Mišeikienė Ramutė, Pečiulaitienė Nijolė, Kajokienė Lina, Bižienė Renata, Morkūnienė Kristina, Marma Vilius, Tušas Saulius, Matusevičius Paulius, Wójcik Ewa, Janocha Alina, Milczarek Anna, Kučinskas Laimutis
Institute of Biology Systems and Genetic Research, Faculty of Animal Sciences, Lithuanian University of Health Sciences, Kaunas, Lithuania.
Institute of Animal Rearing Technologies, Faculty of Animal Sciences, Lithuanian University of Health Sciences, Kaunas, Lithuania.
Vet World. 2025 Jun;18(6):1581-1589. doi: 10.14202/vetworld.2025.1581-1589. Epub 2025 Jun 16.
Cholesterol deficiency (CD) in Holstein cattle, caused by a loss-of-function mutation in the () gene, is a heritable autosomal recessive condition with known implications for fat metabolism and cholesterol transport. This study aimed to investigate the effect of the CD genotype on milk yield components, cholesterol concentration, and somatic cell count (SCC) in Lithuanian Holstein cows, and to determine whether lactation number modulates these relationships.
A total of 188 cows were classified by lactation: 1 (n = 44), 2 (n = 50), 3 and 4 (n = 60), and ≥5 (n = 34). Genotyping for the mutation was conducted using allele-specific polymerase chain reaction. Milk fat, protein, lactose, and SCC were determined using LactoScope Fourier-transform infrared spectroscopy and Somascope methods, while cholesterol concentration was measured by high-performance liquid chromatography. Statistical analysis involved the Kruskal-Wallis H test due to non-normal data distribution.
The heterozygous CD genotype was identified in 17.02% of the population, with wild-type and mutant allele frequencies of 0.91 and 0.09, respectively. Non-carriers showed marginally higher fat, protein, and cholesterol levels, with a statistically significant difference in fat content (p = 0.04). When stratified by lactation, significant differences were observed for fat content in the 1 lactation group (p = 0.026), SCC in the 2 (p = 0.038), and protein content in the 3 (p = 0.030). No significant variation in milk cholesterol concentration was detected across genotype groups in any lactation group.
This study confirms the presence of the CD-associated allele in the Lithuanian Holstein population. While CD status significantly influenced milk fat percentage, its effect on other milk composition traits and SCC was limited. Parity exhibited specific but non-consistent modulating effects. Further large-scale, longitudinal studies are warranted to elucidate the physiological underpinnings of these findings.
荷斯坦奶牛中的胆固醇缺乏症（CD）由（）基因的功能丧失突变引起，是一种遗传性常染色体隐性疾病，对脂肪代谢和胆固醇转运有已知影响。本研究旨在调查CD基因型对立陶宛荷斯坦奶牛产奶量成分、胆固醇浓度和体细胞计数（SCC）的影响，并确定泌乳次数是否调节这些关系。
总共188头奶牛按泌乳情况分类：第1胎（n = 44）、第2胎（n = 50）、第3胎和第4胎（n = 60）以及≥5胎（n = 34）。使用等位基因特异性聚合酶链反应对突变进行基因分型。使用LactoScope傅里叶变换红外光谱法和Somascope方法测定乳脂肪、蛋白质、乳糖和SCC，而胆固醇浓度通过高效液相色谱法测量。由于数据分布不呈正态，统计分析采用Kruskal-Wallis H检验。
在17.02%的群体中鉴定出杂合CD基因型，野生型和突变等位基因频率分别为0.91和0.09。非携带者的脂肪、蛋白质和胆固醇水平略高，脂肪含量存在统计学显著差异（p = 0.04）。按泌乳分层时，在第1泌乳组的脂肪含量（p = 0.026）、第2泌乳组的SCC（p = 0.038）和第3泌乳组的蛋白质含量（p = 0.030）方面观察到显著差异。在任何泌乳组的基因型组中均未检测到乳胆固醇浓度的显著变化。
本研究证实在立陶宛荷斯坦牛群体中存在与CD相关的等位基因。虽然CD状态显著影响乳脂肪百分比，但其对其他乳成分性状和SCC的影响有限。胎次表现出特定但不一致的调节作用。有必要进行进一步的大规模纵向研究以阐明这些发现的生理基础。
