The acute phase protein haptoglobin and its relation to oxidative status in piglets undergoing weaning-induced stress

Abstract

Haptoglobin (Hp) prevents the hemoglobin driven generation of hydroxyl radicals and lipid peroxides. Hp can reduce the neutrophil respiratory burst and is an antioxidative molecule in its own right. We aimed to evaluate Hp concentrations, oxidative stress and antioxidative capacity in blood during weaning and to characterise potential relationships between these parameters. Two batches of 10 piglets each (2 trials) weaned at the age of 27–30 days were fed a starter feed mix ad libitum. Blood samples were taken 1 week before weaning and at weekly intervals thereafter. Oxidative stress was monitored via the D-ROM^® system, antioxidative capacity was measured with the TEAC assay and Hp concentrations were measured by ELISA. Neutrophil phagocytic activity and oxidative burst were examined via flow-cytometry. Body weights were recorded weekly. Hp concentrations were increased in both trials post-weaning (P < 0.01); oxidative stress and oxidative burst were elevated in trial I (P < 0.005). In trial I, Hp and ROM values returned to baseline levels at 6 weeks post-weaning. The piglets in trial II showed respiratory symptoms and maintained elevated Hp concentrations. ROM values and Hp were related (r = 0.58; P < 0.01). Hp and body weight gain were inversely related post-weaning.     

Increasing weaning age of piglets from 4 to 7 weeks reduces stress, increases post-weaning feed intake but does not improve intestinal functionality

This study tested the hypothesis that late weaning and the availability of creep feed during the suckling period compared with early weaning, improves feed intake, decreases stress and improves the integrity of the intestinal tract. In this study with 160 piglets of 16 litters, late weaning at 7 weeks of age was compared with early weaning at 4 weeks, with or without creep feeding during the suckling period, on post-weaning feed intake, plasma cortisol (as an indicator of stress) and plasma intestinal fatty acid binding protein (I-FABP; a marker for mild intestinal injury) concentrations, intestinal morphology, intestinal (macro)molecular permeability and intestinal fluid absorption as indicators of small intestinal integrity. Post-weaning feed intake was similar in piglets weaned at 4 weeks and offered creep feed or not, but higher (P < 0.001) in piglets weaned at 7 weeks with a higher (P < 0.05) intake for piglets offered creep feed compared with piglets from whom creep feed was witheld. Plasma cortisol response at the day of weaning was lower in piglets weaned at 7 weeks compared with piglets weaned at 4 weeks, and creep feed did not affect cortisol concentration. Plasma I-FABP concentration was not affected by the age of weaning and creep feeding. Intestinal (macro)molecular permeability was not affected by the age of weaning and creep feeding. Both in uninfected and enterotoxigenic Escherichia coli-infected small intestinal segments net fluid absorption was not affected by the age of weaning or creep feeding. Creep feeding, but not the age of weaning, resulted in higher villi and increased crypt depth. In conclusion, weaning at 7 weeks of age in combination with creep feeding improves post-weaning feed intake and reduces weaning stress but does not improve functional characteristics of the small intestinal mucosa.     

Small intestine growth and morphometry in piglets weaned at 7 days of age. effects of level of energy intake

Two trials involving a total of 56 pigs were conducted to examine the effects of weaning at 7 d of age (trial 1) and of energy intake level and length of post-weaning underfeeding period (trial 2) on small intestinal (SI) development and morphometry. At 3 d after weaning, weight of the SI and mucosa (g/kg body weight) and villous height along SI were reduced by 20, 36 and 41%, respectively, compared to the day of weaning. Intestinal morphometrical changes are dependent on SI site and days post-weaning. Villous atrophy on d 3 and recovery on d 14 post-weaning were greater and occurred earlier in the proximal than in the medial and distal SI. Villous height was dependent on the level of energy intake which explains 56% of the variations in proximal SI villous height in weaned pigs and 73% when data of the sow-reared pigs were included in the analysis. Moreover, after 4 d of refeeding, underfed piglets showed similar villous characteristics to piglets fed a continuously high feeding level after weaning stressing that capacities of intestinal restoration were not affected by the length of the post-weaning underfeeding period. Overall, the present results suggest a spatial and temporal effect of weaning on villous atrophy and recovery, and that the level of energy intake is a major factor accounting for the post-weaning villous height.     

