Effects of sweeteners on individual feed intake characteristics and performance in group-housed weanling pigs

To assess the effects of 2 high intensity sodium saccharine-based sweeteners on individual feed intake characteristics and performance of group-housed weaned pigs, one hundred ninety-eight 26-d-old weanling pigs were given ad libitum access to 3 dietary treatments containing: no additional sweetener (control), 150 mg of sweetener (Sucram C-150)/kg, or 150 mg of sweetener (Sucram 3D)/kg. At weaning, piglets were allocated to 18 pens (11 pigs/pen) based on BW, sex, and ancestry, and pens were randomly assigned to 3 treatments with 6 pens per treatment. The pens were equipped with computerized feeding stations. During the first 12 d, pigs were offered pelleted prestarter diets that were replaced at once by pelleted starter diets for the last 7 d of the 19-d experimental period. The individual feed intake characteristics consisting of latency time (interval between weaning and first feed intake), initial feed intake (intake during the first 24 h following the first feed intake), the number of total visits per day, and the number of visits in which feed was consumed, together with the time and the feed intake per visit, were determined for all piglets. Performance traits and fecal consistency were determined per pen for d 0 to 5, d 5 to 12, and d 12 to 19, as well as for the total period (d 0 to 19). The initiation of feed intake was not affected by the addition of high intensity sweeteners to the diet. From 12 d postweaning, dietary sweeteners caused the piglets to focus more on feed intake and less on exploratory behavior, as shown by the increased percentage of visits with feed intake in pigs fed the Sucram 3D diet compared with those fed the control diet (P = 0.002). The overall daily feed intake increased with time but was not affected by the addition of sweeteners. Nevertheless, dietary sweeteners prevented the depression of feed intake on d 8 and 10 postweaning (d 8, P = 0.013; d 10, P = 0.014), which seemed to coincide with an improved fecal consistency score (d 5 to 12, P = 0.11; d 12 to 19, P < 0.001). However, the changes in feed intake characteristics and fecal consistency only resulted in numerical effects on postweaning pig performance (ADFI, P = 0.126; ADG, P = 0.140). The results of the present study indicate that weanling pigs need a certain period of time before clear effects of dietary sweeteners on individual feed intake characteristics and pig performance can be observed.     

酵母抽提物替代血浆蛋白粉对断奶仔猪生产性能的影响

试验旨在研究酵母抽提物部分或全部替代血浆蛋白粉对断奶仔猪生产性能的影响。试验共选160头体重([6.20±0.10)kg]和日龄([26±2)d]相近的PIC断奶仔猪,分为4个处理,每个处理5个重复,每个重复8头仔猪。对照组(处理1)饲喂基础日粮,处理2饲喂含4%血浆蛋白粉(SDPP)日粮,处理3饲喂含2%SDPP+2%酵母抽提物的日粮,处理4饲喂含4%酵母抽提物日粮。试验期为28 d,所有仔猪自由采食和饮水。结果表明,与对照组相比,饲喂含4%酵母抽提物日粮能促进仔猪生长,试验全期仔猪日增重提高15%(P<0.05),饲料增重比降低7%(P<0.05);与含4%或2%SDPP日粮组相比,饲喂含4%酵母抽提物日粮并没有显著影响仔猪平均日采食量和日增重,但饲料增重比在试验前3周和试验全期均得到显著改善(降低7%～10%,P<0.05)。因此,酵母抽提物能促进断奶仔猪生长,部分或全部替代SDPP不影响仔猪增重,且能改善饲料转化率。     

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.     

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.     

Effect of removal and remixing of lightweight pigs on performance to slaughter weights

