Da Motta Stephane Alverina Briguente, Furlani Nathana Rudio, Lourenço Antonio Carlos, Junior Sergio Xavier Silva, Rezende Juliana Cristina Ramos, Hannas Melissa Izabel
Department of Animal Science, Federal University of Viçosa, Viçosa 36570-900, Minas Gerais, Brazil.
CJ do Brazil, Piracicaba 13432-700, São Paulo, Brazil.
Animals (Basel). 2025 Apr 23;15(9):1194. doi: 10.3390/ani15091194.
This study aimed to evaluate the effects of the standardized ileal digestible tryptophan-to-lysine (SID Trp-Lys) ratio through the supplementation of different levels of L-tryptophan on pig performance and immune response following an LPS challenge. A total of 120 entire male pigs, with an average body weight of 16.5 ± 0.50 kg, were allocated in a randomized block design with four treatments, ten replicates per treatment, and three animals per experimental unit. The experimental treatments consisted of SID Trp-Lys ratios of 16%, 18%, 21%, and 24%, achieved through L-tryptophan supplementation. The evaluated performance parameters included the final body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR). Blood samples were collected on day 21 to determine serum serotonin levels, and on day 26, pigs were inoculated with LPS to induce an immune challenge, followed by blood sampling to assess cytokine responses. The results showed that pigs fed the 16% SID Trp-Lys ratio exhibited a lower FBW ( < 0.05). The SID Trp-Lys ratios influenced performance parameters, with quadratic responses ( < 0.05) observed for the FBW and FCR, where the highest FBW and lowest FCR were recorded at 22.05% and 21% SID Trp-Lys, respectively. A linear increase ( < 0.05) was observed for ADG, with a trend for a linear increase ( = 0.056) in ADFI. No effects ( > 0.10) of the SID Trp-Lys ratios were detected on serum serotonin levels. An increase in cytokine levels (GM-CSF, IFN-γ, IL-1α, IL-1β, IL-1ra, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, and TNF-α) was observed in pigs challenged with LPS ( < 0.10) compared to non-challenged animals. An interaction effect ( < 0.10) was detected for IL-2 and IL-18. SID Trp-Lys ratios between 21% and 24% optimize growth performance in pigs from 16 to 33 kg and modulate the immune response under LPS-induced challenge conditions.
本研究旨在通过补充不同水平的L-色氨酸来评估标准化回肠可消化色氨酸与赖氨酸（SID Trp-Lys）比值对猪在脂多糖（LPS）攻毒后的生长性能和免疫反应的影响。总共120头去势公猪，平均体重为16.5±0.50千克，采用随机区组设计，分为四种处理，每个处理十个重复，每个实验单元三头猪。实验处理包括通过补充L-色氨酸实现的16%、18%、21%和24%的SID Trp-Lys比值。评估的生长性能参数包括末体重（BW）、平均日增重（ADG）、平均日采食量（ADFI）和饲料转化率（FCR）。在第21天采集血样以测定血清5-羟色胺水平，在第26天，给猪接种LPS以诱导免疫攻毒，随后采集血样以评估细胞因子反应。结果表明，饲喂16% SID Trp-Lys比值的猪末体重较低（P<0.05）。SID Trp-Lys比值影响生长性能参数，末体重和饲料转化率呈二次反应（P<0.05），其中最高末体重和最低饲料转化率分别出现在22.05%和21%的SID Trp-Lys时。平均日增重呈线性增加（P<0.05），平均日采食量有线性增加趋势（P = 0.056）。未检测到SID Trp-Lys比值对血清5-羟色胺水平有影响（P>0.10）。与未攻毒动物相比，用LPS攻毒的猪细胞因子水平（GM-CSF、IFN-γ、IL-1α、IL-1β、IL-1ra、IL-4、IL-6、IL-8、IL-10、IL-12、IL-18和TNF-α）升高（P<0.10）。检测到IL-2和IL-18有交互作用（P<0.10）。21%至24%的SID Trp-Lys比值可优化16至33千克猪的生长性能，并在LPS诱导的攻毒条件下调节免疫反应。
