Sow performance in response to natural betaine fed during lactation and post-weaning during summer and non-summer months.

BACKGROUND: Two studies were conducted to evaluate the effects of dietary natural betaine on sow reproductive performance during summer (Exp. 1) and non-summer months (Exp. 2). Treatments were designed as a 2 × 2 factorial arrangement with factors including dietary betaine (0 or 0.2%) and period of supplementation (lactation or post-weaning until 35 days post-insemination). In Exp. 1, 322 and 327 sows and in Exp. 2, 300 and 327 sows representing young (parity 1 and 2) and mature (parity 3 to 6) sows, respectively, were used. RESULTS: In Exp. 1, supplementation of betaine during lactation increased sow body weight losses (- 11.95 vs. -14.63 kg; P = 0.024), reduced feed intake (4.12 vs. 4.28 kg/d; P = 0.052), and tended to reduce percentage of no-value pigs (P = 0.071). Betaine fed post-weaning reduced weaning-to-estrus interval (5.75 vs. 6.68 days; P = 0.054) and farrowing rate (86.74% vs. 91.36%; P = 0.060), regardless of parity group. Post-hoc analysis with sows clustered into 3 parity groups (1, 2 and 3, and 4+) indicated that betaine fed in lactation to parity 4+ sows (P = 0.026) and betaine fed post-weaning to parity 1 sows increased the number of pigs born in the subsequent cycle (P ≤ 0.05). In Exp. 2, betaine fed during lactation tended to reduce the weaning-to-estrus interval (6.64 vs. 7.50 days; P = 0.077) and farrowing rate (88.23% vs. 83.54%; P = 0.089), regardless of parity group. Feeding betaine post-weaning reduced number of pigs born (13.00 vs. 13.64; P = 0.04) and pigs born alive (12.30 vs. 12.82; P = 0.075), regardless of parity group. CONCLUSIONS: Using 0.2% betaine during the non-summer months did not benefit sow performance. During the summer, betaine supplementation in lactation increased subsequent litter size in parity 4+ sows. Betaine fed during the post-weaning period reduced the wean-to-estrus interval and farrowing rate, increased total number of pigs born for parity 1 sows and reduced total number of pigs born to parity 4+ sows. Further research is needed to determine if the detrimental effects on feed intake and farrowing rate may be correlated and depend on dietary betaine level.

Growth performance, oxidative stress and immune status of newly weaned pigs fed peroxidized lipids with or without supplemental vitamin E or polyphenols.

BACKGROUND: This study evaluated the use of dietary vitamin E and polyphenols on growth, immune and oxidative status of weaned pigs fed peroxidized lipids. A total of 192 piglets (21 days of age and body weight of 6.62 ± 1.04 kg) were assigned within sex and weight blocks to a 2 × 3 factorial arrangement using 48 pens with 4 pigs per pen. Dietary treatments consisted of lipid peroxidation (6% edible soybean oil or 6% peroxidized soybean oil), and antioxidant supplementation (control diet containing 33 IU/kg DL-α-tocopheryl-acetate; control with 200 IU/kg additional dl-α-tocopheryl-acetate; or control with 400 mg/kg polyphenols). Pigs were fed in 2 phases for 14 and 21 days, respectively. RESULTS: Peroxidation of oil for 12 days at 80 °C with exposure to 50 L/min of air substantially increased peroxide values, anisidine value, hexanal, and 2,4-decadienal concentrations. Feeding peroxidized lipids decreased (P < 0.001) body weight (23.16 vs. 18.74 kg), daily gain (473 vs. 346 g/d), daily feed intake (658 vs. 535 g/d) and gain:feed ratio (719 vs. 647 g/kg). Lipid peroxidation decreased serum vitamin E (P < 0.001) and this decrease was larger on day 35 (1.82 vs. 0.81 mg/kg) than day 14 (1.95 vs. 1.38 mg/kg). Supplemental vitamin E, but not polyphenols, increased (P ≤ 0.002) serum vitamin E by 84% and 22% for control and peroxidized diets, respectively (interaction, P = 0.001). Serum malondialdehyde decreased (P < 0.001) with peroxidation on day 14, but not day 35 and protein carbonyl increased (P < 0.001) with peroxidation on day 35, but not day 14. Serum 8-hydroxydeoxyguanosine was not affected (P > 0.05). Total antioxidant capacity decreased with peroxidation (P < 0.001) and increased with vitamin E (P = 0.065) and polyphenols (P = 0.046) for the control oil diet only. Serum cytokine concentrations increased with feeding peroxidized lipids on day 35, but were not affected by antioxidant supplementation (P > 0.05). CONCLUSION: Feeding peroxidized lipids negatively impacted growth performance and antioxidant capacity of nursery pigs. Supplementation of vitamin E and polyphenols improved total antioxidant capacity, especially in pigs fed control diets, but did not restore growth performance.

Effect of natural betaine and ractopamine HCl on whole-body and carcass growth in pigs housed under high ambient temperatures.

