For any animal, the weaning process involves exposure to stress. For pigs in commercial production, it involves exposure to multiple stressors simultaneously, such as dietary change, maternal separation, moving to a new environment, mixing with unfamiliar pigs, exposure to handling and transportation, and exposure to new pathogens. Although weaning age in common swine production systems may range from 2-7 weeks (most commonly 3-4 weeks), this age range is all 'early' compared to natural weaning. The piglet at weaning is therefore often badly prepared to cope with the challenges that weaning presents. However, there are management and husbandry techniques that can be utilised to help minimize the impact of weaning, even in the most intensive housing and production systems in current use. For systems that can wean later, older piglets cope better. Periods away from the sow help to prepare the piglet for maternal separation and access to creep feed helps prepare the gastrointestinal tract and reduces reliance on the sow's milk. Allowing piglets from different litters to mingle before weaning, even by removing partitions between crates, can equip the piglets with social skills needed to cope with mixing at weaning. The provision of environmental enrichment before and after weaning confers many behavioural and production benefits. Early handling and positive interactions, even prior to routine processing procedures, can have long term positive impacts. Transport should be as little and as infrequent as possible, trying to reduce journey durations and maintain thermal comfort in particular. Time and effort spent on ameliorating any of these stressors will have short- and long-term benefits.

Two studies were conducted to determine the effects of feeder adjustment on growth performance of growing and finishing pigs. Both experiments were conducted at a commercial swine research facility in southwest Minnesota. In Exp. 1, a total of 1,170 barrows and gilts (PIC, initially 129.0 lb) were used in a 70-d study. Pigs were blocked by weight and randomly allotted to 1 of 5 treatments with 9 replications per treatment. The treatments were feeder settings of 1, 2, 3, 4, or 5, based on settings at the top of the STACO stainless steel dry feeders. Pigs were fed corn-soybean meal-based diets. From d 0 to 28, pigs fed from feeders with increasing feeder openings had increased (linear, P < 0.04) ADG and ADFI. For d 28 to 70, increasing feeder setting did not affect (P > 0.10) any growth performance traits. Overall (d 0 to 70), pigs fed from feeders with increasing feeder openings had increased (linear, P < 0.03) ADFI. Changing feeder setting did not affect (P > 0.18) ADG or F/G. In Exp. 2, a total of 1,250 barrows and gilts (PIC, initially 77.3 lb) were used in a 69-d study to determine the effect of feeder setting and diet type on growth performance of growing and finishing pigs. Pigs were blocked by weight and randomly allotted to 1 of 6 treatments with 8 replications per treatment. The treatments were arranged in a 3 × 2 factorial with main effects of STACO stainless steel dry feeder setting (1, 3, or 5) and diet type (corn-soybean mealor by-product-based (15% DDGS and 5% bakery by-product). Overall (d 0 to 69), there were no feeder setting × diet type interactions (P > 0.31) for growth performance. Diet type did not affect (P > 0.75) growth performance. Increasing feeder openings increased ADG (qu-adratic, P < 0.03) and ADFI (linear, P < 0.01). Feeder setting tended to influence (quadratic, P > 0.08) F/G with the best F/G at feeder set-ting of 3. In conclusion, feeding pigs from feeders with a more open feeder setting increased ADG and ADFI and tended to improve F/G at middle feeder settings compared with more closed feeder settings. With the dry feeders used in this study, feed should cover slightly more than half of the feed pan to avoid limiting pig performance.; Swine Day, 2008, Kansas State University, Manhattan, KS, 2008

A 28-d study was conducted to determine the influence of dietary glycerol on grow-finish pig performance. The experiment was conducted at a commercial swine research facility in southwest Minnesota. A total of 1,093 pigs (initially 171.3 lb, PIC) were blocked by weight and randomly allotted to 1 of 6 dietary treatments. Pigs were fed corn-soybean meal-based diets. The treatments were arranged in a 2 × 3 factorial with main effects of glycerol (0, 2.5, or 5%) and added fat (0 or 6%). Overall (d 0 to 28), there was a fat × glycerol interaction (P < 0.04) for ADFI. When 5% glycerol was added to diets without added fat, ADFI decreased; however, ADFI did not change when glycerol was added to diets containing 6% added fat. Pigs fed diets with added fat had improved (P < 0.01) ADG and F/G compared with pigs fed diets with no added fat. Increasing glycerol decreased ADG (linear, P < 0.02) and ADFI (linear, P < 0.04) and tended (linear, P < 0.08) to worsen F/G, a result of the negative effect of adding glycerol to diets without fat. In conclusion, 6% added fat improved ADG and F/G, but the glycerol used in this study decreased ADG and ADFI when added to diets without added fat.; Swine Day, 2008, Kansas State University, Manhattan, KS, 2008

