Apparent Ileal Digestibility Of DM Research Articles

PSI-14 Effect of dietary xylanase supplementation on growth performance, nutrient digestibility, and digesta viscosity of weaned pigs fed wheat-soybean meal-based diets

Abstract Xylanase supplementation can improve nutrient digestibility in pig diets by degrading cell wall non-starch polysaccharides and reducing digesta viscosity as well as promoting intestinal health of pigs after weaning. This study determined the effects of dietary xylanase supplementation on growth performance, apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients, and digesta viscosity in different digestive sites of weaned pigs. A total of 312 weaned pigs [body weight (BW) = 5.1 ± 0.9 kg] were weaned into 48 pens and assigned to one of six dietary treatments, each treatment with 8 pens, 6 to 7 pigs per pen, and sex ratios maintained within BW blocks. Experimental diets were formulated in a 3-phase nursery feeding program: Phase 1 (d 0 - d 7), Phase 2 (d 8 - d 21), and Phase 3 (d 22 – d 42). Experimental diets consisted of a wheat/soybean meal-based diet formulated to meet pig requirements (positive control, PC), the PC diet with reduction of 100 kcal of ME (negative control, NC), and the NC diet supplemented with either 900, 1,800, 3,600, or 7,200 units of xylanase. Feed disappearance and body weight were measured at d 7, 14, 21, and 42. Pen fecal score was assessed daily during d 0 to 14 and three times a week during d 15 to 28. On d 21 to 24 of the experiment (12 pigs per day), one pig per pen was selected for sample collection: ileal, cecal, and mid-colon digesta for viscosity and ileal digesta and feces for nutrient digestibility. Orthogonal polynomial contrasts were used to determine the linear and quadratic effects of increasing levels of xylanase in NC diets. Contrast analysis was used to compare PC and NC groups with xylanase-supplemented groups. Fecal score data were analyzed using the PROC FREQ procedure. Supplementing xylanase to NC diets did not improve pig growth performance (P > 0.05) through the nursery period. In wk 2 and wk 3, pigs fed the PC and NC diets had a greater (χ2 < 0.05) incidence of fecal scores 3 & 4 (diarrhea) than the xylanase-supplemented pigs. The AID of DM and ATTD of crude protein, gross energy, and NDF were greater (P < 0.05) in the PC and 900-xylanase supplemented diets than in the other dietary treatments. In addition, the ATTD of NDF and ADF increased linearly (P < 0.1) in response to xylanase supplementation. Xylanase supplementation (900 to 7,200 U) decreased digesta viscosity in colon when compared with PC and NC diets. Overall, xylanase supplementation can improve nutrient digestibility, particularly at total tract level, and reduce viscosity in the hindgut, which could be related with decreasing the occurrence of looseness. However, the effects on growth performance were not expressive when xylanase was supplemented to wheat-soybean meal-based diets with reduction of 100 kcal of ME.

Efficacy of a novel multi-enzyme feed additive on growth performance, nutrient digestibility, and gut microbiome of weanling pigs fed corn-wheat or wheat-barley-based diet.

One-hundred-and-ninety-two weanling pigs (6.7kg body weight) were used to evaluate the impact of a carbohydrases-protease enzyme complex (CPEC) on growth performance, nutrient digestibility, and gut microbiome. Pigs were assigned to one of the four dietary treatments for 42 d according to a 2 × 2 factorial arrangement of diet type (low fiber [LF] or high fiber [HF]) and CPEC supplementation (0 or 170mg/kg diet). The LF diet was prepared as corn-wheat-based diet while the HF diet was wheat-barley-based and contained wheat middlings and canola meal. Each dietary treatment consisted of 12 replicate pens (six replicates per gender) and four pigs per replicate pen. Over the 42-d period, there was no interaction between diet type and CPEC supplementation on growth performance indices of pigs. Dietary addition of CPEC improved (P < 0.05) the body weight of pigs at days 28 and 42 and the gain-to-feed ratio of pigs from days 0 to 14. During the entire experimental period, dietary CPEC supplementation improved (P < 0.05) the average daily gain and gain-to-feed ratio of pigs. There were interactions between diet type and CPEC supplementation on apparent total tract digestibility (ATTD) of dry matter (DM; P < 0.01), gross energy (GE; P < 0.01), and neutral detergent fiber (NDF; P < 0.05) at d 42. Dietary CPEC addition improved (P < 0.05) ATTD of DM, GE, and NDF in the HF diets. At day 43, dietary CPEC addition resulted in improved (P < 0.05) apparent ileal digestibility (AID) of NDF and interactions (P < 0.05) between diet type and CPEC supplementation on AID of DM and crude fiber. Alpha diversity indices including phylogenetic diversity and observed amplicon sequence variants of fecal microbiome increased (P < 0.05) by the addition of CPEC to the HF diets on day 42. An interaction (P < 0.05) between diet type and CPEC addition on Bray-Curtis dissimilarity index and Unweighted UniFrac distances was observed on day 42. In conclusion, CPEC improved weanling pig performance and feed efficiency, especially in wheat-barley diets, while dietary fiber composition had a more significant impact on fecal microbial communities than CPEC administration. The results of this study underscores carbohydrase's potential to boost pig performance without major microbiome changes.

