Incidence of postpartum anestrus among buffaloes in and around Jabalpur

Effect of prostaglandin treatment on the estrus behaviour, follicular and luteal morphometry and serum hormone profile in sub-estrus buffaloes during non-breeding season

Sub-estrus buffaloes do not exhibit estrus signs despite being cyclic contributing to extended service periods and inter-calving intervals causing significant economic loss. The present study described the effect of synthetic prostaglandin (PGF2α) on estrus behaviour, follicular and luteal morphometry, and serum estradiol (E2) and progesterone (P4) profile in sub-estrus buffaloes during the non-breeding season. The incidence of sub-estrus was 38.4% during the non-breeding season. The sub-estrus buffaloes (n = 33) were divided into two groups, viz., Control (n = 16) and PGF2α treatment (Inj. Cloprostenol 500 μg, i.m., n = 17). Estrus induction response was significantly greater in the treatment (100 vs. 18.75%, p < .001), and a relatively greater proportion of animals conceived in the treatment group (29.41 vs. 6.25%, p = .08). The time elapsed to induction of estrus and insemination following treatment was significantly lower in the treatment group than control. A significant increment in the follicle diameter (9.72 ± 0.45 vs. 13.00 ± 0.45 mm, P < .0001) and serum estradiol (E2) concentration (66.01 ± 11.92 vs. 104.9 ± 13.21 pg/mL, p = .003) observed at the post-treatment period in the PGF2α treatment group. At the same time, CL diameter was reduced significantly at a higher regression rate in the PGF2α treated buffaloes than those of control. Of the responded buffaloes, only 30% showed high-intensity estrus attributed to the expulsion of cervico-vaginal mucus (CVM), uterine tonicity, micturition, and mounting response by a teaser bull. From this study, it can be concluded that the administration of PGF2α could induce estrus in the sub-estrus buffaloes during the non-breeding season. Behavioural changes, along with sonographic observation of POF, regressing CL, and serum E2 and P4 concentration would be useful to determine the right time of insemination in sub-estrus buffaloes during non-breeding season.

Mucin and salt combination simulate typical fern-like pattern of buffalo saliva smear at estrus

Estrus detection in buffaloes primarily relies on behavioral and physiological signs. Especially during summer, these signs are less prominent to recognize. Thus, estrus detection is a pronounced challenge within the realm of buffalo husbandry, particularly in the summer. Therefore, a simple and accurate estrus detection method is required for buffalo farmers. The observation of fern-like salivary crystallization patterns is one such simple method to detect estrus in buffaloes, bactrian camels, beagle bitches, and cows. However, the exact mechanism for the formation of typical fern-like is not known. We hypothesized that it might be because of the estrus-specific mucins and salts. To test this hypothesis, we prepared the smears by combining different concentrations of mucin type -2 (MUC2) and -3 (MUC3) with sodium chloride (NaCl). Microscopic examination confirmed that fern-like patterns resulted from a combination of the MUC3 and NaCl produced more realistic fern patterns than that of MUC2 or BSA with salt. To predict possible mucin and salt concentration showing natural fern-like patterns at the estrus stage in buffalo saliva, we constructed a guide tree of artificially generated fern-like patterns using an image analysis online tool. This computation analysis revealed that most of the natural buffalo estrus saliva samples showing typical fern-like patterns clustered in the cluster 2 of the guide tree comprising of 13 clusters. In the cluster 2, MUC3 in combination with the salt concentrations of 100, 150, and 250 mM was commonly found in a close proximity to the natural typical fern-like patterns of saliva smear of buffaloes at estrus. Conclusively, the buffalo saliva at estrus is predicted to have a gel-forming heavily glycosylated protein such as mucin along with at least 100 mM of NaCl. RESEARCH HIGHLIGHTS: Glycoprotein and salts combination replicates fern-like pattern of buffalo saliva at estrus. MUC3 and NaCl salt combination produces more realistic fern-like patterns compared with MUC2 or BSA and salt combination. MUC3 with NaCl at 100, 150, and 250 mM consistently resembled natural estrus saliva fern-like patterns. During estrus, buffalo saliva is expected to contain heavily glycosylated mucin and at least of 100 mM NaCl.

