Effect of different dietary levels of natural-source vitamin E in grow-finish pigs on pork quality and shelf life.

Improving pork quality and shelf life is important in today's swine industry because higher levels of DDGS are incorporated into pig diets. Relatively high level of poly-unsaturated fatty acids (PUFA) in DDGS may increase pork susceptibility to lipid oxidation and thus reduce pork shelf life. Antioxidants such as vitamin E may delay the onset of pork lipid oxidation when used as an ingredient in the diet. This experiment examined carcass characteristics, meat quality, shelf life, and color stability in pork from pigs (n=150) fed five levels of a natural vitamin E (Nova-E) and one level of synthetic vitamin E. Natural vitamin E and synthetic vitamin E had no effect on carcass characteristics or meat quality. Increasing dietary natural vitamin E from 10 to 200mg/kg decreased lipid oxidation. Lipid oxidation of pork chops and ground pork was similar between pigs fed 40mg/kg and higher levels of natural vitamin E, indicating no additional benefits from supplementing beyond 40mg/kg natural vitamin E. Supplementing 200mg/kg synthetic vitamin E decreased pork lipid oxidation when compared to supplementing 10mg/kg natural vitamin E. High levels of natural vitamin E or synthetic vitamin E, however, did not prevent discoloration of loin chops. These data indicate that natural vitamin E was effective to help reduce lipid oxidation and the effective minimal level of dietary supplementation appeared to be 40mg/kg.

Amino acid availability and true metabolizable energy content of corn distillers dried grains with solubles in adult cecectomized roosters.

Five sources of corn distillers dried grains with solubles (DDGS), which varied in darkness of color, were collected from several processing plants in the Midwestern United States. Sources of DDGS were analyzed for their amino acid and energy contents, measured for color score, and evaluated for TMEn, apparent amino acid digestibility, and true amino acid digestibility. A precision-fed rooster assay was used, in which each DDGS sample was tube fed (25 g) to adult cecectomized roosters, and the excreta were collected for 48 h. The experiment was conducted as a randomized complete block design with 8 replicates. Seven adult roosters (averaging 75 wk of age) were used in each period, with 5 fed the DDGS sources and 2 fasted to estimate basal endogenous amino acid losses. One source (no. 5) was the darkest, 2 sources (no. 2 and 4) were light, whereas 2 other sources (no. 1 and 3) were intermediate in color as measured by a colorimeter. Total lysine content of the DDGS sources ranged from 0.48 to 0.76%, with the lowest lysine content in the darkest DDGS source. Apparent and true lysine digestibility was approximately 30 and 15 percentage units lower (P < 0.05), respectively, in the dark-colored source (no. 5) than in the other 4 sources. Average apparent and true digestibility of the essential amino acids were 10 and 8 percentage units lower (P < 0.05), respectively, in source 5 than the other 4 sources. The TMEn content of the 5 DDGS sources was also lower (P < 0.05) in the darkest DDGS (no. 5). Our results suggest that when the color score of a DDGS source, as measured by a colorimeter, reached a certain threshold (lightness between 28 and 34), amino acid availability and true metabolizable energy content may be reduced. This reduction was particularly evident for lysine, which had the lowest digestibility in the darkest DDGS source. These results suggest that dark-colored DDGS may have been overheated during drying, causing Maillard reactions to be more extensive and resulting in a lowered total lysine content, lysine digestibility, and TMEn content.

Essential and nonessential amino acid compositions of the total litter and individual fetal pig content and accretion rates during fetal development.

