Negative Control Diet Research Articles

Growth performance, physiological response, and tissue microarchitecture of the carp Labeo rohita challenged with AFB1 are improved by supplementing with turmeric

Aim of study: To examine the impact of dietary supplementation with turmeric (TM) (Curcuma longa) on growth, haematological, biochemical parameters, and histoarchitecture in rohu (Labeo rohita) challenged with aflatoxin B1 (AFB1). Area of study: Ludhiana, Punjab, India. Material and methods: A completely randomized design involved the utilization of 225 fingerlings distributed across five treatments with three replicates each. Diets were allocated as follows: T1 denoted the negative control diet, T2 comprised AF100, while T3, T4, and T5 were formulated with AF25TM, AF50TM, and AF100TM, respectively. Main results: The results indicated a negative correlation between AFB1 dosage in feed and fish growth, with higher doses resulting in decreased growth. Significant changes were observed in haematological parameters, including reductions in total erythrocyte count, total leukocyte count, haemoglobin, and packed cell volume, alongside alterations in biochemical parameters, such as decreases in total protein, albumin, and globulin levels, and an increase in glucose levels and albumin/globulin ratio. Additionally, elevated levels of aspartate aminotransferase, alanine aminotransferase, catalase and superoxide dismutase were noted in T2 and T5 compared to other treatments. AFB1 exposure also led to damage in the microarchitecture of the brain, kidney, and liver tissues, although inclusion of TM at 25 ppb AFB1 showed signs of recovery. Research highlights: The changes observed were dose-dependent, and supplementation of TM showed increased resistance against AFB1 and the greatest improvement in T3. Therefore, a diet containing 5 g TM kg-1 would lower AFB1 contamination of 25 ppb compared to 50 and 100 ppb. In conclusion, supplementing TM in fish feeds can help regulating the AFB1, which in turn can improve sustenance-based output.

Novel 4th-generation phytase improves broiler growth performance and reduces woody breast severity through modulation of muscle glucose uptake and metabolism.

The objective of the present study was to determine the effect of a novel (4th generation) phytase supplementation as well as its mode of action on growth, meat quality, and incidence of muscle myopathies. One-day old male broilers (n = 720) were weighed and randomly allocated to 30 floor pens (24 birds/pen) with 10 replicate pens per treatment. Three diets were fed from hatch to 56- days-old: a 3-phase corn-soy based diet as a positive control (PC); a negative control (NC) formulated to be isocaloric and isonitrogenous to the PC and with a reduction in Ca and available P, respectively; and the NC supplemented with 2,000 phytase units per kg of diet (NC + P). At the conclusion of the experiment, birds fed with NC + P diet were significantly heavier and had 2.1- and 4.2-points better feed conversion ratio (FCR) compared to birds offered NC and PC diets, respectively. Processing data showed that phytase supplementation increased live weight, hot carcass without giblets, wings, tender, and skin-on drum and thigh compared to both NC and PC diets. Macroscopic scoring showed that birds fed the NC + P diet had lower woody breast (WB) severity compared to those fed the PC and NC diets, however there was no effect on white striping (WS) incidence and meat quality parameters (pH, drip loss, meat color). To delineate its mode of action, iSTAT showed that blood glucose concentrations were significantly lower in birds fed NC + P diet compared to those offered PC and NC diets, suggesting a better glucose uptake. In support, molecular analyses demonstrated that the breast muscle expression (mRNA and protein) of glucose transporter 1 (GLUT1) and glucokinase (GK) was significantly upregulated in birds fed NC + P diet compared to those fed the NC and PC diets. The expression of mitochondrial ATP synthase F0 subunit 8 (MT-ATP8) was significantly upregulated in NC + P compared to other groups, indicating intracellular ATP abundance for anabolic pathways. This was confirmed by the reduced level of phosphorylated-AMP-activated protein kinase (AMPKα1/2) at Thr172 site, upregulation of glycogen synthase (GYS1) gene and activation of mechanistic target of rapamycin and ribosomal protein S6 kinase (mTOR-P70S6K) pathway. In conclusion, this is the first report showing that in-feed supplementation of the novel phytase improves growth performance and reduces WB severity in broilers potentially through enhancement of glucose uptake, glycolysis, and intracellular ATP production, which used for muscle glycogenesis and protein synthesis.

Validating the use of a newly developed cinnamaldehyde product in commercial broiler production

Essential oils (EOs) have been considered as an alternative to antibiotics for animal production. In the current study, 4 trials were conducted on a commercial broiler farm to investigate the effects of dietary supplementation of an encapsulated cinnamon EO product (NE-OFF) on the bird growth performance, gut health, and gene expression in the ileum, spleen, and liver relating to the host response to heat and other stresses, including potential NE challenge. In each trial, approximately 30,000 Cobb or Ross broilers were randomly allocated to 4 treatments: a raised without antibiotics (RWA) commercial diet as positive control, an adjusted RWA commercial diet as negative control, and the negative control diet supplemented with 2 different dosages of NE-OFF, which was added during feed pelleting. Although the final average body weight did not differ significantly among treatment groups, birds fed NE-OFF had an increased ratio of villus height and crypt depth in the jejunum, and reduced fecal oocyst counts. Trial 2 was conducted in the summer and had a necrotic enteritis (NE) outbreak. The supplementation of NE-OFF reduced the NE incidence and bird mortality. The samples from Trial 2 were hence selected for the analyses of Clostridium perfringens and NetB toxin gene abundance in the ileum, and host responses. The C. perfringens population appeared to be positively correlated with the NetB gene abundance. The gene expression analysis suggested that NE-OFF supplementation improved nutrient absorption and transportation as well as antioxidant activities to help the birds against stress. These on-farm trial results support the hypothesis that the use of NE-OFF as a feed additive can improve bird gut health and performance in commercial broiler production, especially for preventing NE outbreaks when birds are under stress.