273 Effects of Xylanase Supplementation in Diets with Reduced Metabolizable Energy and Supplemental Fat on Intestinal Health, Mucosa Associated Microbiota and Growth Performance of Nursery Pigs

Abstract This study aimed to investigate the effects of reducing metabolizable energy (ME) below the requirement by reducing supplemental fat on intestinal health and growth performance of nursery pigs. One hundred and ninety-two newly weaned pigs at 7.3 ± 0.6 kg BW were allotted in a RCBD with sex and initial BW as blocks. Pigs were assigned to one of 8 dietary treatments with varying ME levels (3,400, 3,375, 3,350, 3,325, and 3,300 kcal/kg ME) by reducing supplemental fat and increasing xylanase (X0: 0, X40: 1,200, X80: 2,400 and X120: 3,600 XU/kg of feed) in ME deficient diets by 100 kcals/kg. Pigs were fed diets for 35 d in 2 phases (14 d and 21 d, respectively) and growth performance was measured at the end of each phase. Phase 2 diet had titanium dioxide (0.4%) as indigestible external marker to measure ileal digestibility of nutrients. At d 35, a pig representing the median BW within each pen from 3 dietary treatments (ME at 3,400 and 3,300 kcal/kg ME with or without xylanase) were euthanized for sampling jejunal mucosa, jejunal tissue, and ileal digesta to analyze intestinal health parameters, mucosa associated microbiota, and apparent ileal digestibility (AID) of nutrients. Data were analyzed using Mixed procedure of SAS 9.4. Overall, reducing ME level had no effect on growth performance of nursery pigs. However, reducing ME by 100 kcal/kg ME below the requirement increased (P &amp;lt; 0.05) digesta viscosity (1.7 to 2.2 cP) and protein carbonyl (0.18 to 0.40 nmol/mg), tended to change the relative abundance of Prevotellaceae (P = 0.062, 49 to 23%) and Lactobacillaceae (P = 0.086, 7 to 19%), reduced (P &amp;lt; 0.05) villus height (467 to 433 µm) and villus height to crypt depth ratio (1.80 to 1.64) in the jejunum, and reduced (P &amp;lt; 0.05) AID of DM (59.5 to 47.3%), gross energy (59.1 to 43.0%), crude protein (63.4 to 44.6%), and ether extract (67.7 to 55.2%). Xylanase supplementation decreased (P &amp;lt; 0.05) digesta viscosity (2.2 to 1.82 cP) and protein carbonyl (0.40 to 0.17 nmol/mg), increased the relative abundance of Prevotellaceae (20.22 to 61.56%), increased villus height (433 to 462 µm) and villus height to crypt depth ratio (1.64 to 1.99) in the jejunum, and increased (P &amp;lt; 0.05) AID of DM (47.3 to 58.7%), and gross energy (42.9 to 56.0%). In conclusion, reducing ME (100 kcal/kg below the requirement) by reducing supplemental fat (by 2% unit) impaired intestinal health, reducing ability of the pigs to digest feeds whereas xylanase supplementation appeared to mediate some of the negative effects seen by energy reduction by improving intestinal morphology, reducing oxidative damage products, and diversity of the mucosa-associated microbiota.

Effect of increasing dietary fermentable fiber on diet nutrient digestibility and estimation of endogenous phosphorus losses in growing pigs.

Fermentable fiber may increase endogenous losses of phosphorus (EPL) and amino acids (AA), thereby reducing apparent nutrient digestibility. Acacia gum with medium-to-high fermentability and low viscosity was increasingly included in diets to investigate its effect on apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients, gross energy (GE), and standardized total tract digestibility (STTD) of P in growing pigs. A control diet (49% cornstarch; 18% bovine plasma protein) was formulated to measure basal EPL. Three additional diets were formulated to include 2.5%, 5.0%, or 7.5% acacia gum at the expense of cornstarch. Diets contained 16.1% to 17.4% CP and 0.31% to 0.33% total P (DM-basis). The four diets were fed to eight ileal-cannulated barrows (initial BW, 54.6 kg) for four 9 d periods in a double 4 × 4 Latin square. Apparent hindgut fermentation (AHF) was calculated as ATTD minus AID. Feeding increasing acacia gum quadratically affected (P < 0.05) AID of DM, GE, linearly decreased (P < 0.05) ATTD of DM, crude protein (CP), GE, digestible (DE) and predicted net energy (NE) value of diets, and linearly increased (P < 0.001) AHF of DM and GE. Increasing acacia gum did not affect AID and standardized ileal digestibility (SID) of CP and AA. Basal EPL was 377 mg/kg DM intake (DMI) and increasing acacia gum linearly increased (P < 0.05) total tract EPL. Increasing acacia gum linearly decreased (P < 0.05) diet ATTD of P, and STTD of P based on either the calculated EPL or NRC (2012) recommended value (190 mg P/kg DMI). Increasing acacia gum did not affect AID and ATTD of Ca of diets. In conclusion, feeding increasing dietary fermentable, low-viscous acacia gum decreased diet AID and ATTD of DM and GE, but did not affect AID or SID of CP and AA. Increasing acacia gum decreased ATTD of P, which might have been due to increased specific endogenous losses of P in the total tract of growing pigs.