The AA requirements of reproducing females are likely influenced by genetics, number of embryos and fetuses, and their nutritional needs during development. Hence, it is important to determine the change in AA concentration during development. Fetuses from a total of 26 second-parity sows were used to determine their AA composition at various stages of pregnancy. Yorkshire × Landrace sows were bred to Duroc boars and killed at 45, 62, 80, and 100 d of gestation, and fetal weights were determined. The pigs from 6 litters were killed prior to nursing the sow. The number of fetuses ranged from 10 to 13 pigs/litter. Pigs were combined by litter, ground, and freeze-dried, and AA was determined by gas chromatography. Litter was the experimental unit, and statistics were conducted using the GLM model of SAS with the best fitting regression equation estimates for each AA determined. Individual pigs (average/litter), litter, grams per 100 g total AA, and the ratio of each AA to Lys were statistically determined. Although the regression of individual pigs and litters were significant in a quadratic, cubic, or quartic manner ( < 0.01 to < 0.05), the general trend was a quadratic increase in total essential AA (EAA) and nonessential AA (NEAA) from 45 d to birth. All AA increased rapidly from 80 d of gestation, and more than 50% of total fetal growth occurred from 80 d to birth. Three AA (Arg, Leu, and Lys) constituted more than half of the total EAA from 80 d of gestation to birth compared with the other EAA. Overall, the NEAA increased more rapidly as pregnancy progressed than the EAA, with Pro, Hyp, and Gly increasing at a faster rate. When expressed in a ratio of Lys to the other AA, both Arg and Leu had a greater ratio increase than Lys. These results demonstrated that 50% of the total amount of EAA in the fetal pig increased during the last 2 wk of gestation and that Arg and Leu increased at a greater rate than Lys. The NEAA increased at a faster rate than the EAA throughout pregnancy.

Evaluating dietary adjustment and collection times for total tract digestibility of Ca, P, and the essential microminerals with grower swine.

An experiment was conducted to determine 1) the length of time necessary for grower pigs to adjust to a new diet and 2) the consistency in excretion of urine and feces in 4 consecutive 5-d collection periods. The total tract excretion and digestibility values for Ca, P, and the essential microminerals were evaluated. The experiment was conducted in 6 replicates as a randomized complete block design. Pigs were fed a pretest diet from 20 to 40 kg BW that met the requirements. At 40 kg, 12 barrows were allotted to stainless-steel metabolism crates, where they continued being fed the pretest diet for a 7-d period for adjustment purposes. Treatment diets were then fed for the following 20-d period in four 5-d intervals. Treatment diets were a corn-soybean meal mixture and contained either 1) reduced Ca and P levels and no added microminerals (LOW) or 2) a diet with elevated Ca and P levels and supplemental microminerals that exceeded the pig's requirements (HIGH). The study collected urine and feces. Markers were added to the ration at the start of each period to distinguish between test intervals. Feces and urine were collected daily, frozen, and composited for each period. Analysis of diets and excrement was conducted using inductively coupled plasma mass spectrometry technology. In all cases, the excreted minerals and digestibility values were greater ( < 0.01) for the macrominerals when the HIGH diet was fed, whereas the digestibility values for the microminerals were often lower when the HIGH diet was fed. The macrominerals Ca and P both had consistent urine and fecal values for each of the final 3 collection periods within diet. The micromineral values were generally consistent for each 5-d collection period but varied between periods for several microminerals. These results indicate that a 5-d adjustment period was adequate for pigs to adjust to the treatment diets. A 5-d collection period was adequate for Ca and P, but the micromineral excretion and digestibility values were more variable, and a collection period of 10 d might be warranted. The results also indicated that the innate microminerals had a higher digestibility and bioavailability than thought previously and their digestibility is greater than that of inorganic microminerals. Thus, these results indicate that the innate microminerals should be an important factor in establishing the micromineral requirements for growing pigs.

Evaluating the influence of National Research Council levels of copper, iron, manganese, and zinc using organic (Bioplex) minerals on resulting tissue mineral concentrations, metallothionein, and liver antioxidant enzymes in grower-finisher swine diets.

