Intrauterine growth retardation (IUGR) usually refers to the retarded growth and development of the fetus or its inner organs during the perinatal period due to various factors, which not only reduces the birth quality and survival rate of piglets, but also negatively affected their growth and development after birth (Longo et al., 2014). The incidence of IUGR in pigs is as high as 20%, which causes a huge loss to the pig production (Wu et al., 2004).
Li et al. (2015) and He et al. (2016) conducted several studies regarding the dietary tributyrinintervention on the IUGR piglets. Three treatments were included in the studies, including the normal group (NBW group, normal piglets + basic artificial milk) , the IUGR group (IUGR piglets + basic artificial milk), and the tributyrin-fed group (IT group IUGR piglets + basic artificial milk + 0.1% tributyrin). The results are as followed:
Improves the pancreas and liver development
研究發現，IUGR 組乳豬的胰腺和肝臟的重量顯著低于正常組；對IUGR仔豬采用三丁酸甘油酯（TB）營養干預后，胰腺重量較IUGR組提高了31.03% (P<0.05)，肝臟重量較IUGR組提高了52.32% (P<0.05)，與正常組相比均無顯著差異。IUGR組仔豬的肝臟組織中央靜脈和門管區充血較嚴重，采用三丁酸甘油酯（TB）營養干預后，則無上述變化。
Their results indicated that the weights of pancreas and liver in the IUGR pigs were obviously lower than that in the normal ones (P<0.05), while dietary tributyrin intervention on the IUGR pigs increased the weights of these organs by 31.03% and 52.32% when compared with those in the IUGR pigs consuming normal feed, respectively. The central vein and portal area of liver in the IUGR pigs were seriously congested, while no such pathologic changes were observed in response to dietary tributyrin intervention.
Improves the intestinal villi morphology
Ameliorates the liver congestion
Improves the pancreatic enzyme activity
The activity of trypsin, pancreatic lipase and amylase in the IUGR piglets were obviously lower than those in the normal pigs (P < 0.05), while activity of these three enzyme in the IUGR pigs with dietary tributyrin intervention were increased by 36.92%, 52.30% and 141.37%, respectively.
Reduces the inflammation response
IUGR仔豬的肝臟中腫瘤壞死因子（TNF-α）與白細胞介素4（IL-4）的水平高于正常組 （P < 0.05），對IUGR仔豬采用三丁酸甘油酯營養干預后，肝臟中TNF-α和IL-4的含量分別降低了35.20%和20.52%。
The liver contents of tumor necrosis factor (TNF-α) and interleukin 4 (IL-4) were significantly higher in the IUGR piglets than those in the normal ones, while these in the IUGR pigs with dietary tributyrin intervention were reduced by 35.20% and 20.52%, respectively.
Improves the antioxidant capacity
SOD和GSH是體內重要的抗氧化劑和自由基清除劑，GSH-Px是機體一種重要的過氧化物分解酶，MDA是體內脂質過氧化產物之一。對IUGR仔豬采用三丁酸甘油酯營養干預后， 體內SOD、GSH和GSH-Px的活性明顯提高（P < 0.05），MDA含量顯著降低；相關指標均優于正常的仔豬。
The SOD and GSH are important antioxidants and free radical scavengers of the body, while GSH-Px is an important organic peroxide decomposition enzyme, and MDA is one the end products of lipid peroxidation. Dietary tributyrin intervention increased the activities of SOD, GSH and GSH-Px, and reduced the MDA content in the IUGR piglets, respectively.
Ameliorates the mitochondria function of the liver
Mitochondria is the part where nutrients are oxidized and metabolized to produce ATP, and it is the main place where oxygen free radicals are produced as well. Mitochondria content is extremely high in the liver tissues. SDH is the only enzyme embedded in the inner membrane of mitochondrial in the tricarboxylic acid cycle. MDH is an important oxidoretase, and Mn-SOD mainly exists in the mitochondrial matrix. As an antioxidant, Mn-SOD plays an important role for diseases prevention inside the body. The results showed that dietary tributyrin intervention increased the activity of SDH, MDH and Mn-SOD in liver of the IUGR piglets (P < 0.05).