group I (R = 0.82 vs. R = 0.52, p < 0.05). The analysis (Table S1) showed that both the PF size and the E2 concentration were influenced by the ovarian status (p = 0.007) and by the treatment protocol (p = 0.019). The observed power of the effect of pregnancy status on these parameters was the highest (observed power 0.94, p < 0.05).

4. Discussion

The success of the artificial insemination of dairy cows with sexed semen is rather variable and depends on different on-farm factors, the age, BCS and parity of the animals, sire selection, service number, estrus detection management and cow fertility potential [32,33,34]. A reduced number of spermatozoa per dose, the limited lifespan of sorted sperm cells, the insemination of cows with inadequate development of ovulatory follicles, or failed ovulation due to a hormonal imbalance and the performance of artificial insemination at an inappropriate time are the main reasons for low conception rates [35,36,37,38]. In this context, some authors recommend eliminating some of these problems by including dairy cows in estrus synchronization programs with fixed times of artificial insemination [39,40,41]. A major advantage of these programs is the possibility of timed AI, which is less time-consuming, makes work with the animals easier and provides control over ovulation time [42]. Starting the OvSynch treatment between days 5 and 9 of the estrus cycle is associated with a greater probability of having ovulations with a new CL and the development of a new follicular wave. This results in the synchronized ovulation of a newly formed dominant follicle at the end of the synchronization program and better conception rates [43,44]. Different studies reveal a positive effect of progesterone-releasing devices on conception rates after their inclusion in estrus synchronization protocols [21,24,45].
This study presents results regarding the effects of ovarian status and steroid hormone concentrations at the time of TAI on the pregnancy rates of dairy cows treated by Preselect-OvSynch and OvSynch+PRID+eCG estrus synchronization protocols, starting on day 6–7 of the estrous cycle and timed AI with sexed semen from a high-fertility bull. The uniform distribution of the animals in both treatment groups was proven by the fact that the same ovarian status was observed before the start of the experiment, and by the positive response of all the cows to the presynchronizing PGF2α-GnRH treatment which was evidenced by heat detection 3 to 4 days later. The strategy for presynchronization, involving the induction of ovulation 6–7 days before the start of the estrus synchronization protocol, results in more animals having ovulations after the first GnRH injection of the protocol [46]. If cows fail to ovulate after the first GnRH injection, the lifespan of the preovulatory follicle at the end of the synchronization protocol is prolonged, which is associated with the ovulation of aged oocytes, reduced embryo quality and low pregnancy rates [47,48].
Nevertheless, we considered the ovarian status and the concentration of steroid hormones on the day of TAI as determining factors in the successful ovulation and the achievement of an acceptable PR in the use of sexed semen. Most of the non-pregnant animals in group I (58.3%) had PF and CL on the day of TAI, while the majority of the animals that became pregnant (64.4%) bore PF without CL. This information and the significant (p < 0.05) difference in the ovarian status on the day of TAI between the different subgroups of cows in group II supported the aforementioned hypothesis. The absence of CL on the day of TAI in more than 70% of the pregnant animals after the OvSynch+PRID+eCG treatment was in agreement with other reports of the better synchronizing effect of progesterone-based protocols in comparison with conventional OvSynch.
The phenomenon behind the reduction in the efficiency of conventional OvSynch protocols may be incomplete luteolysis after the PGF2α injection, followed by inadequate levels of progesterone and the suppression of the second follicular wave, which makes the synchronization of ovulation and TAI impossible [23,49]. This is crucial for successful insemination with sexed semen because of the limited lifespan of the spermatozoa in the female genital organs, the reduced number of sperm per straw, and the potential pre-capacitation induced by the sorting procedure [14,50]. Different researchers stated that progesterone supplementation before timed AI imitates P4 concentration in the late luteal phase of a regular estrous cycle, leading to an increase an ovulation synchrony and P/AI [51,52,53]. This information is in agreement with the better pregnancy rate in group II observed in the current experiment.
Our hypothesis supposes that the diameters of the preovulatory follicles and steroid hormone concentrations can affect ovulation and, consequently, pregnancy after AI with sexed semen. The large size of PFs (in the range of 1.72 cm to 1.88 cm) was associated with a positive effect on the ovulation and PR in both groups. The determination of the highest mean diameter of the PFs in the pregnant animals from the second group and the relative enhancement of the sizes of the preovulatory follicles in the non-pregnant cows from the first group may be explained by the administration of eCG during the PGF2α injection. The influence of follicular size near the time of TAI on pregnancy success is still debatable. Bello et al. [54] determined the best conception rates after the ovulation of a 1.6 cm follicle, whereas conception rates decreased if the preovulatory follicle was either smaller or larger than 1.6 cm. According to Colazo et al. [55], after the second GnRH injection in synchronization programs with or without P4 supplementation, there was a variable range of ovulatory follicle sizes between lactating dairy and beef cows. They reported that follicles between 1.7 cm and 2.5 cm in diameter retain their capacity to ovulate, and cows with ovulatory follicles greater than 2.0 cm have an increased probability of pregnancy loss. Conversely, Berg et al. [56] found that follicles smaller than 1.5 cm ovulated significantly later, while cows with medium-sized and large follicles ovulated earlier than other animals. These controversial results presume that follicular size is not the only factor responsible for successful ovulation and conception.
In the current study, estrus synchronization treatments had a considerable effect on the functional status of the ovarian structures on the day of TAI. They were associated with the production of progesterone and estrogen from the CL and the preovulatory follicle, respectively. The significant (p < 0.05) difference in the mean P4 concentration between the non-pregnant and pregnant animals subjected to both treatments was probably due to the high percentage of animals bearing functional and active CL in the non-pregnant group at the time of TAI, caused by failed or incomplete luteal regression. The lower concentration of P4 determined in the pregnant animals from group II can be attributed to better luteolysis after the application of the Ovsynch+PRID+eCG protocol. In this regard, Garcia-Muñoz et al. [57] observed insignificant differences between treated and control groups after the administration of exogenous progesterone around the time of ovulation, and treatment with d-cloprostenol 120 h after ovulation. It is still not clear whether exogenous progesterone influences the sensitivity of the cow CL to PGF treatment. Although the same number of animals presented CL at the time of TAI, we observed a slight increase in P4 in non-pregnant subgroup II compared to pregnant subgroup I. One reason for this result could be the residual quantities or the delayed clearance of the supplemented progesterone. Cerri et al. [58] also reported augmented levels of P4 observed at the time of TAI after PRID removal and the first PGF2 alfa administration.
