GPGMH, a New Fixed Timed-AI Synchronization Regimen for Swamp and River Crossbred Buffaloes (Bubalus bubalis)

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.

Upgrading the fixed-time artificial insemination (FTAI) protocol in Romanian buffaloes

The present study describes the challenges of assisted reproduction in Romanian buffaloes while increasing the efficacy of artificial insemination by choosing the most suitable method. The modified fixed-time artificial insemination (FTAI) protocol with sexed semen was used to increase the conception rate. This study included a total of 80 buffalo heifers that received ovarian stimulation using the OvSynch protocol. Two groups (n = 40), namely, a control group, in which the classic FTAI method was performed, and an experimental group, in which deep intrauterine AI was performed in cows that had developed a dominant follicle (US+UcFTAI), were randomly selected. The conception rate (CR) was 63.6% in the experimental group, which was statistically higher (P < 0.05) than the control group (30%). The ultrasound examination indicated that, using the OvSynch protocol, 82.5% (33 out of 40) of buffaloes developed a dominant follicle (DF) while the distribution between the warm and cold seasons was 75 and 90%, respectively. The CR was 60% during the hot season and 66.6% during the cold season. At calving, 92.5% female fetuses were born. The improved FTAI method in this study enhanced the results by reducing the waste of sexed semen and maximizing the response to OvSynch, making it a recommendation for practitioners. This study presents preliminary results and highlights that genetic progress is difficult to achieve. A systematic approach is needed in order to choose the most suitable biotechnological method for each farm.

Nasal immunization with AMH-INH-RFRP DNA vaccine for improving follicle development and fertility in buffaloes

INTRODUCTION

Inhibin DNA vaccine has already been proven to improve the fertility of animals. This study aimed to investigate the effects of a novel Anti-Müllerian hormone (AMH)-Inhibin (INH)-RF-amide-related peptides (RFRP) DNA vaccine on immune response and reproductive performance in buffalo.

METHODS

A total of 84 buffaloes were randomly divided into four groups and nasally immunized twice a day with 10 ml of either AMH-INH-RFRP DNA vaccines (3 × 10¹⁰ CFU/ml in group T1, 3 × 10⁹ CFU/ml in group T2, and 3 × 10⁸ CFU/ml in group T3) or PBS (as a control) for 3 days, respectively. All animals received a booster dose at an interval of 14 days.

RESULTS

ELISA assay revealed that primary and booster immunization significantly increased the anti-AMH, anti-INH, and anti-RFRP antibody titers in the T2 group compared with that in the T3 group. After the primary immunization, the antibody positive rate was significantly higher in the T2 group than that in the T3 group. In addition, ELISA results indicated that concentrations of E2, IFN-γ, and IL-4 were significantly higher in the antibody-positive (P) group compared to the antibody-negative (N) group. In contrast, there was no significant difference in the concentrations of P4 between the P and N groups. Ultrasonography results revealed a highly significant increase of 2.02 mm in the diameter of ovulatory follicles in the P group compared to the N group. In parallel, growth speed of dominant follicles was significantly higher in the P group than that in the N group (1.33 ± 1.30 vs 1.13 ± 0.12). Furthermore, compared to N group, the rates of oestrus, ovulation, and conception were also significantly higher in the P group.

CONCLUSION

The novel AMH-INH-RFRP DNA vaccine improves the proportion of oestrus, ovulation, and conception in buffalo by promoting the production of E2 and the growth of follicles.