Effects of pre-weaning housing in a multi-suckling system on performance and carbohydrate absorption of relatively light and heavy piglets around weaning

The low feed intake and stress associated with abrupt weaning in conventional pig farming often result in poor post-weaning performance, which is related to impaired intestinal function. We investigated effects of housing conditions before weaning on performance around weaning of relatively light and heavy piglets. Before weaning, piglets were housed either with five sows and their litters in a multi-suckling (MS) system or in pens with individually housed sows in farrowing crates (FC). After weaning at 4 weeks of age (day 0), 16 groups of four piglets (two light and two heavy litter-mates) were housed under equal conditions in enriched pens. Mannitol (day −5 and day 5) and galactose (day 5) were orally administered as markers for gastrointestinal carbohydrate absorption, and after 20 min a blood sample was taken (sugar absorption test). In addition, BW, feed intake and faecal consistency as an indicator for diarrhoea, were assessed frequently during 2 weeks post-weaning. Pre-weaning housing, weight class and their interaction did not affect post-weaning faecal consistency scores. Weight gain over 2 weeks did not differ between pre-weaning housing treatments, but MS piglets gained more (0.67±0.12 kg) than FC piglets (0.39±0.16 kg) between days 2 and 5 post-weaning, P=0.02), particularly in the ‘heavy’ weight class (interaction, P=0.04), whereas feed intake was similar for both treatments. This indicates a better utilisation of the ingested feed of the MS piglets compared with the FC piglets in the early post-weaning period. Pre-weaning mannitol concentrations were unaffected by pre-weaning housing, weight class and their interaction. On day 5 post-weaning, however, MS piglets had a lower plasma concentration of mannitol (320 v. 592 nmol/ml, SEM=132, P=0.04) and galactose (91 v. 157 nmol/ml, SEM=20, P=0.04) than FC piglets, regardless of weight class. In conclusion, MS and FC piglets differed in aspects of post-weaning gastrointestinal carbohydrate absorption and in weight gain between days 2 and 5 after weaning, but pre-weaning housing did not affect feed intake, weight gain and measures of faecal consistency over the first 2 weeks after weaning.     

Tissue-specific profiling reveals modulation of cellular and mitochondrial oxidative stress in normal- and low-birthweight piglets throughout the peri-weaning period

Weaning is known to induce important nutritional and energetic stress in piglets. Low-birthweight (LBW) piglets, now frequently observed in swine production, are more likely to be affected. The weaning period is also associated with dysfunctional immune responses, uncontrolled inflammation and oxidative stress conditions that are recognized risk factors for infections and diseases. Mounting evidence indicates that mitochondria, the main cellular sources of energy in the form of adenosine 5′ triphosphate (ATP) and primary sites of reactive oxygen species production, are related to immunity, inflammation and bacterial pathogenesis. However, no information is currently available regarding the link between mitochondrial energy production and oxidative stress in weaned piglets. The objective of this study was to characterize markers of cellular and mitochondrial energy metabolism and oxidative status in both normal-birthweight (NBW) and LBW piglets throughout the peri-weaning period. To conduct the study, 30 multiparous sows were inseminated and litters were standardized to 12 piglets. All the piglets were weighted at day 1 and 120 piglets were selected and assigned to 1 of 2 experimental groups: NBW (n = 60, mean weight of 1.73 ± 0.01 kg) and LBW piglets weighing less than 1.2 kg (n = 60, 1.01 ± 0.01 kg). Then, 10 piglets from each group were selected at 14, 21 (weaning), 23, 25, 29 and 35 days of age to collect plasma and organ (liver, intestine and kidney) samples. Analysis revealed that ATP concentrations were lower in liver of piglets after weaning than during lactation (P < 0.05) thus suggesting a significant impact of weaning stress on mitochondrial energy production. Oxidative damage to DNA (8-hydroxy-2′-deoxyguanosine, 8-OHdG) and proteins (carbonyls) measured in plasma increased after weaning and this coincides with a rise in enzymatic antioxidant activity of glutathione peroxidase (GPx) and superoxide dismutase (SOD) (P < 0.05). Mitochondrial activities of both GPx and SOD are also significantly higher (P < 0.05) in kidney of piglets after weaning. Additionally, oxidative damage to macromolecules is more important in LBW piglets as measured concentrations of 8-OHdG and protein carbonyls are significantly higher (P < 0.05) in plasma and liver samples, respectively, than for NBW piglets. These results provide novel information about the nature, intensity and duration of weaning stress by revealing that weaning induces mitochondrial dysfunction and cellular oxidative stress conditions which last for at least 2 weeks and more severely impact smaller piglets.     