The significant difference (p < 0.05) in the mean E2 concentration between the pregnant and non-pregnant animals of the treated groups was an indicator of the increased steroid activity of the larger preovulatory follicles, which was confirmed by correlative analysis. This effect was clearly visible in group II, where the highest E2 concentration corresponded with the largest size of the preovulatory follicles. A similar increase in E2 in the larger PFs was observed in group I. On the other hand, the preovulatory follicles formed after Preselect-Ovsynch or Ovsynch+PRID+eCG treatment probably had different levels of estradiol production. Despite the insignificant difference between the mean diameters of the PFs in both subgroups subjected to Preselct-Ovsynch, a significantly (p < 0.05) higher mean concentration of estradiol-17β in the pregnant subgroup was observed. In this respect, Bridges and Fortune [59] emphasized that extended progesterone exposition after the incomplete regression of the CL had a negative indirect effect on estradiol-17β production. Herlihy et al. [26] also reported a positive correlation between increased preovulatory follicle size and circulating concentrations of E2 in progesterone-based synchronization protocols due to a longer period of preovulatory follicle growth. After P4 withdrawal, an increase in LH pulse frequency and mean LH concentrations promoted follicle growth and increased estrogen production. The second GnRH caused a rapid decrease in circulating estrogen concentrations, and OvSynch had less peak preovulatory E2 than the CIDR-TAI protocol. An additional factor in the increase in steroid activity in the preovulatory follicles of group II was probably the PMSG stimulation. According to Hirako et al. [60], the administration of 500 UI eCG in cattle lead to a significant increase in the release of estradiol-17β.
Despite the lack of significant differences in PR on day 30, the PR tended to increase after the Ovsynch+PRID+eCG treatment compared to the Preselect-Ovsynch treatment (38.6% vs. 57.5%; p = 0.09). The lower percentage of pregnant cows in group I, which was probably due to incomplete luteolysis, corresponded with the high P4 level on the day of TAI, which results in reduced pulsatile LH release and negatively affects final follicle maturation, oocyte maturity, and gamete transport [59,61]. Martins et al. [62] determined that complete functional luteolysis had a strong positive relationship with the time of ovulation. The lack of complete regression of the corpus luteum resulted in a low P/AI because of the increased progesterone concentration close to the time of AI in cows subjected to conventional Ovsynch treatment [63]. The higher pregnancy rate in group II can be explained by the inclusion of exogenous progesterone and eCG in the second protocol. In line with the current study, Colazo et al. [52] determined that the inclusion of PRID in the conventional Ovsynch protocol had a positive effect on P/AI. In fact, progesterone-releasing devices (CIDR or PRID) provide a slow release of progesterone, which regulates the number of estrogen receptors in the medial basal hypothalamus, increasing the responsiveness to estradiol, leading to a preovulatory LH surge. The withdrawal of the progesterone device leads to decreased progesterone and increased LH pulse frequency and mean concentrations of LH, which are associated with an increased number of LH receptors in the granulosa and theca cells, estradiol production by the follicle, and the stimulation of LH surges, thus resulting in ovulation [47,64,65]. Additional evidence for the positive influence of the Ovsynch+PRID+eCG treatment on pregnancy was the registration of a higher percentage of PR in the second group on day 60 (p < 0.05).
The pregnancy rate obtained with the Preselect-Ovsynch on day 30 after TAI (36.8%) was close to the 35.5% recorded by Karakaya-Bilen et al. [21], but lower than the 49.0% obtained by Drake et al. [22]. Lauber et al. [23] recorded 50% P/AI in presynchronized dairy cows on day 34 after double Ovsynch treatment and TAI with sexed semen. At the same time, the P/AI in Ovsynch+PRID+eCG (57.5%) was greater than the values observed in primiparous (49.5%) and multiparous (47.6%) lactating cows treated with a PRID-based protocol and inseminated with sexed semen [24]. In agreement with this study was Brozos et al. Ref. [60]’s finding of 54.3% P/AI after the use of PGF2α-GnRH pre-treatment and PRID-based protocols during the winter season. Furthermore, the sexed semen for the AI in our study originated from a bull selected for its high fertility. Drake et al. [22] investigated the interaction between treatment with sex-sorted semen and P/AI according to the bull fertility and detected deviations in the P/AI from 38.2% to 60.3%.
Similar to the findings of previous authors, we also observed decreasing PR between both consecutive ultrasound examinations for pregnancy, which was an indicator of late embryo loss. The embryo loss after the use of both synchronization protocols (28.5% and 13%) corresponded with the data obtained by Karakaya-Bilen et al. [21] and Guner et al. [24]. In disagreement with the obtained data was the embryo loss (5% and 6%) in the dairy cows on days 34 ± 3 and 80 ± 17 determined by Lauber et al. [23]; however, that study used a different estrus synchronization treatment. The higher percentage of embryo loss in group I can be attributed to the ovulation of smaller follicles at the time of TAI and the formation of CL, releasing less P4, which is critical for embryo development through the early gestation period [66,67]. In this respect, the diameter of the PFs on the day of TAI in the animals with pregnancy loss in subgroup I (≤1.7 mm) was below the calculated average size (1.8 ± 0.12 mm) of the PFs for all the pregnant animals.
The assertion of the effect of the ovarian status was supported by the significantly (p < 0.05) higher percentage of animals that became pregnant when PF without CL and diameters between 1.68 cm and 1.88 cm on the day of TAI were presented. It is known that the large luteal cells of the future CL, producing 80 to 90% of the progesterone, originate from granulosa cells [68]. Larger ovulatory follicles provided a greater number of granulosa cells, which resulted in a larger CL volume on day 7, producing enough progesterone for adequate pregnancy maintenance [66].
The difference (p < 0.05) between the mean values of the steroid hormones on the day of TAI between the non-pregnant and pregnant cows was an indicator of the significant effect of the E2 and P4 concentrations on the pregnancy results. A low P4 concentration at TAI in pregnant animals was also recorded by Souza et al. [69]. They observed that a blood progesterone level > 0.5 mg/mL at a time close to insemination decreases fertility by about 50%, while the P4 dropping to <0.5 ng/mL 2 days after the GnRH injection suggested a greater probability of pregnancy. Denicol et al. [70] underline the importance of the endocrine environment during follicular growth and the maturation of viable oocytes, and accept the size of the ovulatory follicle as a vital component in the probability of pregnancy. An inadequate endocrine profile at the time of TAI was shown to decrease oocyte quality, gamete transport, fertilization and the uterus’s ability to maintain pregnancy [71,72]. According to Brozos et al. [60], even after the second PGF2 treatment in the PRID-based protocol, a considerable number of cows had high progesterone (>1 ng/mL) at the time of AI; this occurred without a decrease in P4 concentration in the period between the first PGF2 injection and the AI.
All the aforementioned studies assumed that the ratio between estrogen and progesterone on the day of TAI is a very important factor in successful conception in synchronized dairy cows inseminated with sexed semen. Future detailed investigations with a large number of cyclic cows can clarify this matter.