Efficiency of Algal oil as a Feed Ingredient for the Development of Maturation Diet for the Spent Penaeus monodon (Fabricius) Spawners

This study designed to understand the effect of Algal oil as feed ingredients to attain reproductive success in the spent spawners of P. monodon. Five diets prepared were D1, D2, and D3 with 2.5%, 5% and 7.5% algal oil respectively, reference diet with fish oil and negative control diet without fish oil. The results showed that the maturation diet increased the moulting frequency and shortened the time of full maturation of the ovary. In D2 fed spawners, the duration of spawnings was minimized and the fecundity was also increased and the Gonado Somatic Index was also high. Compared with control diet, the abortive spawning and gaped ovary formed was also less in algal oil based diet (D2). D2 fed spawners also enhanced the percentage of the formed eggs, fertilized eggs and their hatching and also showed maximum prophenoloxidase activity. Though the reference diet had influenced in all reproductive parameters, the success was inferior to the experimental algal diet. The algal oil (5%) based diet was found to be very efficient in the reproductive success of spent spawners and therefore this diet can be used for the recycling of spent spawners.

Enhancing the Production Performance and Nutrient Utilization of Laying Hens by Augmenting Energy, Phosphorous and Calcium Deficient Diets with Fungal Phytase (Trichoderma reesei) Supplementation

A ten-week trial was conducted to evaluate the enhancement of production performance and nutrient utilization of laying hens through augmenting energy, phosphorous, and calcium deficient diets with fungal phytase (Trichoderma reesei) supplementation. 720 Hy-line Brown hens aged 28 weeks were randomly divided into 5 groups; each group had 8 replicates of 18 hens. Five experimental diets were prepared and fed to corresponding groups. A positive control (PC) diet contained 3.50% of calcium (Ca), 0.32% of non-phytate phosphorus (NPP), and apparent metabolic energy (AME) of 11.29MJ/kg, while a negative control (NC) diet contained 3.30% of Ca, 0.12% of NPP, and lower AME of 300 kJ/kg. The other three diets were supplemented with 250 FTU/kg phytase (PHY-250), 1000 FTU/kg phytase (PHY-1000), and 2000 FTU/kg phytase (PHY-2000) in addition to a regular NC diet. Results indicated that the positive control (PC) diet group had higher body weight gain, egg weight, and average daily feed intake. However, laying rate, egg mass, and FCR were most improved in the PHY-2000 group, followed by the PHY-1000 and PHY-250 groups (p < 0.05). Improved yolk color was most notable in laying hens fed the diet with PHY-1000 as opposed to the PC and NC groups (p < 0.05), but no overall difference was found among all of the phytase treated groups. The apparent availability of dry matter, energy, phosphorus, and phytate P was significantly higher in the PHY-2000 group than in the PC and NC groups (p < 0.05). Compared to the PC group, nitrogen retention was significantly higher in the PHY-1000 group, while calcium availability was higher in the PHY-250 group. The results suggested that the addition of phytase to diets with low P, Ca, and AME improved laying performance and apparent availability of dietary nutrients. Thus, it was concluded that the laying hen diet could be supplemented with 1000–2000 FTU/kg phytase for improving laying production and nutrient availability and mitigating the negative impact of reduced nutrient density in laying hen diets.

Fermentation of Plant-Based Feeds with Lactobacillus acidophilus Improves the Survival and Intestinal Health of Juvenile Nile Tilapia (Oreochromis niloticus) Reared in a Biofloc System.

This study evaluated the effect of fermentation with Lactobacillus acidophilus on the biochemical and nutritional compositions of a plant-based diet and its effects on the productive performance and intestinal health of juvenile Nile tilapia (Oreochromis niloticus) reared in a biofloc technology (BFT) system. The in vitro kinetics of feed fermentation were studied to determine the L. acidophilus growth and acidification curve through counting the colony-forming units (CFUs) mL-1 and measuring the pH. Physicochemical and bromatological analyses of the feed were also performed. Based on the microbial growth kinetics results, vegetable-based Nile tilapia feeds fermented for 6 (FPB6) and 18 (FPB18) h were evaluated for 60 days. Fermented diets were compared with a positive control diet containing fishmeal (CFM) and a negative control diet without animal protein (CPB). Fermentation with L. acidophilus increased lactic acid bacteria (LAB) count and the soluble protein concentration of the plant-based feed, as well as decreasing the pH (p < 0.05). FPB treatments improved fish survival compared with CPB (p < 0.05). Fermentation increased feed intake but worsened feed efficiency (p < 0.05). The use of fermented feeds increased the LAB count and reduced pathogenic bacteria both in the BFT system's water and in the animals' intestines (p < 0.05). Fermented plant-based feeds showed greater villi (FPB6; FPB18) and higher goblet cell (FPB6) counts relative to the non-fermented plant-based feed, which may indicate improved intestinal health. The results obtained in this study are promising and show the sustainable potential of using fermented plant-based feeds in fish feeding rather than animal protein and, in particular, fishmeal.