Two experiments were conducted to determine the effect of lightweight pig removal and remixing on performance to slaughter. Experiment 1 was a growing-finishing trial utilizing a total of 900 pigs (26.2+/-0.1 kg initial weight) that were sorted and remixed at a mean replicate BW of 72 kg. Experiment 2 was a wean-to-finish trial (17 d mean wean age; 4.8 kg +/- 0.1 BW) utilizing 225 barrows with sorting and remixing occurring 3 wk after weaning. Treatments were 15 pigs/ pen from initial weight to slaughter (15S), 20 pigs/pen from initial weight to time of sort and remix and then reduced to 15 pigs/pen (20/15), and 15 pigs/pen from time of sort and remix to slaughter comprised of the five lightest pigs from each of three 20/15 pens per replicate (15M). Space allocation was 0.56 m2/pig from 26 to 70 kg and 0.74 m2/pig thereafter in Exp. 1. In Exp. 2, pen size was fixed at 2.44 x 4.27 m. In Exp. 1, there was no effect (P > 0.20) of treatment on performance prior to 70 kg. Least squares means for ADG from time of sort and remix to first pig removal from a pen for slaughter at 113 kg were 0.93, 0.87, and 0.91 kg/d for the 20/15, 15M, and 15S treatments, respectively (P < 0.05). When comparing the population represented by the 20/15 + 15M treatments vs the 15S population, there was no difference (P > 0.20) in ADG, ADFI, feed conversion, or carcass lean content. In Exp. 2, pigs in the 20/15 treatment grew slower (P < 0.05) than 15S pigs for the first 21 d (0.20 vs 0.22 kg/d, respectively) with a lower ADFI (P = 0.06) and no difference in feed conversion. When comparing the population represented by the 20/15 + 15M treatments vs the 15S population after sorting and remixing, there was no effect (P > 0.15) of experimental treatments on ADG, ADFI, feed conversion efficiency, carcass lean content, or daily lean gain. These results suggest that removal of lightweight pigs and remixing of the removed pigs into pens of similar-weight pigs is ineffective in improving the overall performance of a population of pigs during the postweaning period.     

Effects of dietary humic substances on pig growth performance, carcass characteristics, and ammonia emission

Five experiments were conducted to test the effects of various dietary humic substances (HS; HS1, 2, 3, and 4, each with different fulvic and humic acid contents) on pig growth, carcass characteristics, and ammonia emission from manure. In Exp. 1, 120 pigs were allotted to 3 dietary treatments without HS (control) or with HS1 at 0.5 and 1.0% (8 pens/treatment and 5 pigs/pen) and fed diets, based on a 5-phase feeding program, from weaning (d 21.3 +/- 0.3 of age) to 60 kg of BW. In Exp. 2 and 3, 384 pigs (192 for each experiment) were allotted to 3 dietary treatments without HS, with HS1, or with HS2 (0.5%) for Exp. 2 and without HS, or with HS3 or HS4 (0.5%) for Exp. 3 (8 pens/treatment and 8 pigs/pen in each experiment). Pigs were fed diets, based on a 6-phase feeding program, from weaning (25.4 +/-0.2 and 23.6 +/-0.3 d of age for Exp. 2 and 3, respectively) to 110 kg of BW. In Exp. 4, 96 pigs were weaned at 22.1 +/-0.2 d of age and allotted to 2 treatments without or with HS1 at 0.5% (6 pens/treatment and 8 pigs/pen), and in Exp. 5 96 pigs were weaned at 20.9 +/-0.3 d of age and allotted to 3 treatments without HS, or with HS3 or HS4 (0.5%; 4 pens/treatment and 8 pigs/pen). Pigs were fed the diets for at least 2 wk before they were moved to an environmental chamber to measure aerial ammonia and hydrogen sulfide for 48 h at 5-min intervals. In Exp. 1, pigs fed diets with HS1 at 0.5% had greater (P < 0.05) ADG during phase 3 and greater (P < 0.05) G:F during phases 3 and 5 than control pigs. In Exp. 2, pigs fed diets with HS1 or HS2 at 0.5% had greater (P < 0.05) ADG and G:F than control pigs during the entire feeding period, whereas in Exp. 3 HS3 or HS4 did not improve pig growth performance. Ammonia emission from manure was reduced by 18 or 16% when pigs were fed diets with HS1 (P = 0.067) or HS4 (P = 0.054), respectively. The results of this study indicate that the effects of dietary HS are variable but may improve growth performance of pigs and reduce ammonia emission from manure. Further research is needed to clarify these effects and the mechanisms by which HS may cause them.     

Improvement of growth performance and sanitary status of weaned piglets fed a bovine colostrum-supplemented diet