Commercial crossbred mixed-sex pigs (n=120; initially 72.0 kg) were housed under either thermoneutral (TN) or cycling heat (HS) conditions simulating chronic summer heat with acute heat waves. Thermoneutral conditions were 18.9–16.7°C while HS consisted of chronic heat (30°C/26.7°C for 12h:12h) on days 24-72 except during periods of acute heat (32-33°C/29-30°C for 12h:12h) on days 21-24, 42-45, and 63-66. Treatments were arranged in a 2 × 2×2 factorial with main effects of environment (HS vs. TN), added Zn level (50 vs. 130 mg/kg available Zn added to corn-soybean meal based diet), and added Zn source (100% inorganic from ZnO vs. predominantly organic from Availa®Zn (Zinpro Corp, Eden Prairie, MN) consisting of 100% Zn from Availa®Zn at 50 mg/kg level or 62% Zn from Availa®Zn and 38% from ZnO at the 130 mg/kg level). Pens of 5 pigs each were blocked on initial bodyweight (BW) then randomly allotted to 1 of 8 temperature and diet treatments across a total of 10 complete replicate blocks. After a fixed time of 65 days, a representative pig closest to pen mean BW was selected from each pen and slaughtered at Purdue University Meats Laboratory (n=80). The HS pigs were lighter BW (P=0.039), yielded lighter carcasses (P=0.011; 96.1 kg HS vs. 99.3 kg TN), had less (P=0.032) backfat at the last rib, and tended to have less (P=0.054) leaf fat, smaller (P=0.062) loin eye area (LEA), and lower (P=0.088) dressing percentage. Carcasses of HS pigs exhibited improved carcass quality over TN pigs with higher (P=0.001) 24-hour loin pH, decreased (P=0.034) drip loss, and greater (P<0.050) subjective color and firmness scores. No main effects of Zn source, level, or interactions were observed (P>0.050). Forty additional HS pigs were slaughtered on day 72 after attaining a common weight compared to that of TN pigs previously slaughtered on day 65 (126.4 kg TN vs. 125.8 kg HS, P=0.674). Considered on a fixed weight schedule, 130 mg/kg Zn improved both live BW (P=0.017) and HCW (P=0.014) compared to 50 mg/kg Zn. Compared to 65-day TN pigs, 72-day HS pigs had a lower dressing percentage (P=0.012), tendency for lower (P=0.088) subjective marbling score, but more (P=0.033) BF at the last rib. Also, LEA under 72-day HS conditions was numerically greater when pigs received inorganic Zn but under 65-day TN conditions organic Zn numerically increased LEA (source×temperature, P=0.039). In conclusion, cyclic HS affected carcass quality but Zn level and source imparted negligible benefits.