Relationships between individual behavioural traits and post-weaning growth in segregated early-weaned piglets

Piglets' individual behavioural traits have been studied in the last decade but no report has linked these traits with growth. This experiment was conducted to determine if behavioural traits of segregated early-weaned piglets could be good predictors of their post-weaning growth and, thus, help to predict their adaptation to early weaning. Following segregated early weaning at 17+/-1 days old, 252 piglets were submitted to three tests between 20 and 25 days of age: open-field, reaction to humans and rank order based on competition for a restricted-access feeder. The body weight of each piglet was measured the day before weaning and once a week for the next 4 weeks. A principal component analysis yielded five factors with an Eigenvalue higher than 0.90 that accounted for 81% of the total variation between individuals: reaction to humans (25%), active response to stress (21%), passive response to stress (14%), feeding behaviour (10%) and rank order (9%). Passive reaction to stress was associated with better weight gain during the first week post-weaning (r=0.18; P=0.01), and a positive correlation was found between social status and weight gain during the 4 weeks following weaning (-0.15相似文献   

Blood markers of oxidative stress predict weaning failure from mechanical ventilation

Patients undergoing mechanical ventilation (MV) often experience respiratory muscle dysfunction, which complicates the weaning process. There is no simple means to predict or diagnose respiratory muscle dysfunction because diagnosis depends on measurements in muscle diaphragmatic fibre. As oxidative stress is a key mechanism contributing to MV‐induced respiratory muscle dysfunction, the aim of this study was to determine if differences in blood measures of oxidative stress in patients who had success and failure in a spontaneous breathing trial (SBT) could be used to predict the outcome of MV. This was a prospective analysis of MV‐dependent patients (≥72 hrs; n = 34) undergoing a standard weaning protocol. Clinical, laboratory and oxidative stress analyses were performed. Measurements were made on blood samples taken at three time‐points: immediately before the trial, 30 min. into the trial in weaning success (WS) patients, or immediately before return to MV in weaning failure (WF) patients, and 6 hrs after the trial. We found that blood measures of oxidative stress distinguished patients who would experience WF from patients who would experience WS. Before SBT, WF patients presented higher oxidative damage in lipids and higher antioxidant levels and decreased nitric oxide concentrations. The observed differences in measures between WF and WS patients persisted throughout and after the weaning trial. In conclusion, WF may be predicted based on higher malondialdehyde, higher vitamin C and lower nitric oxide concentration in plasma.     

