Reduction In ADG Research Articles

Effect of chronic cyclic heat stress and supplemented inorganic and organic zinc source levels on grow-finish pig growth performance and estimated body composition.

Zinc (Zn) supplementation has proved to mitigate the effects of heat stress with varying effects evident with Zn source during acute heat events. However, the effects of Zn supplementation during long-term summer weather patterns have yet to be explored. Therefore, the objective of this study was to identify the effects of supplementation source and level of Zn to mitigate the negative effects of long-term, cyclic heat stress in finishing swine. Six hundred cross-bred pigs were housed under thermoneutral (TN) or cyclic heat (HS) conditions simulating summer heat with acute 3-d heat waves for a 70-d study. Thermoneutral conditions were 16.7 to 18.9 °C throughout the study. HS pigs were housed at the same temperature as TN from days 0 to 18, then 28 °C/24 °C for 12h/12h on days 18 to 21, followed by 30 °C/26.7 °C for 12h/12h on days 24 to 70, except during acute heat (32 to 33 °C/29 to 30 °C, 12h/12h) on days 21 to 24, 42 to 45, and 63 to 66. Treatments were arranged in a 2 × 6 factorial with main effects of environment (HS vs. TN) and dietary available Zn supplementation: (1) 50mg/kg zinc oxide (ZnO), (2) 130mg/kg ZnO, (3) 50mg/kg of organic Zn (Availa Zn), (4) 50mg/kg ZnO + 40mg/kg organic Zn, (5) 50mg/kg ZnO + 60mg/kg organic Zn, and (6) 50mg/kg ZnO + 80mg/kg organic Zn. Pigs (5 pigs/pen) were blocked by initial body weight (72.2kg) and randomly allotted to 1 of 12 temperature and diet treatment combinations across 10 replicates. Body weight and feed intake were determined at the beginning and end of each acute heat event. All pigs were ultrasonically scanned at the 10th rib (TR) to predict loin muscle area (LMA), backfat (BF), and percent lean. Data were analyzed by the MIXED procedure in SAS with pen as the experimental unit. At day 63, HS pigs were lighter (P < 0.05), had lower overall average daily gain (ADG; P < 0.05) and average daily feed intake (P < 0.05). A diet-by-environment interaction was observed for overall ADG (P < 0.05) with diet 5 HS pigs having a 3.9% reduction in ADG whereas diet 6 had 14.4% reduction in ADG, while under TN temperatures diet 6 had the greatest overall ADG of all treatments. Other diets were intermediate in their ADG under both HS and TN conditions. Pigs under HS had less BF at the TR (P < 0.05) and a smaller LMA (P < 0.05), and a greater calculated percent lean (P < 0.05). Our results indicate that a blend of supplemental Zn sources at 50/60mg/kg may mitigate the reduction in growth performance due to HS. While not directly contrasted, the NRC requirement of 50mg/kg Zn may be too low to optimize finishing pig growth performance under both TN and HS conditions.

Nutritional guide to feeding wheat and wheat co-products to swine: a review.

Inclusion of wheat grain can offer feeding opportunities in swine diets because of its high starch, crude protein (CP), amino acid (AA), and phosphorus (P) content. High concentrations of starch within wheat grain makes it a good energy source for swine. Mean energy content of wheat was 4,900 and 3,785 kcal/kg dry matter (DM) for digestible energy and metabolizable energy, respectively. CP concentration can vary based on the class of wheat which include hard red winter, hard red spring, soft red winter, hard white, soft white, and durum. The average CP of all wheat data collected in this review was 12.6% with a range of 8.5% to 17.6%. The AA concentration of wheat increases with increasing CP with the mean Lys content of 0.38% with a standardized ileal digestibility (SID) of 76.8%. As CP of wheat increases, the SID of AA in wheat also increases. Mean P of wheat was 0.27% and median P was 0.30%. Off-quality wheat is often associated with sprouts, low-test weight, or mycotoxin-contamination. Sprouted and low-test weight wheat are physical abnormalities associated with decreased starch within wheat kernel that leads to reductions in energy. The assumed energy value of wheat grain may need to be reduced by up to 10% when the proportion of sprouted to non-sprouted wheat is up to 40% whereas above 40%, wheat's energy may need to be reduced by 15% to 20%. Low-test weight wheat appears to not influence pig performance unless it falls below 644kg/m3 and then energy value should be decreased by 5% compared to normal wheat. Deoxynivalenol (DON) contamination is most common with wheat grain. When content is above the guidance level of 1mg/kg of DON in the complete diet, each 1mg/kg increase in a DON-contaminated wheat-based diet will result in a 11% and 6% reduction in ADG and ADFI for nursery pigs, and a 2.7% and 2.6% reduction in ADG and ADFI, in finishing pigs, respectively. Wheat co-products are produced from the flour milling industry. Wheat co-products include wheat bran middlings, millrun, shorts, and red dog. Wheat co-products can be used in swine diets, but application may change because of differences in the final diet energy concentration due to changes in the starch and fiber levels of each wheat co-product. However, feeding wheat co-products are being evaluated to improve digestive health. Overall, wheat and wheat co-products can be fed in all stages of production if energy and other nutrient characteristics are considered.

