Lying, Feeding and Activity Preference of Weaned Piglets for LED-Illuminated vs. Dark Pen Compartments

Little is known on the effect of light on pig behaviour. The choice behaviour of weaned piglets kept under two different light-emitting diode (LED) illuminance levels was investigated: 32 piglets (in two batches) were housed in a preference test room composed of two identical double pen units. One side of the pen unit was permanently illuminated with 600 lux, while the other was darkened to almost 0 lux (~0 lx); by using a passageway, piglets could move between the two sides. The “lying”, “eating” and “activity” behaviours were evaluated during three days in the first, third and fifth experimental week based on video recordings and a 5-min time sampling method. At first, piglets preferred to stay in the 600 lux illuminated compartments. Then, this preference decreased for the “eating” and “activity” behaviours and reversed for the “lying” behaviour, with the darkened compartments being preferred. The results also show that pen soiling was higher under 600 lux, but feed consumption was not affected by the illuminance. Since pigs choose between the two illuminance levels to perform specific behaviours, illuminance could be used to divide the pens into functional areas and, thus, help in meeting pigs’ behavioural needs.

Resveratrol Alleviates Oxidative Stress Induced by Oxidized Soybean Oils and Improves Gut Function via Changing Gut Microbiota in Weaned Piglets

Background: The objective of this study was to investigate the effects of dietary resveratrol supplementation on growth performance, redox status, inflammatory state, and intestinal function of weaned piglets fed oxidized soybean oils.Methods: A total of twenty-eight castrated weaned male piglets with a similar body weight of 10.19 ±1 kg were randomly assigned to 4 dietary treatments for 28 days feeding trial with 7 replications per treatment and 1 piglet per replicate. Treatments were arranged as a 2×2 factorial with oil type [fresh soybean oils (FSOs) vs. oxidized soybean oils (OSOs)] and dietary resveratrol (RES) (0 vs. 300 mg/kg).Result: Inclusion of OSOs decreased the villus/crypt ratio (VCR), while the villus height (VH) and VCR in the jejunum of weaned piglets was increased by dietary RES (P< 0.05). The activities of lipase, chymotrypsin, and lactase were decreased by OSOs, however dietary RES supplementation increased the activities of lipase, chymotrypsin, lactase, and α-amylase in the jejunum of weaned piglets (P< 0.05). Dietary RES increased the apparent digestibility of crude fat (EE). Dietary RES supplementation in the diets supplemented with OSOs decreased the level of interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) in the plasma of weaned piglets, but failed to influence the IL-1β, IL-6, IL-8, and TNF-α level when diets supplemented with FSOs. Dietary RES alleviated the decrease of total-superoxide dismutase activity in the plasma of weaned piglets fed OSOs (P< 0.05). Dietary supplemented with OSOs and RES decreased the level of H2O2 in the plasma of weaned piglets (P< 0.05). RES alleviates the intestinal barrier damage fed OSOs in weaned piglets by increasing the mRNA expression of ZO-1 and Occludin. It is noteworthy that inclusion of OSOs in diets increased the abundance of Actinobacteria, and decreased the abundance of Tenercutes (P< 0.05). RES increased the abundance of Firmicutes, and decreased the abundance of Bacteroidetes (P< 0.05). At the genus level, RES decreased the abundance of Prevotella-1, Prevotellaceae UCG003, and Clostridium_sensu_stricto_6 in the colon. OSOs decreased the level of acetic acid, and dietary RES increased the level of acetic acid and butyric acid in the colon of weaned piglets.Conclusions: Dietary RES supplementation improved the villus-crypt structure, digestive enzyme activities and alleviated OSOs induced digestive absorption disorder. In addition, RES may alleviate OSOs immune status and energy metabolism of weaned piglets by affecting gut microbiota and its metabolite SCFAs. Notably, this positive effect of RES on OSOs may be related to decrease in the abundance of Prevotella_1 and Prevotellaceae_UCG-003.

