Growing-finishing Pigs Research Articles

Optimising the hygiene of a liquid feeding system to improve the quality of liquid feed for pigs

Poor feeding system hygiene may contribute to uncontrolled spontaneous fermentation in liquid pig feed and its associated undesirable effects. This study aimed to determine the effects of an intensive sanitisation programme in a grow-finisher liquid feeding system by monitoring microbiological and physico-chemical parameters of liquid feed and microbial colonisation of the feeding system surfaces. The sanitisation programme involved a combination of physical and chemical cleaning between batches of grow-finisher pigs, combined with nightly rinsing of the system with an organic acid blend. Improved hygiene of the internal surfaces of the mixing tank and feed pipeline, particularly until week 5 post-cleaning, was evidenced by reduced counts of lactic acid bacteria, total aerobes, Enterobacteriaceae, yeasts and moulds and decreased adenosine triphosphate concentrations. Enterobacteriaceae and moulds remained undetectable on pipeline surfaces for 10 weeks. Scanning electron microscopy of the feed pipelines confirmed these findings. Conversely, the impact on liquid feed microbiology was minimal and short-lived. However, acetic acid, ethanol and biogenic amine concentrations decreased in the feed post-cleaning and no gross energy losses were observed. Therefore, by controlling surface microbial communities on liquid feeding systems via implementation of the sanitisation programme developed in the current study, on-farm liquid feed quality should be improved.

First molecular detection of Brachyspira hampsonii on pig farms in Poland.

Nowadays, the three strongly beta-haemolytic spirochaetes, Brachyspira hyodysenteriae, Brachyspira suanatina and Brachyspira hampsonii are thought to be causative agents of swine dysentery, an economically devastating disease of grow-finish pigs characterised by severe mucohaemorrhagic diarrhoea. B. hyodysenteriae has been reported in most leading swine-producing regions. B. suanatina and B. hampsonii have been successfully recovered from faecal samples collected in a few countries only. Thepresent study was performed in March 2023 on faecal samples originating from nine Polish finisher farms with 6,000 to 18,000 animals in a location. Samples were obtained from 40 diarrhoeic finishers. Nucleic acid extracted from the samples was analysed using multiplex PCR for Brachyspira spp. From a total of nine sample populations examined in our study, the genetic material of B. hampsonii was identified in two. To the best of our knowledge, this is the first report on molecular detection of B. hampsonii on pig farms outside North America, Belgium and Germany. Our research highlights the need for increased focus directed on laboratory testing strategies, the lack of which may perplex swine practitioners and severely hinder a definite diagnosis.

Effects of single and complex probiotics in growing-finishing pigs and swine compost.

This study was conducted to supplement single and complex probiotics to investigate the effect on growing-finishing pigs and compost. In experiment 1, the 64 crossbred ([Landrace × Yorkshire] × Duroc) pigs with an initial body weight of 18.75 ± 0.33 kg and a birth of 63 days were assigned to a completely randomized four treatment groups based on the initial body weight (4 pigs in a pen with 4 replicate pens for each treatment). For 13 weeks, the dietary treatments were provided: 1) Control (CON; basal diet), 2) T1 (CON + 0.2% Bacillus subtilis), 3) T2 (CON + 0.2% Saccharomyces cerevisiae), 4) T3 (CON + 0.2% Bacillus subtilis + 0.2% Saccharomyces cerevisiae). In experiment 2, the pig manure was obtained from Chungbuk National University (Cheongju, Korea) swine farm. For 12 weeks, the supplementary treatments were provided: 1) CON, non-additive compost; 2) T1, spray Bacillus subtilis 10 g per 3.306 m2; 3) T2, spray Bacillus subtilis 40 g per 3.306 m2; 4) T3, spray Saccharomyces cerevisiae 10 g per 3.306 m2; 5) T4: spray Saccharomyces cerevisiae 40 g per 3.306 m2; 6) T5, spray Bacillus subtilis 5 g + Saccharomyces cerevisiae 5 g per 3.306 m2; 7) T6, spray Saccharomyces subtilis 20 g + S. cerevisiae 20 g per 3.306 m2 and there were 6 replicates each treatment. In experiment 1, During the overall experimental period, T3 showed significantly improved (p < 0.05) feed conversion ratio and average daily gain compared to other groups. In average maturity score, T3 showed significantly higher (p < 0.05) than other groups. Supplementing complex probiotics group improved (p < 0.05) H2S emissions and fecal microflora compared to the non-supplementing group. In experiment 2, additive probiotics groups had no effect (p > 0.05) on moisture content than the non-additive group at 9 and 12 weeks. T6 showed a significantly improved (p < 0.05) average maturity score at all periods and ammonia emissions at 1 week and 4 weeks compared to other groups. In summary, supplementation complex probiotics induced positive effects on both pigs and compost.

A New Biosynthetic 6-Phytase Added at 500 Phytase Unit/kg Diet Improves Growth Performance, Bone Mineralization, and Nutrient Digestibility and Retention in Weaned Piglets and Growing-Finishing Pigs.