Betaine is an osmolyte that helps to maintain water homeostasis and cell integrity, which is essential during heat stress. We hypothesized that supplemental betaine can improve growth during heat stress and may further improve the response to ractopamine. Two studies were conducted to determine: 1) the effects of betaine in combination with ractopamine; and 2) the optimum betaine level for late finishing pigs during heat stress. Heat stress was imposed by gradually increasing temperatures over 10 d to the target high temperature of 32°C. In Exp. 1, pigs ( = 1477, BW = 91.6 ± 3 kg) were assigned within BW blocks and sex to 1 of 4 diets arranged in a 2 × 2 factorial RCB design (68 pens; 20 to 23 pigs/pen). Treatments consisted of diets without or with ractopamine (5 mg/kg for 21 d followed by 8.8 mg/kg to market) and each were supplemented with either 0 or 0.2% of betaine. Betaine reduced ( ≤ 0.05) BW (123.1 vs. 124.3 kg), ADG (0.780 vs. 0.833 kg/d), and ADFI (2.800 vs. 2.918 kg/d), but did not impact carcass characteristics. Ractopamine increased ( < 0.01) BW (125.5 vs. 121.9 kg), ADG (0.833 vs. 0.769 kg/d), G:F (0.295 vs. 0.265), HCW (94.1 vs. 90.0 kg), carcass yield (74.8 vs. 73.8%), loin depth (63.6 vs. 60.0 mm), and predicted lean percentage (53.2 vs. 51.7%) and reduced ADFI (2.822 vs. 2.896 kg/d, = 0.033) and backfat depth ( < 0.001; 20.2 vs. 22.5 mm). In Exp. 2, pigs ( = 2193, BW = 95.5 ± 3.5 kg) were allocated within BW blocks and sex to 1 of 5 treatments in a RCB design (100 pens; 20 to 24 pigs/pen). Treatments consisted of diets with 0, 0.0625, 0.125, 0.1875% of betaine, and a positive control diet with ractopamine, but not betaine. Betaine tended to decrease carcass yield quadratically ( = 0.076; 74.1, 73.5, 73.8, and 73.9 for 0, 0.0625, 0.125, 0.1875% of betaine, respectively), but did not impact other responses. Ractopamine improved ( < 0.001) BW (121.6 vs. 118.5 kg), G:F (0.334 vs. 0.295), carcass yield (74.7 vs. 73.8%), loin depth (61.7 vs. 59.0 mm), and predicted lean percentage (53.2 vs. 52.6%), and reduced backfat (18.7 vs. 20.4 mm). Collectively, data indicate that under commercial conditions, betaine did not improve performance of pigs housed under high ambient temperatures, regardless of ractopamine inclusion. Ractopamine improved whole-body growth and especially carcass growth of pigs raised under high ambient temperatures. The ability of ractopamine to stimulate growth during heat stress makes it an important production technology.

Effects of dietary supplementation of the osmolyte betaine on growing pig performance and serological and hematological indices during thermoneutral and heat-stressed conditions.

The present study was designed to evaluate the effects of dietary betaine on pig performance and serological and hematological indices during thermoneutral and heat-stressed conditions. Individually housed pigs ( = 64; 39.0 ± 1.5 kg BW) were assigned within weight blocks and sex to 1 of 8 treatments. Treatments consisted of 2 environmental conditions (thermoneutral or heat-stressed) and 4 levels of betaine (0, 0.10, 0.15, and 0.20%). Room temperatures followed a daily pattern with a low of 14°C and a high of 21°C for the thermoneutral environment and a low of 28°C and a high of 35°C for the heat-stressed environment. Experimental diets were fed from d -7 (7 d prior to imposing temperature treatments; constant 21°C) until 28. Respiration rate and rectal temperature were measured on d 0, 1, 2, 3, 7, 14, 21, and 28, and blood samples were collected on d 3 and 28. Heat stress reduced ( ≤ 0.008) ADG (0.710 vs. 0.822 kg/d) and ADFI (1.81 vs. 2.27 kg/d) and increased G:F ( = 0.036; 0.391 vs. 0.365). Betaine tended to quadratically increase G:F ( = 0.071; 0.377, 0.391, 0.379, and 0.366 for 0, 0.10, 0.15, and 0.20% betaine, respectively), regardless of environment. Heat stress increased ( ≤ 0.001) respiration rate (48 vs. 23 breaths/30 s) and rectal temperature (39.47 vs. 38.94°C) throughout d 1 to 28. Betaine at 0.10% reduced rectal temperature in heat-stressed pigs but not in control pigs (interaction, = 0.040). Heat stress increased serum cysteine and triglycerides and reduced Ca, alkaline phosphatase, and lipase, regardless of day of sampling ( ≤ 0.048). Heat stress increased serum creatine phosphokinase (CPK) and K and reduced osmolarity, Na, urea N, methionine, homocysteine, the albumin:globulin ratio, and blood eosinophil count on d 3 but not on d 28 (interaction, ≤ 0.013). Heat stress increased serum Mg, globulin, creatinine, amylase, and γ-glutamyltranspeptidase and reduced , the urea N:creatinine ratio, alanine aminotransferase, NEFA, hemoglobin, hematocrit, and red blood cells on d 28 but not on d 3 (interaction, ≤ 0.034). Betaine increased serum osmolarity and NEFA and reduced CPK and K on d 3 but not on d 28 (interaction, ≤ 0.060) and increased serum creatinine and reduced amylase on d 28 but not on d 3 (interaction ≤ 0.057). Heat stress reduced growth, disturbed ion balance, and increased markers of muscle damage. Betaine had a minor impact on alleviating heat stress with the possible exception of early days of heat exposure. The beneficial effect of betaine was diminished by pig adaptation.

Effects of high inclusion of soybean meal and a phytase superdose on growth performance of weaned pigs housed under the rigors of commercial conditions.

Two studies were conducted to determine whether soybean meal (SBM) use in nursery pig diets can be increased by superdosing with phytase. In Exp. 1, 2,550 pigs (BW of 5.54 ± 0.09 kg) were used to evaluate the optimal level of phytase in low- or high-SBM diets. Two SBM levels (low and high) and 4 phytase doses (0, 1,250, 2,500, and 3,750 phytase units [FTU]/kg) were combined to create 8 dietary treatments in a 2 × 4 factorial arrangement. Pigs were fed a 3-phase feeding program, with each period being 10, 10, and 22 d, respectively. Inclusion of low and high SBM was 15.0 and 25.0%, respectively, for Phase 1; 19.0 and 29.0%, respectively, for Phase 2; and 32.5% for the common Phase 3 diet. Pigs fed diets with high SBM had improved G:F for Phase 1 and 2 and overall ( < 0.01) compared with low-SBM diets. Phytase quadratically improved G:F during Phase 3 and overall ( < 0.05), with the optimum phytase dose being 2,500 FTU/kg. High-SBM diets tended ( = 0.09) to decrease stool firmness (determined daily from d 1 to 10) only on d 2. In Exp. 2, 2,112 pigs (BW of 5.99 ± 0.10 kg) were used to evaluate the impact of high levels of SBM and phytase on performance, stool firmness, mortality, and morbidity in weaned pigs originating from a porcine reproductive and respiratory syndrome (PRRS) virus-positive sow farm. Pigs were fed a 3-phase feeding program as in Exp. 1. Three levels of SBM (low, medium, or high) and 2 phytase levels (600 or 2,600 FTU) were combined to create 6 dietary treatments in a 3 × 2 factorial arrangement. Inclusion of SBM was 15.0, 22.5, and 30.0% for Phase 1 and 20.0, 27.5, and 35.0% for Phase 2 for low, medium, and high SBM, respectively, and 29.0% for the common Phase 3 diet. Inclusion of SBM did not affect growth performance. The percentage of pigs removed for medical treatment linearly declined with increasing SBM levels ( = 0.04). High-SBM diets tended ( < 0.10) to decrease stool firmness during d 4 and 5 and high phytase tended ( < 0.10) to improve stool firmness on d 2 and 4. Analyzed PRRS titers in saliva samples collected on d 20 and 42 confirmed the PRRS status of the pigs; however, viral load was not impacted by dietary treatments ( ≥ 0.11). Results indicate that SBM levels in early nursery diets can be increased without decreasing growth performance and may be favorable in pigs originating from PRRS-positive sow farms by reducing costs of medical treatments. Supplementation of phytase at superdose levels can improve growth performance independently from the level of SBM in the diet.

