Toralová Tereza, Ducháček Jaromír, Gašparík Matúš, Kinterová Veronika, Marešová Nikola, Codl Radim, Stádník Luděk
Laboratory of Developmental Biology, Institute of Animal Physiology and Genetics CAS, Liběchov, Czech Republic.
Department of Animal Science, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czech Republic.
J Anim Sci. 2025 Jan 4;103. doi: 10.1093/jas/skaf276.
Metabolic stress and negative energy balance (NEB) are typical undesirable accompanying phenomena of the postpartum period in dairy cattle. They negatively affect not only milk production but also the reproductive abilities of the cow, and it is therefore desirable to recognize NEB early to prevent its development. Metabolic stress markers are traditionally total cholesterol (tChol), nonesterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), and triacylglycerols (TAGs). The aim of this work was to determine whether the level of the aforementioned markers in the blood correlates with the ability of a primiparous dairy cow to conceive soon after the first calving. Therefore, oocytes were collected from the monitored cows shortly after calving using the ovum pick-up method, and their quality was subsequently determined. We observed cumulus cell expansion, oocytes quality, maturation rate, and the amount and distribution of lipids within the oocyte. In addition to the mentioned markers, we also monitored the effect of the season in which aspiration was performed to assess its impact on the reproductive indicators of the monitored cows. We observed a negative correlation between higher TAGs and oocyte maturation rate, while the number of aspirated oocytes per cow and the fertilization capability were positively associated with TAGs. Additionally, higher BHB levels in the blood were linked to enhanced fertilization capability. The higher levels of TAGs, BHB, and NEFA in blood were associated with increased lipid intensity, and higher lipid content was positively correlated with both the quality of cumulus cells and oocytes. In summary, we found that NEFA, BHB, and TAGs are the most reliable markers of a cow's readiness to become pregnant after her first calving. The use of tChol, however, remains very controversial. Moreover, primiparous cows are more prepared for re-pregnancy in the warmer season.
代谢应激和负能量平衡（NEB）是奶牛产后典型的不良伴随现象。它们不仅对产奶量有负面影响，还会影响奶牛的繁殖能力，因此尽早识别负能量平衡以防止其发展是很有必要的。传统上，代谢应激标志物包括总胆固醇（tChol）、非酯化脂肪酸（NEFA）、β-羟基丁酸（BHB）和三酰甘油（TAGs）。这项工作的目的是确定上述血液标志物水平是否与初产奶牛首次产犊后不久受孕的能力相关。因此，在产犊后不久使用采卵方法从监测的奶牛中采集卵母细胞，随后确定其质量。我们观察了卵丘细胞扩展、卵母细胞质量、成熟率以及卵母细胞内脂质的数量和分布。除了上述标志物外，我们还监测了采卵季节的影响，以评估其对监测奶牛繁殖指标的影响。我们观察到较高的TAGs与卵母细胞成熟率之间呈负相关，而每头奶牛采集的卵母细胞数量和受精能力与TAGs呈正相关。此外，血液中较高的BHB水平与受精能力增强有关。血液中较高水平的TAGs、BHB和NEFA与脂质强度增加有关，较高的脂质含量与卵丘细胞和卵母细胞的质量均呈正相关。总之，我们发现NEFA、BHB和TAGs是奶牛首次产犊后受孕准备情况最可靠的标志物。然而，tChol的使用仍然存在很大争议。此外，初产奶牛在温暖季节更准备好再次怀孕。
