Effect of diet particle size and feeding of H2-receptor antagonists on gastric ulcers in swine

Four experiments were conducted to evaluate the effect of diet and the administration of H2-antagonists in feed on gastric ulcer formation and performance of growing-finishing swine. Pigs receiving a finely ground diet (less than lmm) grew faster (.73 vs .68 kg/d, P less than .01) and had better feed utilization (3.47 vs 3.76, P less than .01) than pigs receiving a cracked corn-based diet. Incidence of ulcers in the esophageal region of the stomach of pigs fed the finely ground diet was greater (P less than .01) than in pigs fed cracked corn. The average daily gain of pigs receiving the finely ground diet was inversely related to ulcer incidence (r = .403, P less than .01, df = 59). The addition of 5, 10, 20 or 100 ppm of the H2-antagonist, metiamide, or 6, 18 or 54 ppm of SK&F 93479 to the finely ground diet did not improve pig performance or affect the incidence of gastric ulceration. The addition of 2, 6 and 18 ppm of SK&F 93479 to a corn-soy diet containing 4.5% alfalfa meal caused a reduction in gastric ulceration (P less than .05) and improved feed utilization by 3.2% (P less than .05). These data suggest that finely ground diets improve the performance of growing-finishing swine, but increase the incidence of ulcers in the esophageal region of the stomach. Severe gastric ulceration adversely affects swine performance. Feeding H2-antagonists does not reduce the ulcerogenic properties of finely ground diets, suggesting factors other than gastric acid secretion are involved in ulcerogenesis. The use of H2-antagonists in corn-soy diets improves feed utilization and reduces ulceration.     

Effects of dried whey and copper sulfate on the growth responses to organic acid in diets for weanling pigs

Five 21-d to 28-d experiments involving 484 pigs weaned at 28 +/- 2 d of age were conducted to evaluate the effects of addition of organic acid to a fortified, corn-soybean meal diet (CS) or to a similar diet containing 15% dried whey (CSW) on performance of pigs. The effects of an antibiotic-sulfonamide combination (110 mg chlortetracycline, 110 mg sulfamethazine, 55 mg penicillin/kg) and the interactive effects of Cu sulfate (250 ppm Cu) and acid also were evaluated. The acid was a commercial product consisting of 96% organic acid (citric acid and Na citrate, 2:1). Treatments in Exp. 1 and 2 were factorial arrangements of the CS or CSW basal diets supplemented with 0 or 1% (Exp. 1) and 0, .5 or 1% (Exp. 2) of the acid product. Pigs fed diets containing whey consumed more feed (P less than .01) and gained weight faster (P less than .05), but they had feed/gain responses similar to those of pigs fed the CS diet. Addition of 1% acid improved (P less than .01) growth rate of pigs fed the CS diet but did not improve (P greater than .25) growth rate of pigs fed the CSW diet. Feed/gain was improved (P less than .01) by acid addition to both the CS and the CSW diets. Improvements in gain and feed/gain were similar for the two levels of acid. In Exp. 3 and 4, factorial combinations of 0 and 1% acid and 0 and 250 ppm Cu were evaluated in diets containing an antibiotic-sulfonamide combination. In addition, a negative control diet (no antibiotics, acid or Cu) was included. Pigs fed diets containing antibiotics gained faster and more efficiently (P less than .01) than those fed the control diet.(ABSTRACT TRUNCATED AT 250 WORDS)     