5. Conclusions

The ovarian status and steroid hormone level on the day of TAI significantly affected the reproductive performance of dairy cows subjected to estrus synchronization and artificial insemination with sexed semen. The presence of a large PF, the production of more estrogen, a lack of CL, and low progesterone levels at the time of AI are factors that ensure acceptable pregnancy rates. The application of presynchronization treatment with the Ovsynch+PRID+eCG protocol can additionally improve pregnancy results after AI with sex-sorted semen. The confirmed strong correlation between the values of the PF and E2 concentrations allows ultrasound examination of the ovarian status of cows on the day of TAI to be recommended as a reliable tool for the selection of candidates for insemination with sexed semen. This will improve the utilization of sex-sorted semen from bulls with high genetic value, and accelerate genetic progress.

Supplementary Materials

The following are available online at https://www.mdpi.com/article/10.3390/ani13050896/s1, Table S1: Main factors influencing PF size and E2 concentration in dairy cows inseminated with sex-sorted semen (ANOVA main effects analysis). Figure S1: Ultrasound image of the ovarian status of dairy cows on day of TAI (A—preovulatory follicles in both ovaries without corpus luteum; B—corpus luteum located in the left ovary and preovulatory follicle in the right ovary); Figure S2: Ultrasound image of pregnancy in dairy cows on days 30 (A) and 60 (B) after TAI with sexed semen.

Author Contributions

Conceptualization and methodology, S.Y. and A.A.; investigation, S.Y., I.F., A.A., B.S. and B.I.; resources, D.Y. and B.S.; data curation, S.Y., E.K. and D.Z.; writing—original draft preparation, S.Y. and E.K.; writing—review and editing, S.Y. and E.K.; visualization, S.Y. and A.A.; supervision, S.Y.; project administration, D.Y. and D.Z.; funding acquisition, all contributors. All authors have read and agreed to the published version of the manuscript.

Funding

The research leading to these results received funding from the Ministry of Education and Science of the Republic of Bulgaria under the National Scientific Program INTELLIGENT ANIMAL HUSBANDRY, grant agreement no. Д01-62/18.03.2021.

Institutional Review Board Statement

The experimental work with animals was in accordance with Bulgarian Veterinary Law (25 January 2011) regarding the living conditions and welfare of livestock animals used for experimental purposes (farm license no. 3601/09.12.2020), which is adapted to European Union regulation 86/609. The use of farm animals was approved by the Ethics Committee at Trakia University (permission no. 233/11.04.2019) with the agreement of the Bulgarian National Animals Ethics Committee.

Informed Consent Statement

Informed consent was obtained from all subjects involved in the study.