Two experiments were performed to evaluate the effect of a biosynthetic 6-phytase added at 500 phytase unit (FTU)/kg diet on growth performance, bone mineralization, and nutrient digestibility and retention in weaned piglets and growing-finishing pigs. Experiments were performed on 90 weaned male and female piglets with an average initial body weight (BW) at 7.7 ± 0.73 kg, 26 days of age) and 300 male and female growing pigs (initial BW: 21.0 ± 3.44 kg) for 43 and 98 days in experiments 1 and 2, respectively. In each experiment, the animals were assigned to one of three treatments according to a randomized complete block design. The treatments consisted of a positive-control (PC) diet formulated to meet nutrient requirements; a negative-control (NC) diet reduced similarly in calcium (Ca) and digestible P by 0.15 and 0.12% points in phases 1 and 2, respectively, in piglets and by 0.14, 0.11, and 0.10% points, respectively, in phases 1, 2, and 3 in growing-finishing pigs, compared with PC diet; and a NC diet supplemented with the new 6-phytase at 500 FTU/kg diet (PHY). The dietary P and Ca depletion reduced (p < 0.05) the final BW (-11.9%; -7.8%,), average daily gain (ADG, -17.8%; -10.1%), average daily feed intake (ADFI, -9.9%; -6.0%), gain-to-feed (G:F) ratio (-8.9%; -4.6%), and apparent total tract digestibility (ATTD) of P (-7.7% points; -6.7% points) in nursery piglets and growing pigs, respectively. It also decreased (p < 0.001) P and Ca retention by 6.1 and 9.4% points, respectively, in nursery pigs and ash, P, and Ca contents in metacarpal bones by 18.4, 18.4, and 16.8%, respectively, in growing pigs. Compared to animals fed the NC diet, phytase supplementation improved (p < 0.001) the final BW (+7.7%; +11.3%), ADG (+12.5%; +15.0%), G:F ratio (+8.4%; +5.8%), ATTD of Ca (+10.8% points; +7.2% points), and ATTD of P (+18.7% points; +16.6% points) in weaned piglets and growing pigs, respectively. In addition, phytase also increased (p < 0.001) P and Ca retention by 6.1 and 9.4% points, respectively, in nursery pigs and ash, P, and Ca contents in metacarpal bones by 17.7, 15.0, and 15.2%, respectively, in growing pigs. The final BW, ADG, G:F ratio, and bone traits in animals fed the NC diet supplemented with phytase were comparable to animals fed the PC diet. This finding indicates the ability of this novel biosynthetic phytase to restore performance and bone mineralization by improving the availability of P and Ca in piglets and growing pigs fed P- and Ca-deficient diets.

Improving Efficiency: Automatic Intelligent Weighing System as a Replacement for Manual Pig Weighing.

To verify the accuracy of AIWS, we weighed 106 pen growing-finishing pigs' weights using both the manual and AIWS methods, respectively. Accuracy was evaluated based on the values of MAE, MAPE, and RMSE. In the growth experiment, manual weighing was conducted every two weeks and AIWS predicted weight data was recorded daily, followed by fitting the growth curves. The results showed that MAE, MAPE, and RMSE values for 60 to 120 kg pigs were 3.48 kg, 3.71%, and 4.43 kg, respectively. The correlation coefficient r between the AIWS and manual method was 0.9410, and R2 was 0.8854. The two were extremely significant correlations (p < 0.001). In growth curve fitting, the AIWS method has lower AIC and BIC values than the manual method. The Logistic model by AIWS was the best-fit model. The age and body weight at the inflection point of the best-fit model were 164.46 d and 93.45 kg, respectively. The maximum growth rate was 831.66 g/d. In summary, AIWS can accurately predict pigs' body weights in actual production and has a better fitting effect on the growth curves of growing-finishing pigs. This study suggested that it was feasible for AIWS to replace manual weighing to measure the weight of 50 to 120 kg live pigs in large-scale farming.

Using poultry by-product meal to replace soybean meal in grower -finisher pig diets

This study investigated the effect of replacing soybean meal (SBM) with poultry by-product meal (PBM) in grower-finisher diets on pig feeding, growth performance, carcass yield and meat quality. The replacement levels were increased from no PBM (PBM0) to 37 g/kg PBM (PBM37), 85 g/kg PBM (PM85) and 111 g/kg PBM (PBM111). All diets met or exceeded nutrient requirements for pigs between 20 – 100 kg live weight (NRC, 2012). Sixty-four entire males (PIC 337 x PIC Camborough 42), at an average live weight (LW) of 27.60 ± 2.48 kg (mean ±SD) were blocked by LW and randomly assigned to 8 pens, with each diet replicated across 2 pens. Pigs had ad libitum access to diets via electronic feeders until they reached approximately 100 kg LW, at which time they were slaughtered. Results showed no significant effect of replacing SBM with PBM on pig feeding behavior parameters and the majority of pig growth performance, carcass yield, and meat quality traits, with the exception of higher feed conversion ratio (FCR) in pigs fed the PBM37 diet. Loin muscles from the group fed the PBM111 diet had significantly lower ultimate pH and a greater cooking loss than the other treatments (P < 0.05). Loin muscles from pigs fed high levels of PBM (PBM85 and PBM111) had greater ash content than those fed the PBM37 and control diets (P = 0.001). Overall, the present research indicated that PBM could be a viable primary protein source in diets for growing-finishing pigs, as it did not appear to have any adverse effects on pig feeding behavior, growth performance and meat quality. In addition, PBM is potentially a good source of calcium and phosphorus for growing–finishing pigs. However, due to the variation in quality and composition of available PBM, it is essential to measure nutritional composition before including PBM in diets for growing-finishing pigs.

