Development of Intestinal Injury and Restoration of Weaned Piglets under Chronic Immune Stress

Abstract

This study aimed to investigate the effects of lipopolysaccharide (LPS)-induced chronic immune stress on intestinal morphology and function, immune system, oxidative status, and mitochondrial function in piglets. Fifty healthy Duroc × Landrace × Yorkshire piglets (21 ± 2 days old, barrow, 6.98 ± 0.14 kg body weight) were selected and randomly allotted to five groups, which were slaughtered at 0 (0 group), 1, 5, 9, and 15 d of LPS injection. The results showed that compared with the piglets without LPS injection, LPS injection significantly impaired the intestinal morphology and permeability at 1, 5, and 9 d, as manifested by the increased serum lactic acid and decreased ratio of villus height to crypt depth (p < 0.05). Moreover, intestinal inflammation and oxidative and mitochondrial injury were caused at 1 d, as manifested by upregulated IL-6 mRNA expression, increased malondialdehyde content, and impaired mitochondrial morphology (p < 0.05). However, these parameters were restored to levels identical to 0 group at 9~15 d, accompanied by significantly increased antioxidant capacity, enhanced protein expression of CD3+ and CD68+, and upregulated mRNA abundance of genes related to mitochondrial biogenesis and functions (p < 0.05). Collectively, these results suggest that the intestinal injury of piglets caused by chronic immune stress could be self-repaired.

Regulation of the growth performance and the gastrointestinal microbiota community by the addition of defective pear fermentation to feed of small-tailed Han sheep

“…As CD increases, villi shrink, reducing digestion. V/C ratio is an indicator of small intestine function (Yu et al, 2022 ).…”

Development and Recovery of Liver Injury in Piglets by Incremental Injection of LPS

“…Piglets were slaughtered on days 0 (0 group, without LPS injection), 1 (1 group), 5 (5 group), 9 (9 group), and 15 (15 group) of LPS injection, respectively. From day 1 of the trial, piglets were injected intraperitoneally with LPS (E. coli serotype 055: B5; Sigma Chemical, St Louis, MO, USA), the injection dose was the same as what we previously reported [ 5 ]. The same amount of 0.90% sterile saline was injected into piglets in the 0 group, which were slaughtered 1 day before the trial.…”

“…During the experimental period of 15 days, the piglets were kept in 1.80 × 1.10 m cages separately (their temperatures remained constant at 25–27 °C) and were allowed ad libitum access to food and water. All diets were formulated to meet the nutrient requirements and physiological needs of weaned piglets, and the ingredients and nutritional values are given in our previous studies [ 5 ].…”

“…The pruned treated liver tissue block was fixed using 2.5% glutaraldehyde and then used to detect the mitochondrial ultrastructure by using the transmission electron microscopy, as previously reported [ 5 ].…”

“…In the early period after weaning, this stress occurs frequently and impairs pig growth and health, ultimately causing immeasurable economic losses to the livestock industry [ 3 , 4 ]. A current area of interest in the field is how intestinal injury occurs and which nutrients are regulatory [ 5 , 6 , 7 ]. Apart from the intestine, another major area of emerging interest is the impact of immune stress on the liver, since it is the final barrier that protects the body from the effects of exogenous toxic substances [ 8 ].…”