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.     

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.     

Effects of supplementation of beta-glucans on growth performance, nutrient digestibility, and immunity in weanling pigs

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.     

Effects of dietary supplementation of modified zinc oxide on growth performance,nutrient digestibility,blood profiles,fecal microbial shedding and fecal score in weanling pigs

One hundred and forty piglets ((Landrace × Yorkshire) × Duroc, 21 day of age) with an initial weight of 6.50 ± 0.71 kg, were randomly allotted into four treatments to determine the effects of a modified form of zinc oxide (ZnO) on growth performance, nutrient digestibility, blood profiles, fecal microbial shedding and fecal score in weanling pigs. Dietary treatments were: (i) NC, negative control, basal diet containing zinc (Zn) from the premix; (ii) PC, positive control, basal diet containing Zn‐free premix + 3000 ppm ZnO; (iii) H1, basal diet containing Zn‐free premix + 3000 ppm ZnO (phase 1, days 1 to 14)/200 ppm modified ZnO (phase 2, days 15 to 42); (iv) H2, basal diet containing Zn‐free premix + 300 ppm modified ZnO (phase 1)/200 ppm modified ZnO (phase 2). During days 1 to 14, average daily gains (ADG) were higher (P = 0.04) in PC, H1 and H2 groups than that in NC group. Overall, H1 treatment increased the ADG compared with NC (P = 0.05). On day 14, the alkaline phosphatase and plasma Zn concentration were increased (P = 0.01 and 0.04, respectively) in PC, H1 and H2 treatments compared with NC treatment. On days 14 and 42, the fecal Lactobacillus counts in NC group were lowest (P = 0.01, P = 0.04 respectively) among treatments. All supplemented groups showed lower (P = 0.03) fecal score than NC treatment on days 21 and 28. In conclusion, dietary supplementation with modified ZnO increased growth rates and reduced fecal scores in weanling pig. Modified ZnO could be used as a substitute to ZnO as a growth promoter and reduce Zn excretion to the environment because of the lower dosage. [Correction added on 3 February 2015, after first online publication: the initial weight of ‘6.50 ± 1.11 kg’ has been replaced with ‘6.50 ± 0.71 kg’ in the abstract.]     

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 Bacillus subtilis GCB‐13‐001 on growth performance,nutrient digestibility,blood characteristics,faecal microbiota and faecal score in weanling pigs

The present study investigated the influence of Bacillus subtilis GCB‐13‐001 on growth performance, nutrient digestibility, blood characteristics, faecal microbiota and faecal score in weanling pigs. A total of 120 weaning pigs [(Landrace × Yorkshire) × Duroc; 7.73 ± 0.75 kg (28 days of age)] were randomly allotted into three treatments according to their initial body weight (BW) and gender in a 6‐week experiment. There were 8 replication pens in each treatment, with five pigs/pen. Dietary treatment groups were as follows: (a) basal diet (CON), (b) CON + 0.1% Bacillus subtilis GCB‐13‐001 1 × 10⁸ CFU/kg (T1) and (c) CON + 0.1% Bacillus subtilis GCB‐13‐001 1 × 10⁹ CFU/kg (T2). Days 1 to 7, the BW and ADG with T2 treatment were higher (p < .05) than CON treatment, as well as F:G showed trends in linear reduction (p < .1). Days 8 to 21, the BW and ADG were improved (p < .05) in pigs offered T1 and T2 diets compared with CON diet. Days 22 to 42, BW and ADG were higher (p < .05) in pigs fed T2 diet than CON and T1 diets, and the pigs fed T1 diet had higher BW than CON treatment. Overall, the ADG with the T2 treatment was higher (p < .05) than that with the T1 and CON treatments, and pigs offered T1 treatment had higher (p < .05) ADG than CON treatment. Moreover, F:G ratio were significantly decreased (p < .05) by T2 treatment compared with CON treatment. The faecal Lactobacillus counts were improved, and E. coli counts were reduced (p < .05) in pigs fed T2 diet compared with CON at the end of the experiment. In conclusion, supplementation of 0.1% Bacillus subtilis GCB‐13‐001 1 × 10⁹ CFU/kg has shown a beneficial effect in improving BW, increase ADG, decrease F:G ratio.     

