Weaning Piglets Research Articles

144 Effect of Protein Source on Piglet Performance and Dietary Protein Digestibility in Regular Nursery and Escherichia Coli Challenged Conditions

Abstract Compared with conventional soybean meal (SBM), processed soy protein has been demonstrated to have greater nutrient digestibility, leading to better animal growth performance and gut health. The aim of the present study was to test hypothesis that Provisoy, a SBM product produced via hydrothermal mechanical treatment could improve weaning piglet growth performance via greater crude protein (CP) digestibility compared with SBM, and this benefit would be greater in pigs under Escherichia coli (ETEC) challenged conditions. A total of 268 weaned pigs [initial body weight (BW) = 6.82 ± 0.85 kg] were allotted to a split plot design and pigs were housed in either a regular nursery condition (5 pigs/pen, 10-11 pens/treatment) or an ETEC challenged condition (3 pigs/pen, 12 pens/treatment, 1 pig per pen was orally gavaged with 10 mL O149K91K88 on d 5 post-weaning). All pigs were fed one of the following diets: SBM, Provisoy or HP300. A standard wheat-barley-SBM based nursery diet was used and test soy products were added to replace SBM in the treatment diets. All diets were formulated to be isocaloric and had similar standardized ileal digestible lysine level in a three-phase (38 days) nursery program. One pig per pen was euthanized for ileal digesta and fecal samples were collected on post-weaning day 13 and 14. Data were analyzed by general linear model in R. In summary, there was no interaction between challenge condition and dietary protein source on intake and gain throughout all three phases. A significant interaction in G:F between d 0-7 post-weaning (P < 0.05) was observed. As expected, pigs performed better in regular conditions compared with challenged conditions (P < 0.05). Dietary protein source significantly affected ADG (P < 0.05) and BW (P < 0.01) on post-weaning d 7 regardless of challenge condition, with pigs fed Provisoy exhibiting increased ADG and d 7 BW versus the control but not different than HP300. Similar improvements in growth performance were observed during d 7-12 post-weaning. However, the effect of protein source on piglet growth was no longer evident during the last phase of nursery. There was no interaction observed between challenge condition and protein source on CP apparent ileal digestibility (AID) or apparent total tract digestibility (ATTD). Dietary protein source affected CP ATTD (P < 0.01), with Provisoy treatment having the greatest value compared with other treatments. Challenge conditions tended to decrease CP AID (P = 0.109). In conclusion, dietary inclusion of Provisoy could improve piglet growth performance during the early nursery phase regardless of challenge condition and this benefit was likely partially due to better CP digestibility.

Effects of Enterotoxigenic Escherichia coli Challenge on Jejunal Morphology and Microbial Community Profiles in Weaned Crossbred Piglets.

Pathogenic enterotoxigenic Escherichia coli (ETEC) is a major cause of bacterial diarrhea in weaning piglets, which are vulnerable to changes in environment and feed. This study aimed to determine the effects of the ETEC challenge on piglet growth performance, diarrhea rate, jejunal microbial profile, jejunal morphology and goblet cell distribution. A total of 13 piglets from one litter were selected on postnatal day 21 and assigned to treatments with or without ETEC challenge at 1 × 108 CFUs, as ETEC group or control group, respectively. On postnatal day 28, samples were collected, followed by the detection of serum biochemical indexes and inflammatory indicators, HE staining, PAS staining and 16S rDNA gene amplicon sequencing. Results showed that the growth performance decreased, while the diarrhea rate increased for the ETEC group. The jejunum is the main segment of the injured intestine during the ETEC challenge. Compared with the control, the ETEC group displayed fewer goblet cells in the jejunum, where goblet cells are more distributed at the crypt and less distributed at the villus. In addition, ETEC piglets possessed higher abundances of the genus Desulfovibrio, genus Oxalobacter and genus Peptococus and lower abundances of the genus Prevotella 2, genus Flavonifractor and genus Blautra. In terms of alpha diversity, Chao 1 and observed features indexes were both increased for the ETEC group. Our study provides insights into jejunal histopathological impairment and microbial variation in response to ETEC infection for weaned piglets and is a valuable reference for researchers engaged in animal health research to select stress models.

Effects of weaning on intestinal longitudinal muscle-myenteric plexus function in piglets.