Impact of betaine on pig finishing performance and carcass composition

Two experiments were conducted to evaluate the effect of betaine supplementation of finishing diets on growth performance and carcass characteristics of swine. Experiment 1 included 288 pigs in a 2 x 2 x 3 factorial arrangement of treatments consisting of barrows and gilts of two genetic populations fed diets with 1.25 g/kg supplemental betaine from either 83 or 104 kg to 116 kg and control pigs fed betaine-devoid diets. Pigs were housed three pigs per pen with eight replicate pens per treatment. Diets were corn-soybean meal-based with 300 ppm added choline. Genetic populations differed (P < 0.05) in fat depth (2.24 vs 2.93 cm) and longissimus muscle depth (53.8 vs 49.1 mm) at 116 kg. Betaine reduced feed intake (P < 0.05); however, real-time ultrasound measurements were not affected. In Exp. 2, 400 pigs were used in a 2 x 2 x 2 factorial arrangement of treatments to evaluate the effect of sex (barrow or gilts), betaine (0 or 1 g/kg of diet), and crude protein (CP) (0.70% lysine = 12.7% CP or 0.85% lysine = 15.0% CP) when fed from 60 to 110 kg live weight. Pigs had been assigned to either a high- or low-protein feeding regimen at an average initial weight of 11.3 kg and were maintained on their respective protein levels throughout the experiment. For a 56-d period from 61.7 kg to 113.6 kg, pigs were fed diets with 300 ppm added choline. Within each protein level, pigs were randomly assigned to diets containing 0 or 1 g/kg betaine. Pigs were group-housed (four to five pigs per pen). Pig weight and feed intake were recorded every 28 d. Real-time ultrasound measurements were recorded initially and at d 28 on 64 pigs, and on all pigs prior to slaughter. Growth rate was fastest and feed intake greatest for barrows (P < 0.05) and for pigs receiving 12.7% crude protein. A crude protein x betaine interaction (P < 0.05) was observed from d 28 to 56 with pigs fed the 15% CP diet growing fastest when supplemented with 1 g/kg betaine, and pigs receiving the 12.7% CP diet growing fastest when the diets contained 0 g/kg betaine. Gilts more efficiently (P < 0.05) converted feed into body weight gain, as did pigs receiving the 12.7% CP diet (P < 0.05). Longissimus muscle area and fat measurements were unaffected by betaine or dietary protein on d 28. However, by d 56 betaine reduced average fat depth in barrows (P < 0.05; 3.21 vs 3.40 cm), but not in gilts. Betaine may be more effective at altering body composition in barrows than in gilts.     

Effect of neomycin, carbadox and length of adaptation to calorimeter on performance, fasting metabolism and gastrointestinal tract of young pigs

Five sets of littermate gilts (8.2 +/- .19 kg average initial weight) were randomly assigned within litter to a 16% protein corn-soybean meal basal diet (B), B + .308% neomycin, or B + 55 ppm carbadox. Each set was equally-fed individually once daily for 16 d in metabolism cages and 5 d in calorimeters. The average daily feed intake for 21 d was 276 g. Oxygen consumption and CO2 production were measured during an 8- to 24-h postprandial period on d 16, 19, 20 and 21, and during a 32- to 48-h postprandial period after the d 21 feeding. Pigs were killed 50 h postprandially for gastrointestinal tract measurements. Dietary supplementation of antimicrobial agents (neomycin and carbadox) resulted in improvements (P less than .01) in daily gain and efficiency of feed utilization and lower (P less than .05) small intestinal mass in pigs. There was no difference (P greater than .05) in daily gain, feed efficiency or small intestinal mass between pigs fed neomycin- or carbadox-supplemented diets. Whole-animal fasting O2 consumption and CO2 production measured during the 8- to 24-h or 32- to 48-h postprandial period were not affected (P greater than .05) by the supplementation or the source of dietary antimicrobial agents. There were no differences (P greater than .05) in 8- to 24-h fasting O2 and CO2 measurements determined on d 16, 19, 20 and 21, indicating that adaptation to calorimeters was not needed by the pigs.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of feed and water restriction and receiving diet crude protein on feeder pig performance

