Neopterin and biopterin as biomarkers of immune system activation associated with castration in piglets

Posted in: Production by admin on August 5, 2011 | No Comments

Recent reports have shown that stressful situations may affect the production of unconjugated pterins (neopterin and biopterin). The aim of the study was to investigate the effect of castration on neopterin and biopterin plasma concentrations in piglets, using 2 groups of 12 piglets allocated to castrated and uncastrated (control) groups. Pterin concentrations were determined by HPLC with fluorescence detection. Blood samples were also analzyed for leukocyte profiles and plasma cortisol concentrations. A time × treatment interaction was detected for neopterin concentrations, such that neopterin was greater at 1 h after surgery in castrated piglets compared with precastration concentrations, and neopterin was greater in castrated than in control piglets at 1 h. Castration had no effect on biopterin concentration. Time effects for neutrophil and lymphocyte concentrations and neutrophil-to-lymphocyte ratios were found. A time × treatment interaction was detected for plasma cortisol concentrations, such that cortisol was greater at 1 and 24 h after surgery in castrated piglets compared with precastration concentrations and was greater in castrated than in control piglets at 1 and 24 h. This study showed that castration activated the immune system of piglets as demonstrated by an increase in plasma neopterin concentrations.

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Effect of dietary organic microminerals on starter pig performance, tissue mineral concentrations, and liver and plasma enzyme activities

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Weanling pigs (n = 160) were used to evaluate dietary essential microminerals (Cu, Fe, Mn, Se, and Zn) on performance, tissue minerals, and liver and plasma enzymatic activities during a 35-d postweaning period. A randomized complete block design with 5 treatments and 8 replicates was used in this study. Organic microminerals were added to complex nursery diets at 0 (basal), 50, 100, or 150% of the requirements of microminerals listed by the 1998 NRC. A fifth treatment contained inorganic microminerals at 100% NRC and served as the positive control. Pigs were bled at intervals with hemoglobin (Hb), hematocrit (Hct), glutathione peroxidase, and ceruloplasmin activities determined. Six pigs at weaning and 1 pig per pen at d 35 were killed, and the liver, heart, loin, kidney, pancreas, and the frontal lobe of the brain were collected for micromineral analysis. The liver was frozen in liquid N for determination of enzymatic activities. The analyzed innate microminerals in the basal diet met the NRC requirement for Cu and Mn but not Fe, Se, and Zn. Performance was not affected from 0 to 10 d postweaning, but when microminerals were added to diets, ADG, ADFI, and G:F improved from 10 to 35 d and for the overall 35-d period. Pigs fed the basal diet exhibited parakeratosis-like skin lesions, whereas those fed the supplemental microminerals did not. This skin condition was corrected after a diet with the added microminerals was fed. When the basal diet was fed, Hb and Hct declined, but supplemental microminerals increased Hb and Hct values. Liver catalase activity increased when microminerals were fed. The Mn superoxide dismutase activity tended to decline quadratically when supplemental microminerals were fed above that of the basal diet. Liver plasma glutathione peroxidase activities were greater when dietary organic and inorganic micromineral were fed. Liver concentrations of microminerals increased linearly as dietary microminerals increased, indicating that the liver was the primary storage organ. Micromineral tissue concentrations were least in pigs fed the basal diet and increased (quadratic) to the 50% level of organic microminerals in the various tissues collected. The results indicated that innate microminerals, Cu and Mn, from a complex nursery diet may meet the micromineral needs of the weaned pig, but the need for Fe, Se, or Zn was not met by the basal diet.