Growth performance,nutrient digestibility,and fecal microflora in weanling pigs fed live yeast

Two experiments were conducted to evaluate the effects of live yeast supplementation on nursery pig performance, nutrient digestibility, and fecal microflora and to determine whether live yeast could replace antibiotics and growth-promoting concentrations of Zn and Cu in nursery pigs. In Exp. 1, 156 pigs were weaned at 17 d of age (BW = 5.9 kg) and allotted to a 2 x 2 factorial randomized complete block design (six or seven pigs per pen with six pens per treatment). Factors consisted of 1) dietary supplementation with oat products (oat flour and steam-rolled oats; 0 or 27.7%) and 2) yeast supplementation at 0 or 1.6 x 10(7) cfu of Saccharomyces cerevisiae SC47/g of feed. In Exp. 2, 96 pigs were weaned at 17 d of age and allotted to a 2 x 2 factorial randomized complete block design (four pigs per pen with six pens per treatment) with factors of 1) diet type (positive control containing growth-promoting concentrations of Zn, Cu, and antibiotics or negative control) and 2) live yeast supplementation (0 or 2.4 x 10(7) cfu of Saccharomyces cerevisiae SC47/g of feed). The inclusion of oat products in Exp. 1 decreased (P < 0.10) overall ADG and final BW. Yeast supplementation did not affect growth performance of pigs in Exp. 1 (P = 0.65); however, ADG in Exp. 2 was 10.6% greater (P < 0.01) and ADFI was increased by 9.4% (P < 0.10) in pigs supplemented with yeast in the positive control diet. Addition of Zn, Cu, and antibiotics to the diet improved gain:feed ratio during the prestarter period (P < 0.02) and overall (P = 0.10). In Exp. 1, inclusion of oat products increased (P < 0.01) total bacteria in feces when measured on d 10. Fecal lactobacilli measured on d 28 were reduced (P < 0.05) in pigs fed diets with oat products and yeast (interaction, P < 0.05). In Exp. 2, yeast supplementation decreased (P < 0.05) total bacteria and lactobacilli. Dietary yeast resulted in a greater (P < 0.05) yeast count in feces of pigs during the starter phase of Exp. 1. Yeast decreased (P < 0.10) the digestibility of DM, fat, and GE in the prestarter phase and DM, fat, P, and GE in the starter phase, whereas oat products increased the digestibility of DM, CP, fat, and GE (P < 0.05) in the prestarter phase. Results indicate that live yeast supplementation had a positive effect on nursery pig performance when diets contained growth-promoting antimicrobials. Nonetheless, the response was variable, and the conditions under which a response might be expected need to be further defined.     

Effects of exogenous emulsifiers and fat sources on nutrient digestibility, serum lipids, and growth performance in weanling pigs.

Three experiments were conducted to determine whether emulsifiers improve utilization of fat from diets for early-weaned pigs. In Exp. 1, 96 weanling pigs (17 d old) were used in metabolism cages, with main effects of fat source (soybean oil, tallow, lard, and coconut oil) and emulsifier treatment (no emulsifier, lecithin, and lysolecithin as 10% of the added fat). Soybean oil and coconut oil were more digestible than tallow and lard (P < .001). Tallow was more digestible when lecithin and lysolecithin were added (P < .007), and pigs fed lecithin had lower serum triglycerides and cholesterol than pigs fed lysolecithin (P < .03). In Exp. 2, 270 weanling pigs (21 d old) were used in a growth assay. Treatments were 1) control diet; 2) Diet 1 with soybean oil; 3) Diet 1 with tallow; 4, 5, and 6) Diet 3 with lecithin replacing 5, 10, and 30% of the tallow, respectively; and 7, 8, and 9) Diet 3 with lysolecithin replacing 5, 10, and 30% of the tallow, respectively. At d 14 of the experiment, digestibility of tallow was improved more by lecithin than lysolecithin (P < .008). For the total experiment (d 0 to 35), the control pigs had poorer gain:feed ratio than did the pigs fed the fat sources (P < .002). In Exp. 3, 420 weanling pigs (21 d old) were used. Treatments were 1) control diet with soybean oil; 2) Diet 1 with tallow; and 3, 4, and 5) Diet 2 with 10% of the added fat as soybean oil, lecithin, or monoglyceride, respectively. Adding soybean oil, lecithin, and monoglyceride to tallow increased digestibility of total fat (P < .07). From d 0 to 14, pigs fed soybean oil gained weight faster than pigs fed the other treatments (P < .06), and pigs fed tallow without emulsifiers had the lowest ADG. Considering all experiments, addition of emulsifiers increased digestibility of nutrients but had minimal effect on growth performance.     

