Efficacy of initial postweaning diet and supplemental coconut oil or soybean oil for weanling swine

Two experiments involving a total of 581 crossbred pigs weaned at 23 +/- 2 d of age evaluated 1) the efficacy of two diets that contained milk products during the initial 14 d postweaning and 2) the effect of coconut oil or soybean oil additions to swine starter diets. In Exp. 1, postweaning performance responses of pigs fed a control corn-soybean meal-dried whey (C-SBM-DW) diet without added fat were compared with those of pigs consuming diets that contained 3, 6, or 9% levels of coconut oil or degummed soybean oil. The results demonstrated no beneficial weight gain, feed intake, or gain-to-feed ratio response during the initial 14 d postweaning to either dietary oil source. From 15 to 35 d, gains increased to the 6% added fat level, but there was no effect on feed intake when the gain-to-feed ratio was improved to the 9% fat level. In Exp. 2, two diets containing milk products were fed during the initial 14-d postweaning period. The first diet contained corn, soybean meal, dried whey, dried skim milk, and fishmeal (high nutrient dense diet, HNDD), and the second was a C-SBM diet with 25% dried whey. During the period from 15 to 35 d, diets contained no added fat or a 6% level of coconut oil, soybean oil, or the 1:1 combination of each at 3%. The results demonstrated that for the postweaning period from 0 to 14 d pigs fed the HNDD had higher gains (P less than .01), feed intakes (P less than .01), and gain-to-feed ratios (P less than .01) than pigs fed the C-SBM-DW diet.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of diet complexity and dietary lactose levels during three starter phases on postweaning pig performance

Four experiments involving 1,005 crossbred pigs weaned at 19 +/- 2 d of age evaluated the effect of diet complexity and lactose level on starter pig performances. Experiment 1 was a randomized complete block (RCB) conducted in nine replicates with 135 pigs. A complex diet using several protein sources, a semicomplex diet with fewer protein sources, and a simple diet of corn and soybean meal comprised the three treatment groups. All diets contained 25% lactose (as-fed basis) with lysine (total) constant from d 0 to 14 (1.55%) and d 14 to 28 (1.45%), respectively. Gain, feed intake, and feed efficiency (P < 0.05) improved as diet complexity increased during both periods. In Exp. 2, 240 pigs in eight replicates in a RCB design were fed complex diets, but dietary lactose (total; as-fed basis) levels ranged from 10 to 35% in 5% increments from 0 to 14 d after weaning. From 14 to 30 d, a common 17% lactose diet was fed to evaluate the effects of early lactose level on subsequent responses. Gains (P < 0.05) increased for the 0- to 7- and 0- to 14-d periods as lactose increased to 30%. Similar gains resulted for all treatment groups from 14 to 30 d after weaning, with no evidence of compensatory responses to early lactose levels. In Exp. 3, 330 pigs were fed complex diets. From 0 to 7 d after weaning, the diets contained 25% lactose (as-fed basis), and from 7 to 21 d postweaning, the lactose levels ranged from 7 to 31% in 5% increments. Gain (P < 0.01) and feed efficiency (P < 0.05) increased from 7 to 21 d to the 17% lactose level. In Exp. 4, 300 pigs were fed 25 and 17% (as-fed basis) lactose diets from 0 to 7 and 7 to 21 d postweaning, respectively. From 21 to 35 d postweaning, lactose levels of 0 to 20% in 5% increments were added to a corn-soybean meal diet. The experiment was conducted as a RCB design in 12 replicates. Gain (P < 0.05) and feed intake (P < 0.05) increased to 10 to 15% lactose. When the data from Exp. 4 were partitioned into lighter (15.0 kg) and heavier (17.7 kg) pig weight replicates, only the lighter replicates had significant improvements in gain, feed intake, and feed efficiency (P < 0.05) in response to dietary lactose. These results demonstrated that starter pigs performed better when fed complex diets, that dietary lactose levels of 25 to 30% (to 7 kg BW) during the initial week postweaning, 15 to 20% lactose during d 7 to 21 (to 12.5 kg BW), and 10 to 15% lactose during d 21 to 35 postweaning (to 25 kg BW) resulted in maximum performance.     

