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1.
A study was conducted with 20 weaned barrows (14 d, 4.98 +/- .21 kg) to determine the effect of spray-dried plasma (SDP) on the pig's immune response to a lipopolysaccharide (LPS) challenge. After weaning, pigs were fed a diet containing 0 or 7% SDP for 7 d. On d 6 postweaning, all pigs were fitted with a jugular catheter. On d 7 postweaning, the pigs were given an i.p. injection of either saline or LPS (150 microg/kg BW) followed by a 3-h blood collection every 15 min. Following blood collection, all pigs were killed and tissue was collected for mRNA analysis. Additionally, the small intestine was collected for measurement of villus height, crypt depth, and villus height:crypt depth ratio (VCR) at three sites (25, 50, and 75% of the total length). Feeding SDP resulted in reduced (P < 0.05) mRNA expression of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) mRNA in the adrenal gland, spleen, hypothalamus, pituitary gland, and liver. Additionally, expression of IL-6 mRNA was reduced (P < 0.05) in the spleen and pituitary gland for pigs fed SDP. For pigs fed the diet with SDP, LPS administration did not affect (P > 0.10) cytokine mRNA expression, whereas LPS reduced expression of TNF-alpha mRNA in the spleen and IL-1beta mRNA in the adrenal gland, spleen, and thymus for pigs fed the diet without SDP. For pigs fed the diet with SDP, LPS caused serum TNF-alpha to increase 150-fold compared to a 60-fold increase for pigs fed the diet without SDP. Similarly, interferon-gamma (IFN-gamma) increased 110-fold for pigs fed the diet with SDP compared to a 16-fold increase for pigs fed the diet without SDP. For pigs fed the diet with SDP, LPS caused major villus atrophy, whereas for pigs fed the diet without SDP, LPS had no effect on intestinal morphology. These results demonstrate that the basal activation of the immune system appears to be less for pigs fed the diet with SDP compared to pigs fed the diet without SDP after weaning. Additionally, for pigs fed the diet with SDP, there appeared to be an overresponse of the immune system following LPS administration, which resulted in major damage to the mucosa of the gastrointestinal tract.  相似文献   

2.
A total of 108 crossbred piglets (7.75 +/- 0.24 kg of BW) weaned at 28 d was used to study the interactive effects of beta-glucan obtained from the Chinese herb Astragalus membranaceus (AM) and Escherichia coli lipopolysaccharide (LPS) challenge on performance, immunological, adrenal, and somatotropic responses of weaned pigs. The treatments were in a 2 x 3 factorial arrangement; main effects were level of Astragalus membranaceus glucan (AMG; 0, 500, or 1,000 mg/kg; as-fed basis) and presence of immunological challenge (with or without LPS). The experiment included six replicate pens per treatment and three pigs per pen. Lipopolysaccharide challenges were conducted on d 7 and 21 of the trial. Blood samples were obtained from the vena cava from one pig per pen at 3 h after LPS challenge to determine plasma responses. Weight gain and feed:gain ratio were unaffected by glucan. However, there was a quadratic effect on feed intake (P < 0.05): pigs fed 500 mg of glucan/kg had the highest feed intake. Immunological challenge with LPS decreased weight gain (P = 0.02). An interaction (P = 0.01 to 0.09) between AMG and LPS was observed for glucose, IL-1beta, PGE2, and cortisol. Astragalus membranaceus glucan had a quadratic effect on the plasma concentrations of glucose, IL-1beta, PGE2, and cortisol (P < 0.05) after both LPS challenges. Plasma concentrations of glucose, IL-1beta, PGE2, and cortisol (P < 0.05) were all increased in LPS-challenged pigs compared with the control pigs after both LPS challenges. The IGF-I concentrations were less for LPS-challenged pigs than for unchallenged pigs. The lymphocyte proliferation response of peripheral blood induced by 5 microg of concanavalin A/mL (P < 0.01) and IL-2 bioactivity (P < 0.05) increased linearly with increasing addition of glucan. Pigs challenged with LPS had greater T-lymphocyte proliferation (P = 0.06) and IL-2 bioactivity (P = 0.07) than unchallenged pigs after the first immunological challenge but not after the second. In conclusion, although glucan did not improve pig performance under the conditions of the present experiment, when included at 500 mg/kg, it decreased the release of inflammatory cytokine and corticosteroid and improved the lymphocyte proliferation response of weanling piglets via enhanced IL-2 bioactivity.  相似文献   

3.
Two experiments were conducted to evaluate the efficacy of beta-glucan on growth performance, nutrient digestibility, and immunity in weanling pigs. In Exp. 1, 210 weanling pigs (6.38 +/- 0.92 kg of BW) were fed dietary beta-glucan (0, 0.01, 0.02, 0.03, or 0.04%) for 5 wk. In Exp. 2, 168 pigs (6.18 +/- 1.31 kg of BW) were fed no beta-glucan or antibiotics (T1), 0.02% beta-glucan (T2), only antibiotics (T3), or 0.02% beta-glucan with antibiotics (T4) for 8 wk. In Exp. 2, the antibiotics fed were apramycin and carbadox in phase I (0 to 2 wk) and carbadox and chlortetracycline in phase II (3 to 8 wk). During Exp. 2, the performance study was conducted for 5 wk, and the immune response was tested until 8 wk. In Exp. 1, there was a trend for a linear increase (P = 0.068) in ADG as the dietary beta-glucan concentration increased in the diet. The digestibilities of DM, GE, CP, ether extract, Ca, and P increased linearly (P < 0.05) in the beta-glucan-supplemented pigs. In Exp. 2, the overall ADG was greater (P < 0.05) in treatment T4 compared with the control group (T1). Also, except for P, this group showed greater (P < 0.05) nutrient digestibilities than the control group. In Exp. 2, at d 15, 24, and 46 antibody titers were measured by ELISA against Pasteurella multocida type A and D after vaccination with atrophic rhinitis, and they differed significantly (P < 0.05) with no particular trend. Flow cytometry was used to determine porcine lymphocyte subpopulations at 4 and 8 wk of Exp. 2. There was an increase in CD4 cells (P < 0.05) and a trend for an increase in CD8 cells (P < 0.10) at 8 wk in pigs fed the T2 diet compared with the other groups. Overall, increasing the dietary concentrations of beta-glucan did not improve ADG without antibiotic, and in weanling pigs antibiotics seem to be more effective in improving nutrient digestibilities and growth performance than beta-glucan.  相似文献   

