Effects of Different Corn Protein Sources and Level on Nursery Effects of Different Corn Protein Sources and Level on Nursery Pig Growth Performance and Feed Efficiency Pig Growth Performance and Feed Efficiency

Summary This experiment was conducted to determine the effects of 3 corn protein sources added at the expense of other specialty protein sources or corn on nursery pig growth performance and feed efficiency (F/G), and economic return. A total of 315 pigs (241 × 600; DNA, Columbus, NE; initially 12.1 lb) were used in a 35-d growth trial. There were 5 pigs per pen and 9 replicates per treatment. The treatments were structured as a randomized complete block design and arranged in a 3×2+1 factorial with main effects of corn protein source (CP1, CP2, and CP3; Cargill Inc., Blair, NE) and level (5 or 10%) plus a control diet. Treatment diets were fed in 2 phases (phase 1: d 0 to 7; phase 2: d 7 to 21) with a common diet fed from d 21 to 35. In phase 1, protein sources were added at the expense of fish meal in the 5% inclusion diets and replaced both fish meal and enzymatically treated soybean meal (HP300) for the 10% inclusion diets. In phase 2, protein sources were added at the expense of fish meal in the 5% inclusion diets, and both fish meal and corn in the 10% inclusion diets. All diets were fed in pellet form throughout the trial. In the treatment period (d 0 to 21), increasing corn protein sources decreased (linear, P < 0.05) average daily gain (ADG) and average daily feed intake (ADFI). Feed efficiency worsened (linear, P < 0.05) when pigs were fed increasing CP1 or CP2 and tended to worsen (linear, P < 0.10) when fed increasing CP3. The growth performance was poorest


Introduction
Protein sources, such as fish meal and enzymatically treated soybean meal, are relatively expensive, but beneficial feed ingredients in nursery pig diets.Therefore, using alternative protein sources to replace fish meal or enzymatically treated soybean meal without compromising growth performance might improve economic return.The corn processing industry removes starch from the corn kernel to produce concentrated starches, sweeteners, and texturizers.The remaining corn fraction is a corn protein product that contains high crude protein (>69% CP, as-fed).However, little data are available to determine the impact on nursery pig performance.Therefore, this study was designed to determine the effects on growth performance of weaned pigs fed diets containing 5 or 10% of three different corn protein sources.

Procedures
The Kansas State University Institutional Animal Care and Use Committee approved the protocols used in this experiment conducted at the Kansas State University Swine Teaching and Research Center in Manhattan, KS.Each pen (4 × 4 ft) was equipped with a 4-hole dry self-feeder, and a nipple waterer to provide ad libitum access to feed and water.
A total of 315 pigs (241 × 600; DNA, Columbus, NE; initially 12.1 lb) were weaned at approximately 21 d of age and placed in pens of 5 pigs each based on initial BW and gender.Pens of pigs were then randomly allotted to treatment in a randomized complete block design with BW as the blocking factor with 9 replicate pens per treatment.The treatments were structured as a randomized complete block design and arranged in a 3×2+1 factorial with main effects of corn protein source (CP1, CP2, and CP3; Cargill Inc., Blair, NE) and level (5 or 10%) and a control diet similar to that fed in commercial production (Table 1).Treatment diets were fed for 7 d in phase 1 followed by a 14-d feeding period in phase 2. In phase 1, corn protein sources were added at the expense of fish meal in the 5% inclusion diets, and both fish meal and enzymatically treated soybean meal (HP300) were added in the 10% inclusion diets.In phase 2, corn protein sources were added at the expense of fish meal in the 5% inclusion diets, and both fish meal and corn in the 10% inclusion diets.Nutrient loading values for the 3 corn protein sources were obtained from proximate analysis and previous digestibility studies that determined the standardized ileal digestibility (SID) AA and P coefficients, while the loading values for the other ingredients were provided by the supplier or obtained from the NRC. 4 For phase 3, all pigs were fed a common corn, soybean meal-based diet for 14 d.Diets were fed in pellet form in all three phases.Pen weights and feed disappearance were measured on d 0, 7, 14, 21, 27, and 35 to determine ADG, ADFI, and F/G.

Swine Day 2020
Phase 1 and 2 diets were manufactured at Cargill-Provimi, Brookville, OH.The phase 3 common diet was manufactured at Hubbard Feeds, Beloit, KS.All diets met or exceeded the NRC 4 nutrient requirement estimates.Diet samples were collected and thoroughly mixed within treatment before analysis for dry matter and crude protein (Kansas State University Swine Laboratory, Manhattan, KS).
Data were analyzed as a randomized complete block design for one-way ANOVA using the lmer function from the lme4 package in R program (version 3.5.2)5with pen considered the experimental unit, initial BW as blocking factor, and treatment as a fixed effect.Interactive and main effects of corn protein source (CP1, CP2, and CP3) and level (5 vs. 10%) were tested in addition to predetermined contrasts that compared the corn protein sources to each other, as well as the linear and quadratic response within corn protein source considering the control treatment as an inclusion level of "0."All results were considered significant at P ≤ 0.05 and marginally significant between P > 0.05 and P ≤ 0.10.