The present study investigated the effect of 3 different durations of feeding a diet supplemented with defatted bovine colostrum (Col) on growth performance and sanitary status of the weaned piglet. At 28 d of age, piglets were weaned and fed 1 of the 2 following diets: a control (Ctrl) starter diet or a starter diet supplemented with Col. Two experiments were conducted. In Exp. 1, 310 piglets (12 pens consisting of 10 piglets/pen and 10 pens consisting of 19 piglets/pen) were allocated to 1 of the 2 dietary treatments for 12 d. In Exp. 2, 522 piglets (18 pens consisting of 10 piglets/pen and 18 pens consisting of 19 piglets/pen) were allocated to 1 of the following 3 dietary treatments: fed the Ctrl diet from d 1 to 12 (Ctrl), Col diet from d 1 to 4 and then the Ctrl diet up to d 12 (Col-4d), or the Col diet from d 1 to 6 and then the Ctrl diet up to d 12 (Col-6d). For both experiments, a commercial second-phase diet was fed to piglets from d 12 to 46. Feed intake, growth performance, and cleanliness of floor and hindquarters of animals were investigated during the first 7 wk postweaning. In Exp. 1, from d 0 to 12, ADFI, ADG, and G:F were 16 (P = 0.004), 23 (P < 0.001), and 5% (P = 0.069) greater, respectively, in Col piglets compared with Ctrl piglets. Thereafter, ADFI and ADG were 7 (P < 0.001) and 9% (P < 0.001) greater, respectively, in Col piglets than Ctrl piglets (d 12 to 46). On d 12 after weaning, piglets fed the Col diet had more normal feces (+13%) and less soft or liquid feces (-9 and -4%, respectively) than piglets fed the Ctrl diet (P = 0.06). Compared with Ctrl piglets, feeding the Col diet led to more days with normal feces for the floor cleanliness (+22%; P < 0.001) from d 7 to 11. In Exp. 2, compared with Ctrl piglets, ADFI, ADG, and G:F were 8, 23, and 13% greater (P < 0.05) in Col-6d piglets from d 0 to 9, whereas values for Col-4d piglets were intermediate and did not differ from the values of the other dietary treatments. On d 9 after weaning, piglets fed the Col-4d or the Col-6d diet had more normal feces (+6 and +4%, respectively) and less liquid feces (-4 and -3%, respectively) than piglets fed the Ctrl diet (P = 0.08). No long lasting effects were observed thereafter. In conclusion, there was a reduction of weaning-induced growth check and diarrheal episodes in weaned piglets fed the Col diet. The beneficial effects of the bovine colostrum were observed beyond the period of treatment when the supplementation covered the first 6 d postweaning, which corresponded to the acute phase of postweaning digestive disturbances.     

Effects of feeder-trough space and variation in body weight within a pen of pigs on performance in a wean-to-finish production system

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.     

Nutritional evaluation of egg byproducts in diets for early-weaned pigs

A total of 272 Cotswold pigs (17 +/- 1 d) were utilized in three experiments to evaluate the nutritive value of spray-dried egg proteins for early-weaned pigs. In all experiments, pigs were stratified by sex and initial BW and then assigned randomly to experimental diets. In Exp. 1, four corn-soybean meal-based diets containing 7% of either spray-dried porcine plasma (SDPP), spray-dried technical albumen (SDTA), SDTA stored at 70 degrees C for 3 d (SDTA-ht), or spray-dried whole egg (SDWE) were assigned to five pens each with four pigs for a 3-wk study period. Average daily gain, ADFI, and gain:feed ratio (G:F) were determined. At the end of wk 3, five pigs per treatment were killed to determine ileal AA and energy digestibilities, as well as Enterobacteriaceae counts. Compared with the SDPP diet, ADG and G:F were lower (P < 0.05) for SDTA-, SDTA-ht- and SDWE-containing diets. Apparent ileal digestibilities of cystine, histidine, isoleucine, methionine, and threonine in the SDPP diet were lower (P < 0.05) than in diets containing spray-dried egg products. Ileal digestible energy content did not differ (P > 0.05) in all diets (3.1 to 3.2 Mcal/kg). Enterobacteriaceae counts were lower in the SDTA-ht diet than in either the SDTA or SDWE diets (P < 0.05). In Exp. 2, the effect of substituting SDPP with varying levels of SDTA was investigated. Diets were randomly assigned to five pens (except for the 100% SDTA diet, which had four pens), each with four pigs. Average daily gain, ADFI, and G:F decreased linearly as the level of SDTA was increased in the diet (P < 0.05). Replacing SDPP with SDTA at 25 or 50% had no effect on pig performance (P > 0.10). In Exp. 3, phase I diets containing 0, 25, or 50% SDTA in place of SDPP (7% of the diet) were each assigned at random to eight pens each with four pigs for a 14-d period, after which all pigs were switched to a common phase II diet lacking both SDPP and SDTA for another 14 d. Average daily feed intake and ADG did not differ among all diets in phase I and II and overall (d 0 to 28). Pigs fed the diet containing 50% SDTA in phase I had lower (P < 0.05) G:F than those fed the SDPP diet. The results indicate that technical albumen can replace 25 to 50% of SDPP in early-weaned pig diets without compromising performance, and further suggest that heat-treated SDTA may affect intestinal microbial population in pigs.     