4.
The effect of reduced pig growth rate postweaning as a result of restricted floor space and feeder trough space on subsequent growth to slaughter was investigated in a wean-to-finish system. Crossbred pigs (n = 1,728) were used in a randomized block design with a 2 x 2 x 2 factorial arrangement of treatments: 1) floor space (high [0.630 m2/pig] vs. low floor space [0.315 m2/pig]), 2) feeder trough space (unrestricted [4 cm/pig] vs. restricted feeder trough space [2 cm/pig]), and 3) period of imposing floor- and feeder-trough-space treatments (12 vs. 14 wk postweaning). Growth performance was measured from weaning (5.5 +/- 0.01 kg of BW; 17 d of age) to slaughter (the end of wk 25 postweaning). From the end of the treatment period to the end of wk 25, pigs on all treatments had the same floor and feeder trough space. Pigs with low floor space had lower (P < 0.01) ADG, ADFI, and gain:feed ratio than those with high floor space, and were therefore lighter (P < 0.05) at the end of the postweaning treatment period. Pigs given the restricted feeder trough space had lower (P < 0.05) ADFI, similar (P > 0.05) ADG, and higher (P < 0.01) gain:feed ratio than those with unrestricted feeder trough space during the treatment period. Pigs in the 14-wk treatment period had higher (P < 0.01) ADG and ADFI, but lower gain:feed than those in the 12-wk treatment during that period. In the subsequent period, from the end of treatment to wk 25, there was an interaction (P < 0.05) between floor space and treatment period; the difference in ADG and gain:feed for pigs on low vs. high floor space was greater for the 14-wk than the 12-wk treatment period. However, low-floor-space pigs tended (P = 0.06) to be lighter than high-floor-space pigs at the end of wk 25 postweaning. Neither feeder trough space nor treatment period affected pig growth performance during the period from the end of treatment to wk 25. Carcass backfat and longissimus depths at the end of wk 25 were not influenced (P > 0.05) by treatment. In summary, pigs with restricted growth due to low floor space until either 12 or 14 wk postweaning had increased growth and feed efficiency in the subsequent period to wk 25 postweaning, with only a slight effect on BW and no effect on carcass measures.  相似文献   

5.
Three experiments were conducted to investigate the effects of beta-glucan supplementation on pig performance and immune function. In Exp. 1, 100 weaned pigs (8.65 +/- 0.42 kg of BW and 28 +/- 2 d of age) were used in a 35-d experiment to determine the effects of graded levels of beta-glucan. Pigs were randomly allotted to 1 of 5 treatments containing beta-glucan supplemented at 0, 25, 50, 100, or 200 ppm. Each treatment was replicated using 5 pens containing 4 pigs per pen. The ADG of pigs between d 14 to 28 and d 0 to 28 responded to dietary beta-glucan in a quadratic fashion (P < 0.05), whereas beta-glucan had no effect on ADFI and G:F in any period. In Exp. 2, 80 crossbred pigs (8.23 +/- 0.56 kg of BW and 28 +/- 2 d of age) were used in a 35-d experiment. Pigs were allotted to 1 of 2 dietary treatments (0 or 50 ppm of beta-glucan in the diet) using 10 pens with 4 pigs per pen. Pigs treated with beta-glucan had greater ADG in the 14- to 28-d (P = 0.05) and 0-to 28-d (P = 0.035) periods. The ADFI of pigs receiving beta-glucan was increased (P < 0.05) in the periods from 0 to 14, 0 to 28, and 28 to 35 d. The lymphocyte proliferation index in response to phytohemagglutinin (P = 0.051) and concanavalin A (P = 0.052) tended to decrease on d 14 in pigs supplemented with beta-glucan compared with pigs without supplementation. In Exp. 3, 24 barrows (8.89 +/- 0.20 kg of BW and 28 d of age) were used to investigate the immunological and somatotropic responses of pigs challenged with lipopolysaccharide (LPS). Experimental treatments were arranged in a 2 x 2 factorial, with the main effects of LPS challenge (saline vs. LPS) and dietary addition of beta-glucan (0 vs. 50 ppm). Pigs were raised individually in metabolic cages. Pigs were fed 0 or 50 ppm of beta-glucan for 28 d and then challenged with LPS (25 microg/kg of BW) or saline. After LPS injection, blood was obtained at 0, 1.5, 3, 4.5, 6, and 7.5 h to determine cytokine production and the somatotropic response. Dietary beta-glucan increased plasma interleukin-6 at 1.5, 3, and 4.5 h and tumor necrosis factor-alpha at 3 and 4.5 h and increased plasma interleukin-10 from 3 to 7.5 h after LPS challenge. The beta-glucan treatments had no effect on growth hormone. In conclusion, beta-glucan can selectively influence performance and partially offer benefits on somatotropic axis and immune function in weaned piglets challenged with LPS.  相似文献   

