微囊丁酸钠对母猪生产性能与仔猪生长性能的影响

40头妊娠85 d健康二元杂交经产母猪(胎次、体况、前胎产仔数一致),随机分为2组,每组20个重复,每个重复1头,分别为对照组(基础日粮)、处理组(妊娠期:基础日粮+800 g/t微囊丁酸钠;哺乳期:基础日粮+500 g/t微囊丁酸钠)。结果表明,饲粮中添加微囊丁酸钠能够显著提高母猪生产后期采食量(4.56%),显著降低母猪哺乳期的体失重(P<0.05),提高仔猪断奶日增重(P<0.05)和断奶体重。此外,处理组弱仔率较对照组下降35.72%,窝断奶仔猪数和断奶仔猪均重有上升趋势(P=0.07,P=0.14)。由此可见,微囊丁酸钠可改善母猪生产性能,提高仔猪平均日增重。     

Effects of sodium butyrate on growth performance,haematological and immunological characteristics of weanling piglets

The experiment was conducted to study the effects of sodium butyrate (SB) on growth, haematological and immunological characteristics in weanling pigs. A total of 100 male piglets (Duroc×Landrace×Yorkshire) with a body weight of 8.0 ± 0.2 kg weaned at the age of 28 days were randomly assigned to two treatments with five replicates and 10 pigs per replicate. Piglets received a basal diet (control group) or diets supplemented with 1000 mg/kg SB. The feeding trial lasted for 21 days. The results showed that dietary SB significantly decreased (p < 0.05) diarrhoea incidence of weaned piglets, but did not affect (p > 0.05) the average daily feed intake (ADFI), average daily gain (ADG) and feed to gain (F/G). Furthermore, piglets fed dietary SB had higher (p < 0.05) serum concentrations of glucose and triglycerides and lower (p < 0.05) serum concentrations of urea nitrogen, cortisol, D‐lactic acid and diamine oxidase when compared with the control group. However, dietary SB did not affect concentrations of serum albumin, total protein, insulin and glucagon (p > 0.05). There were no significant (p > 0.05) treatment effects on serum IgA and IgM, whereas serum IgG concentration and IgA+ cell count in jejunum from pigs fed SB were significantly higher (p < 0.05) than in those given the basal diet. In conclusion, the present study indicated that dietary SB significantly decreased diarrhoea incidence of weaned piglets and increased the efficiency of nitrogen utilization. Also, dietary SB could regulate and enhance the immune function of piglets by increasing the serum IgG concentration and IgA+ cell count in jejunum. Our results suggest that SB may reduce some of the adverse effects of weaning stress and play an important role in maintaining the integrity of intestinal mucosa.     

Effect of mannan oligosaccharides on growth performance of weanling pigs

Four experiments were conducted to evaluate the effects of mannan oligosaccharides (provided by Bio-Mos [BM], a product containing a minimum of 28% glucomannoprotein from S. cerevisiae) on growth performance of nursery pigs. Treatments were replicated with five to six pens of four to five pigs each. Initial BW ranged from 4.7 to 5.4 kg, and pigs were weaned at 16 to 20 d of age. Experiments 1, 2, and 4 consisted of Phase 1 (7 to 8 d), Phase 2 (12 to 14 d), and Phase 3 (7 to 8 d) periods, but Exp. 3 consisted only of Phase 1 (7 d) and 2 (14 d) periods. The diets for Phase 1, 2, and 3 contained 1.6, 1.5, and 1.1% Lys, respectively. The treatments in Exp. 1 were 0, 0.20, and 0.30% BM, which did not affect growth performance. The treatments in Exp. 2 were two levels of excess Zn (0 and 3,000 ppm) and three levels of BM (0, 0.20, and 0.30%) in a 2 x 3 factorial. Excess Zn increased (P < 0.08) ADG and ADFI in Phase 2 and 3 and overall. The 0.20% BM addition increased ADG (Phase 3 and overall) and ADFI (Phase 2 and overall) in the absence of excess Zn but did not affect or decreased these response variables in the presence of excess Zn (Zn x BM quadratic, P < 0.08). Experiment 3 was similar to Exp. 2, but the 0.30% BM addition was not used. Excess Zn decreased (P < 0.09) ADG in Phase 1 but increased (P < 0.09) ADG and ADFI in Phase 2. The BM decreased (P < 0.03) overall ADFI but increased Phase 2 and overall ADG and gain:feed (GF) in the absence of excess Zn but not in the presence of excess Zn (Zn x BM, P < 0.07). The BM decreased ADFI during Phase 2, but the decrease was greater in pigs fed excess Zn (Zn x BM, P < 0.07). Experiment 4 evaluated the interactive effects of the antibiotic (oxytetracycline and neomycin) and BM and of Zn and BM. Antibiotic (no excess Zn) increased (P < 0.01) ADG and ADFI in Phases 2 and 3 and overall. The BM addition decreased ADG and GF in Phase 2 when the antibiotic was not in the diet but increased ADG when the antibiotic was in the diet (antibiotic x BM, P < 0.05). Excess Zn increased (P < 0.07) ADG and ADFI during Phases 2 and 3 and overall. In Phase 2, the 0.20% BM decreased GF when excess Zn was not added to the diet but increased GF when Zn was included (Zn x BM, P < 0.03). Mannan oligosaccharides improved pig performance in some instances during Phase 2 when fed in combination with an antibiotic and no excess dietary Zn, but it had no effect or negative effects in the presence of excess Zn or in the absence of an antibiotic.     