250 The Impact of Increasing Levels of Dried Distillers Grains and Solubles on Finishing Pig Performance

Abstract Due to ethanol plants continuing to be more efficient extracting corn oil out of dried distillers grains and solubles (DDGS), it is necessary to understand how pigs are utilizing the energy in diets with increasing levels of current DDGS. A total of 1,120 finishing pigs (DNA 600 x 241, initially 17.5 kg) were used in a 120-day experiment to evaluate the effects of DDGS on growth performance from approximately 8 to 25 weeks of age. Dietary treatments consisted of a corn and soybean meal-based diet with either 0, 10, 20, 30, or 40% DDGS. Pigs were fed a seven-phase finishing diet program to meet their nutritional requirements. Dietary energy was allowed to fluctuate with changing levels of DDGS while maintaining a constant SID lysine to calorie ratio. Pens of pigs were randomly allotted to 1 of the 5 treatments, with 32 pigs per pen and 7 replicates per treatment. Sex was equally represented in each pen. Pigs were harvested (average final BW of 127 kg) at a commercial facility. Data were modeled in R (R Core Team, 2020) to test for both linearity and non-linear responses to DDGS levels in the diet. Models included DDGS treatment and trial start weight and pen was the experiment unit. Traits analyzed included average daily gain (ADG, kg/d), Gain to Feed (G:F), average daily feed intake (ADFI, kg/d), hot carcass weight (kg) and carcass yield (%). All traits were found to have linear trends with increasing DDGS inclusion levels (Linear: P ≤ 0.02; Quadratic: P ≥ 0.29). Overall, there was a reduction in ADG as DDGS inclusion increased from 1.00 (± 0.01) with 0% DDGS to 0.96 (± 0.01) kg/day for 40% DDGS (P = 0.04). There was a decrease in gain to feed ratio (0.39 to 0.35) with increasing DDGS inclusion (P &amp;lt; 0.001). Hot carcass weight decreased with increased inclusion of DDGS from 97.25 to 93.39 kg (P = 0.001), while carcass yield was not significantly different across DDGS inclusion levels ranging from 75.3% to 74.7% for 0% and 40% DDGS inclusion (P = 0.2), respectively. These data indicate that increasing levels of DDGS reduce ADG, feed efficiency, and carcass weight.

192 Effect of Dietary Anhydrous Calcium Chloride in Early and Late Finishing on Pig Performance and Body Composition

Abstract Understanding how to control pig growth is critical during market disruptions, including foreign animal disease and harvest facility shutdowns. In times of severe market disruptions, feeding acidogenic salts such as anhydrous calcium chloride to suppress appetite is an effective way to manage pig growth. Therefore, the aim of this study was to understand the impact of feeding calcium chloride during early and late growth stages on grow-finish growth and body composition of pigs. Barrows and gilts (n = 240; 52 ± 6.9 kg BW) were allotted by sex across 60 pens and to one of three treatments fed in 3 diet phases (Phase 1, d 1-28; Phase 2 d 28-56; Phase 3 d 57-87). Treatment included: 1) Control corn-soy diets in phases 1-3, 2) 3% CaCl2 intervention in phase 1, control diet fed in phases 2 and 3 (IP1), and 3) Control diet fed in phases 1 and 2, and 3% CaCl2 intervention in phase 3 (IP3). All diets were formulated to meet or exceed amino acid and energy requirements and pigs were fed ad libitum. Pig BW were recorded at the start and end of each phase, and pen feed disappearance was recorded to calculate pen ADG, ADFI, and G: F. Loin eye area and fat depth were measured using real-time ultrasound at the end of phases 1 and 3. Data were analyzed with pen as the experimental unit and treatment, gender, and their interaction as fixed effects. No noteworthy gender by diet interactions were demonstrated and only the diet treatment, overall performance, and ultrasound trait means are reported (Table 1). Compared with the Control and IP3, IP1 reduced ADFI and ADG by 42% and 60%, respectively, in phase 1 (P&amp;lt; 0.05). Feed efficiency, loin eye area, and fat depth were also reduced in the IP1 compared with the Control and IP3 pigs in phase 1 (P&amp;lt; 0.05). In phase 2, the IP1 pigs did not have a significant difference in feed intake and their ADG increased by 22% compared with the Control and IP3 pigs (P&amp;lt; 0.05) and therefore were more feed efficient. Implementation of CaCl2 in phase 3, the IP3 pigs reduced ADFI, ADG, and G: F compared with the control and IP1. Further, phase 3 loin eye area and fat depth were 13% and 17% less, respectively, in the IP3 pigs compared with the control. Overall, the IP3 treatment had the most severe reductions in ADG, ADFI, and feed efficiency (P&amp;lt; 0.05). Early intervention (IP1) also attenuated overall G: F, ADFI, and ADG compared with the Control (P&amp;lt; 0.05). These results demonstrate the efficacy of calcium chloride in attenuating pig feed intake and growth performance during early and late finishing.