Weaning piglets usually suffer from severe diarrhea (commonly known as postweaning diarrhea, PWD) along with intestinal motility disorder. Intestinal peristalsis is mainly regulated by the longitudinal muscle-myenteric plexus (LM-MP). To understand the relationship between intestinal LM-MP function and the development of PWD, we compared the intestinal electrical activity, and the transcriptional profile of the LM-MP between 21-day-old piglets (just weaned, n=7) and 24-day-old piglets (suffered the most severe weaning stress, n=7). The results showed that 24-day-old piglets exhibited different degrees of diarrhea. A significant increase in the slow-wave frequency in the ileum and colon was observed in 24-day-old piglets, while c-kit expression in the intestinal LM-MPs was significantly decreased, indicating that PWD caused by elevated slow-wave frequency may be associated with loss of c-kit. The real-time quantitative PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) showed that intestinal LM-MPs in 24-day-old piglets may undergo inflammation and oxidative stress. Significant increases in 8-hydroxy-2'-deoxyguanosine and decreases in thioredoxin suggest that weaning may lead to DNA damage in the LM-MP of 24-day-old piglets. In addition, activating transcription factor 3 was significantly upregulated, indicating nerve damage in the LM-MP of 24-day-old piglets. The transcriptomic results showed that most of the differentially expressed genes in the ileal LM-MP after weaning were downregulated and closely related to the cell cycle process. Subsequent RT-qPCR analysis showed that the relative expression of p21 was upregulated, while the expression of cyclin A2, cyclin B1, and proliferating cell nuclear antigen was downregulated in the ileal and colonic LM-MP of 24-day-old piglets, suggesting that weaning may inhibit cell proliferation and cause G1/S cell cycle arrest in ileal and colonic LM-MP. In conclusion, weaning may lead to cell cycle arrest by causing DNA damage in the LM-MP, impairing intestinal motility regulation, and ultimately leading to diarrhea in piglets.

Whole-Genome Sequence and Pathogenicity Analysis of Providencia Heimbachae Causing Diarrhea in Weaned Piglets.

Providencia heimbachae was previously identified in piglets with post-weaned diarrhea and associated with hindlimb paralysis. However, the pathogenic mechanisms and virulence factors of P. heimbachae are not fully known. Whole-genome sequence analysis will be helpful to extend our understanding of the characterization of P. heimbachae at a genomic level. In this study, we sequenced the whole genome of P. heimbachae for the first time using PacBio RS II sequencers and assembled de novo through hierarchical genome assembly process (HGAP). Furthermore, we performed further genome annotation. The genome of P. heimbachae 99101 consists of a circular chromosome (4,262,828bp) and a circular plasmid (231,957bp) with G + C contents of 40.43 and 47.16%, respectively. Genome-wide sequence analysis yielded a total of 286 predicted virulence factors, 178 resistance genes, 17 chaperone protein manipulators of fimbriae, 47 genes involved in the encoding of flagellin, 12 cell membrane-associated virulence genes, 18 Enterobacteriaceae common antigens, etc. Based on genome analysis, we preliminarily confirmed through animal experiments that the capsule was the virulence factor of P. heimbachae causing hindlimb paralysis in animals. Our study provides a genetic basis for further elucidation of the characteristics and functional mechanisms of P. heimbachae as a conditionally pathogenic bacterium, as well as a direction for research into the mechanism of action of P. heimbachae infecting humans, extending knowledge of P. heimbachae as an important zoonotic pathogen.

Dietary supplementation of zinc oxide modulates intestinal functionality during the post-weaning period in clinically healthy piglets

BackgroundTo improve our understanding of host and intestinal microbiome interaction, this research investigated the effects of a high-level zinc oxide in the diet as model intervention on the intestinal microbiome and small intestinal functionality in clinically healthy post-weaning piglets. In study 1, piglets received either a high concentration of zinc (Zn) as zinc oxide (ZnO, Zn, 2,690 mg/kg) or a low Zn concentration (100 mg/kg) in the diet during the post weaning period (d 14–23). The effects on the piglet’s small intestinal microbiome and functionality of intestinal tissue were investigated. In study 2, the impact of timing of the dietary zinc intervention was investigated, i.e., between d 0–14 and/or d 14–23 post weaning, and the consecutive effects on the piglet’s intestinal functionality, here referring to microbiota composition and diversity and gene expression profiles.ResultsDifferences in the small intestinal functionality were observed during the post weaning period between piglets receiving a diet with a low or high concentration ZnO content. A shift in the microbiota composition in the small intestine was observed that could be characterized as a non-pathological change, where mainly the commensals inter-changed. In the immediate post weaning period, i.e., d 0–14, the highest number of differentially expressed genes (DEGs) in intestinal tissue were observed between animals receiving a diet with a low or high concentration ZnO content, i.e., 23 DEGs in jejunal tissue and 11 DEGs in ileal tissue. These genes are involved in biological processes related to immunity and inflammatory responses. For example, genes CD59 and REG3G were downregulated in the animals receiving a diet with a high concentration ZnO content compared to low ZnO content in both jejunum and ileum tissue. In the second study, a similar result was obtained regarding the expression of genes in intestinal tissue related to immune pathways when comparing piglets receiving a diet with a high concentration ZnO content compared to low ZnO content.ConclusionsSupplementing a diet with a pharmaceutical level of Zn as ZnO for clinically healthy post weaning piglets influences various aspects intestinal functionality, in particular in the first two weeks post-weaning. The model intervention increased both the alpha diversity of the intestinal microbiome and the expression of a limited number of genes linked to the local immune system in intestinal tissue. The effects do not seem related to a direct antimicrobial effect of ZnO.

