Effects of Bovine Plasma and Pharmacological Zinc Level on Effects of Bovine Plasma and Pharmacological Zinc Level on Nursery Pig Growth Performance and Fecal Characteristics Nursery Pig Growth Performance and Fecal Characteristics

Summary A total of 300 pigs (241 × 600, DNA; initially 12.9 lb) were used in a 38-d trial to evaluate the effect of Zn level and bovine plasma in nursery pig diets. At the time of placement, pens of pigs were weighed and allotted to 1 of 4 dietary treatments in a randomized complete block design with barn as the blocking factor. There was a total of 60 pens with 5 pigs per pen and 15 replicates per dietary treatment. The treatments were arranged in a 2 × 2 factorial with main effects of Zn level (high and low) and spray-dried bovine plasma inclusion (with or without; APC Inc., Ankeny, IA). Diets with pharmacological levels of Zn had 3,000 and 2,000 ppm of Zn in phase 1 and 2 diets, respectively. Diets with low level of Zn had 110 ppm of Zn in phase 1 and 2 diets. Bovine plasma replaced a portion of a fermented vegetable protein source (MEpro, Prairie Aquatech, Brookings, SD) in diet formulation with bovine plasma included at 5% and 2% in the phase 1 and 2 diets, respectively. Treatment diets were fed in 2 phases (phase 1: d 0 to 9; phase 2: d 9 to 24) with a common diet (110 ppm of Zn without plasma) fed from d 24 to 38. Fecal samples and scores were collected on d 9 and 24 for determination of fecal dry matter. There was no evidence of Zn × plasma interactions ( P > 0.10) throughout the trial for any growth criteria. From d 0 to 9, pigs fed bovine plasma tended to have improved ADG ( P = 0.066


Introduction
Pharmacological levels of Zn between 2,000 to 3,000 ppm in initial nursery diets reduce post-weaning diarrhea and improve growth performance. 3However, high Zn in manure causes environmental and antimicrobial resistance concerns.Spray-dried animal plasma is often used in swine post-weaning diets to improve growth performance and gastrointestinal development.Spray-dried animal plasma contains protein and minerals.The protein fraction is largely comprised of albumins and globulins (e.g., IgG) which have biological functions in animals, such as maintaining the buffering capacity of the blood and immune function. 4Including animal plasma in feed has been found to improve the intestinal health and feed intake due to improved diet palatability. 4These benefits may allow for improved animal health and thus reduce the need to include pharmacological levels of Zn in starter nursery diets.Therefore, the objective of this study was to determine the effects of including spray-dried bovine plasma with or without pharmaceutical level of Zn in phase 1 and 2 nursery diets on growth performance, fecal score, and fecal dry matter during the post-weaning period.

Procedures
The Kansas State University Institutional Animal Care and Use Committee approved the protocol 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.

Animals and diets
A total of 300 pigs (241 × 600, DNA; initially 12.9 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 barn as the blocking factor with 15 replicate pens per treatment.The treatments were structured as a randomized complete block design and arranged in a 2 × 2 factorial with main effects of Zn level (high or low) and bovine plasma inclusion (with or without; APC Inc., Ankeny, IA).Treatment diets were fed in 2 phases (phase 1: d 0 to 9; phase 2: d 9 to 24; Table 1) with a common diet (110 ppm of Zn without plasma) fed from d 24 to 38.High Zn diets had 3,000 and 2,000 ppm of Zn in phase 1 and 2, respectively.Low Zn diets had 110 ppm of Zn in phase 1 and 2 diets.A fermented vegetable protein (MEpro, Prairie Aquatech, Brookings, SD) was included in phase 1 and 2 diets at 7 and 2%, respectively.In order to maintain a constant soybean meal level in all diets, bovine plasma replaced the fermented vegetable protein on an equal lysine basis at 5 and 2% in the phase 1 and 2 diets, respectively.Nutrient loading values for the 2 protein sources were obtained from the manufacturers and used in diet formulation while all other ingredient values were obtained from the NRC. 5 For phase 3, all pigs were fed a common corn and soybean meal-based diet for 14 d.Diets were fed in pellet form in phase 1, and meal form in phases 2 and 3. Pen weights and feed disappearance were measured on d 0, 9, 17, 24, 31, and 38 to determine ADG, ADFI, and F/G.Fecal samples for the determination of fecal dry matter and scores were collected on d 9 and 24.Fecal samples were collected from the same three medium weight pigs from each pen.After collection, fecal samples were dried at 55°C (131°F) in a forced air oven for 48 h and the ratio of dried to wet fecal weight determined the fecal dry matter.Fecal scores were assigned to each pen by the same three observers.Fecal scores were assigned based on a 5-point scale, with 1 = watery feces; 2 = soft unformed feces; 3 = soft moist feces; 4 = firm formed feces; and 5 = hard feces.
Phase 1 and 2 basal diets were manufactured at Hubbard Feeds, Beloit, KS.The basal diets were mixed with remaining ingredients (e.g., AAs, specialty protein sources, ZnO) at the Kansas State University O.H. Kruse Feed Technology Innovation Center (Manhattan, KS) to make the 4 treatment diets.The phase 3 common diet was manufactured at Hubbard Feeds, Beloit, KS.All diets met or exceeded the NRC5 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).

