Oocyte competence and gene expression in parthenogenetic produced embryos from repeat breeder and normally fertile buffaloes (Bubalus bubalis) raised in sub-humid tropical climate.

The reproductive management of the buffalo species still faces several unresolved problems, which directly affect the productivity of the herd, one of them being the presence of repeat breeder females. Given this scenario, this study aimed to verify the developmental competence of oocytes obtained from repeat breeder females and submitted to parthenogenetic activation. In addition, embryo gene expression was compared to normally fertile females. Murrah buffaloes were divided into two groups: repeat breeder (RB, n = 8) and normally fertile or control (CR, n = 7). Cumulus-oocyte complexes (COCs) were aspirated by transvaginal ovum pick-up from estrus synchronized females. The COCs were submitted to IVM for 24 h, and subsequently, the oocytes were activated using ionomycin, followed by 6-DMAP. Afterwards, the presumptive parthenotes were cultured for six or seven days in a microenvironment of 5 % CO2, 5 % O2, and 90 % N2 at 38.5 °C. The expression of OCT4, GLUT1, BCL2 and TFAM genes from blastocysts was evaluated. The overall COCs recovery rate was 70.9 % (190/268). The maturation (57.8 vs 71.1), cleavage (45.2 vs 62.2) and blastocyst (30.1 vs 45.9) rates did not differ (P > 0.05) between RB and CR females, respectively. Similarly, no significant difference (P > 0.05) was observed for the expression of studied genes in both RB and CR females. In conclusion, oocytes obtained from RB were as developmentally competent as those collected from CR females, with similar energy metabolism and in vitro development capacity. Thus, the low fertility rate of repeat breeder buffaloes, when compared to normal cyclic females, must be due to subsequent events to the blastocyst stage.

Current Insights in the Repeat Breeder Cow Syndrome.

Cows can have difficulties becoming pregnant, and in certain cases, these reproductive failures do not have an evident cause. Furthermore, when these failures are repeated three or more times with estrous cycles of normal duration and in the absence of evident clinical signs, it is considered repeat breeder cow (RBC) syndrome. A substantive incidence of RBC syndrome has been reported all over the world, which severely affects the farm economy. This paper reviews those studies particularly focused on RBC syndrome from 2000 to 2023 but also includes consolidated information until this date. Hormonal imbalances, undetectable oviductal or uterine defects, or poor oocyte or embryo quality have been reported as causes of RBC syndrome, while subclinical endometritis has been considered a relevant causal agent. However, it is unresolved why this condition is recurrent in certain animals, despite the implementation of corrective management actions or treatments. Recent studies evaluate the putative role of certain genes, factors, hormones, or proteins in the pathogenesis of RBC syndrome. Numerous risk factors contribute to the appearance of this syndrome, and some of them could be mitigated to partially prevent this infertility, while others cannot be changed. Due to the complexity of this syndrome, it is important to increase knowledge about the mechanisms involved, develop new diagnostic tools to differentiate causal agents, and implement new treatments to restore fertility. There is consensus about the huge repercussions of this syndrome on farm profitability, but further studies are now needed to describe its economic impact.

Repeat breeding: prevalence and potential causes in dairy cows at different milk pocket areas of Bangladesh.

The objective of this study was to figure out the prevalence and probable causes of repeat breeding (RB) in dairy cows. Hence, a cross-sectional study was conducted on randomly selected 265 dairy farms in Sirajganj, Bogura, Rangpur, Satkhira, and Munshiganj districts of Bangladesh from December 2018 to February 2019. Data were collected through a direct interview method using a survey questionnaire. The reproductive organs of repeat breeder cows were examined for pathological, infectious, and functional reasons, and genital tract abnormalities. Additionally, the influence of nutrition, season, and age on the frequency of RB was recorded. The prevalence of RB was 28% among the 3824 cows investigated. Among the total repeat breeder cases, 72.54% of RB cases were found in Holstein-Friesian crossbred, 23.90% in Jersey crossbred, 1.50% in Sahiwal crossbred, and 2.06% in indigenous cows. The prevalence of RB was significantly highest (P < 0.01) in Satkhira (44.35%) and lowest in the Munshiganj district (15.87%). Data indicated that a major proportion of cows significantly (P < 0.05) faced RB problems due to functional causes (34.18%), followed by pathological causes (28.01%), genital tract abnormalities (21.32%), and infectious causes (16.49%). Furthermore, the cows were remarkably (P < 0.001) affected in RB during the summer season and nutritional deficient diseases like milk fever (70%). Age (3-7 years) had a significant (P < 0.001) effect on the RB occurrence (90%) in crossbred cows. However, particular focus should be given to systematic breeding, balanced nutrition, artificial inseminator efficiency, and hygienic inseminating tools to reduce RB incidence in high-yielding crossbred cows.