Effects of Tannic Acid Supplementation of a High-Carbohydrate Diet on the Growth, Serum Biochemical Parameters, Antioxidant Capacity, Digestive Enzyme Activity, and Liver and Intestinal Health of Largemouth Bass, Micropterus salmoides.

We investigated the effects of dietary tannic acid (TA) supplementation of a high-carbohydrate diet on growth, feed utilization, whole-body proximate composition, serum biochemical indicators, antioxidant capacity, digestive enzyme activity, and liver and intestinal health of juvenile largemouth bass, Micropterus salmoides (initial mean weight: 8.08 ± 0.08 g). Five diets were prepared, including a positive control (dietary carbohydrate level, 16%, LC0), a negative control (dietary carbohydrate level, 21%, HC0), and three TA-supplementation diets based on the negative control diet with TA addition at 200, 400, and 800 mg/kg, respectively. After 8 weeks of feeding, the results showed that compared with the LC0 diet, 400-800 mg/kg dietary TA significantly improved the survival rate of largemouth bass (P < 0.05) while significantly reducing its weight-gain rate and specific growth rate (P < 0.05). Compared with the HC0 diet, 400 mg/kg dietary TA significantly increased serum catalase activity (P < 0.05), and significantly decreased serum malondialdehyde, liver glycogen, lightness (L ∗), and yellowness (b ∗) (P < 0.05). Moreover, compared with the HC0 diet, 200-400 mg/kg dietary TA effectively improved the vacuolation of hepatocytes caused by the high-carbohydrate diet and reduced the occurrence of intestinal epithelial cell vacuolation and necrosis. In turn, 800 mg/kg dietary TA significantly inhibited protease activity in the pyloric caecum and intestine (P < 0.05). In conclusion, dietary supplementation with TA inhibited protease activity, which resulted in decreased growth performance in largemouth bass. However, it was also found that 200-400 mg/kg TA enhanced the antioxidant capacity of largemouth bass in the case of the high-carbohydrate diet, reduced liver glycogen levels, and improved liver and intestinal health. Finally, it should be noted that, when the dietary TA level exceeded 800 mg/kg, TA appeared to play a pro-oxidation role in the liver, which may cause oxidative stress in the liver.

Inorganic Phosphorus Supplementation in Diets for Farmed Shrimp: Performance and Digestibility of Juvenile Litopenaeus vannamei Fed Monosodium Phosphate, Monoammonium Phosphate, Magnesium Phosphate, and Monocalcium Phosphate

Inorganic phosphates have been used in shrimp feeds to meet phosphorus (P) needs, which may be quantitatively affected by the dietary content of P and other minerals and digestibility. In the present study, performance and digestibility were determined simultaneously in juvenile shrimp (Litopenaeus vannamei) during the grow‐out period (4–23 g ind wt). Shrimps were fed plant‐based diets supplemented with different phosphate ingredients: monosodium phosphate (MSP), monoammonium phosphate (MAP), magnesium phosphate (MgP), and monocalcium phosphate (MCP). The total P level in test diets was 0.79%. MSP supplementation was tested at two dietary calcium:phosphorus ratios to check for possible effects upon shrimp performance and digestibility. A negative control diet was tested with a similar formulation without inorganic phosphate supplementation (0.47% total P). Shrimp was reared in a recirculated clear water tank system (35 ppt salinity, 30°C, 100 individuals/m3) with continuous feeding provided by automatic pellet delivery. Feces were sampled 4–5 times daily throughout the trial. A negative control diet produced P limitation and significantly reduced shrimp performances compared to P‐supplemented diets (P &lt; 0.05). Performance of shrimp‐fed diets containing inorganic phosphates varied for feed conversion rate: 1.24–1.34, survival: 87%–94%, growth: 2.50–2.59 g/week, and no significant difference was found among dietary treatments (P &gt; 0.05). Inorganic P supplementation resulted in significantly higher dry matter, crude protein, ash, and P apparent digestibility coefficient (ADC) compared to P limited negative control diet (P &lt; 0.05). In addition, reduced P ADC (P &lt; 0.05) was checked with higher dietary Ca:P ratio. Phosphorus digestibility in test diets showed significant differences: MSP &gt; MCP, MgP, and MSP + CaCO3; MAP &gt; MSP + CaCO3 (P &lt; 0.05). Digestible P (%) could then be calculated in test diets: MgP (4.77 g Pdig/kg of feed), MSP + CaCO3 (4.81 g Pdig/kg of feed), MCP (5.0 g Pdig/kg of feed), MAP (5.13 g Pdig/kg of feed), and MSP (5.30 g Pdig/kg of feed). Digestible P in phosphate sources (%) could then be calculated: 88.2% MSP, 84.2% MAP, 79% MCP, 72.2% MgP, and 71.8% MSP + CaCO3. Shrimp whole body and exoskeleton phosphorus content also showed significantly higher values in P‐supplemented diets compared to control, regardless of the source tested (P &lt; 0.05). It is concluded that tested phosphates were suitable for feeding juvenile shrimp with MSP, MAP, and MgP diets showing high feed efficiency, while MSP and MAP diets resulted in numerically increased growth, coinciding with numerically higher P digestibility in these phosphates. The elevated P digestibility in the phosphates seems related to their water solubility, though MgP, less soluble and digestible in comparison to MSP and MAP, could also produce good performance.