Exploring individual responses to welfare issues in growing-finishing pig feeding behaviour

The feeding behaviour of individual growing-finishing pigs can be continuously monitored using sensors such as electronic feeding stations (EFSs), and this could be further used to monitor pig welfare. To make accurate conclusions about individual pig welfare, however, it is important to know whether deviations in feeding behaviour in response to welfare issues are shown only on average or by each individual pig. Therefore, this study aimed (1) to quantify the individual variation in feeding behaviour changes in response to a range of welfare issues, and (2) to explain this individual variation by quantifying the responses to welfare issues for specific subgroups of pigs. We monitored four rounds of 110 growing-finishing pigs each (3–4 months per round). We collected feeding behaviour data using IVOG® EFSs and identified health issues and heat stress using climate sensors and twice-weekly health observations. For each pig, a generalised additive model was fitted, which modelled feeding behaviour through time and estimated the effect of each welfare issue that the pig had suffered from. The range of these effect estimates was compared between pigs to study the individual variation in responses. Subsequently, pigs were repeatedly grouped using physical and feeding characteristics, and, with meta–subset analysis, it was determined for each group whether a deviation in response to the welfare issue (i.e. their combined effect estimates) was present. We found that the range in effect estimates was very large, approaching normal distributions for most combinations of welfare issues and feeding variables. This indicates that most pigs did not show feeding behaviour deviations during the welfare issue, while those that did could show both increases and reductions. One exception was heat stress, for which almost all pigs showed reductions in their feed intake, feeding duration and feeding frequency. When looking at subgroups of pigs, it was seen that especially for lameness and tail damage pigs with certain physical characteristics or feeding strategies did consistently deviate on some feeding components during welfare issues (e.g. only relatively heavier pigs reduced their feeding frequency during lameness). In conclusion, while detection of individual pigs suffering from heat stress using feeding variables should be feasible, detection of (mild) health issues would be difficult due to pigs responding differently, if at all, to a given health issue. For some pigs with specific physical or behavioural characteristics, nevertheless, detection of some health issues, such as lameness or tail damage, may be possible.

First Report of Porcine Parvovirus 2 (PPV2) in Pigs from Colombia Associated with Porcine Reproductive Failure (PRF) and Porcine Respiratory Disease Complex (PRDC)

Pigs are affected by various parvoviruses (PPVs); eight have been reported to date (PPV1–PPV8). Porcine parvovirus 1 is considered a primary agent of porcine reproductive failure (PRF), while it is unknown whether other PPVs impact porcine health. Recently, the presence of PPV2 has been confirmed in the lung, either as a single agent or in the form of coinfection with other respiratory; therefore, it has been proposed as a potential participant in the porcine respiratory disease complex (PRDC). In the present study, the presence of PPV2 alone and coinfection with other viruses (PCV2, PCV3, and PRRSV) was evaluated in lung samples obtained from pigs with respiratory signs (respiratory group: RG) (n = 146) and stillborn lungs (stillborn group: SG) (n = 19) from 82 farms in the five regions with the highest swine production in Colombia. The overall PPV2 prevalence was 37.6% (62/165), with the highest proportion mainly detected in grow-finisher pigs (62.5%), while its herd prevalence was 51.2% (42/82). The most prevalent virus was PRRSV in both groups, while PPV2 alone was found only in the RG group. The most common dual coinfection in the RG and SG was PCV2/PRRSV (17.8% and 10.5%), while the most frequent coinfections involving PPV2 in the RG were PPV2/PCV2 (7.5%) and PPV2/PRRSV (4%) and PPV2/PCV2 (5.3%) in the SG. The most common triple coinfection was PPV2/PCV2/PRRSV at 15% in the RG and 21% in the SG, while quadruple coinfection PVV2/PCV2/PCV3/PRRSV was detected only in the RG (5.5%). Histopathological evaluation of 21 PPV2-positive lungs showed variable degrees of histiocytic or lymphohistiocytic interstitial pneumonia (9%) in the RG, while no significant changes were observed in SG; in addition, neutrophilic bronchopneumonia was observed in 73.7% if cases evaluated. In situ hybridization-RNAScope® confirmed the presence of PPV2 within pulmonary lesions in 2/19 RG pigs, while no in situ detection was observed in the SG pigs. The phylogenetic evaluation of seven PPV2 sequences detected in Colombia was compared with another 102 reported sequences, indicating that the Colombian strains are located in clade 2. Our results confirm the presence of PPV2 in pigs with PRDC alone and pigs coinfected with PCV2, PCV3, and PRRSV. Likewise, its presence alone or in coinfection in stillbirths suggests that PPV2 is also involved in PRF.

Evaluation of dietary selenium sources and levels on growth performance, carcass characteristics, selenium concentrations, and blood parameters of growing-finishing pigs

Evaluation of dietary selenium sources and levels on growth performance, carcass characteristics, selenium concentrations, and blood parameters of growing-finishing pigs

Effects of dietary capsaicin supplementation on growth performance, blood profile and carcass and meat quality of finishing pigs.