Direct transfer of a single frozen-thawed in vitro-produced embryo to avoid twin pregnancy in dairy cows.

Fertility of cow receiving fixed-time artificial insemination (FTAI) was compared with cow in which a single frozen-thawed in vitro-produced (IVP) embryo was fixed-time transferred (FTET) to avoid twin pregnancy. The study population was comprised of 596 lactating dairy cows synchronized for oestrus: 440 were fixed-time inseminated (AI cows), and 156 were given GnRH treatment at the time of embryo transfer (ET cows) 8 days post-oestrus. Of the 596 cows, 235 (39.4%) became pregnant: 175 (39.8%) AI cows and 60 (39.8%) ET cows. Twin pregnancy was recorded in 16% of the AI pregnant cows (28/175), whereas no ET cows had twins (0/60). Significant interaction (p < .01) was observed between breeding technique (FTAI vs FTET) and repeat (RB) or not repeat breeding (NRB) for the likelihood of pregnancy. This meant that using RB AI cows as reference, the odds ratio for pregnancy in RB ET cows was 2.2 (p = .04). In conclusion, transfer of a frozen IVP embryo proved useful to prevent the risk of twin pregnancy without affecting fertility.

Clinical Overview of Luteal Deficiency in Dairy Cattle.

Luteal deficiency is defined as reduced progesterone (P4) steroidogenesis by the corpus luteum (CL), either in the amount or duration, or both. This work provides a clinical overview of the current understanding of luteal deficiency and its association with low fertility in dairy cows. Low plasma P4 concentrations during the luteal phase post-artificial insemination (AI) are associated with lower conception rates. Treatments post-AI with P4, gonadotropin-releasing hormone (GnRH) or human chorionic gonadotropin (hCG) improve fertility in some conditions. Sub-luteal function during the late embryonic period (at pregnancy diagnosis, i.e., 28-34 days post-AI), is just one factor among other factors associated with pregnancy loss. Treatment with P4 in cows with one CL favors pregnancy maintenance, while GnRH treatment does the same in cows carrying twins. The diagnosis of sub-luteal function can be made clinically on the basis of plasma or milk P4 concentrations. Automated in-line milk P4 analysis systems to diagnose luteal activity emerge as a very interesting tool in dairy herds. Monitoring plasma or milk P4 concentrations with the help of Doppler ultrasonography to assess the CL function would allow individualizing the luteal phase support.

Genetic structure of some candidate genes of repeat breeder syndrome in Egyptian buffaloes.

BACKGROUND: This study aimed to explore the association between polymorphisms in three genes: leptin (LEP), leptin receptor (LEPR), and BMP4, and incidence of repeat breeding in Egyptian buffaloes. METHODS: DNA was extracted from 160 female buffaloes, involving 108 fertile and 52 repeat breeders. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Sequence analysis and alignment were performed by employing NCBI/BLAST/blastn suite, to identify SNPs among different patterns and alleles. We utilized PredictSNP software to predict the non-synonymous SNPs influences on protein function. Moreover, the conservation score of the amino acids within the target proteins was computed by ConSurf server. RESULTS: The genotyping results showed that LEP and BMP4 genes were monomorphic (CC, GG) in all tested fertile and repeat breeder buffaloes. Leptin gene sequencing showed a non-synonymous C73T SNP, replacing R to C at position 25 within the leptin polypeptide (position 4 in the mature form; R4C) which is a neutral mutation, not affecting function or structure of LEP protein. For LEPR, one synonymous SNP (T102C) and two non-synonymous SNPs (A106G and C146A), triggering V967A and G954C replacements, respectively in LEPR protein. Moreover, they are neutral mutations. Sequencing results of BMP4 showed HinfI restriction site indicate fixed GG genotype (CC genotype in the anti-sense strand) in all sequenced samples. No SNPs were observed within the amplified region. CONCLUSION: Genotyping and sequencing results of the surveyed three genes revealed that there is no association between these genes mutations and the incidence of repeat breeding in Egyptian buffaloes.

