J. A. De Jong

Effects of dietary wheat middlings, corn dried distillers grains with solubles, and net energy formulation on nursery pig performance.

Four experiments were conducted to examine effects of dietary wheat middlings (midds), corn dried distillers grains with solubles (DDGS), and NE formulation on nursery pig performance and caloric efficiency. In Exp. 1, 180 nursery pigs (11.86 ± 0.02 kg BW and 39 d of age) were fed 1 of 5 diets for 21 d, with 6 pigs per pen and 6 replications per treatment. Diets were corn-soybean meal based and included 0, 5, 10, 15, or 20% wheat midds. Increasing wheat midds decreased (linear; P < 0.05) ADG and ADFI. Caloric efficiency improved (linear; P < 0.05) on both an ME (NRC, 1998) and NE (Sauvant et al., 2004) basis as dietary wheat midds increased. In Exp. 2, 210 pigs (6.85 ± 0.01 kg BW and 26 d of age) were fed 1 of 5 diets for 35 d, with 7 pigs per pen and 6 replications per treatment. Diets were corn-soybean meal based and contained 0, 5, 10, 15, or 20% wheat midds. Increasing wheat midds did not affect overall ADG or ADFI but decreased (quadratic; P < 0.013) G:F at 20%. Caloric efficiency for both ME and NE improved (quadratic; P < 0.05) as dietary wheat midds increased. In Exp. 3, 180 pigs (12.18 ± 0.4 kg BW and 39 d of age) were fed 1 of 6 experimental diets arranged in a 2 × 3 factorial with main effects of DDGS (0 or 20%) and wheat midds (0, 10, or 20%) for 21 d, with 6 pigs per pen and 5 replications per treatment. No DDGS × wheat midds interactions were observed, and DDGS did not influence ADG, ADFI, or G:F, but increasing dietary wheat midds decreased (linear; P < 0.05) ADG, G:F, and final BW. In Exp. 4, 210 pigs (6.87 kg BW and 26 d of age) were allotted to 1 of 5 dietary treatments, with 7 pigs per pen and 6 replications per treatment. Wheat middlings (0, 10, or 20%) were added to the first 3 diets without balancing for energy. In diets 4 and 5, soybean oil was added (1.4 and 2.8%) to 10 and 20% wheat midds diets to balance to the same NE as the positive control (0% wheat midds). Overall, no wheat midds × fat interactions occurred. Regardless of formulated energy value, caloric efficiency and G:F were poorer (P < 0.05) on an ME basis as wheat midds increased from 10 to 20% of the diet but did not change when calculated on an NE basis. Results of these experiments indicate that wheat midds may be fed up to 10 to 15% of the diet without negatively affecting nursery pig performance and with no interactive effects when fed in combination with DDGS. Also, formulating on an NE basis provided for similar performance with increasing dietary wheat midds compared with a corn-soybean meal control diet.

Effects of corn particle size, complete diet grinding, and diet form on finishing pig growth performance, caloric efficiency, carcass characteristics, and economics

A total of 855 pigs (PIC TR4 × Fast Genetics York × PIC Line 02), initially 56.54 lb BW) were used in a 111-d trial to evaluate the effects of corn particle size, complete diet grinding, and diet form (meal or pellet) on finishing pig growth performance, caloric efficiency, carcass characteristics, and economics. Pens of pigs were balanced by initial BW and randomly allotted to 1 of 5 dietary treatments with 9 replications per treatment. The same corn-soybean meal–based diets containing 30% dried distillers grains with solubles (DDGS) and 20% wheat middlings (midds) were used for all treatments. Diets were fed in four phases. Different processing techniques were used to create the 5 dietary treatments: (1) roller grinding the corn to approximately 650 μ with the diet fed in meal form; (2) hammer-mill grinding the corn to approximately 320 μ with the diet fed in meal form; (3) Treatment 2 but pelleted; (4) corn initially roller-mill ground to approximately 650 μ, then the complete mixed diet reground through a hammer mill to approximately 360 μ with the diet fed in meal form; and (5) Treatment 4 but pelleted.