营养水平对鲁农2号配套系生长肥育猪生长性能以及养分消化率的影响

为探讨鲁农2号配套系生长肥育猪适宜的能量和粗蛋白质需要量,试验采用单因子随机区组设计,在保持消化能/粗蛋白质比不变的基础上,设为高能量粗蛋白质、中能量粗蛋白质和低能量粗蛋白质3个处理组。选取健康、初始体重（49.58±1.49）kg的鲁农2号配套系生长肥育猪108头（公母各半）随机分3个处理,每个处理4个重复,每个重复（圈）9头猪。试验分为50～80 kg和80～100 kg两个阶段。结果表明,试验全期饲粮营养水平的降低对猪日采食量、日增重和料重比影响不显著,但50～80 kg低营养水平组日增重和粗蛋白质日摄入量显著低于高、中营养水平组。养分表观消化率,50～80 kg以低营养水平组最高,与中营养水平组相比,其干物质、有机物、粗蛋白质和能量的表观消化率分别提高6.97%、8.53%、10.48%和6.45%,差异显著。饲粮营养水平对钙和磷的表观消化率均无显著影响（P〉0.05）。80～100 kg不同营养水平组养分表观消化率差异显著,其中,高营养水平组养分表观消化率最高,其干物质表观消化率分别比中、低营养组提高5.49%和7.17%（P〈0.05）;有机物的表观消化率分别提高4.48%和6.07%（P〈0.05）;钙的表观消化率分别提高32.76%和27.93%（P〈0.05）;磷的表观消化率分别提高38.77%（P〈0.05）和17.44%;粗蛋白质的表观消化率比中营养水平组提高8.56%（P〈0.05）。综合考虑,在50～80 kg阶段,鲁农2号配套系生长猪适宜的消化能为12.98 MJ/kg、粗蛋白质为14.56%;80～100 kg阶段,鲁农2号配套系肥育猪适宜的消化能为12.98 MJ/kg、粗蛋白质为12.40%。     

Effects of rancidity and free fatty acids in choice white grease on growth performance and nutrient digestibility in weanling pigs