6.
Two studies were carried out with the same group of pigs within a wean-to-finish system. In Study 1 (weaning to wk 8 postweaning), the effect of feeder-trough space in pens that were double-stocked on pig growth was evaluated. In Study 2 (end of wk 8 to 112 +/- 1.5 kg BW), the effect of variation in pig BW within a pen on growth was investigated. In Study 1, a randomized block design was used to compare two feeder-trough space treatments (Double [4 cm/pig] vs Control [2 cm/pig]). Pigs (n = 1,728) were randomly allocated at weaning (5.4 +/- 0.01 kg BW; 16 d of age) to mixed-sex pens (8 pens/treatment) of 108 pigs/pen on the basis of BW. Floor-space (0.30 m2/pig) and drinker allocation (13 pigs/drinker) were the same for both treatments. Two six-place (35 cm/place) feeders were positioned together in the center of each pen and were accessible from both sides. For the Double treatment, both feeders contained feed, whereas for the Control only one feeder contained feed. In Study 2, a randomized block design was used to compare three BW/variation in BW treatments: 1) Heavy BW/Low variation, 2) Light BW/Low variation, and 3) Mixed BW/Normal variation. The double-stocked pens of pigs from within previous feeder-trough space treatment were split into two groups of 54 pigs (equal sex ratio) having either high or low BW variation within pen. Pigs had free access to feed and water throughout the studies. In Study 1, doubling feeder-trough space did not affect (P > 0.05) pig growth from weaning to the end of wk 6. From wk 6 to 8, pigs on the Double treatment compared to the Control treatment had higher (P < 0.05) ADG and were heavier (P < 0.05), but had similar (P > 0.05) ADFI and gain:feed ratio. In Study 2, pen-BW treatment did not impact (P > 0.05) ADG or gain:feed ratio; however, Heavy/Low had greater (P < 0.01) ADFI than Light/Low with Mixed/Normal being intermediate for ADFI. At 112 kg BW, CV of BW within a pen was similar (P > 0.05) across treatments; however, days to market BW was greater (P < 0.001) for Light/Low than Heavy/ Low with Mixed/Normal being intermediate. In summary, increasing feeder-trough space from 2 to 4 cm per pig increased daily gain after wk 6 postweaning in double-stocked pens of pigs; however, sorting pigs on the basis of BW when splitting pens did not impact growth rate or variation in BW within a pen at market BW.  相似文献   

7.
Forty barrows (TR4 x C22) were weaned at 17 d of age (BW = 6.27 +/- 0.30 kg), housed (two pigs/pen) in a thermal-neutral environment (TN; constant 26.7 degrees C), and fed diets with or without 7% (as-fed basis) spray-dried plasma (SDP). On d 7, one pig/ pen was moved into a cold environment (CE; constant 15.6 degrees C). Pigs were fitted with jugular catheters on d 11. On d 12, 16 pigs per environment (eight pigs per dietary treatment) were challenged i.v. with 75 microg of lipopolysaccharide (LPS)/kg of BW. Blood samples were collected over a 4.5-h period. Pigs were then killed and tissue samples were harvested for messenger RNA (mRNA) analysis. From d 0 to 7, pigs fed SDP diets had a lower gain:feed ratio (G/F) than pigs fed no SDP (533 +/- 14 vs. 585 +/- 17 g/kg; P < 0.03). Pigs housed in the CE consumed more feed and had a lower G/F than pigs housed in TN from d 7 to 11 (P < 0.001). There were no environment x diet interactions from d 7 to 11 (P > 0.78). Baseline concentrations of serum ACTH and cortisol were lower in the TN pigs than in the CE pigs (P < 0.001). Pigs fed diets without SDP had lower serum cortisol concentrations over the 4.5-h period than pigs fed SDP (time x diet, P < 0.001). Serum concentrations of tumor necrosis factor-alpha (TNF-alpha) were highest for pigs consuming SDP in the CE, whereas there were no differences among the other treatments (time x diet x environment, P < 0.02). Pigs housed in the CE had higher serum interleukin-1beta (IL-1beta) (P < 0.001) and interleukin-6 (IL-6; P < 0.001) than TN pigs. Pigs fed SDP also had slightly higher serum IL-1beta concentrations (P < 0.10) and higher (P < 0.001) IL-6 concentrations than pigs fed no SDP. Pigs fed SDP had 9% lower liver and 13% lower thymus mRNA expression of tumor necrosis factor-alpha (TNF-alpha) than pigs that consumed no SDP (P < 0.06). Liver IL-1beta, IL-6, and LPS-binding protein mRNA were higher in the CE than in the TN (P < 0.03, P < 0.001, and P < 0.05; respectively). In addition, spleen TNF-alpha (P < 0.03) and IL-6 (P < 0.01) mRNA levels were higher in the CE than in the TN. Pigs consuming SDP and challenged with LPS responded with elevated serum concentrations of cortisol and cytokines compared with pigs fed diets with no SDP. Housing pigs in a CE increased the baseline concentrations of ACTH and cortisol, and when coupled with an LPS challenge, resulted in elevated serum and tissue mRNA levels of cytokines. Cold stress and feeding SDP during a LPS challenge may result in increased stress and immune responses in young pigs.  相似文献   