The effects of micelle silymarin on growth performance, nutrient utilisation, and blood profiles of weaning piglets

The effects of micelle silymarin on growth performance, nutrient utilisation, and blood profiles of weaning piglets

Effects of Dietary Valine Chelated Zinc Supplementation on Growth Performance, Antioxidant Capacity, Immunity, and Intestine Health in Weaned Piglets

This study was conducted to investigate the effects of dietary valine chelated zinc (ZnVal) supplementation on growth performance, antioxidant capacity, immunity, and intestine health in weaned piglets. A total of 240 healthy 35-day-old weaned piglets (Duroc × Landrace × Yorkshire, average weight 10.70 ± 0.14 kg) were randomly divided into five groups with six replicate pens and eight piglets per pen. Dietary treatments were a corn–soybean meal basal diet supplemented with 0, 25, 50, 75, and 100 mg/kg ZnVal, respectively. The experiment lasted for 28 days. Results showed that average daily gain (ADG) was increased (P < 0.05) by ZnVal with 75–100 mg/kg supplementation on days 15–28 and with 50–100 mg/kg supplementation on days 1–28. Supplementation of 25–100 mg/kg ZnVal reduced (P < 0.01) the diarrhea rate of weaned piglets on days 1 to 14 and 1 to 28. Dietary supplementation with 25–100 mg/kg ZnVal increased (P < 0.05) copper/zinc-superoxide dismutase (Cu/Zn-SOD) and decreased malonaldehyde (MDA) activities in the serum on day 14 and 28. Supplementation of 25–100 mg/kg ZnVal increased (P < 0.05) glutathione peroxidase (GSH-Px) activity in serum on day 14. Additionally, the supplementation of 75 mg/kg ZnVal significantly increased the activity of superoxide dismutase (SOD) and Cu/Zn-SOD in the liver (P < 0.05). Furthermore, the supplementation of 25–100 mg/kg ZnVal significantly increased the total antioxidant capacity (T-AOC) in the liver (P < 0.05). Higher (P < 0.05) concentrations of IgG in the serum were measured from piglets supplemented with 75–100 mg/kg ZnVal on day 14 and dietary supplementation with 25–100 mg/kg ZnVal increased the level of immunoglobulin G (IgG) in serum on day 28 (P < 0.05). In addition, higher (P < 0.05) concentrations of immunoglobulin A (IgA) in the duodenum and ileum were measured from piglets supplemented with 75 mg/kg ZnVal and the supplementation of 25–100 mg/kg ZnVal also showed a higher (P < 0.05) concentration of immunoglobulin G (IgG) in duodenum. Supplementation of 50–100 mg/kg ZnVal increased the villus height and villus height/crypt depth of jejunum (P < 0.05). Moreover, dietary supplementation with 75–100 mg/kg ZnVal showed a higher (P < 0.05) concentration of zinc in the liver and supplementation of 50–100 mg/kg ZnVal increased (P < 0.05) the concentration of zinc in the heart, spleen, and kidney. In conclusion, the present research showed that supplementation of ZnVal improves growth performance by increasing antioxidant capacity and immunity and regulating intestinal morphology and the optimal inclusion level of ZnVal was 65~80 mg/kg.

Porcine Astrovirus Detection and Characterization in Healthy and Diarrheic Pigs from Haryana, India

Background: Porcine astrovirus (PAstV) is an emerging pathogen detected from the feces of both healthy and diarrheic pigs with limited studies comparing the presence of PAstV and diarrhea in pigs. PAstV has been reported worldwide with a few reports from India. In addition, there are limited reports on variation in the amino acid sequence of the ORF2 region, which codes for viral capsid protein. The present study was aimed to study the presence of PAstV, association with diarrhea in pigs of various age groups and its molecular characterization from Haryana, a northern Indian state. Methods: A total of 176 rectal swabs of pigs were collected from different parts of Haryana. The samples were screened for PAstV by RT-PCR of the partial ORF1b/ORF2 genomic region. The positive samples were characterized by molecular typing and phylogenetic analysis. Result: In the present study, PAstV was detected in pigs in 16.47% of fecal samples, including 21/127 (16.53%) diarrheic and 8/49 (16.32%) non-diarrheic. The results indicated that weaning piglets were more susceptible to PAstV infection followed by suckling piglets. The phylogenetic analysis revealed the circulation of PAstV4 and PAstV2 lineages in Haryana. The study revealed endemic presence of virus in the region with high genetic diversity among the PAstV strains, suggesting a wide range of heterogeneity.