Stability of four commercial phytase products under increasing thermal conditioning temperatures

Abstract Phytase is a feed-grade enzyme frequently added to swine diets to help improve the digestibility of phytate phosphorus. However, like any enzyme, it may be subject to heat damage when exposed to thermal processing. Therefore the objective of this experiment was to determine the stability of 4 commercial phytase products exposed to increasing thermal conditioning temperatures in the pelleting process. The 4 commercial products used were: Quantum Blue G (AB Vista, Plantation, FL); Ronozyme Hi Phos GT (DSM Nutritional Products, Parsippany, NJ); Axtra Phy TPT (Dupont, Wilmington, DE), and Microtech 5000 Plus (Guangdong Vtr Bio-Tech Co., Ltd., Guangdong, China). The phytase products were mixed as part of a corn-soybean meal-based swine diet at a concentration recommended by the manufacturer to provide a 0.12% aP release. Diets were exposed to each of 4 thermal conditioning temperatures (65, 75, 85, and 95°C) and the entire process repeated on 4 consecutive days to create 4 replicates. Samples were taken while feed exited the conditioner and before entering the pellet die. Samples were cooled to room temperature before being stored in plastic bags until analysis. Phytase stability was measured as the residual phytase activity (% of initial) at each conditioning temperature. There were no product × temperature interactions observed for conditioning temperature, conditioner throughput, or residual phytase activity. As target temperature increased, conditioner throughput decreased (linear; P < 0.001) and phytase activity decreased (linear; P < 0.001) for each product. Residual phytase activity decreased as conditioning temperature increased from 65 to 95°C at a rate of –1.9% for every 1°C increase in conditioning temperature. There was a significant phytase product (P < 0.001) main effect which was mainly driven by Microtech 5000 Plus having decreased (P < 0.05) phytase activity when compared to all other products at 65, 75, and 85°C. However at 95°C Axtra Phy TPT had greater (P < 0.05) residual phytase activity compared with Microtech 5000 Plus, with Quantum Blue G and Ronozyme Hi Phos intermediate. Increasing target conditioning temperatures decreased phytase stability regardless of product. In addition, Microtech 5000 Plus had decreased residual phytase activity (% of initial) when compared to all other products at 65, 75, and 85°C.

Stability of Four Commercial Phytase Products under Increasing Conditioning Temperature

A study was conducted to determine the stability of four commercial phytase products exposed to increasing conditioning temperatures. The four commercial products used were: Quantum Blue G (AB Vista, Plantation, FL); Ronozyme Hi Phos GT (DSM Nutritional Products, Parsippany, NJ); Axtra Phy TPT (Dupont, Wilmington, DE); and Microtech 5000 Plus (Guangdong Vtr Bio-Tech Co., Ltd., Guangdong, China). The phytase products were mixed as part of corn-soybean meal-based swine diet at a concentration recommended to provide a 0.12% aP release. All four diets were analyzed for phytase activity to establish baseline phytase activity for each product. Diets were then conditioned at four temperatures (149, 167, 185, and 203 F). The entire process was repeated on four consecutive days to create four replicates. Samples were taken while feed exited the conditioner and before entering the pellet die. Phytase stability was expressed as the residual phytase activity (% of baseline) at each conditioning temperature. No product × temperature interactions were observed for actual conditioning temperature, conditioner throughput, or residual phytase activity. As the target temperature increased the conditioning temperature increased (linear; P < 0.001) and conditioner throughput decreased (linear; P < 0.001). No evidence was observed for effects of phytase product on conditioning temperature or conditioner throughput. As target temperature increased, phytase activity decreased (linear; P < 0.001). Residual phytase activity decreased 1.07% for every 1 F increase in conditioning temperature between the target temperatures of 149 to 203 F. The product main effect was significant (P < 0.001). The Microtech 5000 Plus had decreased (P < 0.05) phytase activity when compared to all other products. There was no evidence for residual phytase differences between the Quantum Blue G, Ronozyme Hi Phos GT, or Axtra Phy TPT products. In the current experiment, target conditioning temperatures had a significant effect on phytase stability regardless of product, resulting in linear decreases in residual phytase activity as temperature was increased. However, Microtech 5000 Plus had decreased residual phytase activity (% of initial) when compared to all other products.