Responses in weanling pigs fed low protein diets supplemented with dietary nucleotides.

Evidence suggests that nucleotide supplementation in diets improves intestinal development, immune function, and cell growth. Stressful events such as weaning in pigs may increase nucleotidedemand, making exogenous supplementation potentially beneficial. This study evaluated the effects of low-protein (LP) diets supplemented with dietary nucleotides on growth performance, postweaning diarrhea (PWD), nutrient digestibility, and blood metabolites. A total of 210 piglets were weaned at 21 d of age, allowing a 3-d adaptation to a common nursery diet. At 24 d, pigs were reweighed (6.02 ± 0.05kg) and allocated to 5 dietary treatments in a randomized complete block design to give 7 replicates per treatment (n = 6 piglets per replicate). The 5 dietary treatments included (i) a high protein positive control diet (PC) with 24% crude protein (CP); (ii) a low protein negative control (NC) with 16% CP; (iii) an NC diet with nucleotide supplementation at 1g/kg (NC01), 3g/kg (NC03), or 9g/kg (NC09). Diets were provided ad libitum for 35 d, and weekly feed intake (FI) and body weight (BW) were recorded. Blood samples were collected on day 32 and fecal samples were collected on days 33, 34, and 35 to determine serum metabolites and nutrient digestibility, respectively. Relative to PC, the NC diet had lower overall average daily gain (ADG) (343.5 vs. 305.5g/d), incidence of PWD (2.5 vs. 1.2 diarrhea score), and blood urea nitrogen (BUN) (11.3 vs. 3.4mg/dL); (P < 0.05, < 0.05, and < 0.0001, respectively). The nucleotide-supplemented diets, NC01, NC03, and NC09, had comparable (P > 0.05) overall ADG to the PC and decreased (P < 0.0001) BUN. Additionally, NC09 had decreased (P < 0.05) incidence of PWD compared to PC. The apparent total tract digestibility (ATTD) of nitrogen increased linearly (P < 0.05) with nucleotide supplementation, although reducing CP decreased (P < 0.05) serum glutathione and insulin-like growth factor-1 (IGF-1) concentrations. However, IGF-1 concentration was linearly increased (P < 0.05) with nucleotide supplementation. Results suggest that feeding LP diets supplemented with dietary nucleotides after weaning can increase ATTD of nitrogen and protein utilization, reduce the incidence of PWD, and increase serum IGF-1 concentration while partially ameliorating the negative effects of LP diets on growth performance.

Funcionalidade nutricional do complexo xilanolítico obtida de Aspergillus japonicus var. aculeatus UFMS 48.136 em dietas para suínos

Abstract The objective of this study was to evaluate the nutritional functionality of the xylanolytic complex produced from Aspergillus japonicus var. aculeatus UFMS 48.136 isolated from the Cerrado/ Pantanal biome in Mato Grosso do Sul, compared to commercial xylanase, in swine diets. Sixteen barrows were used, with an initial weight of 64.23 ± 10.5 kg, distributed in a randomized block experimental design, with four diets: control, formulated according to nutritional recommendations; negative control, formulated with a reduction of 100 Kcal / kg of metabolizable energy (ME); negative control + xylanase Cerrado / Pantanal; negative control + commercial xylanase; with four repetitions each. The xylanase supplementation provided higher (P&lt;0.05) values of digestible energy (DE), ME, and higher (P&lt;0.05) digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), and acid detergent fiber (ADF) in relation to the negative control diet, but without differing (P&gt;0.05) from the control diet. The inclusion of xylanases increased (P&lt;0.05) in the coefficients of digestibility (CD) and metabolism of crude energy (CE), DM, OM, CP, EE, NDF, and ADF. There was no difference (P&gt;0.05) in digestibility and CD values between Cerrado/Pantanal and commercial xylanase. The inclusion of xylanases made it possible to reduce 100 Kcal of ME per kilogram of diet. Cerrado/Pantanal xylanases therefore have the same nutritional efficiency as commercial xylanases.