Results and Discussion
From d 0 to 7, there was no evidence of differences among 5 vs. 10% inclusions or among corn protein sources for any of the response criteria tested (Table 4 and 5).Pigs fed diets with CP1 tended to have poorer (P < 0.10) ADG and ADFI compared to those fed CP2.Pigs fed diets with CP2 tended to have poorer (P < 0.10) ADG and F/G as the level of CP2 increased.From d 7 to 21 and the overall treatment period (d 0 to 21), there was no evidence for corn protein level × source interactions.Pigs fed 5% of any corn protein source had better (P < 0.05) ADG and F/G compared to those fed 10% corn protein source.Pigs fed CP1 tended to have lower (P = 0.070) ADG and had lower (P < 0.05) ADFI from d 7 to 21 and had lower (P < 0.05) ADG and ADFI from d 0 to 21 compared to pigs fed diets with CP2.From d 7 to 21 and 0 to 21, pigs fed CP1 had lower (P < 0.05) ADG and ADFI compared to those fed CP3.There was no difference in performance observed during the treatment period between pigs fed CP2 and CP3.From d 7 to 21 and 0 to 21, increasing CP1 or CP2 worsened (linear, P < 0.05) ADG, ADFI, and F/G.From d 7 to 21 and 0 to 21 increasing CP3 worsened (linear, P < 0.05) ADG and ADFI, and tended to make F/G poorer (linear, P < 0.10).Day 21 BW was lower (linear, P < 0.05) when pigs were fed increasing levels of any corn protein source, and pigs fed CP1 had lower (P < 0.05) d 21 BW compared to CP2 or CP3.The responses observed to the 10% inclusion of corn protein sources were more severe than the 5% inclusion with 5% inclusion of CP2 and CP3 having performance similar to the controls.
In the common period (d 21 to 35), a tendency for an ADG interaction (P = 0.056) was observed because pigs previously fed 10% CP1 or CP3 had greater ADG compared to those fed 5% of their corn protein source, but pigs previously fed 5% CP2 had greater ADG than those fed 10% CP2.Feed efficiency was better (linear, P < 0.05) for pigs previously fed 10% of any corn protein source compared to those previously fed the 5% level, illustrating a compensatory response to removing the corn protein sources from Swine Day 2020 the diet.This may suggest a dietary component that may act to reduce intake.Pigs previously fed CP1 tended (P < 0.10) to have poorer ADFI, but improved F/G compared to those previously fed CP2, and had poorer (P < 0.05) ADFI but tended to have improved (P < 0.10) F/G compared to those fed CP3.Pigs previously fed increasing levels of CP1 tended (quadratic, P = 0.059) to have decreased then increased ADG and had reduced (linear, P < 0.05) ADFI and improved F/G.Pigs previously fed diets with increasing CP2 tended to have reduced (linear, P < 0.062) ADFI, and pigs previously fed diets with increasing CP3 tended to have improved (linear, P < 0.064) F/G, with both responses being driven by the performance of the 10% inclusion level as the 5% inclusion and the control were the same.
Overall (d 0 to 35), pigs fed CP1 tended to have decreased (P < 0.10) ADG and (P < 0.05) ADFI, but tended to have improved (P < 0.10) F/G compared to those fed CP2, and had decreased (P < 0.05) ADG and ADFI but tended to have improved (P < 0.10) F/G compared to those fed CP3.Pigs fed increasing CP1 or CP2 had reduced (P < 0.05) ADG, ADFI, and d 35 BW, and those fed increasing levels of CP3 tended to have lower (P < 0.10) ADFI and d 35 BW.The responses observed were primarily driven by the pigs fed the 10% inclusion level, as the pigs fed 5% had performance similar to that observed with the control pigs.
In summary, increasing amounts of these corn protein sources at the expense of other specialty protein sources decreased growth performance and d 21 BW of weanling pigs.Pigs fed CP1 had poorer performance compared to CP2 and CP3, while CP2 and CP3 elicited similar performance.The performance observed during the posttreatment common feeding period would suggest a compensatory growth and feed intake response, which might indicate the presence of a compound in the corn protein sources that limited intake.The observation that 5% inclusion of CP2 or CP3 resulted in similar performance as the control diet warrants further investigation to determine the optimum level of inclusion that optimizes performance and economics.
Brand names appearing in this publication are for product identification purposes only.No endorsement is intended, nor is criticism implied of similar products not mentioned.Persons using such products assume responsibility for their use in accordance with current label directions of the manufacturer.Ronozyme HiPhos GT 2700 (DSM Nutritional Products, Basel, Switzerland) provided 919 FTU per lb of feed and an expected P release of 0.14%.

5
A representative sample of each diet was collected from the feeders of each treatment, homogenized, and analyzed for proximate nutrients (Kansas State University Swine Laboratory, Manhattan, KS).DDGS = distillers dried grains with solubles.A total of 315 pigs (initially 12.1 lb) were used with 5 pigs/pen and 9 replicates/treatment. Treatment diets were fed from d 0 to 21.The common diet was fed to all pigs from d 21 to 35.The control treatment was used as an inclusion level of "0%" for linear and quadratic analysis.

Table 1 .
Phase 1 diet composition, (as-fed basis) 1 2CP1, CP2, and CP3 were provided by Cargill Inc., Blair, NE.3 Ronozyme HiPhos GT 2700 (DSM Nutritional Products, Basel, Switzerland) provided 919 FTU per lb of feed and an expected P release of 0.14%.4STTDP = standardized total tract digestible phosphorus.5Arepresentative sample of each diet was collected from the feeders of each treatment, homogenized, and analyzed for proximate nutrients (Kansas State University Swine Laboratory, Manhattan, KS).DDGS = distillers dried grains with solubles.

Table 4 .
Effects of 5% or 10% inclusion of 3 corn protein sources on nursery pig growth performance, feed efficiency, and economic return 1 3 BW = body weight.ADG = average daily gain.ADFI = average daily feed intake.F/G = feed-to-gain ratio.

Table 5 .
Additional probability values of nursery pig growth performance, feed efficiency, and economic return1,2