Impacts of weaning weights and mycotoxin challenges on jejunal mucosa-associated microbiota, intestinal and systemic health, and growth performance of nursery pigs

Effects of Pigs' Weaning Weight on Growth Performance and Blood Immunological, Antioxidant, and Gut Permeability Parameters in Early Nursery Period

This study was conducted to investigate the effect of pigs' weaning weight (WW) on their growth performance and blood immunological, antioxidant, and gut permeability parameters in the early nursery period. At weaning, a total of 48 pigs, weaned at 20.7 ± 0.74 d of age, were allotted to two WW categories-HWW, with a WW over 5.5 kg (average 6.79 ± 0.53 kg), and LWW, with a WW of less than 5.5 kg (average 4.43 ± 0.56 kg)-for a 14 d postweaning period. The WW did not affect the average daily gain (ADG) in d 0-7 postweaning or the plasma malondialdehyde levels over the entire period. HWW pigs had a higher body weight and ADG than LWW pigs (p < 0.05) in the overall period, with greater plasma immunoglobulin G (p < 0.05) and A (p = 0.06, tendency) levels at d 7 postweaning and superoxide dismutase activity at d 14 postweaning (p = 0.05, tendency), with positive correlations with the WW (p < 0.05). HWW pigs had lower plasma diamine oxidase (p < 0.05) and d-lactate (p = 0.06, tendency) levels at d 14 postweaning, with a negative correlation with the WW (p < 0.05). In conclusion, although there was no effect of the WW on growth rate in the first week postweaning and oxidative stress in the early nursery period, HWW pigs exhibited greater growth performance, immunoglobulin levels, and antioxidant capacity but lower gut permeability than LWW pigs in the early nursery period.

Aflatoxin B1: Challenges and Strategies for the Intestinal Microbiota and Intestinal Health of Monogastric Animals

The objective of this review is to investigate the impacts of aflatoxins, particularly aflatoxin B1 (AFB1), on intestinal microbiota, intestinal health, and growth performance in monogastric animals, primarily chickens and pigs, as well as dietary interventions to mitigate these effects. Aflatoxin B1 contamination in feeds disrupts intestinal microbiota, induces immune responses and oxidative damage, increases antioxidant activity, and impairs jejunal cell viability, barrier function, and morphology in the small intestine. These changes compromise nutrient digestion and reduce growth performance in animals. The negative impact of AFB1 on the % change in average daily gain (ΔADG) of chickens and pigs was estimated based on meta-analysis: ΔADG (%)chicken = -0.13 × AFB1 intake per body weight (ng/g·d) and ΔADG (%)pig = -0.74 × AFB1 intake per body weight (µg/kg·d), indicating that increasing AFB1 contamination linearly reduces the growth of animals. To mitigate the harmful impacts of AFB1, various dietary strategies have been effective. Mycotoxin-detoxifying agents include mycotoxin-adsorbing agents, such as clay and yeast cell wall compounds, binding to AFB1 and mycotoxin-biotransforming agents, such as specific strains of Bacillus subtilis and mycotoxin-degrading enzyme, degrading AFB1 into non-toxic metabolites such as aflatoxin D1. Multiple mycotoxin-detoxifying agents are often combined and used together to improve the intestinal health and growth of chickens and pigs fed AFB1-contaminated feeds. In summary, AFB1 negatively impacts intestinal microbiota, induces immune responses and oxidative stress, disrupts intestinal morphology, and impairs nutrient digestion in the small intestine, leading to reduced growth performance. Supplementing multi-component mycotoxin-detoxifying agents in feeds could effectively adsorb and degrade AFB1 co-contaminated with other mycotoxins prior to its absorption in the small intestine, preventing its negative impacts on the intestinal health and growth performance of chickens and pigs.

Effects of β-mannanase supplementation on intestinal health and growth of nursery pigs

Two experiments were conducted using 120 pigs to test the hypothesis that supplementation of β-mannanase could reduce digesta viscosity, enhance nutrient digestion, and improve intestinal health and growth of nursery pigs. In experiment 1, 48 crossbred barrows were randomly allotted to four treatments with increasing levels of β-mannanase at 0, 200, 400, and 600 U/kg in feeds. All pigs were euthanized on day 12 to collect jejunal digesta to measure digesta viscosity and ileal digesta to measure apparent ileal digestibility (AID) of dry matter (DM), gross energy (GE), neutral detergent fiber (NDF), and acid detergent fiber (ADF). In experiment 2, 72 nursery pigs were randomly allotted to three treatments with increasing levels of β-mannanase at 0, 400, and 600 U/kg in feeds. Plasma collected on day 9 was used to measure tumor necrosis factor-α (TNF-α), immunoglobulin G (IgG), malondialdehyde (MDA), and protein carbonyl (PC). All pigs were euthanized on day 10 to collect duodenal and jejunal tissues to evaluate the production of TNF-α, IL-6, and MDA, morphology, crypt cell proliferation, and expression of tight junction proteins in the jejunum. Data were analyzed using the MIXED procedure for polynomial contrasts and the NLMIXED procedure for broken-line analysis of SAS. In experiment 1, β-mannanase supplementation tended to have quadratic effects on digesta viscosity (P = 0.085) and AID of GE (P = 0.093) in the pigs. In experiment 2, jejunal digesta viscosity of the pigs was reduced (P < 0.05) when β-mannanase was supplemented at 360 U/kg of feed. β-Mannanase supplementation linearly reduced (P < 0.05) TNF-α, IgG, MDA, and PC in the duodenum, and TNF-α, IgG, and MDA in the jejunum of the pigs. β-Mannanase supplementation linearly increased (P < 0.05) villus height to crypt depth ratio and crypt cell proliferation in the jejunum. β-Mannanase supplementation tended to linearly improve (P = 0.083) expression of zonula occludens-1 in the jejunum. In conclusion, supplementation of β-mannanase at 360 U/kg reduced the digesta viscosity and up to 600 U/kg positively affected intestinal health and growth of pigs by reducing inflammation and oxidative stress whilst enhancing structure and barrier function in the jejunum.