Effects of dietary microbial protease on growth performance, nutrient apparent digestibility, hepatic antioxidant capacity, protease activities and intestinal microflora in juvenile genetically improved farmed tilapia, Oreochromis niloticus

The study was to evaluate the effects of four types of microbial protease on growth performance, nutritional composition, apparent digestibility coefficients (ADC), physiological parameters and microbiota of genetically improved farmed tilapia (GIFT, Oreochromis niloticus). Six diets were prepared, including a positive control diet (protein 300 g/kg, high protein group, HP) and one negative control diet (protein 280 g/kg, low protein group, LP) and four proteases were added to the low protein diets, included HuPro protease (LPH), acid protease (LPAC), neutral protease (LPN) and alkaline protease (LPAK). Compared with the fish fed LP diet, the weight gain rate (WGR), specific growth rate (SGR), feed conversion rate (FCR), protein efficiency ratio (PER) and feed intake ratio (FIR) were improved in fish fed LPH diet. The ADC of dry matter in LPH diet was improved. The serum total protein (TP) in LPH diet was higher than the LP diets. The activities of total antioxidant capacity (T-AOC) and catalase (CAT) in LPH group was higher than the LP and HP group, respectively. The protease activities of stomach and gut in fish fed LPH diet was higher than LP group. Shannon and Simpson indices in LPH group were higher than the LP group. The abundance of Fusobacteria in the six groups reached more than 70 % at the phylum level, and the largest difference in the relative abundance at the genus level was Cetobacterium. In conclusion, this study demonstrates the positive effects of HuPro protease on tilapias and selection of HuPro protease to the low protein diet is suitable.

The addition of humic substances extracted from vermicompost enhances the growth performance and the antioxidant status of weaning pigs

The aim of the study was to assess the effect of humic substances (HS) extracted from vermicompost on the growth performance, fecal score, bone ash content and antioxidant status in muscles and blood serum of weaned pigs from 1-42 days postweaning. Two-hundred 22-day weaned pigs were assigned to four treatments: 1= Positive control diet with colistin (PC), 2= Negative control diet without antibiotic or HS (NC), 3 and 4= Diets with 2 500 and 5 000 ppm of HS, respectively. Growth performance, fecal consistency, dry matter and ashes of metatarsus and the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, iron reducing ability and thiobarbituric acid reactive substances in muscles and blood were registered. Results were subjected to ANOVA and regression analysis. Linear increasing responses (P &lt; 0.05) were found in the body weight at 42 days postweaning, the ADG from 1-7, 8-21, 22-42 and 1-42 and the gain:feed ratio from 1-7, 22-42 and 1-42 days postweaning, whilst the fecal score decreased linearly (P &lt; 0.01) from 1-7, 8-21 and 1-42 days postweaning due to the increasing dietary HS concentration. The antioxidant potential of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (P &lt; 0.05) in loin muscle and blood serum at three and seven days, and in fillet muscle at seven days postweaning increased linearly due to the increasing dietary HS concentration. It is concluded that the addition of HS improved the growth performance from 1-42 days postweaning and the antioxidant status in muscles and blood serum of weaned pigs at three and seven days postweaning.

Optimal dietary supplementation of phytase for red drum (Sciaenops ocellatus) based on growth and mineral utilization

A 9-week feeding trial was conducted with juvenile red drum to evaluate the potential benefits of supplementing dietary phytase on growth performance and utilization of phosphorus (P) and various trace minerals. The negative control diet (0.9% of total P and 0.57% of available P) was formulated to have inadequate available P based on the established P requirement of red drum. The positive control diet contained extra monocalcium phosphate (MCP) to provide 0.73% available phosphorus to meet the red drum's minimum P requirement. Another four phytase-supplemented diets were made via adding Quantum Blue phytase (AB Vista, Plantation, Florida) at either 1000, 2000, 4000, or 8000 phytase units (FTU)/kg to the negative control diet. Each diet was fed to quadruplicate groups of 20 juvenile red drum (initial weight of 4.99 ± 0.09 g) in 110-L aquaria operated as a brackish water (7 ppt) recirculating aquaculture system for 9 weeks. The results showed that compared to red drum fed the negative control diet, fish fed the phytase-supplemented diets had significantly (P < 0.05) increased weight gain, feed efficiency, and protein retention. In addition, significantly increased apparent availability of P was observed in red drum fed the diets containing phytase compared to those fed the negative control diet. Red drum given the phytase-supplemented diets also had significantly enhanced utilization of various minerals, except for whole-body retention of Mn and bone deposition of Fe, compared to fish fed the negative control diet. According to the results based on the orthogonal polynomial contrasts, the optimal dietary phytase dosage was found to be 5520 FTU/kg of dry diet. Consequently, the supplementation of dietary phytase significantly improved growth performance of red drum and partly substituted for dietary MCP in diets containing 40% soybean meal and insufficient available P. In addition, dietary phytase supplementation significantly enhanced the utilization of dietary protein and various minerals by red drum.