New insights into semen separation techniques in buffaloes

Male infertility is frequently caused by idiopathic or unexplained reasons, resulting in an increase in demand for assisted reproductive technologies. In buffaloes, more than in other animals due to reproductive hardiness, successful fertilization needs spermatozoa to effectively transit the female reproductive system to reach the oocyte. This mechanism naturally picks high-quality sperm cells for conception, but when artificial reproductive technologies such as in vitro fertilization, intracytoplasmic sperm injection, or intrauterine insemination are utilized, alternative techniques of sperm selection are necessary. Currently, technology allows for sperm sorting based on motility, maturity, the lack of apoptotic components, proper morphology, and even sex. This study provides current knowledge on all known techniques of sperm cell sorting in buffaloes, evaluates their efficiency, and discusses the benefits and drawbacks of each approach.

A single nucleotide polymorphism of the thyrotropin releasing hormone degrading ectoenzyme (TRHDE) gene is associated with post-partum anestrus in Murrah buffalo

Thyrotropin releasing hormone degrading enzyme (TRHDE) gene is implicated in Thyrotropin releasing hormone (TRH) mediated prolactin secretion. It has been shown that the prolactin secretion alters the Gonadotropin-releasinghormone(GnRH) mediated estrous cycle. Therefore, TRHDE may also regulate postpartum anestrus. Earlier studies reported the role of non-synonymous single nucleotide polymorphism (SNPs) in various pathophysiological conditions by altering the structure and function of the proteins. Hence, in the present study, we identified SNPs in the putative promoter, first exon, middle exon and 3'-UTR containing the last exon of TRHDE gene and determined their association with postpartum anestrus (PPA) in Murrah buffaloes. We found one non synonymous SNP (G > C at 118095875 bp on chromosome 4) in the first exon of TRHDE and performed its association analysis in a population sample of 50 extreme PPA (residual PPAI: 123.06 ± 12.98 days) and 50 normal (residual PPAI: -80.46 ± 3.19 days) buffaloes. The residual PPAI value was the observed PPAI adjusted for the effect of 38 non-genetic factors. The analysis showed a significant (P < 0.004167) association of this SNP with PPA in buffaloes. Molecular dynamics simulations (MDS) also supported that the C allele altering Glutamine to Histidine at the amino acid 148 of TRHDE could enhance the stability and rigidity of TRHDE protein, which may lower its activity, increase TRH and prolactin, and reduce GnRH in PPA buffaloes. The MDS analysis further strengthens the association of the SNP (G > C) in the TRHDE gene with PPA condition in Murrah buffaloes. However, further investigation is needed to prove the MDS observations.

Salivary TIMP1 and predicted mir-141, possible transcript biomarkers for estrus in the buffalo (Bubalus bubalis)

Successful reproductive management of buffaloes depends primarily upon timely estrus identification. However, 50% of the estrus events are undetected in buffaloes with the available estrus identification methods, leading to huge financial loss to buffalo farmers. Hence, there is an urgent need to develop an alternative and accurate estrus identification method, particularly on the basis of biomarkers in non-invasive fluids. Thus, the present study aimed to identify RNA based estrus biomarkers in cell free saliva in Bubalus bubalis, so that they can be used for future field applicable RT-LAMP colour reactions. RNA-Seq analysis of cell free salivary RNA showed 49 differentially abundant mRNAs between the estrus and diestrus stages. Among five mature miRNAs predicted from the RNA-Seq data, four were found differentially altered at the estrus stage than the diestrus stage. Validation study by direct salivary transcript analysis (DSTA) on 6 selected mRNAs (PPARGC1a, TIMP1, PEBP4, CSPG5, PRHR and ATOH7) and 5 miRNAs (bta-miR-92b, bta-miR-302d, bta-miR-141, bta-miR-27a and bta-let-7a-5p) showed significantly higher levels of TIMP1 (3.46 fold; P < 0.5) and bta-mir-141 (1.33 fold; P < 0.5) in cell-free saliva at the estrus stage compared to the diestrus stage. Hence, TIMP1 and miR-141 appear to be the possible transcript biomarkers for estrus in the cell free saliva of the buffalo. However, further validation studies are required in a large population of buffaloes to determine their estrus biomarker potential before considering them for RT-LAMP colour reaction.