Effects of Feed Truck RPM on Pellet Quality, Unloading Speed, and Feed Line Location on Pellet Quality and Nutrient Segregation

Two separate studies were conducted at one commercial feed mill and six commercial wean-to-finish pig sites in northwest Iowa to determine the effects of feed truck unloading auger RPM on pellet quality and unloading time (Exp. 1) and the effects of feed line location on pellet quality and nutrient concentration of intact pellets and their fines (Exp. 2). For Exp. 1, feed samples were taken from each compartment of an 8-compartment, 24-ton Walinga (Walinga Inc., Guelph, Ontario) feed truck. Feed was unloaded using 3 unloading speeds as determined by the truck RPM of 900, 1,150, and 1,400. Each compartment was timed during unloading, and percentage fines and PDI were determined from each sample taken. The same truck was used 6 times, allowing for 16 replications per unloading speed and 6 replications per compartment. The compartment located closest to the truck cab was denoted as compartment 1, and the compartment located closest to the rear of the truck was denoted as compartment 8. An unloading speed × trailer compartment interaction (P = 0.031) was observed. The difference in unloading time for each compartment became progressively less, the closer the compartment was to the back of the truck. The percentage of fines formed was not significantly different among unloading speeds. The percentage of fines formed during unloading tended to increase (quadratic; P = 0.081) from the first to the eighth compartment, with the maximum percentage of fines formed occurring in the fifth compartment. In Exp. 2, pelleted feed was sampled as feed was unloaded into a commercial feed bin at 6 wean-to-finish barn sites. Each barn was equipped with 2 separate feed lines that transported feed from the bin into the barn. Feed samples were taken inside the barn at the feeder closest to the bin (20 ft), halfway from the bin (115 ft), and the farthest from the bin (250 ft) for each feed line. Samples were analyzed for percentage fines and PDI. During analysis, fines and complete pellets were separated, and a nutrient profile was determined for each. No interactions were observed between feed line location and nutrient profile of the fines and pellets. There was no effect of feed line location on pellet PDI, percentage fines, percentage fines formed, or pellet and fines nutrient profile. Fines had decreased (P < 0.05) CP and P but increased (P < 0.05) ADF, crude fiber, Ca, ether extract, and starch were observed when compared to the composition of pellets. In conclusion, feed flow from the compartments closer to the cab resulted in fewer fines formed from loading to unloading. Decreasing unloading speed significantly increased the amount of time taken to unload a feed truck. No differences were observed in the amount of fines formed for any of the unloading speeds. There appear to be no differences in pellet quality among feed line locations within a commercial wean to finish barn; however, there are significant differences in nutrient profile between fines and pellets.

Effects of Standardized Ileal Digestible Lysine on Nursery Pig Growth Performance

Lysine is the first limiting amino acid in swine diets, thus providing the appropriate level in the diet is critical to growth performance. Therefore, the objective of this study was to determine the standardized ileal digestible (SID) Lys requirement of nursery pigs from 15 to 35 lb. A total of 300 maternal line barrows (200 × 400, DNA, Columbus, NE; initially 14.9 ± 0.5 lb BW) were fed six experimental diets as part of a 21-d trial. Pigs were randomly allotted to pens at weaning based on BW, and were fed a common pelleted diet for 9 d after weaning. Pens were then randomly assigned to dietary treatments (10 pens/treatment with 5 pigs/pen) based on average pig weight. The six dietary treatments had increasing SID Lys (1.05, 1.15, 1.25, 1.35, 1.45, and 1.55%) and were achieved by increasing the inclusion of crystalline AA, allowing soybean meal to stay constant across dietary treatments. Experimental data were analyzed using general linear and non-linear mixed models with heterogeneous residual variances. Competing models included linear (LM), quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). For ADG, F/G, and IOFC, the best-fitting model was selected using Bayesian information criterion. Overall, increasing SID Lys improved (linear, P 1.55%) SID Lys, respectively. For F/G, the best-fitting model was the LM where F/G was improved up to at least 1.55% SID Lys. For income over feed cost (IOFC), the best-fitting model was the BLL, in which the maximum mean IOFC was estimated at 1.25% (95% CI: 1.14, 1.36%). In conclusion, the estimated SID Lys required for maximum mean ADG of these maternal line barrows was lower than the estimated mean SID Lys required for maximum mean F/G. This study provides evidence that different response variables can result in different estimates of the requirements; however, at least 1.25% SID Lys was needed to maximize IOFC.