Effect of chito-oligosaccharide on growth performance, intestinal barrier function, intestinal morphology and cecal microflora in weaned pigs

A total of 180 weanling pigs (21 ± 3 d of age; 5.98 ± 0.04 kg) were used to investigate the effect of chito-oligosaccharide (COS) on growth performance, intestinal barrier function, intestinal morphology, and cecal microflora. Based on initial BW, gender and litter, the pigs were given 5 treatments during a 14-d feeding experiment, including a basal diet (control), 3 diets with COS supplementation (200, 400, or 600 mg/kg), and a diet with colistin sulfate (CSE) supplementation (20 mg/kg). Six randomly selected pigs from each treatment were used to collect serum, duodenal, jejunal, ileal, and cecal samples on d 7 and 14 postweaning. From d 1 to 7 postweaning, pigs fed COS or CSE had greater ADG and ADFI compared with the control pigs. From d 1 to 14, diets with either 400 or 600 mg/kg COS, or 20 mg/kg CSE increased (P < 0.05) ADG and G:F compared with the control diet. No significant differences were observed in ADG, ADFI, and G:F between the pigs fed COS and CSE. Pigs fed either 400 or 600 mg/kg COS, or 20 mg/kg CSE had less (P < 0.05) diamine oxidase (DAO) in the serum, but greater concentration of (P < 0.05) DAO in jejunal mucosa, than the control pigs on d 7 postweaning. Treatments did not affect villous height and crypt depth of the duodenum, jejunum, or ileum. Pigs fed COS at 400 mg/kg had greater (P < 0.05) concentration of Bifidobacteria and Lactobacilli in the cecum than pigs fed the control diet and CSE diet on d 7 postweaning. Supplementation of COS or CSE decreased (P < 0.05) the population of cecal Staphylococcus aureus compared with the control diet on d 7 postweaning. The number of cecal Bifidobacteria in pigs fed 600 mg/kg COS was greater (P < 0.05) than that of pigs fed the control diet or CSE diet on d 14 postweaning. No significant differences were observed in Escherichia coli counts in the cecum among treatments. The present results indicate that dietary supplementation of COS at 400 or 600 mg/kg promotes growth performance and improves gut barrier function, increases the population of Bifidobacteria and Lactobacilli, and decreases S. aureus in the cecum of weanling pigs.     

Response of early-weaned pigs to spray-dried porcine or animal plasma-based diets supplemented with egg-yolk antibodies against enterotoxigenic Escherichia colil

Two experiments involving 168 10-d-old weaned pigs were conducted to compare growth-promoting properties of dietary spray-dried animal plasma (SDAP), spray-dried porcine plasma (SDPP), and chicken egg-yolk antibodies (EYA) or egg-yolk powder (EYP, contains no specific antibodies) from d 0 to 14 postweaning. In Exp. 1, 96 pigs (3.2 +/- 0.2 kg BW) were used to test the hypothesis that the superior performance of piglets fed SDPP-based diets was partly due to the presence of specific antibodies against enterotoxigenic Escherichia coli (ETEC), which could be replaced with EYA. Four experimental diets in a completely randomized design and arranged in a 2 x 2 factorial (SDPP without or with autoclaving [AuSDPP] and without [EYP] or with supplementation of EYA) were used. Autoclaving SDPP at 121degrees C for 15 min completely destroyed anti-K88/F18 antibodies. Overall feed intake and gain:feed ratio were similar (P > 0.05) among treatments and averaged 122.7 g/d and 0.688, respectively. However, pigs fed AuSDPP+EYP diets had poorer (P < 0.001) ADG compared with those fed SDPP+EYP or SDPP+EYA from 0 to 14 d. Scours were four times higher (P < 0.05) for treatment AuSDPP+EYP compared with all other treatments. Plasma urea nitrogen concentration was higher (P < 0.05) in AuSDPP+EYP- and AuSDPP+EYA-fed pigs. Also twice the number of piglets fed AuSDPP+EYP appeared unhealthy compared with piglets on treatment AuSDPP+EYA. In Exp. 2, 72 10-d-old weaned pigs (3.5 kg BW) were used to compare the effect of EYA supplementation and oral challenge of ETEC strain F18 on performance and visceral organ weights. The experimental diets consisted of SDAP+EYP, SDAP+EYA, SDPP+EYP, and SDPP+EYA. From d 0 to 7, and the entire experimental period, dietary treatment did not influence (P > 0.05) growth rate and feed consumption. Plasma urea N concentration was higher (P < 0.05) in piglets fed the SDAP+EYP diet before and after the oral challenge. Gain:feed ratio, organ weights, villi heights, and crypt depths were not affected (P > 0.05) by dietary treatments. The results indicate that SDPP contains specific anti-ETEC antibodies, which is one of the factors responsible for its superior growth-enhancing effects. Spray-dried animal plasma, SDPP and EYA have similar growth promoting effect in early-weaned pigs.     