Graded levels of a trace mineral premix containing an organic (Bioplex) source of Cu, Fe, Mn, and Zn was evaluated with additional treatments containing organic Zn or Fe. Grower-finisher pigs were fed from 25 to 115 kg BW. The number of pigs in the experiment, the breeding/genetics of the pigs, the management, and the average age of the pigs were previously reported. The experiment was conducted as a randomized complete block design in 7 replicates. Treatments were 1) basal diet without supplemental Cu, Fe, Mn, and Zn; 2) basal diet + 2.5 mg/kg Cu, 50 mg/kg Fe, 1.5 mg/kg Mn, and 40 mg/kg Zn (50% NRC); 3) basal diet + 5 mg/kg Cu, 100 mg/kg Fe, 3 mg/kg Mn, and 80 mg/kg Zn (100% NRC); 4) basal diet + 25 mg Zn/kg; 5) basal diet + 50 mg Zn/kg; and 6) basal diet + 50 mg Fe/kg. Selenium and I were added to all diets at 0.3 and 0.14 mg/kg, respectively. Diets were composed of corn-soybean meal, dicalcium phosphate, and limestone with phytase added to enhance mineral availability. Three pigs per pen were bled at 55, 80, and 115 kg BW and plasma was analyzed for microminerals. When the average replicate BW was 115 kg, 3 pigs per pen of an equal gender ratio were killed. The liver, kidney, and heart were removed and analyzed for microminerals. Liver, duodenum, and jejunal metallothionein and the antioxidant enzymes in the liver containing these microminerals were determined. The results demonstrated that plasma minerals were unaffected at the 3 BW intervals. Liver and duodenum metallothionein protein were greater ( < 0.05) as dietary micromineral levels increased but jejunum metallothionein did not change as microminerals increased. The activity of Cu/Zn superoxide dismutase (SOD) was not affected as the levels of the micromineral increased, whereas the activity of Mn SOD increased slightly ( < 0.05) to the 50% NRC treatment level. Liver Zn (relative and total) increased ( < 0.05) as dietary micromineral levels increased and also when Zn was added singly to the diet. Liver, kidney, and heart Cu and Mn concentrations were similar at the various micromineral levels. The activities of liver enzymes containing graded levels of Zn were not affected by dietary microminerals at 115 kg BW. These results indicate that the supplemental levels of Cu, Fe, and Mn were not necessary for grower-finisher pigs and that these innate microminerals in a corn-soybean meal diet were adequate, whereas a need for supplemental Zn was demonstrated.

Isolation, characterization, and developmental expression of pig intestinal fatty acid-binding proteins.

The goal of this study was to characterize and quantify intestinal fatty acid-binding proteins of the pig. Small intestinal mucosa from 13-19 kg pigs was homogenized and centrifuged to obtain cytosol. Isolation of fatty acid-binding proteins from delipidated cytosol was achieved using molecular sieve, oleic acid affinity, and ion exchange chromatography. Fatty acid-binding protein isolation was monitored using a fatty-acid binding assay in conjunction with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. Antisera to rat liver-fatty acid-binding protein cross reacted with an isolated intestinal fatty acid-binding protein of Mr = 13,000, whereas antisera to rat intestine-fatty acid-binding protein was not cross reactive with isolated pig intestinal proteins. These experiments identify a pig intestinal fatty acid-binding protein that exhibits strong immunochemical similarity to rat liver-fatty acid-binding protein. Cytosol prepared from intestinal mucosa of pigs at -4, 2, 4, 7, 15, 22, 28, and 35 d of age was assayed for fatty acid-binding protein activity. Preweaning fatty acid-binding protein activity in cytosol was maximal at 7 days of age when expressed as total jejunal fatty acid binding per kilogram bodyweight, intestinal or mucosal weight or milligram total protein. After weaning (21 d), fatty acid-binding protein activities declined to 28 days, but increased again by 35 days. Total soluble fatty acid-binding protein activity in pig intestine is regulated during postnatal development and this may account in part for the altered intestinal absorption of lipids observed in young pigs at weaning.

Effect of weight, split-weaning, and nursery feeding programs on performance responses of pigs to 105 kilograms body weight and subsequent effects on sow rebreeding interval.

An experiment using a total of 288 crossbred pigs from sows of two parties (1 or 3) were used in a 2 x 2 factorial arrangement of treatments in a randomized complete block design conducted in 12 replicates to evaluate pig weight and split-weaning on performance response to 105 kg BW. Pigs were allotted to two weight groups (4.1 to 5.5 kg or 6.8 to 8.2 kg) at 23 d of age and weaned at two ages (23 or 30 d). The lightweight pigs weaned at 23 d were fed a high-nutrient-dense diet (HNDD) for a 2-wk period, whereas those weaned at 30 d were fed the HNDD for 1 wk. Both groups were fed a corn-soybean meal-dried whey (C-SBM-DW) and a C-SBM diet, each for a 2-wk period. The heavyweight group weaned at 23 d was fed the HNDD for 1 wk, followed by the C-SBM-DW and C-SBM diet, each for 2 wk, whereas those weaned at 30 d were fed the C-SBM-DW diet and the C-SBM diet, each for 2 wk. From 20 to 105 kg, pigs of all groups were fed C-SBM diets that met or exceeded nutrient requirements. Sows that lactated for the additional week had litters of four pigs and were allowed to consume a 15% CP lactation diet ad-libitum, whereas sows weaned at 23 d were fed 1.8 kg/d of a 14% CP diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of dietary vitamin E on sow reproductive performance over a five-parity period.