275 Effects of Reduced Metabolizable Energy by Reducing fat Supplementation on Growth Performance and Intestinal Health of Nursery Pigs

Abstract This study aimed to investigate the effects of reducing metabolizable energy (ME) by reducing fat supplementation on growth performance and intestinal health of nursery pigs. Nursery pigs (n = 120; 7.3 ± 0.6 kg BW) were allotted in a randomized complete block design with sex and initial BW as blocks. Pigs were assigned to 5 dietary treatments with decreasing ME levels (3,400, 3,375, 3,350, 3,325, and 3,300 kcal/kg ME). ME content was gradually reduced by reducing fat supplementation (2%). Pigs were fed for 35 d in 2 phases (P1: 14 d and P2: 21 d). Titanium dioxide was added (0.4%) to P2 diets as an indigestible external marker to measure apparent ileal digestibility (AID) of nutrients. At d 35, a pig with median BW of each pen in 2 treatments (3,400 and 3,300 kcal/kg) was euthanized for sampling jejunal mucosa to analyze oxidative stress and immune status. Jejunal digesta was collected to measure viscosity. Ileal digesta was collected to analyze AID of nutrients. Data were analyzed using SAS. Reducing ME level by 3% (100 kcal/kg) had no effect on growth performance. The 3,300 kcal/kg diet reduced (P &amp;lt; 0.05) AID of DM (59.5 to 47.3%), GE (59.1 to 43.0%), CP (63.4 to 44.6%), and EE (67.7 to 55.2%), increased (P &amp;lt; 0.05) digesta viscosity (1.7 to 2.2 cP) and VH:CD (1.64 to 1.80), and decreased (P &amp;lt; 0.05) VH (467 to 433 µm) when compared with 3,400 kcal/kg diet. Additionally, the 3,300 kcal/kg diet increased (P &amp;lt; 0.05) the concentration of protein carbonyl (0.18 to 0.40 nmol/mg) in the jejunal mucosa. In conclusion, reducing ME by reducing fat supplementation by 2% increased the viscosity of jejunal digesta and protein carbonyl in the jejunal mucosa, resulting in decreased villus height and nutrient digestibility, without affecting growth performance.

The effects of xylo-oligosaccharides on regulating growth performance, nutrient utilization, gene expression of tight junctions, nutrient transporters, and cecal short chain fatty acids profile in Eimeria-challenged broiler chickens

A 21-d experiment was conducted to investigate the effects of xylo-oligosaccharides (XOS) on growth performance, nutrient utilization, gene expression of tight junctions, nutrient transporters, and cecal short chain fatty acids (SCFA) profile of broiler chickens challenged with mixed Eimeria spp. Two hundred fifty-two zero-day-old chicks were allocated to 6 treatments in a 3 × 2 factorial arrangement (corn-soybean meal diets supplemented with 0, 0.5, or 1.0 g/kg XOS; with or without Eimeria challenge). Challenged groups were inoculated with a solution containing E. maxima, E. acervulina, and E. tenella oocysts on d 15. During the infection period (d 15 to d 21), there was a significant (P < 0.05) Eimeria × XOS interaction for weight gain (WG). XOS significantly (P < 0.05) increased WG in the unchallenged birds but not in the challenged treatments. There was no significant Eimeria × XOS interaction for N and minerals utilization responses. XOS supplementation at 0.5 g/kg tended to alleviate Eimeria-induced depression in apparent ileal digestibility of DM (P = 0.052). Challenged birds had lower (P < 0.01) AME, AMEn, and total retention of N, Ca, and P. Eimeria upregulated (P < 0.01) gene expression of tight junction proteins claudin-1, junctional adhesion molecule-2, and glucose transporter GLUT1; but downregulated (P < 0.01) the peptide transporter PepT1, amino acid transporters rBAT, CAT2, y+LAT2, and zinc transporter ZnT1. XOS alleviated (P < 0.05) Eimeria-induced claudin-1 upregulation. Eimeria decreased (P < 0.05) cecal saccharolytic SCFA acetate, butyrate, and total SCFA, but increased (P < 0.05) branched chain fatty acids isobutyrate and isovalerate. The supplementation of XOS tended to decrease the concentration of isobutyrate (P = 0.08) and isovalerate (P = 0.062). In conclusion, 0.5 g/kg XOS supplementation alleviated depression in growth performance and nutrient utilization from the Eimeria challenge. In addition, supplemental XOS reversed the gene expression changes of claudin-1, also showed the potentials of alleviating the negative cecal fermentation pattern induced by Eimeria infection.

232 Effects of Yarrowia Lipolytica Supplementation on Growth Performance and Apparent Ileal Digestibility of Diets Fed to Nursery Pigs

Abstract The objective was to evaluate Yarrowia lipolytica (YL) as a lipid supplement fed to nursery pigs for the growth performance and apparent ileal digestibility (AID). Twenty-four pigs weaned at 21 d of age (12 barrows and 12 gilts with initial BW at 7.2 ± 0.6 kg) were allotted to 3 dietary treatments (n = 8) based on the randomized complete block design with sex and BW as blocks. The main effect was the dietary supplementation of YL (0, 1.5, and 3.0%, replacing poultry fat) with nutrients meeting or exceeding the requirements by NRC (2012) and fed to pigs for 21 d based on 2 phases. Feed intake and BW were recorded at d 0, 10, and 21 to calculate ADG, ADFI, and G:F. Fecal scores were recorded at every odd day from d 3 to 19. Pigs were euthanized on d 21 to collect ileal digesta for AID of nutrients in diets. Data were analyzed using Proc Mixed of SAS. There were no differences in growth performance among treatments. Whereas, pigs fed 0 and 1.5% YL had higher (P &amp;lt; 0.05) AID of DM (55.0 and 52.2% to 40.2%, respectively) and GE (62.1 and 60.6% to 49.8%, respectively) than pigs fed 3% YL. There were no differences in AID of DM and GE between the pigs fed 0% and 1.5% YL. In conclusion, 1.5% Yarrowia lipolytica could be supplemented in nursery pig diets reducing 0.8% of poultry fat without affecting growth performance and AID of DM and GE.