Validation of salivary ferning based estrus identification method in a large population of water buffaloes (Bubalus bubalis) using Foldscope

Missing an estrus event is an economic problem in buffaloes because of lack of a simple and accurate estrus identification method. Saliva, a non-invasive fluid available every time, showed typical fern-like crystallization patterns at early estrus in buffaloes. However, to implement this salivary ferning based estrus identification method in the field conditions, the present study, for the first time, validated this method in four buffalo population samples (PS) representing four different field scenarios, an organized herd (PS1, 10 buffaloes monitored daily for a year (149 estrus events)), artificial insemination (AI) centers (PS2, 114 buffaloes brought for AI), induced estrus condition (PS3, 44 buffaloes) and farmers' doorsteps (PS4, 275 random buffaloes with unknown reproductive history and no estrous signs). Totally, 582 saliva samples were collected from 443 buffaloes. Salivary smears were observed under a simple microscope and/or a less expensive (< 1USD) paper microscope, Foldscope. On the basis of salivary fern-like patterns, the proportions of estrus identification were significantly different among PS. Specifically, the proportions in the PS1 (0.74, P < 0.0001) and PS4 (0.08, P < 0.05) were significantly higher than their population proportion estimates, 0.5 and zero, respectively. Therefore, this estrus identification method is much useful in the PS1 and PS4, the practical field scenarios requiring an accurate estrus prediction method, compared to the PS2 and PS3. Especially, this method is 91 % confirmatory to detect early estrus in PS4. Therefore, salivary ferning is a useful technique to identify early estrus in buffaloes in the field conditions at farmers' doorsteps.

Association of taurine with ovarian follicular steroids and postpartum anestrus condition in Murrah buffaloes

Taurine is an abundant intracellular beta-amino acid majorly synthesized in the liver and transported through plasma. In mammals, taurine was reported to be involved in various physiological functions, including the enhancement of testosterone levels, the major estradiol precursor. Therefore, we hypothesize that taurine levels are associated with ovarian follicular steroids as well as with a reproductive problem called postpartum anestrus (PPA) in dairy buffaloes. To understand the taurine levels and its possible role in buffalo ovarian follicles, a correlation was established among taurine, estradiol, and testosterone levels in the ovarian follicular fluid. For this purpose, buffalo ovaries were obtained from the slaughterhouse, and follicular fluid samples were collected from small (<4 mm), medium (4-8 mm) and large (>8 mm) follicles. Taurine and steroid levels in the follicular fluid were analyzed by TLC and ELISA, respectively. Taurine and testosterone levels were significantly (P < 0.05) higher in the follicular fluid of small and medium follicles than large follicles, whereas the estradiol levels were significantly (P < 0.001) higher in the large follicles. Thus, taurine showed a positive correlation (r = 0.75) with testosterone and a negative correlation (r = -0.77) with estradiol in buffalo follicular fluid, indicating its possible role in testosterone function during follicular development. Interestingly, significantly (P < 0.001) lower plasma taurine levels in PPA (n = 50) than normal cyclic (n = 50) buffaloes represented its association with PPA. Therefore, our present study recommends the need for future nutrition studies on taurine supplementation to PPA buffaloes.

Salivary miR-16, miR-191 and miR-223: intuitive indicators of dominant ovarian follicles in buffaloes