丁酸钠对断奶仔猪生产性能的影响

选用24日龄断奶仔猪45头,随机分为3组,每组3个重复,每重复5头仔猪。对照组饲喂基础日粮,2个试验组在基础日粮中分别添加0.05%和0.1%的丁酸钠,试验期为26d。试验结果表明:与对照组相比,试验组日增重分别提高8.01%和17.84%;腹泻率分别下降69.4%和75.0%;每头仔猪毛利收入分别提高15.39%和33.1%。试验表明,丁酸钠对断奶仔猪的生长有良好的促进作用。     

纳米氧化锌对断奶仔猪生长性能的影响

选用63头断奶仔猪,分为处理1组(3000mg/kg普通饲料级氧化锌)、处理2组(250mg/kg纳米氧化锌)、处理3组(500mg/kg纳米氧化锌)三个处理,每个处理3个重复,每个重复7头仔猪,试验期20d。结果表明:纳米氧化锌(500mg/kg)能显著提高断奶仔猪的日增重(与处理1组相比,提高9.91%),改善肉料比,有较好的经济效益。     

Performance, intestinal microflora, and wall morphology of weanling pigs fed sodium butyrate

Adding organic acids to piglet diets is known to be helpful in overcoming postweaning syndrome, and butyric acid is known to be the main energy source for the epithelial cells of the large intestine and the terminal ileum. This study investigated the effect of sodium butyrate (SB) on in vitro and in vivo swine microflora, piglet growth performance, and intestinal wall morphology. During a 24-h in vitro cecal fermentation, total gas production and maximal rate of gas production were reduced linearly by SB (P < 0.001). Ammonia in cecal liquor was increased linearly by SB after 4, 8, and 24 h of fermentation (P < 0.001). In the in vivo study, 48 piglets housed in individual crates were allotted to 4 treatment groups (12 animals per treatment) for 6 wk. Piglets received a basal diet with a) no addition (control), or with SB at b) 1,000 ppm, c) 2,000 ppm, or d) 4,000 ppm. After 6 wk, 6 animals per treatment were killed, and samples of intestinal content and mucosa were collected. Sodium butyrate did not improve the animal growth performance. In the cecum, SB increased pH and isobutyric acid concentration (linear, P < 0.05) and tended to increase ammonia concentration (P = 0.056). Intestinal counts of clostridia, enterobacteriaceae, and lactic acid bacteria as well as intestinal mucosal morphology were not affected by feeding SB. This study showed that SB influenced the cecal microflora in an in vitro system, reducing the total gas production but increasing ammonia concentrations. When fed to piglets, SB did not improve the animal growth performance, increased cecal pH, and tended to increase cecal ammonia concentrations. Further studies will be needed to better understand the mechanisms underlying the effects observed when SB is fed to piglets.     