Two experiments were conducted to determine the effects of rancidity and FFA in choice white grease (CWG) on growth performance and nutrient digestibility in nursery pigs. In Exp. 1,150 crossbred pigs (average initial BW of 6.8 kg and average initial age of 21 d) were used. Treatments (as-fed basis) were a corn-soybean meal-based control with no added fat, 6% CWG, and 6% CWG heated at 80 degrees C, with oxygen gas bubbled through it at 849 mL/min for 5, 7, 9, or 11 d. Peroxide value for the CWG increased as oxidative exposure was increased from 0 to 7 d (i.e., peroxide values of 1, 40, and 105 mEq/kg for d 0, 5, and 7, respectively), but decreased to 1 mEq/kg as the hydroperoxides decomposed after 9 and 11 d of oxidation. Pigs fed the control diet (no added fat) had the same (P = 0.91) overall ADG (d 0 to 35) but lower G:F (P < 0.04) than pigs fed diets with added fat. As for the effects of fat quality, ADG (linear effect, P < 0.01) and ADFI (linear effect, P < 0.001) decreased as the fat was made more rancid. However, there were no changes in digestibility of fatty acids as the rancidity of the fat was increased (P = 0.16), suggesting that the negative effects of rancidity were from decreased food intake and not decreased nutrient utilization. In Exp. 2, 125 crossbred pigs (average initial BW of 6.2 kg and average initial age of 21 d) were used to determine the effects of FFA in CWG on the growth performance and nutrient digestibility in nursery pigs. Treatments (as-fed basis) were a corn-soybean meal-based control with no added fat, 6% CWG, and 6% CWG that had been treated with 872, 1,752 or 2,248 lipase units/g of fat. The FFA concentrations in the CWG were increased from 2% with no lipase added to 18, 35, and 53% as lipase additions were increased. Pigs fed the control diet (no added fat) had the same (P = 0.30) overall ADG (d 0 to 33) but lower G:F (P < 0.01) than pigs fed diets with added fat. There were no effects of FFA concentration on ADG (P = 0.18), and ADFI increased (linear effect, P < 0.04) as FFA concentration in the CWG increased. Fatty acid digestibility was not affected (P = 0.17) by FFA in the diet. In conclusion, our data suggest that as fat is oxidized (especially to peroxide values greater than 40 mEq/kg), ADG and ADFI in nursery pigs will decrease; however, FFA concentrations of at least 53% do not adversely affect utilization of CWG in nursery pigs.     

Brewers dried yeast as a source of mannan oligosaccharides for weanling pigs

Brewers dried yeast, a source of mannan oligosaccharides (MOS), was assessed as an alternative to an antimicrobial agent (carbadox) for young pigs in two experiments. The yeast contained 5.2% MOS. Agglutination tests confirmed adsorption of several serovars of E. coli and Salmonella spp. onto the yeast product. In Exp. 1, seven replicates (five pigs per pen) of 22-d-old pigs were fed a nonmedicated basal diet or the basal diet with carbadox (55 mg/kg), yeast (3%), or a combination of 3% yeast and 2% citric acid for 28 d. Carbadox did not improve growth performance. Growth rate and feed intake were depressed (P < 0.05) in pigs fed yeast alone or in combination with acid. Log counts of total coliforms, Escherichia coli, and Clostridium perfringens in feces were not affected by diet, but Bifidobacteria spp. counts were lower (P < 0.05) in pigs fed the yeast + acid diet and lactobacilli counts were higher (P < 0.05) in pigs fed yeast. Fecal pH and VFA concentrations and intestinal morphological traits were not consistently affected by diet. Serum IgG levels were elevated in the yeast + acid (P < 0.01) group. In Exp. 2, the effects of yeast and carbadox additions to the diet on enteric microbial populations in young pigs housed in isolation units were evaluated. Pigs (n = 24) were weaned at 11 d of age (4.1 kg BW) and placed in isolation chambers (two pigs per chamber) equipped with individual air filtering systems and excrement containers. Treatments were a nonmedicated basal diet and the basal diet with 55 mg/kg of carbadox or with 3% yeast. Diets were fed for 29 d, then each pig was orally dosed with approximately 9.5 x 10(8) CFU of E. coli K88. Daily fecal E. coli K88 counts were not different (P > 0.05) among treatments, but fecal shedding of carbadox-resistant coliforms was higher (P < 0.01) during the 9-d period in pigs fed carbadox. Total fecal coliforms were consistently lower throughout the postinoculation period in pigs fed yeast (P < 0.05). Yeast reduced colonization oftotal coliforms in the duodenum,jejunum, cecum, and colon, but it did not have a consistent effect on colonization of E. coli K88. Pigs fed yeast tended (P < 0.10) to have higher serum IgG levels than controls. In these experiments, brewers dried yeast and carbadox had minimal effects on growth, microbial populations, and intestinal health traits of early-weaned pigs, but certain serum immunological traits were enhanced by feeding yeast.     