Reproductive performance of beef cattle with ovarian hypofunction and repeat breeding in Jepara Regency, Central Java, Indonesia.

BACKGROUND AND AIM: Reproductive disorders keep the beef cattle population in Jepara Regency, Central Java, Indonesia, from increasing. Ovarian hypofunction and repeat breeding are the most common reproductive disorders, leading to large economic losses for traditional breeders. However, the impact of poor reproductive performance among traditional breeders is not well-known. This study aimed to investigate the reproductive performance of beef cattle with ovarian hypofunction and repeat breeding in Jepara Regency. MATERIALS AND METHODS: We determined cattle's reproductive status by rectal examination and anamnesis, assessing reproductive performance in 28 cows with repeat breeding and 27 cows with ovarian hypofunction. The following parameters were measured: Postpartum estrous (PPE), days open (DO), service per conception (S/C), and calving interval (CI). The data came from livestock records from animal recording cards, iSIKHNAS, and estimated births from the insemination date that produced a pregnancy. RESULTS: In beef cattle diagnosed with ovarian hypofunction, S/C, PPE, DO, and CI were 1.28, 257 days, 265 days, and 18 months, respectively. The length of CI caused by long PPE may be due to improper nutrition and calf weaning delays. In beef cattle with repeat breeding, S/C, PPE, DO, and CI were 4.15, 106 days, 210 days, and 16 months, respectively. The length of CI was caused by long DO due to pregnancy failure at the first estrus. CONCLUSION: Hypofunction and repeat breeding reduce the reproductive performance of beef cattle in the Jepara Regency. The cows' health conditions pre- and postpartum can be optimized by providing high-quality feed to enhance reproductive performance.

Profiles of progesterone and bovine interferon-τ in repeat breeding and non-repeat breeding Aceh cows.

AIM: This study aimed at determining the profiles of progesterone and bovine interferon-τ (bIFN-τ) and the correlation between the two in repeat breeding (RB) Aceh cattle and non-RB Aceh cattle. MATERIALS AND METHODS: The study was performed on five RB and five non-RB Aceh cows. These cows were subjected to estrous synchronization using the prostaglandin F2 alpha hormone, which was followed by artificial insemination (AI). Serum samples were collected on days 5, 6, 7, 15, 16, and 17 after AI to measure the concentration of progesterone at the beginning and end of the luteal phase and from days 14 to 18 after AI to measure the concentration of bIFN-τ. The concentrations of progesterone and bIFN-τ were determined using enzyme-linked immunosorbent assay. Pregnancy examinations were performed by ultrasonography on days 25, 35, 45, and 55 after AI. Data for progesterone and bIFN-τ concentrations were analyzed using the Mann-Whitney and t-tests, and the correlation between progesterone and bIFN-τ was analyzed using the Spearman correlation test. RESULTS: The average concentration of progesterone in RB Aceh cows tended to be lower than non-RB Aceh cows, but it was not significantly different (p>0.05). Similar results also found in the concentration of bIFN-τ which RB Aceh cows tended to have lower bIFN-τ concentrations compared to non-RB Aceh cows, but it was also not significantly different (p>0.05). Moreover, the concentrations of progesterone and bIFN-τ in RB and non-RB Aceh cows did not show a significant correlation (p>0.05). These results of the ultrasonography showed that non-RB Aceh cows were pregnant from day 25 to day 55 after AI, whereas RB Aceh cows were not pregnant and had early embryonic death. CONCLUSION: The concentrations of progesterone and bIFN-τ in non-RB Aceh cows tended to be higher than those in RB Aceh cows, although, it was not significantly different. Non-RB Aceh cows were able to maintain pregnancy until day 55, whereas RB Aceh cows were diagnosed with early embryonic death before day 25 after AI.

Metabolomic profiles of plasma and uterine luminal fluids from healthy and repeat breeder Holstein cows.

