This study investigated the effect of crude protein (CP) and non-essential amino acids (NEAA) supplementation on growth performance and gut health of nursery pigs. Ninety weaned pigs (22 days old; 7.5 ± 0.7 kg BW; AGPIC 415 × Camborough) barrows and gilts, were distributed in a randomized complete block design (BW as block) to three dietary treatments fed for 14 days: 1) 24% CP, 2) 18% CP, and 3) 18% CP + NEAA, including 5 g/kg L-arginine and 10 g/kg L-glutamate + L-glutamine (AminoGut, Ajinomoto, São Paulo, Brazil). There were ten replicates per treatment and three pigs per pen. A corn-soybean meal-based diet was formulated to have 3,400 kcal/kg of metabolizable energy and 1.45 g/kg of standardized ileal digestible lysine. Crystalline amino acids, L-Lys, L-Thr, DL-Met, L-Trp, L-Val, L-Ile, L-His, and L-Leu were used (if necessary) to satisfy the ideal amino acid profile according to the Brazilian Tables for Poultry and Swine (Rostagno et al., 2017). On day 14, pigs were weighed and then euthanized to collect duodenum, jejunum, and ileum tissue. Growth performance, diarrhea incidence, intestinal morphology, goblet cells, and Peyer’s patches were evaluated. Data were analyzed using the Mixed procedure in SAS 9.4 and means were compared by Tukey’s test. Pigs fed 24% CP diet had improved (P < 0.05) G:F compared to 18% CP and 18% CP + NEAA (Table 1). There was no effect (P > 0.05) of dietary treatments on ADFI, ADG, BW, and diarrhea incidence. In the duodenum, pigs fed 18% CP + NEAA diets had greater (P < 0.05) villus height compared to the 24% CP and 18% CP (427 to 381 and 383 µm). Moreover, goblet cells proportion in pigs fed 24% CP and 18% CP + NEAA diets were higher (P < 0.05) than that of 18% CP (53.2 and 53.4 to 45.3%). In the jejunum, pigs fed 18% CP + NEAA diet had reduced (P < 0.05) crypt depth than those fed 24% CP (161 and 141 µm), whereas pigs fed 18% CP presented intermediate results (144 µm). In the ileum, pigs fed the 24% CP diets presented a higher (P < 0.05) number of Peyer’s patches compared to 18% CP and 18% CP + NEAA (48 to 38 and 41 units).
Article Quarter: FY23 Q3
Role of amino acids and protein in health-challenged nursery pigs
The post-weaning period is a critical time in the pig’s life with both short- and long-term consequences for both productivity and health. Nutrition plays a vital role in this transition period and, as with swine production as a whole, the focus is largely on maximizing growth performance. However, feeding programs also need to account for immature and developing gastrointestinal and immune systems in the newly-weaned pig. In examining the impact of nutrition on gastrointestinal and immune health, it has become evident that protein and amino acids play a vital role. While protein and amino acids are needed in order to meet requirements for growth, excess protein can predispose pigs to post-weaning diarrhea, thought to be the result of fermentation of undigested protein and proliferation of enteric pathogens. In addition, the source of protein may also have a significant impact on performance and health of nursery pigs. Traditionally, amino acid requirements, and thus dietary inclusion, have been based on maximizing growth performance. It has become evident that the requirements of some amino acids may differ when based on development of the gastrointestinal tract and during times of immune stimulation, such as during disease challenge.