208 Effect of SID LYS Level with Constant Non-Essential Amino Acids

Abstract Many investigations on the effect of low protein diets reduce crude protein (CP) and have a constant standardized ileal digestible (SID) LYS resulting in reductions in ADG, ADFI, and gain:feed is some cases. This experiment was conducted to determine the impact of maintaining constant non-essential amino acids and changing SID LYS and other essential amino acids. For the experiment, 288 pigs (~22 d of age, 6.61 ± 0.95 kg, 8 replicates/treatment, 6 pigs/pen) were stratified by body (BW) and randomly allotted to one of 6 treatments in a randomized complete block design. Non-essential amino acids were fixed in all diets and synthetic amino acids were added to increase SID LYS from 1.15% to 1.4% while maintaining constant ratios of MET+CYS, THR, TRP, VAL, and ILE to LYS. Diets were corn, wheat, barley, and soy based with 1.1% corn starch in the least SID LYS diet. Synthetic amino acids were added to the diet at the expense of corn starch to maintain non-essential amino acid levels. The CP ranged from 17.8% when SID LYS was 1.15% and 18.6% when SID LYS was 1.4%. Experimental diets were fed for 21 d. Body weight, feed disappearance, visual fecal scores, and visual piglet scores were measured. Visual fecal scores (1 = normal to 4 = watery) and visual pig appearance scores (1 = pale and hairy to 4 = normal color and well-rounded muscle) were assessed on ordered likert scales to determine the probabilities of observing a more normal stool quality and a worse visual appearance, respectively. Performance data were analyzed as a general linear model. Stool quality and visual appearance were analyzed as a generalized linear mixed model. Contrasts were used to test linear and quadratic effects of dietary SID LYS. Results of the experiment are presented in Table 1. Increasing SID LYS with constant non-essential amino acids did not affect ADG or BW. The ADFI was linearly decreased (P &amp;lt; 0.1) and gain:feed was linearly increased (P &amp;lt; 0.0001) with increasing SID LYS (Table 1). Stool quality was not affected. Visual appearance of the pigs was quadratically affected (P &amp;lt; 0.05) by changing SID LYS. Pigs that had consumed diets with the lowest or highest SID LYS had the best visual appearance (lowest probability). The results of the current experiment differ suggest SID LYS may regulate feed intake and nutrient efficiency, but BW gain is not affected when non-essential amino acids are held constant. This differs from cases where CP is reduced, which results are decreased growth in many cases.

138 Effects of Wheat Middlings Inclusion Rate on Growth Performance of Nursery Pigs

Abstract An experiment was conducted to determine the effects of wheat middlings inclusion rate on growth performance of nursery pigs. A total of 1,750 pigs (initial BW = 6.0 kg), placed in pens with 35 pigs each, were used in a 39-d trial. There were 5 treatments consisting of 0, 5, 10, 15, or 20% wheat middlings. Corn and a fermented soybean meal product (ME-Pro, Prairie AquaTech, Brookings, SD) were replaced by wheat middlings to achieve the desired levels, whereas soybean meal inclusion rate was constant across treatments. Diets were not balanced for net energy. The experimental diets were fed from d 0 to 18 and a common corn-soybean meal-based diet was fed from d 18 to 39. There were 10 replicates per treatment. Pigs were weighed on d 0, 18, and 39 to calculate ADG, ADFI, and G:F. Data were analyzed with SAS MIXED procedure. From d 0 to 18, there was a linear (P = 0.041) reduction in ADG with increasing levels of wheat middlings; however, the differences were small (ranging from maximum 288 to minimum 275 g/d). This response was driven by a tendency (P = 0.096) for a linear ADFI response and a quadratic (P = 0.023) G:F response. From d 18 to 39, there was a linear (P = 0.016) G:F response, where pigs previously fed high levels of wheat middlings had improved G:F. Overall (d 0 to 39), there was no evidence (P &amp;gt; 0.10) for differences on growth performance. In conclusion, pigs fed high levels of wheat middlings had slightly decreased performance from d 0 to 18, but no evidence for differences were observed in the overall nursery period.

Evaluation of the combined effects of different dose levels of Zinc oxide with probiotics complex supplementation on the growth performance, nutrient digestibility, faecal microbiota, noxious gas emissions and faecal score of weaning pigs.

This study was conducted to assess the effects of different dose levels of zinc oxide (ZnO) combined with probiotics complex supplementation on the growth, performance, nutrient digestibility, faecal lactobacillusandEnterobacteriacounts, noxious gas emissions and faecal score of weaned piglets. A total of 180 crossbred weaning pigs ([Yorkshire×Landrace]×Duroc; 6.61±1.29kg [mean±SE]; 28days old) were used in a 42-day trial. All pigs were randomly allotted to 1 of 4 treatment diets based on initial BW and sex (9 replicate pens/treatment; 2 gilts and 3 barrows/pen). Dietary treatment groups were as follows: CON, basal diet +ZnO 3,000ppm; BZS, basal diet +ZnO 2,100ppm +0.1% SynerZymeF10; BZS1, basal diet +ZnO 1,200ppm +0.1% SynerZymeF10; BZS2, basal diet +ZnO 300ppm +0.1% SynerZymeF10. During the phase 3, decreasing the ZnO concentration led to a linear reduction in ADG (p=0.044), and the ADG was lower (p<0.05) in BZS2 compared with CON treatment during the whole experimental period. The effects of dietary ZnO with probiotics complex were not detected (p>0.05) on nutrient digestibility, Lactobacillus and E.coli counts, faecal gas emissions and faecal scores. In conclusion, the diet supplementation of ZnO (1,200ppm) with probiotics complex has been shown to have comparable efficacy to ZnO (3,000ppm) diet on growth performance, nutrient digestibility, faecal microbiota, noxious gas emissions and faecal score of weaning pigs.