A study involving 360 farrowings over a five-parity period evaluated the effects of dietary vitamin E on sow reproductive performance and the subsequent effects on serum, colostrum, and milk tocopherol contents. The 2 x 3 split-split-plot experiment was conducted at two locations that differed in the type of facility (indoor gestation pens/farrowing crates [IP/FC] or outside gestation lots/indoor farrowing pens [OL/FP]) and three dietary levels of dl-alpha-tocopheryl acetate (22, 44, or 66 IU/kg of diet), with five parities nested within sow in a repeated measure design. Sow serum alpha-tocopherol, Se, and glutathione peroxidase (GSH-Px) activity were measured at 30 and 90 d postcoitum and at 21 d postpartum (weaning) during each parity. Colostrum and 7-, 14-, and 21-d milk samples were analyzed for alpha- and gamma-tocopherol and Se concentrations. Three pigs per litter were bled at weaning and their serum was analyzed for alpha-tocopherol and Se concentrations and GSH-Px activity. The results indicated that sow weights and daily lactation feed intakes or litter birth and weaning weights were not affected by dietary vitamin E levels provided to the sow. There was an increased number of pigs born (total, P < .01; live, P < .10) when dietary vitamin E was increased. The incidence of mastitis, metritis, and agalactia decreased (P < .05) as dietary vitamin E was increased. The incidence of mastitis, metritis, and agalactia decreased (P < .05) as dietary vitamin E increased was higher (P < .05) with first- and second-litter sows, and was higher (P < .01) at the location that had the OL/FP facility. Colostrum and milk alpha-tocopherol increased (P < .01) as dietary vitamin E increased. Milk alpha-tocopherol declined linearly (P < .01) from 7 to 21 d postpartum in a parallel manner between dietary vitamin E levels. At weaning, pig serum alpha-tocopherol increased (P < .01) as sow dietary vitamin E level increased. These results support a higher dietary level of vitamin E than currently recommended by NRC (1988) for both gestating and lactating sows.

Assessment of the influence of dietary vitamin E on sows and offspring in three parities: reproductive performance, tissue tocopherol, and effects on progeny.

Sixty crossbred (Yorkshire-Hampshire X Duroc) gilts were fed one of four corn-soybean meal diets fortified with .3 ppm Se and 0, 16, 33, or 66 IU of DL-alpha-tocopheryl acetate/kg. The study was conducted over a three-parity period to evaluate sow reproductive performance and the vitamin E tissue status of both sows and progeny at various time periods postcoitum and(or) postpartum. The basal diet averaged 8.4 mg of alpha-tocopherol/kg and .38 ppm of Se. Although litter size at birth was lowest (P less than .15) when sows were fed the basal diet, a higher incidence of agalactia when sows were fed the lower dietary vitamin E levels resulted in an increased (P less than .05) litter size at 7 d postpartum as dietary vitamin E increased. Sow serum alpha-tocopherol increased (P less than .01) at each measurement period as dietary vitamin E level increased. Colostrum and milk alpha-tocopherol concentrations increased (P less than .01) as dietary vitamin E level increased, and colostrum values were three to five times higher than at later milks. Colostrum alpha-tocopherol declined by parity from sows fed less than or equal to 16 IU/kg but was similar at each parity for sows fed greater than or equal to 33 IU/kg, resulting in a dietary vitamin E x parity interaction (P less than .01). The Se content of sow milk declined with parity but was not affected by dietary vitamin E level. Sow liver tocopherol at weaning (28 d postpartum) increased (P less than .01) as dietary vitamin E increased and increased with parity (P less than .05). Pig serum and liver alpha-tocopherol concentrations were elevated at birth and 7 and 28 d of age as sow dietary level of vitamin E increased. Upon weaning, pigs were fed a torula yeast-dextrose diet that contained 3.0 mg of alpha-tocopherol/kg and .32 ppm Se for a 28-d postweaning period. Liver and serum alpha-tocopherol concentrations declined during the postweaning period. Evidence of the vitamin E deficiency occurred at 28 d postweaning in the progeny from sows fed the basal diet or 16 IU of vitamin E; the incidence was more prevalent in the pigs from Parities II and III. These results suggest that a supplemental level of 16 IU of vitamin E/kg of diet was inadequate for the reproducing sow; higher levels are justified, particularly when females are retained in the herd for several parities.