Estrus or sexual receptivity determination is utmost important for efficient breeding programs for female buffaloes. Prominent estrus behavioral symptoms are the result of several molecular and neuroendocrine events involving the ovary and the brain. Expression of estrus behavior is poor in buffaloes during the summer season. Hence, the discovery of biomarkers specific to the estrus stage or its related ovarian events, like the presence of dominant ovarian follicle, is helpful for developing an easy estrus determination method. MicroRNA are small non-coding RNA with a potential to be biomarkers. Therefore, the present study targeted to investigate the potential of estrogen responsive miRNAs (miR-24, miR-200c, miR-16, miR-191, miR-223 and miR-203) as estrus biomarkers in buffalo saliva, a non-invasive fluid representing animals' pathophysiology. There was a significant (P < 0.05) increase in the salivary presence of the miR-16, miR-191 and miR-223 at 6th and 18th-19th days than the 0 day (estrus), 10th day and the following consecutive estrus day. These observations may indicate an association between the representative lower presence of these miRNA in saliva and the presence of dominant ovarian follicles. To test this association, pathway analysis, target gene identification, functional annotation and protein-protein interaction networks (PPI) were performed for miR-16, miR-191 and miR-223 by different bioinformatics tools. Interestingly, the top pathways (fatty acid biosynthesis and oocyte meiosis), target genes (FGF, BDNF and IGF1) and PPI hub genes (KRAS, BCL2 and IGF1) of these miRNAs were found essential for ovarian follicular dominance. In conclusion, the miR-16, miR-191 and miR-223 may not be the perfect estrus stage-specific biomarkers. However, their lower presence in saliva at estrus and 9th-10th day of estrous cycles, when the ovary usually has a dominant follicle in buffaloes, may intuitively indicate the follicular dominance. Further studies are needed to prove this association in a large population.

A comparative therapeutic management of anoestrus in buffaloes using insulin and GnRH

Aim:

Anoestrus is one of the most common functional disorders of the reproductive cycle in buffaloes. In spite of technical advancement, there is no single cure for the management of anoestrus. Therefore, the aim of this study was to find out the efficacy of gonadotropic releasing hormone (GnRH) and metabolic hormone for the management of true anoestrus in buffaloes.

Materials and Methods:

The experimental animals were selected on the basis of history, gyneco-clinical examinations and progesterone estimation. Deworming was done with Fenbendazole and thereafter mineral mixture was given @ 50 g per animal per day for 10 days in all the selected buffaloes before the start of treatment. The selected buffaloes were randomly divided into four groups (n=25). In Group I, buffaloes were administered 20 µg of buserelin intramuscularly. Buffaloes of Group II were administered long-acting insulin @ 0.25 IU/Kg body weight subcutaneously for 5 consecutive days. In Group III, buffaloes were treated with a combination of insulin and buserelin in the above-mentioned doses whereas buffaloes of Group IV were kept as untreated control.

Results:

The higher oestrus induction (64% vs. 28%) was found in Group III and differed significantly (p<0.05) as compared to control group. The conception rate (69.23% vs. 66.66%) was also found higher in Group III but did not differ significantly among the treated groups. The mean time taken for the onset of oestrus was recorded significantly shorter in insulin (8.80±0.69) and GnRH (7.60±0.92 days) alone and as compared to other (Group III, 14.43±0.83 and Group IV, 20.57±1.69 days) groups.

Conclusion:

The results of this study indicated better fertility response using Insulin plus Buserelin in true anoestrus buffaloes under field conditions.

Relation between antioxidant status and postpartum anestrous condition in Murrah buffalo

Aim:

Objective of the present study was to investigate the relation between antioxidant status and postpartum anestrous (PPA) condition in Murrah buffalo.

Materials and Methods:

Jugular blood samples were collected from two different groups of Murrah buffaloes each group consisting of 20 animals. Group I was of PPA and Group II were of cyclic buffaloes. The animals selected were examined for confirmation for cyclic and acyclic condition (>120 days) after calving by routine transrectal ultrasonography. Heard record was also used for cross confirmation.

Results:

The analysis of antioxidants in plasma and hemolysates revealed that the levels of vitamin E, β-carotene and reduced glutathione in plasma and superoxide dismutase (SOD) in hemolysate were significantly higher in cyclic animals than PPA animals. The levels of vitamin C, SOD and glutathione peroxidase in plasma did not show any significant difference among the two groups studied. The low antioxidant level in affected animals may predispose them toward PPA condition.

Conclusion:

Stress imposed by pregnancy and lactation affected the reproductive performance in PPA animals which might be inherently more susceptible to these stressors than those who were normal cyclic as all the animals were maintained under similar feeding and management practices.