Tert-butylhydroquinone attenuates LPS-induced pyroptosis of IPEC-J2 cells via downregulating HMGB1/TLR4/NF-κB axis.

Inflammatory response induced by biological stress usually occurs in weaning piglets, it reduces the production performance of piglets and even causes death. Tert-butylhydroquinone (TBHQ) is a food additive that has the effect of anti-inflammation and anti-oxidation. However, there are few reports related to the protective mechanisms of TBHQ on lipopolysaccharide (LPS) induced injury in intestinal porcine epithelial (IPEC-J2) cells. Quantitative real-time polymerase chain reaction and western blot analysis, respectively, detected the mRNA levels and protein expressions related to pyroptosis, tight junction (TJ) protein and high-mobility group box 1/toll-like receptor 4/nuclear factor kappa-B (HMGB1/TLR4/NF-κB) axis. Localisation and expression of NOD-like receptor pyrin domain containing 3 (NLRP3), HMGB1 and P-NF-κB proteins detected by immunofluorescence. The results showed that TBHQ (12.5 and 25 μM) can increase cell activity and reduce intracellular lactate dehydrogenase (LDH) levels in a dose-dependent manner. LPS significantly decreases cell viability and increases the LDH level. However, pretreatment with TBHQ evidently increases cell viability and decreases the LDH level of IPEC-J2 cells. In addition, treatment with LPS decreased the mRNA level and protein expression of zonula occludens-1, occludin and claudin-1, and increased the mRNA level and protein expression of pyroptosis and HMGB1/TLR4/NF-κB axis. Interestingly, pretreatment with TBHQ increased the TJ protein expressions as well as decreased the mRNA level and protein expressions of pyroptosis and HMGB1/TLR4/NF-κB axis. Moreover, the results of immunofluorescence showed that TBHQ significantly reduced the expression of NLRP3, HMGB1 and P-NF-κB in LPS-induced injury of IPEC-J2 cells. Therefore, we come to the conclusion that TBHQ attenuates LPS-induced pyroptosis in IPEC-J2 cells through downregulation of the HMGB1/TLR4/NF-κB axis, TBHQ may become a potential feed additive for preventing inflammatory diarrhoea in piglets.

71 (P7-1). Dietary BSF-Oil improves weaning piglets feces score and productivity under commercial conditions

71 (P7-1). Dietary BSF-Oil improves weaning piglets feces score and productivity under commercial conditions

Maternal sodium acetate supplementation promotes lactation performance of sows and their offspring growth performance.

Milk yield and composition are critical determining factors for the early growth and development of neonates. The objective of this experiment was to comprehensively evaluate the effects of dietary sodium acetate (SA) supplementation on the milk yield and composition of sows and the growth performance of their offspring. A total of 80 sows (Landrace×Yorkshire, 3 to 6 parity) were randomly assigned to 2 groups (with or without 0.1% SA) from d 85 of gestation to d 21 of lactation. The result shows that maternal 0.1% SA supplementation significantly increased sows milk yield, milk fat, immunoglobulin A (IgA) and IgG content in milk (P<0.05), with the up-regulation of short-chain fatty acids receptors (GPR41 and GPR43) expression and the activation of mammalian target of rapamycin complex C1 (mTORC1) signaling pathway. Consistently, in our invitro experiment, SA also activated mTORC1 signaling in porcine mammary epithelial cells (P<0.05). Furthermore, the improvement of milk quality and quantity caused by maternal SA supplementation led to the increase in body weight (BW) and average daily weight gain (ADG) of weaning piglets, with the improvement of gut health and colonization of the beneficial bacteria (P<0.05). In conclusion, maternal supplementation of 0.1% SA improved the lactation performance (milk yield and milk fat) of sows, possibly with the activation of GPR41/GPR43-mTORC1 signaling. Furthermore, enhanced milk quality improved growth performance, gut health and the colonization of beneficial microbial flora of their piglets.

Mesobiliverdin IXα-enriched microalgae feed additive eliminates reliance on antibiotic tylosin to promote intestinal health of weaning piglets.