Use of pet food-grade poultry by-product meal as an alternate protein source in weanling pig diets

Three experiments were conducted to evaluate pet food-grade poultry by-product meal (PBM) as a replacement protein source for fish meal (FM), blood meal (BM), and spray-dried plasma protein (SDPP) in weanling pig diets. In the first study, 200 crossbred pigs (initial BW = 6.5 kg) were weaned (21 d) and randomly allotted to one of four dietary treatments, which included a control and three test diets where PBM was substituted for FM, blood products, or both. Experimental diets were fed during Phase I (d 0 to 5 postweaning) and Phase II (d 5 to 19), and a common Phase III diet was fed from d 19 to 26. Overall (d 0 to 26), there was no difference in performance of pigs fed PBM in place of the other ingredients. However, during Phase I, BW (P < 0.05), ADG (P < 0.02), and intake (P < 0.001) in pigs fed diets containing SDPP were greater than those fed diets with PBM. In Exp. 2, the performance of pigs (n = 100, initial BW = 6.5 kg) fed diets containing 20% PBM (as-fed basis, replacing SDPP, BM, FM, and a portion of the soybean meal) in all phases of the nursery diet was compared with a group fed conventional diets without PBM. There were no differences in overall performance (d 0 to 26); however, ADG (P < 0.10) and feed intake were higher (P < 0.01) for pigs fed the conventional diet than for pigs fed the 20% PBM diet during Phase I (d 0 to 5). Experiment 3 was a slope-ratio assay to determine the ability of PBM to replace SDPP. A total of 320 pigs (initial BW = 7.32 kg) was weaned (21 d) and allotted to five treatment groups in three trials in a blocked design with product (SDPP or PBM) as the first factor, and lysine level (1.08, 1.28, 1.49%; as-fed basis) as the second factor. Growth rate increased with increasing lysine (P < 0.05), regardless of the source. These results indicate that PBM can be used in nursery diets in place of blood meal and fish meal without affecting performance. Furthermore, although feeding PBM in Phase I diets was not equivalent to SDPP during the first week, there was no overall difference in performance at the end of the nursery phase.     

Effects of beta-glucan extracted from Saccharomyces cerevisiae on growth performance, and immunological and somatotropic responses of pigs challenged with Escherichia coli lipopolysaccharide

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.     

Copper proteinate in weanling pig diets for enhancing growth performance and reducing fecal copper excretion compared with copper sulfate

Two 28-d experiments were conducted to evaluate the efficacy of low dietary concentrations of Cu as Cu-proteinate compared with 250 ppm Cu as CuSO4 with growth performance, plasma Cu concentrations, and Cu balance of weanling swine as the criteria. In the production study (Exp. 1), 240 crossbred pigs that averaged 19.8 d of age and 6.31 kg BW initially were group-fed (two or three pigs per pen) the basal diets (Phase 1: d 0 to 14 and Phase 2: d 14 to 28) supplemented with 0 (control), 25, 50, 100, or 200 ppm Cu as Cu-proteinate, or 250 ppm Cu as CuSO4 (as-fed basis). The basal diets contained 16.5 ppm Cu supplied as CuSO4 before supplementation with Cu-proteinate or 250 ppm Cu as CuSO4. There were quadratic responses (P < or = 0.05) in ADFI and ADG for wk 1, Phases 1 and 2, and overall because ADFI was higher for pigs fed 25 or 50 ppm Cu as Cu-proteinate, and ADG increased with increasing Cu-proteinate up to 50 ppm Cu. The Cu-proteinate treatment groups combined had a higher (P < or = 0.05) Phase 2 and overall ADFI and ADG than the CuSO4 group. In the mineral balance study (Exp. 2), 20 crossbred barrows that averaged 35 d of age and 11.2 kg/BW initially were placed in individual metabolism pens with total urine and fecal grab sample collections on d 22 to 26. Treatments were the basal Phase 2 diet supplemented with 0, 50, or 100 ppm Cu as Cu-proteinate, or 250 ppm Cu as CuSO4 (as-fed basis). Treatments did not differ in growth performance criteria. There were linear increases (P < 0.001) in Cu absorption, retention, and excretion (milligrams per day) with increasing Cu-proteinate. Pigs fed 100 ppm Cu as Cu-proteinate absorbed and retained more Cu and excreted less Cu (mg/d, P < or = 0.003) than pigs fed 250 ppm Cu as CuSO4. Plasma Cu concentrations increased linearly (P = 0.06) with increasing Cu-proteinate. In conclusion, weanling pig growth performance was increased by 50 or 100 ppm Cu as Cu-proteinate in our production Exp. 1, but not in our balance Exp. 2, compared with 250 ppm Cu as CuSO4. However, 50 or 100 ppm Cu as Cu-proteinate increased Cu absorption and retention, and decreased Cu excretion 77 and 61%, respectively, compared with 250 ppm Cu as CuSO4.     

