Effects of Increasing Soybean Meal in Corn-Wheat Midds-Based Diets on Growth Performance and Carcass Characteristics of Late Finishing Pigs

A total of 786 pigs (PIC TR4 × (Fast LW × PIC L02); initially 213.2 lb ± 2.37 lb) were used to evaluate the effects of increasing soybean meal (SBM) in corn-wheat middsbased diets on growth performance of late finishing pigs. Pens of pigs were blocked by BW and randomly assigned to 1 of 5 treatments with 9 replications per treatment. Experimental diets were corn-based with 30% wheat midds. Soybean meal levels increased from 0 to 16% replacing added feed grade AA. Pens of pigs were weighed to evaluate ADG, ADFI, and F/G. Data were analyzed with the GLIMMIX procedure of SAS and pen was considered as the experimental unit. The statistical model considered fixed effects of dietary treatment, linear, quadratic, and cubic contrasts, and random effects of block. Overall, final BW of pigs increased (linear, P \u3c 0.05) as dietary SBM increased. Additionally, overall ADG and F/G improved as SBM increased (linear and cubic; P \u3c 0.05) with no differences in overall ADFI. Although diets were formulated to exceed minimum NRC nutrient requirement estimates, we suspect that the increased Trp:Lys ratio in the 16% SBM diet may explain the cubic responses observed. These results suggest that corn-soybean meal-based diets with 30% wheat midds for late finishing pigs should contain at least 4% SBM

The Effect of Increasing Valine, Isoleucine, and Tryptophan:Lysine Ratios on Pigs’ Growth Performance and Carcass Characteristics When Fed Diets with Increased Levels of Dietary Leucine:Lysine

A total of 4,076 pigs (initially 86.5 ± 1.24 lb) were used across 2 experiments to evaluate the effect of increasing ratios of Val, Ile, and Trp to Lys on pig growth performance and carcass characteristics in corn-soybean meal-DDGS-based diets containing increased levels of dietary Leu:Lys. In both experiments, the 4 dietary treatments were as follows: 1) high soybean meal and low feed grade amino acids (control); 2) low soybean meal and high feed grade amino acids, with Val:Lys, Ile:Lys, and Trp:Lys at 67, 55, and 18, respectively, (low ratio); 3) same as diet 2 except Val:Lys, Ile:Lys, and Trp:Lys increased to 72, 60, and 21, respectively, (medium ratio); and 4) same as diet 2 except Val:Lys, Ile:Lys, and Trp:Lys increased to 80, 65, and 23, respectively (high ratio). All diets contained 30% DDGS until pigs reached approximately 220 lb, and then 20% DDGS until trial completion. Overall ADG and average ADFI increased (AA ratio; linear, P \u3c 0.05) as Val, Ile, and Trp ratios increased from low to high. Pigs fed the control diet exhibited increased ADG when compared to pigs fed low ratio diets, while pigs fed medium and high ratio diets showed intermediate performance. In summary, the soybean meal level can be reduced, and synthetic amino acid levels increased in high DDGS diets as long as ratios of Val, Ile, and Trp to Lys are increased

Use of O3 Trial Feed to Reduce Omega-6:3 Ratio in PRRS-Virus Challenged Nursery Pigs

A total of 1,056 pigs (PIC TR4 × (Fast LW × PIC L02)), originating from an active PRRSV-positive sow farm, were used in a 46-d study to evaluate growth performance of nursery pigs fed diets containing increasing levels of O3 Trial Feed, a source of omega-3 fatty acids (alpha-linolenic acid). At placement in the nursery, pens of pigs were randomly assigned 1 of 4 dietary treatments with 22 pigs per pen and 12 replications per treatment. Treatments were arranged in a completely randomized design. Dietary treatments included increasing levels of O3 Trial Feed (0, 0.75, 1.5, and 3%) with pigs remaining on treatments throughout the 4 dietary phases over the 46-d study. Overall, pigs fed increased O3 Trial Feed had increased (linear, P \u3c 0.001) ADG and ADFI and improved (linear, P \u3c 0.001) F/G. Pigs fed increasing O3 Trial Feed also had decreased (linear, P = 0.027) total removals and mortalities. In summary, O3 Trial Feed improved growth performance and reduced mortality in PRRSV-positive nursery pigs