Dietary Yeast Cell Wall Improves Growth Performance and Prevents of Diarrhea of Weaned Pigs by Enhancing Gut Health and Anti-Inflammatory Immune Responses

Simple SummaryPost-weaning stress can substantially affect performance of weaned pigs as well as overall pig production, and thus, a practical approach is needed to improve their performance by alleviating the stress that can cause intestinal barrier dysfunction of weaned pigs. There are potential ways to solve the concern in swine production, but dietary yeast cell wall in weaner diets may be one possible solution. The results of the present study suggest that dietary yeast cell wall improves growth performance of weaned pigs by enhancing gut health and provide its potential mechanism.Dietary yeast cell wall products (YCW) are recognized as a feed additive due to multifunctional benefits by the biological response modulators. Thus, this study was conducted to verify a potential advantage of YCW for improving growth performance, nutrient digestibility, immune responses, and intestinal health and microbiota of weaned pigs. A total of 112 weaned pigs (7.99 ± 1.10 kg of body weight; 28 days old) were arbitrarily allocated to two experimental treatments with eight pigs (four barrows and four gilts) per pen and seven replicate pens per treatment in a completely randomized block design (block = BW and sex): (1) a basal diet based on corn and soybean meal (CON) and (2) CON + 0.05% YCW. The experimental period was for 4 weeks. There were no differences in final body weight, average daily feed intake, and gain-to-feed ratio between dietary treatments. In contrast, pigs fed YCW had higher average daily gain (p = 0.088) and apparent ileal digestibility of DM (p < 0.05) and energy (p = 0.052) and lower diarrhea frequency (p = 0.083) than those fed control diet (CON). Pigs fed YCW also had a higher (p < 0.05) ratio between villus height and crypt depth, villus width and area, and goblet cell counts in the duodenum and/or jejunum than those fed CON. Dietary YCW decreased (p < 0.05) serum TNF-α and IL–1β of weaned pigs on day 7 and 14, respectively, compared with CON. Furthermore, pigs fed YCW had higher (p < 0.05) ileal gene expression of claudin family, occludin, MUC1, INF-γ, and IL-6 and lower (p < 0.05) that of TNF-α than those fed CON. Lastly, there were no differences in the relative abundance of bacteria at the phylum level between CON and YCW. However, dietary YCW increased (p < 0.05) the relative abundance of genera Prevotella and Roseburia compared with CON. This study provided that dietary YCW improved growth rate, nutritional digestibility, and intestinal health and modified immune responses and intestinal microbiota of weaned pigs.

Energy and phosphorus evaluation of poultry meal fed to broiler chickens using a regression method

Two experiments were conducted to determine energy (Exp. 1) and P (Exp. 2) utilization in poultry meal (PM) for broiler chickens. A total of 192 birds were allotted to 3 experimental diets in a randomized complete block design with BW as a blocking factor on d 15 and 16 post hatching in Exp. 1 and 2, respectively. Each diet was fed to 8 replicate cages with 8 birds per cage in both experiments. Initial BW of birds in Exp. 1 and 2 were 438 ± 76.9 g and 543 ± 50.2 g, respectively. Three corn-soybean meal-based diets were prepared to contain 0, 80, or 160 g/kg in Exp. 1 and 0, 50, or 100 g/kg in Exp. 2. In Exp. 1, the addition of PM to the reference diet linearly decreased (P < 0.01) the apparent ileal digestibility of DM and gross energy (GE), as well as the apparent total tract utilization (ATTU) of DM, GE, and N in diets; but did not affect the ileal digestible energy, ME, and MEn of diets. The ileal digestible energy, ME, and MEn of PM estimated by the regression method were 4,002, 3,756, and 3,430 kcal/kg DM, respectively, representing 58 to 68% of the GE in PM. In Exp. 2, graded concentration of PM in the reference diet linearly decreased (P < 0.05) ATTU of DM but linearly increased (P < 0.01) ATTU of P and quadratically increased ATTU of Ca in diets. The true ileal digestibility and true total tract utilization of P in PM estimated by the regression method were 77.5 and 79.0%, respectively. In conclusion, these results showed that inclusion of poultry meal in the diets of broiler chickens reduced the digestibility of GE but increased the utilization of P. The regression-estimated energy values and P digestibility of PM in the current studies may be used in diet formulation.