Weaning is a critical period in raising pigs. Novel animal feed additives that promote gut health and regulate immune function of piglets without antibiotics are needed. In this study, we aimed to test the ability of mesobiliverdin IXα-enriched microalgae (MBV IXα-enriched microalgae) to eliminate reliance on antibiotics to promote intestinal health in piglets. Eighty 28-day-old weaned piglets were randomly allocated to four groups each with fourreplicate pens and fivepiglets per pen. The dietary treatments were a basal diet as control (NC), basal diet plus 0.05% tylosin (PC), basal diet plus 0.1% or 0.5% MBV IXα-enriched microalgae as low (MBV-SP1) or high (MBV-SP2) dose respectively. All treated animals showed no significant differences in live weight, average daily gain and feed efficiency compared to control animals. Histological examination showed that MBV-SP1 and particularly MBV-SP2 increased the ratio of villus height to crypt depth in the jejunum and ileum compared to NC (p < 0.05). Similarly, tylosin treatment also increased villi lengths and the ratio of villus height to crypt depth in the jejunum and ileum compared to the NC (p < 0.05). MBV-SP1 and particularly MBV-SP2 reduced the levels of inflammatory cytokines interleukin-6 and tumour necrosis factor-alpha in the small intestine. MBV-SP2 and tylosin similarly reduced the lipid peroxidation marker (TBARS value) in the duodenum and ileum. In conclusion, feed supplementation with MBV IXα-enriched microalgae improved gut health by villus height and production of immunomodulators that correlated with down-regulated secretion of inflammatory cytokines.

Maternal Supplementary Tapioca Polysaccharide Iron Improves the Growth Performance of Piglets by Regulating the Active Components of Colostrum and Cord Blood.

The purpose of this study was to investigate the effect of maternal supplementation with TpFe (tapioca polysaccharide iron) on reproductive performance, colostrum composition, cord blood active components of sows, and growth performance of their nursing piglets. Sixty healthy Duroc × Landrace × Yorkshire sows were randomly assigned to three groups at day 85 of gestation. The experimental diets included a basal diet supplemented with 100 mg/kg FeSO4·H2O (CON group), the basal diet supplemented with 50 mg/kg TpFe (TpFe50 group), and the basal diet supplemented with 100 mg/kg TpFe (TpFe100 group), as calculated by Fe content. The experiment lasted from day 85 of gestation to the end of weaning (day 21 of lactation). Results showed that maternal supplementation with 100 mg/kg TpFe improved (p < 0.05) feed intake during lactation, live births, and birth weight of the litter (alive) and increased (p < 0.05) colostrum IgM (immunoglobulin m), IgA (immunoglobulin A), as well as the IgG levels, while it decreased (p < 0.05) the urea nitrogen and somatic cell count of sows. Moreover, sows in the TpFe100 group had higher (p < 0.05) serum iron levels and IgG. Additionally, maternal supplementation with 100 mg/kg TpFe increased (p < 0.05) iron level, total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-px), catalase (CAT), IgG, red blood cells (RBC), and hemoglobin (Hb) of cord blood, similar with the iron content, T-AOC, GSH-px, IgG, RBC, Hb, hematocrit (HCT), and mean corpuscular volume (MCV) of weaned piglet blood. The diarrhea and mortality rates among the nursing piglets were decreased (p < 0.05), while the average weight at day 21 of age was increased (p < 0.05) in the TpFe100 group. Serum PRL (prolactin) levels of sows exhibited a positive correlation (p < 0.05) with live births. Suckling piglet diarrhea was positively correlated with colostrum urea nitrogen level but negatively correlated with colostrum IgM, IgG, and cord blood Hb content (p < 0.05). The mortality of suckling piglets was negatively correlated with serum iron content and IgM in colostrum, GSH-px, and IgG in cord serum of sows (p < 0.05). The average weight of weaning piglets was positively (p < 0.05) related to colostrum IgM and IgG levels, as well as cord serum RBC counts of sows on day 21. In conclusion, maternal supplementation with TpFe can improve the active components of colostrum and umbilical cord blood and improve the growth performance of suckling piglets.

Effects of glutamine, glutamate, and aspartate on intestinal barrier integrity and amino acid pool of the small intestine in piglets with normal or low energy diet.

Aspartate (asp), glutamate (glu), and glutamine (gln) are the major energy fuels for the small intestine, and it had been indicated in our previous study that the mix of these three amino acid supplementations could maintain intestinal energy homeostasis. This study aimed to further investigate whether the treatment of gln, glu, and asp in low energy diet affects the intestinal barrier integrity and amino acid pool in weaning piglets. A total of 198 weaned piglets were assigned to 3 treatments: control (basal diet + 1.59% L-Ala); T1 (basal diet + 1% L-Gln + 0.5% L-Glu + 0.1% L-Asp); and T2 (low energy diet + 1% L-Gln + 0.5% L-Glu + 0.1% L-Asp). The blood, jejunum, and ileum were obtained on day 5 or on day 21 post-weaning, respectively. Our results showed that T1 and T2 treatments increased the abundances of occludin, claudin-1, and claudin-3 in the small intestine while decreasing the serum diamine oxidase (DAO) and D-lactate levels in weaning piglets. Meanwhile, T1 and T2 treatments significantly increased the positive rate of proliferating cell nuclear antigen (PCNA) of the small intestine, promoting intestinal cell proliferation. We also found that supplementation with glu, gln, and asp improved the serum amino acid pool and promoted ileal amino acid transporter gene expression of slc3a2, slc6a14, and slc7a11 in weaned piglets. Additionally, on day 21 post-weaning, T1 and T2 treatments stimulated the phosphorylation of the mTOR-S6K1-4EBP1 signaling pathway in the small intestine, which may implicate the enhanced protein synthesis rate. In summary, dietary supplementation of gln, glu, and asp was beneficial to the intestinal barrier function and amino acid pool regulation, while the benefits of gln, glu, and asp treatment might be diminished by the low-energy diet. The results demonstrated that the supplementation of gln, glu, and asp under low energy levels was preferentially supplied as the energy fuel to restore the gut barrier function in piglets on day 5 post-weaning. With the increase in age and intestinal maturation (on day 21 post-weaning), gln, glu, and asp supplementation could also show an effect on the regulation of the amino acid pool and protein synthesis.

The influence of genotype and feeding level of gilts on their further reproductive performance

Since the efficiency of pig breeding largely depends on the reproductive ability of sows, one of the promising areas of research in animal husbandry is the study of factors whose correction can improve the fertility and quality of the offspring. Our work purpose was to investigate the effect of gilts’ feeding level, MC4R genotype and interaction of these factors on the reproductive traits pigs after reaching puberty. The object of the study was crossbred pigs obtained as a result of the combination of sows of the Large White breed with boars of the Landrace breed. To carry out the research, the animals were divided into four groups that differed among themselves by the genotype of the melanocortin 4 receptor gene and the level of feeding of the experimental animals. To determine the genotype, the PCR-RFLP method was utilized. Genetic studies were conducted in a certified laboratory of the Institute of Pig Breeding and Agroindustrial Production. The reproductive capacity of the pigs was determined after receiving the farrowing by the following traits: piglets born alive per farrowing (animals), weight of litters of piglets at birth (kg), average weight of piglet at birth (kg), number of weaning piglets (animals), weight of litters of piglets at 28 days (kg), average weight of piglet at 28 days (kg), average daily gain of suckling piglets from 0 to 28 days (g). It was established that the traits of reproductive ability of crossbred Large White × Landrace pigs were affected by the interaction of genotype and feeding factors. When limiting the nutritional value of the daily diet, sows with the AG genotype outperformed those with the GG genotype by 1.2 piglets born alive per farrowing, by 3.0 kg for litter weight at birth, and by 0.1 kg for the average weight of a piglet at birth. The advantage of the AG genotype for average piglet weight at 28 days was even larger. Conversely, in conditions of a high level of feeding, animals with the GG genotype had higher productivity in terms of such traits as piglets born alive per farrowing – by 1.6 animals; weight of litters of piglets at birth – by 4.1 kg; for average weight of piglet at birth – 0.2 kg; by number of weaning piglets – 2.0 animals; by weight of litters of piglets at 28 days – 28.8 kg; for average weight of piglet at 28 days – 1.1 kg and for average daily gain from 0 to 28 days – 34.6 g. In the future, the goal is to develop a system of differentiated rationing of pigs' diets depending on their genotype.

A note on sows' behaviour towards humans during lactation in farrowing pens with short-term fixation and its effects on piglet mortality

The objective of this study was to determine a relationship between sows’ aggressive behaviour towards humans in farrowing pens with space to move freely and its reproductive outcome. A total of 215 crossbred (Large White x Landrace) sows were included in the research. All sows were housed in farrowing pens with movable crates whereby the crate was closed for five days around farrowing. To measure the sows’ behaviour towards a stockperson, the reaction on being separated from her piglets when handled were scored in week 1 and week 4 of lactation in a separation test. Each sow was scored between 1 (not aggressive) and 5 (extremely aggressive). In addition, reproductive performance was documented as piglets born alive, their birth and weaning weight, piglet losses and piglet losses due to crushing. The majority of the sows showed no aggressive behaviour (scores 1 and 2) in both tests (86.7%). However, sows reacted significant more aggressively in week 1 (16.7%) than in week 4 (10.0%; p < 0.05). The sows’ aggression towards the stockperson had a significant influence on piglet losses. Regardless of whether the sows were aggressive only in week 1 or week 4 or at both times, the aggressive sows (scores 3 to 5) lost significantly more piglets than the sows classified as non-aggressive (scores 1 and 2) (20.1% ± 2.83 vs. 14.1% ± 0.89; p < 0.05). Furthermore, aggressive sows tended to crush more piglets compared to non-aggressive sows (8.91% ± 1.98 vs. 5.59% ± 0.63; p = 0.08). These results indicate that aggressive behaviour of sows towards humans cannot be considered equivalent to good maternal behaviour of sows.

Rice bran oil supplementation protects swine weanlings against diarrhea and lipopolysaccharide challenge.

Early weaned piglets suffer from oxidative stress and enteral infection, which usually results in gut microbial dysbiosis, serve diarrhea, and even death. Rice bran oil (RBO), a polyphenol-enriched by-product of rice processing, has been shown to have antioxidant and anti-inflammatory properties both in vivo and in vitro. Here, we ascertained the proper RBO supplementation level, and subsequently determined its effects on lipopolysaccharide (LPS)-induced intestinal dysfunction in weaned piglets. A total of 168 piglets were randomly allocated into four groups of seven replicates (42 piglets each group, (21±1) d of age, body weight (7.60±0.04) kg, and half males and half females) and were given basal diet (Ctrl) or basal diet supplemented with 0.01% (mass fraction) RBO (RBO1), 0.02% RBO (RBO2), or 0.03% RBO (RBO3) for 21 d. Then, seven piglets from the Ctrl and the RBO were treated with LPS (100 μg/kg body weight (BW)) as LPS group and RBO+LPS group, respectively. Meanwhile, seven piglets from the Ctrl were treated with the saline vehicle (Ctrl group). Four hours later, all treated piglets were sacrificed for taking samples of plasma, jejunum tissues, and feces. The results showed that 0.02% was the optimal dose of dietary RBO supplementation based on diarrhea, average daily gain, and average daily feed intake indices in early weaning piglets. Furthermore, RBO protected piglets against LPS-induced jejunal epithelium damage, which was indicated by the increases in villus height, villus height/crypt depth ratio, and Claudin-1 levels, as well as a decreased level of jejunal epithelium apoptosis. RBO also improved the antioxidant ability of LPS-challenged piglets, which was indicated by the elevated concentrations of catalase and superoxide dismutase, and increased total antioxidant capacity, as well as the decreased concentrations of diamine oxidase and malondialdehyde in plasma. Meanwhile, RBO improved the immune function of LPS-challenged weaned piglets, which was indicated by elevated immunoglobulin A (IgA), IgM, β‍‍-defensin-1, and lysozyme levels in the plasma. In addition, RBO supplementation improved the LPS challenge-induced dysbiosis of gut microbiota. Particularly, the indices of antioxidant capacity, intestinal damage, and immunity were significantly associated with the RBO-regulated gut microbiota. These findings suggested that 0.02% RBO is a suitable dose to protect against LPS-induced intestinal damage, oxidative stress, and jejunal microbiota dysbiosis in early weaned piglets.

Effects of zinc oxide and condensed tannins on the growth performance and intestinal health of weaned piglets in ETEC-challenged environment.

This experiment was conducted to evaluate effects of zine oxide (ZnO) and condensed tannins (CT), independently or in combination, on the growth performance and intestinal health of weaned piglets in enterotoxigenic Escherichia coli (ETEC-K88)-challenged environment. Randomly divided 72 weaned piglets into 4 groups. Dietary treatments included the following: basic diet group (CON), 1,500 mg/kg zinc oxide group (ZnO), 1,000 mg/kg condensed tannins group (CT), and 1,500 mg/kg zinc oxide +1,000 mg/kg condensed tannins group (ZnO + CT). Dietary ZnO supplementation decreased diarrhea rate from 0 to 14 days, 15 to 28 days, and 0 to 28 days (p < 0.05) and no significant on growth performance. The effect of CT on reducing diarrhea rate and diarrhea index was similar to the results of ZnO. Compared with the CON group, ZnO increased the ileum villus height and improved intestinal barrier function by increasing the content of mucin 2 (MUC-2) in jejunum and ileum mucosa and the mRNA expression of zonula occludens-1 (ZO-1) in jejunum (p < 0.05) and the expression of Occludin in duodenum and ileum (p < 0.05). The effects of CT on intestinal barrier function genes were similar to that of ZnO. Moreover, the mRNA expression of cystic fibrosis transmembrane conductance regulator (CFTR) in jejunum and ileum was reduced in ZnO group (p < 0.05). And CT was also capable of alleviating diarrhea by decreasing CFTR expression and promote water reabsorption by increasing AQP3 expression (p < 0.05). In addition, pigs receiving ZnO diet had higher abundance of phylum Bacteroidetes, and genera Prevotella, and lower phylum Firmicutes and genera Lactobacillus in colonic contents. These results indicated that ZnO and CT can alleviate diarrhea and improve intestinal barrier function of weaned pigs in ETEC-challenged environment. In addition, the application of ZnO combined with CT did not show synergistic effects on piglet intestinal health and overall performance. This study provides a theoretical basis for the application of ZnO in weaning piglet production practices, we also explored effects of CT on the growth performance and intestinal health of weaned piglets in ETEC-challenged environment.

A field study of Bacillus licheniformis-fermented products on growth performance and faecal microbiota of weaning piglets

This study investigated the effects of Bacillus licheniformis-fermented products (BLFPs) on the growth performance, faecal microbiota, and antibiotic resistance gene (ARG) expression in weaning piglets on a commercial farm. Ninety-six weaning piglets were randomly assigned to four treatments as follows: basal diet as control (C), basal diet plus 30 mg/kg of antibiotics (bacitracin methylene disalicylate) (A), basal diet plus 1 g/kg of BLFPs (F), and basal diet plus 15 mg/kg of antibiotics and 0.5 g/kg of BLFPs (AF), with six replicate pens per treatment and four pigs per pen. Results showed that, similar to antibiotics, replacing all or half the antibiotics with BLFPs improved the feed conversion ratio of weaning piglets from 15–28 d. Microbiota analysis showed that microbial community composition in the faeces showed a clear separation between groups. Replacing all the antibiotics with BLFPs increased the abundance of the genus, Streptococcus, in the faeces compared with the other groups. Half replacement of antibiotics with BLFPs increased the chloramphenicol resistance gene levels in the faeces compared with the C group, whereas full replacement of antibiotics with BLFPs reduced the streptomycin resistance gene levels compared with the C group. A trend of decreased levels of formic acid and acetic acid was observed in the group treated with BLFPs in combination with antibiotics compared with the C group. In conclusion, the field study demonstrates that replacing all or half the antibiotics with BLFPs can improve feed conversion ratio, modulate faecal microbiota, and alter ARG expression in weaning piglets.

An alternative ZnO with large specific surface area: Preparation, physicochemical characterization and effects on growth performance, diarrhea, zinc metabolism and gut barrier function of weaning piglets

High-dose ZnO is widely used to prevent diarrhea and promote growth of weaning piglets, which has led to serious problems of animal toxicity, bacterial resistance and environmental pollution. In this study, a novel alternative ZnO (AZO) was prepared and its physicochemical properties were characterized. Animal experiments were further conducted to evaluate the effects of the ZnO forms, the dose of AZO and the combinations with AZO on the growth performance, diarrhea, zinc metabolism and gut barrier function of weaning piglets. The results showed that the AZO, compared with ordinary ZnO (OZO), nano ZnO (NZO) and porous ZnO (PZO), had the largest surface area and reduced the release of Zn2+ into the gastric fluid. AZO showed better antibacterial activity on Escherichia coli K88, Staphylococcus aureus and Salmonella enteritidis but lower cytotoxicity on porcine intestinal epithelial cells. Animal experiments suggested that low-dose AZO, NZO and PZO (300 mg/kg) improved growth performance and reduced diarrhea in weaning piglets as well as high-dose OZO (3000 mg/kg). Notably, low-dose AZO had the lowest diarrhea incidence. Additionally, low-dose AZO in combination with probiotics improved digestibility and digestive enzyme activities. Low-dose AZO in combination with probiotics also upregulated the expression of the intestinal zinc transporter proteins ZIP4 and DMT1, increased zinc bioavailability, reduced faecal zinc emissions, and avoided zinc overload in the liver and oxidative damage caused by high-dose ZnO. Moreover, low-dose AZO in combination with probiotics improved the gut barrier function of weaning piglets by promoting the expression of tight junction proteins, mucins and antimicrobial peptides and increasing gut microbiota diversity and beneficial Lactobacillus. This study proposed a novel strategy to replace high-dose ZnO and antibiotics with low-dose AZO and probiotics in weaning piglets, which effectively improved growth performance and prevented diarrhea while reducing animal toxicity, bacterial resistance, heavy metal residues and zinc emission pollution.