Two experiments were conducted to determine the effects of feed and water restriction and receiving diet crude protein level on feeder pig performance. In Exp. 1, a total of 239 commingled feeder pigs transported over 1,000 km were used in two trials. Pigs given access to feed and water (FW) at the market weighed more (P less than .0001) following marketing and transport than pigs given no feed and water (N) for the comparable 25-h market period (20.7 vs 19.6 kg). While FW pigs weighed less (P less than .02) than N pigs at the conclusion of the trials (93.9 vs 96.6 kg), there was no effect (P greater than .1) on overall average daily gain (.32 vs .35). There were no effects of receiving diets containing 12, 16 or 20% crude protein on daily gain, daily feed intake or feed efficiency for the overall growing-finishing period. Scour scores on d 8, 9, 10, 11, 13 and 14 post-arrival increased (P less than .01) with increased levels of protein in the receiving diets. In Exp. 2, a total of 360 crossbred feeder pigs was mixed and moved from a nursery to grower-finisher facilities in three trials, given feed and water access immediately (FWG) or denied access for 44 h (NG). At the end of the 44-h period, FWG pigs were heavier than NG pigs (P less than .0001; 18.3 vs 16.7 kg). There was no treatment effect on overall pig weight, daily gain or feed efficiency.     

Effect of various levels of avilamycin on the performance of growing-finishing swine

A series of 12 trials involving 1,710 crossbred pigs was conducted at eight geographical locations in the United States to determine the effect of avilamycin on average daily gain (ADG), average daily feed (ADF) and feed-to-gain ratio (F/G) of growing-finishing swine. Eight of 12 trials evaluated avilamycin concentrations at 0, 5, 10, 20, 40 and 60 ppm, while an additional four trials evaluated avilamycin concentrations at 0, 10, 20 and 40 ppm in swine grower and finisher diets fed ad libitum. All trials were conducted using a randomized complete block design with data from the 12 trials pooled for statistical analysis. Pigs fed 5, 10, 20, 40 or 60 ppm avilamycin had increased (P less than .05) ADG over control pigs. No differences were detected for ADF between control and avilamycin-fed pigs. Pigs fed 10, 20, 40 or 60 ppm avilamycin had improved (P less than .05) F/G over control animals. Average daily gain, ADF and F/G for pigs fed 0, 5, 10, 20, 40 or 60 ppm avilamycin were: 749, 763, 767, 769, 771 and 771 g; 2.38, 2.40 2.39, 2.41, 2.38 and 2.38 kg; and 3.17, 3.15, 3.12, 3.13, 3.09 and 3.09, respectively. Linear plateau procedures showed that the effective dose range of avilamycin for the growing-finishing phase is 5 to 10 ppm for improving ADG and 10 to 60 ppm for improving F/G.     

The efficacy of salinomycin as a growth promotant for swine from 9 to 97 kg

Six trials involving 586 pigs initially averaging 9 kg were conducted at three locations (two trials/location) to evaluate the effects of the dietary addition of 0, 27.5, 55, 82.5 and 110 ppm of a monocarboxylic polyether antibiotic, salinomycin, on feed intake, growth rate and feed efficiency of swine fed corn-soybean meal-based diets. Over the total trial (9 to 97 kg), quadratic improvements in gain (P less than .01) and feed:gain (P less than .04) occurred with increasing level of salinomycin, but feed intake was not affected (P greater than .25). Mean improvements for all drug levels over control values for the total trial were 4.3% for daily gain (P less than .01) and 3.4% for feed:gain (P less than .01). For the total trial, rate and efficiency of gain were optimized in pigs fed the 82.5-ppm level of salinomycin with an improvement of 5.2% in daily gain and 4.8% in feed:gain over pigs fed the control diet. The absence of any significant trial X treatment interaction suggests that the nature of the response was not dependent on differences in environment, management or other factors that existed among trial locations.     

Influence of level of dietary protein or energy on effects of ractopamine in finishing swine.

