Zhang Hang, Ao Changjin, Dan Ni
College of Animal Science and Technology, Inner Mongolia Minzu University, Tong Liao, Inner Mongolia, China.
College of Animal Science, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, China.
Front Vet Sci. 2025 Mar 26;12:1469169. doi: 10.3389/fvets.2025.1469169. eCollection 2025.
This study was designed to determine the effects of diets containing different-quality forages and concentrate content on milk composition and lipogenic enzyme expression in the mammary glands of dairy cows using RNA sequencing.
Thirty Holstein cows were randomly assigned to one of three treatments: mixed forage consisted of hay, silage, and alfalfa forage to a concentrate ratio of 54:46 (MF); corn stover as forage and forage to a concentrate ratio of 35:65 (CSA); corn stover as forage and forage to a concentrate ratio the same as MF (CSB). Mammary tissue biopsies were performed to analyze lipogenic enzyme expression using RNA-seq.
Treatments did not affect dry matter intake, milk protein, or lactose. The milk yield, fat content and saturated fatty acids (SFAs), and short- and medium-chain fatty acids (SMFAs) contents were lower in CSA and CSB than in MF. Still, the unsaturated FA and long-chain FA contents were higher than in MF. We used RNA-seq to compare analyses of three groups of mammary tissue in transcriptomics, Gene Ontology and KEGG-enriched pathways. Differentially expressed genes (DEGs) involved in lipid metabolic pathways and the FA biosynthesis pathway in MF were significantly higher than in CSB. In contrast, DEGs of FA extension and unsaturated FA synthesis pathway were significantly lower than in CSB.
Corn stover as a forage diet reduced the milk yield, fat content, SMFAs, SFAs, and the gene expression of mammary lipogenic enzymes in dairy cows.
本研究旨在通过RNA测序确定含有不同质量草料和精料含量的日粮对奶牛乳腺中乳成分和生脂酶表达的影响。
30头荷斯坦奶牛被随机分配到三种处理之一：混合草料由干草、青贮饲料和苜蓿草料组成，精料比为54:46（MF）；以玉米秸秆为草料，草料与精料比为35:65（CSA）；以玉米秸秆为草料，草料与精料比与MF相同（CSB）。进行乳腺组织活检以使用RNA-seq分析生脂酶表达。
处理对干物质摄入量、乳蛋白或乳糖没有影响。CSA和CSB组的产奶量、脂肪含量、饱和脂肪酸（SFA）以及短链和中链脂肪酸（SMFA）含量均低于MF组。不过，不饱和脂肪酸和长链脂肪酸含量高于MF组。我们使用RNA-seq对三组乳腺组织进行转录组学、基因本体论和KEGG富集途径的比较分析。MF组中参与脂质代谢途径和脂肪酸生物合成途径的差异表达基因（DEG）显著高于CSB组。相比之下，脂肪酸延伸和不饱和脂肪酸合成途径的DEG显著低于CSB组。
以玉米秸秆为草料的日粮降低了奶牛的产奶量、脂肪含量、SMFA、SFA以及乳腺生脂酶的基因表达。