The effects of pen location on swine thermoregulation and productivity were determined for 27 d during late summer. A total of 128 mixed sex pigs (1/2 Duroc × 1/4 Landrace × 1/4 Yorkshire) were randomly assigned to 16 pens in two grow-finish barns [n = 8 pens/barn; 57.4 ± 1.3 kg initial body weight (BW)]. Pen locations were pre-determined based on initial airflow (m/s) level [n = 4 high airflow (HAF) pens/barn and 4 low airflow (LAF) pens/barn]. High airflow and LAF pen locations were identical between each barn. Two sentinel gilts/pen were selected and vaginal temperature (TV) was measured daily in 10 min intervals using thermochron temperature loggers. Additionally, whole body skin temperature (TS) was measured with an infrared camera, and respiration rate (RR) was measured by counting flank movement of the sentinel gilts daily (0800h, 1500h). Pen airflow was measured daily (0800h, 1500h) with a vane anemometer. Ambient temperature (TA) and relative humidity (RH) within each pen were recorded daily in 10 min intervals. Average daily gain (ADG) and average daily feed intake (ADFI) were determined bi-weekly. Data were analyzed using PROC MIXED in SAS 9.4. Although airflow was lower overall (P = 0.04; 11%) in LAF compared to HAF pens, no differences (P > 0.56) in TA (27.63 ± 0.25°C; range 17.80-35.57°C) or RH (68.47 ± 0.46%; range 39.99-98.52%) were detected. An overall increase (P < 0.03) in TV (0.23°C), minimum TV (0.18°C), and maximum TV (0.29°C) was detected in LAF versus HAF pens. Similarly, from 0800-1900h and 2000-0700h, TV was greater overall (P < 0.02; 0.22 and 0.25°C, respectively) in LAF compared to HAF pens. A decrease in TS (P = 0.04) was observed in LAF (37.39 ± 0.14°C) compared to HAF (37.61 ± 0.14°C) pens. No RR differences (P > 0.60; 76 ± 4 bpm) were detected with any comparison. While no ADG or ADFI differences were detected (P > 0.16; 0.75 ± 0.02 kg/d and 2.26 ± 0.07 kg/d, respectively), feed efficiency was decreased (P = 0.04; 6%) in LAF compared to HAF pens. No barn differences were detected with any comparison. In summary, pigs located in LAF pens had greater body temperature and reduced feed efficiency despite similarities in TA and RH. These data have implications towards management of ventilations systems within swine facilities and the impact of pen-to-pen environmental variation on thermoregulation and productivity of pigs during hot summer months.

Recently, our lab determined that supplementing nursery diets with 0.20% l-glutamine improved health and productivity of weaned and transported piglets in a controlled environment. Therefore, study objectives were to determine the impact of replacing dietary antibiotics with 0.20% l-glutamine on growth performance and health status of piglets following weaning and transport in a production environment during the hot summer months. In July 2016, 246 mixed sex piglets (5.64 ± 0.37 kg BW; Duroc × [Landrace × Yorkshire]) were weaned (19 d of age), loaded onto a trailer, and transported for 12 h. During transport, ambient temperature (28.5 ± 0.3°C) and relative humidity (61.6 ± 1.1%) in the trailer were monitored in 5-min intervals, feed and water were withheld, and intra-abdominal temperature of 6 sentinel piglets was monitored every 10 min (39.7 ± 0.1°C). Following transport, 240 piglets were unloaded, blocked by BW, and randomly allotted to 1 of 3 dietary treatments (n = 10 pens/treatment [8 piglets/pen]). Treatments were dietary antibiotics (AB; chlortetracycline [441 mg/kg] + tiamulin [38.6 mg/kg]), no dietary antibiotics (NA), or 0.20% l-glutamine (GLU) fed for 14 d (Period 1). Following Period 1, all pigs were provided a common antibiotic-free diet until d 34 (Period 2). Data were analyzed using PROC MIXED in SAS 9.4. In Period 1, ADG tended to be greater (P = 0.06) in AB pigs (234 ± 11 g/d) compared with NA pigs (194 ± 11 g/d), with GLU pigs (213.0 ± 11 g/d) being intermediate and not different from AB and NA pigs. During Period 2, ADG increased (P = 0.03) in AB pigs (455 ± 9 g/d) versus NA pigs (420 ± 9 g/d); however, no differences were observed in GLU pigs (443 ± 9 g/d) compared with AB and NA pigs. Overall, AB and GLU increased ADG (P < 0.01; 359 ± 8 g/d) compared with NA (329 ± 8 g/d), but no differences were detected between AB and GLU pigs. Feed efficiency was improved overall (P = 0.03) for AB piglets (681 ± 13) compared with NA piglets (633 ± 13); however, no G:F difference was detected for GLU pigs (647 ± 13) versus AB and NA pigs. No ADFI differences (P > 0.11; 538 ± 13.1 g/d) were detected. Treatments for enteric challenges were greater overall (P = 0.02) in NA piglets (4.9 ± 1.5%) compared with GLU (1.5 ± 1.5%) and AB piglets (1.5 ± 1.5%). In conclusion, 0.20% l-glutamine supplementation improved piglet health and productivity similarly to dietary antibiotics following weaning and transport during the summer.

