Rosales-Martínez Froylan, Becerril-Pérez Carlos Miguel, Rosendo-Ponce Adalberto, Riaño-Gaya Alberto, Cortez-Romero César, Gallegos-Sánchez Jaime, Romo-García Salvador
Facultad Maya de Estudios Agropecuarios, Universidad Autónoma de Chiapas, Catazajá C.P. 29980, Chiapas, Mexico.
Colegio de Postgraduados, Programa de Agroecosistemas Tropicales, Campus Veracruz, Manlio Fabio Altamirano C.P. 94251, Veracruz, Mexico.
Animals (Basel). 2024 Jun 29;14(13):1922. doi: 10.3390/ani14131922.
One of the main factors that influences the fertility of cattle in grazing systems in hot tropical climates is heat stress. The objective of this study was to evaluate the effect of season, breed, hormonal and physiological condition on the quantity and quality of cumulus-oocyte complexes (COCs) and embryos produced in vitro, from Romosinuano (RM) and Tropical Milking (TM) donors. Three ovum pick-up and in vitro fertilization (OPU-IVF) were performed, one per season: hot dry (HD; 10, 10), hot humid (HH; 9, 9) and fresh dry (FD; 7, 10) in RM and LT donors. Serum levels of cortisol, insulin and glucose were measured, in addition to heart rate (HR), respiratory rate (RR) and rectal temperature (RT). Effect of season x genotype interaction ( ≤ 0.05) was observed in all COC variables and only in cleavage embryos (CLI) ( ≤ 0.05). Body weight (BW) affected all COC variables ( ≤ 0.01), except unviable (UNV) although affected degenerated embryos (DEG) ( ≤ 0.01) and total blastocysts (BLAST) ( ≤ 0.01). Cow age only affected viable COCs (VIAB) ( ≤ 0.05), code one blastocysts (BC1) and BLAST ( ≤ 0.01). Cortisol affected total COCs (COCsT), VIAB and total matured in vitro (TMIV) ( ≤ 0.01), as well as CLI, BC1 ( ≤ 0.01) and BLAST ( ≤ 0.05). Insulin affected COCsT ( ≤ 0.01), UNV ( ≤ 0.05), denuded oocytes (DE) ( ≤ 0.01), BC1 and code two blastocysts (BC2) ( ≤ 0.01). Glucose affected all COC variables ( ≤ 0.01), except UNV and all embryo variables except BC2. HR affected COCsT, DE, TMIV ( ≤ 0.01), CLI, BLAST and DEG ( ≤ 0.05). RR affected COCsT, UNV, VIAB, CLI ( ≤ 0.05), BC1, BLAST and DEG ( ≤ 0.01). RT only affected DE, VIAB ( ≤ 0.01) and BLAST ( ≤ 0.05). The seasonal climatic year variation of Veracruz and changes in physiological and hormonal variables have diverse effects on the cumulus-oocyte complexes and embryos produced by RM and TM donors.
在炎热的热带气候下，影响放牧系统中母牛繁殖力的主要因素之一是热应激。本研究的目的是评估季节、品种、激素和生理状况对来自罗莫辛努阿诺（RM）和热带泌乳（TM）供体的卵丘-卵母细胞复合体（COC）数量和质量以及体外产生的胚胎的影响。进行了三次采卵和体外受精（OPU-IVF），每个季节进行一次：RM和LT供体在炎热干燥（HD；10,10）、炎热潮湿（HH；9,9）和新鲜干燥（FD；7,10）季节。除了心率（HR）、呼吸频率（RR）和直肠温度（RT）外，还测量了皮质醇、胰岛素和葡萄糖的血清水平。在所有COC变量以及仅在分裂胚胎（CLI）中观察到季节x基因型相互作用的影响（≤0.05）。体重（BW）影响所有COC变量（≤0.01），除了不可行的（UNV），尽管影响退化胚胎（DEG）（≤0.01）和总囊胚（BLAST）（≤0.01）。母牛年龄仅影响可行的COC（VIAB）（≤0.05）、1级囊胚（BC1）和BLAST（≤0.01）。皮质醇影响总COC（COCsT）、VIAB和体外总成熟（TMIV）（≤0.01），以及CLI、BC1（≤0.01）和BLAST（≤0.05）。胰岛素影响COCsT（≤0.01）、UNV（≤0.05）、裸卵（DE）（≤0.01）、BC1和2级囊胚（BC2）（≤0.01）。葡萄糖影响所有COC变量（≤0.01），除了UNV，以及除BC2外的所有胚胎变量。HR影响COCsT、DE、TMIV（≤0.01）、CLI、BLAST和DEG（≤0.05）。RR影响COCsT、UNV、VIAB、CLI（≤0.05）、BC1、BLAST和DEG（≤0.01）。RT仅影响DE、VIAB（≤0.01）和BLAST（≤0.05）。韦拉克鲁斯的季节性气候年变化以及生理和激素变量的变化对RM和TM供体产生的卵丘-卵母细胞复合体和胚胎有不同影响。