Effect of salmon protein hydrolysate and spray-dried plasma protein on growth performance of weanling pigs

Two experiments, each consisting of 2 trials, were conducted to determine the effect of salmon protein hydrolysate (SPH) and spray-dried plasma protein (SDPP) fed during the first week postweaning and their subsequent effect on the growth performance of weanling pigs. Pigs were fed in a 3-phase feeding program with durations of 7 d for phase 1 in both Exp. 1 and 2; 14 or 15 d for phase 2 in Exp. 1 and 2, respectively; and 7 or 8 d for phase 3 in Exp. 1 and 2, respectively. Dietary treatments were fed only during phase 1, whereas the same diet was fed to all pigs in phases 2 and 3. Pigs were blocked by initial BW and sex, and littermates were balanced across treatments. Data from the 2 trials within each experiment were combined and analyzed together; no treatment × trial interactions (P > 0.10) were observed. In Exp. 1, a total of 324 weanling pigs (10 replications of 5 or 6 pigs per pen) with an average initial BW of 6.4 ± 1.3 kg were assigned to 1) a control diet with no SPH or SDPP, 2) 1.5% SPH, 3) 3.0% SPH, 4) 1.5% SDPP, 5) 3.0% SDPP, or 6) 1.5% SPH + 1.5% SDPP. Experiment 2 was similar to Exp. 1, but red blood cells were removed from all diets to reduce diet complexity. In Exp. 2, weanling pigs (n = 320, 14 replications of 5 or 6 pigs per pen) with an average initial BW of 5.4 ± 1.2 kg were assigned to 1) a control diet with no SPH or SDPP, 2) 1.5% SPH, 3) 1.5% SDPP, or 4) 1.5% SPH + 1.5% SDPP. Three batches of SPH were used, and each batch was analyzed for AA composition. In Exp. 1, the inclusion of SDPP or SPH during phase 1 did not affect (P > 0.10) ADG, ADFI, or G:F compared with those of pigs fed the control diet. No carryover effects on growth performance were observed in any of the subsequent phases. Overall, G:F was greater (P = 0.08) in pigs fed the 1.5% diets compared with those fed the 3.0% diets. In Exp. 2, no differences (P > 0.10) were observed in ADG, ADFI, or G:F among pigs fed the SPH or SDPP diets compared with those of pigs fed the control diet. Pigs fed the combined diet had greater (P < 0.10) overall ADFI compared with that of pigs fed the control diet, but ADFI was similar to that of pigs fed the SPH and SDPP diets. These results indicate that inclusion of up to 3% SDPP or SPH in diets fed during the first week postweaning did not affect the growth performance of weanling pigs, and no subsequent carryover effects were observed. Salmon protein hydrolysate did not affect the growth performance of weanling pigs and may be considered an alternative protein source in diets for weanling pigs.     

Effects of increasing dietary L-carnitine on growth performance of weanling pigs

Four experiments were conducted to evaluate the effects of supplementing graded levels (0 to 100 ppm) of L-carnitine to the diet of weanling pigs on growth performance during a 34- to 38-d experimental period. A fifth experiment was conducted to determine the effects of addition of L-carnitine to diets with or without added soybean oil (SBO) on growth performance. In Exp. 1, 128 pigs (initial BW = 5.5 kg) were allotted to four dietary treatments (six pens per treatment of four to six pigs per pen). Dietary treatments were a control diet containing no added L-carnitine and the control diet with 25, 50, or 100 ppm of added L-carnitine. In Exp. 2, 3, and 4, pigs (4.8 to 5.6 kg of BW) were allotted to five dietary treatments consisting of either a control diet containing no added L-carnitine or the control diet with 25, 50, 75, or 100 ppm of added L-carnitine. All diets in Exp. 1 to 4 contained added soybean oil (4 to 6%). There were seven pens per treatment (four to five pigs per pen) in Exp. 2, whereas Exp. 3 and 4 had five and six pens/treatment (eight pigs per pen), respectively. In general, dietary carnitine additions had only minor effects on growth performance during Phases 1 and 3; however, dietary L-carnitine increased (linear [Exp. 1], quadratic [Exp. 2 to 4], P < 0.03) ADG and gain:feed (G:F) during Phase 2. The improvements in growth performance during Phase 2 were of great enough magnitude that carnitine addition tended to increase ADG (linear, P < 0.10) and improve G:F (quadratic, P < 0.02) for the entire 38-d period. In Exp. 5, 216 weanling pigs (5.8 kg of BW) were allotted (12 pens/treatment of four to five pigs per pen) to four dietary treatments. The four dietary treatments were arranged in a 2 x 2 factorial with main effects of added SBO (0 or 5%) and added L-carnitine (0 or 50 ppm). Pigs fed SBO tended (P < 0.07) to grow more slowly and consumed less feed compared with those not fed SBO, but G:F was improved (P < 0.02). The addition of L-carnitine did not affect (P > 0.10) ADG or ADFI; however, it improved (P < 0.03) G:F. Also, the increase in G:F associated with L-carnitine tended to be more pronounced for pigs fed SBO than those not fed SBO (carnitine x SBO, P < 0.10). These results suggest that the addition of 50 to 100 ppm of added L-carnitine to the diet improved growth performance of weanling pigs. In addition, supplemental L-carnitine tended to be more effective when SBO was provided in the diet.     