Enzyme supplementation to improve the nutritional value of fibrous feed ingredients in swine diets fed in dry or liquid form.

This study evaluated the effect of xylanase supplementation (with or without), feeding method (dry or liquid), and feedstuff (corn distiller's dried grains with solubles [DDGS] or wheat middlings) on apparent total tract digestibility (ATTD) and apparent ileal digestibility (AID) of GE and nutrients, intestinal morphology, ileal and cecal pH, and VFA concentrations. Sixty-four growing pigs (25.87 ± 0.38kg initial BW) were blocked by BW and sex and randomly assigned to 8 dietary treatments. Within each feedstuff, diets were fed either liquid or dry, without or with xylanase (24,000 birch xylan units/kg feed), for 16 d. Diets contained 3.32 and 3.19 Mcal/kg ME for DDGS- and wheat middlings-based diets, respectively. Pigs were fed restricted at 3 times maintenance ME requirements. Liquid diets were prepared by steeping DDGS or wheat middlings with water (1:3, wt/vol) with or without xylanase for 24 h followed by mixing with a basal ingredient mixture and water to achieve a final ratio of 1:2.5 (wt/vol). During steeping of wheat middlings, some fiber degradation occurred. When xylanase was added in dry wheat middlings diets, AID of GE ( < 0.10) and NDF ( < 0.05) increased compared with dry wheat middlings diets without xylanase (64.50 vs. 54.67% and 52.88 vs. 31.69%, respectively), but supplementation of xylanase did not impact AID of GE and NDF when liquid wheat middlings diets were fed. Xylanase in liquid DDGS diets increased ( < 0.05) the AID of NDF compared with liquid DDGS diets without xylanase, but xylanase did not affect AID of NDF in dry DDGS diets. Xylanase in wheat middlings diets improved ( < 0.05) ATTD of GE and N compared with wheat middlings diets without xylanase (80.37 vs. 78.07% and 80.23 vs. 77.94%, respectively). However, there was no effect of xylanase in DDGS diets. Pigs fed DDGS diets had greater concentrations of butyrate in the cecum ( = 0.001) than pigs fed wheat middlings diets (27.6 vs. 20.4 mmol/L). Pigs fed DDGS diets with xylanase had deeper crypts ( < 0.05) in the jejunum than pigs fed DDGS diets without xylanase (98.20 vs. 86.16 µm), but xylanase had no effect in pigs fed wheat middlings diets. Results suggest that liquid feeding and xylanase supplementation had limited potential to enhance nutrient digestibility in pigs fed DDGS-based diets. However, xylanase supplementation in dry wheat middlings-based diets improved the AID of NDF and ATTD of GE and N, but liquid feeding as pretreatment did not further enhance the nutritional value of wheat middlings-based diets.

A cooperative study on the standardized total-tract digestible phosphorus requirement of twenty-kilogram pigs.

A cooperative study comprising growth performance, bone mineralization, and nutrient balance experiments was conducted at 11 stations to determine the standardized total-tract digestible (STTD) P requirement of 20-kg pigs using broken-line regression analysis. Monocalcium phosphate and limestone were added to a corn-soybean meal-based diet at the expense of cornstarch to establish 6 concentrations of STTD P from 1.54 to 5.15 g/kg in increments of 0.62 g/kg at a constant Ca:total P of 1.52:1.0. Diets were fed to 936 pigs (average initial BW of 19 kg) in 240 pens for 20 replicate pens of barrows and 20 replicate pens of gilts per diet. As STTD P increased from 1.54 to 5.15 g/kg of the diet for d 0 to 14, 14 to 28, and 0 to 28, the ADG, ADFI, and G:F increased ( < 0.01). Barrows gained and ate more ( < 0.05) than gilts during d 14 to 28 and 0 to 28. There was no interaction between sex and STTD P concentration for any of the growth performance response criteria. There were both linear and quadratic increases ( < 0.05) in mineral density and content of ash, Ca, and P in the femur expressed as a percentage of dry, fat-free metacarpal as dietary STTD P increased. Furthermore, the maximum load of the femur and mineral density and content and maximum load as well as the Ca and P expressed as a percentage of metacarpal ash linearly increased ( < 0.01) with increasing dietary concentrations of STTD P. There were both linear and quadratic increases ( < 0.01) in apparent digestibility and retention of P with increasing concentrations of STTD P in the diets. Digestibility and retention of Ca linearly ( < 0.01) increased with increasing dietary concentrations of STTD P. Breakpoints determined from nonlinear broken-line regression analyses revealed estimates of 4.20 ± 0.102, 3.20 ± 0.036, or 3.87 ± 0.090 g/kg for ADG during d 0 to 14, 14 to 28, or 0 to 28, respectively. Corresponding estimates using G:F as the response criterion were 4.34 ± 0.146, 3.38 ± 0.139, or 4.08 ± 0.195 g/kg. When mineralization of the femur was used as criteria of response, estimates of STTD P requirement were 4.28, 4.28, or 4.34, g/kg for mineral density, mineral content, or maximum load, respectively. Using mineralization of the metacarpal as criteria of response, estimates of STTD P requirement ranged from 3.5 to 5.0 g/kg depending on the metacarpal response criteria. The study provided empirical estimates of STTD P requirements of 20- to 40-kg pigs.

Impact of dietary lipids on sow milk composition and balance of essential fatty acids during lactation in prolific sows.