Sensory characteristics were evaluated on a total of 80 loins from pigs fed diets containing glycerol, ractopamine HCl (RAC), and a combination of glycerol and RAC during the last 28 d prior to harvest. A total of 1,054 pigs were blocked by weight and randomly allotted to 1 of 4 dietary treatments with 10 replications per treatment. Pigs were fed corn-soybean meal-based diets. Dietary treatments were arranged in a 2 × 2 factorial design with main effects of glycerol (0% or 5%) and RAC (0 or 6.75 g/ton). Pork loins from 1 randomly selected barrow and gilt from each pen were used for sensory analysis. There were no glycerol × RAC interactions or main treatment effects for cooking loss or Warner-Bratzler shear force (WBSF). Additionally, there were no glycerol × RAC interactions or main treatment effects for the sensory traits including myofibrillar tenderness, overall tenderness, pork flavor intensity, or off-flavor intensity. There was a glycerol × RAC interaction (P < 0.01) for the sensory trait of connective tissue amount. The interaction was a result of increased connective tissue amounts when glycerol was added to the diet without RAC but numerically decreased amounts when glycerol was fed in combination with RAC. In conclusion, feeding dietary glycerol or RAC singularly or in combination for 28 d prior to slaughter did not influence sensory characteristics of center-cut pork loin chops.; Swine Day, Manhattan, KS, November 19, 2009

A total of 360 weanling barrows (PIC 1050, 21 d of age and 13.0 lb) were used in a 35-d study to evaluate the effects of porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (M. hyo) vaccines on nursery pig growth performance. Two commercial PCV2 vaccines were evaluated in this study: (1) a 2-dose product, Circumvent PCV (Circumvent; Intervet/Schering-Plough Animal Health, Millsboro, DE) and (2) a 1-dose product, Ingelvac CircoFLEX (CircoFLEX; Boehringer Ingelheim Vetmedica, Inc, St. Joseph, MO). For the M. hyo vaccine, RespiSure (Pfizer Animal Health, New York, NY), a single 2-dose product, was used. At weaning (d 0), pens of pigs were blocked by average pig weight and randomly allotted to 1 of 6 treatments in a 3 × 2 factorial arrangement composed of a combination of PCV2 vaccine (Circumvent, CircoFLEX, or non-PCV2-vaccinated control) and M. hyo vaccine (RespiSure or non-M. hyo-vaccinated control). There were 5 pigs per pen and 12 pens per PCV2 × M. hyo vaccine treatment. All vaccines were administered according to label directions— CircoFLEX at weaning and Circumvent and RespiSure at weaning and 21 d later. Common diets were fed by phase to all pigs. There were no PCV2 × M. hyo vaccine interactions for any response criteria. Overall, pigs vaccinated with Circumvent had decreased ADG (P < 0.02) and ADFI (P ≤ 0.01) compared with CircoFLEX-vaccinated and control pigs, respectively. On d 35, Circumvent- vaccinated pigs weighed less (42.9 lb, P < 0.01) than pigs vaccinated with CircoFLEX (44.4 lb) or control pigs (44.4 lb). Pigs vaccinated with RespiSure had decreased ADG compared with control pigs (P ≤ 0.05) from d 14 to 21 and d 21 to 25. On d 35, RespiSure-vaccinated pigs tended to weigh less (43.5 lb, P = 0.06) and have lower ADFI (P = 0.06) than controls (wt = 44.3 lb). These data indicate that PCV2 and M. hyo vaccination can independently reduce feed intake and performance of nursery pigs and that the PCV2 vaccine effect is product dependent. Although PCV2 and M. hyo vaccines are known to improve finishing performance, their negative impact on nursery performance must be considered when implementing vaccine strategies.; Swine Day, Manhattan, KS, November 19, 2009

DDGS resulted in less tender chops with more off-flavors. Yet, the inclusion of glycerol in the diet decreased the intensity of off-flavors in pork chops.