104 Development of an Experimental Model to Induce Liver Abscesses in Steers Using an Acidotic Diet Challenge and Oral Bacterial Inoculation

Abstract The objective of this study was to develop a model for liver abscesses (LA) in Holstein steers by using an acidotic diet or acidotic diet plus intraruminal inoculation of Fusobacterium necrophorum, Salmonella enterica serotype Lubbock, and Truperella pyogenes. Holstein steers (n = 40; initial BW = 84.9 + 7.1 kg) were individually housed and randomly assigned to either a negative control diet (CON), an acidotic diet (AD), or an acidotic diet plus intraruminal inoculation with the bacterial mixture [ADB; (1 × 109 colony forming unit (CFU)/mL of each bacteria]. Steers in AD and ADB were cycled on (3 d) and off (2 d) a high-starch diet 20 days before intraruminal inoculation of ADB. Following inoculation, AD and ADB remained on the acidotic diet for the remainder of the study. Ruminal pH boluses were randomly inserted into 19 steers across treatments to monitor ruminal pH throughout the study. Steers were euthanized and necropsied to record gross pathology on the lung, rumen, liver, and colon. Culture techniques were used to determine the prevalence inoculated bacteria within LA. Quantitative polymerase chain reaction methods were used to quantify F. necrophorum in rumen tissue. Data were analyzed as a completely randomized design with animal as the experimental unit, where an α of ≤ 0.05 determined significance. Liver abscess prevalence was 43% in ADB vs. 0% in AD and CON treatments (P &amp;lt; 0.01). Ruminal damage was 51.1% greater in ADB than in AD and 78.6% greater than in CON (P ≤ 0.05). There were no pathological differences in the lungs and colons among treatment groups (P ≥ 0.14). There was a treatment × time interaction for ruminal pH, where pH decreased below 5.6 in AD and ADB calves during each cycle of the acidotic diet (P &amp;lt; 0.01). The ADB contained a greater concentration of F. necrophorum subsp. Necrophorum and subsp. Fundliforme within rumen tissue (P ≤ 0.03). Of the LA cultured, 100% contained F. necrophorum, 50% S. enterica, and 0% contained T. pyogenes. The F. necrophorum subsp. Necrophorum was phylogenetically typed and identical to the strain (FN-8LI) infused in the bacterial inoculation. These data suggest that acidotic diet in combination with intraruminal inoculation of the bacterial mixture is sufficient to induce liver abscesses and provides insight on possible mechanisms and origins of LA. Further studies are needed to validate these results and determine if this model may be used to study novel intervention methods.

271 Effect of Different Inclusions of a Multi-Component Enzyme on Performance, Nutrient Digestibility, and Ileal Amino Acid Digestibility of Young Broiler Chickens

Abstract Previous studies demonstrated that dietary carbohydrases maintain optimal broiler performance. The objective of this experiment was to evaluate the effects of a commercial carbohydrase (ENZ) at 4 concentrations on growth performance, nutrient, and amino acid digestibility of 22-d-old broilers. The 10 experimental corn and soybean meal-based treatments were: 1) a positive control diet (PC) with phytase at 500 FTU/kg of feed (PHY), 2) a mid-control diet (MC) with a 115 kcal/kg reduction in energy + PHY, 3) a negative control diet (NC1) with a 223 kcal/kg reduction in metabolizable energy, 4-5) NC1 + ENZ at 1,000 or 3,000 xylanase units (XU)/kg (NC1A and NC1B, respectively), 6) NC1 + PHY (NC2), and 7-10) NC2 + ENZ at 1,000, 2,000, 3,000, or 4,000 XU/kg (ENZ1, ENZ2, ENZ3, and ENZ4, respectively). Day-old chicks (n = 1,000) were randomly allotted to raised floor pens with 5 birds/pen and 20 replicate pens/treatment. Pens had perforated metal platforms to allow excreta collection. On day 22, broilers were euthanized, and ileal digesta samples were collected from the entire ileum. Protein retention, nitrogen-corrected apparent metabolizable energy (AMEn), and ileal digestibility of protein and amino acids (AA) were determined. Performance data were calculated from d 6 to 22. Means were separated with the PDIFF option of SAS V9.4 PROC GLIMMIX at P ≤ 0.05. On d 22, broilers from PC and MC treatments had greater body weight (BW) than all other treatments (P &amp;lt; 0.0001). The least feed intake was reported in birds fed ENZ1 diet, but it was similar to NC1, NC1B, and ENZ3-fed broilers (P &amp;lt; 0.0472). Broilers fed PC and MC had the greatest BW gain; however, ENZ2-fed broilers were able to gain similarly as MC treatment (P &amp;lt; 0.0001). Broilers fed PC diet had the best feed efficiency, followed by MC-fed broilers, but these were similar to ENZ3 (P &amp;lt; 0.0001). Protein retention was the greatest for MC-fed broilers but was similar for NC1B and ENZ3 (P &amp;lt; 0.0001). AMEn was greatest for broilers fed PC and MC diets, followed by both diets that included 3,000 XU/kg (P &amp;lt; 0.0001). Protein digestibility was greatest for ENZ2-fed broilers (P &amp;lt; 0.0001) but similar to MC, NC1B, NC2, ENZ3, and ENZ3. Treatments with added PHY, excluding ENZ1, had greater lysine digestibility compared with all other treatments (P &amp;lt; 0.0001). Apart from threonine, ENZ4-fed broilers exhibited the greatest AA digestibility but were similar to broilers fed 2,000 or 3,000 XU/kg of ENZ (P &amp;lt; 0.0001). Therefore, ENZ inclusion above 1,000 XU/kg supported AA digestibility. Overall, broilers fed diets with 223 kcal/kg energy reduction and supplemented with 2,000 and 3,000 XU/kg outperformed the negative controls, which could be partially due to the utilization of dietary energy and nutrients.