Growth performance in pigs fed a high soybean meal diet during heat stress
In the U.S. swine industry, feeding programs are focused on utilizing feed ingredients that are easily digestible and cost effective. With the predicted increases in soybean processing, pig producers may have increased availability of a cost-effective protein source in soybean meal (SBM). This expanded availability of SBM may result in feeding protein above the ostensible requirements, which would likely intensify the thermic effect of digestion, potentially increasing the pig’s susceptibility to heat stress (HS). Heat stress has damaging effects on feed intake and growth performance, costing the swine industry >$900 million annually. Therefore, the study objectives were to evaluate the effects of dietary crude protein diets (in the form of SBM) during HS on growth performance in growing pigs. Forty growing pigs (55 ± 5.6 kg) were allocated into six treatments: 1) thermoneutral (TN) ad libitum control diet (TN-Ctl; n = 6), 2) TN pair-fed (PF) control diet (PF-Ctl; n = 6), 3) HS ad libitum control diet (HS-Ctl; n = 8), 4) TN ad libitum high SBM diet (TN-SBM; n = 6), 5) TN PF high SBM diet (PF-SBM; n = 6), and 6) HS ad libitum high SBM diet (HS-SBM; n = 8). The control diet included 15% crude protein (CP) while the high SBM diet included 23% CP with excess amino acids. The study consisted of two periods: Period 1 (P1; 7 d) in which all pigs were housed in TN environments (26.7 ± 1.4°C) with ad libitum access to respective diets. Period 2 (P2; 21 d), HS groups were exposed to cyclical HS with daytime temperatures reaching 35°C and evening temperatures decreased to 29.4°C. During P2, PF groups were fed to respective HS-Ctl or HS-SBM equivalents in TN conditions. Pigs exposed to HS had an overall increase in rectal temperature and respiration rate (0.91°C and 45 bpm, respectively; P ≤ 0.01) and HS-SBM pigs had increased evening rectal temperature (± 0.13°C; P ≤ 0.01), relative to HS-Ctrl. Overall, HS decreased ADFI (19%; P ≤ 0.01), ADG (26%; P ≤ 0.01) and increased F:G (10%; P ≤ 0.01) irrespective of dietary CP levels. Loin muscle area (P = 0.19) and backfat (P = 0.98) were not different between the TN and HS pigs regardless of diet. Circulating blood urea nitrogen levels did not differ between HS and TN pigs (P = 0.68), but an increase was observed in pigs fed the SBM diet relative to the control diet (P ≤ 0.01).
Effect of protein source on piglet performance and dietary protein digestibility in regular nursery and Escherichia coli challenged conditions
Compared to conventional soybean meal (SBM), processed soy protein has been demonstrated to have higher nutrient digestibility, leading to better animal growth performance and gut health. The aim of the present study was to test hypothesis that Provisoy, a SBM product produced via hydrothermal mechanical treatment could improve weaning piglet growth performance via higher crude protein (CP) digestibility compared to SBM and this benefit would be greater in pigs under Escherichia coli (ETEC) challenged conditions. A total of 268 weaned pigs (initial body weight, BW = 6.82 ± 0.85 kg) were allotted to a split plot design and pigs were housed in either a regular nursery condition (5 pigs/pen, 10-11 pens/treatment) or an ETEC challenged condition (3 pigs/pen, 12 pens/treatment, 1 pig per pen was orally gavaged with 10 mL O149K91K88 on d5 post-weaning). All pigs were fed one of the following diets: SBM, Provisoy or HP300. A standard wheat-barley-SBM based nursery diet was used and test soy products were added to replace SBM in the treatment diets. All diets were formulated to be isocaloric and had similar standardized ileal digestible lysine level in a three-phase (38 days) nursery program. One pig per pen was euthanized for ileal digesta and fecal samples were collected on post-weaning day 13 and 14. Data were analyzed by general linear model in R. In summary, there was no interaction between challenge condition and dietary protein source on intake and gain throughout all three phases. A significant interaction in G:F between d0-7 post-weaning (P < 0.05) was observed. As expected, pigs performed better in regular conditions compared to challenged conditions (P < 0.05). Dietary protein source significantly affected ADG (P < 0.05) and BW (P < 0.01) on post-weaning d7 regardless of challenge condition, with pigs fed Provisoy exhibiting increased ADG and d7 BW vs the control but not different than HP300. Similar improvement in growth performance was observed during d7-12 post-weaning. However, the effect of protein source on piglet growth was no longer evident during the last phase of nursery. There was no interaction observed between challenge condition and protein source on CP apparent ileal digestibility (AID) or apparent total tract digestibility (ATTD). Dietary protein source affected CP ATTD (P < 0.01), with Provisoy treatment having the highest value compared to other treatments. Challenge conditions tended to decrease CP AID (P = 0.109).