Effect of protein and(or) carbohydrate fractions of dried whey on performance and nutrient digestibility of early weaned pigs

One hundred eighty 3-wk-old pigs (initial weight 4.8 kg) were utilized in a 35-d growth trial to determine the effects of the carbohydrate and(or) protein fraction of dried whey on pig performance. In addition, 30, 3-wk-old pigs (initial weight 4.9 kg) were used in two digestion trials to study the effects of the whey fraction on nutrient digestibility. Dietary treatments included a corn-soybean meal diet (control), control + 20% dried whey, control + 14.4% lactose, control + 2.1% lactalbumin, control + 14.4% lactose + 2.1% lactalbumin, and control + 8.4% whey protein concentrate. Pelleted diets containing equal lysine concentrations were fed. Lactose and lactalbumin were added at the same levels as provided by a 20% dried whey diet. Pigs fed diets containing milk products exhibited superior (P less than .05) ADG and efficiency of feed utilization and greater (P less than .05) apparent digestibilities for DM, energy and N compared with pigs fed the control diet. Including either lactose or lactalbumin in the diet for the early weaned pig resulted in similar gain, feed efficiency and nutrient digestibility. These results indicate that both the carbohydrate (lactose) and protein (lactalbumin) fractions of dried whey are important in explaining the beneficial response to dried whey elicited in the weanling pig.     

Feed additive studies with newly weaned pigs: efficacy of supplemental copper, antibiotics and organic acids

Six experiments involving 706 newly weaned 28- to 32-d-old pigs were conducted to evaluate the efficacy of copper (Cu) sulfate (to provide 250 mg/kg Cu), antibiotic-sulfa combinations [chlortetracycline, 110 mg/kg + penicillin, 55 mg/kg + sulfamethazine, 110 mg/kg; i.e., Aureo-Sulfa-Penicillin (ASP) or tylosin, 110 mg/kg + sulfamethazine, 110 mg/kg; i.e., Tylosin-Sulfa (TS)] and anhydrous citric or fumaric acid (.75 to 1.5% of the diet). The basal experimental diet was a 19% crude protein (CP)-fortified corn-soybean meal diet (1.08% lysine) containing 7% dried whey and 3% fish meal. Marked and consistent gain and gain/feed responses occurred from the Cu supplement, particularly during the first week postweaning. The antibiotic-sulfa combinations were less efficacious than Cu during the 1-wk postweaning stress period. During either the 1- or 3-wk growth periods, ASP and TS showed additivity with Cu in promoting rate and efficiency of weight gain. Liver Cu was increased by Cu addition to the diet, but neither ASP nor TS affected Cu deposition in the liver. In a factorial experiment involving 17% (1.01% lysine) or 20% CP (1.23% lysine) corn-soybean meal diets containing either no dried whey or an addition of 25% whey, Cu supplementation elicited marked improvements in rate and efficiency of weight gain, particularly in diets without added whey. Likewise, whey addition improved pig performance, especially when added to the diets containing no supplemental Cu.(ABSTRACT TRUNCATED AT 250 WORDS)     

日粮蛋白质来源对早期断奶仔猪胃内消化酶活性的影响

本试验将95头新生迪卡小公猪随机分为4组,第1、2、3组每组19头,均由两头经产母猪哺乳喂养,21日龄断奶。第4组仔猪38头,由4头经产母猪哺乳喂养,35日龄断奶。7日龄起至35日龄各组仔猪分别饲喂不同蛋白质来源的日粮。试验各组仔猪在24、28和35日龄进行屠宰试验,取胃内样品进行酶活性测定。试验结果表明:21日龄断奶使仔猪胃内蛋白酶、脂肪酶活性显著降低,酶活性在1周内不能得到完全恢复,胃蛋白酶活性可在断奶后2周得到恢复;全植物性蛋白日粮使早期断奶仔猪胃内蛋白酶和脂肪酶活性显著降低;日粮中加一定量乳清粉和动物性蛋白质饲料能有效提高胃蛋白酶和脂肪酶的活性。因此,断奶及日粮蛋白质来源显著影响早期断奶仔猪胃内消化酶活性。     

Interrelationship between hypersensitivity to soybean proteins and growth performance in early-weaned pigs.