Use of Specialty Soy Products to Replace Poultry Meal and Spray-Dried Blood Plasma in Diets Provided to Nursery Pigs Housed in Commercial Conditions

A total of 2,260 pigs (PIC TR4 × [Fast LW × PIC L02]; initially 14.8 lb) were used to evaluate a specialty soy protein source as an alternative to poultry meal and spray-dried blood plasma on nursery pig performance in a commercial environment. At weaning, pigs were allotted to 1 of 5 dietary treatments based on initial weight in two research nurseries. In the first facility there were 20 pigs per pen and 10 pens per treatment. In the second facility, there were 21 pigs per pen and 12 replications per treatment for a total of 22 replications per treatment. Dietary treatments included a control diet containing 9.5% poultry meal (AV-E Digest, XFE Products, Des Moines, IA) and 4.13 (phase 1) or 2.75% (phase 2) spray-dried blood plasma (Appetein, APC Inc., Ankeny, IA). The four additional diets were set up in a 2 × 2 factorial with a novel soy protein concentrate (AX3 Digest; Protekta; Plainfield, IN) or fermented soybean meal (MEPro; Prairie Aquatech; Brookings, SD) replacing poultry meal or poultry meal and spray-dried blood plasma in the control diet. Pigs were fed experimental diets during phase 1 (d 0 to 7) and phase 2 (d 7 to 21). Following phase 2, pigs were fed a common diet for an additional 21 d (d 21 to 42). During the experimental period (d 0 to 21), pigs fed the novel soy protein concentrate had improved (P \u3c 0.001) F/G with no differences in ADG or ADFI compared to pigs fed fermented soybean meal. During the experimental period (d 0 to 21) and overall (d 0 to 42), pigs fed soy protein as a replacement to poultry meal had increased (P ≤ 0.016) ADG and ADFI compared to pigs fed the control diet. During the experimental period (d 0 to 21), pigs fed soy protein as a replacement to spray-dried blood plasma had improved (P = 0.044) F/G compared to pigs fed soy protein without replacing spray-dried blood plasma, with no differences in ADG or ADFI. In summary, utilizing a specialty soy protein source as a replacement for poultry meal improved growth performance. Replacing poultry meal and spray-dried blood plasma with soy protein improved feed efficiency when treatment diets were fed, but not overall. In addition, the novel soy protein concentrate improved feed efficiency compared to fermented soybean meal during the experimental period with no effect on ADG or ADFI

Influence of Feed Grade Amino Acid Inclusion Level in Late Nursery and Grower Diets Fed to Pigs from 21 to 75 lb

A total of 912 pigs (PIC TR4 × (Fast LW × PIC L02); initially 21.4 lb) were used in a 43-d trial to evaluate the influence of feed grade amino acid in diets containing 30% dried distillers grains with solubles (DDGS) fed to pigs from 21 to 75 lb. Pigs were randomly assigned to pens (19 pigs per pen) and pens were randomly allotted in weight blocks to 1 of 4 dietary treatments with 12 pens per treatment. Dietary treatments contained low, medium, high, or very high additions of feed grade amino acids with L-lysine added at approximately 0.25, 0.40, 0.55, and 0.70% of the diet. This corresponded to 15, 24, 33, and 42% of the standardized ileal digestibility (SID) lysine coming from L-lysine. All other amino acids were added as needed to meet minimum desired ratios relative to lysine (60% Ile; 58% Met and Cys; 65% Thr; 19% Trp; and 72% Val). Predetermined orthogonal contrasts were used to evaluate linear or quadratic effects based on the feed grade lysine to total lysine ratio. Overall (d 0 to 43), there was an increase (quadratic, P \u3c 0.020) in average daily gain (ADG) and average daily feed intake (ADFI), with pigs fed increasing feed grade amino acids having increased gain and feed intake up to the high addition of feed grade amino acids and decreasing for pigs fed the very high diet. For overall feed efficiency (F/G), pigs fed the medium feed grade amino acids had improved F/G (P = 0.002) compared to pigs fed the high and very high levels of feed grade amino acids, with the pigs fed the low feed grade amino acids intermediate. As feed grade amino acids increased in the diet, blood urea nitrogen decreased (linear, P = 0.001) on d 21 and 43. In summary, as the percentage of L-lysine as a proportion of total SID lysine increased in the diet from 15 (Low) to 24% (Medium), ADG and F/G improved; however, as the L-lysine as a proportion of total SID lysine in the diet increased to greater than 24%, F/G worsened