Effect of dietary mannan oligosaccharides and(or) pharmacological additions of copper sulfate on growth performance and immunocompetence of weanling and growing/finishing pigs

Two experiments were conducted to determine the efficacy of mannan oligosaccharides (MOS) fed at two levels of Cu on growth and feed efficiency of weanling and growing-finishing pigs, as well as the effect on the immunocompetence of weanling pigs. In Exp. 1, 216 barrows (6 kg of BW and 18 d of age) were penned in groups of six (9 pens/treatment). Dietary treatments were arranged as a 2 x 2 factorial consisting of two levels of Cu (basal level or 175 ppm supplemental Cu) with and without MOS (0.2%). Diets were fed from d 0 to 38 after weaning. Blood samples were obtained to determine lymphocyte proliferation in vitro. From d 0 to 10, ADG, ADFI, and gain:feed (G:F) increased when MOS was added to diets containing the basal level of Cu, but decreased when MOS was added to diets containing 175 ppm supplemental Cu (interaction, P < 0.01, P < 0.10, and P < 0.05, respectively). Pigs fed diets containing 175 ppm Cu from d 10 to 24 and d 24 to 38 had greater (P < 0.05) ADG and ADFI than those fed the basal level of Cu regardless of MOS addition. Pigs fed diets containing MOS from d 24 to 38 had greater ADG (P < 0.05) and G:F (P < 0.10) than those fed diets devoid of MOS. Lymphocyte proliferation was not altered by dietary treatment. In Exp. 2, 144 pigs were divided into six pigs/pen (six pens/treatment). Dietary treatments were fed throughout the starter (20 to 32 kg BW), grower (32 to 68 kg BW), and finisher (68 to 106 kg BW) phases. Diets consisted of two levels of Cu (basal level or basal diet + 175 ppm in starter and grower diets and 125 ppm in finisher diets) with and without MOS (0.2% in starter, 0.1% in grower, and 0.05% in finisher). Pigs fed supplemental Cu had greater (P < 0.05) ADG and G:F during the starter and grower phases compared to pigs fed the basal level of Cu. During the finisher phase, ADG increased when pigs were fed MOS in diets containing the basal level of Cu, but decreased when MOS was added to diets supplemented with 125 ppm Cu (interaction, P < 0.05). Results from this study indicate the response of weanling pigs fed MOS in phase 1 varied with level of dietary Cu. However, in phase 2 and phase 3, diets containing either MOS or 175 ppm Cu resulted in improved performance. Pharmacological Cu addition improved gain and efficiency during the starter and grower phases in growing-finishing pigs, while ADG response to the addition of MOS during the finisher phase seems to be dependent upon the level of Cu supplementation.     

Effect of group size and feeding regimen on nutrient digestibility studies with weanling pigs

An experiment was conducted to determine the effects of feeding regimen and group size on nutrient (N, Lipid, Ca, P) balance measurements with weanling swine. Treatments imposed were 1) one pig pair-fed to 90% of treatment 3, 2) three pigs pair-fed to 90% of treatment 3 and 3) three pigs with ad libitum access to their diet. A total of 28 barrows weaned at 21 d of age (initial BW 5.9 kg) were allotted by weight and litter in a randomized complete block design with repeated measurements over time to the three treatments in four replicates. The pigs were placed in .6-m x 1.13-m stainless steel metabolism crates and fed the same experimental diet for an initial 4-d adjustment period. This was followed by a 5-d collection of urine and feces with a 2-d interval between collection periods each week of a 4-wk postweaning period. When feed was restricted, N intake, urine N, fecal N and retained N were similar whether pigs were fed as singles or in groups of three. Individually fed pigs had a higher urinary Ca but lower urinary P compared with those fed in groups of three. Lipid and P retention values were similar for individual and group-penned, restricted-fed animals. Pigs provided ad libitum access to feed had greater weight gains and nutrient intakes, excretions (urine, fecal) and retentions (P less than .01) than pigs that were limit-fed. Similar responses among treatments occurred each week of the 4-wk trial. These results suggest that effective weekly balance data can be collected each week sequentially with 21-d weanling pigs penned in groups and allowed to consume feed ad libitum, a situation more similar to natural nursery conditions.     