Evaluation of dietary fiber in health challenged nursery pigs
Enteric pathogens often antagonize nursery pig health, growth performance, and scouring. Increased dietary fiber may alleviate bacterial pathogen burdens via improving intestinal health, fecal consistency, binding of pathogens, and improving early post-weaned growth performance. Therefore, our objective was to evaluate the effect of three dietary fiber sources on growth performance, digestibility, and fecal consistency in nursery pigs undergoing an F18 enterotoxigenic Escherichia coli (ETEC) challenge. The study was conducted with 541 newly weaned pigs (starting BW of 5.9 ± 1.25 kg) in a complete randomized design with four dietary treatments (n = 12 pens/treatment, 11-12 pigs/pen), fed over three phases. Phase 1 (day 0 – 14) and 2 (day 15 – 28) treatments included: 1) corn-soybean meal-based diet with no addition of fiber source (CON); 2) corn-soybean meal-based diet + 15 and 7.50% oat groats (phase 1 and 2, respectively) (Oats); 3) corn-soybean meal-based diet + 5% soyhulls (Soyhulls); and 4) corn-soybean meal-based diet + 5% wheat bran (Wheat Bran). All pens were fed a common Phase 3 (day 29 – 48) corn-soybean meal-based diet. At placement, 12 pigs were sacrificed for baseline evaluation and pigs were confirmed positive for K88 E. coli and Rotavirus A. On day 14 (dpi 0), all pigs were orally drenched with ~5 mL F18 ETEC inoculum suspended in Luria broth. On day 21 of the study (dpi 7), 1 pig/pen was euthanized to examine the effects of diet on intestinal health including histopathology assessment of attachment of E. coli, coccidia, villus atrophy, and colitis. Pig BW and pen feed disappearance were recorded weekly from day 0 – 28, and day 48 to calculate ADG, ADFI, and feed efficiency (G:F). Data were analyzed using PROC MIXED of SAS with pen as the experimental unit and the fixed effect of treatment. There were no differences in ADG, ADFI, or G:F in phase 1 or phase 2 when pigs were fed Oats, Soyhulls, or Wheat Bran when compared to CON (P > 0.05). Overall nursery ADG (0.43 vs. 0.41, 0.42, 0.40 kg/d, respectively), ADFI (0.67 vs. 0.67, 0.68, 0.64 kg/d, respectively), and G:F (0.55 vs. 0.55, 0.55, 0.55, respectively) were not different from CON when pigs were fed either Oat, Soyhulls, or Wheat Bran (P > 0.05). Pigs fed Oats had a decreased fecal nitrogen content compared to CON, Soyhulls, and Wheat Bran (P < 0.05) and no differences in dry matter, organic matter, or gross energy (P > 0.05). Although scouring was observed, fecal consistency scores did not differ between dietary treatments.
Effects of soy hulls and sugar beet pulp on growth performance of nursery pigs
An experiment was conducted to determine the interactive effects of soy hulls (SH) and sugar beet pulp (SBP) on growth performance of nursery pigs. A total of 2,448 mixed sex pigs (initial BW = 6.3 kg), placed in pens of 36 pigs each, were used in a 40-d trial. Treatments were arranged in a 2 × 3 factorial with two levels of SBP (0 or 5%) and 3 levels of SH (0, 3.75, or 7.5%) with 11 replicates per treatment. Corn and a fermented soybean meal product (ME-Pro, Prairie AquaTech, Brookings, SD) were replaced by the fiber sources to achieve the desired fiber concentration, whereas soybean meal inclusion rate was held constant across treatments. Diets were not balanced for net energy. Experimental diets were fed from d 0 to 18 and a common corn-soybean meal-based diet was fed from d 18 to 40. Pigs were weighed on d 0, 18, and 40 to calculate ADG, ADFI, and G:F. Data was analyzed with the MIXED procedure in SAS. From d 0 to 18, there was a SH × SBP interaction for ADG (P = 0.016) and ADFI (P = 0.023). Pigs fed diets with the highest inclusion of SH without SBP had increased ADG and ADFI; however, pigs fed diets containing SBP had improved performance up to 3.75% SH inclusion, and decreased ADG and ADFI with the highest SH inclusion. From d 18 to 40 and overall (d 0 to 40), there was an interaction (P ≤ 0.007) for G:F, where pigs fed diets containing 3.75% SH without SBP had improved G:F, while pigs fed diets with 3.75% SH containing SBP had worsened G:F.