Statistical analysis
Data were analyzed as a randomized complete block design for two-way ANOVA.Pen was considered the experimental unit.Barn was the blocking factor.Treatments were used as the fixed effect.Interactive and main effects of Zn level (high or low) and bovine plasma (with or without) were tested.For growth performance and fecal DM, data were analyzed using the lmer function from the lme4 package (R Core Team, 2019).Fecal dry matter and fecal score were analyzed as repeated measures representing multiple observations in each pen over time, and pens were included in the model as random intercepts to account for subsampling attributed to the multiple observations on each day.Plasma, Zn, day, and the associated interactions were considered fixed effects within the statistical model.For fecal score, data were analyzed as categorical outcomes using a generalized linear mixed model with a multinomial response distribution using a cumulative logit link function.Data were fit using the GLIMMIX procedure of SAS (v.9.4, SAS Institute, Inc., Cary, NC), and are summarized using the FREQ procedure and reported as percentage of observations within each fecal score category by treatment and day.For all growth and fecal data, Tukey adjustment was used for multiple comparisons.All results were considered significant at P ≤ 0.05 and marginally significant at 0.05 < P ≤ 0.10.

Growth performance
There was no evidence of Zn × plasma interactions (P > 0.10) throughout the trial (d 0 to 38; Table 2).
From d 0 to 9, pigs fed bovine plasma had improved d 9 BW (P = 0.035; Table 3), and ADFI (P < 0.001) and tended to have improved ADG (P = 0.066) compared to pigs fed diets without bovine plasma.Also, pigs fed high Zn had improved (P ≤ 0.018) d 9 BW, ADG, and F/G compared to pigs fed low Zn diets.
From d 9 to 24, pig fed high Zn had improved (P < 0.001) d 24 BW, ADG, and ADFI.There was no evidence of difference (P > 0.10) in d 24 BW, ADG, ADFI, and F/G between pigs fed diets with or without bovine plasma.
During the overall treatment period (d 0 to 24), pigs fed high Zn had improved (P ≤ 0.009) d 24 BW, ADG, ADFI, and F/G compared to pigs fed low Zn.There was no evidence of difference (P > 0.10) in d 24 BW, ADG, ADFI, and F/G between pigs fed diets with or without bovine plasma.
From d 24 to 38 when pigs were fed a common diet, pigs previously fed high Zn from d 0 to 24 had reduced ADFI (P = 0.046) compared to pigs fed low Zn diets.There was no evidence of difference (P > 0.10) in ADG, ADFI, and F/G between pigs previously fed diets with or without bovine plasma.
For the overall period (d 0 to 38), pigs fed high Zn from d 0 to 24 had improved (P ≤ 0.029) final BW, ADG, and F/G compared to pigs fed low Zn.There was no evidence of difference (P > 0.10) in ADG, ADFI, and F/G between pigs fed diets with or without bovine plasma.

Fecal dry matter and fecal score
For fecal DM, there was no plasma × Zn × day interaction (P = 0.829; Table 4).There was a tendency for a plasma × Zn interaction (P = 0.067; Table 5) to be observed, where pigs fed high Zn had increased (P < 0.05) fecal DM compared to pigs fed low Zn when bovine plasma was added in the diets, while this Zn effect was not significant (P > 0.05) when fed in diets without plasma.Moreover, there was a significant Zn × day interaction (P = 0.032; Table 6) observed where pigs fed low Zn had increased (P < 0.05) fecal DM on d 24 compared to d 9, while fecal DM of pigs fed high Zn had no evidence of difference (P > 0.05) between d 9 and 24.Fecal DM of the high Zn diets was higher than those observed in low Zn diets for both days.
For fecal score (Figure 1), there was no evidence of plasma × Zn × day interaction; plasma × Zn interaction; plasma × day interaction; or plasma main effect (P > 0.10).There was a tendency for a Zn × day interaction (P = 0.085) to be observed where pigs fed low Zn had increased frequency of scores with firmer feces on d 24 compared to d 9, while pigs fed high Zn diets had similar fecal frequency on d 9 and 24.Pigs fed high Zn had higher (P < 0.001) frequency of scores with firmer feces.
In summary, pigs fed pharmacological levels of Zn had improved nursery performance whereas pigs fed bovine plasma had improved performance for the first 9 days postweaning.Moreover, high Zn improved fecal characteristics, while bovine plasma had negative effects on fecal DM when fed in low Zn diets.The results of this study indicate that the benefits of pharmacological levels of zinc could not be replaced by bovine plasma alone.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.A total of 300 pigs (initially 12.9 lb) were used with 5 pigs/pen.Each mean represents 15 observations.Treatment diets were fed from d 0 to 24.Common diet was fed to all pigs from d 24 to 38.The inclusion levels of bovine plasma were 5 and 2% in phase 1 and 2 diets, respectively.The inclusion levels of Zn were 3,000 and 2,000 ppm in phase 1 and 2 diets, respectively.

