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Antibiotics have traditionally been used for growth promotion in the pork industry; however, their use in animal feed has recently been limited because of human health concerns. The intestinal microbiota plays an important role in mediating many physiological functions such as digestion and animal growth. It was hypothesized that use of antibiotics as growth promotants and subsequent variations in intestinal microbiota induce significant changes in the intestinal glycoconjugate composition, which ultimately affects animal growth and disease susceptibility. The aim of this study was to characterize the lectin binding profiles of the ileum of weanling pigs in response to the absence of intestinal microbiota and to the use of the antibiotic chlortetracycline as growth promotant. Eighteen half-sib piglets obtained by cesarean section were divided into 3 treatment groups (n = 6) and maintained as control, antibiotic-fed, and gnotobiotic piglets until 5 wk of age. The glycoconjugate composition of the ileal tissues was examined by lectin histochemistry. Lycopersicon esculentum lectin, Jacalin, Pisum sativum agglutinin, Lens culinaris agglutinin (LCA), and Sambucus nigra lectin showed significant differences (P < 0.05) in binding intensities on the dome and villous epithelium between the treatment groups. Griffonia simplicifolia lectin I, Glycine maxi agglutinin, and Arachis bypogea agglutinin exhibited differences (P < 0.05) between treatment groups in lectin binding on goblet cells. Triticum vulgaris agglutinin, Pisum sativum agglutinin, and LCA showed significant differences (P < 0.05) in binding intensities on dome, corona, and follicular regions of the ileum among treatment groups of animals. Overall, ileal tissues from gnotobiotic piglets expressed significantly weaker (P < 0.05) lectin binding for many lectins compared with control and antibiotic groups. This suggests that the intestinal microbiota plays an important role in the expression of sugar moieties in the intestine. Lectins LCA, Phaseolus vulgaris Leucoagglutinin, and Maackia amurensis lectin II showed significant differences (P < 0.05) in lectin bindings between control and antibiotic-fed piglets. This indicates that chlortetracycline as a growth promotant induces biologically relevant changes in the lectin binding profile of the ileum. These findings will help in further understanding the role of the gut microbiota and the mechanisms of action of antibiotics as growth promotants in pigs. Key words: chlortetracycline, gnotobiotic, growth promotant, intestinal microbiota, lectin, pig

The objectives of this experiment were to evaluate the effect of oil source and peroxidation status on broiler performance and oxidative stress. Broilers (initial BW 85.1 ± 7.8 g) were allotted to 40 cages with 5 birds per cage in a completely randomized design. The 4 × 2 factorial arrangement of treatments consisted of oil source (palm oil, soybean oil, flaxseed oil, and fish oil) and peroxidation status (fresh or peroxidized). Broilers were fed experimental diets for 20 d to measure growth performance; on day 21 of the experiment, plasma and liver samples were harvested for analysis of oxidative stress including thiobarbituric acid reactive substances (TBARS), protein carbonyls (PC), 8-hydroxy-2'-deoxyguanosine (8- OH-2dG), glutathione peroxidase activity (GPx) and superoxide dismutase and catalase (CAT). An interaction occurred between oil source and peroxidation status where broilers fed peroxidized oils had reduced ADFI, ADG, G:F, and plasma GPx in all oil sources except for fish oil (P ≤ 0.04). Plasma 8-OH-2dG was increased by feeding peroxidized oils (P = 0.01). An interaction occurred in liver TBARS where broilers fed peroxidized palm oil had greater liver TBARS compared to fresh palm oil (P = 0.09). An interaction was noted for liver PC where broilers fed palm, flaxseed, and fish oil had similar liver PC regardless of peroxidation status, while broilers fed peroxidized soybean oil had increased liver PC compared to the fresh soybean oil diet (P = 0.04). Oil source affected plasma TBARS and 8-OH-2dG (P = 0.01), plasma PC (P = 0.09), liver 8-OH-2dG (P = 0.08), and liver CAT (P = 0.02). Correlations between oil composition with growth performance and oxidative stress markers imply that oil UFA:SFA, p-anisidine value, DDE, total polar compounds, and polymerized triglycerides should be measured as an indicator of oil quality, with growth performance being correlated to plasma TBARS, PC, and GPx. In conclusion, the degree of unsaturation and peroxidation status of dietary oils affected growth performance and markers of oxidative stress in poultry. [ABSTRACT FROM AUTHOR]