Effects of beta-mannanase addition to corn-soybean meal diets on growth performance,carcass traits,and nutrient digestibility of weanling and growing-finishing pigs

Four experiments were conducted to determine the effects of adding a beta-mannanase preparation (Hemicell, ChemGen, Gaithersburg, MD) to corn-soybean meal-based diets on growth performance and nutrient digestibility of weanling and growing-finishing pigs. In Exp. 1, 156 weanling pigs (20 d, 6.27 kg BW) were allotted to four dietary treatments in a randomized complete block design. Treatments were a factorial arrangement of diet complexity (complex vs simple) and addition of 3-mannanase preparation (0 vs 0.05%). Pigs were fed in three dietary phases (Phase 1, d 0 to 14; Phase 2, d 14 to 28; and Phase 3, d 28 to 42). Pigs fed complex diets gained faster and were more efficient (P < 0.05) during Phase 1 compared with pigs fed simple diets. Overall, gain:feed ratio (G:F) tended to be improved (P < 0.10) for pigs fed complex diets and it was improved (P < 0.01) for those fed diets with beta-mannanase. In Exp. 2, 117 pigs (44 d, 13.62 kg BW) were allotted randomly to three dietary treatments. Dietary treatments were 1) a corn-soybean meal-based control, 2) the control diet with soybean oil added to increase metabolizable energy (ME) by 100 kcal/kg, and 3) the control diet with 0.05% beta-mannanase preparation. Beta-mannanase or soybean oil improved (P < 0.05) G:F compared with pigs fed the control diet. In Exp. 3, 60 pigs (22.5 kg BW) were allotted randomly to the three dietary treatments used in Exp. 2. Dietary treatments were fed in three phases (23 to 53 kg, 53 to 82 kg, and 82 to 109 kg with 0.95, 0.80, and 0.65% lysine, respectively). Overall, the addition of soybean oil tended to improve G:F (P < 0.10) compared with that of pigs fed the control diet, and G:F was similar (P > 0.54) for pigs fed diets with soybean oil or beta-mannanase. Also, addition of beta-mannanase increased ADG (P < 0.05) compared with that of pigs fed the control or soybean oil diets. There were no differences (P > or = 0.10) in longissimus muscle area or backfat; however, on a fat-free basis, pigs fed the diet with beta-mannanase had greater (P < 0.05) lean gain than pigs fed the control or soybean oil diets. In Exp. 4, 12 barrows (93 kg BW) were allotted randomly to one of the three dietary treatments used in Exp. 3. Addition of 3-mannanase had no effect (P > 0.10) on energy, nitrogen, phosphorus, or dry matter digestibility. These results suggest that beta-mannanase may improve growth performance in weanling and growing-finishing pigs but has minimal effects on nutrient digestibility.     

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…     

Effects of multistrain probiotics on growth performance,nutrient digestibility,blood profiles,faecal microbial shedding,faecal score and noxious gas emission in weaning pigs

This experiment was conducted to investigate the efficacy of multistrain probiotics in weaning pigs. A total of 125 28‐day‐old weaning pigs [(Landrace × Yorkshire) × Duroc] with an initial average body weight (BW) of 7.26 ± 0.76 kg were randomly allotted into 5 treatments, 5 replicate pens/treatment with 5 pigs/pen for 42‐day experiment. Dietary treatments were as follows: CON, basal diet; PC1, CON + 0.01% multistrain probiotics; PC2, CON + 0.03% multistrain probiotics; PC3, CON + 0.06% multistrain probiotics; PC4, CON + 0.1% multistrain probiotics. On day 14, pigs fed the PC4 diet had higher BW gain than pigs fed the CON diet. On day 42, pigs fed multistrain probiotics supplementation diets had higher BW gain than pigs fed the CON diet. From days 1 to 14, pigs fed the PC2, PC3 and PC4 diets had higher (p < 0.05) ADG than pigs fed the CON diet. From day 15 to 42, pigs fed the multistrain probiotics supplementation diets had higher (p < 0.05) average daily gain (ADG) and gain: feed ratio (G:F) than pigs fed the CON diet. In the overall period, pigs fed the multistrain probiotics supplementation diets had higher (p < 0.05) ADG and pigs fed the PC2 and PC4 diets had higher (p < 0.05) G:F than pigs fed the CON diet. On day 42, pigs fed the PC4 diet had higher (p < 0.05) apparent total tract digestibility (ATTD) of dry matter (DM), nitrogen (N) and gross energy (GE), faecal Lactobacillus counts and lower (p < 0.05) E. coli counts and NH₃ emission than pigs fed the CON diet. Pigs fed the multistrain probiotics supplementation diets had lower (p < 0.05) H₂S and total mercaptans emissions than pigs fed the CON diet. Conclusions, dietary supplementation with 0.1% probiotics improved growth performance, nutrition digestibility and intestinal microflora balance and decreased faecal noxious gas emissions in weaning pigs.     