The effect of supplementation with an antioxidant preparation on LDL-oxidation is determined by haptoglobin polymorphism

The genetic polymorphism of haptoglobin (Hp) is an independent risk factor in the pathogenesis of atherosclerosis, a condition in which decreased resistance to in vitro oxidation of LDL-cholesterol is observed. We hypothesised that the Hp polymorphism is one of the factors modulating the resistance to Cu(2+)-induced oxidation of LDL during antioxidant supplementation. In this study, 74 middle-aged subjects with increased oxidative stress were allocated to either matched placebo or oral antioxidative treatment (Quatral) once daily for 16 weeks. Study parameters were increase of lag phase (DeltaLAG) and the ratio of lag phase during treatment period versus baseline (relative oxidation resistance, ROR), measured by Cu(2+)-induced oxidation of isolated LDL. Hp phenotypes were determined by starch gel electrophoresis. A significant and persistent increase of DeltaLAG (P < 0.05) and ROR (P < 0.01) were observed after 16 weeks of active treatment versus placebo. Interindividual differences in both parameters were significantly associated with the Hp polymorphism: in the active treatment group, DeltaLAG and ROR were significantly higher in Hp 1-1 subjects (P < 0.01) compared to Hp 2-1 and 2-2. Our data demonstrate that Hp phenotype is one of the modulating factors determining the increased resistance to Cu(2+)-induced oxidation of LDL during antioxidative treatment.     

Effect of a bovine colostrum whey supplementation on growth performance, faecal Escherichia coli population and systemic immune response of piglets at weaning

This study examined the effect of a bovine colostrum whey supplementation on growth performance, feed intake, faecal Escherichia coli population and systemic immune response of piglets at weaning. A total of 96 piglets weaned at 26 ± 2 days of age were assigned for 4 weeks to one of the two treatments: (1) the control (commercial diet with bovine milk whey powder) and (2) the colostrum (commercial diet with freeze-dried bovine colostrum whey) treatments. The two supplements were incorporated in the diet at a level of 20 g/kg during the first 2 weeks after weaning and lowered to a level of 10 g/kg for the next 2 weeks. BW and feed intake were measured weekly. Faecal E. coli counts were determined weekly on specific culture media. Blood samples were collected weekly and submitted to a cell counter analyser for their main components (red and white blood cells, platelets) and flow cytometry was used to determine the lymphocyte population (B, T, Th and Tc). Finally, total seric immunoglobulin (IgM, IgG and IgA) concentrations were determined by the ELISA method. During the first week of the trial, the piglets from the colostrum treatment had improved average daily gain (170 g/day v. 81 g/day, P < 0.001), average daily feed intake (346 g/day v. 256 g/day, P = 0.03) and feed efficiency (BW gain/feed intake) (0.48 v. 0.31, P = 0.04). The pigs fed the colostrum treatment had also a 25% increase in circulating IgA (P = 0.03) compared with the control treatment the first week. It is concluded that a distribution of bovine colostrum whey (20 g/kg diet) during the first week post-weaning induces a systemic IgA response and has a beneficial action on growth performances and feed efficiency.     

Effect of dietary fat or starch supply during gestation and/or lactation on the performance of sows, piglets' survival and on the performance of progeny after weaning

Two trials were carried out to compare the effects of fat or starch inclusion in sow's diet on sow and litter performance. In each trial, sows were assigned to one of two treatments. In trial 1, the sows were fed diets containing either soybean oil (5%, treatment GL5) or cornstarch (11.3%, GL0) from day 35 of gestation to weaning. Daily net energy and nutrient allowance were equalised during gestation. In trial 2, the same treatments were applied only after farrowing (treatments L5 and L0, respectively). Within each trial, a batch of piglets was studied until slaughter. In trial 1, adipose cell development and total lipid content were determined on some pigs at weaning (n = 6/treatment) and at slaughter in dorsal subcutaneous adipose tissue (n = 13/group at least) and in muscle (n = 46/group at least). Piglets' birth weight was not affected by treatment in trial 1. Survival rates at birth and after 24 h of life were higher in treatment GL5 (4.0% v. 7.5% stillborn piglets in GL0 treatment, P < 0.05; 8.7% v. 12.6% of piglets alive at 24 h of age died in treatment GL0, P = 0.06). Subsequently, overall survival rate until weaning was higher in treatment GL5 (81.4% v. 75.7% of total born piglets, P = 0.03), but litter size at weaning was not significantly affected (11.3). Litter growth rate before weaning was increased when a fat-enriched diet was provided during gestation and lactation (+140 g/day per litter; P < 0.01) and to a lower extent when provided only after farrowing (+90 g/day; P < 0.05). Energy supply through fat did not decrease the mobilisation of the sow's body reserve and backfat thickness loss was even higher with treatment GL5 (P < 0.05). After weaning, pigs' average daily gain, feed : gain ratio and carcass lean content were not affected by the energy source supplied before and/or after farrowing. At weaning, the number of adipose cells in the dorsal subcutaneous adipose tissue and in the Longissimus dorsi muscle was higher in the GL5 pigs. Muscle lipid content at weaning did not differ between treatments, but it was higher at slaughter, around 110 kg, in the GL5 pigs (3.46% v. 2.58%, P < 0.001).     