The objective of this growth trial was to determine the interrelationship between immunological criteria, gut morphology, and performance of starter pigs fed soybean proteins processed by different methods. One hundred twenty-five pigs were orally infused with 6 g/d of either dried skim milk, soybean meal (48% CP), soy protein concentrate, extruded soy protein concentrate, or experimental soy protein concentrate from 7 to 11 d of age and then fed a diet containing the same protein sources from weaning (d 21) to 35 d of age. All pigs were fed a corn-soybean meal diet containing 10% dried whey, 1.25% lysine, and 3% soybean oil for the remaining 21 d of the experiment. Xylose absorption and anti-soy immunoglobulin G (IgG) titers were measured on d 6 postweaning, and skin-fold thickness after intradermal injection of protein extracts was measured on d 7 postweaning. A total of 25 pigs (five pigs/treatment) was euthanatized on d 7 postweaning. Villus height and crypt depth from duodenum samples were measured. These measurements were obtained to elucidate a relationship between the hypersensitivity responses to soybean products and growth performance of baby pigs. Pigs fed diets containing soybean meal had a lower (P less than .05) rate of gain (d 0 to 14) and villus height, higher (P less than .01) serum anti-soy IgG titers, and increased skin-fold thickness (d 6 and 7 postweaning) after intradermal injection compared with those fed dried skim milk. Pigs fed other soy proteins also had lower ADG from d 0 to 14 postweaning; however, pigs fed moist extruded soy protein concentrate tended (P less than .09) to have higher ADG and improved feed utilization when compared with pigs fed soybean meal (d 0 to 14).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of dietary phosphorus on selenium retention in postweaning swine

Two experiments were conducted to evaluate the effect of dietary Se and P levels on Se retention in postweaning swine. A 20% protein corn-soybean meal diet at two dietary Se levels (.3 and 5.0 ppm) and four total P levels (.50, .70, .90, 1.10%) were fed. Supplemental Se was provided from sodium selenite with inorganic P from dicalcium phosphate. In Exp. I, 151 pigs weaned at 4 wk of age were allotted by sex, litter and weight and fed their treatment diets for 28 d after a 7-d adjustment to a basal diet. Dietary Se level had no effect on performance measurements. As dietary P level increased, there was an increase in daily gain, feed intake and a decrease in feed to gain ratio. Dietary P resulted in similar plasma, longissimus muscle and kidney tissue Se values within each dietary Se level, while liver Se declined as dietary P level increased. Dietary P level had no effect on plasma, heart or liver glutathione peroxidase (GSH-Px) activity. In Exp. II, 32 barrows, after being fed their diets for a 28-d period, were placed in individual metabolism crates where a balance trial was conducted. Dietary P level reduced absolute and percentage Se retention, particularly at dietary P levels of .90 and 1.10%. Phosphorus retention was not affected by dietary Se. Neither dietary P nor Se level had any effect on N retention. These results suggest an effect of dietary P level on Se retention and liver Se, particularly at dietary P levels above the pig's P requirement, while the effect is minimal at or below the pig's P requirement.     

Efficacy of dried whey and its lactalbumin and lactose components at two dietary lysine levels on postweaning pig performance and nitrogen balance.