Dietary l-glutamic acid N,N-diacetic acid improves short-term maintenance of zinc homoeostasis in a model of subclinical zinc deficiency in weaned piglets

This study compared the Zn response in selected tissues of weaned piglets fed L-glutamic acid, N,N-diacetic acid (GLDA), while challenged with short-term subclinical Zn deficiency (SZD). During a total experimental period of eight days, 96 piglets were fed restrictively (450 g/d) a high phytate (9 g/kg) diet containing added Zn at 0, 5, 10, 15, 20, 25, 45 and 75 mg/kg with and without 200 mg/kg of GLDA. No animals showed signs of clinical Zn deficiency and no phenotypical differences were observed. Broken line analysis of Zn status parameters such as liver Zn and apparently absorbed Zn indicated that the gross Zn requirement threshold was around 55 mg/kg diet. Supplementation of Zn above this threshold led to a saturation of the response in apparently absorbed Zn and linear increase in liver Zn. Bone and serum Zn responded to the dose in a linear fashion, likely due to the time-frame of Zn homoeostatic adaptation. Inclusion of GLDA into the diets yielded a higher intercept for bone Zn (P < 0·05). Liver Zn accumulation and MT1A gene expression was higher for piglets receiving GLDA (P < 0·05), indicating higher Zn influx. This study indicates that a strong chelator such as GLDA mitigates negative effects of phytate in plant-based diets, by sustaining Zn solubility, thereby improving nutritional Zn availability.

Influence of the Zinc and Fibre Addition in the Diet on Biomechanical Bone Properties in Weaned Piglets

The effects of the zinc and fibre source in piglets’ diet on the bone mineral content, density, and strength parameters of the femur were investigated using 24 piglets fed a diet supplemented with either lignocellulose (LC) or potato fibre (PF). Half of each group of piglets consumed a diet with ZnSO4 monohydrate or with zinc glycinate (ZnGly). The diets contained similar amounts of lysine, energy, and fibre. Bone mineral content and density were over 9% higher in pigs receiving diets with ZnGly than in animals fed diets with ZnSO4. Moreover, ZnGly strongly improved maximum and elastic strength (by 25.7 and 20.0%, respectively, p < 0.0001) and bone stiffness (by 29.4%, p < 0.0001). Only the mass of the femur was affected by the type of fibre in the diet, as the femurs of piglets fed diets with LC were over 7% (p < 0.0001) heavier than in piglets fed diets with PF. The intake of digestible zinc and the zinc content in the blood serum were positively correlated with the measured bone parameters and, depending on the parameter, “r” ranged from 0.749 to 0.866 and from 0.400 to 0.479, respectively. It can be concluded that bone parameters are affected more strongly by the organic than inorganic source of zinc.

Impacts of Age, Genotype and Feeding Low-Protein Diets on the N-Balance Parameters of Fattening Pigs

The effects of feeding low-protein (LP) diets and the age and genotype of fattening pigs were evaluated in an N-balance trial. Sixty weaned piglets of two genotypes were allotted to three different diets. Besides the control diets for the crossbred Topigs 20 × DanBred Duroc (TD) and Hungarian Large White (HLW) pigs, two LP diets were fed containing 1.5 (T1.5) and 3% (T3) less dietary protein than the control. The LP diets were supplemented with crystalline lysine, threonine, tryptophan, and methionine to equalize their digestible amino acid contents. Starter diets were fed between 20–30, grower I between 30–40, grower II between 40–80 and finisher between 80–110 kg live weights. Pigs were kept in floor pens, with 10 animals per pen. In all phases, six pigs with similar live weight were placed into individual balance cages and in the frame of a seven-day long balance trial, the daily N-intake, fecal and urinary N-excretion were measured. From the data N-digestibility, the total ammoniacal nitrogen (TAN) and N-retention were calculated. All the investigated main factors, the genotype and age of pigs and the protein content of the diets had significant effects on the N-balance of fattening pigs. The determinacy of the factors depended on the investigated parameter. Fecal N-excretion and N-digestibility were steadier compared with the urinary N-exertion and TAN percentage. N-digestibility increased and the urinary N-excretion decreased when LP diets were fed. The urinary N-decreasing effect of LP diets was not linear. Compared with the control (19.6 gN/day), T1.5 treatment resulted in 14.5, treatment T3 in 12.4 g daily urinary N-excretion. The TAN and the N-retention of HLW pigs were more favorable than those of TD pigs. Based on our results, it can be concluded that the accuracy of the nitrogen and TAN excretion values of pigs, used in the calculation of the national NH3 inventories, could be improved if the genotype, the more detailed age categories and the different protein levels of feeds are considered.