This study was conducted to determine the effects of capsaicin (CAP) on productive performance, blood profile, intestinal morphology, carcass and meat quality of growing-finishing pigs. Two experimental diets were offered to 36 crossbred barrows: basal diet (0% CAP) and basal diet with CAP at 0.02%. Each experimental group consisted of 18 pigs, with six replications (three each). Supplementation of CAP at 0.02% decreased average daily feed intake (ADFI; p = 0.003) and feed cost/gain (FCG; p = 0.056), increased return on investment (ROI; p = 0.052) and increased gain:feed ratio (p = 0.037) during the growing period. There was no effect of CAP on the growth rate. The blood urea nitrogen (BUN) and nitrogen (N) levels in faeces tended to decrease (p = 0.093 and p = 0.087), whereas the basophil level increased with CAP supplementation (p = 0.029). In addition, dietary CAP supplementation decreased crypt depth (p = 0.022) and tended to increase the villus height/crypt depth ratio in the segment of the jejunum (p = 0.084). Backfat (BF) thickness (p = 0.047) was reduced by supplementing CAP. Whereas the protein content increased with CAP supplementation (p = 0.021). Using CAP in the diet of growing pigs increased the pH at 6 h post-mortem (p = 0.046) and tended to increase the springiness value (p = 0.078) of the meat. In terms of meat color, CAP supplementation increased the yellowness (p = 0.029). Supplemental CAP improves gut morphology and blood profiles, consequently promoting productive performance as well as carcass and meat quality.

126 A nutritional solution based on calcidiol (25-OH-D3, HyD) and triterpenoid affects muscle protein synthesis pathways in grower-finisher pigs

Abstract To boost profitability in pig production, it is important to achieve increased lean growth rates and maximize efficiency, especially in grower-finisher pigs where feed intakes are high. Molecular research, especially the study of gene expression, is a proven tool for understanding the precise mechanisms behind muscle tissue growth, including a recent focus on pathways such as the mammalian target of rapamycin (mTOR). In the current work, gene expression analyses were used to study the mode of action of the combination of calcidiol (25-OH-D3, HyD) and triterpenoid, which has shown significant growth and efficiency improvements in grower-finisher pigs (McCormack et al., 2024). Three experimental diets were evaluated for 7 wk; Positive control: 0.7% total Ca, 0.36% total P, vit D3 at 1500IU/kg feed (PC), negative control: PC diet + 30% reduced Ca and 10% reduced P (NC), and NC diet with 1,500IU D3 in calcidiol form (25-OH-D3, HyD) and triterpenoid (NC+). At 19 wk of age, 16 animals per treatment were sacrificed and tissue samples were taken from the longissimus muscle and preserved in RNA later solution. The RNA was extracted, quality control checked, and mRNA sequenced using the Illumina platform with 150 base pair paired-end sequencing and 30M read depth. The sequenced data were aligned to the Sus scrofa reference genome (Sscrofa11.1) using Kallisto. Data were normalized and analyzed for differentially expressed genes (DEGs) between treatments using DeSeq2. Genes were assigned to biological pathways using Biofractal’s customisation of the Reactome pathway database. For statistical analysis, RNA integrity number and treatment were included in the model. In the PC compared with the NC, there were 71 DEGs using a false discovery rate (FDR) of &amp;lt; 0.10. Altered pathways included the inhibition of cellular stress pathways and increased cell turnover in the muscle of PC compared with NC pigs. In the NC+ compared with the NC, there were 155 DEGs (FDR &amp;lt; 0.10). The most significantly upregulated gene in the NC+ treatment was adenylate cyclase (FDR &amp;lt; 0.001), an upstream regulator of several pathways related to energy metabolism and muscle protein synthesis. This mechanism was confirmed in the pathway analysis, which found that the NC+ treatment activated PKA-mediated phosphorylation of CREB, a pathway that inhibits muscle atrophy. Furthermore, the NC+ treatment activated several pathways related to muscle growth, including the mammalian target of rapamycin complex 1 (mTORC1). In this study the addition of calcidiol (25-OH-D3, HyD) and triterpenoid to the diet was found to specifically affect molecular pathways in the muscle of grower-finisher pigs involved in both the inhibition of muscle breakdown as well as activating muscle growth.

PSIII-20 Impact of EnduraPig on Performance of PRRSV-Negative growing-finishing pigs

Abstract A total of 479 weaned pigs [PIC Camborough × PIC 337; initial body weight (BW) = 26.8 kg; Porcine reproductive and respiratory syndrome virus, PRRSV-negative] were used to evaluate the effects of EnduraPig (PMI Additives), a patent-pending feed additive that has been designed to support health, performance, and immune function of pigs, on growth performance of growing-finishing pigs. Pigs were blocked by initial BW and gender and assigned to 48 pens, which were allotted to one of 4 dietary treatments (12 pens/treatment, 9-10 pigs/pen), including T1) Control, T2) EnduraPig 0.1% (EP low), T3) EnduraPig 0.2% (EP medium), and T4) EnduraPig 0.3% (EP high). The EnduraPig inclusion levels were reduced by one-half when pigs reached approximately 70 kg BW (d 42). A five-phase feeding program was used with all diets formulated on a corn-DDGS-soybean meal basis to meet the nutrient requirements of growing-finishing pigs. Analysis of variance for growth measures was performed using the MIXED Procedure of SAS (SAS 9.4), and polynomial contrasts were used to evaluate linear, quadratic, and cubic effects of the EP levels. Significant differences were declared at P ≤ 0.05 and trends at P ≤ 0.10. During d 0-72, feeding EnduraPig tended to improve average daily gain (ADG) (0.96, 0.97, 1.00, and 0.97 kg, respectively; cubic, P = 0.06) with the greatest ADG observed in EP medium. During d 72 to market, feeding EnduraPig increased ADG (1.13, 1.14, 1.18, and 1.17 kg, respectively; linear, P = 0.02), average daily feed intake (ADFI; 3.48, 3.42, 3.55, and 3.49, respectively; cubic, P = 0.02) and feed:gain (3.08, 3.00, 3.01, and 2.98, respectively; linear, P = 0.10). Overall (d 0-market), feeding EnduraPig enhanced ADG (1.02, 1.02, 1.05, and 1.03 kg, respectively; linear, quadratic, and cubic, P = 0.04, 0.09, 0.01), with the greatest ADG observed in EP medium resulting in a 4.0 kg greater market BW compared with the control (128.9, 129.2, 132.9, and 130.5, respectively; linear and cubic, P &amp;lt; 0.05). In addition, feeding EnduraPig numerically improved feed:gain (2.51, 2.48, 2.48, and 2.48, respectively; linear, P = 0.14). With respect to BW variation, feeding EnduraPig reduced the standard deviation in market BW (10.65, 8.06, 8.86, and 9.54 kg, respectively; quadratic, P &amp;lt; 0.05), with the greatest reduction from EP low and EP medium (by 24 and 17%, respectively) compared with the control. In summary, data from this study indicate that feeding EnduraPig at 0.2% from 27 kg to 70 kg BW and 0.1% from 70 to market improves growth performance and reduces BW variation of PRRSV-negative growing-finishing pigs.