Improving feed intake and rumen fermentation in lambs using mixed-dimensional attapulgite clay to adsorb naturally occurring mycotoxins

This experiment was conducted to evaluate the effects of including a mixed-dimensional attapulgite clay (MDA) into a naturally moldly diet for Hu lambs. Fifty male Hu lambs with similar initial body weight (28.24 ± 1.80 kg) were randomly allocated into five dietary treatments: a basal diet containing naturally occurring mycotoxins with 0, 0.5, 1.0, and 2.0 kg/t MDA, and basal diet with a commercial mycotoxin adsorbent Solis with montmorillonite as the major component at 1 kg/t. Both MDA and Solis increased average daily gain (ADG) and dry matter intake (DMI; P ≤ 0.004), and there was no difference in growth performance between MDA and Solis (P ≥ 0.26). The final body weight, DMI, and ADG were linearly increased with increasing MDA supplementation (P < 0.01). Lambs treated with both MDA and Solis demonstrated greater apparent digestibility of dry matter (DM), organic matter (OM), and energy compared with the control group (P ≤ 0.03), and there were no differences in nutrient digestibilities between MDA and Solis (P ≥ 0.38). Digestibility of CP was linearly increased with the increasing MDA supplementation (P = 0.01). Neither MDA nor Solis affected rumen total volatile fatty acid (TVFA) concentration (P ≥ 0.39), but decreased the acetate-to-propionate ratio and molar proportion of n-butyrate (P ≤ 0.01), and MDA also increased the concentration of ammonia (P = 0.003). Besides, increasing MDA supplementation linearly reduced the acetate-to-propionate ratio and molar proportion of n-butyrate (P = 0.01), but linearly and quadratically increased the concentration of ammonia (P ≥ 0.003). These results showed that the incorporation of MDA into a naturally moldy diet of Hu lambs yielded comparable results to the Solis product, with higher growth performance and nutrient digestibility but lower acetate-to-propionate ratio observed. In conclusion, including ≥ 1 kg/t of MDA in high mycotoxin risk diets for growing lambs improves feed intake and rumen fermentation.

Maternal Vitamin D and Inulin Supplementation in Oxidized Oil Diet Improves Growth Performance and Hepatic Innate Immunity in Offspring Mice

Dietary oxidized fat contains harmful materials such as hydrogen peroxide and malondialdehyde (MDA). Excessive oxidized fat intake during pregnancy and lactation not only leads to maternal body injury but also damages offspring health. Our previous study demonstrated that vitamin D (VD) had antioxidative capability in sows. This study was conducted to investigate the effect of maternal VD and inulin supplementation in oxidized oil diet on the growth performance and oxidative stress of their offspring. Sixty 5-month-old C57BL/6N female mice were randomly divided into five groups: Control group (basal diet, n = 12), OF group (oxidized-soybean-oil-replaced diet, n = 12), OFV group (oxidized-soybean-oil-replaced diet + 7000 IU/kg VD, n = 12), OFI group (oxidized-soybean-oil-replaced diet + 5% inulin, n = 12) and OFVI group (oxidized-soybean-oil-replaced diet + 7000 IU/kg VD + 5% inulin, n = 12). Mice were fed with the respective diet during pregnancy and lactation. The offspring were then slaughtered on day 21 of age at weaning. Results showed that a maternal oxidized oil diet impaired body weight and liver weight gain of offspring during lactation compared to the control group, while maternal VD, inulin or VD and inulin mixture supplementation reversed this effect. In addition, the activity of T-AOC in the liver of offspring was lower in the OF group than that in the control group, but could be restored by maternal VD and inulin mixture supplementation. Furthermore, the gene expression of both proinflammatory and anti-inflammatory cytokines, such as Il-6, Tnfα and Il-10, in offspring liver were downregulated by a maternal oxidized oil diet compared with the control group, but they were restored by maternal VD or VD and inulin mixture supplementation. The expressions of Vdr and Cyp27a1 were decreased by a maternal oxidized oil diet compared with the control group, while they could be increased by VD or VD and inulin mixture supplementation. Conclusion: maternal oxidized oil diet intake could impair the growth performance by inducing oxidative stress, but this can be relieved by maternal VD and inulin supplementation.