The effect of ractopamine, a beta-adrenergic agonist, on growth, nutrient utilization, and carcass composition was studied in pigs fed either 18% CP, 12% CP, or 18% CP restricted (RES = 67% of ad libitum) diets. The 18 and 12% CP diets provided 3.52 and 3.68 Mcal of DE/kg, respectively. All pigs were fed a low-protein (12% CP) diet during pretreatment growth from 15 to 60 kg. Ractopamine at 20 or 30 ppm (30 ppm for RES pigs) in the diet was fed from 60 kg live BW until slaughter at 105 kg (9 pigs/treatment). No ractopamine treatment effect (P greater than .05) was observed for either daily gain or gain/feed, although gain/feed was improved by 8% in both of the ad libitum groups. Ractopamine treatment resulted (P less than .01) in an overall reduction of carcass lipid by 8%, an increase of carcass protein by 5%, and a 21% improvement in the efficiency of protein utilization; the greatest changes occurred in the pigs fed the 12% CP diet (-17%, +11%, and +32%, respectively). The ad libitum daily feed intake was 15% less for pigs fed the 12% CP diet than for those fed the 18% CP diet (P less than .01), and there was a 10% reduction in intake of both diets with the addition of ractopamine (P less than .05). Both carcass lipid and protein deposition seemed to be closely related to energy intake (P less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of ractopamine on genetically obese and lean pigs

Twenty-eight genetically obese and 24 lean barrows (65.0 and 68.7 kg average BW, respectively) were allotted within genotype to a 16% CP corn-soybean meal basal diet or this basal diet + 20 ppm ractopamine (a phenethanolamine beta-adrenergic agonist) and allowed ad libitum access to feed for 48 d. Compared to lean pigs, obese pigs had lower ADG, gain to feed ratio, longissimus muscle area, predicted amount of muscle, and weights of trimmed loin and ham, ham lean, heart, spleen, kidney and gastrointestinal tract (P less than .05). Obese pigs also had shorter carcass but higher dressing percentage, backfat thickness, fat depth, fat area, untrimmed loin weight and fasting plasma urea N concentration (P less than .05). Dietary supplementation with 20 ppm ractopamine reduced daily feed intake and improved gain to feed ratio in both lean and obese pigs (P less than .05). Pigs fed ractopamine had shorter carcasses, less fat depth and fat area, smaller weights of stomach and colon plus rectum, but higher dressing percentages, longissimus muscle areas, weights of trimmed Boston butts, picnics and loins, ham lean and predicted amounts of muscle than pigs not fed ractopamine (P less than .05). Supplemental ractopamine had no effect on fasting plasma concentrations of urea N, nonesterified fatty acids, triglyceride or glucose (P greater than .05). No genotype x ractopamine interactions for the criteria described above were detected (P greater than .05). These results suggest that ractopamine will improve the efficiency of feed utilization and carcass leanness in swine with different propensities for body fat deposition.     

Utilization by growing and finishing pigs of raw soybeans of low Kunitz trypsin inhibitor content

Three trials were conducted to compare acceptance and utilization by growing and finishing pigs of diets containing supplemental protein from either heated, solvent-extracted soybean meal (SBM), raw low-Kunitz trypsin inhibitor soybean (LT) or raw commercially grown Williams cultivar soybean with high Kunitz trypsin inhibitor content (HT). In Trial 1, 36 crossbred pigs, averaging 7 kg in weight, were fed 1) corn-SBM, 2)corn-LT or 3) corn-HT diets for 28 d. Diets were formulated to be isolysinic and to have similar calorie:lysine ratios. Average daily gain and gain/feed were higher (P less than .01) for pigs fed the corn-SBM diet than for pigs fed the corn-LT diet; average daily gain and gain/feed were higher (P less than .01) for the corn-LT diet than for the corn-HT. Average daily feed intake did not differ (P greater than .05) among diets. In Trial 2, 48 crossbred pigs averaging 67 kg were fed diets similar to those in Trial 1 but with lower lysine values. The daily gain (.95 kg) of pigs fed the corn-SBM diet was greater (P less than .05) than for pigs fed the corn-LT diet (.87 kg), which in turn was greater (P less than .05) than for the pigs fed the corn-HT diet (.83 kg). Daily feed intake (kg) and gain/feed were 3.27 and .291, 2.97 and .293, and 3.07 and .270, respectively, for pigs fed the corn-SBM, corn-LT and corn-HT diets. In Trial 3, 18 castrate male pigs averaging 12.4 kg were fed cornstarch-based diets with either SBM, LT or HT as the source of protein.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of chelated copper sources on performance of nursery and growing pigs