A pilot experiment was conducted to determine the effects of feeding nonpregnant (open) sows a diet containing 50% dried distillers grains with solubles (DDGS) on growth and carcass fat quality. A total of 8 open sows were allotted to 1 of 2 diets by parity and BW. One diet was a standard corn-soybean meal-based gestation diet; the second diet was a corn-soybean meal-based diet that contained 50% DDGS. All sows were fed 5 lb/d of feed in a single feeding for 92 d. All sows were harvested on d 92 at the Kansas State University Meat Laboratory for determination of carcass fat quality. As expected, no differences in BW or backfat change were found (P > 0.62) for the feeding period. Additionally, no differences (P > 0.23) in lipid oxidation as measured by 2-thiobarbituric acid reactive substances (TBARS) assay were reported either initially or after 5 d of retail display for sows fed 50% DDGS compared with controls. Lipid oxidation increased (P < 0.003) as measured by TBARS assay for both treatments from d 1 to 5 as expected. Jowl fatty acid analysis revealed an increase in linoleic acid (P < 0.01), total polyunsaturated fatty acids (P < 0.01), and the ratio of polyunsaturated fatty acids to saturated fatty acids (P < 0.03). Also, there was a trend for increased jowl iodine value (P < 0.08) for sows fed 50% DDGS compared with the controls. In summary, feeding 50% DDGS to open sows for 92 d did not significantly affect BW, backfat, and lipid oxidation compared with controls. However, feeding 50% DDGS increased the concentration of linoleic acid and total polyunsaturated fatty acids and tended to increase jowl iodine value compared with controls.; Swine Day, 2008, Kansas State University, Manhattan, KS, 2008

Summary A total of 1,160 barrows (PIC, initially 68.4 lb) were used in a 97-d study to determine the influence of glycerol and dried distillers grains with solubles (DDGS) on growing-finishing pig performance, carcass characteristics, and fat quality. Pigs were blocked by weight and randomly allotted to 1 of 6 dietary treatments with 7 replications per treatment. Pigs were fed corn-soybean meal-based diets arranged in a 2 × 3 factorial with main effects of glycerol (0, 2.5, or 5%) and DDGS (0 or 20%). Overall (d 0 to 97), there were no glycerol × DDGS interactions (P > 0.12) for growth performance, carcass characteristics, and carcass fat iodine value (IV). Increasing glycerol did not affect (P > 0.14) ADG or F/G. Adding 20% DDGS to the diet did not affect ADG. However, pigs fed diets with 20% added DDGS had greater (P < 0.02) ADFI resulting in poorer (P < 0.01) F/G than pigs fed diets with no DDGS. For carcass characteristics, pigs fed increasing glycerol tended to have increased (linear, P < 0.11) yield. Pigs fed diets with added DDGS had increased (P < 0.01) jowl fat, belly fat, and backfat IV compared with pigs fed diets with no DDGS. However, increasing dietary glycerol tended to decrease (linear, P < 0.11) backfat IV. In conclusion, feeding pigs 20% DDGS worsened F/G and increased carcass fat IV, whereas feeding glycerol did not influence growth performance but tended to improve carcass yield and reduce backfat IV.

Two studies were conducted to determine the effects of feeder adjustment on growth performance of growing and finishing pigs. Both experiments were conducted at a commercial swine research facility in southwest Minnesota. In Exp. 1, a total of 1,170 barrows and gilts (PIC, initially 129.0 lb) were used in a 70-d study. Pigs were blocked by weight and randomly allotted to 1 of 5 treatments with 9 replications per treatment. The treatments were feeder settings of 1, 2, 3, 4, or 5, based on settings at the top of the STACO stainless steel dry feeders. Pigs were fed corn-soybean meal-based diets. From d 0 to 28, pigs fed from feeders with increasing feeder openings had increased (linear, P < 0.04) ADG and ADFI. For d 28 to 70, increasing feeder setting did not affect (P > 0.10) any growth performance traits. Overall (d 0 to 70), pigs fed from feeders with increasing feeder openings had increased (linear, P < 0.03) ADFI. Changing feeder setting did not affect (P > 0.18) ADG or F/G. In Exp. 2, a total of 1,250 barrows and gilts (PIC, initially 77.3 lb) were used in a 69-d study to determine the effect of feeder setting and diet type on growth performance of growing and finishing pigs. Pigs were blocked by weight and randomly allotted to 1 of 6 treatments with 8 replications per treatment. The treatments were arranged in a 3 × 2 factorial with main effects of STACO stainless steel dry feeder setting (1, 3, or 5) and diet type (corn-soybean meal- or by-product-based (15% DDGS and 5% bakery by-product). Overall (d 0 to 69), there were no feeder setting × diet type interactions (P > 0.31) for growth performance. Diet type did not affect (P > 0.75) growth performance. Increasing feeder openings increased ADG (qu-adratic, P < 0.03) and ADFI (linear, P < 0.01). Feeder setting tended to influence (quadratic, P > 0.08) F/G with the best F/G at feeder set-ting of 3. In conclusion, feeding pigs from feeders with a more open feeder setting increased ADG and ADFI and tended to improve F/G at middle feeder settings compared with more closed feeder settings. With the dry feeders used in this study, feed should cover slightly more than half of the feed pan to avoid limiting pig performance.; Swine Day, 2008, Kansas State University, Manhattan, KS, 2008