PSVI-18 Low and high feed efficiency grower-finisher pigs fed three different levels of dietary crude protein showed no immediate difference in blood metabolomics profile

Abstract Improving feed efficiency (FE) of grower-finisher pigs is of great importance considering its impact on production economy, nutrient excretions as well as carbon-footprint. The biological background describing variation in FE between pen mates, is difficult to establish as feed intake (FI) and FE are not estimated on an individual level. In this study advanced feeding stations were used to estimate FI and further calculate feed conversion ratio (FCR) on individual level. The study aimed to investigate the possible difference in the blood metabolic profile between low and high FE grower-finisher pigs fed three different levels of dietary crude protein (CP). The study included 60 newly weaned gilts divided in two series, housed as 10 pigs/pen. The 30 pigs per series were distributed between three pens (10 pigs/pen) and were balanced by body weight and litter. Throughout the entire weaner period all pigs had ad libitum access to the same diet. Pigs were redistributed among the grower-finisher pens to balance FCR levels between dietary treatments (CP levels) and to reduce any carry over effect from the weaner to the grower-finisher pens. From 30-115 kg body weight (BW), pigs were fed either a low (L; 14.8% CP), standard (15.2% CP) or high (H; 15.8% CP) CP diet equal in energy, where BW, average weekly gain (AWG), and FCR were determined on weekly basis, while FI was estimated on daily basis. Three low FE (20% least) and three high FE (20% greatest) pigs were selected based on the final 4 wk of growth within station and CP level. On the final day of the experimental period all low-FE and high-FE pigs within each dietary treatment were euthanized and blood plasma was sampled and subjected to a nontargeted LC-MS metabolomics analysis. Growth performance and metabolite data were, respectively, analyzed in R and MetaboAnalyst 5.0 with FE and CP as fixed effects. High-FE and H-CP pigs continuously displayed numerically greater BW, while AWG and FCR were, respectively, numerically greater, and less in L-CP than H-CP group during last 2 wk of the experimental period. Principal Component Analysis (PCA) showed no grouping (P &amp;gt; 0.05) of metabolites and no specific pattern of the metabolic profile from either the two FE categories or the three dietary CP levels. Furthermore, no correlation (P &amp;gt;0.05) of metabolites to any other observation was found, and only little variation, measured by distance to model showing deviation of each pig to overall model, was observed. In conclusion, at first glance the metabolomics profile did not appear to present any specific pattern between low and high feed efficiency grower-finisher pigs or between pigs exposed to different levels of dietary CP in the grower finisher period.

PSVI-19 No apparent association between the microbiome in the distal part of the small intestine and feed efficiency in grower-finisher pigs fed three different levels of dietary crude protein

Abstract Improving feed efficiency (FE) of grower-finisher pigs is important considering its production, environmental and climate impact. The biological background describing variation in FE between pen mates, is difficult to establish as feed intake (FI) and FE is not estimated on an individual level. In this study advanced feeding stations were used to estimate FI and further calculate feed conversion ratio (FCR) on individual level. The study aimed to investigate the possible association between FCR and microbiome (alpha and beta diversity; observed features and Shannon index, and Bray-Curtis dissimilarity and Jaccard Distance) in the distal part of the small intestine (SI) in grower-finisher pigs fed three different levels of dietary crude protein (CP). The study included 60 newly weaned gilts divided in two series, housed as 10 pigs/pen. The 30 pigs per series were distributed between three pens (10 pigs/pen) and were balanced by body weight (BW) and litter with ad libitum access to the same diet. Pigs were redistributed among the grower-finisher pens to balance FCR levels between dietary treatments (CP levels) and to reduce any carry over effect from the weaner to the grower-finisher pens. From 30-115 kg BW, pigs were fed either a low (L; 14.8% CP), standard (Std; 15.2% CP) or high (H; 15.8% CP) CP diet equal in energy, where BW, average weekly gain (AWG), and FCR were determined on weekly basis, while FI was estimated on daily basis. Three low FE (20% least) and three high FE (20% greatest) pigs were selected based on the final 4 wk of growth within station and CP level. All low-FE and high-FE pigs within each dietary treatment were euthanized around 115 kg BW and content and mucosa scrabe from the distal part of the SI was sampled and subjected to 16S rRNA gene amplicon sequencing. Data were analyzed in R using a generalized linear mixed-effects model with FE, CP, and their interaction as explanatory variables, start BW of weaner and grower phase as covariables, and series as random effect. High-FE and H-CP pigs continuously displayed numerically greater BW, while AWG and FCR were, respectively, numerically greater, and less in L-CP than H-CP group during last 2 wk of the experimental period. While FE and CP individually had no significant impact [Pr(&amp;gt; Chisq] &amp;gt; 0.05), their interaction could be important in explaining the variation (Chisq = 6.42, Df = 2, Pr(&amp;gt;Chisq) = 0.04) as expressed by observed features. But a pairwise comparison with a Benjamini–Hochberg correction showed no difference between groups. Concerning the Shannon index, no significance was found between groups, and no difference with respect to beta diversity was observed. In conclusion, the microbiome as expressed by alpha and beta diversity did not explain the variation between low and high FE in grower-finisher pigs.