Finely Grinding Cereal Grains in Pelleted Diets Offers Little Improvement in Nursery Pig Growth Performance

Five experiments were conducted to determine the effects of corn particle size and diet form on nursery pig performance and feed preference. In Exp. 1, 192 nursery pigs (PIC 327 × 1050; initially 14.7 lb and 26 d of age) were used in a 35-d experiment. Pens of pigs were balanced by BW and allotted to 1 of 4 treatments with 6 pigs per pen and 8 pens per treatment. The same corn and soybean meal-based diet formulation was used for all treatments. The 2 × 2 factorial consisted of the main effects of corn particle size (400 vs. 700 μm) and diet form (mash vs. pelleted). Pigs fed mash diets had improved overall ADG and greater ADFI during all periods (P 0.10) performance. In Exp. 2, a study utilized 96 pigs to evaluate feed preference of pigs consuming mash diets with either 400 or 700 μm corn. Pigs overwhelmingly (P 0.10) ADFI or F/G. Pigs fed pelleted diets from either 250 or 700 μm corn had poorer ADG than the intermediate treatments. Exp. 4 utilized 91 pigs to evaluate the preference of pigs consuming pelleted diets with either 250 or 700 μm corn from Exp. 3. Even in pelleted form, pigs preferred (P 0.10). Pelleting reduced (P 0.10). These studies suggest that there is little value to be gained by grinding corn to less than 700 microns if fed in pelleted form. Furthermore, our data suggest that, regardless if fed as mash or pellets, pigs prefer to consume diets manufactured with coarser ground corn if given the choice.

Effects of Grinding Corn through a 2-, 3-, or 4-High Roller Mill on Pig Performance and Feed Preference of 25- to 50-lb Nursery Pigs

A total of 410 pigs were used in two experiments to determine the effects of grinding corn through various roller mill configurations on feed preference and performance of nursery pigs. In Exp. 1, 320 pigs (DNA 400 × 200, initially 23.6 lb) were randomly allotted to 1 of 4 dietary treatments with 16 pens per treatment and 5 pigs per pen for a 21-d growth trial. The 4 dietary treatments used the same cornsoybean meal-based formulation that was mixed from the same batch of ingredients. Corn was ground through the same 4-high roller mill, but using different roller configurations. Experimental diets were: (1) feed with corn fraction ground to 650 μm using 2 sets of rolls (2-high), (2) feed with corn fraction ground to 495 μm using 3 sets of rolls (3-high), (3) feed with corn fraction ground to 340 μm using 4 sets of rolls in a fine grind configuration (4-high fine), and (4) feed with the corn fraction ground to 490 μm using 4 sets of rolls in a coarse grind configuration (4-high coarse). The same roller mill was used for all configurations with the appropriate lower rolls completely open when using the 2 or 3 sets of rolls configurations. In Exp. 2, 90 pigs (PIC 327 × 200, initially 27.0 lb) were randomly allotted to one of three diet comparisons to determine feed preference. The 3 diets used were from the 2-high roller mill configuration or the fine or coarse 4-high roller mill ground corn. Each pen contained 2 feeders, each containing 1 of the 3 treatment diets. The 3 diet comparisons tested were 2 vs. 4-high fine (1 vs. 3), 2-high vs. 4-high coarse (1 vs. 4), and 4-high fine vs. 4-high coarse (3 vs. 4). Feeders were rotated once daily within each pen for the 7-d study. There were 5 pigs per pen, and 6 pens per treatment. In Exp. 1, there were no differences (P > 0.05) in ADG, ADFI or F/G among roller mill configurations (Table 5). Similarly, no differences were observed (P > 0.05) for caloric efficiency or economics among roller mill configurations. In Exp. 2, when given a choice, pigs consumed 67% (P < 0.05) of the diet containing corn ground through the 2-high roller mill compared to only 33% from the diet containing 4-high fine corn (Table 6). There was no difference (P > 0.05) in feed consumption of 2-high roller mill corn and the diet manufactured with the 4-high roller mill in a coarse configuration (50.3 to 49.7%, respectively). However pigs consumed 63% (P < 0.05) of the diet manufactured using the 4-high roller mill in a coarse configuration and only 37% from the diet using the 4-high mill in a fine grind configuration. In the study, roller mill configuration had a significant impact on feed preference in nursery pigs, most likely as a result of differences in particle size. However, when nursery pigs did not have the choice between diets, there were no differences in gain, feed consumption, feed efficiency, or economics. Therefore, the study did not indicate a benefit in nursery pig performance or economic return when particle size was reduced below 650 μm.

