Impact of in vitro fertilization by refrigerated versus frozen buffalo semen on developmental competence of buffalo embryos

Abstract

The objective of this study was to evaluate the fertility of buffalo semen for in vitro embryo production (IVEP) by comparing the effectiveness of refrigerated versus frozen semen. Three OPU sessions were held at 30-day intervals. For oocyte fertilization three buffalo bulls were used, one per session. At each OPU-IVEP session, one ejaculate was collected and divided into two equal aliquots. Each aliquot was either refrigerated at 5ºC/24 hours or frozen. A TRIS extender containing 10% low density lipoproteins, 0.5% lecithin and 10 mM acetylcysteine was used adding 7% glycerol for freezing. Sperm motility/kinetic was evaluated by CASA and sperm membrane integrity by the hypoosmotic swelling test. The evaluations were performed at 0 h (post final dilution at 37ºC), at 4 and 24 hs post-incubation at 5ºC and post-thaw. At 24 hs incubation and immediately post thaw sperm cells were used for in vitro fertilization of buffalo oocytes equally distributed between both groups. Cleavage rates and embryo development were followed. The embryo/matured and embryo/cultured rates were 25.4 x 14.0% and 29.4 x 18.5% (P<0.05), for chilled and frozen semen, respectively. It is concluded that cooled semen can be used for in vitro embryo production in buffalo and that a better efficiency may be expected for cooled compared to frozen semen.

Evaluación de la longevidad espermática en semen de Búfalo (Bubalus bubalis) refrigerado a 5 oC

“…Pois enquanto para a criopreservação são utilizados 15-20 milhões de espermatozoides por palheta, a preservação refrigerada necessita apenas de um milhão de espermatozoides por dose inseminante. Quando o sêmen de búfalo é utilizado depois da diluição à fresco ou refrigerado até 24 horas de refrigeração as vantagens econômicas são bastante significativas, principalmente devido ao aumento na taxa de prenhez (Almeida et al, 2015(Almeida et al, , 20162021;2022).…”

“…Neste contexto, o sêmen refrigerado surge como uma alternativa para minimizar os danos causados aos espermatozoides no processo de congelamento (Almeida et al, 2020a(Almeida et al, , 2020bAlmeida et al, 2021;Almeida et al, 2022), apresentando como principais vantagens à prevenção das injúrias relacionadas ao processo de congelação, garantindo uma maior viabilidade espermática que por sua vez permite a redução da dose de sêmen (Bucher et al, 2009), otimização de reprodutores de alto mérito genético que possuem baixa resistência ao congelamento do sêmen em programas de inseminação artificial (IA), ausência de custos relacionados à estocagem e simplicidade na manipulação/utilização para IA quando comparado ao sêmen congelado (Vishwanath, 2003). Assim como ser utilizado em cios naturais, induzidos ou não como em programas de inseminação artificial em tempo fixo (IATF), permitindo inseminar neste caso um grande número de vacas em dia e hora pré-determinada, sem a necessidade de observação de cio (Almeida et al, 2021;Baruselli et al, 2004).…”

Factors affecting the in vitro embryo production in buffalo (Bubalus bubalis): A review

“…Soliman et al (2018a) obtained a higher blastocyst rate when using fresh semen for IVF than cryopreserved semen during IVEP in buffaloes. Recently, Almeida et al (2020) obtained better results during IVF in buffaloes while using chilled (for 24 h at 5 °C) semen than cryopreserved semen.…”

Comparing in vitro maturation rates in buffalo and cattle oocytes and evaluating the effect of cAMP modulators on maturation and subsequent developmental competence

“…In vitro embryo production (IVEP) efficiency in buffalo is lower than in cattle, according to research, and this could be improved further by selecting highquality oocytes and/or improving the in vitro embryo culture system [3] [4] [5] [6]. The lack of synchronization between nuclear and cytoplasmic maturation, as well as insufficient cytoplasmic maturation, results in oocytes matured in vitro having lower developmental competence than those matured in vivo [3,4,6,7]. Despite extensive research into factors affecting oocyte maturation in mice and other animals, the molecular mechanism governing oocyte maturation in buffalo remains unknown [8][9][10][11].…”