The objectives of this study were to determine whether feeding thermally processed peroxidized soybean oil (SO) induces markers of oxidative stress and alters antioxidant status in pig tissue, blood, and urine. Fifty-six barrows (25.3 ± 3.3 kg initial BW) were randomly assigned to dietary treatments containing 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 constant air infusion rate of 15 liters/minute. Multiple indices of lipid peroxidation were measured in the SO including peroxide value (2.0, 96, 145, and 4.0 mEq/kg for 22.5, 45, 90, and 180 °C processed SO, respectively) and p-anisidine value (1.2, 8.4, 261, and 174 for 22.5, 45, 90, and 180 °C processed SO, respectively); along with a multitude of aldehydes. Pigs were individually housed and fed ad libitum for 49 d which included a 5 d period in metabolism crates for the collection of urine and serum for measures of oxidative stress. On day 49, pigs were euthanized to determine liver weight and analyze liver-based oxidative stress markers. Oxidative stress markers included serum, urinary, and liver thiobarbituric acid reactive substances (TBARS), and urinary F2-isoprostanes (ISP) as markers of lipid damage; serum and liver protein carbonyls (PC) as a marker of protein damage; and urinary and liver 8-hydroxy-2'-deoxyguanosine (8-OH-2dG) as a marker of DNA damage. Superoxide dismutase (SOD), and catalase activity (CAT) were measured in liver, glutathione peroxidase activity (GPx) was measured in serum and liver, and ferric reducing antioxidant power (FRAP) was measured in serum and urine as determinants of antioxidant status. Pigs fed 90 °C SO had greater urinary ISP (P = 0.02), while pigs fed the 45 °C SO had elevated urinary TBARS (P = 0.02) in comparison to other treatment groups. Pigs fed 45 °C and 90 °C SO had increased serum PC concentrations (P = 0.01) and pigs fed 90 °C SO had greater (P = 0.01) liver concentration of 8-OH-2dG compared to pigs fed the other SO treatments. Furthermore, pigs fed 90 °C SO had reduced serum GPx activity in comparison to pigs fed fresh SO (P = 0.01). In addition, pigs fed 180 °C SO had increased liver CAT activity (P = 0.01). Liver GPx and SOD or serum and urinary FRAP were not affected by dietary treatment. These results indicate that dietary peroxidized soybean oil induced oxidative stress by increasing serum PC while diminishing serum GPx, increasing urinary ISP and TBARS, and increasing 8-OH-2dG and CAT in liver. [ABSTRACT FROM AUTHOR]

An experiment was conducted to evaluate the impact of lipid source on GE and ether extract (EE) digestibility, oxidative stress, and gut integrity in nursery pigs fed diets containing 10% soybean oil (SO), choice white grease (CWG), palm oil (PO), distillers' corn oil with approximately 5% FFA (DCO-1), or distillers' corn oil with approximately 10% FFA (DCO-2). Fifty-four barrows weaned at 28 d of age were fed a common starter diet for 7 d, group fed their respective experimental diets for an additional 7 d, and then moved to metabolism crates and individually fed their respective diets for another 10 d. Following this period, a 4-d total fecal and urine collection period was used to determine apparent total tract digestibility (ATTD) of GE and EE and to determine the DE and ME content of each lipid source (11.03 ± 0.51 kg final BW). Following the last day of fecal and urine collection, pigs were given an oral dose of lactulose and mannitol and fed their respective experimental diets with urine collected for the following 12 h. A subsequent urine collection occurred for 5 h to determine thiobarbituric acid reactive substances (TBARS) and isoprostane (IsoP) concentrations. Following this urine collection, serum was obtained and analyzed for TBARS and endotoxin concentrations. Soybean oil had the greatest (P < 0.05) DE (9,388 kcal/kg) content compared with DCO-1, DCO-2, CWG, and PO (8,001, 8,052, 8,531, and 8,293 kcal/kg lipid, respectively). Energy digestibility was greatest for SO compared with the other lipid sources (P < 0.05). The ATTD of EE averaged 85.0% and varied slightly (84.4 to 85.6%) among treatments. Differences in ME content among lipids were similar to those reported for DE, with ME values for DCO- 1, DCO-2, CWG, PO, and SO being 7,921, 7,955, 8,535, 8,350, and 9,408 kcal/kg lipid, respectively. Metabolizable energy as a percentage of DE did not differ among lipid sources. Pigs fed lipid diets had greater (P < 0.05) serum TBARS compared with pigs fed the control diet, but no differences were observed in urinary TBARS excretion among the lipid treatments. Urinary IsoP excretion differed among treatments (P < 0.01) but was highly variable (34.0 to 104.6 pg). However, no differences were observed among treatments for the urinary lactulose:mannitol ratio and serum endotoxin. These results indicate that DE and ME content of SO are greater than that of other lipid sources evaluated, but feeding these lipids has no effect on gut integrity while producing variable effects on oxidative stress. [ABSTRACT FROM AUTHOR]