Bioavailability of dietary cyanocobalamin (vitamin B12) in growing pigs

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The present project aimed to estimate bioavailability of dietary vitamin B12, for which little information is available in growing pigs. Two approaches, each using 2 quantities of dietary cyanocobalamin, were compared; the first was based on whole body retention for 8 d and the second was based on nycthemeral portal net flux of vitamin B12. In the first trial, 15 blocks of 3 pigs (31.7 kg of BW) were formed according to their vitamin B12 status. Within each block, 1 pig (CONT) was killed and tissues were sampled for vitamin B12 determination. The remaining 2 piglets were fed 25 (B12-25) or 250 (B12-250) μg daily of cyanocobalamin for 8 d. Urine was sampled twice daily, and the pigs were killed and sampled as CONT pigs. The total content of vitamin B12 in the carcass, urine, and intestinal tract was affected by the dietary treatments but not in the liver. The whole body retention of vitamin B12 was greater in B12-250 than B12-25 pigs, but the corresponding bioavailability was estimated to be 5.3 and 38.2%, respectively. In trial 2, 11 pigs (35.1kg of BW and 75.4 d of age) fed a diet unsupplemented with vitamin B12 from weaning at 28 d of age were surgically equipped with catheters in the portal vein and carotid artery and an ultrasonic flow probe around the portal vein. Each pig received 3 boluses of 0 (B12-0), 25, and 250 μg of dietary vitamin B12 according to a crossover design. Postprandial nycthemeral arterial plasma concentrations of vitamin B12 reached minimum values between 15 and 18 h postmeal that were 29.6, 15.6, and 10.0% less than the premeal values for B12-0, B12-25, and B12-250 pigs, respectively (linear). The cumulative net flux of vitamin B12 for 24 h corresponded to 2.4 and 5.1 μg for B12-25 and B12-250 treatments, respectively, and the corresponding bioavailability was estimated to be 9.7 and 2.0%, respectively. Although bioavailability estimates varied according to approaches, both showed the inverse relationship between dietary vitamin B12 and bioavailability of the vitamin. The dietary supplement of 25 μg was sufficient to maximize hepatic vitamin B12 retention and to attenuate the nycthemeral decrease of arterial plasma concentration of the vitamin.

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Metabolizable energy content of refined glycerin and its effects on growth performance and carcass and pork quality characteristics of finishing pigs

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Two studies were conducted with refined glycerin (97.7 and 97.5% glycerin for studies I and II, respectively) to determine ME content and effects on growth performance and carcass and pork quality measures of finishing pigs. An energy balance study using 24 barrows (21.5kg initial BW) determined the apparent ME content of glycerin using a generalized randomized block design with 2 dietary treatments: 1) control (99.85% corn + vitamins and minerals) and 2) glycerin (30% of corn in the control diet replaced with glycerin). A 7-d adaptation was followed by a 5-d collection period for feces and urine. The energy content of diets, feces, and urine was determined by bomb calorimetry. The DE of the glycerin diet was greater than that of the control diet (4,298 vs. 3,902 kcal/kg of DM); however, the ME content of the 2 diets was similar (3,820 vs. 3,723 kcal/kg of DM). The ME of refined glycerin (estimated by difference) was 3,584 kcal/ kg of DM. A growth study was conducted with 128 gilts housed in groups of 4 and reared from 92.5 kg of BW for a 28-d period, using a split-plot design with a 4 × 2 factorial arrangement of treatments: 1) dietary glycerin level (0, 5, 10, and 15%) and 2) preslaughter handling (gentle vs. intense). The handling treatment was included to simulate the range in handling intensities that are likely to be experienced in practice. At the end of the 28-d period, one-half of the pens on study were slaughtered and used for carcass and pork quality evaluation with 2 pigs from each pen being subjected to each of the preslaughter handling treatments. There were no interactions between dietary glycerin and preslaughter handling treatment. Dietary glycerin had no effect on growth performance, carcass measures, or meat quality. There were no differences between the gentle and intense handling treatments for carcass or pork quality measures. In conclusion, feeding glycerin to finishing pigs at up to 15% of the diet had no negative effect on growth performance or carcass and pork quality characteristics.