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)

Relationship of gestation protein and feed intake level over a five-parity period using a high-producing sow genotype.

High-producing Landrace-Large White crossbred gilts (n = 50) involving 198 farrowings were used to evaluate dietary gestation protein (13 vs 16% CP) and gestation feed intakes (Control vs High), and their interaction, over a five-parity period on sow reproductive performance. Gestation feed intake for Control was 1.81 kg/d during parity 1, increasing by .09 kg for each successive parity. The daily feed intake for High was greater by .13 kg or approximately 450 kcal ME at each respective parity. The experiment was a 2 x 2 in a randomized complete block design conducted in two replicates with parity nested within sow groups. Sow weights and backfat thickness were determined at various intervals. A lactation diet containing .90% lysine in parity 1 and .80% lysine during parities 2 to 5 was fed to all sows from farrowing to weaning (21 d). Sow and pig weights, feed intakes, and colostrum and 21-d milk samples were collected during each lactation. The High feed intake and the 13% protein diet resulted in greater (P < .01) backfat thicknesses, and the effects were additive. Backfat thickness declined quadratically (P < .01) by parity and from late gestation to the rebreeding period of the following parity. The High feed intake resulted in a larger litter size (P < .01), whereas dietary gestation protein concentration had no effect on parturition performance. Sows in each parity consumed more (P < .01) feed from 0 to 7 d postpartum and for the overall 21-d lactation period (P < .01) for parity 1 when the 16% gestation protein had been fed. Gestation feed intake regimens did not affect lactation feed intake. Neither gestation variable affected colostrum or 21-d milk fat, but concentrations declined (P < .01) in all groups after parity 2. Parity 1 litters were heavier at 14 and 21 d, with larger litter gains from 0 to 14 and 0 to 21 d when gestating sows had been fed the 16% protein and the High feed intake combination compared to the other sow treatment groups. From parity 2 to 5, litter weights and gains were similar for all treatment groups. This resulted in a three-way interaction response (P < .05) for these variables. These results suggest that primiparous sows required a greater gestation protein concentration and greater feed intake than generally recommended, but the 13% CP diet at the High feed intake was effective in older sows.

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.

Dietary calcium and phosphorus levels for weanling swine.

Two experiments were conducted, involving 440 weanling pigs, to determine the dietary Ca and P requirements from 7 to 20 kg body weight. All diets were formulated to 20% protein from corn and soybean meal; dicalcium phosphate and limestone were used as the inorganic mineral sources with the amounts varied to meet the total dietary concentration of either mineral evaluated. In the first experiment pigs were fed five dietary Ca treatment levels ranging from .50 to 1.30% in .20% increments, while dietary P was maintained at .70%. In the second experiment (a 2 X 5 factorial) dietary Ca was provided at either .70 or .90%, while P levels ranged from .50 to .90% in .10% increments. Blood samples were collected at approximately the midpoint and end if each experiment with bones collected for ash determination at the termination of the trial. In the first study dietary Ca level did not influence gain or feed intake but did increase the feed to gain ratio as Ca increased. Mineralization of the femur, rib and humerus bone plateaued at .80% dietary Ca. In the second experiment, dietary P influenced pig gain and feed intake with a plateau at the .60% dietary P level. Serum P also plateaued at dietary P levels of .60%. Linear regression breakpoint analyses of bone ash averaged .68% P. These results suggest that the total dietary Ca and P concentration necessary for weanling pigs to attain maximum bone ash from 7 to 20 kg body weight is .80 and .68%, respectively, with corn and soybean meal based diets; whereas .1% less P is needed to maximize performance traits. The young weanling pig's calculated available P requirement is approximately .35%.

Effect of organic and inorganic selenium sources and levels on sow colostrum and milk selenium content.