Energy values of Tenebrio molitor larvae meal and tilapia byproduct meal for broiler chickens determined using the regression method

A study was conducted to determine ileal digestible energy (IDE), metabolizable energy (ME), and nitrogen-corrected ME (MEn) of Tenebrio molitor larvae meal and Nile tilapia byproduct meal for broiler chickens using the regression method. A total of 315 slow feathering Cobb 500 male broilers were fed 5 experimental diets with 9 replicate cages of 7 birds each, in a completely randomized design. Broilers were fed a maize-soybean meal reference diet (RD) and 4 test diets (TD) from d 14 to 21 posthatch. The TD consisted of Tenebrio molitor larvae meal and tilapia byproduct meal that partly replaced the energy sources in the reference diet at 100 or 200 g/kg and 75 or 150 g/kg, respectively, such that equal ratios were maintained for all energy containing ingredients across all experimental diets. Excreta samples were collected twice daily from d 19 to 21, and ileal digesta were collected on d 21. Apparent ileal digestibility of DM, N, amino acids as well as metabolizability coefficients of DM, N, and energy were calculated. Addition of Tenebrio molitor larvae meal to the RD linearly increased (P < 0.05) ileal and total tract of DM and N digestibilities as well as IDE, ME, and MEn. For diets with Tenebrio molitor larvae meal substitution, regression equations were IDE = 21.52x – 0.0234, ME = 21.93x – 0.0189, and MEn = 20.62x – 0.0241. Addition of tilapia byproduct meal to the RD linearly decreased (P < 0.05) ileal and total tract coefficients of DM and IDE, ME, and MEn, as well as ileal digestibility of amino acids (P < 0.001). The equations for the tilapia byproduct meal diets were IDE = 12.49x – 0.0264, ME = 14.29x – 0.0152, and MEn = 11.94x – 0.0129. In conclusion, the current study showed that broiler chickens can utilize a considerable amount of energy and amino acids from insect meal or fish meal. The IDE, ME, MEn values (MJ/kg of DM) were 21.52, 21.93 and 20.62 for Tenebrio molitor larvae meal, and 12.49, 14.29 and 11.94 for tilapia byproduct meal, respectively.

156 Influence of viscosity and fiber on nutrient digestibility and intestinal physiology in growing pigs

Abstract Fiber is known for decreasing nutrient utilization in pigs. The addition of fiber alters diet viscosity, but our understanding of the effect of diet viscosity on nutrient digestibility is limited. This knowledge is necessary for improving dietary fiber utilization and when evaluating alternative feed ingredients. Thirty-six T-cannulated barrows (n = 6/treatment; initial BW = 26.5 ± 3.9 kg) were fed either corn-soybean meal (CSBM) basal diets or CSBM with 30% distillers dried grains with solubles as fiber source (CSBM+DDGS). The viscosity of diets were modified by using non-viscous cellulose (CEL), medium-viscosity carboxymethylcellulose (MCMC), or high-viscosity carboxymethylcellulose (HCMC) to assess viscosity effects on nutrient digestibility and intestinal physiology. After 29 d on diets, ileal digesta were collected to determine viscosity and apparent ileal digestibility (AID). Also, intestinal tissue and contents were harvested to determine morphometry, goblet cell quantitation, and digestive enzymatic activity. Data were analyzed using a linear mixed model with treatments as fixed effects and initial BW as a random effect. Results are shown in Table 1. No interactions were observed between viscosity and diets. Inclusion of MCMC and HCMC increased viscosity of supernatant and whole digesta compared with CEL. Increasing diet viscosity decreased AID of DM and CP in pigs fed MCMC and HCMC compared with pigs fed CEL, respectively. The AID of DM and CP were greater in CSBM than CSBM+DDGS. Inclusion of CMC increased crypt depth in the jejunum and goblet cell area in the ileum compared with pigs fed CEL regardless of basal diet fed. Digesta trypsin activity was not different among treatments, but inclusion of CMC increased amylase activity by 43% in jejunal digesta compared with CEL. The addition of DDGS reduced AID; however, viscosity affected intestinal morphology and function, suggesting that viscosity is the main characteristics of fiber affecting nutrient utilization of pigs.

172 Increasing inclusion of fermentable fiber decreases nutrient digestibility in grower pigs

Abstract Fermentable fiber may increase endogenous losses of P and AA, thereby reducing apparent nutrient digestibility. Acacia gum fiber with medium-to-high fermentability and low viscosity was used to investigate its effect on apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients, and standardized total tract digestibility (STTD) of P in grower pigs. A P-free basal diet (49% corn starch; 18% bovine plasma protein) was formulated to measure basal endogenous P losses (EPL). Three diets were formulated to include 2.5, 5.0, or 7.5% acacia gum fiber at the expense of corn starch in the P-free basal diet. Diets contained 16.1–17.4% CP and 0.31–0.33% total P (DM-basis). The 4 diets were fed to 8 ileal-cannulated barrows (initial BW, 54.6 kg) for four 9-d periods in a double 4 × 4 Latin square. Apparent hindgut fermentation (AHF) was ATTD minus AID. Increasing inclusion of acacia gum quadratically decreased (P &amp;lt; 0.01) AID of DM (∆ 11.1%), linearly decreased (P &amp;lt; 0.05) ATTD of DM (∆ 1.7%) CP (∆ 1.2%), and quadratically increased (P &amp;lt; 0.05) AHF of DM (∆ 9.4%). Basal EPL were 391 and 377 mg/kg DM intake (DMI) for ileum and total tract, respectively. Increasing inclusion of fiber linearly increased (P &amp;lt; 0.05) ileal EPL (∆ 184 mg/kg DMI), and tended to linearly increase (P &amp;lt; 0.10) EPL for total tract (∆ 243 mg/kg DMI). Dietary inclusion of acacia gum tended to linearly decrease (P &amp;lt; 0.10) AID of P, but did not affect (P &amp;gt; 0.10) ATTD, or STTD of P. In conclusion, increasing inclusion of fermentable, low viscous acacia gum fiber decreased diet digestibility of DM and ATTD of CP, but did not affect total tract P digestibility, indicating that increasing fermentable fiber did not increase specific endogenous losses of P in the total tract.