Four experiments were conducted to determine the effect of Cu source and level and an antimicrobial agent on performance of nursery (6 to 25 kg) and growing (20 to 65 kg) pigs. Copper was fed either as CuSO4.5H2O (CS), inorganic chelated Cu (ICC) or organic chelated Cu (OCC) to provide 31.25 to 250 ppm supplemental Cu. In Exp. 1, 224 pigs were used to study Cu source and level added to nursery diets. No difference (P less than .05) among treatments was observed during the nursery period. Treatments were continued the first 56 d of the growing-finishing period. Regardless of the Cu source, pigs receiving 125 ppm added Cu gained faster (P less than .05) than pigs in other treatments. In Exp. 2, 216 pigs were used to determine the optimum level of CS and ICC in nursery diets. Pigs were less efficient (P less than .01) when Cu was added at 62.5 and 125 ppm than at 250 ppm (1.69, 1.72 and 1.59, feed/gain respectively). In Exp. 3, no differences (P greater than .05) in performance between sources or among levels of Cu were found. In Exp. 4, 216 pigs were utilized to determine the combined effects of Cu source and an antimicrobial on performance. Pigs fed ICC were less efficient (P less than .01) than pigs fed either OCC or CS (1.99, 1.85 and 1.90, respectively). The inorganic and organic chelated Cu compounds used in these studies were not more efficacious than CS for nursery or growing pigs.     

The effect of various levels of ractopamine hydrochloride on the performance and carcass characteristics of finishing swine

Six trials involving 888 pigs (Study 1) and three trials involving 360 pigs (Study 2) were conducted at various geographical locations in the U.S. and Canada to evaluate the effect of ractopamine hydrochloride on the performance and carcass characteristics of finishing swine. All trials were conducted using a randomized complete block design. Trial data were pooled within study for statistical analysis. Pigs averaged approximately 64.5 kg (Study 1) and 65.9 kg (Study 2) initially and had ad libitum access to a 16% crude protein corn-soybean meal or barley-soybean meal diet. Ractopamine was included in the diet at 0, 2.5, 5, 10, 20 or 30 ppm (Study 1), or at 0, 5, 10, 15 or 20 ppm (Study 2); diets were fed for an average of 45 d (Study 1) and 50 d (Study 2) to a final weight of about 104.3 kg (Study 1) and 106.6 kg (Study 2). Carcass dissection data were collected in three of the six trials in Study 1 (0, 5 and 20 ppm ractopamine) and in all three trials in Study 2 (0, 5, 10, 15 and 20 ppm ractopamine). All ractopamine levels improved (P less than .05) ADG and feed: gain (Studies 1 and 2) above those of control pigs. Ractopamine levels of 10 to 30 ppm (Studies 1 and 2) improved (P less than .05) dressing percentage over controls. Pigs fed ractopamine at 5 and 20 ppm (Study 1) and 10, 15 and 20 ppm (Study 2) had increased (P less than .05) dissected leanness compared with controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of the beta-adrenergic agonist cimaterol (CL 263,780) on the growth and carcass characteristics of finishing swine