氧化锌和硫酸锌对仔猪断奶后腹泻率和生长的影响

１材料与方法１ .１试验材料氧化锌 (ＺｎＯ)由浙江大学饲料所提供 ,硫酸锌(ＺｎＳＯ４·７Ｈ２Ｏ)由河南省潢川市亚美饲料厂提供 ;试验动物为河南亚美养殖场一厂的杜长大三元杂交仔猪 ;试验饲粮参照美国ＮＲＣ(１９８８版 )营养需要配合而成的粉状全价饲料 ,基础配方和营养水平见表１。１．２饲养试验９０头杜长大三元杂交仔猪 ,按饲养试验要求分成３组 ,每组设３个重复 ,每个重复１０头 (公母各半 )。其中一组饲喂含３０００ｍｇ／ｋｇ硫酸锌饲粮 ,另二组分别饲喂１００ｍｇ／ｋｇ 氧化锌 (对照组 )和３０００ｍｇ／ｋｇ 的氧化锌饲粮。上…     

Dietary supplementation with cellooligosaccharide improves growth performance in weanling pigs

Nondigestible oligosaccharides are not digested in the small intestine, but are fermented by bacteria colonizing in the large intestine. Physiological effects of non‐digestible oligosaccharides have been considered to be conferred by the fermentation of bacteria colonizing in the large intestine. Because cellooligosaccharide is a non‐digestible oligosaccharide, various physiological effects are expected. However, physiological functions of cellooligosaccharide are not well understood. This experiment was conducted to clarify the effect of dietary supplementation with cellooligosaccharide on the growth performance in weanling pigs. The result showed that average daily gain was significantly higher (P < 0.05) in pigs fed a diet supplemented with cellooligosaccharide than in pigs without cellooligosaccharide. There was a tendency to increasing average daily feed intake in pigs with cellooligosaccharide, though the significant difference was not detected (P = 0.18). Feed efficiency and nutrient digestibility of feces and ileum were not changed by feeding cellooligosaccharide. In addition, blood urea nitrogen was significantly higher (P < 0.05) in pigs fed the diet supplemented with cellooligosaccharide than in pigs without cellooligosaccharide. The concentrations of acetic and iso‐valeric acids in the cecum of pigs fed the diet with cellooligosaccharide tended to be higher (P < 0.10) than those without cellooligosaccharide. The results obtained in this study demonstrated that dietary supplementation with cellooligosaccharide improves growth performance in weanling pigs.     

包被型丁酸钠对猪生产性能和肠道形态的影响

本研究对包被型丁酸盐对生长猪的生产性能、肠道内容物组成以及肠道形态的作用进行了检验,目的旨在评估包被型丁酸盐(Butirex C4)对肠道参数、猪生长性能和饲料转化率的影响。结果表明饲喂Butirex C4能够有效地提高猪的生产性能,促进肠道发育和肠绒毛生长,使肠道更健康。     