含胆囊收缩素抗体卯黄粉对断奶仔猪生产性能及养分消化率的影响

本试验旨在研究含胆囊收缩素(CCK)抗体卵黄粉对断奶仔猪生产性能、日粮养分消化率及血清CCK浓度的影响.90头(30±2)日龄断奶约克仔猪[平均体重(7.05±0.20)kg]随机分为5个处理,分别饲喂基础日粮和基础日粮中添加100、200、300 mg/kg和400 mg/kg含CCK抗体卵黄粉的试验日粮,每个处理6个重复,每个重复3头仔猪.试验期28 d.结果表明,与基础日粮组相比,添加含CCK抗体卵黄粉可提高仔猪全期平均日增重(ADG)和平均日采食量(ADFI),降低料内比(F/G),其中200 mg/kg组ADG提高12.14%(P＞0.05),ADFI提高6.92%(P＞0.05),F/G降低4.62%(P＞0.05).同时,日粮粗蛋白质消化率随含CCK抗体卵黄粉添加量的增加呈二次曲线变化(P=0.044).添加含CCK抗体卵黄粉后,仔猪血清CCK浓度下降,200 mg/kg组降低35.6%(P＞0.05).综合来看,添加200 mg/kg 含CCK抗体卵黄粉组效果最好.     

不同能量水平日粮对深县猪生长性能、养分消化率和血液生化指标的影响

为了研究不同消化能水平日粮对深县猪生长性能、养分消化率和血液生化指标的影响,选用体重(15. 54±2. 25) kg的健康深县猪48头,随机分成3组,每组4个重复,每个重复4头猪,试验Ⅰ、Ⅱ、Ⅲ组饲粮消化能水平分别为11. 20、11. 70、12. 20 MJ/kg,预试期7 d,正式期28 d。结果显示:试验Ⅲ组的平均日增重显著高于试验Ⅰ组15. 56%(P<0. 05),试验Ⅲ组的料重比(F/G)显著低于试验Ⅰ组(P<0. 05);试验Ⅲ组粗蛋白、总能与粗脂肪表观消化率均显著高于试验Ⅰ组9. 89%、7. 29%、7. 21%(P<0. 05)。综合各项指标,在本试验条件下,生长期深县猪适宜的消化能水平为12. 20 MJ/kg。     

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.     

膨化全脂大豆对仔猪生产性能和养分消化率的影响

根据遗传、性别、体质量等相一致的原则,将30头35日龄断奶的杜洛克仔猪随机分为3组,每组设2个重复,研究膨化全脂大豆对仔猪生产性能和饲粮养分消化率的影响。对照组以玉米豆粕等配制饲粮,试验1组以膨化全脂大豆替代50%的豆粕,试验2组以膨化全脂大豆替代全部豆粕,其他饲粮组成保持不变,进行40d的饲养试验。在试验第20天开始,连续收集粪便3d,测定饲粮养分消化率。结果表明,试验1组日增重比对照组提高了17.6%,差异显著(P<0.05),试验2组比对照组提高了7.4%(P>0.05);试验1组和试验2组饲料利用率分别比对照组提高11.7%和7.6%。试验2组干物质消化率显著高于对照组(P<0.05),蛋白质的消化率3组基本接近,但含有膨化大豆的试验1组和试验2组的粗脂肪和粗灰分的消化率均比对照组有提高趋势。