Two experiments were conducted to determine the efficacy of lactalbumin and lactose components of dried whey on gain and feed performance responses and N retention of weanling swine. In Exp. 1, a 2 x 5 factorial arrangement of treatments in a randomized complete block design in seven replicates was used to evaluate the efficacy of two dietary lysine levels (.90 and 1.30%) in 1) a corn-soybean meal (C-SBM) mixture, 2) C-SBM and 20% dried whey (C-SBM-DW), or the dried whey component replaced with 3 lactalbumin and cornstarch, 4) lactose and an amino acid mixture, or 5) the combination of lactalbumin and lactose. A total of 420 pigs weaned at 23 +/- 2 d of age, weighing an average of 6.87 kg BW, were used in a 3-wk experiment. Experiment 2 was a balance trial conducted as a 3 x 2 x 3 factorial arrangement in a split-plot design in three replicates. The negative (i.e., C-SBM) and positive (i.e., C-SBM-DS) control diets and the C-SBM-lactalbumin-cornstarch diets at the two lysine levels of Exp. 1 were the main plots, each evaluated for a 3-wk postweaning period. Growth rate (P less than .05), feed intake (P less than .01), N retention (P less than .01), and apparent N digestibility (P less than .05) were increased when pigs were fed the C-SBM-DW compared with the C-SBM diet.(ABSTRACT TRUNCATED AT 250 WORDS)     

Impact of energy intake and pregnancy status on rate and efficiency of gain and backfat changes of sows postweaning

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

Effect of dietary calcium on selenium retention in postweaning swine

Two experiments were conducted to evaluate the effect of dietary Se and Ca on Se utilization in postweaning swine. Two levels of dietary Se (.3 or 5.0 ppm) supplemented as sodium selenite and four levels of total dietary Ca (.50, .80, 1.10 or 1.40%) in a 20% protein, corn-soybean meal diet were evaluated. Inorganic Ca was supplied from dicalcium phosphate and limestone. In Exp. I, 135 pigs weaned at 4 wk of age were allotted by sex, litter and weight and fed a basal diet for 7 d and then their treatment diets for a 28-d period. Plasma and tissue were collected at the end of the trial for Se concentration and glutathione peroxidase (GSH-Px) activity. Dietary Ca had no effect on gain or feed measurements but 5.0 ppm Se depressed daily gain slightly. When 5.0 ppm dietary Se was fed, there resulted higher liver, kidney, heart and longissimus muscle Se concentrations than when .3 ppm was provided, but dietary Ca had no effect on tissue Se values within each dietary Se level. Plasma GSH-Px increased when higher dietary Se was provided, whereas neither heart nor liver GSH-Px activity was affected by dietary Se or Ca level. In Exp. II, a 5-d balance trial was conducted with 32 barrows after adjustment to their treatment diet for a 28-d period. Selenium retention increased quadratically as dietary Ca increased, whereas Ca retention was not affected by dietary Se. These results suggest that low dietary Ca levels may reduce total Se retention but not Se metabolism within body tissue.     

Effect of weaning, week postweaning and diet composition on pancreatic and small intestinal luminal lipase response in young swine

The effects of weaning, week postweaning and diet composition on concentration of lipase in the pancreas and small intestinal lumen were investigated in weanling swine. In Exp. 1, lipase levels were evaluated in suckling pigs from 2 to 35 d of age and in pigs weaned at 21 or 35 d of age. Pigs weaned at 21 d of age were fed a corn-soybean meal diet with lipase levels measured from 3 to 28 d postweaning. Pancreas weights increased during the suckling period; they were lowered at 3 d postweaning and were lower at 7 d postweaning than in suckling pigs but increased linearly from 3 to 28 d postweaning. Lipase level per unit wet tissue and total pancreatic levels increased from 2 to 35 d of age in suckling pigs (P less than .01). Weaning at 21 d of age resulted in a decline (P less than .05) in lipase levels in the pancreas at 3 and 7 d postweaning, but the levels subsequently tended to increase between 7 and 28 d postweaning. Whereas relative lipase levels in the intestinal lumen increased from 2 to 35 d of age in suckling pigs, total luminal enzyme did not decline upon weaning when pigs were weaned at either 21 or 35 d of age. Total luminal lipase per unit empty body increased linearly (P less than .01) each week postweaning. In Exp. 2, a 2 X 2 factorial arrangement of corn oil (0 or 6%) and dried whey (0 or 25%) was used to evaluate digestive lipase levels in pigs weaned at 21 d of age.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of graded levels of lysine and excess arginine and threonine on young pigs fed practical diets