Data Availability Statement

All data are included in the present article and its Supplementary Materials.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Holden, S.A.; Butler, S.T. Review: Applications and benefits of sexed semen in dairy and beef herds. Animal 2018, 12, s97–s103. [Google Scholar] [CrossRef] [PubMed]
  2. Probst, S.; Wasem, D.; Kobel, D.; Zehetmeier, M.; Flury, C. Greenhouse gas emissions from coupled dairy-beef production in Switzerland. Agrar. Schweiz 2019, 10, 440–445. [Google Scholar]
  3. Johnson, L.A. Sexing mammalian sperm for production of offspring: The state-of-the-art. Anim. Reprod. Sci. 2000, 60–61, 93–107. [Google Scholar] [CrossRef] [PubMed]
  4. Garner, D.L.; Evans, K.M.; Seidel, G.E. Sex-sorting sperm using flow cytometry/cell sorting. In Spermatogenesis: Methods in Molecular Biology; Carrell, D., Aston, K., Eds.; Humana Press: Totowa, NJ, USA, 2013; Volume 927, pp. 279–295. [Google Scholar] [CrossRef]
  5. Khalajzadeh, S.; Nejati-Javaremi, A.; Yeganeh, H.M. Effect of widespread and limited use of sexed semen on genetic progress and reproductive performance of dairy cows. Animal 2012, 6, 1398–1406. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  6. Butler, S.T.; Hutchinson, I.A.; Cromie, A.R.; Shalloo, L. Applications and cost benefits of sexed semen in pasture-based dairy production systems. Animal 2014, 8, 165–172. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  7. Ettema, J.F.; Thomasen, J.R.; Hjortø, L.; Kargo, M.; Ostergaard, S.; Sørensen, A.C. Economic opportunities for using sexed semen and semen of beef bulls in dairy herds. J. Dairy Sci. 2017, 100, 4161–4171. [Google Scholar] [CrossRef]
  8. Boneya, G. Sexed semen and major factors affecting its conception rate in dairy cattle. Int. J. Adv. Res. Biol. Sci. 2021, 8, 99–107. [Google Scholar] [CrossRef]
  9. Garner, D.L. Flow cytometric sexing of mammalian sperm. Theriogenology 2006, 65, 943–957. [Google Scholar] [CrossRef]
  10. Grant, V.J.; Chamley, L.W. Sex-Sorted Sperm and Fertility: An Alternative View. Biol. Reprod. 2007, 76, 184–188. [Google Scholar] [CrossRef] [Green Version]
  11. Rai, J. Sperm Sexing of Dairy Cattle: Economics, Animal Welfare and Technological Challenges. Curr. Sci. 2018, 114, 1438–1442. [Google Scholar] [CrossRef]
  12. Garner, D.L.; Seidel, G.E. History of commercializing sexed semen for cattle. Theriogenology 2008, 69, 886–895. [Google Scholar] [CrossRef] [PubMed]
  13. Healy, A.A.; House, J.K.; Thomson, P.C. Artificial insemination field data on the use of sexed and conventional semen in nulliparous Holstein heifers. J. Dairy Sci. 2013, 96, 1905–1914. [Google Scholar] [CrossRef] [PubMed]
  14. Nebel, R. Time of insemination relative to onset of activity threshold of Cow Manager® is associated with pregnancy risk when using Gender Selected™ semen for Jersey cattle. J. Dairy Vet. Sci. 2018, 5, 555653. [Google Scholar] [CrossRef]
  15. Seidel, G.E., Jr.; Schenk, J.L.; Herickhoff, L.A.; Doyle, S.P.; Brink, Z.; Green, R.D.; Cran, D.G. Insemination of heifers with sexed sperm. Theriogenology 1999, 52, 1407–1420. [Google Scholar] [CrossRef] [PubMed]
  16. DeJarnette, J.M.; Nebel, R.L.; Marshall, C.E.; Moreno, J.F.; McCleary, C.R.; Lenz, R.W. Effect of Sex-Sorted Sperm Dosage on Conception Rates in Holstein Heifers and Lactating Cows. J. Dairy Sci. 2008, 91, 1778–1785. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  17. Schenk, J.L.; Cran, D.G.; Everett, R.W.; Seidel, G.E., Jr. Pregnancy rates in heifers and cows with cryopreserved sexed sperm: Effects of sperm numbers per inseminate, sorting pressure and sperm storage before sorting. Theriogenology 2009, 71, 717–728. [Google Scholar] [CrossRef] [PubMed]
  18. Sales, J.N.S.; Crepaldi, G.A.; Girotto, R.W.; Souza, A.H.; Baruselli, P.S. Fixed-time AI protocols replacing eCG with a single dose of FSH were less effective in stimulating follicular growth, ovulation, and fertility in suckled-anestrus Nelore beef cows. Anim. Reprod. Sci. 2011, 124, 12–18. [Google Scholar] [CrossRef]
  19. Maicas, C.; Hutchinson, I.A.; Kenneally, J.; Grant, J.; Cromie, A.R.; Lonergan, P.; Butler, S.T. Fertility of fresh and frozen sex-sorted semen in dairy cows and heifers in seasonal-calving pasture-based herds. J. Dairy Sci. 2019, 102, 10530–10542. [Google Scholar] [CrossRef]
  20. DeJarnette, J.M.; McCleary, C.R.; Leach, M.A.; Moreno, J.F.; Nebel, R.L.; Marshall, C.E. Effects of 2.1 and 3.5 × 106 sex-sorted sperm dosages on conception rates of Holstein cows and heifers. J. Dairy Sci. 2010, 93, 4079–4085. [Google Scholar] [CrossRef] [Green Version]