A 28-d study was conducted to determine the influence of dietary glycerol on grow-finish pig performance. The experiment was conducted at a commercial swine research facility in southwest Minnesota. A total of 1,093 pigs (initially 171.3 lb, PIC) were blocked by weight and randomly allotted to 1 of 6 dietary treatments. Pigs were fed corn-soybean meal-based diets. The treatments were arranged in a 2 × 3 factorial with main effects of glycerol (0, 2.5, or 5%) and added fat (0 or 6%). Overall (d 0 to 28), there was a fat × glycerol interaction (P < 0.04) for ADFI. When 5% glycerol was added to diets without added fat, ADFI decreased; however, ADFI did not change when glycerol was added to diets containing 6% added fat. Pigs fed diets with added fat had improved (P < 0.01) ADG and F/G compared with pigs fed diets with no added fat. Increasing glycerol decreased ADG (linear, P < 0.02) and ADFI (linear, P < 0.04) and tended (linear, P < 0.08) to worsen F/G, a result of the negative effect of adding glycerol to diets without fat. In conclusion, 6% added fat improved ADG and F/G, but the glycerol used in this study decreased ADG and ADFI when added to diets without added fat.; Swine Day, 2008, Kansas State University, Manhattan, KS, 2008

A total of 1,054 barrows and gilts (PIC, initially 207.8 lb) were used in a 28-d study to determine the influence of glycerol and ractopamine HCl (Paylean) on growing-finishing pig performance, carcass characteristics, and loin quality. The experiment was conducted in a commercial swine research facility in southwest Minnesota. Pigs were blocked by weight and randomly allotted to 1 of 4 dietary treatments with 10 replications per treatment. Pigs were fed corn-soybean meal-based diets. Dietary treatments were arranged in a 2 × 2 factorial with main effects of glycerol (0 or 5%) and ractopamine HCl (0 or 6.75 g/ ton). Overall (d 0 to 28), there were no glycerol × ractopamine HCl interactions (P > 0.10) observed for growth performance. Pigs fed dietary glycerol had improved (P < 0.04) F/G, but ADG and ADFI (P > 0.40) were not affected. Pigs fed diets with added ractopamine HCl had improved (P < 0.01) ADG and F/G with a tendency (P > 0.08) for lower ADFI than pigs fed diets with no ractopamine HCl. For carcass characteristics, there were glycerol × ractopamine HCl interactions observed (P < 0.05) for percent yield and fat free lean index (FFLI). Adding either ractopamine HCl or glycerol to the control diet increased yield and FFLI; however, there were no additive effects when the combination of glycerol and ractopamine HCl was fed. Pigs fed ractopamine HCl had increased (P < 0.04) HCW, yield, loin depth, and FFLI. There was a glycerol × ractopamine HCl interaction (P < 0.01) observed for loin chop drip loss. Loin chop drip loss was numerically improved when glycerol and ractopamine HCl were added separately to the control diet; however, loin chop drip loss numerically decreased when the combination of glycerol and ractopamine HCl was fed. Glycerol did not affect (P > 0.22) loin characteristics. Ractopamine HCl tended to improve (P < 0.08) sirloin chop a* (redness) color. Neither ractopamine HCl nor glycerol influenced iodine value of belly fat, jowl fat, or backfat. In conclusion, pigs fed 5% glycerol had improved F/G, whereas pigs fed ractopamine HCl had improved growth and carcass characteristics and a tendency for improved loin a* color.; Swine Day, 2008, Kansas State University, Manhattan, KS, 2008