Three experiments were conducted to estimate the lysine requirement of the weanling pig and the effects of excess arginine and threonine on that estimate. Feeding 1.15% dietary lysine in Exp. 1 and 1.20% in Exp. 2 maximized feed efficiency and resulted in the lowest plasma urea N values. Adding .15% threonine to the diets in Exp. 2 did not affect (P greater than .10) performance of the pigs, but increased (P less than .01) plasma urea N and decreased (P less than .01) plasma lysine concentrations. Supplemental arginine (.22%) did not affect performance of the growing pigs in Exp. 3, but it increased (P less than .01) plasma urea N. Pigs fed a corn-soybean meal diet utilized feed more efficiently (P less than .05) than those fed a corn-fish meal-dried whey diet. The most likely cause for this response was that the corn-soybean diet contained more lysine (.82%) than expected, whereas the corn-fish meal-dried whey diet had close to the expected content of lysine (.72%). From these results, it was concluded that the lysine requirement of the weanling pig fed practical diets is at least 1.15 or 1.20% of the diet. Also, added arginine or threonine did not adversely affect the performance of pigs.     

Evaluation of various extracted vegetable oils, roasted soybeans, medium-chain triglyceride and an animal-vegetable fat blend for postweaning swine

A total of 280 crossbred pigs weaned at 21 d of age and weighing approximately 6 kg were utilized in five replicates to evaluate pig growth responses when fed a basal diet or one of several dietary lipid sources during a 4-wk postweaning period. A basal corn-soybean meal-corn starch-dried whey diet was compared with diets supplemented at a 7.75% level with one of the following lipid sources: corn oil, coconut oil, soybean oil, medium-chain triglyceride (MCT) or an animal-vegetable blend. A sixth treatment evaluated a roasted soybean diet formulated to an energy:lysine level equivalent to that of the fat-supplemented diets. In Exp. II, 36 crossbred weanling barrows were used to determine apparent fat and N digestibilities when soybean oil, roasted soybean, coconut oil or the MCT-supplemented diets were fed. Although pigs fed coconut oil grew somewhat faster, fat inclusion generally did not increase pig growth rate or result in lowered feed intake during the initial weeks postweaning; during the latter portion of the starter phase the addition of dietary fat resulted in a higher growth rate but feed intake was unaffected, resulting in an overall improvement in feed-to-gain ratio (P less than .05) for all but the roasted soybean diet. Pigs fed coconut oil had higher serum triglyceride and lower serum urea concentrations than did pigs fed diets containing most other lipid sources. Pigs fed MCT and coconut oil diets had a higher (P less than .01) apparent fat digestibility during the initial 2 wk postweaning than pigs fed soybean oil or roasted soybean diets. Pigs fed MCT and roasted soybeans had poorest growth rates; apparent fat and N digestibilities were lowest (P less than .05) for the roasted soybean diet.     

Effect of biotin and(or) lysine additions to corn-soybean meal diets on the performance and nutrient balance of growing pigs