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

Four experiments were conducted to determine the interactive effects of pharmacological amounts of Zn from ZnO and Cu from organic (Cu-AA complex; Cu-AA) or inorganic (CuSO(4)) sources on growth performance of weanling pigs. The Cu was fed for 4 (Exp. 1) or 6 (Exp. 2, 3, and 4) wk after weaning, and Zn was fed for 4 (Exp. 1) or 2 (Exp. 2, 3, and 4) wk after weaning. Treatments were replicated with 7 pens of 5 or 6 pigs per pen (19.0 ± 1.4 d of age and 5.8 ± 0.4 kg of BW, Exp. 1), 12 pens of 21 pigs per pen (about 21 d of age and 5.3 kg of BW, Exp. 2), 5 pens of 4 pigs per pen (20.3 ± 0.5 d of age and 7.0 ± 0.5 kg of BW, Exp. 3), and 16 pens of 21 pigs per pen (about 21 d of age and 5.7 kg of BW, Exp. 4). In Exp. 1 and 2, Cu-AA (0 vs. 100 mg/kg of Cu) and ZnO (0 vs. 3,000 mg/kg of Zn) were used in a 2 × 2 factorial arrangement. Only Exp. 1 used in-feed antibiotic (165 mg of oxytetracycline and 116 mg of neomycin per kilogram feed), and Exp. 2 was conducted at a commercial farm. In Exp. 3, sources of Cu (none; CuSO(4) at 250 mg/kg of Cu; and Cu-AA at 100 mg/kg of Cu) and ZnO (0 vs. 3,000 mg/kg of Zn) were used in a 3 × 2 factorial arrangement. In Exp. 4, treatments were no additional Cu, CuSO(4) at 315 mg/kg of Cu, or Cu-AA at 100 mg/kg of Cu to a diet supplemented with 3,000 mg/kg of Zn from ZnO and in-feed antibiotic (55 mg of carbadox per kilogram of feed). In Exp. 1 and 2, both Zn and Cu-AA improved (P < 0.001 to P = 0.03) ADG and ADFI. No interactions were observed, except in wk 1 of Exp. 2, where Zn increased the G:F only in the absence of Cu-AA (Cu-AA × Zn, P = 0.04). A naturally occurring colibacillosis diarrhea outbreak occurred during this experiment. The ZnO addition reduced (P < 0.001) the number of pigs removed and pig-days on antibiotic therapy. In Exp 3, ADFI in wk 2 was improved by Zn and Cu (P < 0.001 and P = 0.09, respectively) with no interactions. In wk 1, G:F was reduced by ZnO only in the absence of Cu (Cu × Zn, P = 0.03). Feeding Zn decreased fecal microbiota diversity in the presence of CuSO(4) but increased it in the presence of Cu-AA (Cu source × Zn, P = 0.06). In Exp. 4, Cu supplementation improved the overall ADG (P = 0.002) and G:F (P < 0.001). The CuSO(4) effect on G:F was greater (P < 0.001) than the Cu-AA effect. Our results indicate that pharmacological amounts of ZnO and Cu (Cu-AA or CuSO(4)) are additive in promoting growth of pigs after weaning.     

Effect of dietary copper source (cupric citrate and cupric sulfate) and concentration on growth performance and fecal copper excretion in weanling pigs