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Additivity of effects from dietary copper and zinc on growth performance and fecal microbiota of pigs after weaning

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Four experiments were conducted todetermine the interactive effects of pharmacologicalamounts of Zn from ZnO and Cu from organic (Cu-AA complex; Cu-AA) or inorganic (CuSO4) sources ongrowth performance of weanling pigs. The Cu was fedfor 4 (Exp. 1) or 6 (Exp. 2, 3, and 4) wk after weaning,and Zn was fed for 4 (Exp. 1) or 2 (Exp. 2, 3, and 4) wkafter weaning. Treatments were replicated with 7 pensof 5 or 6 pigs per pen (19.0 d of age and 5.8 kg of BW, Exp. 1), 12 pens of 21 pigs per pen (about 21 d of age and 5.3 kg of BW, Exp. 2), 5 pens of 4 pigs per pen (20.3 d of age and 7.0 kg of BW, Exp. 3), and 16 pens of 21 pigs per pen (about 21 d of age and 5.7 kg of BW, Exp. 4). In Exp. 1 and 2, Cu-AA (0 vs. 100 mg/kg of Cu) and ZnO (0 vs. 3,000 mg/kg of Zn) were used in a 2 × 2 factorial arrangement. Only Exp. 1 used in-feed antibiotic (165 mg of oxytetracycline and 116 mg of neomycin per kilogram feed), and Exp. 2 was conducted at a commercial farm. In Exp. 3, sources of Cu (none; CuSO4 at 250 mg/kg of Cu; and Cu-AA at 100 mg/kg of Cu) and ZnO (0 vs. 3,000 mg/ kg of Zn) were used in a 3 × 2 factorial arrangement. In Exp. 4, treatments were no additional Cu, CuSO4 at 315 mg/kg of Cu, or Cu-AA at 100 mg/kg of Cu to a diet supplemented with 3,000 mg/kg of Zn from ZnO and in-feed antibiotic (55 mg of carbadox per kilogram of feed). In Exp. 1 and 2, both Zn and Cu-AA improved ADG and ADFI. No interactions were observed, except in wk 1 of Exp. 2, where Zn increased the G:F only in the absence of Cu-AA (Cu- AA × Zn). A naturally occurring colibacillosis diarrhea outbreak occurred during this experiment. The ZnO addition reduced the number of pigs removed and pig-days on antibiotic therapy. In Exp 3, ADFI in wk 2 was improved by Zn and Cu with no interactions. In wk 1, G:F was reduced by ZnO only in the absence of Cu (Cu × Zn). Feeding Zn decreased fecal microbiota diversity in the presence of CuSO4 but increased it in the presence of Cu-AA (Cu source × Zn). In Exp. 4, Cu supplementation improved the overall ADG and G:F. The CuSO4 effect on G:F was greater than the Cu-AA effect. Our results indicate that pharmacological amounts of ZnO and Cu (Cu-AA or CuSO4) are additive in promoting growth of pigs after weaning.

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Relative bioavailability of phosphorus in inorganic phosphorus sources fed to growing pigs

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The relative bioavailability of P in 5 sources of inorganic P was determined using growing pigs. The 5 sources of inorganic P were dicalcium phosphate (DCP), monocalcium phosphate (MCP) containing 50% MCP (MCP50), MCP containing 70% MCP (MCP70), MCP containing 100% MCP (MCP100), and monosodium phosphate (MSP). A total of 11 diets were formulated. The basal diet was formulated to contain 0.10% P, and 10 additional diets were formulated by adding 0.07 or 0.14% P from each of the 5 P sources to the basal diet. Growing pigs (n = 44; initial BW: 16.8 kg) were individually housed and randomly allotted to the 11 experimental diets. Feed was provided on an ad libitum basis throughout the 28-d experimental period. At the conclusion of the experiment, all pigs were killed, and 4 bones (i.e., the third and fourth metacarpals on both front feet) were harvested. Bone-breaking strength, bone ash, and Ca and P concentrations were determined. The concentration of bone ash increased as MCP50, MCP70, MCP100, or MSP were added to the basal diet, and the concentration of bone P also increased as MCP70, MCP100, or MSP were added to the basal diet. The relative bioavailability of P in each of the feed phosphates was determined using slope ratio methodologies based on breaking strength, and expressed relative to MSP. The slope of the regression line for diets containing MSP or MCP100 was steeper than the slope for pigs fed the diet containing DCP, but not different from that of pigs fed diets supplemented with MCP50 or MCP70. In conclusion, P in MSP and MCP100 is more bioavailable than P in DCP, but there were no differences within MCP sources.