  21. Karakaya-Bilen, E.; Yilmazbas-Mecitoglu, G.; Keskin, A.; Guner, B.; Serim, E.; Santos, J.E.P.; Gümen, A. Fertility of lactating dairy cows inseminated with sex-sorted or conventional semen after Ovsynch, Presynch-Ovsynch and Double-Ovsynch protocols. Reprod. Domest. Anim. 2019, 54, 309–316. [Google Scholar] [CrossRef]
  22. Drake, E.; Holden, S.A.; Aublet, V.; Doyle, R.C.; Millar, C.; Moore, S.G.; Maicas, C.; Randi, F.; Cromie, A.R.; Lonergan, P.; et al. Evaluation of delayed timing of artificial insemination with sex-sorted sperm on pregnancy per artificial insemination in seasonal-calving, pasture-based lactating dairy cows. J. Dairy Sci. 2020, 103, 12059–12068. [Google Scholar] [CrossRef] [PubMed]
  23. Lauber, M.; McMullen, B.; Parrish, J.; Fricke, P. Short communication: Effect of timing of induction of ovulation relative to timed artificial insemination using sexed semen on pregnancy outcomes in primiparous Holstein cows. J. Dairy Sci. 2020, 103, 10856–10861. [Google Scholar] [CrossRef] [PubMed]
  24. Guner, B.; Erturk, M.; Dursun, M.; Ozturk, B.; Yilmazbas-Mecitoglu, G.; Keskin, A.; Dikmen, S.; Gumen, A. Effect of oestrous expression prior to timed artificial insemination with sexed semen on pregnancy rate in dairy cows. Reprod. Domest. Anim. 2022, 58, 342–348. [Google Scholar] [CrossRef] [PubMed]
  25. Cerri, R.L.A.; Chebel, R.C.; Rivera, F.; Narciso, C.D.; Oliveira, R.A.; Amstalden, M.; Baez-Sandoval, G.M.; Oliveira, L.J.; Thatcher, W.W.; Santos, J.E.P. Concentration of progesterone during the development of the ovulatory follicle: II. Ovarian and uterine responses. J. Dairy Sci. 2011, 94, 3352–3365. [Google Scholar] [CrossRef]
  26. Herlihy, M.M.; Crowe, M.A.; Diskin, M.G.; Butler, S.T. Effects of synchronization treatments on ovarian follicular dynamics, corpus luteum growth, and circulating steroid hormone concentrations in lactating dairy cows. J. Dairy Sci. 2012, 95, 743–754. [Google Scholar] [CrossRef] [Green Version]
  27. Perry, G.A.; Cushman, R.A.; Perry, B.L.; Schiefelbein, A.K.; Northrop, E.J.; Rich, J.J.J.; Perkins, S.D. Role of preovulatory concentrations of estradiol on timing of conception and regulation of the uterine environment in beef cattle. Syst. Biol. Reprod. Med. 2020, 66, 12–25. [Google Scholar] [CrossRef]
  28. Perry, G.A.; Perry, B.L. Effect of preovulatory concentrations of estradiol and initiation of standing estrus on uterine pH in beef cows. Domest. Anim. Endocrinol. 2008, 34, 333–338. [Google Scholar] [CrossRef]
  29. Brozos, C.; Kiossis, E.; Hatzieffraimidis, S.; Praxitelous, A.; Gouvias, I.; Kanoulas, V.; Tsousis, G. Comparison of 5 Versus 7-Day Ovsynch + Progesterone Releasing Intravaginal Device Protocols (PRID) and a Modified G7G with an Option of Heat Detection Protocol for 1st Service in Lactating Dairy Cows. Animals 2021, 11, 2955. [Google Scholar] [CrossRef]
  30. Spencer, T.E.; Bazer, F.W. Conceptus signals for establishment and maintenance of pregnancy. Reprod. Biol. Endocrinol. 2004, 2, 49. [Google Scholar] [CrossRef] [Green Version]
  31. Baruselli, P.S.; Filho, M.S.; Ferreira, R.M.; Sales, J.N.; Gimenes, L.; Vieira, L.M.; Mendanha, M.F.; Bo, G.A. Manipulation of Follicle Development to Ensure Optimal Oocyte Quality and Conception Rates in Cattle. Reprod. Domest. Anim. 2012, 47, 134–141. [Google Scholar] [CrossRef] [Green Version]
  32. Seidel, G.E., Jr.; Schenk, J.L. Pregnancy rates in cattle with cryopreserved sexed sperm: Effects of sperm numbers per inseminate and site of sperm deposition. Anim. Reprod. Sci. 2008, 105, 129–138. [Google Scholar] [CrossRef] [PubMed]
  33. Norman, H.D.; Hutchison, J.L.; Miller, R.H. Use of sexed semen and its effect on conception rate, calf sex, dystocia, and stillbirth of Holsteins in the United States. J. Dairy Sci. 2010, 93, 3880–3890. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  34. Maicas, C.; Holden, S.A.; Drake, E.; Cromie, A.R.; Lonergan, P.; Butler, S.T. Fertility of frozen sex-sorted sperm at 4 × 106 sperm per dose in lactating dairy cows in seasonal-calving pasture-based herds. J. Dairy Sci. 2020, 103, 929–939. [Google Scholar] [CrossRef] [PubMed]
  35. Vazquez, J.M.; Martinez, E.A.; Parrilla, I.; Roca, J.; Gil, M.A.; Vazquez, J.L. Birth of piglets after deep intrauterine insemination with flow cytometrically sorted boar spermatozoa. Theriogenology 2003, 59, 1605–1614. [Google Scholar] [CrossRef] [PubMed]
  36. Mocé, E.; Graham, J.K.; Schenk, J.L. Effect of sex-sorting on the ability of fresh and cryopreserved bull sperm to undergo an acrosome reaction. Theriogenology 2006, 66, 929–936. [Google Scholar] [CrossRef] [PubMed]
