母猪妊娠期不同能量水平对后代公猪生长性能、睾丸发育与免疫的影响

试验旨在研究母猪妊娠期能量水平对后代睾丸发育与免疫的影响及其作用机理。选取30头体重、背膘相近的7~9胎长白×约克夏（LY）经产母猪，按照体重和胎次随机分为2组，每组15个重复，每个重复1头母猪，从妊娠当天分别饲喂正常能量（CON）和低能量饲粮（LE，12.55 MJ/kg），直到分娩，所有母猪哺乳期均饲喂同一饲粮。分娩后，分别从CON和LE组中挑选体重为平均体重±0.05 kg的后代公猪各15头，断奶后所有公猪按阶段饲喂相同饲粮，于仔猪120日龄时结束试验。记录公猪每个月的体重并计算阶段平均日增重和平均日采食量；采集28和120 d的血液进行血清生化指标和免疫相关细胞因子检测，采集28和120 d的睾丸进行睾丸细胞计数和睾丸免疫相关基因检测。结果表明，与对照组相比，LE组0~59 d平均日增重极显著降低（P<0.01），28~89 d平均日采食量和0 d睾丸重显著降低（P<0.05），28 d睾丸指数显著增加（P<0.05）；LE组0和120 d睾丸组织内间质细胞数目、120 d生殖细胞数目、28和120 d支持细胞数目均显著降低（P<0.05）；LE组血清中28 d甘油三酯（TG）和120 d睾酮（T）含量均极显著升高（P<0.01）、雌二醇（E₂）含量极显著降低（P<0.01），TG、T和E₂含量均存在时间和能量的交互作用（P<0.01）；LE组血液中胆固醇（TC）、高密度脂蛋白胆固醇（HDL-C）的含量120 d时极显著降低（P<0.01），低密度脂蛋白胆固醇（LDL-C）、TC、HDL-C三者均无时间和能量的交互作用（P>0.05）。随着公猪日龄增加，血液中白细胞介素-1α（IL-1α）、肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）、免疫球蛋白（IgG）浓度均极显著增加（P<0.01），其中TNF-α和IL-1β有能量和时间的交互作用。与对照组相比，LE组28 d时TNF-α含量显著降低（P<0.05），120 d时IL-1β水平显著升高（P<0.05）。LE组28 d紧密连接蛋白1（ZO1）及0和28 d闭合蛋白（Occludin）基因相对表达量均显著降低（P<0.05），28和120 d时连接黏附分子1（JAM1）基因相对表达量显著增加（P<0.05）。LE组0 d时CCL4基因和28 d时IL-1α基因相对表达量均显著降低（P<0.05），0和120 d时趋化因子2（CCL2）基因及28 d时细胞间黏附分子1（ICAM1）和酪氨酸激酶2（JAK2）基因相对表达量均显著增加（P<0.05）。与对照组相比，28 d时Toll样受体1（TLR1）基因、0 d时肿瘤坏死因子受体超家族成员Ⅰ型（TNFRSF1A）基因相对表达量均显著降低（P<0.05），0 d时B细胞κ轻肽基因增强子核因子抑制因子（NFKBIA）、IL-1β和干扰素（IFNG）基因相对表达量均显著增加（P<0.05）。综上所述，母猪妊娠期摄入12.55 MJ/kg能量水平饲粮可降低后代公猪日增重、平均日采食量和睾丸重；降低后代公猪睾丸内生殖细胞数量及免疫相关细胞因子和睾丸免疫相关基因的表达，从而对后代成年后的免疫能力和繁殖性能产生深远影响。

Effect of Different Energy Levels of Pregnant Sow on the Testicular Development and Immunity of Male Offspring

The experiment was aimed to study the effect of energy level during pregnancy on testicular development and immunity of offspring and its mechanism. 30 Landrace×Yorkshire(LY) sows (7-9 parity) with similar weight and backfat thickness were selected, and randomly divided into 2 groups, each group had 15 repetitions and 1 sow per repetition. From the day of pregnancy, normal energy (CON) and low energy diet (LE, 12.55 MJ/kg) were fed respectively until delivery. All sows were fed the same diet during lactation. After parturition, 15 offspring boars with an average weight ±0.05 kg were selected respectively from CON and LE groups, and fed with the same diet during the experiment. The experiment was ended at 120 day of age. The body weight of boars in each month was recorded, the daily gain and average daily feed intake were calculated. Blood samples were collected at 28 and 120 d for serum biochemical indexes and immune-related cytokines, and testis were collected at 28 and 120 d for testicular cell count and immune-related genes detection. The results showed that compared with control group, the average daily gain from 0 to 59 d in LE group was significantly decreased (P<0.01), the average daily feed intake from 28 to 89 d and the testicular weight on 0 day were significantly decreased (P<0.05), and the testicular index on 28 d was significantly increased (P<0.05). The number of Leydig cells at 0 and 120 d, germ cells at 120 d and Sertoli cells at 28 and 120 d in LE group were significantly decreased (P<0.05). TG content 28 d and T content at 120 d of serum were significantly increased (P<0.01), E2 content was significantly decreased (P<0.01) in LE group. The contents of TG, T and E₂ were influenced by time and energy (P<0.01). The contents of TC and HDL-C in blood of LE group were significantly decreased at 120 d (P<0.01), and there was no interaction between time and energy among LDL-C, TC and HDL-C (P>0.05). The results of immune-related cytokine assay showed that the concentrations of IL-1α, TNF-α, IL-1β and IgG in the blood of boars increased significantly with the increasing of boar age (P<0.01), and TNF-α and IL-1β had the interaction of energy and time. Compared with control group, the content of TNF-α in LE group at 28 d was significantly decreased (P<0.05), and the level of IL-1β in LE group at 120 d was significantly increased (P<0.05). The relative expression level of ZO1 gene at 28 d and Occludin gene at 0 and 28 d in LE group were significantly decreased (P<0.05), and the relative expression level of JAM1 gene at 28 and 120 d was significantly increased (P<0.05). The relative expression level of CCL4 gene at 0 d and IL-1α gene at 28 d was significantly decreased (P<0.05), and the relative expression level of CCL2 gene at 0 and 120 d and ICAM1 and JAK2 genes at 28 d was significantly increased (P<0.05). Compared with control group, the relative expression of TLR1 gene at 28 d and TNFRSF1A gene at 0 d were significantly decreased (P<0.05), while the relative expression levels of NFKBIA, IL-1β and IFNG genes at 0 d were significantly increased (P<0.05). In summary, 12.55 MJ/kg energy intake during pregnancy could reduce the daily gain, average daily feed intake and testicular weight of offspring boars, reduce the number of germ cells in testis of offspring boars and the expression of immune-related cytokines and testicular genes, which had a profound impact on the immune ability and reproductive performance of adult offspring.