30 Effects of using different dietary standardized ileal digestible lysine plans on growth performance and carcass characteristics of grow-finish pigs from high or low breeding value boars

Abstract The present study aimed to evaluate the impact of using different dietary standardized ileal digestible (SID) lysine (Lys) plans on growth performance and carcass characteristics of grow-finish pigs coming from high or low breeding value boars. A total of 2,080 pigs (PIC 800 × PIC Camborough) were housed in 20 mixed sex pens (26 pigs/pen), blocked by body weight (BW), and randomly allotted in a 2 × 2 factorial arrangement with boar breeding value (high or low) and nutrition Lys plan (current SID Lys curve recommendation for PIC 800 as % of PIC 337 SID Lys curve or alternative SID Lys curve). Pigs were weaned at 21 d of age (6.1 ± 0.05 kg BW) and followed during the wean-to-finish period until reach the market slaughter weight. Pigs were fed either the current recommendation or an alternative SID Lys curve for PIC 800, in a 6 phase feeding program: phase 1 (6-11 kg; 100 vs 100%, respectively); phase 2 (11-23 kg; 97 vs 100%, respectively); phase 3 (23-45 kg; 97 vs 100%, respectively); phase 4 (45-73 kg; 97 vs 95%, respectively); phase 5 (73-102 kg; 97 vs 95%, respectively); and phase 6 (102-132 kg; 97 vs 90%, respectively). Pigs were fed isoenergetic diets. Performance and carcass traits, and removals and mortality were recorded. Data were analyzed using mixed models in R, and considering pen as the experimental unit for performance traits and individual carcasses for carcass traits. There was no evidence of interaction between boar breeding value and nutrition plan factors. Overall, high breeding value pigs had greater average daily gain (ADG; 0.84 ± 0.005 g/d) compared with low breeding value pigs (0.82 ± 0.005 kg/d; P &amp;lt; 0.01), which was driven by increased average daily feed intake (ADFI; 1.92 ± 0.011 and 1.89 ± 0.011 kg/d, respectively; P &amp;lt; 0.05; Table 1). Moreover, high breeding value pigs had greater hot carcass weight (HCW; 97.8 ± 1.09 kg), carcass yield (74.1 ± 0.23%), backfat thickness (16.3 ± 0.29 mm) and lower lean meat % (57.0 ± 0.21%) compared with low breeding value pigs (96.0 ± 1.09 kg; 73.7 ± 0.23 %; 15.4 ± 0.28; 57.5 ± 0.21%, respectively; P &amp;lt; 0.05; Table 1). Regarding nutrition plan, no significant differences were observed for overall performance traits between pigs fed the current or alternative SID Lys curve (P &amp;gt; 0.05; Table 1). Nevertheless, pigs fed the alternative SID Lys curve had heavier HCW (97.3 ± 1.09 kg) compared with pigs fed the current SID Lys curve (96.6±1.09 kg; P &amp;lt; 0.05; Table 1). No significant differences were observed for overall removals and mortality by breeding value or nutrition Lys plan (P &amp;gt; 0.05). In summary, grow finish pigs from high breeding value boars have an improved productive performance. PIC 800 pigs may achieve the same productive performance with lower lysine levels at the end of the grow-finish period.

PSIII-17 Comparative assessment of New Generation Phytase (HiPhorius vs. Ronozyme HiPhos in growing-finishing pigs

Abstract The aim of the present study was to evaluate the effect of HiPhorius (DSM-Firmenich), a new generation of phytase with improved temperature and pH stability, as a replacement of Ronozyme HiPhos (DSM-Firmenich) on performance of growing-finishing pigs fed corn and soybean meal-based diet. A total of 1,200 growing pigs [PIC genetics, with average initial body weight (BW) = 26.8 ± 0.6 kg] were divided into 60 pens, with each pen consisting of 20 pigs and equal number of gilts and barrows. Each pen within a location block was randomly assigned to one of 4 dietary treatments consisting of 2 sources of phytase (Ronozyme HiPhos and HiPhorius) at a low or a high level of available Phosphorus release (AvP, 0.15 and 0.19% respectively). To achieve a low (0.15%) or high (0.19%) AvP, 1,000 or 2,000 FYT/kg of Ronozyme HiPhos was used respectively. To achieve the same levels of AvP, a decreased inclusion of HiPhorius was used (600 and 1,000 FYT/kg for the low and high AvP, respectively). A five-phase feeding program was utilized until pigs reached market weights. All performance data were analyzed using GLIMMIX procedure in SAS (SAS 9.4, SAS Institute Inc., Cary, NC) in a randomized complete block design with initial body weight as covariate. Least squares means were compared using Fisher’s LSD (P &amp;lt; 0.05). Overall (d 0 to d 92), there were no differences observed in any of the performance parameters [final BW, average daily gain (ADG), average daily feed intake (ADFI), gain to feed ratio (G:F] regardless of the dietary treatments provided (P &amp;gt; 0.20). There were also no differences in mortality and removals (P &amp;gt; 0.20) and in final weight variation (P &amp;gt; 0.20). In summary, using a reduced inclusion rate of HiPhorius (600 and 1,000 FYT/kg) resulted in similar overall growth performance as growing-finishing pigs fed Ronozyme HiPhos at 1,000 and 2,000 FYT/kg, respectively. The present study confirms the improved efficacy of the new generation phytase (HiPhorius) compared with Ronozyme HiPhos.