  37. Carvalho, J.O.; Sartori, R.; Machado, G.M.; Mourão, G.B.; Dode, M.A.N. Quality assessment of bovine cryopreserved sperm after sexing by flow cytometry and their use in in vitro embryo production. Theriogenology 2010, 74, 1521–1530. [Google Scholar] [CrossRef]
  38. Bombardelli, G.D.; Soares, H.F.; Chebel, R.C. Time of insemination relative to reaching activity threshold is associated with pregnancy risk when using sex-sorted semen for lactating Jersey cows. Theriogenology 2016, 85, 533–539. [Google Scholar] [CrossRef]
  39. Caraviello, D.Z.; Weigel, K.A.; Fricke, P.M.; Wiltbank, M.C.; Florent, M.J.; Cook, N.B.; Nordlund, K.V.; Zwald, N.R.; Rawson, C.L. Survey of Management Practices on Reproductive Performance of Dairy Cattle on Large US Commercial Farms. J. Dairy Sci. 2006, 89, 4723–4735. [Google Scholar] [CrossRef] [Green Version]
  40. De Oliveira Marques, M.; Morotti, F.; Lorenzetti, E.; Bizarro-Silva, C.; Seneda, M.M. Intensified use of TAI and sexed semen on commercial farms. Anim. Reprod. 2018, 15, 197–203. [Google Scholar] [CrossRef]
  41. Walsh, D.P.; Fahey, A.G.; Lonergan, P.; Wallace, M. Economics of timed artificial insemination with unsorted or sexed semen in a high-producing, pasture-based dairy production system. J. Dairy Sci. 2022, 105, 3192–3208. [Google Scholar] [CrossRef] [PubMed]
  42. Nowicki, A.; Barański, W.; Baryczka, A.; Janowski, T. OvSynch protocol and its modifications in the reproduction management of dairy cattle herds—An update. J. Vet. Res. 2017, 61, 329–336. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  43. Bartolome, J.A.; Melendez, P.; Kelbert, D.; Swift, K.; McHale, J.; Hernandez, J.; Silvestre, F.; Risco, C.A.; Arteche, A.C.M.; Thatcher, W.W.; et al. Strategic use of gonadotrophin-releasing hormone (GnRH) to increase pregnancy rate and reduce pregnancy loss in lactating dairy cows subjected to synchronization of ovulation and timed insemination. Theriogenology 2005, 63, 1026–1037. [Google Scholar] [CrossRef] [PubMed]
  44. Dirandeh, E. Starting Ovsynch protocol on day 6 of first postpartum estrous cycle increased fertility in dairy cows by affecting ovarian response during heat stress. Anim. Reprod. Sci. 2014, 149, 135–140. [Google Scholar] [CrossRef] [PubMed]
  45. Bisinotto, R.S.; Ribeiro, E.S.; Martins, L.T.; Marsola, R.S.; Greco, L.F.; Favoreto, M.G.; Risco, C.A.; Thatcher, W.W.; Santos, J.E.P. Effect of interval between induction of ovulation and artificial insemination (AI) and supplemental progesterone for resynchronization on fertility of dairy cows subjected to a 5-d timed AI program. J. Dairy Sci. 2010, 93, 5798–5808. [Google Scholar] [CrossRef]
  46. Stevenson, J.L.; Dalton, J.C.; Santos, J.E.P.; Sartori, R.; Ahmadzadeh, A.; Chebel, R.C. Effect of Synchronization Protocols on Follicular Development and Estradiol and Progesterone Concentrations of Dairy Heifers. J. Dairy Sci. 2008, 91, 3045–3056. [Google Scholar] [CrossRef]
  47. Chebel, R.C.; Santos, J.E.P.; Cerri, R.L.A.; Rutigliano, H.M.; Bruno, R.G.S. Reproduction in Dairy Cows Following Progesterone Insert Presynchronization and Resynchronization Protocols. J. Dairy Sci. 2006, 89, 4205–4219. [Google Scholar] [CrossRef] [Green Version]
  48. Bruno, R.G.S.; Moraes, J.G.N.; Hernández-Rivera, J.A.H.; Lager, K.J.; Silva, P.R.B.; Scanavez, A.L.A.; Mendonça, L.G.D.; Chebel, R.C.; Bilby, T.R. Effect of an Ovsynch56 protocol initiated at different intervals after insemination with or without a presynchronizing injection of gonadotropin-releasing hormone on fertility in lactating dairy cows. J. Dairy Sci. 2014, 97, 185–194. [Google Scholar] [CrossRef] [Green Version]
  49. Pursley, J.R.; Mee, M.O.; Wiltbank, M.C. Synchronization of ovulation in dairy cows using PGF2α and GnRH. Theriogenology 1995, 44, 915–923. [Google Scholar] [CrossRef]
  50. Lu, K.H.; Seidel, G.E., Jr. Effects of heparin and sperm concentration on cleavage and blastocyst development rates of bovine oocytes inseminated with flow cytometrically-sorted sperm. Theriogenology 2004, 62, 819–830. [Google Scholar] [CrossRef]
  51. Alnimer, M.; Lubbadeh, W. Effect of Using Progesterone Releasing Intravaginal Device with Ovsynch Program on Reproduction in Dairy Cattle during Summer Season. Asian-Australas. J. Anim. Sci. 2003, 16, 1268–1273. [Google Scholar] [CrossRef]
  52. Colazo, M.G.; Dourey, A.; Rajamahendran, R.; Ambrose, D.J. Progesterone supplementation before timed AI increased ovulation synchrony and pregnancy per AI, and supplementation after timed AI reduced pregnancy losses in lactating dairy cows. Theriogenology 2013, 79, 833–841. [Google Scholar] [CrossRef] [PubMed]
  53. Dominguez, J.H.E.; Costa, D.S.; Centurion, V.J.; Faria, F.J.C. Pregnancy rate of Nelore females inseminated with male-sexed semen. Anim. Reprod. Sci. 2011, 129, 127–131. [Google Scholar] [CrossRef] [PubMed]