Supplementation of a basal corn-soybean meal diet with 0 or .2% L-lysine and 0, .25 or .55 ppm biotin produced six dietary treatments in a factorial arrangement. Pig performance, post-weaning scour scores, plasma urea N (PUN) levels, N and energy balance and liver pyruvate carboxylase activity (PC) were response criteria. Crossbred pigs were fed from weaning at 4 wk of age (8.0 kg) to market weight in performance trials utilizing 552 pigs in the 35-d starter period and 384 pigs in the subsequent grower (about 21 to 50 kg) and finisher (about 50 to 95 kg) periods. Pigs remained on their respective dietary treatments for the entire experiment. Energy and N balance trials were conducted utilizing 36 barrows from the grower period (avg 44.7 kg) and 36 barrows from the finisher period (avg 90.3 kg) of the performance study. Barrows were sacrificed following completion of the 6-d collection periods to measure liver PC activity. The basal starter diet contained 17.0% crude protein (CP), 86% lysine and .22 ppm biotin. Increasing the corn:soybean meal ratio reduced the dietary levels of CP, lysine and biotin to 14.8%, .69% and .19 ppm for the basal grower diet and to 11.1%, .50% and .17 ppm, respectively, for the basal finisher diet. Lysine supplementation improved (P less than .05) average daily feed intake and average daily gain for all periods, gain:feed ratios for the starter and grower periods and reduced (P less than .01) PUN levels at the end of the starter and finisher periods.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of inorganic selenium supplementation on selenium retention in postweaning swine

A total of 64 weanling pigs was used in a randomized complete-block experiment to evaluate the efficacy of various inorganic Se levels on weekly Se balance measurements over a 5-wk post-weaning period. Four-week-old weaned pigs were fed a 20% protein, corn-soybean meal diet supplemented with 0, .3, .5 or 1.0 ppm Se from sodium selenite. Eight pigs were allotted by weight, litter and sex to each metabolism crate. A 2-d preliminary period followed by a 5-d collection period was conducted for five weekly periods. Feed intake was provided ad libitum but was similar between dietary Se levels. Fecal Se excretion increased each week and with increasing dietary Se level. Apparent digestibility of Se was relatively constant for each period when inorganic Se was fed, averaging approximately 70%, whereas it ranged between 30 to 40% for pigs fed the basal diet during wk 2 through 5. Urinary Se decreased during the postweaning periods for pigs fed the basal diet, but increased linearly as dietary Se increased during the initial 2-wk postweaning period and then quadratically during wk 3 through 5. There was a net loss of Se from the body when the Se-unsupplemented basal diet was fed during the initial 2 wk postweaning, whereupon, it became positive. Selenium retention in pigs supplemented with inorganic Se increased each week of the trial. When Se retention was expressed in relation to Se intake, the resulting regression was linear (R2 = .99), suggesting that Se retention in the postweaning pig increased in direct proportion to the amount consumed when diets contained up to 1.0 ppm Se.     

早期断奶仔猪日粮中适宜蛋白质及赖氨酸水平的研究

本试验采用玉米—豆粕—鱼粉型日粮,研究不同蛋白质和赖氨酸水平对仔猪生长性能及小肠粘膜组织形态的影响。试验采用２５±３日龄断奶仔猪７２头,按２×３因子水平试验设计,即两个蛋白质水平（１８％,２０％）和三个赖氨酸水平（１．０％,１．３％,１．６％）,分为６个处理,每个处理设３个重复,试验期为２８天。于试验第１１天,每个重复选取一头仔猪,屠宰后取小肠组织样品,测定小肠各段的粘膜厚度、绒毛高度及隐窝深度。结果表明：在本试验条件下,仔猪断奶后的营养水平应分阶段供给：断奶早期,即仔猪日龄为２５～３５天、体重为６．７８～８．９２ｋｇ时,宜采用较高营养水平,即粗蛋白２０％和赖氨酸１．３％;断奶后期,即仔猪日龄为３６～５３天、体重为８．９８～１７．５２ｋｇ时,可采用较低营养水平,即粗蛋白１８％和赖氨酸１．０％;高蛋白水平导致小肠绒毛缩短及隐窝加深（Ｐ＜０．０５）,有提高仔猪腹泻率的趋势。     

Effect of evening or morning weaning and immediate or delayed feeding on postweaning performance of pigs.