In this paper we describe carbon-rich filamentous structures observed in association with the zeolite mineral phillipsite from sub-seafloor samples drilled and collected during the Ocean Drilling Program (ODP) Leg 197 at the Emperor Seamounts. The filamentous structures are ~5 µm thick and ~100–200 µm in length. They are found attached to phillipsite surfaces in veins and entombed in vein-filling carbonates. The carbon content of the filaments ranges between ~10 wt% C and 55 wt% C. They further bind to propidium iodide (PI), which is a dye that binds to damaged cell membranes and remnants of DNA. Carbon-rich globular microstructures, 1–2 µm in diameter, are also found associated with the phillipsite surfaces as well as within wedge-shaped cavities in phillipsite assemblages. The globules have a carbon content that range between ~5 wt% C and 55 wt% C and they bind to PI. Ordinary globular iron oxides found throughout the samples differ in that they contain no carbon and do not bind to the dye PI. The carbon-rich globules are mostly concentrated to a film-like structure that is attached to the phillipsite surfaces. This film has a carbon content that ranges between ~25 wt% C and 75 wt% C and partially binds to PI. EDS analyses show that the carbon in all structures described are not associated with calcium and therefore not bound in carbonates. The carbon content and the binding to PI may indicate that the filamentous structures could represent fossilized filamentous microorganisms, the globules could represent fossilized microbial cells and the film-like structures could represent a microbially produced biofilm. Our results extend the knowledge of possible habitable niches for a deep biosphere in sub-seafloor environments and suggests, as phillipsite is one of the most common zeolite mineral in volcanic rocks of the oceanic crust, that it could be a common feature in the oceanic crust elsewhere. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine possible interactions between serotonergic and dopaminergic agents lowering core temperature via stimulation of 5-HT1A and dopamine (DA) D2 receptors, respectively. The effects of the 5-HT1A receptor agonist (±)-8-hydroxy-2-(di-n-propylamino)tetralin HBr (8-OH-DPAT) and the DA D2/3 receptor agonist 7-OH-DPAT on core temperature was monitored in adult male Wistar rats, approximately 300 g body weight. The temperature probe was connected to a PC-assisted temperature instrument, and an automated printer device was activated when the temperature reading had stabilized (±0.1 °C) for 10 s. As expected, 7-OH-DPAT [0.5 and 2.0 μmol kg–1 subcutaneous (s.c.)] as well as 8-OH-DPAT (0.15–2.4 μmol kg–1 s.c.), produced a dose-dependent hypothermia. When combined, there were additive effects of the two compounds, although the effects of 7-OH-DPAT were attenuated by 8-OH-DPAT at the higher doses (0.6–2.4 μmol kg–1), in all probability because of emerging DA D2 receptor blocking properties of the latter compound. [ABSTRACT FROM AUTHOR]

Optimal nutrient utilization by farm animals is essential for supporting growth and development and is vital in maintaining economical animal production. While profiles, digestibilities, and balances of energy and nutrients of feedstuffs are critical in the nutrient utilization matrix, so is the ability of the animal to balance mechanisms generating oxidative stress with antioxidant defenses within the body. Pro-oxidants can be of environmental, dietary, or metabolic origin, where oxidative stress occurs when free radical production overwhelms the antioxidant defense system. While it is well known that free radicals can bind to or damage proteins, lipids, and DNA, most research to date involving oxidative stress in farm animals has focused on relatively few measures of oxidative stress (e.g., thiobarbituric acid reactive substances) or antioxidant status (e.g., Vitamin E or glutathione peroxidase); often only in one select tissue. Furthermore, traditional metabolite analysis in nutrition studies are hypothesis-driven and are generally designed to study a specific measure for a specific target, which may be limiting our ability to identify potentially novel and unexpected metabolic activities, especially in complex metabolic events and pathways associated with metabolism. It is hypothesized, therefore, that in order to accurately determine oxidative balance of the whole animal, multiple measures of lipid, protein, or DNA damage should be measured in combination with multiple measures of antioxidant capacity. In addition, a more comprehensive and non-targeted approach in experimental design and data analysis is likewise suggested in order to obtain a broader view of metabolic events (e.g., metabolomics, neuro networks, or multivariate analysis) in response to environmental, dietary, or metabolic stressors. While a proportion of this presentation will discuss recent research using peroxidized lipids as an inducer of oxidative stress and key measures of oxidative stress measured in multiple tissues, additional information will be provided on other models to generate oxidative stress (e.g., heat stress, disease, chemical injections, mycotoxins) in an effort to delineate if different stressors cause differential oxidative stress responses requiring stress- or tissue-specific measures, or can whole animal oxidative stress be measured using the same oxidative balance measures. [ABSTRACT FROM AUTHOR]