A study was conducted to evaluate the short-term effects of feeding two dietary Se sources at various Se levels on the transfer of Se to the dam's milk and nursing pig. Six dietary treatments were arranged in a 2 x 2 factorial arrangement with two additional treatments in a randomized complete block designed experiment. Inorganic (sodium selenite) or organic (Se-enriched yeast) Se sources were added to the diet at .15 or .30 ppm Se. A non-Se-fortified corn-soybean meal basal diet served as a negative control, and a sixth group was fed .15 ppm Se from both inorganic and organic Se sources. A total of 43 sows were fed their treatment diets at 2.2 kg/d from 6 d prepartum to parturition and at full feed through a 14-d lactation period. Ten sows were initially bled at 6 d prepartum, and three sows and three pigs from their litters were bled at 7 and 14 d postpartum. Serum was analyzed for its Se concentration and glutathione peroxidase (GSH-Px) activity. Colostrum was collected within 12 h postpartum and milk at 7 and 14 d of lactation. When the basal diet was fed, sow serum GSH-Px activity declined from 6 d prepartum and remained low throughout lactation. When dietary Se levels increased, sow serum Se concentration and serum GSH-Px activity increased (P < .05) at both 7 and 14 d postpartum. The short-term feeding of either Se source at .15 or .30 ppm Se did not affect colostrum Se content when inorganic Se was fed, but it was increased when organic Se was provided. This resulted in a significant Se source x Se level interaction (P < .01). Milk Se at 7 and 14 d postpartum was 2.5 to 3 times higher when the organic Se source was provided and resulted in a significant Se source x Se level interaction (P < .05). When the combination of inorganic and organic Se was fed at .15 ppm Se, colostrum and milk Se contents were similar to those of sows fed .15 ppm Se from the organic Se source. Pig serum GSH-Px activity was not affected at 7 and 14 d of age by dietary Se level or Se source fed to the sow, but serum Se increased (P < .05) as dietary Se level increased, particularly when sows had been fed organic Se. The results demonstrated that organic Se increased milk Se content more than did inorganic Se and increased the nursing pig's serum Se. These results indicate that inorganic Se was more biologically available for sow serum GSH-Px activity, but organic Se was more effectively incorporated into milk.

Mineral nutrition of the sow: a review.

The sow varies greatly in her mineral requirements, which largely reflects the nutritional demands during different phases of her reproductive cycle. Minerals are required for conceptus product formation, mammary secretions, and growth and maintenance. Although the sow's mineral requirements are highest during late gestation and lactation, those that are supplied from the diet and tissue reserves both contribute in meeting these nutritional needs. The sow is fairly resilient to borderline mineral insults, but longevity in the herd may be compromised under these conditions. Specific mineral deficiencies vary, but the reproducing sow will deplete the pool of tissue minerals before litter size, congenital abnormalities of developing fetuses or milk mineral composition are affected. Inadequate mineral supplies may prolong the duration of parturition, increase the number of stillbirths and result in a higher occurrence of skeletal problems. Tissue mineral reserves can be increased in various tissues with higher dietary fortification, but subsequent mineral availability from various pools differ. Because feed intake during lactation is low, daily mineral intake during lactation often is below NRC (1988) requirements.

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)

Evaluating two sources of dried whey and the effects of replacing the corn and dried whey component with corn gluten meal and lactose in the diets of weanling swine.

Three experiments were conducted to evaluate the efficacy of replacing corn and dried whey with corn gluten meal (CGM) and lactose, and to evaluate two sources of edible-grade dried whey that elicited different postweaning pig growth performances. In Exp. 1, two corn-soybean meal (C-SBM) diets without or with 20% dried whey (C-SBM-DW) were formulated to contain 1.15% lysine. A third diet replaced the corn and dried whey component with CGM and lactose. The experiment used 108 crossbred pigs weaned at 23 +/- 2 d of age weighing 6.25 kg BW and was conducted in six replicates as a randomized complete block design. Pig weight gains when the C-SBM-DW diet was fed were poor in one trial, whereas a second trial resulted in improved (P < .01) performance responses to the inclusion of dried whey. The CGM-SBM-lactose diet resulted in pig gains that equaled the performance responses of the C-SBM-DW diet of Trial 2. A second experiment was subsequently designed to evaluate the effects of adding lactose or lactalbumin to the CGM-SBM-DW diets using the two dried whey sources that had been identified as good or poor quality in Exp. 1. Diets included dried whey at a 25% level and were formulated to a low lysine level (.95%) to assess the nutritional efficacy of the dried whey sources.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of pasture, confinement, and diet fortification with vitamin E and selenium on reproducing gilts and their progeny.