Two studies were designed to determine the effects of supplementing diets with lipid sources of EFA (linoleic and α-linolenic acid) on sow milk composition to estimate the balance of EFA for sows nursing large litters. In Exp. 1, 30 sows, equally balanced by parity (1 and 3 to 5) and nursing 12 pigs, were fed diets supplemented with 6% animal-vegetable blend (A-V), 6% choice white grease (CWG), or a control diet without added lipid. Diets were corn-soybean meal based with 8% corn distiller dried grains with solubles and 6% wheat middlings and contained 3.25 g standardized ileal digestible Lys/Mcal ME. Sows fed lipid-supplemented diets secreted greater amounts of fat (P = 0.082; 499 and 559 g/d for control and lipid-added diets, respectively) than sows fed the control diet. The balance of EFA was computed as apparent ileal digestible intake of EFA minus the outflow of EFA in milk. For sows fed the control diet, the amount of linoleic acid secreted in milk was greater than the amount consumed, throughout lactation. This resulted in a pronounced negative balance of linoleic acid (-22.4, -38.0, and -14.1 g/d for d 3, 10, and 17 of lactation, respectively). In Exp. 2, 50 sows, equally balanced by parity and nursing 12 pigs, were randomly assigned to a 2 × 2 factorial arrangement of diets plus a control diet without added lipids. Factors included linoleic acid (2.1% and 3.3%) and α-linolenic acid (0.15% and 0.45%). The different concentrations of EFA were obtained by adding 4% of different mixtures of canola, corn, and flaxseed oils to diets. The n-6 to n-3 fatty acid ratios in the diets ranged from 5 to 22. Increasing supplemental EFA increased (P < 0.001) milk concentrations of linoleic (16.7% and 20.8%, for 2.1% and 3.3% linoleic acid, respectively) and α-linolenic acid (P < 0.001; 1.1 and 1.9% for 0.15 and 0.45% α-linolenic acid, respectively). Increasing supplemental EFA increased the estimated balance of α-linolenic acid (P < 0.001; -0.2 and 5.3 g/d for 0.15% and 0.45% α-linolenic acid, respectively), but not linoleic acid (P = 0.14; -3.4 and 10.0 g/d for 2.1% and 3.3% linoleic acid, respectively). In conclusion, lipid supplementation to sow lactation diets improved milk fat secretion. The fatty acid composition of milk fat reflected the dietary supplementation of EFA. The net effect of supplemental EFA was to create a positive balance during lactation, which may prove to be beneficial for the development of nursing piglets and the subsequent reproduction of sows.

Development of prediction equations to estimate the apparent digestible energy content of lipids when fed to lactating sows.

Two studies were conducted 1) to determine the effects of free fatty acid (FFA) concentrations and the degree of saturation of lipids (unsaturated to saturated fatty acids ratio [U:S]) on apparent total tract digestibility (ATTD) and DE content of lipids and 2) to derive prediction equations to estimate the DE content of lipids when added to lactating sow diets. In Exp. 1, 85 lactating sows were assigned randomly to a 4 × 5 factorial arrangement of treatments plus a control diet with no added lipid. Factors included 1) FFA concentrations of 0, 18, 36, and 54% and 2) U:S of 2.0, 2.8, 3.5, 4.2, and 4.9. Diets were corn-soybean meal based and lipid was supplemented at 6%. Concentrations of FFA and U:S were obtained by blending 4 lipid sources: choice white grease (CWG; FFA = 0.3% and U:S = 2.0), soybean oil (FFA = 0.1% and U:S = 5.5), CWG acid oil (FFA = 57.8% and U:S = 2.1), and soybean-cottonseed acid oil (FFA = 67.5% and U:S = 3.8). Titanium dioxide was added to diets (0.5%) as a digestibility marker. Treatments started on d 4 of lactation and fecal samples were collected after 6 d of adaptation to diets on a daily basis from d 10 to 13. The ATTD of added lipid and DE content of lipids were negatively affected (linear, < 0.001) with increasing FFA concentrations, but negative effects were less pronounced with increasing U:S (interaction, < 0.05). Coefficients of ATTD for the added lipid and DE content of lipids increased with increasing U:S (quadratic, = 0.001), but these improvements were less pronounced when the FFA concentration was less than 36%. Digestible energy content of added lipid was described by DE (kcal/kg) = [8,381 - (80.6 × FFA) + (0.4 × FFA) + (248.8 × U:S) - (28.1 × U:S) + (12.8 × FFA × U:S)] ( = 0.74). This prediction equation was validated in Exp. 2, in which 24 lactating sows were fed diets supplemented with 6% of either an animal-vegetable blend (A-V; FFA = 14.5% and U:S = 2.3) or CWG (FFA = 3.7% and U:S = 1.5) plus a control diet with no added lipids. Digestible energy content of A-V (8,317 and 8,127 kcal/kg for measured and predicted values, respectively) and CWG (8,452 and 8,468 kcal/kg for measured and predicted values, respectively) were accurately estimated using the proposed equation. The proposed equation involving FFA concentration and U:S resulted in highly accurate estimations of DE content (relative error, +0.2 to -2.3%) of commercial sources of lipids for lactating sows.

Supplementation of organic and inorganic selenium to diets using grains grown in various regions of the United States with differing natural Se concentrations and fed to grower-finisher swine.