103 Development of a Novel, Experimental, Minimally Invasive Model to Investigate the Genesis and Etiology of Liver Abscesses in Cattle

Abstract Most research surrounding liver abscesses involves post-hoc evaluation of naturally occurring abscesses in production settings. Few studies have been designed to experimentally induce abscesses with the purpose of identifying a time course, causality, and associated physiological implications. Therefore, we set out to develop a minimally invasive, reliable, and repeatable model to induce liver abscesses in calves in a controlled research environment to elucidate the genesis and etiology of the disease, with the ultimate goal of developing abscess reduction strategies. Experiment 1 was an attempt to induce abscesses by intraruminal inoculation with Fusobacterium necrophorum, Salmonella lubbock, and Truperella pyogenes (FST) following an intravenous lipopolysaccharide challenge. Holstein steers were harvested 3- and 10-d after inoculation, but no abscesses were detected. Experiments 2 and 3 involved diet manipulation by cycling calves on and off a high-starch, acidotic diet followed by intraruminal inoculation of microbes. In Experiment 2, Holstein calves were fed a negative control diet, an acidotic diet, and an acidotic diet plus bacterial inoculation with FST. No abscesses formed in the control or acidotic diet calves, but 43% of calves fed the acidotic diet with FST inoculation formed liver abscesses, suggesting that acidosis alone is insufficient to produce abscesses. In Experiment 3, treatments consisted of Holstein steers fed a negative control, an acidotic diet, an acidotic diet plus ruminal Fusobacterium necrophorum (F), and an acidotic diet plus Fusobacterium and Salmonella (FS). Again, there were no abscesses in the control or calves fed an acidotic diet alone; however, 40% of calves receiving F presented with an abscess, and 50% of the calves that received FS presented with abscesses. These data suggest that ruminal acidosis in conjunction with a ruminal load of pathogens commonly associated with liver abscesses provides a model that will induce liver abscesses. While the role of barrier dysfunction in the rumen and the lower gastrointestinal tract in formation of abscesses is not fully understood, this work provides a foundation to further explore the etiology of this disease and potential mitigation strategies.

Feed emulsifier improves the performance and nutrient digestibility in broiler chicken fed diets without antibiotic growth promoter

ABSTRACT 1. A study was conducted to assess the impact of supplementing-graded concentrations of emulsifier on the production performance, gut microbial count, and digestibility of nitrogen and energy in broiler chicken fed diets without AGP. 2. Male broiler chicks (n = 1500; Vencobb-430), aged one-day-old, were randomly allocated into six dietary groups each with 10 replicates of 25 birds each. A maize-soybean and meat and bone meal-based basal diet without antibiotic (AGP) growth promoter served as negative control (NC). The basal diet was supplemented with BMD (AGP, bacitracin methylene disalicylate-BMD 100 g/T), which served as the positive control (PC). Emulsifier was added to the NC diets at either 250 g/ton in all phases (250-All), 250 g in starter and grower phases, and 500 g in the finisher phase (250:250:500), 250 g in starter and 500 g in both grower and finisher phases (250:500:500) and 500 g in all phases (500 g-All). 3. Two broilers per replicate were slaughtered to record carcase traits and gut microbial count on day 43. There was significant improvement in body weight gain (BWG) and reduced FCR in broilers fed 250:250:500 and 250:500:500 g emulsifiers compared to other treatment groups. Carcase traits and faecal microbial count did not differ among treatments. The inclusion of BMD significantly improved nitrogen (N) digestibility compared to the NC group. The digestibility of emulsifier-supplemented groups was similar to those fed by the BMD group except for the 500-All group, which was an intermediary between NC and other emulsifier-fed groups. 4. It was concluded that supplementation with emulsifier (250:250:500 or 250:500:500) without antibiotic growth promoter significantly improved FCR and body weight gain similar to broilers receiving antibiotic growth promoter, which was associated with increased ileal digestibility of N and energy.

248 Concentration of Net Energy in Corn without or with Microbial Phytase Fed to Group-Housed Pigs

Abstract The objective was to test the hypothesis that addition of microbial phytase to corn increases net energy (NE) by group-housed growing pigs. Three diets were formulated. The positive control (PC) diet contained corn as the sole source of energy. The PC diet contained Ca and P at the requirements for pigs (NRC, 2012). The negative control (NC) diet was similar to the PC except that this diet contained 0.08% standardized total tract digestible P and 0.12% total Ca less than the PC diet. The third diet was similar to the NC diet with the exception that this diet contained 1,000 units of phytase per kg diet. Pigs were allowed ad libitum access to feed and water. Pigs (n = 24; initial body weight = 44.99 kg; SD = 2.09) were allotted to the 3 diets using a replicated 6 × 3 incomplete Latin square design with 6 chambers (i.e., 4 pigs/chamber) and 3 periods. Oxygen consumption and CO2 and CH4 production were measured during fed and fasting states and fecal and urine samples were quantitatively collected. The statistical model included diet as the fixed effect and chamber and period as random effects. Result indicated that the apparent total tract digestibility (ATTD) of dry matter and gross energy, energy excretion in feces, urine, and heat, and NE did not differ among the 3 diets (Table 1). However, concentrations of digestible energy (DE) and metabolizable energy (ME) in diets and in corn were less (P &amp;lt; 0.05) in the PC diet compared with the NC diet without phytase, but no difference was observed between the PC diet and the NC diet with phytase or between the 2 NC diets. The ratio between NE and ME was not different among diets, but ME to DE was increased (P &amp;lt; 0.05) by supplementation of phytase to the NC diet. In conclusion, concentrations of DE and ME in corn are less if more feed phosphate and limestone are used in diets. However, concentrations of NE were not affected by supplemental phytase or Ca and P levels, even though ME to NE was increased by supplemental phytase.