BACKGROUND: Repeat breeding is a critical reproductive disorder in cattle. The problem of repeat breeder cattle remains largely unmanageable due to a lack of informative biomarkers. Here, we utilized metabolomic profiling in an attempt to identify metabolites in the blood plasma and uterine luminal fluids. We collected blood and uterine fluid from repeat breeder and healthy cows on day 7 of the estrous cycle. RESULTS: Metabolomic analysis identified 17 plasma metabolites detected at concentrations that distinguished between the two groups, including decreased various bile acids among the repeat breeders. However, no metabolites that varied significantly were detected in the uterine luminal fluids between two groups. Among the plasma samples, kynurenine was identified as undergoing the most significant variation. Kynurenine is a metabolite produced from tryptophan via the actions of indoleamine 2,3-dioxygenase (IDO). As IDO is key for maternal immune tolerance and induced in response to interferon tau (IFNT, ruminant maternal recognition of pregnancy factor), we examined the responsiveness to IFNT on peripheral blood mononuclear cells (PBMC) isolated from healthy and repeat breeder cows. The mRNA expression of IFNT-response makers (ISG15 and MX2) were significantly increased by IFNT treatment in a dose-dependent manner in both groups. Although treatment with IFNT promoted the expression of IDO in PBMCs from both groups, it did so at a substantially reduced rate among the repeat breeder cows, suggesting that decreased levels of kynurenine may relate to the reduced IDO expression in repeat breeder cows. CONCLUSIONS: These findings provide valuable information towards the identification of critical biomarkers for repeat breeding syndrome in cattle.

Effect of dietary n-3 polyunsaturated rich fish oil supplementation on ovarian function and interferon stimulated genes in the repeat breeding cow.

Dietary n-3 polyunsaturated fatty acids (n-3 PUFA) improve utero-ovarian functions and embryonic survival in postpartum dairy cows. Because early embryonic mortality is the major cause of repeat breeding (RB) in cows, there was investigation of the effect of dietary supplementation of n-3 PUFA [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] rich fish oil (FO) from -2 to +2 weeks of artificial insemination on the size of preovulatory follicle (POF), serum progesterone (P4) and relative abundance of the mRNA of interferon stimulated genes (ISG) that encode for these proteins in the peripheral blood leukocytes (PBL) in the RB cow (n = 12). The diet of control group was supplemented with palm oil (PO). The results indicated serum concentrations of EPA and DHA were greater by 4.6- and 3.5-fold, respectively at the end of feeding study in the RB cows of the FO group. The diameter of POF was larger by 2.2 mm in FO group; however, serum P4 did not vary from day 14-20 post-artificial insemination. Greater abundance of ISG mRNA transcripts such as ISG15, RTP4, Mx2 and OAS1 in the PBL of pregnant cows of FO group indicates day 20 conceptuses produced more IFN-τ. It is concluded that supplementation of FO during the breeding period increased the size of POF and enhanced the abundance of ISG mRNA transcripts in RB cows that became pregnant.

Serum glucose, urea nitrogen, cholesterol, and total proteins in crossbred repeat breeder and normally cyclic cows.

OBJECTIVE: This study was designed to determine and compare the serum glucose, urea nitrogen, cholesterol, and total protein (TP) level in crossbred repeat breeder (RB) and normally cyclic cows to find out the relationship of these metabolic factors with repeat breeding syndrome (RBS). MATERIALS AND METHODS: A total of 592 breedable cows from 34 farms were examined from Mymensingh and Chittagong districts. Seventy cows were identified as RB cows and another 10 cows were randomly selected as normally cyclic control cows for this study. Blood sample from each cow was collected and the serum was separated. The serum samples were analyzed by auto blood analyzer. RESULTS: Cows affected with RBS had significant variation in their glucose, urea, and cholesterol levels. Serum glucose (43.00 gm/dl) level was significantly lower than in normally cyclic cows. On the other hand, serum urea and cholesterol levels were significantly higher than in normally cyclic cows. However, the TP concentrations did not differ between RB and cyclic cows. RB cows had a lower trend (6.815 mg/dl) of serum TP than in normally cyclic cows. CONCLUSION: This research might help scientists and veterinarians to understand that the high serum urea and cholesterol level along with low glucose and TP level could have some effect in the development of RBS in crossbred cows. It will potentially help veterinary practitioners and farmers to take preventive measures against RBS of crossbred cows.