8.
Two experiments evaluated the relationship of vitamin E (source and level) and vitamin A (level) on the apparent absorption and retention of both vitamins in weaned pigs. Both experiments used a combined total of 460 crossbred pigs ([Yorkshire x Landrace] x Duroc), housed in elevated 1.2- x 1.2-m crates containing five pigs per pen. Experiment 1 was a 2 x 2 x 2 factorial arrangement of treatments in a randomized complete block design conducted in seven replicates. Levels of vitamin A (2,200 or 13,200 IU/kg), vitamin E (15 or 90 IU/kg), and two vitamin E sources (D-alpha-tocopheryl acetate [D-TAc] or DL-alpha-tocopheryl acetate [DL-TAc]) were evaluated over a 35-d period. Vitamin A or E levels and the two vitamin E sources did not affect pig performances to 20 kg BW. Serum retinol and alpha-tocopherol concentrations increased (P < 0.01) as the dietary level of each vitamin increased. Serum alpha-tocopherol declined as dietary vitamin E level increased when vitamin A level increased resulting in an interaction (P < 0.05). Serum alpha-tocopherol concentrations were higher (P < 0.05) at 35-d postweaning when D-TAc was the vitamin E source. Experiment 2 was a 3 x 2 factorial arrangement of treatments conducted in six replicates. Three levels of vitamin A (2,200, 13,200, or 26,400 IU/ kg) and two sources of vitamin E (D-TAc or DL-TAc) each provided at 40 IU/kg diet were evaluated over a 35-d period. Pig performances to 35-d postweaning were not affected by the dietary variables. Serum alpha-tocopherol (P < 0.01) and retinol (P < 0.05) concentrations increased as their respective vitamin level increased. Serum (P < 0.05) and liver (P < 0.01) alpha-tocopherol concentrations both declined as dietary vitamin A levels increased resulting in interaction responses. Serum alpha-tocopherol concentration was higher (P < 0.05) at 35-d postweaning when d-TAc was the vitamin E source. Dietary vitamin E sources had no effect on serum or liver retinol concentrations. These results demonstrated that both supplemental vitamin A and vitamin E increased in the blood as their dietary levels increased. However, as dietary vitamin A level increased, serum and liver alpha-tocopherol concentrations declined, suggesting a reduced absorption and retention of alpha-tocopherol when weaned pigs were fed high dietary vitamin A levels.  相似文献   

9.
The relationship of injected Fe doses on blood hematology and pig growth performance during both preweaning and postweaning periods was studied. In Exp. 1, the effect of BW of 347 pigs injected with 200 mg of Fe (dextran) intramuscularly (i.m.) at birth on hemoglobin (Hb) and percent hematocrit (Hct) at weaning was assessed. As BW increased there was a decline (P < 0.01) in Hb and Hct. In Exp. 2, Fe injection doses and timing of injected Fe on blood hematology and pig growth were evaluated. Injections were as follows: 1) 200 mg of Fe at birth; 2) 300 mg of Fe at birth; or 3) 200 mg of Fe at birth + 100 mg of Fe at d 10. A total of 269 pigs were allotted within litter to 3 treatments. The 2 greater quantities of injected Fe (i.e., 300 or 200 + 100 mg of Fe) had similar but greater (P < 0.05) Hb and Hct values than pigs receiving 200 mg of Fe, but growth rates were similar at weaning. The effects of injecting 200 mg of Fe at birth and either saline or 100 mg of Fe at 10 d of age were investigated in Exp. 3. Weaned pigs of each group were fed diets with 0, 80, or 160 mg/kg of added Fe for 35 d as a 2 × 3 factorial arrangement with 12 replicates (n = 360 pigs) in a randomized complete block design (RCB). The innate Fe contents of diets averaged 200 mg/kg. The greater Fe injection group (200 + 100 mg) had greater (P < 0.01) Hb and Hct values through 14 d postweaning (P < 0.05) and greater (P < 0.01) Hct values through 21 d postweaning. As dietary Fe increased, Hb was greater only at d 14 (P < 0.05 4), whereas Hct increased linearly to d 35 (P < 0.01) postweaning. Dietary Fe resulted in linear increases (P < 0.01) in ADG from d 21 to 35 and d 0 to 35. In Exp. 4, 3 dietary Fe (80, 160, and 240 mg/kg of diet), 2 injected Fe treatments (200 or 300 mg of Fe) at birth, and birth BW (<1.5 or ≥1.5 kg) were evaluated as a 2 × 2 × 3 factorial arrangement of treatments in a RCB design with 6 replicates (n = 280 pigs). The 300 mg of Fe injection group had lighter BW in both birth BW groups, with a birth BW × injected Fe interaction (P < 0.01). This resulted in the lighter birth BW pigs receiving 200 mg of Fe having greater BW gains to 240 mg/kg of dietary Fe, whereas light birth BW pigs injected with 300 mg of Fe plateaued at 160 mg/kg of Fe. Pigs in the heavy birth BW group injected with 200 or 300 mg of Fe at birth responded similarly to dietary Fe postweaning. These results indicate that blood Hb and Hct were affected by pig BW at weaning, but the additional 100 mg of Fe i.m. at 10 d of age increased blood hematology and that Fe injected preweaning affected initial postweaning performance.  相似文献   

10.
Two experiments were conducted to evaluate dietary fortification levels of a B vitamin pre-mix for starter and grower-finisher pigs on subsequent performance responses. The objective was to determine whether the modern pig requires higher dietary levels of B vitamins than estimated by the NRC (1998). Both experiments added fat-soluble vitamins at the requirement levels (NRC, 1998) in all diets, whereas the B vitamins were added at 0, 100, 200, or 400% of the total NRC (1998) requirement levels for the starter and grower pig. Indigenous vitamin contributions from the feed grains were not included in the estimates. Each station used the same vitamin premixes but incorporated its own grain sources in the diets. The first experiment was conducted across 7 stations (Indiana, Ohio, Oklahoma, Michigan, Missouri, Nebraska, Texas) and involved 660 pigs in a randomized complete block design in 30 replicates. Complex nursery diets were fed in 2 phases. The first phase (0 to 14 d postweaning) and second phase (15 to 35 d postweaning) diets were formulated to Lys (total) levels of 1.50 and 1.30%, respectively. The results demonstrated no performance response to addition of B vitamins from 0 to 14 d post-weaning, but performances increased quadratically (P < 0.01) to the 100% NRC level from 14 to 35 d postweaning and for the overall 35-d period. The second experiment was conducted across 3 stations (Ohio, Nebraska, and South Dakota) and involved 216 pigs in a randomized complete block design in 10 replicates. Corn-soybean meal mixtures were fed in 3 phases formulated to total Lys levels of 1.30% (23 to 55 kg of BW), 1.00% (55 to 85 kg of BW), and 0.78% (85 to 120 kg of BW). Pig performances increased (P < 0.01) to the 100% B vitamin level from 23 to 85 kg of BW, but there was no response to any level from 85 to 120 kg of BW. Carcass measurements demonstrated a greater LM area (P < 0.01) and a lower backfat depth (P < 0.01) to the 100% B vitamin level. One station evaluated an additional treatment (3 replicates) in which each replicate was fed a fifth diet containing the 100% dietary level of B vitamins from 23 to 85 kg of BW whereupon the B vitamins were removed from 85 to 120 kg of BW. This removal did not reduce pig performance responses for the final period or for the overall period. The results demonstrated that supplementation of B vitamins at the 100% total NRC levels for starter and grower pigs was sufficient to meet their needs, and there was no further improvement to or deleterious effect to greater dietary levels.  相似文献   