Grains grown in various regions of the United States vary in their innate or natural Se contents. A regional study evaluated the effects of adding inorganic Se (sodium selenite) or organic Se (Se yeast) to diets with differing innate Se contents. A 2 × 2 + 1 factorial experiment evaluating 2 Se sources (organic or inorganic) at 2 Se levels (0.15 or 0.30 mg/kg) in 18 total replicates (n = 360 total pigs). A basal diet was fed without supplemental Se and served as the negative (basal) control. The study was conducted as a randomized complete block design in 9 states (Georgia, Illinois, Kentucky, Nebraska, North Carolina, Ohio, South Dakota, Texas, and Wisconsin) with each station conducting 2 replicates. Pigs were fed from 25 to approximately 115 kg BW. Similar dietary formulations were used at each station, incorporating a common source of trace mineral and Se premixes. Three pigs per treatment in 16 replicates (n = 240) were bled at 55, 85, and 115 kg BW and serum Se and glutathione peroxidase (GSH-Px) activities were determined. Three pigs (n = 260) from each treatment pen were killed at 115 kg BW and issues (liver, loin, and hair) were analyzed for Se. The corn Se content from the various states ranged from 0.026 to 0.283 mg Se/kg while the soybean meal Se content ranged from 0.086 to 0.798 mg Se/kg. Tissue and serum Se concentrations were greater (P < 0.01) when supplemental organic Se was fed, whereas serum GSH-Px was greater (P < 0.01) as Se level increased. There were linear increases (P < 0.01) in loin and quadratic increases (P < 0.01) in liver and hair Se concentrations as dietary Se level increased within each state. There was a source × level interaction (P < 0.01) for each tissue resulting in a greater increase when organic Se was fed. Serum Se and GSH-Px activity increased (P < 0.01) when both Se sources were fed and plateaued at each state at 0.15 mg Se/kg. There was a high and significant correlation between each tissue Se, serum Se, and GSH-Px activity to dietary Se level indicating that those states having greater grain natural Se contents also had greater tissue Se concentrations. These results indicate that a large difference in corn and soybean meal Se concentrations exists between states, that the addition of organic or inorganic Se to these grains increased tissue and serum Se in each state, and that organic Se was incorporated at greater concentrations in the loin, liver, and hair tissues of grower-finisher pigs than inorganic Se.

Effects of dietary lipid sources on performance and apparent total tract digestibility of lipids and energy when fed to nursery pigs.

Acidulated fats and oils are by-products of the fat-refining industry. They contain high levels of FFA and are 10% to 20% less expensive than refined fats and oils. Two studies were designed to measure the effects of dietary lipid sources low or high in FFA on growth performance and apparent total tract digestibility (ATTD) of lipids and GE in nursery pigs. In Exp. 1, 189 pigs at 14 d postweaning (BW of 9.32 ± 0.11 kg) were used for 21 d with 9 replicate pens per treatment and 3 pigs per pen. Dietary treatments consisted of a control diet without added lipids and 6 diets with 6% inclusion of lipids. Four lipid sources were combined to create the dietary treatments with 2 levels of FFA (0.40% or 54.0%) and 3 degrees of fat saturation (iodine value [IV] = 77, 100, or 123) in a 2 × 3 factorial arrangement. Lipid sources were soybean oil (0.3% FFA and IV = 129.4), soybean-cottonseed acid oil blend (70.5% FFA and IV = 112.9), choice white grease (0.6% FFA and IV = 74.8), and choice white acid grease (56.0% FFA and IV = 79.0). Addition of lipid sources decreased ADFI (810 vs. 872 g/d; P = 0.018) and improved G:F (716 vs. 646 g/kg; P < 0.001). Diets high in FFA tended (P = 0.08) to improve final BW (21.35 vs. 21.01 kg) and ADG (576 vs. 560 g/d). Lipid-supplemented diets had greater ATTD of lipids than control diets (67.4% vs. 29.7%; P < 0.001). Apparent total tract digestibility of lipids was greater in diets with low FFA (69.9% vs. 64.9%; P < 0.001) and decreased linearly with increasing IV (73.2%, 69.1%, and 67.2%). For GE, ATTD was greater in diets with low FFA (83.1% vs. 80.9%; P = 0.001). In Exp. 2, 252 pigs at 7 d postweaning (BW of 7.0 ± 0.2 kg) were used for 28 d with 9 replicate pens per treatment and 4 pigs per pen. Diets included a control diet without added lipids and 6 treatments with 2.5%, 5.0%, or 7.5% of lipids from either poultry fat (1.9% FFA) or acidulated poultry fat (37.8% FFA) in a 2 × 3 factorial arrangement. Addition of lipids increased (P < 0.001) final BW (19.9 vs. 18.4 kg) and ADG (460 vs. 405 g/d) regardless of source. Fat increased (P < 0.001) ADFI when added at 2.5% and then decreased ADFI with each further increment (663, 740, 681, and 653 g for 0%, 2.5%, 5.0%, and 7.5% fat, respectively). Inclusion of lipids linearly (P < 0.001) improved G:F (615, 615, 688, and 692 g/kg for 0%, 2.5%, 5.0%, and 7.5% fat, respectively) and ATTD of lipids (17.8%, 50.2%, 71.0%, and 77.3% for 0, 2.5, 5.0, and 7.5% fat, respectively) and GE (76.1%, 76.4%, 83.3%, and 84.4% for 0%, 2.5%, 5.0%, and 7.5% fat, respectively). Acidulated lipids resulted in similar performance compared with refined lipids and could be economical alternatives to more expensive lipid sources.

Stabilized rice bran improves weaning pig performance via a prebiotic mechanism.

Stabilized rice bran (SRB) is classified as a "functional food" because of its prebiotic characteristics. With increasing grain prices and the pressure to remove antibiotics from swine diets because of concern over antibiotic resistance, SRB was investigated as a nursery diet ingredient with and without the addition of antibiotics (ANT). Two hundred pigs were weaned at 21 d of age, blocked by BW, and allotted to diets containing 0 or 10% SRB ± ANT according to a 2 × 2 factorial arrangement of treatments. Five animals were housed per pen throughout a 28-d growth period. At the end of the trial, 1 pig from each pen was euthanized for measurement of intestinal morphology. Antibiotic supplementation improved ADG by 6.4% during Phase 2 (d 14 to 28; P = 0.02), but other production variables were unaffected by ANT. During Phase 2 and cumulatively (d 0 to 28), the supplementation of SRB improved G:F by 10% in ANT-free pigs but not in pigs fed ANT (ANT × SRB, P < 0.03). Ileal histology revealed an increase in crypt depth of pigs fed the diet containing ANT plus SRB and corresponding decreases in villi:crypt associated with both ANT and SRB supplementation (P < 0.05). Intraepithelial lymphocytes were increased by 15% in pigs fed SRB without ANT, but were unaffected by SRB in pigs fed ANT (ANT x SRB, P = 0.003). Colonic bifidobacteria tended to increase with SRB supplementation (P < 0.10). Differences in ileal and cecal digesta short-chain fatty acid concentrations were not detected. In summary, SRB improved the efficiency of nutrient utilization in nursery diets lacking antibiotics and tended to increase intestinal bifidobacteria concentrations, indicating that SRB may exert beneficial prebiotic effects in weanling pigs.