A total of 48 gilts were used to evaluate the effects of a corn-soybean meal diet with or without vitamin E and Se fed on pasture or in confinement. The effects of these treatments on gilt serum and tissue alpha-tocopherol and Se concentrations and those of their progeny at weaning (28 d) were evaluated. During gestation, the experiment was a 2 x 2 factorial arrangement of treatments in a split-plot design that compared the housing system (pasture or confinement) and the effect of diets fortified with or without vitamin E (22 IU/kg) and Se (.3 ppm). The lactation study was a 2 x 2 factorial arrangement of treatments in a split-plot design evaluating the two housing systems during gestation or lactation only when gilts were fed the unfortified basal diet. The gilts fed the vitamin E- and Se-supplemented diet remained either on pasture or in confinement during both reproductive phases and served as positive controls. Gilts were bled at breeding, at 30, 60, and 90 d postcoitum, at farrowing, and at weaning (28 d). Three pigs per litter were bled from all litters at weaning. Six pigs per treatment group were killed at weaning and livers were collected. Pasture lots contained orchardgrass, ryegrass, and alfalfa; different lots were used during each reproductive phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of feed grains with dried skim milk and added carbohydrate sources on weanling pig performance.

Two experiments were conducted to evaluate the effects of 1) two grain mixtures and 2) various carbohydrate sources and levels fed to weanling pigs during the initial 2 wk postweaning. A total of 720 crossbred pigs were weaned at 23 +/- 2 d of age at an average BW of 5.8 kg. In Exp. 1, a 2 x 3 factorial experiment in a randomized complete block design was conducted in 12 replicates. Treatment diets formulated to 1.40% lysine were fed for a 14-d period. These diets contained dried skim milk (DSM) at a 45% level and an oat groat-soybean meal (OG-SBM-DSM) or a corn-soybean meal (C-SBM-DSM) mixture. In addition, the diets contained one of three carbohydrate sources (cornstarch, dextrose, lactose) at a 12% level. From 15 to 35 d postweaning, all groups were fed a 1.15% lysine corn-soybean meal (C-SBM) diet. The results demonstrated that during the period from 0 to 14 d weight gains were similar when either grain source was provided, but gain:feed ratio was superior and serum urea N was lower when the OG-SBM-DSM diet was fed. The addition of lactose or dextrose to either grain mixture resulted in greater weight gains (P <.05) than when cornstarch was the carbohydrate source. The second experiment was a randomized complete block design conducted in six replicates. The C-SBM-DSM diet of Exp. 1 served as the positive control diet. The other diets used corn gluten meal (CGM), SBM, and DSM with the three carbohydrate sources added at 22.5 or 35.5%.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of pig weaning weight and associated nursery feeding programs on subsequent performance to 105 kilograms body weight.

An experiment using a total of 210 crossbred pigs from two farrowing groups evaluated the effects of three weaning weights and their associative starter feeding program on subsequent postweaning performance to 105 kg BW. One group of pigs nursed their dams in outside heated hutches (Trial 1), and a second group was raised in a centrally heated farrowing house (Trial II). The three pig weaning weight groups ranged in weight from 1) 4.1 to 5.0 kg, 2) 5.5 to 6.8 kg, and 3) 7.3 to 8.6 kg. Pigs in Group 1 were fed a high nutrient dense diet (HNDD) for a 2-wk period followed by a corn-soybean meal-dried whey (C-SBM-DW) and then a corn-soybean meal (C-SBM) diet, each for a 2-wk period. Group 2 was fed the same diet sequence except that HNDD was provided for 1 wk, whereas Group 3 was provided only the C-SBM-DW and the C-SBM diets each for 2 wk, consecutively. At the end of the nursery period, pigs were fed C-SBM diet formulations to 105 kg BW. Pigs of Trial I averaged 5.2 d older at weaning than those raised in the central farrowing house, but only a 1.5-d difference existed between light- and heavy-weight groups in both trials. Gains and feed intakes for the three weaning groups were higher as weaning weight increased during both the nursery and the growing-finishing period. There did not seem to be a compensatory growth response for lighter-weight weanling pigs even though they had been fed starter diets containing milk products. Consequently, fewer days (approximately 15) were required for the heavier-weight weanling pig group to reach a final weight of 105 kg than for the light-weight group. The medium-weight group required an intermediate number of days to reach 105 kg.