11.
Two experiments were conducted to determine the effects of dietary sodium butyrate on growth performance and response to Escherichia coli lipopolysaccharide (LPS) in weanling pigs. In a 28-d experiment, 180 pigs (initial BW 6.3 kg) were fed 0, 0.05, 0.1, 0.2, or 0.4% sodium butyrate, or 110 mg/kg of dietary tylosin. There was no effect of dietary sodium butyrate or tylosin on overall G:F, but there was a linear trend (P < 0.07) toward decreased ADFI and ADG as levels of sodium butyrate increased. In a second 28-d experiment, 108 pigs (initial BW 6.3 kg) were assigned to 1 of 3 dietary treatments: 1) no antibiotics, 2) 0.2% sodium butyrate, or 3) 55 mg/kg of carbadox. On d 14, a subset of pigs from the no-antibiotic and butyrate treatment groups was challenged with E. coli LPS or injected with sterile saline in a 2 x 2 factorial arrangement (+/-LPS challenge; +/-dietary butyrate; n = 6 pigs/treatment group). Four hours after LPS challenge, blood samples were obtained, and samples of LM, liver, and ileum were collected for gene expression analysis. Serum samples were analyzed for IL-6, tumor necrosis factor alpha (TNFalpha), alpha(1)-acid glycoprotein, cortisol, IGF-I, insulin, and metabolites. The relative abundance of tissue cytokine and IGF-I mRNA was measured by real-time PCR. Feeding diets containing sodium butyrate or carbadox did not alter ADG or ADFI compared with pigs fed the control diet. From d 0 to 14, pigs fed diets containing 0.2% sodium butyrate had decreased (P < 0.05) ADG and tended (P < 0.06) to have decreased G:F compared with animals fed diets containing carbadox. Challenge with LPS increased (P < 0.05) serum cytokines and cortisol and decreased (P < 0.05) serum glucose and triglycerides. Injection with LPS increased (P < 0.05) the relative abundance of hepatic IL-6 and TNFalpha mRNA, increased (P < 0.05) LM TNFalpha mRNA content, and decreased (P < 0.05) IGF-I mRNA in LM. For serum cortisol, there was an interaction (P < 0.05) between dietary butyrate and LPS. The increase in serum cortisol attributable to LPS was greater (P < 0.05) in pigs fed butyrate than in pigs fed the control diet. There tended (P < 0.10) to be an interaction between LPS and diet and for butyrate to increase the relative abundance of IL-6 mRNA in LM. Carbadox did not alter cytokine or IGF-I mRNA or serum metabolites, but did decrease (P < 0.05) serum TNFalpha. These data indicate that dietary sodium butyrate does not enhance growth performance, but may regulate the response to inflammatory stimuli in weanling pigs.  相似文献   

12.
We evaluated the effect of raw potato starch (RPS) on growth performance, postweaning diarrhea, and gastrointestinal microbial populations in weaned piglets. Eighty-four piglets were weaned at 17 +/- 2 d of age with an average BW of 6.0 +/- 0.9 kg. Pigs were blocked by BW and assigned to 1 of 4 diets in a randomized complete block design with 7 replicate pens per diet and 3 pigs per pen. Treatments were 1) a positive control (PC) containing an antibiotic, 2) a negative control (NC) with no RPS and no antibiotic, 3) NC + 7% RPS (7% RPS), and 4) NC + 14% RPS (14% RPS). Diets were corn-wheat-soybean meal-based and formulated to meet NRC (1998) recommendations. The ADG, ADFI, and G:F ratio were determined weekly. Fecal consistency (FC) scoring was determined daily. After wk 3, 1 pig with a BW closest to the pen mean was killed to evaluate ileal and colonic mucosal-attached Escherichia coli and lactic acid bacteria, as well as digesta pH, VFA, and ammonia N concentrations. The DNA was extracted from ileum and colon digesta and used for molecular microbial evaluations using terminal-RFLP analysis of 16S rDNA genes. The ADG for wk 1 was greater (P < 0.01) for the PC diet, but diet had no effect on ADG during wk 3. The ADFI did not differ among treatments during the first 2 wk, and ADFI was least for 7% RPS diet during wk 3. The NC diet had a greater (P < 0.05) FC score during wk 1 than other treatments, but diet had no effect on FC score during wk 2 and 3. Diets had no effect on the colon lactic acid bacterial counts; however, the PC diet had decreased (P < 0.05) colon E. coli counts than other treatments. Ileum and colon digesta pH and total VFA concentrations did not differ among treatments. Pigs fed with 7 and 14% RPS diets had greater (P < 0.05) ileum ammonia N concentration compared with pigs fed with other diets. There was more diarrhea (P < 0.05) in the 14% than the 7% RPS and control treatments at d 21. This difference correlated with a decline (P < 0.05) in microbial diversity in the colon. We concluded that 7% RPS can be used to prevent postweaning diarrhea in weaned piglets, but there are no effects on growth performance.  相似文献   