Impact of two types of complete pelleted, wild ungulate feeds and two pelleted feed to hay ratios on the development of urolithogenic compounds in meat goats as a model for giraffes.

Urolith formation has been documented in giraffes and goats. As research in giraffes poses logistical challenges, 16 buck goats were used as a model. The impact of two commercially available, pelleted feeds used for giraffes, ADF-16 and Wild Herbivore (WH), as well as the impact of alfalfa hay and pellet proportions (20% hay:80% pellets, 80P or 80% hay:20% pellet, 20P) on the formation of urolithogenic precursors in goat urine was accomplished in a 2 × 2 factorial balance study. Complete diets contained 0.60, 0.32, 0.35 and 0.26% phosphorus (P) with calcium:P ratios of 1.60, 4.16, 3.06 and 5.23, for 80P-ADF-16, 20P-ADF-16, 80P-WH and 20P-WH respectively. Total faeces and urine were collected over two 5-day periods to assess N and mineral balance. Fresh urine samples were collected and evaluated microscopically for urolithic crystal content. Urinary nitrogen (N) was lower and N retention was higher in goats fed 80P diets (p < 0.05). Intake of P was greatest for goats fed 80P-ADF-16; however, urinary P excretion and P retention were not affected by treatment. Crystal scores were higher in animals receiving 80P diets (p = 0.08), with crystals being composed predominantly of calcium phosphate. Urine pH was alkaline (>8) for all treatments. Urinary P concentration, a risk factor for urolithiasis, was highest (p ≤ 0.06) in the 80P-ADF-16 treatment (0.38 vs. 0.01, 0.02 and 0.04 mg/dl for 20P-ADF-16, 80P-WH and 20P-WH respectively), reflecting its highest dietary P level. Further investigation is recommended to determine the long-term effects of these diets on urolithogenic compound formation.

Diet physical form, fatty acid chain length, and emulsification alter fat utilization and growth of newly weaned pigs.

An experiment was conducted to examine the interplay of diet physical form (liquid vs. dry), fatty acid chain length [medium- (MCT) vs. long-chain triglyceride (LCT)], and emulsification as determinants of fat utilization and growth of newly weaned pigs. Ninety-six pigs were weaned at 20.0 ± 0.3 d of age (6.80 ± 0.04 kg) and fed ad libitum 1 of 8 diets for 14 d according to a 2(3) factorial arrangement of treatments with 6 pens per diet and 2 pigs per pen. The MCT contained primarily C8:0 and C10:0 fatty acids, whereas the LCT mainly contained C16:0, C18:0, C18:1, and C18:2. Diet physical form greatly impacted piglet growth (P < 0.001), with liquid-fed pigs (486 g/d) growing faster than dry-fed pigs (332 g/d) by 46%. Pigs fed LCT grew 22% faster (P = 0.01) than MCT-fed pigs; however, effects of emulsifier were not detected (P > 0.1). Furthermore, feed intake and G:F were 15% and 29% greater for liquid-fed pigs, and intake also was 21% greater for pigs fed LCT (P = 0.01). Diet physical form had no effect on apparent ileal fatty acid digestibility, but as expected, digestibility was greater (P < 0.001) for the MCT than the LCT diet (98.5% vs. 93.4%). Emulsification improved digestibility of most fatty acids in pigs fed LCT but not MCT (interaction, P < 0.01). Both jejunal and ileal villi height increased from 7 to 14 d postweaning (P < 0.01). Liquid-fed pigs had greater jejunal crypt depth (P < 0.05) compared with pigs fed the dry diet; however, ileal morphology was not affected by diet physical form, fat chain length, or emulsification. Plasma ketone body concentrations were 6-fold greater in pigs fed MCT than LCT, and the difference was greater in pigs fed dry diets (interaction, P = 0.01). The bile salt concentration in jejunal digesta was 2.2-fold greater in pigs fed LCT than in pigs fed MCT (P < 0.001). Collectively, we conclude that feeding liquid diets containing emulsified LCT can improve fat utilization and markedly accentuate feed intake, growth, and G:F of weanling pigs.

Response of the modern lactating sow and progeny to source and level of supplemental dietary fat during high ambient temperatures.

The objective of this study was to determine the response to increments of 2 sources of dietary fat on lactating sow and progeny performance during high ambient temperatures. Data were collected from 391 sows (PIC Camborough) from June to September in a 2,600-sow commercial unit in Oklahoma. Sows were randomly assigned to a 2 × 3 factorial arrangement of treatments and a control diet. Factors included 1) fat sources, animal-vegetable blend (A-V) and choice white grease (CWG), and 2) fat levels (2%, 4%, and 6%). The A-V blend contained 14.5% FFA with an iodine value of 89, peroxide value of 4.2 mEq/kg, and anisidine value of 23, whereas CWG contained 3.7% FFA with an iodine value of 62, peroxide value of 9.8 mEq/kg, and anisidine value of 5. Diets were corn-soybean meal based, with 8.0% distillers dried grains with solubles and 6.0% wheat middlings, and contained 3.56-g standardized ileal digestible Lys/Mcal ME. Sows were balanced by parity, with 192 and 199 sows representing parity 1 and parity 3 to 5, respectively. Feed refusal increased linearly (P < 0.001) with the addition of supplemental fat, but feed and energy intake increased linearly (P < 0.01) with increasing dietary fat. Sows fed CWG diets had reduced (linear, P < 0.05) BW loss during lactation. Litter growth rate was not affected by additional dietary fat. Addition of CWG to the diets improved G:F (sow and litter gain relative to feed intake) compared with the G:F of sows fed the control diet or the diets containing the A-V blend (0.50, 0.43, and 0.44, respectively; P < 0.05). Gain:ME (kg/Mcal ME) was greater (P < 0.05) for CWG (0.146) than A-V blend (0.129) but was not different from that of the control diet (0.131). Addition of A-V blend and CWG both improved (P < 0.05) conception and farrowing rates and subsequent litter size compared with the control diet. In conclusion, energy intake increased with the addition of fat. The A-V blend contained a greater amount of aldehydes (quantified by anisidine value) and was more susceptible to oxidation, resulting in reduced feed efficiency than CWG. Subsequent litter size and reproductive performance was improved by inclusion of both sources of fat in diets fed to lactating sows.

