Effects of age and season on conception rate of Mediterranean Italian Dairy Buffalo (Bubalus bubalis) following oestrus synchronization and fixed‐time artificial insemination

Abstract

The objective of this project was to report the effects of season and age on conception rate amongst Italian Mediterranean Buffalo subjected to an Ovsynch/Resynch (O/R) reproductive management protocol. The study utilized nulliparous (heifers), primiparous buffalo cows (PBC) and multiparous buffalo cows (MBC). The primiparous and multiparous groups were subjected to the synchronization protocol throughout the entire year, but heifers were synchronized and inseminated only during the spring/summer seasons.The conception rate obtained following the OvSynch oestrus synchronization protocol, applied during spring, was 68.4% for heifers, 83.3% for PBC and 67.7% for MBC. The overall total conception rates following the complete O/R protocol were 84.27%, 94.4% and 79%. Conception rates achieved during summer were heifers 52%, PBC 47.2% and MBC 49%, whilst overall conception rates following the full O/R protocol were 72%, 69.8% and 58.2% respectively. In the autumn seasons, PBC conceived 58.9% and MBC 52.1% following initial Ovsynch, which improved to total overall conception rates of 87.5% and 78.7% following the full O/R protocol. Similarly, in the winter season, PBC experienced a conception rate of 47.5% following Ovsynch and 72.5% after a follow-up Resynch. MBC experienced 60.0% and 74.4% conception following Ovsynch and full O/R, respectively, during winter. Total conception rates during all seasons were quite acceptable following the O/R protocol. There was a significant decrease from spring to summer in conception rate for all parity groups, but heifers were not a severely affected as older buffalo cows. This finding agrees with that of other investigators indicating that heifer fertility is not as negatively impacted by long photoperiod and higher ambient temperature as that of older animals. The O/R protocol as utilized in this study is an effective means of reproductive management for dairy buffalo cows and is effective for improving fertility during out-of-season breeding.

Effectiveness of Once Used versus New CIDR in CIDR Co-synch Protocol for Resuming Reproductive Function in Anestrous Buffaloes During Low Breeding Season

“…Seasonal pattern of reproduction is one of the major reasons for reduced reproductive efficiency and production output in buffaloes (Singh et al 2000;Baruselli 2001;Nanda et al 2003;Otava et al 2021;Devkota et al 2023;Gautam et al 2024). Various environmental factors like photoperiod or day length, temperature, relative humidity and rainfall, either alone or in combination play significant roles in controlling such reproductive behavior (Das and Khan 2010;Hassaneen et al 2021).…”

“…Various hormonal protocols used in cows have been tried to enhance the reproductive performance of anestrous buffaloes during low breeding season (Barile 2005;Dhami et al 2020;Otava et al 2021;Sharma et al 2021). One of the most commonly used protocols is Co-synch which is a modified 7day (d) Ovsynch protocol where gonadotropinreleasing hormone (GnRH) is given as an initial dose followed by prostaglandin F2 alpha (PGF2α) after 7 days and second dose of GnRH approximately 3 days later at the time of artificial insemination (AI).…”

Efecto en la eficiente reproductiva mediante el uso de dos protocolos (eCG y Ovsynch) para IATF en ganado bovino tropical

“…Además, Cabrera et al (2021) expresan que, el desarrollo de protocolos para las vacas en anestro posparto permitirá la inseminación de una población de animales significativamente mayor. El propósito de este trabajo es presentar datos de estudios en los que se aplicaron métodos actuales de manipulación de ondas foliculares y ovulación por IATF sistemática en rodeos lecheros, prestando especial atención a los que se aplican actualmente en rodeos lecheros pastoriles en América del Sur (Otava et al, 2021).…”

“…Asimismo, Otava et al (2021) indican que, la necesidad de inseminar el mayor número de animales en un período relativamente corto de tiempo implica desarrollar protocolos que permitan sincronizar el retorno al estro de los vientres que resultaron vacíos a la inseminación a tiempo fijo (IATF) (Otava et al, 2021). Resultados de programas de IATF indican que es posible obtener porcentajes de preñez promedio del 50% a la primera inseminación, tanto en vacas con cría como en novillas; al respecto Bisinotto et al (2022) agregan que existen y se han aplicado protocolos para vacas con cría con los cuales resulta un incremento de los porcentajes de preñez.…”

Administration of melatonin prior to modified synchronization protocol improves the productive and reproductive efficiency of Chinese crossbred buffaloes in low breeding season

“…The resumption of ovarian activity occurs in shorter day-length periods (October-March) in tropical environmental conditions, and this period is also termed the "peak breeding period" in buffaloes (5). In contrast, the heat stress months decreased the duration and intensity of estrus and pregnancy rate in buffaloes when the temperaturehumidity index (THI) exceeded>25 in the summer season (6)(7)(8) due to alteration in endocrine milieu (9,10). Additionally, the summer climate has a noticeable effect on follicle size and number, oocyte developmental competence and blastocyst quality in buffaloes (11)(12)(13).…”