The Effect of Different Bone and Analytical Methods on the Assessment of Bone Mineralization to Dietary Phosphorus, Phytase, and Vitamin D in Finishing Pigs

Eight hundred eighty-two pigs (initially 73.2 ± 0.7 lb) were used to evaluate the effects of different bones and analytical methods on the assessment of bone mineralization response to dietary P and vitamin D in growing-finishing pigs. Pens of pigs (20 pigs per pen) were randomized to 1 of 5 dietary treatments in a completely randomized design with 9 pens per treatment. Treatments were formulated to have varying levels of P, phytase, and vitamin D to potentially provide wide differences in bone characteristics. After feeding diets for 112 d, nine pigs per treatment were euthanized for bone, blood, and urine analysis. There were no significant differences for final BW, ADG, ADFI, F/G (P \u3e 0.10), or bone ash (bone ash × bone interaction, P \u3e 0.10) regardless of the ashing method. The response to treatment for bone density and bone mineral content was dependent upon the bone (density interaction, P = 0.053; mineral interaction, P = 0.078). There were no treatment differences for bone density and bone mineral content for metacarpals, fibulas, and 2nd rib (P \u3e 0.05). For 10th rib bone density, pigs fed industry levels of P and vitamin D had increased (P \u3c 0.05) bone density compared to pigs fed NRC levels with phytase, with pigs fed deficient P, NRC levels of P with no phytase, and extra 25(OH)D3 vitamin D (HyD) intermediate. Pigs fed extra vitamin D from HyD had increased (P \u3c 0.05) 10th rib bone mineral content compared to pigs fed deficient P and NRC levels of P with phytase, with pigs fed industry P and vitamin D, and NRC P with monocalcium intermediate. In summary, bone density and bone mineral content responses varied depending on the bone. The difference between bone ash procedures was more apparent than the differences between diets. Differences in bone density and mineral content in response to P and vitamin D were most apparent with the 10th ribs

Dynamics of soil organic carbon following land-use change: insights from stable C-isotope analysis in black soil of Northeast China

Intensive soil tillage is a significant factor in soil organic matter decline in cultivated soils. Both cultivation abandonment and foregoing tillage have been encouraged in the past 30 years to reduce greenhouse gas emissions and soil erosion. However, the dynamic processes of soil organic carbon (SOC) in areas of either continuous cultivation or abandonment remain unclear and inconsistent. Our aims were to assess and model the dynamic processes of SOC under continuous tillage and after cultivation abandonment in the black soil of Northeast China. Soil profiles were collected of cultivated or abandoned land with cultivation history of 0–100 years. An isotope mass balance equation was used to calculate the proportion of SOC derived from corn debris (C4) and from natural vegetation (C3) to deduce the dynamic process. Approximately 40% of SOC in the natural surface soil (0–10 cm) was eroded in the first 5 years of cultivation, increasing to about 75% within 40 years, before a slow recovery. C4 above 30 cm soil depth increased by 4.5%–5% or 0.11–0.12 g·kg−1 on average per year under continuous cultivation, while it decreased by approximately 0.34% annually in the surface soil after cultivation abandonment. The increase in the percentage of C4 was fitted to a linear equation with given intercepts in the upper 30 cm of soil in cultivated land. A significant relationship between the change of C4 and time was found only in the surface soil after abandonment of cultivation. These results demonstrate the loss and accumulation of corn-derived SOC in surface black soil of Northeast China under continuous tillage or cultivation abandonment