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Use of Saccharomyces cerevisiae fermentation product on growth performance and microbiota of weaned pigs during Salmonella infection

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Anaerobically fermented yeast products are a rich source of nutritional metabolites, mannanoligosaccharides, and β-glucans that may optimize gut health and immunity, which can translate into better growth performance and a reduced risk of foodborne pathogens. The objective of this study was to quantify the effects of Saccharomyces cerevisiae fermentation product (Diamond V Original XPC) inclusion in nursery diets on pig performance and gastrointestinal microbial ecology before, during, and after an oral challenge with Salmonella. Pigs (n = 40) were weaned at 21 d of age, blocked by BW, and assigned in a 2 × 2 factorial arrangement consisting of diet (control or 0.2% XPC) and inoculation (sterile broth or Salmonella). Pigs were fed a 3-phase nursery diet (0 to 7 d, 7 to 21 d, and 21 to 35 d) with ad libitum access to water and feed. On d 14, pigs were orally inoculated with 109 cfu of Salmonellaenterica serovar Typhimurium DT104 or sterile broth. During d 17 to 20, all pigs were treated with a 5 mg/kg of BW intramuscular injection of ceftiofur-HCl. Growth performance and alterations in the gastrointestinal microbial ecology were measured during preinoculation (PRE; 0 to 14 d), sick (SCK; 14 to 21 d), and postinoculation (POST; 21 to 35 d). Body weight and ADG were measured weekly. Rectal temperature (RT) was measured weekly during PRE and POST, and every 12 h during SCK. Diet had no effect on BW, ADG, or RT during any period. Inclusion of XPC tended to increase Salmonella shedding in feces during SCK. Consumption of XPC altered the composition of the gastrointestinal microbial community, resulting in increased populations of Bacteroidetes and Lactobacillus after Salmonella infection. Pigs inoculated with Salmonella had decreased ADG and BW, and increased RT during SCK. Furthermore, fecal Salmonella cfu (log10) was modestly correlated with BW (r = −0.22), ADFI (r = −0.27), ADG (r = −0.36), G:F (r = −0.18), and RT (r = 0.52) during SCK. After antibiotic administration, all Salmonella-infected pigs stopped shedding. During POST, an interaction between diet and inoculation on ADG indicated that pigs infected with Salmonella grew better when eating XPC than the control diet. The addition of XPC to the diets of weanling pigs resulted in greater compensatory BW gains after infection with Salmonella than in pigs fed conventional nursery diets. This increase in BW gain is likely associated with an increase in beneficial bacteria within the gastrointestinal tract.

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Limited and excess dietary protein during gestation affects growth and compositional traits in gilts and impairs offspring fetal growth

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The aim of this study was to investigate whether dietary protein intake during gestation less than or greater than recommendations affects gilts growth and body composition, gestation outcome, and colostrum composition. German Landrace gilts were fed gestation diets (13.7 MJ of ME/kg) containing a low (n = 18; LP, 6.5% CP), an adequate (n = 20; AP, 12.1%), or a high (n = 16; HP, 30%) protein content corresponding to a protein: carbohydrate ratio of 1:10.4, 1:5, and 1:1.3, respectively, from mating until farrowing. Gilts were inseminated by semen of pure German Landrace boars and induced to farrow at 114 d postcoitum (dpc; Exp. 1). Energy and protein intake during gestation were 33.3, 34.4, and 35.8 MJ of ME/d and 160, 328, and 768 g/d, respectively, in LP, AP, and HP gilts. From insemination to 109 dpc, BW gain was least in LP (42.1 kg), intermediate in HP (63.1 kg), and greatest in AP gilts (68.3 kg), whereas increase of backfat thickness was least in gilts fed the HP diet compared with LP and AP diets (3.8, 5.1, 5.0 mm). Litter size, % stillborn piglets, and mummies were unaffected by the gestation diet. Total litter weight tended to be less in the offspring of LP and HP gilts (14.67, 13.77 vs. 15.96 kg), and the percentage of male piglets was greater in litters of HP gilts (59.4%). In piglets originating from LP and HP gilts, individual birth weight was less (1.20, 1.21 vs. 1.40 kg) and birth weight/crown-rump length ratio was reduced (45.3, 46.4 vs. 50.7 g/cm). Colostrum fat (7.8, 7.4 vs. 8.1%) and lactose concentrations (2.2, 2.1 vs. 2.6%) tended to be reduced in LP and HP gilts. In Exp. 2, 28 gilts (LP, 10; AP, 9; HP, 9) were treated as in Exp. 1 but slaughtered at 64 dpc. At 64 dpc, LP gilts were 7% lighter than AP gilts, whereas HP gilts were similar to AP gilts. Body composition was markedly altered in response to LP and HP feeding with less lean and greater fat content in LP and less fat content in HP gilts. Fetal litter weight and number, and embryonic survival at 64 dpc were not affected by the diets. These results indicated that gestation diets containing protein at 50 and 250% of recommendations and differing in protein: carbohydrate ratio led to marked changes in protein and fat metabolism in gilts resulting in fetal growth retardation of 15%, which mainly occurred during the second half of gestation.

