Wang Xintao, Chen Daiwen, Pu Junning, Tian Gang, He Jun, Zheng Ping, Yu Jie, Yu Bing
Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China.
Key Laboratory of Animal Disease-Resistance Nutrition, China Ministry of Education, China Ministry of Agriculture and Rural Affairs, Key Laboratory of Sichuan Province, Chengdu 611130, China.
Animals (Basel). 2025 Sep 11;15(18):2663. doi: 10.3390/ani15182663.
In China, the application of low-protein, low-soybean meal diversified feeding strategies exhibits significant importance for reducing the dependence on soybean meal imports, lowering livestock and poultry feed costs, and decreasing nitrogen emissions from animal husbandry. Dietary protein content reduction modulates energy metabolism, while nonconventional feed ingredients alter energy efficiency. This study aimed to evaluate the effects of varying net energy (NE) levels on growth performance, nutrient digestibility, carcass characteristics, meat quality, and colonic microbiota in finishing pigs fed low-protein diversified diets. A total of 108 Duroc × Landrace × Yorkshire pigs (initial body weight: 79.8 ± 6.5 kg) were randomly assigned to six treatment groups: one control group fed a conventional corn-soybean meal diet with normal crude protein (CP) content and five groups fed low-protein diversified diets with different NE levels. The experiment was conducted over 49 days. During the 80-100 kg phase, pigs receiving the low-protein diversified diet exhibited a 9.12% improvement in feed-to-gain ratio (F/G) compared to the control group ( < 0.05). Additionally, dietary dry matter (DM) and ether extract (EE) digestibility significantly increased ( < 0.05). As NE levels increased under low-protein conditions, F/G decreased linearly ( < 0.05), while DM, gross energy (GE), EE, and CP digestibility showed significant linear and quadratic increase ( < 0.05). In the 100-130 kg phase (22-49 d), pigs in the low-protein diversified diet group demonstrated a 5.10% increase in average daily feed intake (ADFI) and an 8.60% increase in average daily gain (ADG), compared to the control group with normal CP content and the same NE level. Furthermore, dietary GE, EE, and CP digestibility improved significantly ( < 0.05). Under low-protein diversified diet conditions, as NE levels increased, F/G decreased significantly, ADFI decreased, and ADG increased to varying degrees. Similarly, DM, GE, EE, and CP digestibility showed significant increases. Carcass weight tended to increase linearly, while the slaughter rate initially increased before decreasing. Notably, low-protein diversified diets were associated with greater microbial community diversity in colonic digesta. The findings indicated that the optimal dietary NE for a low-protein diversified diet during the 80-100 kg phase was 9.84-10.21 MJ/kg, and 9.49-10.02 MJ/kg during the 100-130 kg phase. These results highlighted the importance of optimizing dietary NE levels in low-protein feeding strategies to enhance growth performance, nutrient utilization, and gut microbiota composition in finishing pigs.
在中国，应用低蛋白、低豆粕的多样化饲喂策略对于减少对豆粕进口的依赖、降低畜禽饲料成本以及减少畜牧业氮排放具有重要意义。日粮蛋白质含量降低会调节能量代谢，而非传统饲料原料会改变能量效率。本研究旨在评估不同净能（NE）水平对饲喂低蛋白多样化日粮的育肥猪生长性能、养分消化率、胴体特性、肉质和结肠微生物群的影响。总共108头杜洛克×长白×大白猪（初始体重：79.8±6.5千克）被随机分配到六个处理组：一个对照组饲喂粗蛋白（CP）含量正常的常规玉米 - 豆粕日粮，五个组饲喂不同NE水平的低蛋白多样化日粮。试验持续49天。在80 - 100千克阶段，与对照组相比，接受低蛋白多样化日粮的猪的料重比（F/G）提高了9.12%（P<0.05）。此外，日粮干物质（DM）和乙醚提取物（EE）消化率显著提高（P<0.05）。在低蛋白条件下，随着NE水平的增加，F/G呈线性下降（P<0.05），而DM、总能（GE）、EE和CP消化率呈显著的线性和二次增加（P<0.05）。在100 - 130千克阶段（22 - 49天），与CP含量正常且NE水平相同的对照组相比，低蛋白多样化日粮组的猪平均日采食量（ADFI）增加了5.10%，平均日增重（ADG）增加了8.60%。此外，日粮GE、EE和CP消化率显著提高（P<0.05）。在低蛋白多样化日粮条件下，随着NE水平的增加，F/G显著下降，ADFI下降，ADG有不同程度的增加。同样，DM、GE、EE和CP消化率显著提高。胴体重呈线性增加趋势，屠宰率先增加后下降。值得注意的是，低蛋白多样化日粮与结肠内容物中更大的微生物群落多样性相关。研究结果表明，80 - 100千克阶段低蛋白多样化日粮的最佳日粮NE为9.84 - 10.21兆焦/千克，100 - 130千克阶段为9.49 - 10.02兆焦/千克。这些结果突出了在低蛋白饲喂策略中优化日粮NE水平对于提高育肥猪生长性能、养分利用和肠道微生物群组成的重要性。
