Department of Animal and Poultry Nutrition, Animal Science Faculty, Gorgan University of Agricultural Science and Natural Resources, Gorgan, Iran.
J Anim Physiol Anim Nutr (Berl). 2024 Sep;108(5):1231-1242. doi: 10.1111/jpn.13971. Epub 2024 Apr 20.
Global warming threatens livestock production, especially in hot climates. This study evaluated the dose-dependent impacts of dietary curcumin nano-micelles (CNM) on rumen fermentation, nitrogen metabolism, and nutrient digestibility in heat-stressed fattening lambs. Thirty-two crossbred male lambs [ˆIle-de-France × (Dalagh × Romanov)] were utilized within the current study. The initial weight of lambs was documented as averaged by 31.2 ± 1.55 kg, while they were in their 4th to 5th months of age. Animals were fed increasing doses of dietary CNM (0, 20, 40, and 80 mg/day) over 97 days, under severe heat stress conditions with average temperature-humidity index (THI) of 24.5. Quadratic improvements (p < 0.01) occurred in weight gain, average daily gain (ADG), and feed conversion ratio (FCR) by 28.7%, 27.4%, and 23.9%, respectively, in the T40 group compared to the control. Additionally, T40 increased fiber digestion by 2.8% (p < 0.05). Furthermore, T40 quadratically improved parameters of rumen fermentation, including concentrations of NH3-N (p < 0.05), total volatile fatty acids (TVFA; p < 0.01), acetate (p < 0.05), and iso-valerate (p < 0.05), by 13.9%, 12.5%, 15.0%, and 43.5%, respectively, compared to the control. Quadratic increases were also observed in nitrogen balance (p < 0.05) and microbial protein synthesis (p < 0.01) by 19.8% and 37.6%, respectively, in the T40 group. Quadratic models estimated optimal CNM levels between 41.5 and 48.6 mg/day for multiple parameters. These findings indicate CNM at dose level of 40 mg/day could benefit heat-stressed lambs through enhanced rumen function and microbiota. Further research should refine ideal dosing for various species and production phases as higher levels adversely impacted fiber digestibility. Overall, CNM shows promise as a sustainable nutritional intervention for livestock production facing global warming.
全球变暖威胁着畜牧业生产，尤其是在炎热的气候条件下。本研究评估了日粮姜黄素纳米胶束（CNM）对热应激育肥羔羊瘤胃发酵、氮代谢和养分消化率的剂量依赖性影响。本研究采用了 32 只杂交雄性羔羊（ˆIle-de-France × （Dalagh × Romanov））。羔羊的初始体重记录为 31.2 ± 1.55 kg，处于 4-5 月龄。在平均温度-湿度指数（THI）为 24.5 的严重热应激条件下，动物在 97 天内摄入不同剂量的日粮 CNM（0、20、40 和 80 mg/天）。T40 组的体重增加、平均日增重（ADG）和饲料转化率（FCR）分别提高了 28.7%、27.4%和 23.9%（p < 0.01）。此外，T40 组纤维消化率提高了 2.8%（p < 0.05）。此外，T40 组瘤胃发酵参数呈二次改善，包括氨氮浓度（p < 0.05）、总挥发性脂肪酸（TVFA；p < 0.01）、乙酸（p < 0.05）和异戊酸（p < 0.05）分别提高了 13.9%、12.5%、15.0%和 43.5%。T40 组的氮平衡（p < 0.05）和微生物蛋白合成（p < 0.01）也呈二次增加，分别增加了 19.8%和 37.6%。二次模型估计，对于多个参数，CNM 的最佳水平在 41.5 至 48.6 mg/天之间。这些发现表明，日粮中添加 40 mg/天的 CNM 可以通过增强瘤胃功能和微生物群来使热应激羔羊受益。进一步的研究应该为不同的物种和生产阶段细化理想的剂量，因为更高的剂量会对纤维消化率产生不利影响。总的来说，CNM 作为一种可持续的营养干预措施，有望应用于应对全球变暖的畜牧业生产。