植物提取物对断奶仔猪生产性能和经济效益的影响

为考察植物提取物的应用效果,选择100头28日龄平均体重7.34＋0．11kg的长×大断奶仔猪,按性别、体重、品种一致的原则随机分成4个处理,每个处理5个重复,每个重复5头仔猪。分别饲喂添加15mg／kg阿维拉霉素＋250mg／kg氧化锌、40mg／kg吉它霉素＋7．5mg／kg黄霉素、400mg／kg诺必达、300mg／kg植物提取物。结果表明：在试验全期中．4个处理组在平均日采食量和平均日增重上无显著性差异（P〉0．05）;在料肉比方面,黄霉素＋吉它霉素组显著高于其他各组（P〈0．05）,其他各组之间差异不显著（P〉0.05）;腹泻次数以阿维拉霉素＋氧化锌组和植物提取物组最少（P〈0．05）,其他各组差异不明显（P〉0.05）。在经济效益方面。阿维拉霉素＋氧化锌组最好,其次为植物提取物组。     

Effects of chitooligosaccharide supplementation on growth performance, nutrient digestibility, blood characteristics and immune responses after lipopolysaccharide challenge in weanling pigs

The objective of this study was to determine the effects of dietary supplementation with chitooligosaccharide (COS) on growth performance, nutrient digestibility, blood characteristics and immune response in lipopolysaccharide-challenged weanling pigs. A total of 90 crossbred weanling pigs (5.44 ± 0.50 kg BW) were employed in Exp. 1. The three dietary treatments were basal diets supplemented with 0, 2.5, and 5 g COS/kg, and fed for 28 d. Each treatment had 6 replications with 5 pigs per pen. Increasing the level of supplemental COS tended to linearly (P < 0.10) improve ADG and ADFI during phase 2 and overall period, while there were no differences in G:F. The linear improvement in the apparent DM (P < 0.05) and N (P < 0.10) digestibility in pigs fed COS supplemented diets was noticed. The tested blood characteristics were not influenced under non-challenge conditions. In Exp. 2, a total of 20 pigs (5.22 ± 0.31 kg BW) were initially assigned to two dietary treatments and fed basal diets supplemented with 0 or 0.5 g COS/kg for 28 d. At the end of d 28, half of the pigs in each treatment (n = 5) were injected i.p. with Escherichia coli lipopolysaccharide at a concentration of 100 μg/kg of BW. The other half of the pigs in each treatment were injected with sterile saline solution at a concentration of 100 μg/kg of BW. This arrangement resulted in a 2 × 2 factorial design with diet and LPS challenge as the main effects. Blood sample and rectal temperature data were collected at 0, 2, 4 and 12 h post-challenge. Rectal temperatures increased as the result of LPS injection at 4 and 12 h post-challenge (P < 0.05). Serum cortisol, IGF-1, and TNF-α concentration were also increased as the result of LPS challenge (P < 0.05). The COS treatments resulted in lower cortisol concentrations at 2 h and higher IGF-1 concentrations at 4 h post-challenge (P < 0.05). COS and LPS interactions were also observed on cortisol and IGF-1 when the COS effects were presented (P < 0.05). Haptoglobin concentrations remained unaffected throughout the challenge period. White blood cell counts were increased in the LPS-treated pigs at 2 and 4 h post-challenge (P < 0.01). Lymphocyte count was elevated at 2 h and reduced at 12 h post-challenge as the result of LPS challenge (P < 0.05). However, there were no COS main effects observed on lymphocyte count throughout the challenge period. The comparison between two LPS challenged treatments also indicated that COS treatment has beneficial effects on rectal temperature, cortisol and IGF-1 concentrations. In conclusion, dietary supplementation with COS had little effect on nutrient digestibility and inflammatory stress markers in weanling pigs.     

Influence of sodium diethyldithiocarbamate (Imuthiol) on lymphocyte function and growth in weanling pigs

Mitogen-stimulated lymphocyte proliferation, delayed-type hypersensitivity (DTH) reactions, interleukin-2 (IL-2) production, and growth performance were evaluated in 3-week-old pigs treated with imuthiol. Lymphocyte proliferative responses to Con A and PWM were reduced (P < 0.05) in pigs treated with imuthiol at 25 mg/kg; PHA proliferative responses were not influenced by imuthiol treatment. Imuthiol at 2.5 mg/kg and 25 mg/kg lowered IL-2 production when compared to saline-treated controls. Delayed-type hypersensitivity responses to PHA were higher in 25 mg/kg imuthiol-treated pigs; however, 2.5 mg/kg imuthiol-treated pigs had lower DHT reactions. Imuthiol at 2.5 mg/kg and 25 mg/kg reduced (P < 0.05) average daily feed intake. These data suggest that in vivo imuthiol treatment in pigs lowers lymphocyte proliferative responses, IL-2 production, and growth performance.     