36 Evaluation and mitigation of the effects of in utero heat stress on pig performance following weaning and transport

Abstract In utero heat stress (IUHS) negatively affects swine productivity and is a growing concern for the swine industry. The study objective was to evaluate and mitigate the negative effects of IUHS on pig performance following weaning and transport. Based on previous research, we hypothesized that IUHS pigs would have reduced performance relative to in utero thermoneutral (IUTN) pigs due to greater maintenance costs and supplementing a nutrient-dense (ND) diet would improve IUHS pig performance to similar levels as IUTN pigs fed a common (C) diet. Therefore, 24 bred gilts were assigned to either thermoneutral (TN; n = 12; 17.5 ± 2.1°C) or heat stress (HS; n = 12; cyclical 27°C to 37°C) conditions for the first half of gestation (d1 to 58) and then TN conditions for the remainder of gestation. At weaning (16.2 ± 0.4 d), pigs (N = 160; 4.78 ± 0.15 kg BW) were transported (loading + transport + unloading) for approximately 12h. Pigs were then blocked into pens (n = 4 pigs/pen) by in utero and dietary treatments which were fed for 14 d (Period-1): IUTN-C (n = 10 pens), IUTN-ND (n = 10 pens), IUHS-C (n = 10 pens), IUHS-ND (n = 10 pens). Following Period-1, all pigs were fed the C diet from d15 to 35 post-weaning and transport (Period-2). Production measures were taken on d 0, 7, 14, 21, 28, and 35 post-weaning and transport to calculate ADG, ADFI, and G:F. During Period-1, ADG was reduced overall (P = 0.03, 10.6%) for IUHS pigs compared to IUTN pigs. Pigs fed ND diets had reduced ADFI during Period-1 (P = 0.02, 8.8%) relative to C fed pigs, regardless of in utero treatment. During Period-2, ADFI was increased (P = 0.03, 4.7%) in ND versus C pigs, regardless of in utero treatment. In summary, increasing the nutrient density of the diet did not rescue the lost productivity of IUHS pigs as indicated by an overall reduction in ADG.

158 Effect of fumonisin-contaminated corn on growth performance of 9- to 28-kg nursery pigs

Abstract A total of 350 pigs (241×600; DNA, Columbus, NE; initially 8.9 kg) were used in a 28-d study to determine the effect of fumonisin-contaminated corn on growth performance of nursery pigs. Dietary treatments consisted of fumonisin-contaminated corn blended with low fumonisin corn to provide analyzed toxin (FB1 + FB2) levels in the final diet of 7.2, 14.7, 21.9, 32.7, and 35.1 ppm. There were 5 pigs per pen and 14 pens per treatment. Pens were assigned to treatments in a randomized complete block design with initial weight as the blocking factor. Data were analyzed using lme package in R program with pen as the experimental unit. From d 0 to 28, increasing fumonisin decreased (linear, P&amp;lt; 0.05) ADG, ADFI, G:F, and final BW. Although responses tested linear, the greatest reduction in ADG and G:F was observed in pigs fed 32.7 and 35.1 ppm of fumonisin. Increasing fumonisin increased serum sphinganine to sphingosine (Sa:So) ratios (linear, P&amp;lt; 0.001) on day 14 and 28. Serum Sa:So ratio appears to be a useful biomarker indicating fumonisin intoxication. These results suggest that for 9- to 28-kg nursery pigs, diets containing 32 ppm of fumonisin or greater decreased growth performance and increased serum Sa:So ratio. Further research is warranted to determine the effects of fumonisin concentrations between 22 and 32 ppm.

74 Stocker management and impacts on health and subsequent feedlot performance

Abstract The stocker segment of the beef industry provides significant enterprise services. The stocker industry provides a shock absorber to absorb the bulk of the cattle not ready for finishing in the numbers glut in the fall and helps provide a year around supply of feeder cattle. Other benefits include adding size to small and medium frame cattle to allow them to finish at acceptable weights, grouping cattle from small herds into semiload lots, and improved health and resilience to the stressors of changing diets, management, and environment. Health during receiving to the finishing phase has been shown to impact finishing performance and carcass quality, so the effects of stocker management can have serious implications on long-term economics of the feedlot enterprise and consumer acceptance of beef products. Ratliff et al. (2014) compiled data from Arkansas receiving and stocker grazing experiments and found that calves coming into the receiving unit as bulls were more likely to experience 2nd and 3rd pulls for bovine respiratory disease and had lower gains during grazing than calves coming in as steers. Records from research trials conducted in Mississippi and Arkansas found a 6 to 14% reduction in ADG for calves that had been treated for BRD once vs two times or more, respectively. There is much less data that considers the health outcomes of calves received as light weight stocker cattle and how this impacts subsequent performance during finishing. Timing of application of growth promoting technologies during the stocker phase has been shown to affect response to implants during finishing and carcass quality, but little data is available regarding stocker cattle health and finishing performance. More research is needed to ascertain what determines the quality of the health intervention outcomes for individual animals and the subsequent implications of health in the stocker phase

Evaluation of dietary electrolyte balance on nursery pig performance.

Increasing dietary electrolyte balance (dEB) has been reported to linearly improve pig growth performance up to approximately 200 to 250 mEq/kg. However, recent data indicate that increasing dietary dEB reduced growth performance of nursery pigs. To attempt to solve this discrepancy, a total of 2,880 weanling pigs (327 × 1,050; PIC, Hendersonville, TN; 5.2 kg initial BW) were used to determine the effects of increasing dEB on nursery pig performance. Pens of pigs were blocked by BW and gender on arrival. Within block, pens were randomly assigned to one of four dietary treatments. There were 30 pigs per pen (60 pigs per double-sided feeder) and 12 replications (feeder) per treatment. Dietary treatments were fed in two phases. The phase 1 diet was based on corn–soybean meal, contained dried distillers grains with soblubles (DDGS), spray-dried whey, and specialty protein sources, and was fed from days 0 to 8. The phase 2 (days 8 to 21) diets contained corn, soybean meal, and DDGS with reduced amounts of specialty protein sources. Dietary electrolyte balance was determined using the following equation: dEB = [(Na × 434.98) + (K × 255.74) − (Cl × 282.06)] mEq/kg. The dEB of the four phase 1 diets were 84, 137, 190, and 243 mEq/kg, and dEB of the four phase 2 diets were 29, 86, 143, and 199 mEq/kg. After feeding experimental diets for 21 day, a common, commercial corn–soybean meal diet was fed to all pigs from days 21 to 35 and contained a dEB of 257 mEq/kg. During days 0 to 8, increasing dEB increased (quadratic, P < 0.05) ADG, ADFI, and G:F. From days 8 to 21, increasing dEB improved ADG (quadratic, P = 0.022) and ADFI (linear, P = 0.001), resulting in an improvement (quadratic, P = 0.001) in G:F. Overall (days 0 to 21), increasing dEB increased (linear, P < 0.05) ADG, ADFI, and improved (quadratic, P < 0.001) G:F. When a common diet was fed to all pigs from days 21 to 35, there was a linear reduction in ADG and G:F with increasing dietary dEB, but no effect of ADFI. For the overall nursery period (days 0 to 35), increasing dEB from days 0 to 21 increased (linear, P < 0.001) ADG and final BW, which was the result of increased (quadratic, P < 0.05) G:F and marginally greater (linear, P = 0.077) ADFI. In conclusion, increasing dietary dEB up to 243 and 199 mEq/kg (in phases 1 and 2, respectively) in nursery diets improved growth performance of weanling pigs.