13.
The effects of high ambient temperature and level of dietary heat increment on sow milk production and piglet performance over a 28-d lactation were determined in 59 multiparous crossbred Large White x Landrace pigs kept at a thermoneutral (20 degrees C) or in a hot (29 degrees C) constant ambient temperature. Experimental diets fed during lactation were a control diet (NP; 17.6% CP) and two low-protein diets obtained by reduction of CP level (LP; 14.2% CP) or both reduction of CP and addition of fat (LPF; 15.2% CP); the NE:ME ratio was 74.3, 75.6, and 75.8% for NP, LP, and LPF diets, respectively. All diets provided 0.82 g of digestible lysine/MJ of NE, and ratios between essential AA and lysine were above recommendations. Creep feed was provided after d 21 of lactation. Reduction of CP level did not influence (P > 0.10) milk production, milk composition, or piglet performance. Despite higher nursing frequency (39 vs 34 sucklings per day), milk production decreased (P < 0.01) from 10.43 to 7.35 kg/d when temperature increased from 20 to 29 degrees C. At d 14, DM (18.6 vs 18.1%) and energy (4.96 vs 4.75 MJ/kg) contents in milk tended (P = 0.09) to be higher in sows kept at 29 degrees C. Over the 28-d lactation, piglet BW gain and BW at weaning decreased (P < 0.01) from 272 to 203 g/d and 9.51 to 7.52 kg, respectively, when temperature increased from 20 to 29 degrees C. Daily creep feed intake over the 4th wk of lactation was higher (P < 0.01) at 29 degrees C than at 20 degrees C (388 vs 232 g/litter, respectively), which was reflected in a greater increase in BW gain between wk 1 to 3 and wk 4 at the higher temperature (147 vs 130%); BW gain between weaning and d 14 postweaning was higher (P < 0.05) for piglets originating from sows kept at 29 degrees C (280 vs 218 g/d). In connection with their lower growth rate, DM (31.2 vs 33.0%), protein (15.5 vs 16.0%), lipid (12.3 vs 13.9%), and energy (8.39 vs 9.09 kJ/g) contents in weaned, slaughtered piglets were lower (P < 0.01) at 29 than at 20 degrees C. In conclusion, modification in the CP:NE ratio in order to decrease dietary heat increment did not affect milk production and piglet performance in thermoneutral or hot climatic conditions. Our results confirm the negative effect of high ambient temperatures on milk yield and emphasize the importance of creep feed supply to improve pre- and postweaning growth of piglets in these conditions, especially when weaning occurs after 3 wk of age.  相似文献   

14.
The objective was to evaluate the effect of restricted early postweaning growth rate due to diet complexity, pen space, or both on subsequent growth to market in a wean-to-finish system. Pigs (n = 1,728) were used in a randomized block design with a 2 x 2 factorial arrangement of treatments: 1) diet complexity (Complex vs Simple) and 2) space allocation (Unrestricted vs Restricted). Treatments were imposed for the first 8 wk after weaning (period 1) and growth was measured from weaning (5.0 +/- 0.01 kg body weight; 15 d of age) to the end of wk 23 postweaning. The Simple diet was based on corn-soybean meal with minimal inclusion of milk products, processed cereals, and animal protein-based ingredients compared to the Complex diet. Floor and feeder-trough spaces were 0.63 m2 and 4 cm and 0.21 m2 and 2 cm per pig for Unrestricted and Restricted space treatments, respectively. From the end of wk 8 to end of wk 23 (period 2), pigs on all treatments had the same floor and feeder spaces and were fed common diets. There was no interaction (P > 0.05) between diet and space treatments. In period 1, Simple diets resulted in similar average daily feed intake (ADFI; 639 vs 650 +/- 5.4 g; P > 0.05), but lower average daily gain (ADG; 408 vs 424 +/- 3.8 g; P < 0.01) and gain:feed ratio (0.64 vs 0.65 +/- 0.002; P < 0.001), and lighter body weight (2.8%; P < 0.01) compared to the Complex diets. In period 2, growth was not affected (P > 0.05) by previous diet complexity, and pig body weight was similar (114.4 vs 114.4 +/- 0.37 kg, P > 0.05) at the end of wk 23. In period 1, pigs with Restricted space had lower ADG (398 vs 434 +/- 3.8 g; P < 0.001), ADFI (621 vs 668 +/- 5.4 g; P < 0.001), and gain:feed ratio (0.64 vs 0.65 +/- 0.002; P < 0.01), and were lighter at the end of wk 8 (6.5%; P < 0.001) than those with Unrestricted space. However, in period 2, pigs with Restricted space had higher (P < 0.01) ADG (3%), ADFI (2%), and gain:feed ratio (3%) than those with Unrestricted space, and body weight was similar (114.5 vs 114.3 +/- 0.37 kg; P > 0.05) at end of wk 23. Carcass backfat and loin-eye depth at market body weight were influenced by neither diet nor space treatment. Using a simple diet program and restricted space allowance immediately postweaning resulted in a lower early growth rate, but had no impact on pig body weight or carcass measures at market.  相似文献   