Energy values of copra meal and cornstarch for broiler chickens

Two studies were conducted with broiler chickens to determine the ileal digestible energy (IDE), ME, and MEn in copra meal (CM) and cornstarch using the regression method. On day 15 and 16 for experiments 1 and 2, respectively, 192 male birds were individually weighed and allotted into 3 dietary treatments with 8 replicate cages and 8 birds per cage in a randomized complete block design with the BW as a blocking factor in each experiment. Dietary treatments consisted of 3 inclusion levels of test ingredients (i.e., 0, 100, or 200 g/kg) in corn-soybean meal–based diets using CM or cornstarch as test ingredients for experiment 1 or 2, respectively. Titanium dioxide was added as an indigestible marker to determine the ileal digestibility and utilization of energy by the index method. Experiments lasted 5 d, and excreta collection was conducted during the last 3 d of each experiment. At the end of experiments, birds were euthanized by CO2 asphyxiation, and ileal digesta samples were collected. Data were analyzed by the ANOVA using the GLM procedure. In experiment 1, the apparent ileal digestibility (AID) of DM and gross energy (GE) and IDE in test diets linearly decreased (P < 0.05) with substitution of CM in test diets. In experiment 2, there were quadratic increases (P < 0.01) in the AID of DM and GE and IDE in diets as the concentration of cornstarch in test diets increased. In addition, linear increases (P < 0.05) in the apparent total tract utilization of DM, N, and GE and ME and MEn in test diets were observed. The estimates of IDE, ME, and MEn in CM were 2,493, 3,727, and 3,546 kcal/kg DM, respectively, whereas respective values of cornstarch were estimated at 4,181, 3,992, and 3,946 kcal/kg DM, respectively. In conclusion, inclusion of CM in diets may reduce the digestibility of GE, whereas the digestibility and utilization of GE may increase when adding cornstarch into diets for broiler chickens.

Measurement of ileal endogenous energy losses and true ileal digestible energy of cereal grains for broiler chickens

Two experiments were conducted to determine the ileal endogenous energy losses (IEEL) and nitrogen-corrected apparent metabolizable energy (AMEn) and true ileal digestible energy (TIDE) of 4 cereal grains (corn, sorghum, wheat, and barley) for broilers. In experiment 1, a glucose-based purified diet was used to determine the IEEL for correcting the apparent ileal digestible energy (AIDE) values to TIDE. The diet was randomly allocated to 6 replicates (6 birds per replicate) of male broilers and fed from 18 to 21 d after hatch. The jejunal and ileal digesta were collected on day 21. The results showed that glucose absorption continued beyond the jejunum but was complete in the terminal ileum demonstrating that endogenous energy losses can be quantified in the ileal digesta of birds by feeding a glucose-based diet. The IEEL were determined to be 347 ± 29.4 kcal/kg DM intake. In experiment 2, 4 experimental diets with similar inclusion (957 g/kg) of grains were developed to determine the AMEn, AIDE, and TIDE. Titanium dioxide (5.0 g/kg) was added to all diets as an indigestible marker. Each diet was randomly allocated to 6 replicates (8 birds per replicate) and fed from 14 to 21 d after hatch, and the ileal digesta were collected on day 21. The AIDE was corrected to TIDE using the IEEL value determined in experiment 1. The TIDE of corn, sorghum, wheat, and barley were determined to be 3,920, 3,650, 3,138, and 2,885 kcal/kg DM, respectively, and was higher (P < 0.05) than the corresponding AMEn values of 3,439, 3,284, 2,576, and 2,371 kcal/kg DM, respectively. No differences were observed between the AMEn and AIDE. The AMEn:TIDE ratio tended (P = 0.06) to be lower for viscous cereals (wheat and barley) than that for nonviscous cereals (corn and sorghum). The apparent ileal digestibility of DM, nitrogen, and starch was positively correlated (P < 0.001) with TIDE (r = 0.990, 0.703, and 0.705, respectively) and the AMEn (r = 0.873, 0.483, and 0.656, respectively). Further studies are warranted to determine the TIDE of a range of ingredients and to investigate the application of TIDE as a potential available energy system in poultry feed formulations.

Response of broiler chickens in the starter and finisher phases to 3 sources of microbial phytase

A broiler chicken study was conducted for 42 D to evaluate their responses to 3 commercially available microbial phytases. Growth performance, nutrient digestibility, and bone mineralization at days 21 and 42 posthatching were used as parameters of evaluation. The study was a randomized complete block design with 12 treatments, 8 replicate pens, and 25 birds per pen. Treatments included a positive control (PC), a negative control (NC) with crude protein (CP), nonphytate phosphorus (P), and calcium (Ca) reduced by 18, 1.5, and 1.8 g/kg, respectively; the NC + 4 levels of phytase A (250, 500, 750, 1,000 FTU/kg), 3 levels of phytase B (250, 500, 750 FTU/kg), and 3 levels of phytase C (500, 750, 1,000 FTU/kg). Broilers fed the NC diet had reduced (P < 0.05) performance and digestibility measures at days 21 and 42 relative to the PC. All phytase enzymes improved (P < 0.05) BW, gain, feed efficiency, and tibia ash weight and percent. Inclusion of phytase at the highest levels improved (P < 0.05) tibia ash weight by an average of 18.5 and 22% at days 21 and 42, respectively, over the NC. Phytase A linearly improved (P < 0.05) the apparent ileal digestibility (AID) of DM, Ca, P, copper, and sodium at day 21, and the AID of energy, nitrogen, and all amino acid (AA) digestibility at day 42 posthatching. Phytase B linearly (P < 0.05) improved BW gain and feed efficiency of birds at day 21 and quadratically improved (P < 0.05) the AID of nitrogen and all AA in birds at day 42. Supplementation of birds fed the NC with phytase C linearly improved (P < 0.05) the BW gain, feed intake, feed efficiency, and AID of DM, energy, nitrogen, all AA, and all minerals except manganese at day 42. In conclusion, all 3 phytase products improved the growth performance, nutrient and mineral digestibility, and bone mineralization of birds fed diets deficient in nitrogen, Ca, and P similar to or more than birds fed diet adequate in P and CP.