Effect of milk deprivation during the lactation period on performance and digestive enzyme activities of the piglets following weaning

Post-weaning performance of piglets from systems where lactation is disrupted (e.g. from multisuckling systems) is superior to conventionally reared piglets. The objective of this study was to establish whether restricted growth prior to weaning caused by disruption of suckling was an important factor in post-weaning performance and also whether there were related changes in gastro-intestinal development. Ten litters of eight piglets were used in a split-plot design. Half of each litter (limited suckling, LS) had suckling disrupted by separation from their dam for 7 h/day from day 14 to 28 after farrowing. The remainder of each litter was allowed to suck normally (normal suckling, NS). The same amount of creep feed was offered to LS piglets as consumed by NS littermates on the previous day. There were no differences in weight between LS and NS piglets at 14 days of age, but restricting access to the sow reduced weaning weight at 28 days of age (7.96 v. 9.00 kg; LS v. NS; P < 0.01; s.e.d. 0.23). Feed intakes were greater for LS than NS piglets over the first 28 days post weaning, particularly in the 1st week after weaning when feed efficiency was also improved (0.91 v. 0.62 kg gain per kg feed; P < 0.01; s.e.d. 0.08). As a result, LS piglets grew more rapidly in the first 28 days post weaning, particularly in the first 7 days after weaning. Subsequent performance to 8 weeks was similar for both groups. Digestive organ weights were not different at 2 and 9 days after weaning; nor were small intestine specific enzyme activities significantly different ( P>0.05). Pancreatic trypsin activity was, however, greater ( P < 0.01) for LS pigs on both days 2 and 9 post weaning. In conclusion the restriction of growth as a result of limited suckling itself is an important factor in determining post-weaning performance and may be related to development of pancreatic trypsin activity.     

饲粮中添加杜仲叶对断奶仔猪生长性能、抗氧化力和免疫功能的影响

在断奶仔猪饲粮中添加不同形式的杜仲叶,研究其对仔猪生长性能、腹泻率、抗氧化力及免疫功能的影响,以评估它们在养殖初期替代抗生素的能力。将断奶仔猪(杜×长×大)随机分成对照组、抗生素组(75 mg/kg金霉素)和三个杜仲叶组(杜仲叶提取物、发酵杜仲叶、杜仲叶干粉),每组10头,进行28天养殖试验。结果表明:与对照相比,杜仲叶提取物组仔猪平均日增重(ADG)显著提高并降低料重比(F/G)(P<0.05);与抗生素组相比,杜仲叶提取物组和杜仲叶发酵组ADG和F/G均无显著差异(P>0.05);各组之间平均日采食量(ADFI)差异不显著(P>0.05)。与对照组相比,抗生素组和杜仲叶提取物组仔猪腹泻率显著降低(P<0.05)。与对照组相比,抗生素组和三种杜仲叶组均降低仔猪血液丙二醛含量和提高总抗氧化力(P<0.01),而抗生素组、杜仲叶提取物组和杜仲叶发酵组还显著提高血液免疫球蛋白IgM含量(P<0.01),且表现出提高血液IgG含量的趋势(P=0.06)。与其他各组相比,杜仲叶提取物组可显著提高肝脏指数(P<0.05);肝脏重量、脾脏重量和脾脏指数在各组之间无显著差异(P>0.05)。饲粮中添加杜仲叶提取物可改善断奶仔猪的生长性能,降低腹泻率,提高仔猪抗氧化力和免疫功能,其效果优于发酵杜仲叶和杜仲叶干粉,并具备一定的抗生素替代潜力。     