Swine Day 2022
Kansas State University Agricultural Experiment Station and Cooperative Extension Service A total of 300 pigs (initially 12.9 lb) were used with 5 pigs/pen.Each mean represents 30 observations.Treatment diets were fed from d 0 to 24.Common diet was fed to all pigs from d 24 to 38.The inclusion levels of bovine plasma were 5 and 2% in phase 1 and 2 diets, respectively.The inclusion levels of Zn were 3,000 and 2,000 ppm in phase 1 and 2 diets, respectively.A total of 300 pigs (initially 12.9 lb) were used with 5 pigs/pen.Each mean represents 45 observations.Treatment diets were fed from d 0 to 24.Common diet was fed to all pigs from d 24 to 38.The inclusion levels of bovine plasma were 5 and 2% in phase 1 and 2 diets, respectively.The inclusion levels of Zn were 3,000 and 2,000 ppm in phase 1 and 2 diets, respectively.Fecal samples were collected from the same three medium weight pigs from each pen.After collection, fecal samples were dried at 55°C (131°F) in a forced air oven for 48 h and the ratio of dried to wet fecal weight determined the fecal dry matter.A total of 300 pigs (initially 12.9 lb) were used with 5 pigs/pen.Each mean represents 90 observations.Treatment diets were fed from d 0 to 24.Common diet was fed to all pigs from d 24 to 38.The inclusion levels of bovine plasma were 5 and 2% in phase 1 and 2 diets, respectively.The inclusion levels of Zn were 3,000 and 2,000 ppm in phase 1 and 2 diets, respectively.ab Means with different superscripts differ (P < 0.05).A total of 300 pigs (initially 12.9 lb) were used with 5 pigs/pen.Each mean represents 90 observations.Treatment diets were fed from d 0 to 24.Common diet was fed to all pigs from d 24 to 38.The inclusion levels of bovine plasma were 5 and 2% in phase 1 and 2 diets, respectively.The inclusion levels of Zn were 3,000 and 2,000 ppm in phase 1 and 2 diets, respectively.abc Means with different superscripts differ (P < 0.05).A total of 300 pigs (initially 12.9 lb) were used with 5 pigs/pen.Each mean represents 180 observations.Treatment diets were fed from d 0 to 24.Common diet was fed to all pigs from d 24 to 38.The inclusion levels of bovine plasma were 5 and 2% in phase 1 and 2 diets, respectively.The inclusion levels of Zn were 3,000 and 2,000 ppm in phase 1 and 2 diets, respectively.Figure 2. Fecal score frequency by treatment.A total of 300 pigs (initially 12.9 lb) were used with 5 pigs/pen.Each bar represents 90 observations.Treatment diets were fed from d 0 to 24.The inclusion levels of bovine plasma were 5 and 2% in phase 1 and 2 diets, respectively.The inclusion levels of Zn were 3,000 and 2,000 ppm in phase 1 and 2 diets, respectively.Fecal scores were assigned to each pen by the same 3 observers.Fecal scores were assigned based on a 5-point scale, with watery feces, soft unformed feces, soft moist feces, firm formed feces, and hard feces.There were no hard feces observed.Frequency was determined by the number of each fecal score over the total number of observations of each treatment.

Table 1 .
Diet composition, (as-fed basis) 1 Kansas State University Agricultural Experiment Station and Cooperative Extension Service

Table 2 .
Effects of bovine plasma and Zn level on nursery pig growth performance 1

Table 3 .
Main effects of bovine plasma and Zn level on nursery pig growth performance 1

Table 4 .
Interactive effects of bovine plasma, Zn level, and day on nursery pig fecal dry matter 1

Table 5 .
Interactive effects of bovine plasma and Zn level on nursery pig fecal dry matter 1

Table 6 .
Interactive effects of Zn level and day on nursery pig fecal dry matter 1

Table 7 .
Main effects of bovine plasma, Zn level, and day on nursery pig growth performance 1 Swine Day 2022 Kansas State University Agricultural Experiment Station and Cooperative Extension Service Zn × Plasmas, P = 0.424 Zn, P < 0.001 Plasmas, P = 0.324