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Breed difference and regulation of the porcine Sirtuin 1 by insulin

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Sirtuin 1 (Sirt1) plays an important role in fat metabolism. In the current study, we examined the breed differences in Sirt1 between Jinhua pigs (a fatty breed of China) and Landrace pigs (a leaner breed). In addition, the effect of insulin on the gene expression of Sirt1 and the major lipase, adipose triglyceride lipase (ATGL), and hormone-sensitive lipase (HSL) in fat metabolism was also studied in vitro. Compared with the Landrace pigs, the BW of Jinhua pigs was less, whereas the body fat content were greater. The protein content and the mRNA abundance of Sirt1 in Jinhua pigs were less in subcutaneous adipose tissues compared with the Landrace pigs. Likewise, the mRNA abundance of ATGL and HSL were also less in Jinhua pigs. In vitro, treatment with a different dose of insulin (10, 50 and 100 nM) decreased glycerol release and the mRNA abundance of Sirt1, ATGL, and HSL in porcine adipocytes. Likewise, treatment with 50 nM insulin for 24 and 48 h also decreased glycerol release and the expression of Sirt1, ATGL, and HSL in porcine adipocytes. Furthermore, insulin and Sirt1-specific small interfering RNA treatment decreased the expression of Sirt1, ATGL, and HSL compared with the control or insulin treatment. These results indicate that insulin may regulate transcription of Sirt1, ATGL, and HSL in porcine adipocytes and provide information for manipulating these gene expressions in regulating fat metabolism in pigs.

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Comparison of a wheat-based diet supplemented with purified β-glucans, with an oat-based diet on nutrient digestibility, nitrogen utilization, distal gastrointestinal tract composition, and manure odor and ammonia emissions from finishing pigs

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It was hypothesized that supplementation of an oat-extracted mixed-linkage (1→3), (1→4)-β-d-glucan (β-glucans) to a wheat-based diet may beneficially mitigate manure odor and ammonia emissions associated with intensive pig production, without depressing nutrient digestibility as has been observed with oat-based diets. An experiment was conducted to investigate the effect of dietary β-glucan source and the inclusion of an enzyme composite containing β-glucanase on energy and nutrient digestibility, N utilization, distal gastrointestinal tract (GIT) fermentation, and manure emissions from finisher boars. Twenty-eight boars (BW = 74.2 kg) were assigned to 1 of 4 dietary treatments (n = 7/treatment): 1) an oat-based diet (oat), 2) an oat diet + enzyme composite (OE), 3) a wheat-based diet + purified β-glucans (WG), and 4) a wheat-based diet + purified β-glucans + enzyme composite. The wheat-based diets containing purified β-glucans were formulated to contain concentrations of total β-glucans comparable with the oat based diet. Consumption of the WG diet resulted in a greater digestibility of GE and an increase in the urine: feces N excretion ratio compared with the oat diet. In the distal GIT, pigs offered the WG diet contained fewer bifidobacteria and lactobacilli compared with the oat diet. Pigs offered the WG diet had increased manure odor emissions compared with the oat diet. In conclusion, although supplementing wheat-based diets with extracted oat-β-glucan did not reduce nutrient digestibility, there was a negligible effect in beneficially influencing manure emissions from pigs when compared with a conventional oat formulation.

For more information the full article can be found at http://jas.fass.org/