PSV-6 Evaluation of Narasin Feeding Duration on Growth Performance and Carcass Characteristics of Growing-Finishing Pigs

Abstract Previous studies evaluating 15 mg/kg narasin have shown improvements in BW, ADG, G:F, and HCW and carcass yield when fed for an extended period of time ( &amp;gt;60 days). However, a detailed evaluation of feeding duration of narasin has not been completed. This study evaluated the effect of narasin feeding duration on growth performance and carcass characteristics of growing-finishing pigs. The study was carried out over a fixed time of 112 days using 1,644 pigs in a randomized complete block design. Narasin was included at 15 mg/kg in the last two, three, or four growing-finishing dietary phases, which resulted in narasin being fed for the last 68, 94, or 112 days of study and compared with a negative control diet. Pigs were fed diets that met or exceeded nutrient recommendations of growing-finishing pigs (NRC, 2012). Pigs were offered ad libitum access to feed and water throughout the study and weighed every 28 days and at every marketing event. Feed additions and feed remaining in the feeder at the time of pig weighing were recorded. Pigs were sent for harvest to a commercial slaughter facility in three marketing groups: Group 1 – 20% of pigs marketed on day 84 of study, Group 2 – 20% of pigs marketed on day 98 of study, and Group 3 – remaining 60% of pigs marketed on day 112 of study. Standard carcass grading measurements were collected for each pig and summarized by pen for data analysis. There were limited statistical differences (P &amp;gt; 0.05) between treatments for growth or carcass measures, likely due to the limited number of replicates (n = 16) in this research facility. Nonetheless, there were numerical improvements from feeding narasin. Final live BW (+0.3, +0.4, +1.5 kg, respectively) and ADG (+0.1, +0.4, and +1.3%, respectively; Table 1) numerically increased with increased feeding duration of narasin. Overall G:F was relatively unaffected by feeding duration. Hot carcass weight increased with increased narasin feeding duration (+0.2, +1.1, +1.9 kg, respectively), resulting in increased carcass yield with increased feeding duration (-0.2, +0.1, +0.4 percentage units, respectively). Collectively, carcass ADG and carcass G:F trended toward improvement with increased feeding duration. Results of this study confirm previously observed improvements in growth performance from extended feeding of narasin compared with controls, suggesting that a greater response to narasin is observed with longer feeding durations.

150 A new Bacterial Phytase can act as an Overdose Concept, at low Levels, in Improving the Performance and Carcass Characteristics of Nursery and Finishing Pigs

Abstract This study aimed to evaluate the effect of doses of a new bacterial phytase (HiPhorius, DSM Nutritional Products) on the performance and carcass characteristics of pigs in the nursery and finishing phases. Barrows and gilts (n = 250, 21 d-old and initial body weight (BW) = 6.07 ± 0.73 kg were randomized in blocks design and submitted to 5 treatments. The pigs were fed five corn-soybean meal-based diets: positive control (PC), supplemented with inorganic phosphorus and calcium; negative control (NC), with 0.18% reduction in available phosphorus and 0.16% in calcium; and three NC diets supplemented with 600, 1,200 and 1,800 phytase units (FYT)/kg in the feed. Daily BW (DWG), daily feed intake (DFI), feed conversion rate (FCR), and BW were measured at the end of each phase: pre-starter I (21-28d), pre-starter II (28-35d), starter I (35-49d), starter II (49-63d), growing I (63-91d), growing II (91-112d), finishing I (112-133d) and finishing II (133-156d) phases. Carcass yield, back fat height, loin depth, and lean meat yield were measured in the 156 d-old. Data were submitted to ANOVA, Tukey test and regression analysis. In the nursery (21-63d) diets with phytase levels were similar to PC for FCR (P &amp;gt;0.05) and better to NC, with a quadratic effect (FCR = 1.671 - 0.0003X + 0.00000010526X2), being the best point 1,320 (FYT). The supplementation with phytase in grow-finishing phases (63 -156 d) were similar to PC (P &amp;gt; 0.05) for DWG, DFI and FCR (P &amp;lt; 0.05) and better than NC, which were identified a regression effect (DWG = 0.8543 + 0.0001X; DFI = 2.1453 + 0.0007X - 0.00000029618X2; FCR = 2.6924 - 0.0004X + 0.00000012768X2), with the best levels of phytase of 1,296 and 1,404 FYT for DFI and FCR, respectively. The supplementation of phytase improved the carcass yield, loin depth, kilogram of lean meat and percentage of lean meat when compared with NC diet. Supplementing levels of HiPhorius to a corn and soybean meal-based diet with inorganic P and Ca reduction improved performance and carcass traits of pigs after weaning until slaughter age.