15.
Certain high lean gain swine genotypes have greater sensitivity to pathogen and nonpathogen stressors evident by reduced productivity and increased mortality during disease stress or in suboptimal production environments. Saline (control) and an immunologic challenge (LPS; 25 microg lipopolysaccharide/kg BW) were administered to three genetic populations (each pig used as its own control): high lean (H), moderate lean terminal cross (MT), and moderate lean maternal cross (MM). LPS induced anorexia, and significantly increased body temperature and circulating TNF-alpha, cortisol, and NEFA in all genotypes (P < 0.0004). LPS reduced circulating glucose, insulin, and IGF-1 in all genotypes (P < 0.05). The LPS-induced hypoglycemia was significantly greater in MM versus MT and H pigs (P < 0.03). The hypoinsulinemia was significantly greater in MM versus H pigs (P < 0.02). MM pigs recovered from hypoinsulinemia slower than MT pigs (P < 0.03). Control insulin was higher in H versus MT pigs (P < 0.08), but relative to basal, the insulin response to LPS was similar. Plasma haptoglobin response to LPS was lower for MM versus MT and H pigs (P < 0.02), and tended to be lower in MT versus H pigs (P < 0.09). LPS treatment caused similar decreases in plasma IGF-1 concentrations among genotypes. Ten hours after LPS treatment, leptin mRNA abundance in adipose tissue was significantly reduced (relative to control) in MM and H pigs (P < 0.02) but not in MT pigs (P > 0.05). Physiological differences in leptin, a potent regulator of food intake and energy metabolism, may be important factors in the genetic variation in sensitivity to environmental stress.  相似文献   

16.
Two studies were carried out in different wean-to-finish barns to determine the effects of double stocking on pig growth performance. In Study 1, pigs (n = 1,560) were used in a randomized complete block design with a 2 x 2 factorial arrangement of treatments: initial stocking treatment (Single [52 pigs/pen] vs Double [104 pigs/pen] stocked for 10 wk after weaning) and weighing frequency (High [12 times during the study] vs Low [3 times]) on pig performance from weaning (5.9+/-0.01 kg BW; 17 d of age) to harvest (114+/-0.67 kg BW). Floor and feeder space per pig were 0.650 m2 and 4 cm and 0.325 m2 and 2 cm for the single- and double-stocked treatments, respectively. In Study 2, pigs (n = 1,458) were used in a randomized complete block design to evaluate two initial stocking treatments (Single [27 pigs] vs Double [54 pigs] stocked for 10 wk after weaning) on pig performance from weaning (4.8+/-0.01 kg BW; 15 d of age) to harvest (24 wk after weaning). Floor and feeder space per pig were 0.640 m2 and 3.4 cm and 0.320 m2 and 1.7 cm for single- and double-stocked pens, respectively. In both studies, double-stocked pigs were split at the end of wk 10 into two equal-sized groups of similar mean BW and CV of BW, and one group was moved to a different pen in the same building. In Study 1, performance was not affected (P > 0.10) by frequency of weighing. For the first 10 wk after weaning, the Double compared to the Single treatment had lower ADG (7.7 and 7.9%, for Studies 1 and 2, respectively; P < 0.001) and lighter pigs at wk 10 (6.8 and 7.3%, respectively; P < 0.001). During the first 10 wk in Study 1, Double compared to the Single pigs had lower ADFI (7%; P < 0.001) but similar gain:feed (P > 0.10). From wk 11 to harvest, pigs on Double and Single treatments had similar (P > 0.10) ADG in both studies and, in Study 1, ADFI was unaffected by initial stocking treatment, but double-stocked pigs had greater gain:feed (4%, P < 0.01). Double-stocked pigs required an additional 2 d to reach a fixed harvest BW (P < 0.05) in Study 1 and were lighter (4%; P < 0.05) at 24 wk after weaning in Study 2. Carcass measures were similar (P > 0.10) for double- and single-stocked pigs. Double-stocked pigs that were moved at the end of 10 wk had growth performance similar (P > 0.10) to those that remained in the original pen. In summary, double stocking reduced growth rate to 10 wk after weaning but subsequently had no effect on growth rate and improved feed efficiency.  相似文献   

17.
A study was conducted with 20 weaned barrows (14 d, 4.98 +/- 0.21 kg) to determine the effect of feeding spray-dried plasma (SDP) after weaning on the pig's stress response to a lipopolysaccharide (LPS) challenge. After weaning, pigs were fed a diet containing 0 or 7% SDP for 7 d. On d 6 after weaning, all pigs were nonsurgically fitted with a jugular catheter. On d 7 after weaning, the pigs were given i.p. injections of either saline or LPS (150 microg/kg BW) followed by serial blood collection every 15 min for a 3-h period. Following the 3-h blood collection, all pigs were killed and tissue was collected for mRNA analysis. Pig weight on d 7 after weaning was not affected by dietary treatment (P > 0.21). Pigs fed the diet with SDP had lower (P < 0.05) levels of hypothalamic corticotropin-releasing hormone (CRH) mRNA, pituitary gland CRH receptor mRNA, and adrenal gland adrenocorticotropin-releasing hormone (ACTH) receptor mRNA. Dietary treatment did not affect pituitary gland proopiomelanocortin (POMC) mRNA. No effect of LPS treatment was observed in any of the mRNA levels examined. For both serum ACTH and cortisol, there was a significant diet x LPS treatment interaction (P < 0.01) such that both the ACTH and cortisol responses to the LPS challenge were greater in the pigs fed the diet with SDP than in the pigs fed the diet without SDP. For pigs given the saline injection, diet did not affect basal serum cortisol concentration; however, basal serum ACTH concentration was lower in those pigs fed the diet with SDP (P < 0.0001). A diet x LPS treatment interaction (P < 0.024) was observed for adrenal gland mRNA expression for steroidogenic acute regulatory (StAR) protein such that the LPS-induced increase in StAR mRNA was greater in the pigs fed SDP than in pigs fed the diet without SDP. These results demonstrate that pigs fed a diet with SDP have an increased activation of the pituitary-adrenal axis following an LPS challenge compared to pigs fed a diet without SDP.  相似文献   