Investigation of carryover effect of prior fibre consumption on growth, serum and tissue metabolic markers in Ossabaw pigs fed a high-fat diet.

Carryover effect of prior fibre consumption on metabolic markers was investigated. Treatments were arranged in 2×2 factorial with 2 fibre sources, 4% inulin or cellulose (Solka-Floc®) and fat levels (5 or 15%) for the low-fat diet (LFD) and high-fat diet (HFD) respectively. Pigs were fed the two fibre diets for the first 56d (nursery phase), and thereafter fed either the LFD or HFD containing no added fibre source from d56 to 140 (growing phase). Pigs on the HFD were heavier (p=.05) than those on LF (64.61 vs. 68.38kg), regardless of prior fibre type consumed. Pigs that were fed cellulose during the nursery and later fed the HFD had the highest ADG (p<.05). Feeding the HFD resulted in higher back fat (BF) (13.41 and 18.18±0.12mm for LFD and HFD, respectively; p<.01). The HFD resulted in higher (p<.01) insulin (0.014 and 0.016±0.001mg/L for LF and HF respectively) and glucose (100.89 and 125.03±4.39mg/dl for LF and HF respectively) concentrations in the serum. Inulin increased (p≤.02) jejunal expression of SREBP-1c and CL-4, but reduced (p<.05) TNFɑ and IL-6 expression in the ileum. Alpha-diversity was significantly different (p<.05) between the inulin and cellulose fed pigs at the end of the nursery and finishing phases. Therefore, inulin feeding before a HFD may lead to reduction in ADG and inflammatory markers in the small intestine of pigs, and thus prevent future metabolic disorders.

Impact of Mycoplasma hyopneumoniae and Lawsonia intracellularis on the performance of pigs divergently selected for feed efficiency.

Feed efficiency (FE) is a valuable trait, yet how genetic selection for enhanced FE affects other processes such as response to disease is unknown. Disease from endemic respiratory and enteric pathogens such as Mycoplasma hyopneumoniae (Mh) and Lawsonia intracellularis (LI) are common in swine production. Therefore, the aim of this study was to examine if pigs selected for high vs. low FE based on residual feed intake (RFI) respond differently to a dual respiratory and enteric challenge. Pigs selected for low RFI (LRFI, high FE) are considered more FE compared to their high RFI (HRFI, low FE) selected counterparts. Using a 2 × 2 factorial design, 25 littermate pairs from the HRFI and 25 littermate pairs from the LRFI line (barrows, 50 ± 7 kg BW) were selected, with one pig from each pair assigned to individual pens in either the challenge or the nonchallenge (control) rooms (n = 25 barrows/line/challenge). On days post inoculation (dpi) 0, the challenged pigs were inoculated with LI and Mh (MhLI). Feed intake, BW, fecal swabs, and serum samples were collected and recorded weekly for 42 d. On dpi -2 and 47, 14 littermate pairs (n = 7 barrows/line/challenge) were utilized for initial and final body composition scans using dual-energy X-ray absorptiometry to calculate longitudinal whole body tissue accretion rates for lean, protein, fat, and bone mineral content. Serum antibody levels and fecal shedding of LI were used to confirm infection. Control pigs remained negative by all measures during the 6-wk trial and MhLI inoculated pigs were confirmed positive via serological antibody responses by dpi 14 for LI and Mh. There were no interactions between RFI line and challenge status for any overall performance parameter (P > 0.05). The 6-wk MhLI challenge resulted in a 17% reduction in ADG, a 12% reduction in ADFI, and a 7% reduction in G:F vs. Controls (P < 0.05). In addition, compared to the Control pigs, MhLI challenge reduced lean, protein, and lipid accretion rates by 16% (P < 0.05). Genetic selection for high FE resulted in decreased ADFI and increased G:F (P < 0.01), but did not impact ADG or tissue accretion vs. low FE pigs. Collectively, these results demonstrate that a dual enteric and respiratory pathogen challenge reduced ADG, ADFI, G:F, and tissue accretion in growing pigs. Further, there was no evidence that selection for enhanced FE based on RFI index affects response to disease.

Ground Juniperus pinchotii and urea in supplements fed to Rambouillet ewe lambs Part 2: Ewe lamb rumen microbial communities.