Effect of corn distillers dried grains with solubles on growth performance and health status indicators in weanling pigs

Two experiments were conducted to evaluate effects of corn distillers dried grains with solubles (DDGS) on growth performance and health status of weanling pigs. Experiment 1 evaluated effects of increasing concentrations of DDGS on growth performance and health of weanling pigs. Dietary treatments included 1) control (CTL), 2) 0% DDGS (0% DDGS in phase 2 and 30% DDGS in phase 3), 3) 5% DDGS (5% DDGS in phase 2 and 30% DDGS in phase 3), and 4) 30% DDGS (phases 2 and 3). Overall, pigs fed 30% DDGS during phases 2 and 3 had decreased (22.1 vs. 25.1 and 24.0 kg; P = 0.003) BW compared with CTL pigs and pigs that only received DDGS during phase 3. In addition, pigs fed 5 or 30% DDGS in phase 2 had decreased (422.7 or 390.0 vs. 468.2 g; P = 0.003) ADG compared with CTL pigs. However, pigs fed 0% DDGS during phase 2 had similar BW, ADG, and ADFI compared with CTL pigs. Experiment 2 was conducted to evaluate effects of DDGS, lactose, and their interaction on growth performance and health of weanling pigs. Dietary treatments included 1) CTL, 2) lactose (20%), 3) DDGS (15%), and 4) lactose + DDGS. Diets of interest were fed during phase 1 (d 0 to 14), and a common diet was fed during phase 2 (d 14 to 28). Pigs receiving DDGS in phase 1 had greater ADG (576.2 vs. 534.6 g; P = 0.01) and ADFI (814.9 vs. 751.6 g; P = 0.01) during phase 2 compared with non-DDGS-fed pigs. Pigs receiving lactose during phase 1 had greater ADG (214.7 vs. 177.2 g; P = 0.01) and G:F (741.0 vs. 660.3 g/kg; P = 0.01) and tended to have greater ADFI (289.3 vs. 267.6 g; P = 0.07) during phase 1 but decreased (537.7 vs. 573.1 g; P = 0.09) ADG during phase 2. Serum immunoglobulin analyses and fecal microbial profiling were conducted in both experiments as indicators of health status. No effects of dietary treatment were observed for serum immunoglobulin in either experiment. Fecal microbial profiling resulted in statistically significant effects of dietary treatment with respect to microbial similarity and diversity indices (Exp. 1) and lactic acid-producing bacteria (Exp. 2), where main effects of both lactose and DDGS were observed with respect to putative Lactobacillus reuteri (P < 0.05). Results from Exp. 1 indicate that decreased concentrations of DDGS early in the nursery phase may negatively affect growth performance; however, growth performance may be maintained when inclusion of high concentrations (30%) of DDGS is delayed until the late nursery period. Results from Exp. 2 indicate that lactose may be incorporated in nursery diets containing DDGS to help maintain growth performance, and DDGS and lactose may affect fecal microbial profiles.     

Effect of δ-aminolevulinic acid on growth performance, nutrient digestibility, blood parameters and the immune response of weanling pigs challenged with Escherichia coli lipopolysaccharide