Thermal processing of corn and physical form of broiler diets

This study aimed to assess the effect of preprocessing of corn and of physical form of diets on growth performance, carcass yield, and nutrient digestibility in broilers and also the influence of corn processing on pellet quality. A total of 1,080 male Cobb chicks from 1 to 35 D were evaluated. Birds were distributed according to a completely randomized design in a 3 × 2 factorial arrangement, with 3 types of corn processing (unprocessed, pelleted, or expanded), and 2 diet physical forms (mash or pelleted), totaling 6 treatments and 9 replicates with 20 birds. The data were submitted to ANOVA, and means were compared by Tukey's test (P < 0.05). There was no interaction between the physical form and preprocessing of corn for any of the studied variables (P > 0.05). The use of expanded corn in the diets before pelleting resulted in higher pellet durability index and lower amount of fines (P < 0.05) when compared with unprocessed corn. Broilers fed pelleted diets had higher feed intake (FI) and weight gain (WG; P < 0.001), higher amounts of abdominal fat (P < 0.05), and lower ileal digestible energy (IDE, P = 0.05) than those fed mash. There was no effect of the feed form on nutrient digestibility (P > 0.05). Broilers fed diets with unprocessed corn had higher FI when compared to those fed diets with expanded or pelleted corn (P < 0.001). The use of pelleted corn resulted in lower WG than the other processing methods (P < 0.01). The corn expansion process improved feed conversion ratio and adjusted feed conversion ratio (P < 0.001). Inclusion of expanded corn improved the coefficient of apparent ileal digestibility of DM, CP, starch, and IDE (P < 0.05) in comparison with unprocessed corn. It is concluded that pelleted diets improve broiler performance. The corn expansion can be used to improve physical quality of the diets and broilers growth performance and nutrient digestibility.

Evaluation of dietary supplementation of a novel microbial muramidase on gastrointestinal functionality and growth performance in broiler chickens

This study was conducted to assess the effect of dietary supplementation of Muramidase 007 to broiler chickens on gastrointestinal functionality, evaluating growth performance, apparent ileal digestibility, intestinal histomorphology, vitamin A in plasma and cecal microbiota. A total of 480 one-day male chicks (Ross 308) were distributed in 16 pens allocated in 2 experimental diets: the control diet (CTR) without feed enzymes, coccidiostat or growth promoters, and the experimental diet (MUR): CTR supplemented with 35,000 units (LSU(F))/kg of the Muramidase 007. Digesta and tissue samples were obtained on days 9 and 36 of the study. A lower feed conversion ratio was observed in the MUR treatment. Apparent ileal digestibility of DM, organic matter and energy were improved by Muramidase 007. It was also observed that MUR improved digestibility of total fatty acids, mono-unsaturated fatty acids and poly-unsaturated fatty acids, and content of vitamin A in plasma at day 9 (P < 0.05). Histomorphological analysis of jejunum samples revealed no differences in the villus height or crypt depth; but a higher number of goblet cells and intraepithelial lymphocytes at day 36 with MUR. No differences were observed in plate counts of enterobacteria or Lactobacillus along the gastrointestinal tract, neither on the cecal short-chain fatty acids. An statistical trend was observed for reduction of cecal clostridia at day 9 for MUR. Analysis of cecal microbiota structure by 16S rRNA gene sequencing revealed relevant changes correlated to age. At day 9, broilers receiving MUR showed decreased alpha diversity compared to CTR that was not detected at day 36. Changes in specific taxonomic groups with an increase in Lactobacillus genus were identified. In conclusion, evaluation of the variables in this study indicates that dietary Muramidase 007 contributes to improve feed conversation ratio and gastrointestinal function in broiler chickens. Effects could have been mediated by slight shifts observed in the intestinal microbiota. More studies are guaranteed to fully understand the mechanisms involved.

Interactive effects of dietary fibre and lipid types modulate gastrointestinal flows and apparent digestibility of fatty acids in growing pigs.