Investigating the role of soybean meal and its innate bioactive compounds on nursery pig systemic health, inflammatory markers, and gastrointestinal physiology
Soybean meal (SBM) inclusion is reduced in young pig diets due to antinutritional factors that may negatively impact performance and gut function. However, when SBM is fed to grower pigs under disease or environmental stress, health may improve through modulation of immunity. Presently it is unknown if a parallel effect will be realized in nursery pigs. Therefore, the experimental objective was to examine the role of SBM and its bioactive compounds on nursery pig gastrointestinal physiology, systemic health, and inflammatory markers. Two replications of 18 barrows (8.12 ±0.80 kg BW; PIC800×Camborough), were randomly assigned to 1 of 6 dietary treatments: a high SBM positive control (SBMC; 28.6%), a negative control void of SBM (SP), but included soy protein isolate and concentrate to provide amino acids equivalent to SBM in SBMC; SP formulated to similar contribution and composition of isoflavones as SBMC (SP+ISO; 528 mg/kg of soy isoflavones); SP diet fortified with soybean lecithin and phytosterols at similar concentrations to SBMC (SP+LIP; 2.85 g/kg of functional lipids); SP formulated to an equivalent ratio of insoluble to soluble fiber as SBM in SBMC (SP+FIB; 30 g/kg of soy fiber); or SP diet fortified with lunasin-peptide at 3.81 g/kg (SP+LUN). Pigs were individually housed, and limit fed 2.5 times maintenance for a metabolism study consisting of a 6-d adaptation period, followed by 72-h of urine and fecal collections, and a 12-h lactulose:mannitol test. On d 11, whole blood and serum were collected prior to feeding, and at 2, 5, and 24 h post-feeding via jugular-venipuncture. Serum was analyzed for total antioxidant capacity (TAC) and malondialdehyde (MDA). Hematology was measured on whole blood. On d 12, pigs were necropsied for intestinal tissues collection. Data were analyzed as a linear mixed model with treatment as a fixed effect, replicate as a random effect, and initial BW as a covariate where appropriate. A dependent covariance structure was used for repeated measurements. Pigs fed either SBMC or SP+LIP had greater mean corpuscular volume and hematocrit % (P=0.027). Relative to the SP diet, pigs fed SP+LIP tended to have 11.4% greater hemoglobin concentrations (P=0.086). Circulating total white blood cells (WBC) were 21.2% and 22.6% lower in pigs fed SBMC and SP+ISO diet, respectively, relative to SP (P=0.002). Similarly, SBMC and SP+ISO had reduced neutrophil counts (P=0.043). Relative to SP, SBMC, SP+ISO, and SP+FIB tended to have increased systemic TAC (P=0.086). Pigs fed either SBMC or SPC+ISO had over a 2-fold increase in the TAC of the jejunum, relative to SP (P=0.039), but those fed SPC+FIB had increased TAC in the ileum and reduced MDA (P<0.05).
Use of specialty soy products as alternatives to poultry meal and spray-dried blood plasma in nursery pig diets
A total of 2,260 pigs (initially 6.7 ± 0.3 kg) were used to evaluate specialty soy protein sources as alternatives to poultry meal and spray-dried blood plasma on nursery pig performance. 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. Pigs were fed experimental diets during phase 1 (d 0 to 7) and phase 2 (d 7 to 21) followed by a common diet for an additional 21 d (d 21 to 42). 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) and a 2 × 2 factorial with a novel soy protein concentrate (AX3 Digest; Protekta; Plainfield, IN) or microbial enhanced soy protein (MEPro; Prairie Aquatech; Brookings, SD) replacing poultry meal or poultry meal and spray-dried blood plasma. Protein sources were added to the diet to maintain a similar level of soybean meal and balance for SID amino acids. Thus, soy protein sources were added to the diet at 6 and 13 (phase 1) or 10.75% (phase 2) to replace poultry meal or poultry meal and spray-dried blood plasma, respectively. Dietary treatment structure allowed the opportunity to compare each protein source to each other, soy protein sources as a replacement to poultry meal, and soy protein sources as a replacement to spray-dried blood plasma. During the experimental period (d 0 to 21), pigs fed novel soy protein concentrate had improved (P < 0.001) G:F with no differences (P > 0.10) in ADG or ADFI compared to pigs fed microbial enhanced soy protein. Pigs fed either soy protein as a replacement of poultry meal had increased (P < 0.001) ADG and ADFI compared to pigs fed the control diet. Additionally, pigs fed either soy protein source as a replacement of spray-dried blood plasma had improved (P = 0.044) G:F compared to pigs fed either soy protein without replacing spray-dried blood plasma, with no differences (P > 0.10) in ADG or ADFI.