Sow and litter response to supplemental dietary fat in lactation diets during high ambient temperatures.

The objective of this experiment was to determine the impact of supplemental dietary fat on total lactation energy intake and sow and litter performance during high ambient temperatures (27 ± 3°C). Data were collected from 337 mixed-parity sows from July to September in a 2,600-sow commercial unit in Oklahoma. Diets were corn-soybean meal-based with 7.5% corn distillers dried grains with solubles and 6.0% wheat middlings and contained 3.24 g of standardized ileal digestible Lys/Mcal of ME. Animal-vegetable fat blend (A-V) was supplemented at 0, 2, 4, or 6%. Sows were balanced by parity, with 113, 109, and 115 sows representing parity 1, 2, and 3 to 7 (P3+), respectively. Feed disappearance (subset of 190 sows; 4.08, 4.18, 4.44, and 4.34 kg/d, for 0, 2, 4, and 6%, respectively; P < 0.05) and apparent caloric intake (12.83, 13.54, 14.78, and 14.89 Mcal of ME/d, respectively; P < 0.001) increased linearly with increasing dietary fat. Gain:feed (sow and litter BW gain relative to feed intake) was not affected (P = 0.56), but gain:Mcal ME declined linearly with the addition of A-V (0.16, 0.15, 0.15, and 0.14 for 0, 2, 4, and 6%, respectively; P < 0.01). Parity 1 sows (3.95 kg/d) had less (P < 0.05) feed disappearance than P2 (4.48 kg/d) and P3+ (4.34 kg/d) sows. Body weight change in P1 sows was greater (P < 0.01) than either P2 or P3+ sows (-0.32 vs. -0.07 and 0.12 kg/d), whereas backfat loss was less (P < 0.05) and loin depth gain was greater (P < 0.05) in P3+ sows compared with P1 and P2 sows. Dietary A-V improved litter ADG (P < 0.05; 1.95, 2.13, 2.07, and 2.31 kg/d for 0, 2, 4, and 6% fat, respectively) only in P3+ sows. Sows bred within 8 d after weaning (58.3, 72.0, 70.2, and 74.7% for 0, 2, 4, and 6%, respectively); conception rate (78.5, 89.5, 89.2, and 85.7%) and farrowing rate (71.4, 81.4, 85.5, and 78.6%) were improved (P < 0.01) by additional A-V, but weaning-to-breeding interval was not affected. Rectal and skin temperature and respiration rate of sows were greater (P < 0.002) when measured at wk 3 compared with wk 1 of lactation, but were not affected by A-V addition. Parity 3+ sows had lower (P < 0.05) rectal temperature than P1 and P2 sows, and respiration rate was reduced (P < 0.001) in P1 sows compared with P2 and P3+ sows. In conclusion, A-V improved feed disappearance and caloric intake, resulting in improved litter weight gain and subsequent reproductive performance of sows; however, feed and caloric efficiency were negatively affected.

Distribution of ten antibiotic resistance genes in E. coli isolates from swine manure, lagoon effluent and soil collected from a lagoon waste application field.

The prevalence of ten antibiotic resistance genes (ARGs) was evaluated in a total of 616 Escherichia coli isolates from swine manure, swine lagoon effluent, and from soils that received lagoon effluent on a commercial swine farm site in Sampson County, North Carolina (USA). Isolates with ARGs coding for streptomycin/spectinomycin (aadA/strA and strB), tetracycline (tetA and tetB), and sulfonamide (sul1) occurred most frequently (60.6-91.3%). The occurrence of E. coli isolates that carried aadA, tetA, tetB, and tetC genes was significantly more frequent in soil samples (34.0-97.2%) than in isolates from lagoon samples (20.9-90.6%). Furthermore, the frequency of isolates that contain genes coding for aadA and tetB was significantly greater in soil samples (82.6-97.2%) when compared to swine manure (16.8-86.1%). Isolates from the lagoon that carried tetA, tetC, and sul3 genes were significantly more prevalent during spring (63.3-96.7%) than during winter (13.1-67.8%). The prevalence of isolates from the lagoon that possessed the strA, strB, and sul1 resistance genes was significantly more frequent during the summer (90.0-100%) than during spring (66.6-80.0%). The data suggest that conditions in the lagoon, soil, and manure may have an impact on the occurrence of E. coli isolates with specific ARGs. Seasonal variables seem to impact the recovery isolates with ARGs; however, ARG distribution may be associated with mobile genetic elements or a reflection of the initial numbers of resistant isolates shed by the animals.

Evaluation of the nutritional value of glycerol for nursery pigs.

In Exp. 1, a total of 144 pigs (BW, 6.68 ± 0.17 kg) were weaned at 21 d, blocked by BW, and allocated to 48 pens with 3 pigs per pen. Pens were randomly assigned to 1 of 6 dietary treatments (0, 2.5, 5, 7.5, and 10% glycerol supplemented to replace up to 10% lactose in a basal starter 1 diet containing 20% total lactose, which was fed for 2 wk), and a negative control diet with 10% lactose and 0% glycerol. A common starter diet was fed for the next 2 wk. In Exp. 2, a total of 126 pigs (BW, 6.91 ± 0.18 kg) were weaned at 21 d of age, blocked by BW, and allocated to 42 pens with 3 pigs per pen. Pigs were assigned to 1 of 6 treatments in a 2 × 3 factorial arrangement in a randomized complete block design with factors being 1) glycerol inclusion in replacement of lactose in starter 1 diets (0 or 5%) fed for 2 wk, and 2) glycerol inclusion in starter 2 diets (0, 5, or 10%) fed for 3 wk. In Exp. 1, glycerol supplementation at 10% improved (P=0.01) ADG (266 vs. 191 g/d) and G:F (871 vs. 679 g/kg) during the starter 1 period when compared with the negative control. Incremental amounts of glycerol linearly (P<0.05) increased ADG and ADFI, but did not affect G:F during starter 1. There was no effect of feeding glycerol during the starter 1 phase on subsequent performance during the starter 2 phase or overall. Serum glycerol concentrations increased linearly (P=0.003) with increasing dietary glycerol, and serum creatinine (P=0.004) and bilirubin (P=0.03) concentrations decreased with increasing glycerol. In Exp. 2, glycerol did not affect performance during starter 1, but it linearly increased (P≤0.01) ADG and ADFI during starter 2 (464, 509, and 542 and 726, 822, and 832 g/d, respectively) and overall (368, 396, and 411 and 546, 601, and 609 g/d, respectively). At the end of the study, pigs were 1.0 and 1.5 kg heavier when fed 5 and 10% glycerol, respectively (linear, P<0.01). Serum glycerol concentrations increased linearly during starter 2 (P<0.001), but were not affected during starter 1. Glycerol supplementation increased serum urea N quadratically (P<0.001) and decreased creatinine linearly (P<0.05) in the starter 2 phase. Overall, data indicate that glycerol can be added to nursery pig diets at 10%, while improving growth performance.