209 Influence of litter origin on performance and tail biting in growing-finishing pigs

Abstract Tail biting is a multifactorial phenomenon with many aspects contributing to a tail biting outbreak. Little is known about how social structures influence tail biting. Our objective was to determine if litter origin impacts growth performance and tail damage caused by biting behaviors of undocked growing-finishing pigs. Pigs were separated based on their litter origin. Three treatments (12 pens/treatment) were tested: LM = all littermates (all 7 pigs/pen were farrowed and nursed by the same sow), N = non-littermates (7 pigs/pen were farrowed and nursed by 7 different sows), and H = half-group of littermates (7 pigs/pen were farrowed and nursed by 2 sows with 3 or 4 of pigs from each sow). The study was conducted in 2 replications (6 pensּ treatment-1ּ replication-1). Within each replication growth performance, mortality, and morbidity were recorded for 12 wk until pigs reached market weight. Tail damage was evaluated using a subjective scoring system: 0 = no evidence of tail biting; 1 = evidence of chewing without visible blood; 2 = evidence of tail biting with visible blood; 3 = open wounds or abscesses with signs of infection; and 4 = partial or total loss of the tail. Tail damage was assessed weekly during the study period, and the maximal tail score (MTS) that each pig received over the entire 12 wk was recorded. The number of pigs removed and the reason for removal was recorded. Data were analyzed using the mixed procedure of SAS for performance variables with a statistical model including treatment, week, and their interaction as fixed effects, replication as a random effect, and initial body weight as a covariate. A frequency procedure with a chi-square (CMH) tested treatment effects on pigs removed and MTS. Litter origin did not affect average daily feed intake (ADFI), gain to feed ratio (G:F), or pigs removed from each treatment group (all P &amp;gt; 0.19; Table 1), but average daily gain (ADG) of H pigs tended to be greater than that of LM pigs (P = 0.07). Maximal tail score was influenced (P = 0.008) by litter origin treatments. Pigs in LM groups had a greater percentage of MTS 0 compared with H and N groups; and H had greater severity of tail damage with 16.7% of the pigs having an MTS of 3 or greater, while both LM and N had less than 5%. Results of this study suggest that litter origin can influence severity of tail damage caused by tail biting behaviors as indicated by MTS. Future studies should focus on the differences among litter origin treatment groups regarding social interactions to further understand how social structure influences tail biting behaviors.

PSVI-10 Effect of sulfate or hydroxychloride forms of zinc, manganese, and copper on growth performance, weight variation, and carcass characteristics of grow-finish pigs

Abstract A total of 1,026 grow-finish pigs (337 × 1050, PIC; initially 26.0 ± 0.33 kg) were used in a 124-d trial to compare sulfate and hydrochloride forms of Zn, Mn, and Cu on growth performance, carcass characteristics, and weight variation, of grow-finish pigs. Pigs were housed in mixed gender pens with 27 pigs per pen and 19 pens per treatment. The treatments were structured as a completely randomized design and consisted of a control diet containing 150, 16, and 110 mg/kg of Cu, Mn, and Zn, respectively, from sulfate sources or provided by hydroxychloride sources. Experimental diets were corn-soybean meal-corn-dried distiller grains with solubles based and fed in meal form in phase 1 from 26 to 50 kg, phase 2 from 50 to 75 kg, phase 3 from 75 to 100 kg, and phase 4 from 100 to 136 kg. In the grower period (26 to 78 kg), pigs fed sulfate sources of Mn, Zn, and Cu had improved (P = 0.05) gain to feed ratio (G:F) compared with pigs fed hydroxychloride forms (Table). In the finisher period (78 to 136 kg), pigs fed hydroxychloride mineral sources had improved (P = 0.041) average daily gain (ADG) compared with pigs fed sulfate sources. For pig body weight variability, there was no evidence of differences (P &amp;gt; 0.10) in the coefficient of variation between treatments. Pigs fed hydroxychloride mineral sources tended to have greater hot carcass weight (HCW; P = 0.054) when marketed at the end of the study compared with pigs fed sulfate sources, but no evidence for differences (P &amp;gt; 0.10) were found in the first marketing and overall HCW or any other carcass trait at either marketing event. In conclusion, these data suggest there were no differences in overall pig growth performance or body weight (BW) variability, but pigs fed hydroxychloride sources of Zn, Mn, and Cu tended to have heavier HCW at the final marketing event.