The effect of zinc oxide supplementation on the stability of the intestinal flora with special reference to composition of coliforms in weaned pigs

The effect of a dietary supplementation of zinc oxide (ZnO) on the stability of the intestinal flora and on the composition of coliforms in weaned pigs was investigated. Faecal floras were characterized by their metabolic activities and fermentative capacity (FC) using the Phene Plate generalized microplate. Coliforms were characterized by conventional enumeration and by the Phene Plate-RS plates. The latter measured FC, phenotypic diversity, persistence of each coliform strain in piglets, and similarity among the coliform populations within groups. From weaning onwards, the control pigs (n = 5) were fed a basal diet ad libitum, while experimental pigs (n = 5) were given the same food supplemented with 2500 ppm ZnO. Metabolic fingerprinting of faecal floras indicated marked differences between the composition of floras of treated and control pigs during the first 2 weeks post-weaning. The FC of faecal flora in both groups decreased as pigs aged, but it was significantly (P 相似文献   

Piglet growth before and after weaning in relation to a qualitative estimate of solid (creep) feed intake during lactation: a pilot study

The experimental objectives were to verify whether a qualitative measure of creep feed consumption using a dye was related to performance, and associate this with teat order. Indigo carmine (5 g/kg) was added to a starter diet between days 12 and 31 (weaning) of lactation. On days 19, 23, 27 and 31, faeces from each piglet were assessed for colouration. Each piglet was categorized as a 'good', 'moderate' or 'small/non' eater of feed. There were no differences in pre-weaning growth rate between categories. Piglets classed as 'good' or 'moderate' eaters in lactation grew fastest (p = 0.009) in the first three days after weaning, but between days 4 and 7, the highest growth rate occurred in 'moderate' eaters. 'Small/ non' eaters grew slower (p < 0.01) between weaning and 28 days after weaning. Piglets drinking milk from anterior teats were heavier at weaning (p < 0.001) and for the first 14 days after weaning (p = 0.104) compared to piglets sucking posterior teats. Data from this study demonstrated that creep feed intake of piglets could qualitatively be assessed using indigo carmine, and that this categorization was related to performance in the immediate post-weaning period.     

Effects of a bovine colostrum-supplemented diet on some gut parameters in weaned piglets

The present study investigated the effects of a bovine colostrum-supplemented diet on gut post-weaning adaptation and health in piglets. Thirty-six 21-d-old piglets were allocated to one of the three following dietary treatments: sow-reared (SR), weaned on a control starter diet (WCtrl) or on a starter diet supplemented with bovine colostrum (WCol) until slaughter at 28 d or 35 d of age. Gastric pH and intestinal bacteriological, structural and functional parameters were determined. Compared to WCtrl, the gastric pH was lower (P < 0.05) and the duodenal lactobacilli:coliform ratio was higher (P = 0.05) in WCol piglets. The relative small intestine weight was 18% (P < 0.05) higher in WCol piglets than in SR piglets. Duodenal villous height was lower (P < 0.01) in WCtrl than in SR piglets, whereas the value for WCol piglets was intermediate. The weaning-increased crypt cell proliferation was not affected by bovine colostrum supplementation. The mucosal ribosomal capacity was higher (P < 0.05) in W than in SR piglets. In conclusion, a diet supplemented with colostrum induced, although not always significantly, variations of gut parameters, suggesting that globally, colostrum may limit weaning-induced gut structural and microbial alterations. The observed effects occurred early and were maintained throughout the post-weaning adaptive phase.     