In each of two experiments, 924 pigs (4.99 kg BW; 16 to 18 d of age) were assigned to 1 of 42 pens based on BW and gender. Pens were allotted randomly to dietary copper (Cu) treatments that consisted of control (10 ppm Cu as cupric sulfate, CuSO4 x 5H2O) and supplemental dietary Cu concentrations of 15, 31, 62, or 125 ppm as cupric citrate (CuCit), or 62 (Exp. 2 only), 125 (Exp. 1 only), or 250 ppm as CuSO4. Live animal performance was determined at the end of the 45-d nursery phase in each experiment. On d 40 of Exp. 2, blood and fecal samples were collected from two randomly selected pigs per pen for evaluation of plasma and fecal Cu concentrations and fecal odor characteristics. In Exp. 1, ADG, ADFI, and G:F were increased (P < 0.05), relative to controls, when pigs were fed diets containing 250 ppm Cu as CuSO4. Pigs fed diets containing 125 ppm Cu as CuCit had increased (P < 0.05) ADG compared with pigs fed diets supplemented with 15 or 62 ppm Cu as CuCit. The ADG, ADFI, and G:F did not differ among pigs fed diets containing 125 and 250 ppm Cu as CuSO4 or 125 ppm Cu as CuCit. In Exp. 2, pigs fed diets containing 250 ppm Cu as CuSO4 had improved (P < 0.05) ADG, ADFI, and G:F compared with controls. In addition, ADG, ADFI, and G:F were similar when pigs were fed diets containing either 250 ppm Cu as CuSO4 or 125 ppm Cu as CuCit. Pigs fed diets containing 62 ppm Cu as CuSO4 or CuCit had similar ADG, ADFI, and G:F. Plasma Cu concentrations were not affected by dietary Cu source or concentration, but fecal Cu concentrations were increased (P < 0.05) as the dietary concentration of Cu increased. Pigs consuming diets supplemented with 125 ppm Cu as CuCit had fecal Cu concentrations that were lower (P < 0.05) than pigs consuming diets supplemented with 250 ppm Cu as CuSO4. Fecal Cu did not differ in pigs receiving diets supplemented with 62 ppm Cu as CuSO4 or CuCit. Odor characteristics of feces were not affected by Cu supplementation or source. These data indicate that 125 and 250 ppm Cu gave similar responses in growth, and that CuCit and CuSO4 were equally effective at stimulating growth and improving G:F in weanling pigs. Fecal Cu excretion was decreased when 125 ppm Cu as CuCit was fed compared with 250 ppm Cu as CuSO4. Therefore, 125 ppm of dietary Cu, regardless of source, may provide an effective environmental alternative to 250 ppm Cu as CuSO4 in weanling pigs.     

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.     

Effects of spray-dried porcine plasma and plant extracts on intestinal morphology and on leukocyte cell subsets of weaned pigs

We evaluated the effects of a 6% spray-dried porcine plasma (SDPP) and a plant extracts mixture (XT; 5% carvacrol, 3% cinnamaldehyde, and 2% capsicum oleoresin) on the productive performance, intestinal morphology, and leukocyte cell subsets of early-weaned pigs compared with a control group. Morphometry of the jejunum, ileum, and colon, and immune cell analysis of blood, ileocolic lymph node (LN), and ileal Peyer's patches were done in 24 weaned pigs (20 +/- 2 d) at 19 or 21 d postweaning. Although SDPP and XT treatments did not increase ADG or ADFI, SDPP improved the G:F ratio (P = 0.024) compared with the control group. Dietary SDPP reduced the percentages of blood monocytes (P = 0.006) and macrophages in ileal Peyer's patches and LN (P = 0.04), of B lymphocytes (P = 0.04) and gammadelta+ T cells in LN (P = 0.009), and of intraepithelial lymphocytes (P = 0.026) as well as the density of lamina propria cells in the colon (P < 0.01). Dietary XT reduced intraepithelial lymphocyte numbers in jejunum (P = 0.034) and the percentages of blood cytotoxic cells (P = 0.07) and B lymphocytes in LN (P = 0.03); however, XT increased blood monocytes (P = 0.038) and the density of lamina propria lymphocytes in the colon (P = 0.003). These results indicate that dietary SDPP and plant extracts can affect intestinal morphology and immune cell subsets of gut tissues and blood in weaned pigs. Furthermore, the effects of SDPP suggest lower activation of the immune system of the piglets.     

Response of early-weaned pigs to an enterotoxigenic Escherichia coli (K88) challenge when fed diets containing spray-dried porcine plasma or pea protein isolate plus egg yolk antibody,zinc oxide,fumaric acid,or antibiotic