Cortisol and Blood Urea Nitrogen Profiles in Fertile and Repeat-breeder Holstein-friesian Crossbred Cows.

BACKGROUND AND OBJECTIVE: Repeat breeding, in which conception fails after repeated inseminations is a major problem in the dairy industry that leads to economic losses. To examine the role of stress under this condition, this study was conducted to evaluate cortisol and blood urea nitrogen (BUN) levels in fertile and repeat-breeder Holstein-friesian crossbred cows in smallholder farms. MATERIALS AND METHODS: Thirty cows were divided into two groups: Fertile and repeat-breeder cows, with 15 cows per group. Blood samples were collected from the caudal vein at night, 8 h after feeding, once in the oestrus phase during two oestrus cycles and cortisol levels were analyzed by using an enzyme-linked immunosorbent assay with a commercial kit. The BUN was analyzed by the urease and glutamate dehydrogenase method. RESULTS: Significant differences in cortisol and BUN levels were observed between fertile and repeat-breeder cows. Cortisol levels were higher in the repeat-breeder group (6.860±1.427 ng mL-1) compared to those in the fertile group (3.145±1.103 ng mL-1). Furthermore, BUN levels were also higher in repeat-breeder cows (31.45±4.70 mg dL-1) than in fertile cows (27.30±2.69 mg dL-1). CONCLUSION: Cortisol and BUN levels above the normal range may contribute to repeat breeding in Holstein-friesian crossbred cows.

Effect of synchronization protocols on reproductive indices, progesterone profile and fertility under subtropical environmental conditions in repeat breeder Holstein cows.

The objectives were to evaluate the reproductive indices and survival analysis of pregnancy outcomes in multiparous repeat breeder Holstein cows (n = 557). The cows were synchronized to ovulate by Ovsynch, new controlled internal drug release device (N-CIDRsynch), and once-used CIDR device (U-CIDRsynch). The pregnancy per AI at 28 days post-insemination (P/AI 28) in the N-CIDRsynch group (28.75%) was significantly (COR = 1.49; p = 0.011) greater than that reported in the Ovsynch (23.46%) and U-CIDRsynch (21.73%) groups. Furthermore, the pregnancy per AI at day 75 post-insemination (P/AI 75) in the N-CIDRsynch group was significantly greater than the Ovysync group (COR = 1.35; p = 0.050). The repeat breeder cows received a N-CIDR device had a significantly higher progesterone level on day 2 and day 4 of CIDR insertion (1.38 and 1.67 ng/ml, respectively) than those received a U-CIDR device or the control group (p = 0.012 and 0.001, respectively). The Cox regression model recorded significant associations for synchronization protocols, THI at the TAI and season of calving with the hazard of P/AI 28 and P/AI 75 (p = 0.044 and 0.046; 0.001 and 0.005; 0.003 and 0.001, respectively). Multiparous repeat breeder cows (>3) had a lower hazard ratio (HR) of P/AI 28 than that reported in the reference (2nd parity) group (HR = 0.74, p = 0.050). The repeat breeder cows inseminated at 76-80 and >80 temperature-humidity index (THI) had significantly lower HR of P/AI 28 than those inseminated at the baseline (<70) THI value (HR = 0.73 and 0.30, p = 0.036 and 0.001, respectively). The current results indicate that the use of N-CIDR synch protocol may achieve satisfactory pregnancy outcomes in repeat breeder cows.

Chronic inflammatory and degenerative endometrial lesions in subfertile Criollo Limonero cattle; a B. taurus Latin-American breed threatened with extinction; A case-control study.