A randomized complete-block design was used to evaluate the effects of the beta-adrenergic agonist, cimaterol (CL 263,780), on growth rate, feed efficiency and carcass composition of finishing swine. The drug was fed at four levels (0, .25, .5 and 1.0 ppm) to a total of 240 pigs from 64.5 to 103.7 kg live weight. Growth rate and feed efficiency were measured during the 7-wk feeding trial. Feeding cimaterol depressed feed intake, improved feed efficiency and did not alter rate of gain. Carcass evaluation showed that pigs continuously fed cimaterol had 13.2, 9.3 and 9.2% less fat measured at the 10th rib, P2 and average backfat (BF) locations, respectively, compared with controls. Cimaterol-fed pigs had increased loin eye areas (10.9%), and increased semitendinosus (11.8%) and biceps femoris (8.9%) weights compared with controls. The semitendinosus muscles of the cimaterol-fed pigs had less fat and the femur bones were shorter and lighter weight than controls. There were no detected differences in structural soundness of the live pigs, but postmortem evaluation of the hooves indicated that pigs fed 1.0 ppm cimaterol had a higher incidence of hoof lesions. Pigs withdrawn from cimaterol for 7 d were comparable in performance and carcass characteristics with those continuously fed the drug except that carcass fat measurements had generally returned to control values. The data indicate that cimaterol improved the feed efficiency of finishing pigs and increased the lean:fat ratio of their carcasses. Withdrawal of cimaterol caused compensatory fat deposition.     

Evaluation of cimaterol for finishing swine including a drug withdrawal period

One hundred fifty crossbred pigs (55 kg) were allotted by weight, sex and litter to a randomized complete-block design with five dietary treatments, six blocks per treatment and five pigs per pen with sex equalized across treatments. Corn-soybean meal-based diets (.65% lysine) with 0, .25 and .5 mg/kg cimaterol were fed, on an ad libitum basis, to pigs slaughtered at an average pen weight of 104 kg/pig. Drug withdrawal prior to slaughter was 1, 3 and 5 d for pigs fed cimaterol at .25 mg/kg and 1 d for those fed cimaterol at .5 mg/kg of diet. Dietary cimaterol level influenced (quadratic, P less than .01) average daily gain during the first 42 d on test; however, daily feed intake and feed conversion ratio were not affected (P greater than .1). Pigs fed .25 mg/kg cimaterol with a 1-d drug withdrawal had 6.8, 7.7 and 13.5% less 10th rib fat depth and 11.1, 6.1 and 13.3% less P2 fat depth than those subjected to either a 3- or 5-d drug withdrawal or those fed the 0 mg/kg cimaterol diet (control), respectively. Overall, pigs fed cimaterol had 7.9% larger longissimus muscle area and 2.6% more kilograms of muscle than pigs fed the control diet. Cimaterol fed at .5 mg/kg resulted in higher (P less than .05) Warner-Bratzler shear force values and altered the proportion of saturation in some long-chain fatty acids, although the total saturated:unsaturated fat ratio was not affected. Pigs fed no cimaterol had less thaw loss (P less than .05) than did those fed other treatments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of selenium on performance, serum selenium concentration and glutathione peroxidase activity in pigs

Pigs from sows fed a diet deficient in Se and low in vitamin E were fed a Torula yeast diet supplemented with 100 IU dl-alpha-tocopheryl acetate/kg of diet. Dietary treatments were levels of supplemental Se of 0, .025, .050, .075 or .100 ppm. Some death loss occurred in pigs receiving no supplemental Se at approximately 5 wk of age. Autopsy revealed liver and heart lesions typical of vitamin E-Se deficiency. Selenium supplement had no significant effect on average daily gain, feed intake or gain to feed ratio for the 4-wk experiment. Selenium status of pigs was determined by serum Se concentration and serum glutathione peroxidase (GSH-Px) activity. Serum Se increased linearly (P less than .01) with increasing supplemental Se. Serum GSH-Px activity increased linearly (P less than .01) and quadratically (P less than .05) with increasing supplemental Se. With time, the level of serum Se and GSH-Px activity decreased in unsupplemental pigs, but increased in pigs fed diets supplemented with Se and resulted in significant interactions (P less than .01) between dietary Se level and time on experiment. The correlation between serum Se concentration and GSH-Px activity was .81 (P less than .01).     

Growth performance and carcass traits of pigs subjected to marginal dietary restrictions during the grower phase.