This study investigated the effects of dietary δ-aminolevulinic acid (ALA) on growth performance, nutrient digestibility, blood parameters and whether ALA improved the immune response of weanling pigs challenged with Escherichia coli lipopolysaccharide (LPS). Eighty pigs (body weight = 7.21 ± 0.51 kg) were allotted to four dietary treatments, with four pens per treatment and five pigs per pen. Basal diets were supplemented with 0, 5, 10, and 15 mg/kg ALA (as-fed basis) and fed for 35 days. At the end of the feeding period, 10 pigs were selected from both the 0- and 10-mg/kg ALA treatment groups; five were injected i.p. with LPS (50 μg/kg BW) and the other five pigs with an equivalent amount of sterile saline, resulting a 2 × 2 factorial arrangement. Blood sample and rectal temperature data were collected at 0, 2, 4 and 12 h after challenge. Growth performance was not affected by dietary treatments over the total experimental period. However, dry matter (DM) and nitrogen (N) digestibility was improved in the 15-mg/kg ALA treatment group at day 35 (P < 0.05). Serum hemoglobin (Hb) and iron levels were also increased, with the 10-mg/kg ALA treatment showing the highest concentration (P < 0.05). On day 35, red (RBC) and white blood cell (WBC) counts were elevated, with the 5- and 10-mg/kg ALA treatments having the highest counts (P < 0.05). During challenge, LPS injection elevated rectal temperature at 2 and 4 h postchallenge (P < 0.05). Plasma cortisol concentration was also increased by LPS injection at 2 and 4 h postchallenge and an ALA-alleviating effect was evident at 2 h postchallenge (P < 0.01). Concentration of plasma insulin-like growth factor-I (IGF-I) was increased in the ALA-supplemented treatments at 2 h postchallenge (P < 0.05). LPS injection increased plasma tumor necrosis factor-α (TNF-α) concentrations at 2, 4 and 12 h (P < 0.01), while an ALA-alleviating effect was observed at 2 and 4 h postchallenge (P < 0.05 and P < 0.10, respectively). Challenge with LPS decreased WBC counts at 2 and 4 h postchallenge (P < 0.01). At 12 h postchallenge, RBC, WBC and lymphocyte counts were affected by LPS challenge, while an ALA effect was only observed on WBC count (P < 0.05). In conclusion, dietary supplementation of ALA in weanling pigs can improve DM and N digestibilities, and iron status and have a beneficial effect on the immune response during inflammatory challenge.     

Effect of medium-chain triglycerides on growth performance,nutrient digestibility,plasma metabolites and antioxidant capacity in weanling pigs

The aim of this study was to investigate the effect of medium-chain triglycerides(MCTs) on growth performance, nutrient digestibility, plasma metabolites and antioxidant capacity in weanling pigs. A total of 160 weanling(Duroc × Landrace x Yorkshire) pigs(age: 21 ± 1 d; body weight: 7.50 ± 0.28 kg) were randomly allotted to 4 treatments, receiving the following diets for 28 d: control diet [containing 3.5%soybean oil(SO)], MCT1 diet(containing 0.7% MCTs and 2.8% SO), MCT2 diet(containing 1.4% MCTs and2.1% SO) and MCT3 diet(containing 2.1% MCTs and 1.4% SO). Dietary inclusion of MCTs improved the average daily gain and feed efficiency(FE) of pigs compared with the control during the first 2 weeks post-weaning(P 0.05). A similar positive effect was also observed for the overall FE in MCT2 group(P 0.05). Compared with the control, apparent total tract digestibility(ATTD) of ether extract was improved by MCT2 and MCT3 treatment from day 12-14 post-weaning(P 0.05). In addition, MCT2 treatment also exerted a beneficial effect on the ATTD of dry matter(P 0.05). The increased total protein concentration and decreased urea nitrogen and malondialdehyde levels of plasma were observed in both MCT2 and MCT3 groups on day 14 post-weaning(P 0.05). In conclusion, MCTs could improve growth performance, nutrients utilization, and antioxidant ability of weanling piglets.     

Effect of CLA on performance and immune response of weanling piglets

An experiment was conducted to evaluate the effect of CLA on the immune response and performance of piglets when subjected to an immune challenge. A total of 32 weanling pigs (17 to 23 d of age) with an initial BW of 8.9 kg were allotted to a 3 × 2 factorial arrangement of treatments. There were 3 levels of dietary CLA (0%, 1%, and 2%) and 2 levels of lipopolysaccharide (LPS) challenge (unchallenged and challenged). Challenged pigs were challenged on d 7 and 21. On d 4 and 18, all pigs were inoculated with BSA for assessment of IgG production. There was no difference in growth performance among piglets receiving different CLA supplementation levels. However, LPS-challenged piglets had poorer BW (P < 0.05), ADFI (P < 0.01), and ADG (P < 0.001) compared with the control group at d 35 postweaning. Lipopolysaccharide-challenged piglets also had increased respiratory rate (P < 0.001) and rectal temperature (P < 0.001), and decreased plasma proteins, hematocrit, and white blood cell counts (P < 0.05). Production of IgG against BSA was increased in the 1% CLA supplementation group (P < 0.001), indicating that CLA has an immunomodulatory effect. Supplementation with CLA did not affect lymphocyte proliferation, percentage of CD4(+) and CD8(+) cells, plasma proteins, red and white blood cell count, respiratory rate, or rectal temperature after LPS challenge. Although CLA supplementation did not influence growth performance or certain immune system measurements, the increased IgG titers with 1% CLA dietary supplementation indicate that it has a beneficial effect on the humoral immune system of weaned piglets.     