This study evaluated effects of ground redberry juniper () and urea in dried distillers grains with solubles-based supplements fed to Rambouillet ewe lambs ( = 48) on rumen physiological parameters and bacterial diversity. In a randomized study (40 d), individually-penned lambs were fed ground sorghum-sudangrass hay and of 1 of 8 supplements (6 lambs/treatment; 533 g/d; as-fed basis) in a 4 × 2 factorial design with 4 concentrations of ground juniper (15%, 30%, 45%, or 60% of DM) and 2 levels of urea (1% or 3% of DM). Increasing juniper resulted in minor changes in microbial β-diversity (PERMANOVA, pseudo F = 1.33, = 0.04); however, concentrations of urea did not show detectable broad-scale differences at phylum, family, or genus levels according to ANOSIM ( > 0.05), AMOVA ( > 0.10), and PERMANOVA ( > 0.05). Linear discriminant analysis indicated some genera were specific to certain dietary treatments ( < 0.05), though none of these genera were present in high abundance; high concentrations of juniper were associated with and , low concentrations of urea were associated with , and high concentrations of urea were associated with and . were decreased by juniper and urea. , , and increased with juniper and were positively correlated (Spearman's, < 0.05) with each other but not to rumen factors, suggesting a symbiotic interaction. Overall, there was not a juniper × urea interaction for total VFA, VFA by concentration or percent total, pH, or ammonia ( 0.29). When considering only percent inclusion of juniper, ruminal pH and proportion of acetic acid linearly increased ( < 0.001) and percentage of butyric acid linearly decreased ( = 0.009). Lamb ADG and G:F were positively correlated with (Spearman's, < 0.05) and negatively correlated with Synergistaceae, the BS5 group, and Lentisphaerae. Firmicutes were negatively correlated with serum urea nitrogen, ammonia, total VFA, total acetate, and total propionate. Overall, modest differences in bacterial diversity among treatments occurred in the abundance or evenness of several OTUs, but there was not a significant difference in OTU richness. As diversity was largely unchanged, the reduction in ADG and lower-end BW was likely due t* reduced DMI rather than a reduction in microbial fermentative ability.

Digestibility and performance of steers fed varying inclusions of corn silage and modified distillers grains with solubles to partially replace corn in finishing diets.

Two finishing and 1 digestibility experiment evaluated the partial substitution of corn with corn silage and corn modified distillers grains with solubles (MDGS). Steers were used in Exp. 1 (n = 295; 467 ± 52 kg) and Exp. 2 (n = 225; BW = 348 ± 27 kg) in a 2 × 2 + 1 factorial arrangement of treatments with factors including corn silage (15 or 45%) and MDGS (20 or 40%) plus a control diet consisting of 5% cornstalks and 40% MDGS. In Exp. 1, there were tendencies for a corn silage × MDGS interaction for ADG, final BW, and G:F (P ≤ 0.08). In the overall F-test for G:F, there were no differences between the control treatment and 15:20, 15:40, or 45:40 (P ≥ 0.15), however, steers fed the control treatment had increased G:F compared to steers fed 45:20 treatment diets (P = 0.03). In Exp. 2, there were no corn silage × MDGS interactions (P ≥ 0.12). As corn silage increased in the diet, ADG, final BW, and G:F decreased (P ≤ 0.01). As MDGS increased from 20 to 40%, ADG and G:F tended to improve (P ≤ 0.07). In the overall F-test, the control was not different for G:F from 15:20, 45:20, or 45:40 (P ≥ 0.15), but had a 4.8% poorer G:F compared to 15:40 (P < 0.01). In Exp. 3, ruminally fistulated steers (n = 6) were used in a 5 × 6 Latin rectangle design and fed 15 or 45% corn silage with 20 or 40% MDGS as a 2 × 2 factorial. An additional diet consisting of 95% corn silage and 5% supplement was fed. There were no corn silage × MDGS interactions for nutrient intake, total tract digestibility, ruminal pH measurements, acetate: propionate ratio (A:P), or in-situ disappearance data (P ≥ 0.31) for the 2 × 2 factorial. As corn silage increased in the diet, DMI, NDF intake, ruminal pH, A:P, in-situ NDF disappearance of corn bran, and DM disappearance of corn increased (P ≤ 0.09) with decreases in DM and OM digestibility (P ≤ 0.03). As MDGS increased in the diet, there was an increase in NDF intake, total volatile fatty acid concentration, and NDF disappearance of corn bran (P ≤ 0.03) with no differences for any other tested variables (P ≥ 0.13). In general, increasing corn silage in place of corn in finishing diets containing MDGS results in a modest reduction in ADG and G:F with increases in ruminal pH.

Peroxidized lipids reduce growth performance of poultry and swine: A meta-analysis

Animal performance is affected by feeding peroxidized lipids. Nevertheless, inaccuracies and limitations of common lipid peroxidation analyses are associated with inconsistent results regarding animals consuming diets with peroxidized lipids. A comprehensive meta-analysis was conducted to determine the effects of feeding dietary peroxidized lipids on growth performance and oxidative status in poultry and swine. A total of 29 publications with 42 poultry and 23 swine observations were analyzed. Concentration of dietary thiobarbituric acid reactive substances (TBARS) and peroxide value (PV), along with ADG, ADFI, G:F, and serum or plasma concentrations of vitamin E and TBARS were obtained from publications when reported. The relative impact of feeding peroxidized lipids was calculated as a percentage of ADG, ADFI, and G:F relative to responses from feeding isocaloric diets containing unperoxidized lipids. Data were analyzed for outliers, general distribution, and correlations among variables. Overall, feeding peroxidized lipids to both species resulted in a 5% reduction in ADG, a 3% reduction in ADFI, and G:F was reduced by 2% compared with feeding unperoxidized lipids. The difference in the average magnitude of reduction in ADG, compared with less average magnitude of reduction in ADFI, suggests that factors other than caloric intake (i.e. oxidative stress) contribute to reduced ADG when feeding peroxidized lipids. Both species fed peroxidized lipids had reduced serum or plasma vitamin E content (52%) and increased TBARS concentration (120%) relative to animals fed unperoxidized lipids, suggesting that feeding peroxidized lipids contributes to increased oxidative stress. Dietary PV was negatively correlated with ADG (r=− 0.81, P<0.01) for poultry, whereas for swine, dietary TBARS was negatively correlated with ADG (r=− 0.58, P=0.04), but there were large prediction errors for poultry (MSE=0.87) and swine (MSE=12.79). In conclusion, these results suggest that feeding peroxidized lipids reduce growth performance of poultry and swine, but the magnitude of reduction varies among experiments due to differences in fatty acid profiles among types of lipid sources, time and temperature of peroxidation conditions, and relative growth responses among studies. More accurate peroxidation measurement methods need to be developed to accurately estimate the negative impacts of feeding peroxidized lipids on animal growth performance.