  54. Bello, N.M.; Steibel, J.P.; Pursley, J.R. Optimizing Ovulation to First GnRH Improved Outcomes to Each Hormonal Injection of Ovsynch in Lactating Dairy Cows. J. Dairy Sci. 2006, 89, 3413–3424. [Google Scholar] [CrossRef] [Green Version]
  55. Colazo, M.G.; Behrouzi, A.; Ambrose, D.J.; Mapletoft, R.J. Diameter of the ovulatory follicle at timed artificial insemination as a predictor of pregnancy status in lactating dairy cows subjected to GnRH-based protocols. Theriogenology 2015, 84, 377–383. [Google Scholar] [CrossRef]
  56. Berg, H.F.; Heringstad, B.; Alm-Kristiansen, A.H.; Kvale, V.G.; Dragset, K.I.; Waldmann, A.; Ropstad, E.; Kommisrud, E. Ovarian follicular response to oestrous synchronisation and induction of ovulation in Norwegian Red cattle. Acta Vet. Scand. 2020, 62, 1–8. [Google Scholar] [CrossRef]
  57. Garcia-Muñoz, A.; Valldecabres-Torres, X.; Newcombe, J.R.; Cuervo-Arango, J.; Garcia-Rosello, E. Effect of exogenous progesterone administration on luteal sensitivity to PGF during the early development of the corpus luteum in mares and cows. Reprod. Domest. Anim. 2017, 52, 1074–1080. [Google Scholar] [CrossRef]
  58. Cerri, R.L.; Rutigliano, H.M.; Bruno, R.G.S.; Santos, J.E. Progesterone concentration, follicular development and induction of cyclicity in dairy cows receiving intravaginal progesterone inserts. Anim. Reprod. Sci. 2009, 110, 56–70. [Google Scholar] [CrossRef]
  59. Bridges, P.J.; Fortune, J.E. Characteristics of developing prolonged dominant follicles in cattle. Domest. Anim. Endocrinol. 2003, 25, 199–214. [Google Scholar] [CrossRef] [PubMed]
  60. Hirako, M.; Kamomae, H.; Domeki, I. Luteotropic Effect of Pregnant Mare Serum Gonadotropin in Cattle. J. Vet. Med. Sci. 1995, 57, 317–321. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  61. Barletta, R.V.; Carvalho, P.D.; Santos, V.G.; Melo, L.F.; Consentini, C.E.; Netto, A.S.; Fricke, P.M. Effect of dose and timing of prostaglandin F2α treatments during a Resynch protocol on luteal regression and fertility to timed artificial insemination in lactating Holstein cows. J. Dairy Sci. 2018, 101, 1730–1736. [Google Scholar] [CrossRef]
  62. Martins, J.P.N.; Policelli, R.K.; Neuder, L.M.; Raphael, W.; Pursley, J.R. Effects of cloprostenol sodium at final prostaglandin F2α of Ovsynch on complete luteolysis and pregnancy per artificial insemination in lactating dairy cows. J. Dairy Sci. 2011, 94, 2815–2824. [Google Scholar] [CrossRef]
  63. Wiltbank, M.C.; Baez, G.M.; Cochrane, F.; Barletta, R.V.; Trayford, C.R.; Joseph, R.T. Effect of a second treatment with prostaglandin F2α during the Ovsynch protocol on luteolysis and pregnancy in dairy cows. J. Dairy Sci. 2015, 98, 8644–8654. [Google Scholar] [CrossRef] [Green Version]
  64. Rhodes, F.M.; McDougall, S.; Burke, C.R.; Verkerk, G.A.; Macmillan, K.L. Invited Review: Treatment of Cows with an Extended Postpartum Anestrous Interval. J. Dairy Sci. 2003, 86, 1876–1894. [Google Scholar] [CrossRef]
  65. Gümen, A.; Wiltbank, M.C. Length of progesterone exposure needed to resolve large follicle anovular condition in dairy cows. Theriogenology 2005, 63, 202–218. [Google Scholar] [CrossRef]
  66. Vasconcelos, J.L.; Sartori, R.; Oliveira, H.N.; Guenther, J.G.; Wiltbank, M.C. Reduction in size of the ovulatory follicle reduces subsequent luteal size and pregnancy rate. Theriogenology 2001, 56, 307–314. [Google Scholar] [CrossRef]
  67. Perry, G.A. Effect of Ovulatory Follicle Size and Standing Estrus on Circulating Hormone Concentrations and Interval to Ovulation; South Dakota Beef Report; South Dakota State University: Brookings, SD, USA, 2005; Volume 24, pp. 131–140. Available online: https://openprairie.sdstate.edu/sd_beefreport_2005/27 (accessed on 10 December 2022).
  68. Farin, C.E.; Moeller, C.L.; Sawyer, H.R.; Gamboni, F.; Niswender, G.D. Morphometric Analysis of Cell Types in the Ovine Corpus Luteum throughout the Estrous Cycle. Biol. Reprod. 1986, 35, 1299–1308. [Google Scholar] [CrossRef] [Green Version]
  69. Souza, A.H.; Gümen, A.; Silva, E.P.B.; Cunha, A.P.; Guenther, J.N.; Peto, C.M.; Caraviello, D.Z.; Wiltbank, M.C. Supplementation with Estradiol-17β before the Last Gonadotropin-Releasing Hormone Injection of the Ovsynch Protocol in Lactating Dairy Cows. J. Dairy Sci. 2007, 90, 4623–4634. [Google Scholar] [CrossRef] [Green Version]
  70. Denicol, A.C.; Lopes, G., Jr.; Mendonça, L.G.D.; Rivera, F.A.; Guagnini, F.; Perez, R.V.; Lima, J.R.; Bruno, R.G.S.; Santos, J.E.P.; Chebel, R.C. Low progesterone concentration during the development of the first follicular wave reduces pregnancy per insemination of lactating dairy cows. J. Dairy Sci. 2012, 95, 1794–1806. [Google Scholar] [CrossRef] [Green Version]