Estimating the net energy requirement of piglets during the first three weeks post-weaning
Previous work has reported that piglets may be unable to increase feed intake to meet energy demands in low-energy diets, contrary to growing pigs. Indeed, poor feed intake in piglets occurs mainly during the first three weeks post-weaning. The approach, in this case, has been to increase the energy density of weaner diets to meet energy requirements even at lower intakes. Studies estimating the net energy (NE) requirement in piglets in the immediate post-weaning period are lacking. Hence the objective of the present study was to evaluate the dietary NE level required to optimize growth and feed efficiency in piglets during the first 21 d post-weaning. A total of 360 mixed-sex piglets (6.4 ± 0.24 kg) were housed with three pigs/pen and 24 pens/treatment (n=24 pens) and were assigned to 1 of 5 dietary treatments in a dose-response arrangement for 21-d. The experimental diets were formulated to contain graded dietary NE levels (2200, 2300, 2400, 2500, and 2600 kcal NE/kg). Diets were isonitrogenous and balanced for amino acids with a constant SID Lys/NE ratio of 1.25 across the treatments. The orthogonal polynomial contrast statement was used in a GLM model (PROC GLM, SAS studio) to determine the linear and quadratic effects of increasing dietary NE level on performance parameters. Results for the overall 21-d period indicated that, as dietary NE increased, average daily gain (ADG) increased linearly (P = 0.03). The average daily feed intake (ADFI) was not significantly (P = 0.157) affected by increasing dietary NE. The gain to feed (G:F) improved linearly as dietary NE increased (P = 0.008). Using the linear-breakpoint model (PROC NLIN), the NE estimated to maximize ADG at 305 g/day was 2475 kcal NE/kg (P = 0.008). Similarly, for maximum G:F of 0.86 g/g, the linear breakpoint model estimated the NE requirement at 2460 kcal/kg (P = 0.02). No breakpoint was estimated for ADFI, but the model tended (P = 0.08) to show a linear increase in ADFI as NE increased. In summary, the results of this study highlight that, during the first three weeks post-weaning, piglets’ feed intake may be more controlled by animal factors (gut capacity, etc.) and, to a lesser extent, energy concentration because feed intake was not affected by the dietary NE level in this study. Further, results show that ADG may be a more accurate measure of the impact of NE concentration than ADFI.
Individual precision feeding can greatly reduce global warming, eutrophication, and acidification environmental impacts
Nitrogen and phosphorus excretion are among the primary potential sources of environmental contamination in growing-finishing pig operations. Nutrient excretion can be reduced by feeding pigs with daily tailored diets to their estimated nutrient requirements using individual precision feeding (IPF) techniques. The environmental impact of moving from conventional group 3-phase-feeding (CON) to IPF systems in Québec, Canada, was evaluated in this study using life-cycle analysis. A cradle-to-farm gate life-cycle analysis was conducted using Simapro software (v. 8.0.3.14; PRE Consultants, Amersfoort, The Netherlands). The model included inputs and outputs of each sub-phase: raw materials/feedstuffs production, feed mill processing transport, animal rearing (maternity, weaning, and fattening units), and manure spreading in all livestock productions. All feed ingredients originated from Quebec (Montérégie region) and agricultural practices were simulated using real management data from an average farm in Quebec. Based on observed pig growth data, the CON and IPF systems were compared in the growing-finishing phase (Andretta et al., 2016). IPF diets were obtained by blending two feeds (i.e., A and B), while CON diets were formulated according to the ones used by the industry. The evaluated impact categories were global warming (GW), eutrophication (EU), and acidification (AC). The functional unit was 1 ton of feed at the feed mill gate, and 1 ton of pig live weight at the farm gate for finished pigs. A Monte Carlo analysis was performed to determine the uncertainty of the growth performance results. Feeding programs were compared with an analysis of variance. Corn was the ingredient with higher GW and AC impacts, therefore, diets with higher corn content were those with higher impacts in these categories. Feed B, which contained 83.2% of corn, resulted in impacts of 570 kg of CO2 eq., 8.21 kg SO2 eq. and 6,27 kg PO4 eq. Diets with higher EU impact were those with a higher percentage of soybean meal. Feed A contained 25.4% of this ingredient and impacted 554 kg of CO2 eq., 6,84 kg SO2 eq. and 7.05 kg PO4 eq. CON diets had environmental impacts between those of feeds A and B. Compared to CON, IPF decreased GW by 5.1%, AC by 14.2% and EU by 12.2%.