Effects of potential detoxifying agents on growth performance and deoxynivalenol (DON) urinary balance characteristics of nursery pigs fed DON-contaminated wheat.

Two experiments were conducted to evaluate potential detoxifying agents on growth of nursery pigs fed deoxynivalenol (DON)-contaminated diets. Naturally DON-contaminated wheat (6 mg/kg) was used to achieve desired DON levels. In a 21-d study, 238 pigs (13.4 ± 1.8 kg BW) were used in a completely randomized design with a 2 × 2 + 1 factorial arrangement. Diets were: 1) Positive control (PC; < 0.5 mg/kg DON), 2) PC + 1.0% Product V (Nutriquest LLC, Mason City, IA), 3) Negative control (NC; 4.0 mg/kg DON), 4) NC + 1.0% Product V, and 5) NC + 1.0% sodium metabisulfite (SMB; Samirian Chemicals, Campbell, CA). There were 6 or 7 replicate pens/treatment and 7 pigs/pen. Analyzed DON was decreased by 92% when pelleted with SMB, but otherwise matched formulated levels. Overall, a DON × Product V interaction was observed for ADG ( 0.05) with a tendency for an interaction for ADFI ( 0.10). As anticipated, DON reduced ( 0.001) ADG and ADFI, but the interaction was driven by even poorer growth when Product V was added to NC diets. Pigs fed NC diets had 10% poorer G:F ( 0.001) than PC-fed pigs. Reductions in ADG due to DON were most distinct (50%) during the initial period. Adding SMB to NC diets improved ( 0.01) ADG, ADFI, and G:F, and improved ( 0.02) ADG and G:F compared to the PC diet. A urinary balance study was conducted using diets 3 to 5 from Exp. 1 to evaluate Product V and SMB on DON urinary metabolism. A 10 d adaptation was followed by a 7 d collection using 24 barrows in a randomized complete block design. Pigs fed NC + SMB diet had greater urinary DON output ( 0.05) than pigs fed NC + Product V, with NC pigs intermediate. Daily DON excretion was lowest ( 0.05) in the NC + SMB pigs. However, degradation of DON-sulfonate back to the parent DON molecule was observed as pigs fed NC + SMB excreted more DON than they consumed (164% of daily DON intake), greater ( 0.001) than pigs fed the NC (59%) or NC + Product V (48%). Overall, Product V did not alleviate DON effects on growth nor did it reduce DON absorption and excretion. However, hydrothermally processing DON-contaminated diets with 1.0% SMB restored ADFI and improved G:F. Even so, the urinary balance experiment revealed that some of the converted DON-sulfonate can degrade back to DON under physiological conditions. While further research is needed to discern the stability of the DON-sulfonate, SMB appears promising to restore performance in pelleted DON-contaminated diets.

Nursery pig growth performance and tissue accretion modulation due to porcine epidemic diarrhea virus or porcine deltacoronavirus challenge.

Porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) are both members of the family Coronaviridae which induce clinical signs of diarrhea, dehydration, and in some circumstances, mortality. Most research has been focused on isolation, genome sequencing, pathogenicity, and virulence of these viruses, but there is little information on long-term growth performance and tissue accretion of pigs inoculated with PEDV or PDCoV. Therefore, our objective was to determine the effect of PEDV or PDCoV infection on growth performance and tissue accretion over 42 d following inoculation. A total of 75 Choice Genetics Large White Pureline barrows and gilts (BW = 10.81 ± 0.81 kg) at approximately 2 wk post-wean and naïve for PEDV and PDCoV were selected. Pigs were allotted based on BW and sex, stratified across 3 treatments with 8 pens per treatment. Treatments were: 1) Control (n = 8); 2) PEDV inoculated (n = 8); and 3) PDCoV inoculated (n = 8). On day post inoculation (dpi) 2, 5, 7, and 14 pigs were euthanized for tissue collection and analyses from these tissues are discussed elsewhere. Pen feed intake and BW were recorded on dpi 2, 5, 7, and weekly thereafter until dpi 42. On 1 designated pig per pen, initial and final body composition was determined using dual-energy X-ray absorptiometry (DXA) and tissue accretion rates were calculated over 6 wk test period. Peak PEDV infection was noted at 3 dpi compared with 4 dpi for PDCoV pigs as determined by fecal swab quantitative real-time PCR (RT-PCR). Control pigs remained negative for PEDV and PDCoV throughout the experiment. Overall, Control and PDCoV pigs did not differ in ADG, ADFI or G:F (P > 0.05). Compared to Control and PDCoV pigs, the overall 42 d ADFI was reduced in the challenged PEDV pigs (P < 0.05) by 19 and 27%, respectively. PEDV did not significantly reduce the overall ADG or G:F compared with Control and PDCoV pigs; however, the biggest reduction in ADG and ADFI for PEDV pigs was within 14 dpi compared to the Control pigs (P < 0.05). Whole body tissue accretion was altered due to PED, with fat, lean, protein, and bone mineral accretion reductions by 24, 20, 21, and 42%, respectively (P < 0.05) compared with Control pigs. Overall, nursery pig performance was greatly impacted by PEDV challenge. Surprisingly, the PDCoV challenge did not negatively influence nursery pig performance. This study provides further insight into the longitudinal impact swine enteric coronaviruses have on growing pigs.

