The in vitro embryo production industry in the actual world presents some difficulties related to low embryonic production rates, a problem that could be associated with in vitro culture conditions that differed from the in vivo (oviductal) conditions, mainly related to cytoplasmic lipid accumulation. L-carnitine is known as a modulator of β-oxidation in the developing embryo, as it has been demonstrated that it improves embryo quality without affecting the in vitro embryo production rate. The aim of the present work was to evaluate the effect of L-carnitine supplemented during the in vitro maturation and culture processes on the implantation rate of in vitro produced embryos. Supplementation with 3.8 mM of L-carnitine was used during in vitro maturation, and later, during late in vitro culture, it was added at 1.5 mM. A control group contained no L-carnitine supplementation. Bovine oocytes obtained by ultrasound-guided follicle aspiration from healthy Bos taurus indicus cows were matured, fertilized and cultured in vitro. Multiparous F1 (Bos taurus taurus × Bos taurus indicus) cows were used as recipients. Overall, 460 oocytes were processed in three independent replicates from in vitro maturation until day 8 of the in vitro culture. No significant difference was found between treatments of in vitro embryo production. However, pregnancy rate at days 45 and 72 was significantly higher in blastocysts derived from L-carnitine treatment (31.55 ± 9.78%) compared to the control group (18.68 ± 6.31%). In conclusion, addition of L-carnitine at 3.8 mM and 1.5 mM in the maturation, and culture medium after day 3 of in vitro production process, significantly improved pregnancy rate after embryo transfer.

中文翻译：

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在培养基中补充左旋肉碱可提高体外培养的带有金牛（Bos taurus indicus）母牛有性精液的胚胎的怀孕率。

现实世界中的体外胚胎生产行业存在一些与低胚胎生产率相关的困难，这可能与体外培养条件与体内（输卵管）条件不同有关，主要与细胞质脂质的积累有关。左旋肉碱在发育中的胚胎中被称为β-氧化的调节剂，因为已证明其可提高胚胎质量而不影响体外胚胎的产生速率。本工作的目的是评估在体外成熟和培养过程中补充的左旋肉碱对体外产生的胚胎着床率的影响。在体外成熟过程中使用了3.8 mM的L-肉碱补充，后来在体外培养的后期，以1.5 mM的量添加了L-肉碱。对照组不含左旋肉碱补充剂。通过超声引导从健康的Bos taurus indicus牛滤泡吸取获得的牛卵母细胞进行成熟，受精和体外培养。使用多头F1（Bos taurus taurus×Bos taurus indicus）牛作为受体。总体上，从体外成熟到体外培养的第8天，以三个独立的重复方式处理了460个卵母细胞。在体外胚胎生产的处理之间没有发现显着差异。然而，与对照组（18.68±6.31％）相比，左旋肉碱治疗的胚泡在第45天和第72天的​​妊娠率显着更高（31.55±9.78％）。总之，在成熟过程中添加3.8 mM和1.5 mM的L-肉碱，以及体外生产过程第3天后的培养基，