Effects of organic forms of zinc on growth performance,tissue zinc distribution,and immune response of weanling pigs

This study was conducted to determine the effect of zinc level and source on growth performance, tissue Zn concentrations, intracellular distribution of Zn, and immune response in weanling pigs. Ninety-six 3-wk-old crossbred weanling pigs (BW = 6.45 +/- 0.17 kg) were assigned to one of six dietary treatments (four pigs per pen, four replicates per treatment) based on weight and litter origin. Treatments consisted of the following: 1) a corn-soybean meal-whey diet (1.2% lysine) with a basal level of 80 ppm of supplemental Zn from ZnSO4 (control; contained 104 ppm total Zn); 2) control + 80 ppm added Zn from ZnSO4; 3) control + 80 ppm added Zn from Zn methionine (ZnMet); 4) control + 80 ppm added Zn from Zn lysine (ZnLys); 5) control + 40 ppm added Zn from ZnMet and 40 ppm added Zn from ZnLys (ZnML); and 6) control + 160 ppm added Zn from ZnSO4. Zinc supplementation of the control diet had no effect on ADG or ADFI. Gain efficiency was less (P < 0.05) for pigs fed 80 ppm of Zn from ZnSO4 than for control pigs and pigs fed 160 ppm of Zn from ZnSO4. Organ weights, Zn concentration, and intracellular distribution of Zn in the liver, pancreas, and spleen were not affected (P = 0.12) by Zn level or source. Skin thickness response to phytohemagglutinin (PHA) was not affected (P = 0.53) by dietary treatment. Lymphocyte proliferation in response to PHA was greater (P < 0.05) in pigs fed ZnLys than in pigs fed the control diet or the ZnML diet; however, when pokeweed mitogen was used, lymphocyte proliferation was greatest (P < 0.05) in pigs fed the ZnMet diet than pigs fed the control, ZnLys, ZnML, or 160 ppm ZnSO4 diets. Antibody response to sheep red blood cells was not affected by dietary treatments. Supplementation of 80 ppm of Zn from ZnSO4 or ZnMet and 160 ppm of Zn from ZnSO4 decreased (P < 0.05) the antibody response to ovalbumin on d 7 compared with control pigs, but not on d 14. Phagocytic capability of peritoneal exudate cells was increased (P < 0.05) when 160 ppm of Zn from ZnSO4 was supplemented to the diet. The number of red blood cells ingested per phagocytic cell was increased (P < 0.05) in pigs fed the diet supplemented with a combination of ZnMet and ZnLys and the diet with 160 ppm of Zn from ZnSO4. Results suggest that the level of Zn recommended by NRC for weanling pigs was sufficient for optimal growth performance and immune responses, although macrophage function may be enhanced at greater levels of Zn. Source of Zn did not alter these measurements.     

包膜丁酸钠对青脚麻种鸡生产性能的影响

试验研究包膜丁酸钠对青脚麻种鸡生产性能的影响,为包膜丁酸钠在种鸡上的应用提供理论参考。将11 000只27周龄健康的青脚麻种鸡随机分为2个处理,每个处理5个重复,每个重复1 100只,分别为对照组(基础日粮)和试验组(基础日粮+500 mg/kg包膜丁酸钠)。试验期为60 d。试验结果表明,与对照组相比,包膜丁酸钠组蛋鸡产蛋率提高2.76%,差异显著(P<0.05),高峰产蛋率提高6.28%,差异显著(P<0.05),种蛋合格率提高3.16%,差异显著(P<0.05),死淘率降低49.28%,差异显著(P<0.05)。由此可见,包膜丁酸钠可改善青脚麻种鸡的生产性能。