Sixty-four individually housed pigs were used to investigate the effect of amino acid content of finisher diets on growth performance of pigs subjected to marginal dietary amino acid restrictions (80% of the 1988 NRC lysine recommendation) during the grower phase. In each of the two trials, low- and high-amino-acid grower diets (.421 and .765 g lysine/MJ DE, respectively) and four finisher diets (.421, .516, .612, and .707 g lysine/MJ DE) were randomly assigned within sex to 16 gilts and 16 castrated males weighing 23.0 +/- 2.0 kg in a 2 x 4 factorial arrangement of treatments. The average weight of pigs after a completion of diet change was 50.4 +/- 2.1 kg. All pigs were slaughtered at an average weight of 105.2 +/- 4.1 kg. Ultrasound backfat thickness was measured at the time of diet change and before slaughter. Pigs were allowed ad libitum access to feed and water. During the grower phase, pigs fed the high-amino-acid diet grew faster (P < .001) and more efficiently (P < .001) and had less ultrasound backfat (P < .001) than those fed the low-amino-acid diet. The grower diet had no effect on weight gain during the finisher phase. Consequently, pigs fed the high-amino-acid grower diet had better overall weight gain (P < .01) than those fed the low-amino-acid diet. The rate of lean accretion was, however, similar between the two groups of pigs. Furthermore, pigs fed the low-amino-acid grower diet seemed to have better carcass quality, as indicated by less ultrasound backfat (P < .01) and larger carcass longissimus muscle area (P < .05). Average and 10th rib carcass backfat decreased linearly (P < or = .05) and lean accretion rate improved linearly (P < .05) as the amino acid content of finisher diets increased, but there was no grower x finisher diet interaction in these and other response criteria. Although no evidence of compensatory weight gain was observed, it is possible that compensatory lean tissue growth may have occurred in pigs subjected to early amino acid restrictions at the expense of fatty tissue growth.     

Effect of long-term feeding of graded levels of deoxynivalenol (DON) on growth performance,nutrient utilization,and organ health in finishing pigs and DON content in biological samples

The prevalence of deoxynivalenol (DON) is a concern for swine producers, and although there has been extensive research into the effects of DON in pigs, focus has been in young pigs and/or in short-term studies. The objective of the study was to determine the effect of long-term exposure to DON-contaminated diets in finisher pigs. A total of 200 pigs (76.6 ± 3.9 kg initial weight) were group housed (five pigs per pen; n = 10 pens/treatment) in a 6-wk trial. Pigs were fed a wheat-barley-soybean meal-based control (CONT) diet with no DON or the basal diet in which clean wheat was replaced by DON-contaminated wheat and wheat screenings to provide DON content of 1, 3, or 5 ppm (DON1, DON3, and DON5, respectively). Individual BW and pen feed intake were recorded weekly to calculate average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F). Blood was collected on days 0, 14, and 43 and analyzed for indicators of liver and kidney health. Nitrogen (N)-balance was conducted immediately following the growth performance period to determine the effect of DON on nutrient utilization. Blood and urine samples collected during N balance were analyzed for DON content. Feeding DON reduced (P < 0.05) ADFI and ADG from days 0 to 28 compared with CONT, after which there was no effect of diet on ADFI and ADG. The G:F was lower (P < 0.05) in DON5 fed pigs compared with all treatments during days 0 to 7; however, no treatment effects on G:F was observed from days 8 to 42. Nitrogen retention was lower (P < 0.05) in DON3 and DON5 compared with DON1-fed pigs. Nitrogen retention efficiency was higher (P < 0.05) in DON1 compared with DON3 and DON5 and protein deposition for DON1 pigs was higher (P < 0.05) than all treatments. There were no treatment effects on indicators of liver and kidney health. As dietary DON intake increased, concentration of DON in blood and urine increased. Overall, although there was an initial decrease in ADG and ADFI in pigs receiving diets containing >1 ppm DON, pig performance recovered after a period of time, whereas nutrient utilization continued to be affected after recovery of performance. Moreover, the lack of DON on G:F indicates that the negative effects of DON on growth performance are largely due to reduced feed intake. Overall, although pigs maybe capable of adapting to intake of DON-contaminated diets, their final body weight will be reduced when fed diets containing >1 ppm DON.     