A total of eight ileal and caecal cannulated Yorkshire barrows were used to determine the interactions of dietary fibre (DF) and lipid types on apparent digestibility of DM and fatty acids (FA) and FA flows in gastrointestinal segments. Pigs were offered four diets that contained either pectin or cellulose with or without beef tallow or maize oil in two Youden square designs (n 6). Each period lasted 15 d. Faeces, ileal and caecal contents were collected to determine apparent ileal digestibility (AID), apparent caecal digestibility and apparent total tract digestibility (ATTD) of dietary components. The interactions between DF and lipid types influenced (P &lt;0·05) the digestibility of DM and FA flows. The addition of maize oil decreased (P &lt;0·05) AID of DM in pectin diets, and the addition of beef tallow depressed (P &lt;0·001) ATTD of DM in cellulose diets. Dietary supplementation with beef tallow decreased (P &lt;0·05) the AID of FA in pectin-containing diets but had no effects in cellulose-containing diets. Dietary supplementation with beef tallow increased (P &lt;0·05) AID of SFA and PUFA and the flow of ileal oleic, vaccenic, linolenic and eicosadienoic acids and reduced the flow of faecal lauric, docosatetraenoic and docosapentaenoic acids in pectin- and cellulose-containing diets. In conclusion, the interaction between DF type and lipid saturation modulates digestibility of DM and lipids and FA flows but differs for soluble and insoluble fibre sources, SFA and unsaturated fatty acids and varies in different gastrointestinal segments.

Effect of arginine and glutamine supplementation on performance, health and nitrogen and energy balance in growing rabbits

The aim of this work was to study the effect of supplementation with arginine and glutamine and its interaction on growth performance, chemical composition of body and carcass, and digestible nitrogen and energy body and carcass retention efficiency in growing rabbits. A Basal diet (B) was formulated to contain 29.8 g N/kg DM and 313 g aNDFom-cp/kg DM and with an amino acid level enough to meet rabbits post-weaning requirements, and further three diets were obtained by adding to the B diet as-fed basis 4 g arginine/kg (Arg), 4 g glutamine/kg (Gln) and a mixture of 4 g arginine and 4 g glutamine/kg (Arg + Gln). To determine growth performance and mortality (from 25 to 55 d of age), 1223 rabbits were studied in three consecutive fattening periods Moreover, 104 rabbits were chosen to determine their chemical corporal and carcass composition at weaning (25 d of age) and at 55 d of age using the bioelectrical impedance analysis (BIA). Another 96 rabbits were blocked by litter and assigned at random to the experimental diets to determine apparent ileal digestibility of DM, N and amino acids at 35 d of age and 44 of them were used to determine faecal digestibility of DM, N, gross energy and aNDFom-cp from 32 to 35 d of age. All the trials were executed under common Epizootic Rabbit Enteropathy circumstances. Rabbits fed with Gln supplementation from 25 to 35 d of age showed lower mortality during the whole fattening period than those unsupplemented (41.3% vs. 25.6%; P = 0.042). However, supplementation with arginine and glutamine during the whole fattening period did not affect the mortality. Arginine supplementation increased total and digestible nitrogen intake by 10 and 8%, respectively (P < 0.002), without affecting nitrogen and energy retention. Therefore, the retention efficiency of digestible nitrogen and digestible energy decreased by 8 and 7% (P < 0.001), respectively. This led to an increase of urine nitrogen excretion (by 23%; P = 0.030) and energy losses as urine + heat production (P = 0.003).

A new phytase continuously hydrolyzes phytate and improves amino acid digestibility and mineral balance in growing pigs fed phosphorous-deficient diet.

Ten ileal T-cannulated pigs (19.26 ± 1.06 kg) were used to evaluate the effects of a novel phytase on apparent ileal digestibility (AID) of AA and apparent total tract digestibility (ATTD) and hindgut disappearance of DM, GE, CP, crude fiber, NDF, and ADF as well as minerals balance. Pigs were fed in a duplicated 5 × 4 incomplete Latin square design (5 diets with 4 periods). Each period consisted of a 5-d adjustment period followed by a 3-d total collection of feces and urine and then a 2-d collection of ileal digesta. The 5 diets included a P-deficient basal diet (0.43% Ca and 0.38% total P) that was supplemented with 0 (negative control [NC]), 500, 1,000, or 20,000 phytase units (FTU)/kg phytase and a positive control (PC) diet that was P adequate (0.64% Ca and 0.52% total P). The addition of phytase to the NC diet improved ( < 0.05) AID of phytate from 11.1 to 62.8, 70.6, and 90.5% at the inclusion rates of 500, 1,000, and 20,000 FTU/kg, respectively. In general, phytase supplementation at a dose of 20,000 FTU/kg further increased ( < 0.05) AID of Ca, total P, and phytate and reduced ( < 0.05) the ileal phytate concentration compared with diets with 500 or 1,000 FTU/kg phytase. Pigs fed the diet with 20,000 FTU/kg phytase but not diets with 500 and 1,000 FTU/kg phytase showed improved ( < 0.05) ATTD of CP and AID of DM, GE, CP, Leu, Lys, Thr, Val, Asp, and Ser compared with pigs fed the PC or NC diet. However, hindgut disappearance of crude fiber and NDF ( < 0.05) were reduced in pigs fed the diet with 20,000 FTU/kg phytase compared with pigs fed the PC or NC diet. Pigs fed diets with 500 or 1,000 FTU/kg phytase had greater ATTD and retention of Ca and P than pigs fed the NC diet but less compared with pigs fed the diet with 20,000 FTU/kg phytase. Supplementation of 20,000 FTU/kg phytase to the NC diet improved ( < 0.05) digestibility of Na, Mn, and Zn as well as retention (%) of Zn. Increasing phytase supplementation doses from 0 to 1,000 FTU/kg linearly improved ( < 0.05) retention of Mg; meanwhile, digestibility of Mg and Mn and AID of Thr showed a linear increase trend ( = 0.084). In conclusion, supplementation of the novel phytase at doses up to 20,000 FTU/kg hydrolyzed most of the phytate (90%) and consequently further improved mineral and protein utilization.