Short-term effect of supplemental yeast extract without or with feed enzymes on growth performance, immune status and gut structure of weaned pigs challenged with Escherichia coli lipopolysaccharide.

BackgroundThis study investigated the response of piglets receiving a yeast extract without or with a multi-enzyme mixture compared with an antimicrobial growth promoter (AGP) on performance, immune status and gut structure after an E. coli lipopolysaccharide (LPS) challenge. Thirty-six pigs were allotted to six treatments including: a non-challenged control (NCC); LPS-challenged control (CC); CC + AGP; CC + yeast extract; CC + enzymes; and CC + enzymes + yeast extract. On d 7, pigs were bled and thereafter injected with LPS or sterile saline. Blood samples were collected at 6, 48, and 96 h post-challenge. After 96 h post-challenge, pigs were euthanized to obtain duodenal, jejunal and ileal samples.ResultsOverall (d 1 to 11), compared with CC pigs, AGP attenuated the LPS-induced reduction in ADG (P = 0.004), ADFI (P = 0.03) and gain/feed ratio (P = 0.01). At 6 h post-challenge, AGP pigs had lower plasma urea N (PUN; P = 0.02) and serum TNF- α concentration (P = 0.07), and higher platelet count (P = 0.04) and serum IL-10 concentration (P = 0.02) than CC pigs. At 48 h post-challenge, AGP pigs had lower PUN (P = 0.02) than CC pigs, whereas enzymes + yeast extract interacted non-additively (P = 0.001) to reduce PUN. At 96 h post-challenge, AGP pigs had lower PUN (P = 0.02) and higher duodenal (P = 0.03), jejunal (P = 0.01) and ileal (P = 0.07) villus height than CC pigs. In addition, enzymes + yeast extract interacted additively and non-additively to reduce ileal IFN-γ (P < 0.0001) and IL-10 (P = 0.012) expression, respectively. Generally, no differences (P > 0.10) were observed between AGP and enzymes + yeast extract pigs on other measured parameters except for the downregulation of ileal IFN-γ (P < 0.0001) and TNF-α (P = 0.003) in enzymes + yeast extract pigs at 96 h post-challenge.ConclusionsThe LPS challenged piglets receiving enzymes + yeast extract showed beneficial responses in gut structure and immunity commensurate with those receiving antibiotics, though the latter had better overall growth performance.

The progression of deoxynivalenol-induced growth suppression in nursery pigs and the potential of an algae-modified montmorillonite clay to mitigate these effects.

Two experiments were conducted to characterize the progression of deoxynivalenol (DON)-induced growth suppression and to investigate algae-modified montmorillonite clay (AMMC) as a means to alleviate the effects of DON in nursery pigs. In both experiments, naturally DON-contaminated wheat was used to produce diets with desired DON levels. In Exp. 1, 280 barrows and gilts (10.0 ± 0.2 kg BW) were used in a 28-d experiment arranged in a 2 × 2 + 1 factorial design with 8 replicates per treatment. The 5 treatments consisted of 2 positive control (PC) diets with DON below detection limits and with or without 0 or 0.50% AMMC and 3 negative control (NC) diets with 5 mg/kg of DON and containing 0, 0.25, or 0.50% AMMC. No DON × AMMC interactions were observed. Overall, pigs fed DON had decreased ( < 0.001) ADG and final BW regardless of AMMC addition. Feeding DON-contaminated diets elicited the most severe depression ( < 0.001) in ADFI and G:F from d 0 to 3, remaining poorer overall ( < 0.01) but lessening in severity as exposure time increased. Pigs fed DON diets had greater ( < 0.05) within pen BW variation (CV) on d 28. Although the addition of 0.50% AMMC to diets restored ( < 0.05) ADFI from d 14 to 21 to levels similar to the PC, no other differences were observed for AMMC inclusion. In Exp. 2, 360 barrows (11.4 ± 0.2 kg BW) were used in a 21-d experiment with 9 dietary treatments arranged in a 3 × 3 factorial design with DON and AMMC inclusion as main effects. There were 8 replicate pens per treatment. Treatments consisted of 3 PC diets without DON, 3 low-DON (1.5 mg/kg DON) NC diets, and 3 high-DON (3 mg/kg DON) NC diets with 0, 0.17, or 0.50% AMMC incorporated at each DON level. No DON × AMMC interactions were observed. As DON level increased, ADG and final BW decreased (quadratic, < 0.05), driven by decreased (quadratic, < 0.01) ADFI and poorer (quadratic; < 0.05) G:F. At both 1.5 and 3 mg/kg DON, reductions in ADG were most marked from d 0 to 7 (15 to 22% lower) and were least distinct from d 14 to 21 (5 to 6% lower). Incorporating AMMC at increasing levels had no effect on ADG, ADFI, G:F, or final BW. Overall, these experiments reinforce DON effects on feed intake but also indicate that the effects of DON on G:F may be more severe than previously thought. Furthermore, some pigs appear to develop tolerance to DON, as effects on ADFI and G:F lessen over time. However, the addition of AMMC did not offset the deleterious effects of DON.