Effects of Increasing Zinc from Two Different Sources on Nursery Pig Performance

A total of 360 weanling pigs (Line 400 × 200; DNA Genetics, Columbus, NE, initially 13.0 lb) were used in a 28-d trial to evaluate the effects of Zn source and level on nursery pig growth performance. Each treatment had 8 replicate pens with 5 pigs per pen. The 9 dietary treatments were arranged as 2 × 4 + 1 factorial and consisted of a control diet that contained 110 ppm Zn from ZnSO4 from the trace mineral premix or the control diet with 390, 890, 1,890, or 2,890 ppm added Zn from either TBZC (Intellibond Z; Micronutrients, Indianapolis, IN) or ZnO. This provided diets with a total of 500, 1,000, 2,000, or 3,000 ppm added Zn. Diets were fed in 3 phases from d 0 to 7, 7 to 21, and 21 to 28 with the first phase fed in pellet form and the others as meal. No Zn source by level interactions or Zn source differences were observed throughout this 28-d study. Overall, from d 0 to 28, increasing Zn increased (linear, P ≤ 0.05) ADG, ADFI, and d 28 BW. On d 28, fecal samples were collected from 3 pigs in each of the 8 pens per treatment and analyzed for DM content. There was a tendency (P = 0.08) for a Zn source by level interaction. As Zn from TBZC increased, fecal DM decreased, but for pigs fed increased Zn from ZnO there was no difference in fecal DM. In conclusion, up to 3,000 ppm Zn improved ADG and ADFI with no effect on F/G. There were no differences among pigs fed the different Zn sources, suggesting that either Zn source is effective at improving weanling pig growth performance.

Effects of Creep Feed Pellet Diameter on Suckling and Nursery Pig Performance

A total of 26 litters of pigs (PIC 327 × 1050; initially 7.1 lb and 10 d of age) were used in a 31-d growth trial to evaluate the effects of creep feed pellet diameter on suckling pig and subsequent nursery pig growth performance. On d 10 of the suckling phase, sows and their litters were allotted to one of two dietary treatments by parity and pig weight in a completely randomized design with 13 replications per treatment. Starting on d 10, pigs were fed the same creep feed formulation, but pelleted using either a 1/8 in. (small) or 1/2 in. (large) die. Chromic oxide was included in the diets as a fecal marker, and fecal swabs were taken twice a day on d 14, 17, and 21 to determine the percentage of pigs that were consuming creep feed. On d 21, pigs were weaned, re-allotted to nursery treatments for 21 d, and fed in two phases. Phase 1 (d 0 to 7 postweaning) treatment diets were the same diets as fed during the suckling period, with 50% of the pigs remaining on their previously allotted pellet diameter treatment. The other 50% of pigs were re-allotted to the opposite pellet diameter treatment in the nursery, creating a 2 × 2 factorial with the main effects of pellet diameter during suckling and pellet diameter during the nursery phase. A common meal Phase 2 diet (d 7 to 21) was fed to all pigs. During the suckling phase (d 10 to 21), litters of pigs fed the large creep feed pellet had decreased (P < 0.03) pre-weaning mortality and tended (P < 0.06) to have greater litter BW gain and litter ADG. There were no significant differences observed in pig BW, pig BW gain, litter CV, or pigs identified as creep feed eaters. From d 17 to 21 of suckling, pigs fed the large creep feed pellet had increased (P < 0.05) average daily creep feed intake. During the nursery phase, no interactions were observed for Phase 1 (d 0 to 7) when experimental diets were fed. Feeding a large pellet during the nursery phase, regardless of previous creep feed treatment, increased (P < 0.05) ADFI from d 0 to 4, 4 to 7, and 0 to 7. Pigs fed the large pellet in the suckling phase, regardless of pellet diameter fed during the nursery phase, had improved (P < 0.01) ADG from d 0 to 7 after weaning. Results from this study indicate that feeding a large creep feed pellet may be correlated with reduced preweaning mortality. However, there is no improvement on individual suckling pig growth performance or percentage of pigs eating creep feed between feeding either a small or large diameter pellet. Feeding a large creep feed pellet improved F/G for the entire nursery phase, and feeding a large nursery pellet increased ADFI during the first week in the nursery.