Effects of Artemisia ordosica Krasch on growth, hypothalamic appetite-regulating genes and lipid metabolism of lambs in cold weather

This experiment investigated the effects of 3% Artemisia ordosica Krasch (AOK) on growth, hematological profiles, hypothalamic appetite-regulating genes and lipid metabolism in lambs during a 6–week cold season feeding trial. Eighteen male lambs, five months of age (Australian White × Small-tail Han), with similar body weights (26.98 ± 2.40 kg), were selected and randomly divided into three groups. The control group (CON) was housed under ‌an‌ artificially controlled temperature, while the cold stress group (CS) was exposed to ‌the‌ natural low-temperature environment‌.‌ The AOK group, which was ‌similarly exposed to the cold environment‌, received a basal diet with 3% AOK substituted for the roughage. The apparent phosphorus digestibility in the AOK group was significantly higher than that in the CON and CS groups (p = 0.01). On day 14, the AOK group exhibited higher levels of haemoglobin (p = 0.03) and mean corpuscular volume (p = 0.02) compared to the CS group. ‌The relative expression levels of pro-opiomelanocortin genes in the hypothalamus of the AOK group were lower than those in the CON and CS groups. Conversely, ‌mechanistic target of rapamycin‌ relative expression was higher in the AOK group compared to the CON and CS groups. AMP-activated protein kinase‌ genes in the CS group were higher than those in the CON and AOK groups. The metabolomic analysis revealed that AOK regulates perirenal adipose tissue by upregulating triglycerides and downregulating acylcarnitine levels. Feeding AOK markedly altered perirenal adipose tissue lipid profiles. In conclusion, feeding AOK during cold exposure has a potential role in maintaining homeostasis in lambs. Dietary supplementation with 3% Artemisia ordosica Krasch did not improve the growth performance of lambs under low-temperature conditions, but it increased the digestibility of phosphorus.Dietary Artemisia ordosica Krasch supplementation enhanced blood oxygen transport capacity, modulated hypothalamic appetite and energy-sensing pathways, and markedly altered perirenal adipose tissue lipid profiles. Dietary supplementation with 3% Artemisia ordosica Krasch did not improve the growth performance of lambs under low-temperature conditions, but it increased the digestibility of phosphorus. Dietary Artemisia ordosica Krasch supplementation enhanced blood oxygen transport capacity, modulated hypothalamic appetite and energy-sensing pathways, and markedly altered perirenal adipose tissue lipid profiles.