【原创】热应激对生长猪血清中游离氨基酸及其部分代谢产物浓度的影响

畜牧编辑

　　热应激对生长猪血清中游离氨基酸及其代谢产物浓度的影响

　　A. Morales, S.E. M. Cota, N. O. Ibarra, N. Arce, J. K. Htoo和M. Cervantes

　　热应激（HS）可能会影响猪小肠上皮，导致消化吸收能力受损。血清游离氨基酸浓度可以作为其可利用率的指示剂。本研究使用12头杂交猪（长×汉普夏×杜洛克，初始重29.0 ± 2.8 kg）分为2组，用于测定热应激下猪血清游离氨基酸浓度和部分氨基酸代谢产物。处理组分别为无环境温度控制的自然热应激环境（23.6 to 37.6°C, HS），适温环境 (24 ± 2°C)组猪只采食量限制与热应激组相同。日粮为小麦-豆粕型日粮。在吸收阶段（采食后2.5h）和平稳阶段（采食后10.0 h）收集血液样品。与适温组猪相比，热应激组猪在吸收阶段血清中精氨酸、亮氨酸、赖氨酸、苯丙氨酸、苏氨酸和色氨酸明显偏低(P < 0.05)，组氨酸、缬氨酸、丙氨酸、脯氨酸、丝氨酸和酪氨酸有降低的趋势(P < 0.10) 。在平稳阶段，热应激组猪血清精氨酸、组氨酸、蛋氨酸、天门冬酰胺、谷氨酰胺和酪氨酸明显偏高(P < 0.05)，但丙氨酸(P <0.01)和脯氨酸明显偏低(P < 0.10)。吸收阶段，热应激组猪血清中肌肽、鸟氨酸（Orn）和牛磺酸明显偏低(P < 0.05)，瓜氨酸（Cit）、胱硫醚和尿素浓度有降低的趋势(P <0.10)。平稳阶段，热应激组猪血清3-甲基-组氨酸、同型半胱氨酸、羟赖氨酸和羟脯氨酸明显偏高，瓜氨酸有偏高的趋势(P = 0.10)，而肌肽和肌氨酸浓度明显偏低(P <0.05)。结果表明热应激明显影响猪血清氨基酸浓度。总之，热应激会损伤猪消化吸收能力，部分氨基酸的代谢被调整以抵消热应激带来的负面影响。

　　Effect of heat stress on the serum concentrations of free amino acids and some of their metabolites in growing pigs

　　A. Morales, S. E. M. Cota, N. O. Ibarra, N. Arce, J. K. Htoo and M. Cervantes

　　Exposure to heat stress (HS) may affect the intestinal epithelia of pigs, resulting in impaired digestive and absorptive capacity. The serum concentration (SC) offree AA in pigs can be used as indicators of their availability. This study was conducted with 12 crossbred (Landrace × Hampshire × Duroc) pigs (29.0 ± 2.8 kg initial BW) distributed into 2 groups to analyze the SC of free AA and some AA metabolites in pigs exposed to HS conditions. The treatments were pigs housed under natural HS conditions in a room with no ambient temperature control (23.6 to 37.6°C, HS) and pigs housed at thermoneutral conditions (24 ± 2°C), feed restricted to a level similar to that of their HS counterparts. All pigs received a wheat–soybean meal diet. Blood samples were collected at both the absorptive (2.5 h after a meal) and postabsorptive (10.0 h after a meal) phase. At the absorptive phase, the SC of free Arg, Leu, Lys, Phe, Thr, and Trp were lower (P < 0.05) and the SC of His, Val, Ala, Pro, Ser, and Tyr tended to be lower (P < 0.10) in HS pigs. At the post absorptive phase, the SC of free Arg, His, Met, Asn, Gln, and Tyr were higher (P <0.05) but the SC of Ala was lower (P < 0.01) and the SC of Pro tended to be lower (P < 0.10) in HS pigs. The absorptive SC of carnosine, ornithine (Orn), and Tau were lower (P < 0.05) and of citrulline (Cit), cystathionine, and urea tended to be lower (P <0.10) in HS pigs. The postabsorptive SC of 3-methyl-His, homo-Cys, OH-Lys, and OH-Pro increased (P = 0.05) and of Cit tended to increase (P =0.10) but that of carnosine and sarcosine (P < 0.05) decreased in HS pigs.The results of this study show a marked and differential effect of HS on the SC of AA. These data indicate that HS negatively affects the digestive and absorptive capacity of pigs and that the metabolism of some AA is modified in pigs to counteract the negative effects of the HS。

翻译：杜环利
[url=]转自：猪营养国际论坛CSIS[/url]