18.
Kim J  Ha Y  Chae C 《Veterinary pathology》2006,43(5):718-725
This study investigated the potentiation of porcine circovirus 2 (PCV2)-induced postweaning multisystemic wasting syndrome by porcine parvovirus (PPV) and found it was associated with excessive production of tumor necrosis factor-alpha (TNF-alpha). Colostrum-deprived conventional pigs were inoculated intranasally with PCV2 or PPV alone or in combination (PCV2 and PPV). In vitro assay of TNF-alpha, obtained from alveolar macrophages coinfected with PCV2 and PPV, showed a significant increase in TNF-alpha compared to single infection of macrophages with either PCV2 or PPV alone (P < 0.05). All pigs inoculated with PCV2 and PPV developed severe postweaning wasting syndrome, whereas clinical signs (e.g., weight loss) were present but perhaps less severe in either PCV2- or PPV-inoculated pigs. Compared to the pigs inoculated with PCV2 or PPV alone, pigs inoculated dually with PCV2 and PPV showed significantly (P < 0.05) increased levels of TNF-alpha. Levels of TNF-alpha in the sera were reversely correlated with the body weight in pigs experimentally infected with dual inoculation of PCV2 and PPV (r(s) = -0.92, P < 0.001). These data suggest that a potentiation of PPV in PCV2-induced PMWS is associated with the excessive production of TNF-alpha.  相似文献   

19.
The aim of the study was to investigate the effects of dietary linseed (rich in n-3 PUFA) on expression of inflammation-related genes and on growth performance of growing-finishing barrows. Two isoenergetic and isonitrogenous diets were formulated, one as the basal diet and the other containing 10% linseed. Twenty-four Landrace x Yorkshire barrows weighing 35 +/- 3.7 kg were randomly assigned to 1 of 4 treatment groups, with 6 pigs per group. During the entire experimental period of 90 d, these 4 groups of pigs were first fed the basal diet and then fed the linseed diet for 0, 30, 60, and 90 d before slaughter, respectively. Pig growth; messenger RNA (mRNA) expression of peroxisome proliferator-activated receptor-gamma (PPARgamma), IL-1beta0, IL-6, and tumor necrosis factor-alpha (TNF-alpha); and plasma concentrations of the 3 proinflammatory cytokines were measured and analyzed. Average daily feed intake did not differ among treatment groups (P > 0.05), but ADG (P < 0.05) and G:F (P < 0.01) responded quadratically to the duration of linseed diet feeding, and pigs in the 60-d treatment group had the greatest ADG and G:F. The mRNA expression of PPARgamma in loin muscle and spleen increased linearly (P < 0.01) with the duration of linseed diet feeding, whereas its expression in adipose tissue was not affected (P = 0.095). Tumor necrosis factor-alpha and IL-6 mRNA expression in muscle, adipose, and spleen, as well as serum concentration of TNF-alpha, decreased linearly (P < 0.01) with the duration of linseed diet feeding. Peroxisome proliferator-activated receptor-gamma mRNA abundance was negatively correlated with IL-1beta, IL-6, and TNF-alpha mRNA abundance both in muscle (R(2) = 0.63, P < 0.001) and in spleen (R(2) = 0.69, P < 0.001), and PPARgamma mRNA expression in spleen (R(2) = 0.59, P < 0.01) and muscle (R(2) = 0.52, P < 0.05) was negatively correlated with serum TNF-alpha concentration. There were also significant quadratic relations between ADG and expression of PPARgamma (P < 0.05) and splenic TNF-alpha (P < 0.05). These data suggest that intake of n-3 PUFA from the linseed diet led to significant decreases in the expression of proinflammatory cytokine genes, which may stimulate growth in growing-finishing barrows, at least in part, through a PPARgamma-dependent mechanism.  相似文献   

20.
A collaborative study was conducted to evaluate factors related to determining optimal feeding and management programs for increasing net returns from marketing cull sows. A total of 269 multiparous sows averaging 192 kg of body weight were weaned, moved to individual gestation crates, and assigned to one of eight treatment combinations in a 2 x 2 x 2 factorial arrangement for a 42-d postweaning feeding experiment. Factors included limited (L) (1.8 kg/sow/d) or ad libitum (AL) access to feed during wk 1 postweaning, a corn-soybean meal (corn) or barley-sunflower meal (barley) diet, and pregnant or nonpregnant status. All sows were provided ad libitum access to feed from wk 2 to 6 postweaning. Gain and feed intake (FI) data were collected weekly for each sow and used to calculate gain:feed (G/F). Ultrasonic backfat (BF) data were collected on d 0, 21, and 42 postweaning. Sows on the AL treatment had greater FI (P < 0.05) but similar gain (P = 0.80) for the 42-d postweaning period compared to sows on the L treatment. Most of this response was due to lower sow body weight loss during wk 1 postweaning (P < 0.01) when sows were provided AL (-7.2 kg) vs L (-13.2 kg) access to feed. Sows fed the corn diet had higher gain (P < 0.01), improved G/F (P < 0.01), and increased BF (P < 0.01) over the 42-d feeding period than sows fed barley. The corn diet resulted in less sow BW loss (P < 0.01) during wk 1 (-8.8 kg) than the barley diet (-11.6 kg). Pregnant sows had higher gain, FI, G/ F, and BF (P < 0.01) than nonpregnant sows over the 42-d feeding period. Most of this advantage occurred during wk 4 postweaning when FI and gain of nonpregnant sows was lower (P < 0.01) than for pregnant sows. An economic analysis indicated that, when cull sow prices are relatively high and feed prices are moderate to low, maintaining and managing cull sows for an additional 6 wk postweaning may be economically advantageous compared to 0 or 3 wk. Pregnant sows fed the corn diet produced the greatest economic return. These results suggest that mating sows as they return to estrus postweaning and providing ad libitum access to a corn-soybean meal diet improves growth performance and feed efficiency, and may thereby provide increased returns when marketing cull sows.  相似文献   

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