Feed preferences and performance of nursery pigs fed diets containing various inclusion amounts and qualities of distillers coproducts and flavor.

We evaluated the preferences of nursery pigs for diets containing increasing distillers dried grains with solubles (DDGS), varying in color, or high-protein distillers dried grains (HP-DDG) and the effects of flavor supplementation on pig preference and growth performance. In Exp. 1 through 5, diet preference was determined in weanling pigs adjusted to a commercial diet for at least 10 d, and then housed individually for a 2-d double-choice preference test. In Exp. 1, a total of 60 pigs (11.6 ± 0.3 kg of BW) were given a choice between a reference diet (0% DDGS) and test diets containing 0, 10, 20, or 30% DDGS. In Exp. 2, a total of 80 pigs (10.8 ± 0.1 kg of BW) were given a choice between a reference diet (0% HP-DDG) and diets containing 0, 10, 20, or 30% HP-DDG. In Exp. 3, a total of 80 pigs (10.3 ± 0.2 kg of BW) were given a choice between a reference diet (0% DDGS) and a diet containing 0%, 30% light, or 30% dark DDGS. In Exp. 4, a total of 80 pigs (11.2 ± 0.2 kg of BW) were given a choice between a reference diet without DDGS and a diet containing either 0% DDGS, 10 or 20% light DDGS, or 10 or 20% dark DDGS. In Exp. 5, a total of 108 pigs (9.0 ± 0.2 kg of BW) were given a choice between a reference diet (0% DDGS and no flavor) and a diet without or with flavor and containing 0, 10, or 20% DDGS. In Exp. 1 and 2, DDGS and HP-DDG, respectively, linearly decreased (P < 0.01) pig preference. In Exp. 3, dark DDGS were preferred (P < 0.05) compared with light DDGS. In Exp. 4, preferences were linearly reduced (P < 0.01) with DDGS inclusion, and dark DDGS tended (P = 0.06) to be preferred compared with light DDGS. In Exp. 5, DDGS reduced preference (P < 0.01) and flavor reduced preference (P < 0.01) regardless of DDGS level. In Exp. 6, a total of 192 pigs (6.7 ± 0.1 kg of BW) were fed starter 1 diets without or with flavor for 1 wk. Subsequently, pigs were fed starter 2 and 3 diets (2 wk each) containing 0, 10, or 20% DDGS while continuing to receive their respective flavor treatment. Flavor addition during the starter 1 phase increased ADFI (P = 0.02), and DDGS inclusion tended to decrease ADG (P = 0.06) and decreased ADFI (P = 0.03) during the starter 2 phase. Volatile components in DDGS and HP-DDG varied greatly depending on the source. Nursery pigs preferred a diet without DDGS or HP-DDG, and this appeared to be unrelated to color differences between sources. Knowledge of volatile compounds that enhance or suppress the palatability of feed may lead to further development of feed additives for masking relatively unpalatable, albeit cost-effective, ingredients.

Fermented soybean meal as a vegetable protein source for nursery pigs: I. Effects on growth performance of nursery pigs.

Four experiments were conducted using 671 nursery pigs to evaluate fermented soybean meal (FSBM) as a new vegetable protein source for nursery pigs. In Exp. 1, a total of 192 pigs weaned at 19.2 +/- 0.3 d of age were fed 3 diets (8 pens per treatment) for 2 wk: a control diet (without FSBM) and 2 diets with 3 and 6% FSBM replacing soybean meal, followed by a common diet for the next 2 wk. In Exp. 2, a total of 160 pigs weaned at 21.6 +/- 0.2 d of age were fed 4 diets (5 pens per treatment) for 2 wk: a control diet (without FSBM but with 25% dried skim milk; DSM) and 3 diets with 3, 6, and 9% FSBM replacing DSM based on CP. Concentrations of CP, Lys, Met, Thr, and Trp were kept consistent among diets in Exp. 1 and 2. In Exp. 3, a total of 144 pigs weaned at 22.1 +/- 0.2 d of age were fed 3 diets (6 pens per treatment) for 2 wk: a control diet (without FSBM but with 40% DSM) and 2 diets with 5 and 10% FSBM replacing DSM based on CP. Concentrations of CP, Lys, Met, Thr, Trp, and lactose were kept consistent among diets. In Exp. 4, a total of 175 pigs weaned at 20.7 +/- 0.4 d of age were fed 5 diets (5 pens per treatment) for 3 wk: a basal diet [15.5% CP without plasma protein (PP) and FSBM], 2 diets (18.4% CP) with 3.7% PP or 4.9% FSBM, and 2 diets (21.2% CP) with 7.3% PP or 9.8% FSBM. Concentrations of Lys, Met, Thr, and Trp were kept consistent among diets with the same CP concentrations. Pigs had access to feed and water ad libitum and their BW and feed intake were measured weekly for all experiments. Use of up to 6% FSBM replacing soybean meal improved (P < 0.05) G:F and diarrhea scores of nursery pigs (Exp. 1). Use of up to 9% FSBM replacing DSM reduced (P < 0.05) ADG and G:F (Exp. 2). When lactose concentrations were equal, FSBM could replace up to 10% DSM without adverse effects on ADG and G:F (Exp. 3). Relative bioavailability of protein in FSBM to PP was 99.1% (Exp. 4). Collectively, FSBM can serve as an alternative protein source for nursery pigs at 3 to 7 wk of age, possibly replacing the use of DSM and PP but excluding the first week postweaning for PP when balancing for AA and lactose.