Liquid diets accelerate the growth of early-weaned pigs and the effects are maintained to market weight

Piglets (n = 240, 11.0+/-0.1 d old, 3.93+/-0.05 kg) were allotted to one of four treatments in a 2 x 2 factorial arrangement to examine the effects of diet physical form and nursery environment during the first 14 d after weaning on growth to market weight. During the treatment period, pigs were housed (10 pigs/ pen) in either a conventional hot nursery (30 degrees C) or a segregated-temperature nursery (cool ambient temp. of 24 degrees C, with enclosed hot-box hovers at 32 degrees C). Pigs in each environment were fed nutritionally identical diets in either liquid or dry-pellet form for 14 d. Subsequently, all pigs were fed identical dry diets and were housed in common grower-finisher facilities (penned by sex, five pigs/pen). At the end of the treatment period (d 14), pigs fed the liquid diet were 21% heavier than pigs fed the dry pellet diet (9.22 vs 7.60 kg; P < 0.001). Similarly, gain, feed intake, and gain/feed of liquid-fed pigs were 44%, 18%, and 22% greater, respectively, than observed for pigs fed the dry pellet diet. No main effect of environment was observed (P > 0.10); however, an interaction with diet physical form occurred during the early-nursery period (P < 0.01). Pigs fed the liquid diet showed better performance in the conventional nursery, whereas pigs fed the dry pellet diet were favored in the segregated-temperature nursery. No major differences in growth performance or in ultrasound carcass measurements were detected during the growing-finishing period; however, the advantage in body weight of liquid-fed pigs gained during the first 2 wk postweaning was maintained to the end of the trial (113.9 vs 110.6 kg; P < 0.05). Pigs that were fed the early-nursery diet in liquid form reached market weight (110 kg) 3.7 d sooner than the dry-fed controls (P < 0.01). Estimates of lean gain (calculated from live ultrasound data) were unaffected, suggesting that composition of growth was not altered. Collectively, these results show that liquid feeding during early life can markedly accelerate piglet growth performance and that the growth advantage is maintained to market weight, with no evidence of compensatory gain in the dry-fed control pigs.     

Interactive effects of dietary calcium, phosphorus and copper on performance and liver stores of pigs

Three experiments involving 304 pigs were conducted to determine the related effects of copper (Cu), calcium (Ca) and phosphorus (P) on the performance and liver Cu stores of growing-finishing pigs. Rate and efficiency of gain were improved by the addition of 250 ppm of Cu to the diets. Improvements in rate of gain averaged 6.6% (652 vs 696 g/d) to 60.5 kg body weight and 1.7% (713 vs 725 g/d) to 94.5 kg body weight. Feed:gain ratio was improved by 1.4% to 60.5 kg and 1.6% to 94.5 kg body weight when Cu was added to the diet. Increasing the dietary Ca and P levels from .65% Ca and .55% P to 1.2% Ca and .86 or 1.0% P resulted in increased (P less than .01) growth rate to 60 and 95 kg (649 vs 699 g/d and 700 vs 737 g/d, respectively), but feed efficiency was not affected (2.86 vs 2.84 and 3.18 vs 3.17 kg feed/kg gain, respectively.) Feeding the higher Ca and P levels resulted in increased liver Cu levels in pigs fed 250 ppm Cu (189 vs 323 ppm), but Ca and P did not affect liver Cu of pigs fed low Cu diets (29 vs 28 ppm). When dietary Ca and P were varied independently, the high Ca level increased liver Cu, but P had little effect on liver Cu. Increasing the dietary P level partially alleviated the effect of Ca on liver Cu.     

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.