The effect of feeding diets containing either spray-dried porcine plasma (SDPP) or pea protein-isolate (PPI) supplemented with either egg yolk antibodies (EYA) from hens immunized with enterotoxigenic Escherichia coli (ETEC) (K88 and F18) antigens, ZnO, fumaric acid (FA), or carbadox (AB) on pig performance, incidence of scours, and gut morphology was studied in a 14-d experiment. Ninety 10-d-old weaned pigs were assigned to six dietary treatments in a completely randomized design to give five pens per treatment with three pigs per pen. The diets were SDPP without EYA (SDPP - EYA), PPI without EYA (PPI - EYA), PPI with EYA (PPI + EYA), PPI with ZnO (PPI + ZnO), PPI with FA (PPI + FA), or PPI with AB (PPI + AB). Diets were formulated to similar nutrient levels, with AB, EYA, FA, and ZnO at 0.25, 0.5, 2.0, and 0.4% of the diet, respectively. Pigs were weighed and bled on d 0, 7, and 14 to determine plasma urea N (PUN). Pigs were orally challenged with a 6-mL dose of 10(10) cfu/mL ETEC (K88) on d 7. On d 14, three pigs per treatment were killed to obtain sections of the small intestine for histological measurements. Weekly feed intake, BW changes, and gain:feed were determined. Incidence of scours and scour scores were monitored and fecal swabs were taken before and after ETEC challenge for PCR test to detect ETEC (K88). Feeding SDPP or supplementing PPI-based diets with EYA, ZnO, FA, or AB did not affect (P > 0.05) ADG, ADFI (as-fed basis), or gain:feed throughout the study. However, pigs fed PPI - EYA tended to have lower (P = 0.08) ADFI during wk 2 (137.9 g/d) and lower (P < 0.10) ADG from d 0 to 14 (100.1 g/d) than those fed the SDPP - EYA (156.6 g/d), PPI + EYA (151.2 g/d), PPI + ZnO (158.9 g/ d), PPI + FA (155.4 g/d), and PPI + AB (152.6 g/d) diets. Although scours was evident in all pigs 8 h after the ETEC challenge, it lasted only 3 to 5 d in pigs fed SDPP or PPI supplemented with EYA, ZnO, FA, or AB. Pigs fed PPI - EYA continued to have severe diarrhea, resulting in 40% mortality vs. 13% or less in the other groups. The PCR results showed that 81% of PPI-fed pigs continued to shed ETEC K88 7 d after ETEC challenge. Pigs fed PPI-EYA had shorter villi (P < 0.05), reduced villi:crypt ratio (P < 0.003), and higher intestinal pH (P < 0.001) and PUN (P < 0.001) than those fed SDPP or PPI supplemented with EYA, ZnO, FA, and AB. In conclusion, SDPP, EYA, ZnO, FA, and AB may have provided passive control to ETEC (K88) infection and potentially enabled young pigs to efficiently utilize a PPI-based diet.     

Effect of wean-to-finish management on pig performance

In each of three trials, 240 crossbred barrows weaned at 17 d of age (5.1 kg BW) were assigned to one of three experimental treatments based on light and heavy weight outcome groups. Experimental treatments were 1) wean-to-finish at 0.69 m2/pig and 15 pigs/pen; 2) wean-to-finish double-stocked at 0.35 m2/pig, 30 pigs per pen for 8 wk and then randomly split into two pens (either stayed in same pen or moved to new pen) for growth to slaughter at 0.69 m2/pig; and 3) nursery facility for 8 wk at 0.35 m2/pig and 15 pigs/pen followed by move to the same grow-finish facility housing wean-to-finish and double-stocked pigs and maintaining pen integrity. Beginning at 38 kg BW, diets were supplemented with either bacitracin methylenedisalicylate at 33 mg/kg to slaughter or tylosin at 44 mg/kg to 59 kg BW and 22 mg/kg thereafter. There were no trial x treatment interactions, even though there was considerable variation in health status among trials. At the end of the 56-d nursery period, wean-to-finish pigs weighed more than nursery (28.7 vs 27.7 kg; P = 0.071) and double-stocked pigs (28.7 vs 26.9 kg; P = 0.002), due to greater ADG (wean-to-finish vs nursery; P = 0.062; wean-to-finish vs double-stocked; P = 0.002) and greater ADFI (wean-to-finish vs nursery; P = 0.024; wean-to-finish vs double-stocked, P = 0.002). There was no effect of treatments (P > 0.1) on ADG, feed conversion, carcass lean percentage, or lean gain during the growing-finishing period. There was also no effect of treatment (P > 0.1) on ADG or ADFI from weaning to slaughter. There was no difference (P > 0.1) between bacitracin methylenedisalicylate and tylosin for ADG, feed conversion, carcass lean percentage, or daily lean gain. These data suggest that housing 5-kg weaned pigs in fully slatted growing-finishing facilities from weaning to slaughter was not detrimental to overall performance. In this experiment, dietary additions of bacitracin methylenedisalicylate or tylosin from 38 kg BW to slaughter weight resulted in similar growth performance.