The objective of this study was to determine the effects of diets containing crude glycerol on pellet mill production efficiency and nursery pig growth performance. In a pilot study, increasing crude glycerol (0, 3, 6, 9, 12, and 15%) in a corn-soybean meal diet was evaluated for pellet mill production efficiency. All diets were steam conditioned to 65.5 degrees C and pelleted through a pellet mill equipped with a die that had an effective thickness of 31.8 mm and holes 3.96 mm in diameter. Each diet was replicated by manufacturing a new batch of feed 3 times. Increasing crude glycerol increased both the standard (linear and quadratic, P < 0.01) and modified (linear, P < 0.01; quadratic, P <= 0.02) pellet durability indexes up to 9% with no further benefit thereafter. The addition of crude glycerol decreased (linear; P < 0.01) production rate (t/h) and production efficiency (kWh/t). In a 26-d growth assay, 182 pigs (initial BW, 11.0 +/- 1.3 kg; 5 or 6 pigs/pen) were fed 1 of 7 corn-soybean meal-based diets with no added soy oil or crude glycerol (control), the control diet with 3 or 6% added soy oil, 3 or 6% added crude glycerol, and 6 or 12% addition of a 50: 50 (wt/wt) soy oil/crude glycerol blend with 5 pens/diet. The addition of crude glycerol lowered (P < 0.01) delta temperature, amperage, motor load, and production efficiency. The addition of crude glycerol improved (P < 0.01) pellet durability compared with soy oil and the soy oil/crude glycerol blend treatments. Pigs fed increasing crude glycerol had increased (linear, P = 0.03) ADG. Average daily gain tended to increase with increasing soy oil (quadratic; P = 0.07) or the soy oil/crude glycerol blend (linear, P = 0.06). Adding crude glycerol to the diet did not affect G: F compared with the control. Gain: feed tended to increase with increasing soy oil (linear, P < 0.01; quadratic, P = 0.06) or the soy oil/crude glycerol blend (linear, P < 0.01; quadratic, P = 0.09). Nitrogen digestibility tended (P = 0.07) to decrease in pigs fed crude glycerol compared with pigs fed the soy oil treatments. Apparent digestibility of GE tended (P = 0.08) to be greater in the pigs fed soy oil compared with pigs fed the soy oil/crude glycerol blends. In conclusion, adding crude glycerol to the diet before pelleting increased pellet durability and improved feed mill production efficiency. The addition of 3 or 6% crude glycerol, soy oil, or a blend of soy oil and glycerol in diets for 11- to 27-kg pigs tended to increase ADG. For pigs fed crude glycerol, this was a result of increased ADFI, whereas, for pigs fed soy oil or the soy oil/crude glycerol, the response was a result of increased G: F.

Two studies were conducted to determine the fourth-limiting amino acid in swine diets containing NutriDense® corn. Both experiments were conducted at a commercial swine research facility in southwest Minnesota. In Exp. 1, 1,259 pigs (initially 82.1 lb, PIC) were used in a 28-d study. Pigs were blocked by weight, and were randomly allotted to one of six dietary treatments. Pigs were fed NutriDense corn-soybean meal-based diets. The treatments were 1) a positive control diet containing 0.15% L-lysine HCl and 0.015% added L-threonine; 2) a negative control diet with 0.45% L-lysine HCl, 0.085% added DLmethionine, and 0.15% added L-threonine; 3) treatment 2 with 0.05% L-isoleucine; 4) treatment 2 with 0.05% L-valine; 5) treatment 2 with 0.05% L-tryptophan; and 6) treatment 2 with a combination of 0.05% L-isoleucine, 0.05% L-tryptophan, and 0.05% L-valine. Pigs fed the positive control and the diet with the combination of added isoleucine, tryptophan, and valine had greater ADG (P<0.05) than all other treatments. Also, pigs fed added isoleucine or tryptophan had greater ADG (P<0.05) than pigs fed the negative control with those fed added valine being intermediate. Pigs fed the diet with the combination of added isoleucine, tryptophan, and valine had greater ADFI (P<0.05) then pigs fed the negative control. There were no significant differences in F/G.