An experiment was conducted to evaluate the impact of lipid source on energy and lipid digestibility, and on metabolic oxidation status of nursery pigs fed diets containing 10% of soybean oil (SO), choice white grease (CWG), palm oil (PO), or 1 of 2 different sources of distillers corn oil (DCOl and DCO2). Fifty-four barrows weaned at 28-d of age were fed a common starter diet from d 1 to 7, followed by group feeding their respective experimental diets (either 100% basal or 90% basal + 10% test lipid) from d 8 to 14 to adapt the pigs to their dietary treatments and to optimize subsequent feed intake. For the next 10 d (d 15 to 24), pigs were moved to metabolism crates for continued diet adaptation and to become accustomed to the twice daily feeding regimen in the metabolism crates. Following this period, a 4-d total fecal and urine collection occurred (d 25 to 29, final BW 11.03 ± 0.51 kg) to determine apparent total tract digestibility (ATTD) of energy and lipids, and to determine the DE and ME content of each lipid source. After an overnight fast of 12 h, urine was collected for 5 h, quantified, and subsequently analyzed for thiobarbituric acid reactive substances (TBARS) and isoprostane (IsoP) concentration. Following this collection, serum was obtained and analyzed for TBARS. Soybean oil had greatest (P < 0.05) DE (9388 kcal/kg) content compared with DCOl, DCO2, CWG, PO, and SO containing 8001, 8052, 8531, 8293, and 9388 kcal/kg lipid, respectively. Digestible energy as a percentage of GE was greatest (P < 0.05) for SO when compared to the other lipid sources (P < 0.05). The ATTD of EE averaged 85.0% and varied slightly (84.4% to 85.6%) among treatments. Differences in ME among lipids were similar to that for DE, with ME values for DCOl, DCO2, CWG, PO, and SO containing 7921, 7955, 8535, 8350, and 9408 kcal/kg lipid, respectively. Metabolizable energy as a percentage of DE did not differ between lipid sources. Pigs fed the diets containing lipids had higher (P < 0.05) plasma TBARS compared to pigs fed the control diet, but no differences were noted in urinary TBARS excretion among treatments. Urinary IsoP excretion differed among treatments (P < 0.01), but was highly variable (34.0 to 104.6 pg/ml). These results indicate that DE and ME values vary among lipid sources and appear to have variable effects on metabolic oxidation measures. [ABSTRACT FROM AUTHOR]

Twenty-nine Angus yearling steers (BW=417.3 ±31.3 kg) were used in a 2X2 factorial experiment conducted over 105 d feeding period to determine the effects of Synovex-S and ractopamine on serum concentration of IGF-I, performance and carcass characteristics. Traits analyzed were ADG from 0 d to 105 d after implant (ADG1) and ADG from 70 d to 105 d (ADG2), after starting ractopamine administration, HCW, LM area (LMA), back fat thickness (BF), marbling score (MARB), KPH and Yield Grade (YG), IGF-I and estradiol-17β (E2) concentrations. Treatments included: 1) control (C), 2) ractopamine (R), 3) Synovex-S implant (I) and 4) ractopamine and implant (RI). Weights were collected monthly, while blood samples were drawn on 0, 7, 35, 79 and 105 d. No interactions were found for any trait analyzed. ADG1 were 1.42, 1.55, 1.70 and 1.72 kg/d while ADG2 were 1.43, 1.73, 1.67 and 1.81 kg/d for C, R, I and RI respectively. Synovex-S affected ADG1 (P=0.02) but did not affect ADG2 (P=0.17). Ractopamine tended to increase ADG2 (P=0.06). No significant differences were found for HCW, LMA, BF, MARB, KPH or YG. Average carcass traits were HCW=357.8kg, LMA=83.1cm2, BF=1.12cm, MARB=415 (SM15), KPH=1.93% and YG=2.87. Synovex-S increased mean serum concentrations of E2 by 44% at 7 d (P=0.0003), by 42% at 35 d (P=0.0001), by 46% at 79 d (P=0.0001) and 13% at 105 d (P=0.012). Synovex-S increased mean serum concentrations of IGF-I by 43% at 7 d (P=0.036), by 51% at 5 d (P=0.007), by 60% at 79 d (P=0.011) and 25% at 105 d (P=0.063). Ractopamine did not alter serum concentration of E2 or IGF-I. Results indicate an effect of Synovex-S on IGF-I concentrations as well as on ADG1. Reduced increase on E2 and IGF-I might explain the lack of significance on ADG2 from the implant. Gene expression analysis using microarray will be performed on mRNA extracted from muscle biopsies (79 d) to identify changes in response to ractopamine and Synovex-S. [ABSTRACT FROM AUTHOR]