142 Evaluation of low SID lysine diets fed to enteric health challenged pigs on wean-to-finish performance

Abstract Producers have been adopting low crude protein or low SID Lys nursery diets to address enteric health concerns. Therefore, we evaluated the longitudinal impact of these strategies on lifetime pig performance. Weaned mixed sex pigs n = 588; initial body weight (BW) = 6.81 ± 1.34 kg] sourced from a poor enteric health flow, were randomly assigned to pens and to one of four nursery dietary treatments, fed for 7 wk. Following the nursery period, pens were then assigned to one of two grow-finish treatments, fed until marketing, to complete a 2 × 2 × 2 factorial design (n = 6 pens/treatment, 12 to 13 pigs/pen). Phase 1 nursery diets were formulated to a 1.10% or 1.40% SID Lys (nLLys or nHLys) with amino acids (AA) provided by both soybean meal (SBM) and crystalline AA or SBM only (nLSBM or nHSBM, respectively). Nursery phase 2 and 3 diets were formulated with a 0.05% decrease in SID Lys while maintaining a 0.30% differential between high and low lysine treatments. Following the nursery, grow-finish pigs were fed diets formulated to equal SID Lys:ME with either a conventional crystalline AA (gfLSBM) or high SBM diet lacking crystalline AA (gfHSBM) to meet AA requirements. During the nursery, enteric health was assessed by fecal pathogen PCRs and bacterial culture, confirming a high natural rotavirus and F18 enterotoxigenic Escherichia coli burden. Pig BW and pen feed disappearance were recorded at the beginning and end of each phase to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (gain to feed ratio; G:F). Data were analyzed with pen as the experimental unit and the fixed effects of nursery SID Lys (nLys), nursery SBM (nSBM), grow-finish SBM (gfSBM), and the two- and three-way interactions using ANOVA. There were no three-way interactions for ADG or ADFI on final performance and no two-way interactions of nLys by nSBM in the nursery. Additionally, there was no effect of nSBM on overall nursery ADG, ADFI, and G:F (P &amp;gt; 0.05). Pigs fed nHLys-gfHSBM (0.84 kg/d) had improved overall ADG versus pigs fed nLLys-gfHSBM (0.80 kg/d; interaction; P = 0.010). Final nursery ADG (0.47 vs. 0.42 kg/d), G:F (0.70 vs. 0.63), and ending BW (30.9 vs. 28.0 kg) were greater in pens fed nHLys compared with nLLys (P &amp;lt; 0.001). Grow-finish pigs fed gfHSBM were more efficient compared with gfLSBM overall (0.457 vs. 0.449, respectively; P = 0.016). Although pigs fed nHLys had improved ending ADG compared with nLLys (0.83 vs. 0.81 kg/d; P = 0.018, respectively), there were no differences in final BW (128.0 vs. 127.0 kg) or ADFI (1.83 vs. 1.80 kg/d; P &amp;gt; 0.05). In conclusion, low SID Lys enteric diets did not improve wean-to-market pig performance in enterically challenged pigs and there was no difference between amino acid sources (crystalline vs SBM).

247 Evaluating the use of soybean hulls on growth performance, carcass composition, and digestibility when fed to grow-finish pigs

Abstract The addition of fiber to grow-finish diets is commonly utilized in swine production formulation as energy costs increase. The objective of this study was to determine the effects of feeding soybean hulls (SBH) at increasing levels to grow-finish pigs on growth performance, carcass characteristics, and apparent total tract digestibility (ATTD) of nutrients. Utilizing 192 grower pigs [PIC 337×1050, initial body weight (BW) = 21.99 ± 2.75 kg] that were randomly assigned to split sexed pens (n = 12 pens/treatment), pens were assigned to one of four dietary treatments and fed over three feeding phases for the estimated BW ranges of 22 to 50 kg, 50 to 86 kg, and 86 to 127 kg. Diets were formulated to represent conventional corn and soybean meal diets, containing increasing levels of SBH at: 1) 0% SBH (0%); 2) 7.5% SBH (7.5%); 3) 15% SBH (15%); and 4) 22.5% SBH (22.5%). Within phase, diets had equal SID Lys:ME and energy was allowed to float. Individual BW and pen feed disappearance were collected for each phase to calculate pen average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency gain to feed ratio (G:F). On d 56 of study and during phase 2, 32 gilts (n = 8) were placed into individual metabolism crates, where total urine and feces were collected for 72 h to measure ATTD of gross energy (GE), nitrogen (N), neutral detergent fiber (NDF), and acid detergent fiber (ADF), then returned to original pens. At the completion of study, carcass weight, backfat depth, and loin depth were collected. Data were analyzed with the fixed effects of dietary treatment by ANOVA, linear, and quadratic contrasts. Pen served as the experimental unit for performance and carcass characteristics and pig as the experimental unit for ATTD analyses. Overall, as SBH increased from 0% to 22.5%, ADG tended to decrease (linear P = 0.060) with no difference in ADFI (P &amp;gt; 0.05), resulting in an overall decrease in G:F (0.38, 0.37, 0.36, 0.35; linear P &amp;lt; 0.001; 0, 7.5, 15 and 22.5% SBH, respectively). Final BW tended to decrease (linear P = 0.069) and carcass weight decreased (102.9, 102.7, 99.7, and 96.5 kg, linear P &amp;lt; 0.001) as SBH increased in diet. Carcass fat depth (P = 0.014) and loin depth (P = 0.006) linearly decreased with increasing levels of SBH in the diet. Increasing levels of SBH from 0% to 22.5% decreased ATTD of GE and N (linear P &amp;lt; 0.001) and tended to increase ATTD NDF and ADF (linear P = 0.056 and P = 0.073, respectively). Altogether, these data suggest increasing dietary SBH in grow-finish pig diets decreases growth efficiency and the digestibility of GE and N. Further, feeding high inclusion rates of SBH negatively impacts carcass yield, backfat and loin depth.