Criollo Limonero is a tropical Bos taurus breed for sustainable dual purpose (milk and beef) production in the South-American tropics, which is currently threatened with extinction. The objective was to perform a clinical evaluation and histopathological assessment of uterine biopsy samples of repeat breeder (RB) Criollo Limonero cattle to determine the occurrence of pathological conditions as potential causes of subfertility. Twenty-four Criollo Limonero cattle [18 cows (5-13 years old) and 6 heifers (6-7.5 years old)] that had failed to conceive after four or more services were considered for this study. Additionally, five cows with history of adequate reproductive performance were used as a control group. Animals were submitted to physical exam, vaginoscopy, and ultrasonographical evaluation of the reproductive tract. Uterine biopsy samples were collected for histopathological evaluation. Vaginoscopy revealed that 41.7% of the RB cattle had abnormal vaginal secretions, while abnormal secretions were not observed in any control cow. Ultrasonographical examination of the uterus revealed the presence of free uterine fluid in 20.8% of the RB animals, while none of the control cows had fluid in the uterine lumen. In addition, ovarian cysts were observed in 25.0% of the RB animals. Histopathological evaluation of the endometrial biopsies revealed that mononuclear leukocyte infiltration, dilated uterine glands, and periglandular fibrosis were the most prevalent lesions in the sub-fertile animals. Chronic endometritis characterized by inflammatory (mononuclear leukocyte infiltration) and degenerative (dilated glands and periglandular fibrosis) endometrial lesions, and ovarian cysts were the most frequent reproductive pathologies observed in the studied subfertile Criollo Limonero cattle, suggesting a strong association with their reduced fertility.

Anatomical and histological changes of uterine horn of Aceh cattle with repeat breeding.

OBJECTIVE: This study aimed to observe the changes in anatomical pathology, histopathology, and histomorphometry of uterine horn in Aceh cattle with repeat breeding (RB). MATERIALS AND METHODS: In this study, five uterine horns were collected from fertile Aceh cattle (N1, N2, N3, N4, and N5) and Aceh cattle with RB (RB1, RB2, RB3, RB4, and RB5). Changes in the anatomical pathology of uterine horn were observed prior to histopathological preparations. The results were analyzed descriptively. RESULTS: The observation of anatomical pathology revealed that the uterus of fertile cattle was yellowish white with horn-like shape consisting of hollow muscles, while RB cattle were reddish-pale. Furthermore, uterine horn swelling with purulent exudate was observed in the uterine horn of RB1 and RB4, while swelling with serous exudates was found in RB2, RB3, and RB5. Thin-walled uterine horn with caruncular atrophy was observed only in RB3. Histopathological observations showed erosion and hyperplasia of endometrial columnar epithelial and uterine glands in RB1, RB2, RB4, and RB5. Atrophy of uterine gland was found in RB3 and edema of caruncular was observed in RB1 and RB4. In addition, hemorrhage and inflammatory cell infiltration (neutrophils, lymphocytes, and macrophages) were found in all RB cattle. Histologically, cow uterus is divided into three layers, endometrium, myometrium, and perimetrium with the uterine gland found in the endometrium. Histomorphometric measurements found that the uterine horn wall (endometrial, myometrial, and perimetrium) of RB cattle were thicker than of fertile Aceh cattle, 208.06 ± 39.90 vs. 187.39 ± 29.09 µm, 400.138 ± 51.96 vs. 277.91 ± 42.88 µm, and 23.59 ± 9.67 vs. 18.53 ± 4.40 µm. However, the endometrial gland diameter of RB cattle is smaller than that of fertile Aceh cattle, 4.04 ± 0.88 vs. 4.99 ± 1.37 µm. CONCLUSION: The changes in anatomical pathology and histopathology of the uterine horn of Aceh cattle with RB indicate endometritis which caused by subacute and chronic bacterial infections. Endometritis causes disrupted blood circulation, which is characterized by hemorrhage, edema, and thickening of the endometrium, myometrium, and perimetrium, resulting in an increased diameter of the endometrial gland in RB Aceh cattle.

Maternal variant in the upstream of FOXP3 gene on the X chromosome is associated with recurrent infertility in Japanese Black cattle.