  71. Atkins, J.A.; Smith, M.F.; Wells, K.J.; Geary, T.W. Factors affecting preovulatory follicle diameter and ovulation rate after gonadotropin-releasing hormone in postpartum beef cows. Part I: Cycling cows. J. Anim. Sci. 2010, 88, 2300–2310. [Google Scholar] [CrossRef] [Green Version]
  72. Souza, A.H.; Narciso, C.D.; Batista, E.O.S.; Carvalho, P.D.; Wiltbank, M.C. Effect of uterine environment on embryo production and fertility in cows. Anim. Reprod. 2014, 11, 159–167. [Google Scholar]
Animals 13 00896 g001 550
Figure 1. Preselect-OvSynch (A) and OvSynch+PRID+eCG (B) estrus synchronization protocols in dairy cows (US—ultrasound examination; PGF2α—prostaglandin F2 alfa; GnRH—gonadotropin-releasing hormone; PRID—progesterone-releasing intravaginal device; TAI—timed artificial insemination).
Figure 1. Preselect-OvSynch (A) and OvSynch+PRID+eCG (B) estrus synchronization protocols in dairy cows (US—ultrasound examination; PGF2α—prostaglandin F2 alfa; GnRH—gonadotropin-releasing hormone; PRID—progesterone-releasing intravaginal device; TAI—timed artificial insemination).
Animals 13 00896 g001
Table
Table 1. Ovarian status and steroid hormone concentration on day of TAI, pregnancy rate (PR) and embryo loss according to different estrus synchronization treatments.
Table 1. Ovarian status and steroid hormone concentration on day of TAI, pregnancy rate (PR) and embryo loss according to different estrus synchronization treatments.
ParametersGroup I *
(n = 38)		Group II **
(n = 40)
Non-Pregnant Subgroup
(n = 24)		Pregnant Subgroup
(n = 14)		Non-Pregnant Subgroup
(n = 17)		Pregnant Subgroup
(n = 23)
Ovarian status
Preovulatory follicle with corpus luteum %, (n/n)58.3 (14/24)35.7 (5/14)29.4 (5/17) 113 (3/23) 1
Preovulatory follicle without corpus luteum %, (n/n)41.7 (10/24)64.3 (9/14)70.6 (12/17) 287 (20/23) 2
Diameter of preovulatory follicle (mean ± SD, cm) 1.60 ± 0.24 a1.72 ± 0.20 a1.68 ± 0.19 a1.88 ± 0.10 b
Steroid hormone concentrations
Progesterone (mean ± SD, ng/mL)2.35 ± 3.07 a0.68 ± 0.26 b0.82 ± 0.24 b0.52 ± 0.12 c
Estradiol-17β (mean ± SD, pg/mL)7.32 ± 0.80 a10.24 ± 0.36 b10.04 ± 2.12 b12.86 ± 2.26 c
PR on day 30 %, (n/n)36.8 (14/38)57.5 (23/40)
PR on day 60 %, (n/n)26.3 (10/38) a50 (20/40) b
Pregnancy loss %28.5 (4/14)13 (3/23)
* Preselect-OvSynch protocol, ** OvSynch+PRID-7-day+eCG protocol. Values with different superscript letters within a row are different at p < 0.05. Values with different superscript numbers within a column are different at p < 0.05.
Table
Table 2. Ovarian status and steroid hormone concentration on day of TAI according to pregnancy status of the cows.
Table 2. Ovarian status and steroid hormone concentration on day of TAI according to pregnancy status of the cows.
GroupsNon-Pregnant
(n = 41)		Pregnant
(n = 37)
Ovarian status on day of TAI
Preovulatory follicle with corpus luteum %, (n/n)46.3 (19/41) a21.6 (8/37) b,1
Preovulatory follicle without corpus luteum %, (n/n)53.7 (22/41) a78.4 (29/37) b,2
Diameter of preovulatory follicle (mean ± SD, cm) 1.64 ± 0.26 a1.80 ± 0.12 b
Steroid hormone concentrations
Progesterone (mean ± SD, ng/mL)1.58 ± 1.06 a0.59 ± 0.28 b
Estradiol-17β (mean ± SD, pg/mL)8.68 ± 1.82 a12.35 ± 2.62 b
Values with different superscript letters within a row are different at p < 0.05. Values with different superscript numbers within a column are different at p < 0.05.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Yotov, S.; Fasulkov, I.; Atanasov, A.; Kistanova, E.; Sinapov, B.; Ivanova, B.; Yarkov, D.; Zaimova, D. Influence of Ovarian Status and Steroid Hormone Concentration on Day of Timed Artificial Insemination (TAI) on the Reproductive Performance of Dairy Cows Inseminated with Sexed Semen. Animals 2023, 13, 896. https://doi.org/10.3390/ani13050896

AMA Style

Yotov S, Fasulkov I, Atanasov A, Kistanova E, Sinapov B, Ivanova B, Yarkov D, Zaimova D. Influence of Ovarian Status and Steroid Hormone Concentration on Day of Timed Artificial Insemination (TAI) on the Reproductive Performance of Dairy Cows Inseminated with Sexed Semen. Animals. 2023; 13(5):896. https://doi.org/10.3390/ani13050896

Chicago/Turabian Style

Yotov, Stanimir, Ivan Fasulkov, Anatoli Atanasov, Elena Kistanova, Branimir Sinapov, Boyana Ivanova, Dobri Yarkov, and Darina Zaimova. 2023. "Influence of Ovarian Status and Steroid Hormone Concentration on Day of Timed Artificial Insemination (TAI) on the Reproductive Performance of Dairy Cows Inseminated with Sexed Semen" Animals 13, no. 5: 896. https://doi.org/10.3390/ani13050896

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop