It is unclear whether improving feed efficiency by selection for low residual feed intake (RFI) compromises pigs' immunocompetence. Here, we aimed at investigating whether pig lines divergently ...selected for RFI had different inflammatory responses to lipopolysaccharide (LPS) exposure, regarding to clinical presentations and transcriptomic changes in peripheral blood cells.
LPS injection induced acute systemic inflammation in both the low-RFI and high-RFI line (n = 8 per line). At 4 h post injection (hpi), the low-RFI line had a significantly lower (p = 0.0075) mean rectal temperature compared to the high-RFI line. However, no significant differences in complete blood count or levels of several plasma cytokines were detected between the two lines. Profiling blood transcriptomes at 0, 2, 6, and 24 hpi by RNA-sequencing revealed that LPS induced dramatic transcriptional changes, with 6296 genes differentially expressed at at least one time point post injection relative to baseline in at least one line (n = 4 per line) (|log
(fold change)| ≥ log
(1.2); q < 0.05). Furthermore, applying the same cutoffs, we detected 334 genes differentially expressed between the two lines at at least one time point, including 33 genes differentially expressed between the two lines at baseline. But no significant line-by-time interaction effects were detected. Genes involved in protein translation, defense response, immune response, and signaling were enriched in different co-expression clusters of genes responsive to LPS stimulation. The two lines were largely similar in their peripheral blood transcriptomic responses to LPS stimulation at the pathway level, although the low-RFI line had a slightly lower level of inflammatory response than the high-RFI line from 2 to 6 hpi and a slightly higher level of inflammatory response than the high-RFI line at 24 hpi.
The pig lines divergently selected for RFI had a largely similar response to LPS stimulation. However, the low-RFI line had a relatively lower-level, but longer-lasting, inflammatory response compared to the high-RFI line. Our results suggest selection for feed efficient pigs does not significantly compromise a pig's acute systemic inflammatory response to LPS, although slight differences in intensity and duration may occur.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
T cells resident within the intestinal epithelium play a central role in barrier integrity and provide a first line of immune defense. Intraepithelial T cells (IETs) are among the earliest immune ...cells to populate and protect intestinal tissues, thereby giving them an important role in shaping gut health early in life. In pigs, IETs are poorly defined, and their maturation in young pigs has not been well-studied. Given the importance of IETs in contributing to early life and long-term intestinal health through interactions with epithelial cells, the microbiota, and additional environmental factors, a deeper characterization of IETs in pigs is warranted. The objective of this study was to analyze age- and intestinal location-dependent changes in IETs across multiple sites of the small and large intestine in pigs between 4- and 8-weeks of age. IETs increased in abundance over time and belonged to both γδ and αβ T cell lineages. Similar compositions of IETs were identified across intestinal sites in 4-week-old pigs, but compositions diverged between intestinal sites as pigs aged. CD2
CD8α
γδ T cells and CD4
CD8α
αβ T cells comprised >78% of total IETs at all intestinal locations and ages examined. Greater percentages of γδ IETs were present in large intestine compared to small intestine in older pigs. Small intestinal tissues had greater percentages of CD2
CD8α
γδ IETs, while CD2
CD8α
γδ IET percentages were greater in the large intestine. Percentages of CD4
CD8α
αβ IETs increased over time across all intestinal sites. Moreover, percentages of CD27
cells decreased in ileum and large intestine over time, indicating increased IET activation as pigs aged. Percentages of CD27
cells were also higher in small intestine compared to large intestine at later timepoints. Results herein emphasize 4- to 8-weeks of age as a critical window of IET maturation and suggest strong associations between intestinal location and age with IET heterogeneity in pigs.
Abstract A primary swine production goal is to increase efficiency of lean tissue gains. While many swine production systems currently utilize ad libitum feeding, recent research suggests that ...altering feeding patterns may impact feed efficiency. Therefore, the objective of this study was to compare two feeding patterns and evaluate their impact on whole body tissue accretion, feeding behavior and activity in growing pigs. Forty eight individually housed gilts (55.9 ± 5.2 kg on test BW) were assigned into one of two feeding treatments: 1) Free access to the feeder (Free Access) or 2) twice daily access where gilts were allowed to eat ad libitum between 08:00–09:00 h and again from 17:00–18:00 h (2 ×). Pig performance was recorded weekly for 55 days and average daily gain (ADG), average daily feed intake (ADFI), and gain:feed (G:F) was calculated. Body composition was assessed in 12 gilts per treatment using dual X-ray absorptiometry (DXA) at day − 3 and 55 of treatment, and tissue accretion rates were calculated. Gilt behaviors were assessed via video analysis during week 7 and included time spent eating, feeding rate, enrichment interaction, postural changes, standing, sitting, and lying behaviors. Gilts fed 2 × had lower ADG and ADFI compared to Free Access gilts ( P ≤ 0.01); however, no treatment difference in G:F was observed ( P = 0.83). At day 55 gilts fed 2 × had a lower fat:protein compared to Free Access gilts ( P = 0.05). Fat, lean, and protein accretion rates were lower in gilts fed 2 × compared to those fed Free Access ( P = 0.01). Gilts fed 2 × ate less frequently and for a shorter duration of time, interacted with enrichment more frequently ( P ≤ 0.005), and tended to have less frequent postural changes compared to Free Access gilts ( P = 0.08). No treatment differences were observed in duration of time spent standing, sitting, or lying ( P ≥ 0.39). Although feed regimen did not alter feed efficiency, these data indicate that twice daily feeding reduced gilt adiposity and growth without altering the pig's behavioral expression of hunger. Therefore, twice daily feeding may be a method of increasing percent of lean tissue without negatively impacting gilt welfare.
Abstract
An experiment was conducted to determine how feeding calcium (Ca)-deficient diet would affect gastrointestinal pH and volatile fatty acids (VFAs), Ca digestibility, bone mineral density ...(BMD), and performance in nursery pigs; and if supplementation of nondigestible oligosaccharides would affect these same parameters. In total, 240 weaned pigs (BW = 7.1 kg) were placed into 80 pens with 3 pigs/pen. The eight dietary treatments consisted of: 1) positive control (PC, 0.83% total Ca), 2) negative control (NC, 0.50% total Ca), 3 and 4) NC + 5% or 7.5% soluble corn fiber (SCF), 5 and 6) NC + 5% or 7.5% resistant corn starch (rCS), 7 and 8) NC + 0.25% or 0.50% fat-protected butyrate (pBRT). Pigs were ad libitum fed the dietary treatments for 21 d to determine average daily gain (ADG), average daily feed intake (ADFI) and gain:feed ratio (GF) with a fecal sample collected from each pen to determine Ca digestibility using acid insoluble ash as the dietary marker, with 1 pig/pen euthanized on d 21 for collection of ileal and colon contents and the left humerus. Pigs fed the NC diet had a lower colonic pH compared with pigs fed the PC (P = 0.06) but no effect on total VFA was observed (P > 0.10). Pigs fed diets containing SCF and rCS had lower colonic pH and total VFA compared to pigs fed the NC diet (P ≤ 0.05). Pigs fed diets containing pBRT had greater colonic total VFA compared to pigs fed the NC diet (P ≤ 0.07), but no difference in colonic pH was observed (P > 0.10). Pigs fed the NC diet had a greater Ca digestibility compared to pigs fed the PC (P ≤ 0.01), with no treatment to the NC having any effect on Ca digestibility compared to pigs fed the NC (P > 0.10). There was no effect of dietary Ca level on BMD and no overall addition of feeding SCF, rCS, or pBRT on BMD compared to pigs fed the NC (P > 0.10). There was no impact on pig ADG, ADFI, or GF by reducing dietary Ca by 40% (i.e., pigs fed the NC) compared to pigs fed the PC (P > 0.10). Relative to pigs fed the NC, there was no overall effect of SCF, rCS, or pBRT on ADG, ADFI, or GF (P > 0.10). In conclusion, feeding young pigs a Ca-deficient diet reduced colonic pH, increased digestibility of Ca, but had no impact on bone mineralization or overall pig performance. Supplementation of nondigestible oligosaccharides pr protected butyrate had either no effect or an inconsistent effect on colonic pH, Ca, or PHOS digestibility, bone mineralization, or overall pig performance.
Feeding young pigs a diet below recommended levels of calcium (Ca) reduced colonic pH, increased apparent total-tract digestibility of Ca and phosphorus (PHOS), but had no impact on bone mineralization or overall pig performance. Supplementation of nondigestible oligosaccharides had inconsistent effects on colonic pH, and did not affect Ca or PHOS digestibility, bone mineralization, or overall pig performance.
Lay Summary
Calcium (Ca) is a major component of the skeleton in addition to being essential for growth and is imperative for bone mass development. Improvement in Ca absorption in Ca-deficient diets has been shown in human and rodent studies when nondigestible oligosaccharides have been consumed due to a modification of gastrointestinal conditions which increase mineral solubility. Because swine have been shown to be an excellent model for human nutrition research, an experiment was conducted to determine how a moderately Ca-deficient diet would affect gastrointestinal fermentation conditions, Ca and phosphorus (PHOS) digestibility, bone mineralization, and growth performance in nursery pigs; and if supplementation of nondigestible oligosaccharides would affect these same parameters. Results indicate that feeding young pigs a diet below recommended levels of Ca reduced colonic pH, increased apparent total-tract digestibility of Ca and PHOS, but had no impact on bone mineralization or overall pig performance. Supplementation of nondigestible oligosaccharides had inconsistent effects on colonic pH, and did not affect Ca or PHOS digestibility, bone mineralization, or overall pig performance.
This study focused on intestinal restitution including phenotype switching of absorptive enterocytes and the abundance of different enterocyte subtypes in weaned pigs after porcine epidemic diarrhea ...virus (PEDV) infection. At 10 days post-PEDV-inoculation, the ratio of villus height to crypt depth in both jejunum and ileum had restored, and the PEDV antigen was not detectable. However, enterocytes at the villus tips revealed epithelial-mesenchymal transition (EMT) in the jejunum in which E-cadherin expression decreased while expression of N-cadherin, vimentin, and Snail increased. Additionally, there was reduced expression of actin in microvilli and Zonula occludens-1 (ZO-1) in tight junctions. Moreover, the protein concentration of transforming growth factor β1 (TGFβ1), which mediates EMT and cytoskeleton alteration, was increased. We also found a decreased number of Peyer's patch M cells in the ileum. These results reveal incomplete restitution of enterocytes in the jejunum and potentially impaired immune surveillance in the ileum after PEDV infection.
Abstract
Consumption of highly peroxidized oils has been shown to affect pig performance and oxidative status through the development of compounds which differ according to how oils are thermally ...processed. The objective of this study was to evaluate the effect of feeding varying degrees of peroxidized soybean oil (SO) on parameters of growth performance; lipid, N, and GE digestibility, gut integrity in growing pigs, and plasma Trp. Fifty-six barrows (25.3 ± 3.3 kg initial BW) were randomly assigned to one of four diets containing either 10% fresh SO (22.5 °C) or thermally processed SO (45 °C for 288 h, 90 °C for 72 h, or 180 °C for 6 h), each with an air infusion of 15 L/min. Peroxide values for the 22.5, 45, 90, and 180 °C processed SO were 2.0, 96, 145, and 4.0 mEq/kg, respectively; 2,4-decadienal values for 22.5, 45, 90, and 180 °C processed SO were 2.11,5.05, 547.62, and 323.57 mg/kg, respectively; and 4-hydroxynonenal concentrations of 0.05, 1.05, 39.46, and 25.71 mg/kg with increasing SO processing temperature. Pigs were individually housed and fed ad libitum for a 49 d period to determine the effects of SO peroxidation status on growth performance, including a metabolism period for assessing GE and N digestibility, and N retention. In vivo urinary lactulose to mannitol ratio was also assessed to evaluate potential changes in small intestinal integrity. Although there were no differences observed in ADFI (P = 0.19), ADG was decreased in pigs fed 90 °C SO diet (P = 0.01), while G:F was increased (P = 0.02) in pigs fed 45 °C SO diet compared to the other SO diets. Pigs fed the 90 °C processed SO had the lowest (P = 0.01) DE as a percentage of GE, whereas ME as a percentage of DE was lowest (P = 0.05) in pigs fed the 180 °C SO and 90 °C SO followed by 45 °C SO and fresh SO. Ether extract (EE) digestibility was lowest (P = 0.01) in pigs fed 90 °C SO followed by pigs fed 180 °C SO, 45 °C SO, and fresh SO. The percent of N retained was greatest (P = 0.01) in pigs fed fresh SO followed by pigs fed 45 °C SO, 180 °C SO, and 90 °C, respectively. There were no differences observed among SO treatments for urinary lactulose to mannitol ratio (P = 0.60). Pigs fed SO processed at 90 °C and 180 °C had lower concentrations (P < 0.01) of serum Trp compared to pigs fed the 22.5 °C and 45 °C SO treatments. The presence of lipid peroxidation products, namely several aldehydes, contained in the 90 °C SO diet reduced ADG, GE and EE digestibility, and N balance, but had no impact on gut permeability.
Intraepithelial T lymphocytes (T-IELs) are T cells located within the epithelium that provide a critical line of immune defense in the intestinal tract. In pigs, T-IEL abundances and phenotypes are ...used to infer putative T-IEL functions and vary by intestinal location and age, though investigations regarding porcine T-IELs are relatively limited. In this study, we expand on analyses of porcine intestinal T-IELs to include additional phenotypic designations not previously recognized in pigs. We describe non-conventional CD8α+CD8β− αβ T-IELs that were most prevalent in the distal intestinal tract and primarily CD16+CD27−, a phenotype suggestive of innate-like activation and an activated cell state. Additional T-IEL populations included CD8α+CD8β+ αβ, CD2+CD8α+ γδ, and CD2+CD8α− γδ T-IELs, with increasing proportions of CD16+CD27− phenotype in the distal intestine. Thus, putative non-conventional, activated T-IELs were most abundant in the distal intestine within multiple γδ and αβ T-IEL populations. A comparison of T-IEL and respective mucosal microbial community structures across jejunum, ileum, and cecum of 5- and 7-week-old pigs revealed largest community differences were tissue-dependent for both T-IELs and the microbiota. Between 5 and 7 weeks of age, the largest shifts in microbial community compositions occurred in the large intestine, while the largest shifts in T-IEL communities were in the small intestine. Therefore, results indicate different rates of community maturation and stabilization for porcine T-IELs and the mucosal microbiota for proximal versus distal intestinal locations between 5 and 7 weeks of age. Collectively, data emphasize the intestinal tract as a site of location- and age-specific T-IEL and microbial communities that have important implications for understanding intestinal health in pigs.
•Intraepithelial T cell (T-IEL)/microbial communities differ by intestinal location.•Largest age-specific shifts in T-IEL compositions occur in the proximal intestine.•Largest age-specific shifts in microbial compositions occur in the distal intestine.•CD4−CD8α+CD8β− αβ T cells are a non-conventional, innate-like T-IEL subset in pigs.•Non-conventional, activated T-IELs are most abundant in the distal intestine.
is an etiological agent of swine dysentery (SD). Diet fermentability plays a role in development of SD, but the mechanism(s) of action are largely unknown. Thus, this study aimed to determine whether ...replacing lowly fermentable fiber with highly fermentable fiber would mitigate a 42 d
challenge. Thirty-nine barrows were allocated to dietary treatment groups: (1) 20% corn distillers dried grain with solubles (DDGS), 0% beet pulp (BP) or resistant starch (RS; lowly fermentable fiber (LFF)); (2) 10% DDGS, 5% BP, 5% RS (medium fermentable fiber (MFF)); and (3) 0% DDGS, 10% BP, 10% RS (highly fermentable fiber (HFF)). On day post inoculation 0, pigs were inoculated with
. Overall, 85% LFF pigs developed clinical SD, 46% of MFF pigs developed SD, and 15% of HFF pigs developed SD (
< 0.05). Overall average daily gain (ADG) differed among all treatments (
< 0.001), with LFF pigs having the lowest ADG. For HFF pigs, ADG was 37% greater than LFF pigs (
< 0.001) and 19% greater than MFF pigs (
= 0.037). The LFF diet had greater relative abundance of
and
. Further, microbiota of pigs that developed SD had enriched
. Collectively, replacing DDGS with highly fermentable fiber reduced clinical SD, improved performance, and modulated fecal microbiota during
challenge.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract
In swine production, pig movement restrictions or packing plant closures may create the need to slow growth rates of finishing pigs to ensure they remain at a marketable body weight when ...packing plant access is restored. Although dietary formulations can be successful at slowing pig growth, precision is needed regarding how to best formulate diets to achieve growth rate reductions. Thus, the objective was to evaluate three dietary experimental approaches aimed at slowing growth rates in finishing pigs. These approaches consisted of either increasing neutral detergent fiber (NDF), reducing essential amino acids, or reducing the dietary electrolyte balance through the addition of acidogenic salts. A total of 94 mixed-sex pigs (72.4 ± 11.2 kg BW) across two replicates were individually penned and assigned to 1 of 8 dietary treatments (n = 11–12 pigs/treatment): 1) Control diet representative of a typical corn–soybean meal-based finisher diet (CON); 2) diet containing 15% NDF from soybean hulls (15% NDF); 3) diet containing 20% NDF from soybean hulls (20% NDF); 4) diet containing 25% NDF from soybean hulls (25% NDF); 5) diet formulated as per CON but with 50% of the soybean meal replaced with corn (89% Corn); 6) diet containing 97% corn and no soybean meal or synthetic amino acids (97% Corn); 7) diet containing 2% anhydrous calcium chloride (2% CaCl2); and 8) diet containing 4% anhydrous calcium chloride (4% CaCl2). Over 28 d, pig body weights and performance were recorded weekly. At d 28, all pigs were ultrasound scanned and switched to the CON diet to evaluate compensatory gain from d 28 to 35. Overall, increased NDF did not impact any growth performance parameter (P > 0.05). Amino acid restriction reduced average daily gain (ADG), average daily feed intake (ADFI), and gain:feed (G:F) linearly (linear P < 0.001). Similarly, ADG, ADFI, and G:F were linearly reduced with increased CaCl2 inclusion (linear P < 0.001). ADG differed during the compensatory gain period (P < 0.001), with 4% CaCl2-fed pigs having a 47% increase in ADG compared with CON-fed pigs. Conversely, 15% and 25% NDF-fed pigs had reduced ADG compared with CON-fed pigs during the compensatory gain period. Gain efficiency differed from day 28 to 35 (P < 0.001), with 4% CaCl2-fed pigs having a 36% increase in G:F compared with CON-fed pigs. Altogether, these data demonstrate that both amino acid restriction and CaCl2 inclusion are effective at slowing pig growth, albeit at greater inclusion rates.
Abstract
Optimal lean tissue production can be severely compromised by health challenges in nursery-finisher pig production systems. Common pig immune challenges in the U.S. can come from pathogens ...such as Porcine Reproductive and Respiratory Syndrome virus, Lawsonia intracellularis, Mycoplasma spp, Coccidia, pathogenic E. coli and Porcine Epidemic Diarrhea virus. The subsequent disease that can manifests in response to these pathogens can lead to mitochondrial damage, impaired capacity to generate sufficient ATP for homeostasis, limited energy availability (exacerbated by disease hypophagia) and compromised cell survival and organ function. Collectively, skeletal muscle hypertrophy is reduced in a trade off to support the energetic and protein synthesis needs of immune system response. In growing pigs, we have reported that sub-clinical and clinical enteric and respiratory disease can significantly impact intestinal function, feed intake, lean tissue accretion and feed efficiency. This has a major economic impact for pork producers, pig welfare and wellbeing. While significant advances in molecular and quantitative genetics, clinical diagnostics and virology have been made to enhance poor performance and heath, we are still unsure on how to best feed and manage poor-health pigs. By understanding the longitudinal impact pathogens on digestibility, metabolism, protein accretion and feed efficiency, insights into nutritional requirements and management strategies can be developed to improve poor-health pig production. This paper will discuss the molecular and physiological impact of sub-clinical and clinical disease on nutrient and energy intake and utilization to support lean tissue accretion in growing pigs.
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