BACKGROUND: Repeat breeding, which is defined as cattle failure to conceive after three or more inseminations in the absence of clinical abnormalities, is a substantial problem in cattle breeding. To identify maternal genetic variants of repeat breeding in Japanese Black cattle, we selected 29 repeat-breeding heifers that failed to conceive following embryo transfer (ET) and conducted a genome-wide association study (GWAS) using the traits. RESULTS: We found that a single-nucleotide polymorphism (SNP; g.92,377,635A > G) in the upstream region of the FOXP3 gene on the X chromosome was highly associated with repeat breeding and failure to conceive following ET (P = 1.51 × 10-14). FOXP3 is a master gene for differentiation of regulatory T (Treg) cells that function in pregnancy maintenance. Reporter assay results revealed that the activity of the FOXP3 promoter was lower in reporter constructs with the risk-allele than in those with the non-risk-allele by approximately 0.68 fold. These findings suggest that the variant in the upstream region of FOXP3 with the risk-allele decreased FOXP3 transcription, which in turn, could reduce the number of maternal Treg cells and lead to infertility. The frequency of the risk-allele in repeat-breeding heifers is more than that in cows, suggesting that the risk-allele could be associated with infertility in repeat-breeding heifers. CONCLUSIONS: This GWAS identified a maternal variant in the upstream region of FOXP3 that was associated with infertility in repeat-breeding Japanese Black cattle that failed to conceive using ET. The variant affected the level of FOXP3 mRNA expression. Thus, the results suggest that the risk-allele could serve as a useful marker to reduce and eliminate animals with inferior fertility in Japanese Black cattle.

Characteristics and risk factors for severe repeat-breeder female pigs and their lifetime performance in commercial breeding herds.

BACKGROUND: Repeat-breeder females increase non-productive days (NPD) and decrease herd productivity and profitability. The objectives of the present study were 1) to define severe repeat-breeder (SRB) females in commercial breeding herds, 2) to characterize the pattern of SRB occurrences across parities, 3) to examine factors associated with SRB risk, and 4) to compare lifetime reproductive performances of SRB and non-SRB females. Data included 501,855 service records and lifetime records of 93,604 breeding-female pigs in 98 Spanish herds between 2008 and 2013. An SRB female pig was defined as either a pig that had three or more returns. The 98 herds were classified into high-, intermediate- and low-performing herds based by the upper and lower 25th percentiles of the herd mean of annualized lifetime pigs weaned per sow. Multi-level mixed-effects logistic regression models with random intercept were applied to the data. RESULTS: Of 93,604 females, 1.2% of females became SRB pigs in their lifetime, with a mean SRB risk per service (± SEM) of 0.26 ± 0.01%. Risks factors for becoming an SRB pig were low parity, being first-served in summer, having a prolonged weaning-to-first-mating interval (WMI), and being in low-performing herds. For example, served gilts had 0.81% higher SRB risk than served sows (P < 0.01). Also, female pigs in a low-performing herd had 1.19% higher SRB risks than those in a high-performing herd. However, gilt age at-first-mating (P = 0.08), lactation length (P = 0.05) and number of stillborn piglets (P = 0.28) were not associated with becoming an SRB female. The SRB females had 14.4-16.4 fewer lifetime pigs born alive, 42.8-91.3 more lifetime NPD, and 2.1-2.2 lower parities at culling than non-SRB females (P < 0.05). CONCLUSIONS: We recommend that producers closely monitor the female pig groups at higher risk of becoming an SRB.

Endometrial mRNA expression of prostaglandin synthase enzymes PTGS 2, PTGFS and mPTGES 1 in repeat-breeding cows with cytologically determined endometritis.

Little is known about the inflammatory response of the endometrium in repeat-breeding cows with subclinical endometritis (SE). The objective of this study was to evaluate the mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS 2), prostaglandin F2α synthase (PTGFS) and prostaglandin E2 microsomal synthase 1 (mPTGES 1) in the endometrium of repeat-breeding cows with and without SE. SE was diagnosed cytologically using the cytobrush method, with the threshold being set at 5% polymorphonuclear neutrophils. Biopsy samples were obtained from the endometrium of repeat-breeding cows with SE (n = 10) and without SE (n = 10). The mRNA expression of the synthases was evaluated using qRT-PCR. Significantly higher (P < 0.05) expression of the PTGS 2 gene was detected in the repeat breeders with SE, whereas there was no significant difference in the expression of PTGFS and mPTGES 1 mRNAs between repeatbreeding cows with SE and those without it (P > 0.05). Our study confirms that increased endometrial expression of the PTGS 2 gene is involved in the inflammatory response in repeat breeders.