Weanling pigs (n = 176), 21 to 26 d of age (average initial weight, 7.1 kg), were used to evaluate the effects of weaning time (evening vs morning) and feeding time (immediate vs delayed) on postweaning performance. Pigs were randomly allotted within litters to four treatments in a 2 x 2 factorial arrangement as follows: 1) weaning at 2000 with immediate feeding, 2) weaning at 2000 with 12-h delayed feeding, 3) weaning at 0800 with immediate feeding, and 4) weaning at 0800 with 12-h delayed feeding. A 12:12 light:dark photoperiod was maintained. Four pigs were held per pen, and all pigs were given ad libitum access to a 20% CP corn-soybean meal diet with 15% dried whey throughout the 28-d study. The interactions between weaning and feeding times were not significant. During the 28-d period, pigs weaned at 2000 consumed 5% more feed (P less than .10) and grew 6% faster (P less than .05) than pigs weaned at 0800. Feed to gain ratios were similar for both time treatments. Variance of ADG within pens as measured by range, logarithm of variance, and CV were generally smaller for pigs weaned at 2000 than for pigs weaned at 0800 with no effect of feeding time. Pigs fed immediately after weaning and those delayed for 12 h had similar overall feed consumption, ADG, and feed to gain ratios. Weaning pigs in the evening enhanced performance, perhaps by better matching the normal diurnal eating and activity patterns and weaning time.     

Effects of dietary dried whey and corn oil on weanling pig performance, fat digestibility and nitrogen utilization

Two experiments were conducted to evaluate the effects and interactions of dietary levels of corn oil (0 vs 6%) and dried whey (0 vs 25%) on performance of young pigs during a 4-wk postweaning period. The first experiment, conducted in five replicates as a 2 x 2 factorial in a randomized block design, evaluated gain and feed intakes of 172 pigs weaned at 21 d of age. Pigs were bled at weekly intervals, and samples were assayed for serum triglyceride and urea concentrations. In a second experiment, 36 barrows in three replicates were used to evaluate the same treatments on apparent digestibility and absorption of fat and N retention during each week of a 4-wk postweaning period. The dietary inclusion of dried whey resulted in greater gains and feed intakes and reduced feed-to-gain ratios during each week of the postweaning period, with the largest relative improvement occurring during wk 1. Supplemental corn oil did not enhance pig gains the first 3 wk postweaning, but response improved by wk 4. Feed intakes were slightly (P less than .10) lower when corn oil was provided. The inclusion of corn oil resulted in an improved feed-to-gain ratio (P less than .01), particularly evident during wk 3 and 4 postweaning. Neither gain nor feed utilization were improved by added corn oil during the initial 2-wk postweaning period regardless of dried whey addition. Apparent digestibilities of fat were unaffected at each weekly interval by dietary dried whey inclusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of a biological response modifier: effects on starter pig performance

The influence of a biological response modifier (FK-565) on weanling pig performance was evaluated. One hundred twenty-five weanling pigs (weaned at 21 +/- 3 d) averaging 6.3 kg were utilized in a 35-d growth trial. Dietary treatments included a basal diet (1.25% lysine, corn-soybean meal-dried whey), the basal plus .1, 1 or 10 ppm FK-565 and the control plus an antibacterial combination containing chlortetracycline, sulfamethazine and penicillin. Performance was recorded weekly, and on d 35 all pigs were bled for whole blood and serum chemistry profiles and then were euthanatized. Heart, liver, kidneys and spleen weights were recorded. Also, gross and histological examinations were made of these organs, as well as sections of lung, ileum, bone marrow, thymus and mesenteric lymph node. By d 14, pigs fed the antibacterial diet gained faster (P less than .06) than pigs fed the control and FK-565 diets. However, no differences (P less than .10) in feed intake at d 14 or efficiency of feed utilization at either d 14 or 35 were observed. For the overall 35-d trial, ADG was greater (P less than .01) for pigs consuming the antibacterial diet than for pigs consuming control and the FK-565 diets. Pigs consumed more of the antibacterial diet than of the other diets (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)     

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)