Dietary Supplementation of Capsaicin Enhances Productive and Reproductive Efficiency of Chinese Crossbred Buffaloes in Low Breeding Season

The present study investigated the role of dietary capsaicin (CPS) supplementation on milk yield (liters/head) and milk composition (total solids, lactose, albumin, protein, fat, milk urea nitrogen (MUN), somatic cell count (SCC) and somatic cell score (SCS), serum metabolites (lipoprotein esterase (LPL) and aspartate aminotransferase (AST)), and reproductive physiology (follicular development, estrus response, ovulation and pregnancy) following synchronization during the low breeding season. One hundred (n = 100) crossbred buffaloes were randomly assigned to four dietary groups consisting of CPS supplementation dosages (0, 2, 4 or 6 mg/kg of total mixed ration; TMR) as CPS-0 (n = 26), CPS-2 (n = 22), CPS-4 (n = 25) and CPS-6 (n = 27), respectively, in a 30-day feed trial. The results revealed that the CPS-4 group of buffaloes had a better estrus rate (72%) along with improved (p < 0.05) ovulatory follicle diameter (13.8 mm), ovulation rate (68%) and pregnancy rate (48%) compared to other treatment groups. Milk yield improved (p < 0.05) in CPS-4 supplemented buffaloes after day 20 of the trial, comparatively. There was a significant effect (p < 0.05) of milk sampling day (day 30) on total milk solids, lactose, milk protein and MUN levels, whereas lactose, MUN, SCC and SCS were influenced by supplementation dosage (CPS-4). Glucose levels were affected in buffaloes by sampling time (artificial insemination (AI) and 50-day post-AI) and CPS-dose (CPS-4 and CPS-6), respectively. LPL level changed in CPS-2 and CPS-4 groups at AI time and 50 days after AI. In addition, the AST level was different in CPS-4 at AI time and 50 days after AI. Therefore, our data suggest that a medium dose (~4 mg/kg of TMR) of CPS provided a better response in the form of milk yield, milk composition, serum metabolites and reproductive performance in crossbred buffaloes during the low breeding season.

Effect of Different Synchronization Regimens on Reproductive Variables of Crossbred (Swamp × Riverine) Nulliparous and Multiparous Buffaloes during Peak and Low Breeding Seasons

Simple Summary

Parity and season are two prominent variants which influence buffalo reproductive performance and synchronization outcome. The present study compared modified new Ovsynch synchronization (GPGMH) protocol with conventional Ovsynch (OVS) in reproductive parameters of buffaloes with different parity (nulliparous and multiparous) in different seasons (peak and low breeding seasons). Compared to the conventional Ovsynch, the modified GPGMH protocol was more effective to enhance the estrus rate, ovulation rate and pregnancy rate in multiparous crossbred buffaloes. In addition, the application of GPGMH protocol improve the reproductive performance during the peak breeding season than low breeding season.

Abstract

The present study was conducted to examine the effect of conventional the Ovsynch protocol (OVS) and a modified Ovsynch synchronization (GPGMH) protocol on the follicular dynamics, estrus, ovulation, and pregnancy in nulliparous and multiparous crossbred (swamp × riverine) buffaloes during different seasons. GPGMH or OVS protocols were used to synchronize nulliparous (n = 128; GPGMH = 94, OVS = 34) and multiparous (n = 154; GPGMH = 122, OVS = 32) buffaloes during the peak (n = 186; GPGMH = 143, OVS = 43) and low breeding (n = 96; GPGMH = 73, OVS = 23) seasons. Buffaloes were monitored for follicular dynamics, estrus response, ovulation, and pregnancy rates. The results showed that protocol, parity, and season had significant effects on estrus, ovulation, and pregnancy variables, and interactions among parity and protocol, season and protocol, and season and parity were observed for few of reproductive indices in the crossbred buffaloes. There were no significant (p > 0.05) interaction for protocol, parity and season. In multiparous buffaloes, the application of the GPGMH protocol significantly (p < 0.05) increased the interaction to the interval to estrus onset after the second GnRH, estrus response, ovulation rate, and pregnancy rate, and lowered (p < 0.05) the silent estrus when compared with the conventional OVS protocol. During the peak breeding season, the application of the GPGMH protocol significantly (p < 0.05) improved the interaction to the estrus response, ovulation rate, and pregnancy rate, while it lowered (p < 0.05) the silent estrus incidence when compared to the conventional OVS protocol. In conclusion, the GPGMH protocol, in comparison to the OVS protocol, improves the follicular dynamics, estrus response, ovulation, and pregnancy rates in crossbred multiparous buffaloes during the peak breeding seasons.