Effect of oral polyamine supplementation pre-weaning on piglet growth and intestinal characteristics

A high proportion of piglets fail to adapt to the changing composition of their diet at weaning, resulting in weight loss and increased susceptibility to pathogens. Polyamines are present in sow milk and promote neonatal maturation of the gut. We hypothesised that oral spermine and spermidine supplementation before weaning would increase piglet growth and promote gastrointestinal development at weaning. In Experiment One, one pair of liveweight (LW)-matched piglets per litter from first and third lactation sows received 2 ml of a 0 (Control) or 463 nmol/ml spermine solution at 14, 16, 18, 20 and 22 days of age (n=6 piglets/treatment per parity). Villus height and crypt depth in the duodenum and jejunum were measured at weaning (day 23 postpartum). In Experiment Two, piglets suckling 18 first and 18 third lactation sows were used. Within each litter, piglets received 2 ml of either water (Control), 463 nmol/ml spermine solution or 2013 nmol/ml spermidine solution at 14, 16, 18, 22 and 24 days of age (n=54 piglets/treatment per sow parity). Piglets were weighed individually at 14, 18, 24 (weaning) and 61 days of age. In Experiment One, oral spermine supplementation resulted in a 41% increase in villus height, a 21% decrease in crypt depth and 79% decrease in the villus height : crypt depth ratio compared with control piglets (P<0.01). In Experiment Two, spermine and spermidine-supplemented piglets suckling first lactation sows grew faster (P<0.05) between days 14 and 18 postpartum than control piglets: 0.230±0.011 and 0.227±0.012 v. 0.183±0.012 kg/day, respectively. Spermine supplementation tended (P<0.1) to increase piglet LW gain from weaning to day 37 post-weaning compared with control piglets (0.373±0.009 v. 0.341±0.010 kg/day). In conclusion, spermine supplementation increased villus height at weaning, and appears to have the potential to improve the pre- and post-weaning growth of conventionally weaned piglets.     

The effect of a diet with fructan-rich chicory roots on intestinal helminths and microbiota with special focus on Bifidobacteria and Campylobacter in piglets around weaning

The restrictions on the use of antibiotic and anthelmintic treatments in organic pig farming necessitate alternative non-medical control strategies. Therefore, the antibiotic and parasite-reducing effect of a fructan-rich (prebiotic) diet of dried chicory was investigated in free-ranging piglets. Approximately half of 67 piglets from nine litters were experimentally infected with Ascaris suum and Trichuris suis in the suckling period (1 to 7 weeks of age) and 58 of the piglets were challenged daily with Eschericia coli O138:F8 for 9 days after weaning to induce weaning diarrhoea. The litters were fed either chicory (30% dry matter) or a control diet. The effect of chicory on intestinal helminths, intestinal microbiota, especially Bifidobacteria and Campylobacter spp. and E. coli post-weaning diarrhoea was assessed. The weight gain of the piglets was not impaired significantly by chicory. The intestinal A. suum worm burden was reduced by 64% (P = 0.034) in the chicory-fed piglets, whereas these same piglets had 63% more T. suis worms (P = 0.016). Feeding with chicory elicited no changes among the main bacterial groups in ileum according to terminal restriction fragment length polymorphism analysis. However, the terminal-restriction fragment (T-RF) 208 bp, which may belong to Lachnospiraceae, was stimulated by the chicory feed (P = 0.03), and T-RF 370 bp that matches Enterobacter belonging to the Enterobacteria was reduced (P = 0.004). In addition, chicory increased the level of Bifidobacteria (P = 0.001) and the faecal Campylobacter excretion level was transitorily reduced in chicory-fed piglets at 7 weeks of age (P = 0.029). Unfortunately, it was not possible to assess the effect of chicory on post-weaning diarrhoea as it did not develop. In conclusion, feeding piglets chicory around the time of weaning caused complex changes of the microbiota and parasite communities within the intestinal tract, and feeding piglets chicory may therefore serve as an animal-friendly strategy to control pathogens.     