The Effects of Different Levels of Citric Acid on Growth Performance, Nutrient Digestibility and Gastrointestinal pH of Weaned Piglets

Background: This study was conducted to evaluate the effects of different levels of citric acid (CA) on the growth performance, nutrient digestibility and gastrointestinal pH of weaned piglets. Methods: A total of 120 weaned piglets with an initial BW of 7.15±0.01 kg, were randomly divided into four groups including control treatment each with three replicates of 10 piglets each. Each group was supplemented with 0.5% (control group), 1%, 1.5% and 2% CA in the basal diet, respectively. Result: The results showed that the average daily feed intake (ADFI) and average daily gain (ADG) of added 1% CA group were significantly higher than that of 0.5% group (P less than 0.05). Dietary CA significantly improved the utilization rates of crude protein, calcium and phosphorus (P less than 0.05), while there was no significant difference between adding 1% and 1.5% CA (P greater than 0.05). Compared with the control group, adding CA effectively reduced the pH of the stomach, duodenum jejunum and ileum contents and adding 2% CA were significantly lower than those in other groups (P less than 0.05). Therefore, the addition of 1.0% CA in the diets of weaned piglets is suitable.

Sophorolipid protects against early-weaning syndrome by improving the gut microenvironment in early-weaned piglets

Background In animals, weaning stress is the first and most critical stress. Weaning can negatively affect the growth performance of animals physically, psychologically, and pathologically. Our previous studies on the HT-29 cell line and early-weaned rats demonstrated that adequate sophorolipid (SPL) supplementation in feed could enhance the mucin-producing and wound healing capacities of the gut defense system by modulating gut microbiota. Methods We conducted an experiment with one hundred forty 21-day-old early weaned piglets (L x Y x D). They were allocated into 4 treatment and 7 replications (4 pigs per pen) according to their initial body weight. Body weight and feed intake were measured biweekly during experimental period. After 6 weeks, 28 pigs were randomly selected and sacrificed to collect plasma, jejunum, and cecal content samples. Results Dietary SPL supplementation at 5 and 10 mg/kg quadratically increased the average daily gain during the experimental period in the treatment groups when compared with the control group. The albumin levels of piglets fed with the SPL supplemented diet were downregulated to the normal range. Moreover, in feed, SPL supplementation at 5 and 10 mg/kg improved jejunal histological indices and gene expression levels related to mucin secretion and local inflammation markers. Consistent with these results, adequate SPL supplementation (5 and 10 mg/kg) increased the population of Prevotella, a beneficial bacterium, and its short-chain fatty acid production in the ceca of piglets. Conclusions The occurrence of diarrhea after weaning in piglets could be reduced by feeding a 10 ppm of SPL supplemented diet which improves the gut defense system by improving the microbial population and enhancing mucin layer integrity.

Effect of Resin Acid and Zinc Oxide on Immune Status of Weaned Piglets Challenged With E. coli Lipopolysaccharide

With the ban of zinc oxide (ZnO) at high dosages in piglet diets in Europe by 2022, alternative nutritional solutions are being tested to support piglet immune defence during their weaning, the most critical and stressful moment of pig production. The present study evaluated the effect of zinc oxide (ZnO; 2,500 mg/kg diet) and resin acid concentrate (RAC; 200 mg/kg diet) on the immune defence of weaned piglets challenged with lipopolysaccharide (LPS). Piglets were challenged at days 7 and 21 post-weaning, and blood was sampled 1.5 and 3.0 h after each challenge to determine serum levels of pro- and anti-inflammatory cytokines. The levels of serum tumour necrosis factor alpha (TNF-α) and interleukin 8 (IL-8) increased at days 7 and 21, and those of IL-6 at day 21 when challenged piglets were fed a diet supplemented with ZnO. In challenged piglets fed with RAC, the serum levels of IL-1β, IL-6, IL-8, IL-10 and TNF-α were increased at days 7 and 21, except for that of IL-1β, which was not affected at day 21. The increased levels of these cytokines indicate the successful immune-modulatory effect of ZnO and RAC, which appears as a candidate to replace ZnO in weaned piglets' diets.