Repetition of estrus is the most frequent reproductive problem after breeding in dairy cattle from Rio de Janeiro, Brazil / Repetição de estro é o problema reprodutiva mais comum em vacas leiteiras do Estado do Rio de Janeiro, Brasil

ABSTRACT: Reproductive efficiency is one of the key elements for any milk production system to be successful. In this regard, reproductive management must be planned properly and the identification of the main reproductive disorders that affect the herd is primordial for decision-making. The aim of the present study was to identify the main reproductive problems that affect dairy herds on Rio de Janeiro (RJ), Brazil. Data regarding breed, age, reproductive disorder occurrence, and breeding system were individually collected from dairy cows raised at 25 farms located at RJ. The occurrence of reproductive disorders was reported in 37% of the studied animals. Estrous repetition (76.2%) and abortion (15.6%) were the most frequent reproductive problems reported. Estrous repetition was more common in older animals (>6 years old). However, an association between abortion and age of animal was not observed, nor an association between breeding system and occurrence of abortion. The present results demonstrated that estrous repetition is the main obstacle to the reproductive efficiency in dairy herds at RJ, and that the replace of older cows by heifers is an important point within reproductive management of a dairy herd.

RESUMO: A eficiência reprodutiva é um dos principais elementos para qualquer sistema de produção de leite ser bem-sucedida. Neste contexto, o manejo reprodutivo deve ser planejado adequadamente e a identificação das principais desordens reprodutivas que afetam o rebanho é essencial para a tomada de decisão. O objetivo do presente estudo foi identificar os principais problemas reprodutivos que acometem rebanhos leiteiros no Rio de Janeiro (RJ), Brasil. Dados relacionados com a raça, idade, ocorrência de problema reprodutivo e o sistema de acasalamento foram individualmente coletados de vacas leiteiras criadas em 25 fazendas localizadas no RJ. A ocorrência de desordens reprodutivas foi relatada em 37% dos animais estudados. A repetição de estro (76,2%) e abortamento (15,6%) foram os problemas reprodutivos mais frequentemente relatados. A repetição de estro foi mais comum em animais mais velhos (>6 anos). Contudo, uma associação entre abortamento e idade do animal não foi observada, nem uma associação entre o sistema de acasalamento e a ocorrência abortamento. Os presentes resultados demonstraram que a repetição de estro é o principal obstáculo para a eficiência reprodutiva nos rebanhos leiteiros do RJ, e que a substituição de animais mais velhos por novilhas é um importante ponto dentro do manejo reprodutivo de um rebanho leiteiro.

Plasma progesterone profile and conception rate following exogenous supplementation of gonadotropin-releasing hormone, human chorionic gonadotropin, and progesterone releasing intra-vaginal device in repeat-breeder crossbred cows.

AIM: This study was designed to evaluate the effect of gonadotropin-releasing hormone (GnRH), human chorionic gonadotropin (hCG), and progesterone impregnated intra-vaginal device on progesterone profile and conception rate in repeat-breeding crossbred cows. MATERIALS AND METHODS: Repeat-breeding crossbred cows aged 3-8 years (n=32), lactating and negative to white side test were randomly divided into four groups: Group 1 (Control, n=8), Group 2 (GnRH at 10 µg i.m, n=8), Group 3 (hCG at 1500 IU i.m., n=8), and Group 4 (progesterone impregnated intra-vaginal device at 958 mg, n=8). All the treatme nts were given on 5(th) daypostbreeding and in Group 4 intra-vaginally implanted device was withdrawn on 9(th) day (i.e., implant inserted for total 4 days) of the estrous cycle. Blood samples were collected on day 0, 5, 10, 15, and day 20 of estrous cycle, and plasma was separated for progesterone estimation. RESULTS: Accessory corpus luteum was not formed in crossbred cows of Group4 and control group. However, total 6 and 8 accessory corpora lutea were found in Group 2 and Group 3, respectively. In pregnant cows, the plasma progesterone concentration increased continuously from day 0 to day 20. In non-pregnant cows, it increased from day 0 to day 15 and then declined. The conception rate on day 60 in Group 1, Group 2, Group 3, and Group 4 was 37.5%, 50%, 75%, and 37.5%, respectively. CONCLUSIONS: Treating repeat-breeder cows with hCG is effective in increasing conception rate by developing accessory corpora lutea and higher progesterone level.