A glucocorticoid receptor agonist improves post-weaning growth performance in segregated early-weaned pigs

While beneficial for sow reproductive efficiency and biosecurity, segregated early weaning (SEW) leads to a systemic immune response that adversely affects the digestive physiology and post-weaning growth of pigs. Two experiments were conducted to evaluate the effects of a glucocorticoid receptor agonist (GA) on growth performance, measures of immune function and intestinal integrity of SEW pigs. In both experiments, pigs were fed corn-soybean meal-based starter diets. In the first experiment, 48 pigs (initial BW 4.8 ± 0.7 kg) were weaned at 21 ± 1 days and randomly assigned to three GA treatment groups: 0, 0.2 and 0.6 mg GA/kg of BW injected intramuscularly. Treatments were administered one day before weaning. Pigs in the 0 mg GA group received sterile saline in place of GA. Body weight was measured daily from one day before to 7 days post-weaning, and then weekly until 28 days post-weaning. Piglets treated with 0.2 mg GA had a higher BW than piglets in other treatment groups during the 28-day course of the study (P <0.02). To further explore the mechanisms behind this result, a second experiment was performed in which a total of 18 gilts (BW 5.6 ± 0.85 kg) were randomly assigned into three treatment groups: suckling plus saline (UWS), weaned treated with GA (WGA; 0.2 mg GA/kg BW) and weaned plus saline (CON). Treatments were administered one day before and 3 days post-weaning. The WGA and CON groups were weaned at 23 ± 2 days, while the UWS group remained with sow for the duration of the study. Body weight was measured daily and blood plasma was collected at 0, 1, 4 and 5 days post-weaning. All gilts were euthanized 5 days after weaning and jejunum samples were collected for mucosal scrapings, histomorphological analysis and gene expression analysis. Plasma levels of interleukin-1β (IL-1β) and haptoglobin were lower in WGA pigs compared with CON (P <0.02), while plasma total antioxidant capacity was higher in WGA pigs compared with both CON and UWS groups (P <0.01). Relative to CON, GA downregulated IL-18 gene expression in the jejunum, as assessed by both tissue homogenate and mucosal scrapings, but it upregulated claudin-IV gene expression only in the tissue homogenate (P <0.01). These results suggest that GA treatment improves the growth performance of SEW pigs in part by mitigating the negative effects of systemic inflammation. However, the effect of GA on barrier integrity requires further investigation.     

Reproductive Performance of Sows Supplemented with Dietary L-carnitine over Three Reproductive Cycles

The effect of L-carnitine supplementation during pregnancy and lactation on the reproductive performance of sows was studied in two separate trials over three reproductive cycles. Both trials were identical in design and conduct but were performed with different animals. The trials comprised of a total of 127 sows (trial 1) and 100 sows (trial 2) which were divided into control and treatment groups. All animals were fed individually and received basic feed mixtures with low native carnitine concentrations. The rations of the sows in the treated group were supplemented with 125mg L-carnitine per head and day during pregnancy and 250mg L-carnitine per head and day during lactation. The animals of the control group received identical feed mixtures in identical amounts, but without the L-carnitine supplement. In the first trial, 212 litters were produced and evaluated for number and body weight of the animals, in the second trial, 173 litters were produced. L-carnitine supplementation significantly increased body weight gains of the sows between day 1 and day 85 of weaning. The number of born piglets, stillborn piglets and piglets fit for rearing was not influenced by dietary L-carnitine supplementation. However, L-carnitine supplementation significantly increased the weights of piglets and litters at birth, weight gains of litters during suckling and weights of litters at weaning. These effects of L-carnitine were seen in both trials; they were independent of the age of the sows and remained over three reproductive cycles in which the sows where continuously treated with L-carnitine. Overall, the study shows that dietary supplementation with L-carnitine during pregnancy and lactation improves the reproductive performance of sows over several reproductive cycles, independent of the age of the sows.