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Exogenous β-glucanase (BGase) in barley-based feed has been shown to reduce digesta viscosity in chickens, and thereby improve performance. Less well studied is the potential for BGase to convert barley β-glucan into low molecular weight carbohydrates, which might influence digestive tract function and enteric disease. Coccidiosis-vaccinated broiler chickens were fed graded levels of hulless barley (HB) and BGase to determine their effects on β-glucan depolymerization and digestive tract characteristics. Broilers were fed high β-glucan HB (0%, 30% and 60% replacing wheat) and BGase (0%, 0.01% and 0.1%) in a 3 × 3 factorial arrangement. A total of 5,346 broilers were raised in litter floor pens and vaccinated for coccidiosis on d 5. Each treatment was assigned to 1 pen in each of 9 rooms. The significance level was set at P ≤ 0.05. At both 11 and 33 d of broiler ages, peak molecular weight of β-glucan in ileal digesta decreased with increasing BGase for 30% and 60% HB. The maximum molecular weight for the smallest 10% β-glucan molecules (MW-10%) decreased with BGase at both ages for 30% and 60% HB; for birds fed 0% HB, only 0.1% BGase decreased MW-10%. The 0.1% BGase increased caecal short chain fatty acids (SCFA) compared to the 0.01% BGase at d 11 only for the 60% HB. Ileal pH increased with increasing HB and BGase at d 11 and 33. Caecal pH was lower for 0.1% BGase than 0% BGase for 60% HB at d 11. Relative mRNA expression of interleukin 6 (IL-6) and IL-8 in the ileum increased with 0.1% BGase at d 11 and 33, respectively, whereas expression of ileal mucin 2 (MUC2) decreased with 0.1% BGase at d 33. In the caeca, interactions between HB and BGase were significant for monocarboxylate transporter 1 (MCT1) and mucin 5AC (MUC5AC) on d 11, but no treatment effects were found at d 33. In conclusion, BGase depolymerized high molecular weight β-glucan in HB in a dose-dependent manner. Hulless barley and BGase did not increase SCFA concentrations (except for 60% HB with 0.1% BGase at d 11) and caused minor effects on digestive tract histomorphological measurements and relative mRNA gene expression.

ABSRACT1. An experiment was designed to compare the effects of supplementing laying hen diets with phytase and myo-inositol (inositol).2. Five diets were formulated: high balanced protein (HBP - 840 mg of Dlys/hen/day), HBP with inositol (HBP+I - 0.16%), reduced balance protein (RBP - 672 mg of Dlys/hen/day), RBP with inositol (RBP+I - 0.16%) and RBP with phytase (RBP+P - 3000 FTU/kg).3. Laying hen production, inositol concentrations, digestive tract morphology, amino acid digestibility and intestinal inositol transporters transcript abundance were evaluated. Data were analysed with a one-way ANOVA in SAS 9.4. Contrasts were used to assess the effect of protein, inositol, phytase and phytase vs. inositol. Differences were accepted when P ≤ 0.05.4. No effect on hen-day egg production or feed efficiency was found. However, feed intake and the incidence of abnormally shaped eggs were 0.77 g/h/d and 0.17% higher, respectively, in inositol treatments. Inositol decreased egg specific gravity from 1.088 to 1.0865.5. Inositol concentration in egg yolk was similar among HBP+I, RBP+I and RBP+P, and higher than for the HBP and RBP diet groups. Both gizzard and ileal digesta were enriched in inositol in all supplemented treatments, and phytase supplementation decreased the level of IP5 and IP6 in the gizzard and ileum. Generally, neither phytase or inositol affected amino acid digestibility.6. Inositol increased transcript abundance of alkaline phosphatase in the ileum, while phytase upregulated duodenal alkaline phosphatase and SMIT1, jejunal SMIT2 and reduced ileal HMIT and SMIT1 abundance.7. In conclusion, no effect of phytase or inositol was found for laying hen production performance or amino acid digestibility, but egg quality was reduced by inositol supplementation. Inositol concentration in egg yolk was similar among supplemented treatments.

Diet β-glucanase (BGase) depolymerizes viscous β-glucan into lower molecular weight carbohydrates, which might act as a prebiotic in chickens exposed to enteric disease. Coccidiosis-challenged broiler chickens were fed graded levels of hulless barley (HB) and BGase to determine their effects on growth performance. Broilers were fed high β-glucan HB (CDC Fibar; 0, 30, and 60% replacing wheat) and BGase (Econase GT 200P; 0, 0.01, and 0.1%) in a 3 × 3 factorial arrangement. A total of 5,346 broilers were raised in litter floor pens and vaccinated for coccidiosis in feed and water on day 5. Each treatment was assigned to 1 pen (66 birds) in each of 9 rooms. Statistical significance was set at P ≤ 0.05. Overall, HB decreased body weight gain (BWG) and increased feed: gain ratio (F:G) of broilers. From day 0 to 11, BGase did not affect BWG and F:G, at the 0 and 30% HB. However, at 60% HB, the 0.01% BGase improved them, and the 0.1% BGase had no effect on BWG and increased F:G. For the day 22 to 32 and 0 to 32 periods, BGase did not affect BWG for 0 and 30% HB levels, but for the 60% HB, both BGase levels increased gain. The 0.1% level of BGase resulted in the lowest F:G for all HB levels, with the degree of response increasing with HB. No interaction was found for ileal digesta viscosity at day 11; the level of HB did not affect viscosity, but both levels of BGase decreased viscosity. At day 33, BGase did not affect viscosity at 0 and 30% HB levels, but viscosity was lowered for the 0.1% BGase treatment at the 60% HB level. In conclusion, HB reduced broiler performance, and BGase alleviated most but not all the effects. In young birds fed 60% HB, 0.1% BGase did not impact BWG and increased F:G.

Exogenous β-glucanase (BGase) improves nutrient digestibility and production performance in laying hens fed barley-based diets, but the effect of enzyme and the dosage on β-glucan depolymerization and fermentation in the gastrointestinal tract is poorly understood. The objectives of the study were to determine the effects of hulless barley (HB) and BGase levels on digestive tract β-glucan depolymerization and fermentation in laying hens. A total of 108 Lohman-LSL Lite hens were housed in cages and fed 2 levels of HB (CDC Fibar; 0 and 73%) by substituting wheat in the diet and graded levels of BGase (Econase GT 200 P from ABVista; 0, 0.01 and 0.1% - 0, 20,000, and 200,000 BU/kg) in a 2 × 3 factorial arrangement. Birds were fed experimental diets for 8 weeks, starting at 35 wk of age. Digestive tract samples were collected at the end of the experiment. Statistical significance was set at P ≤ 0.05. Beta-glucan peak molecular weight was lower with the 0.1 compared to both 0 and 0.01% BGase levels, whereas weight average molecular weight was lower with the 0.1 compared to 0% BGase for 73% HB. The maximum molecular weight for the smallest 10% β-glucan molecules decreased with the increasing BGase. Overall, β-glucan molecular weight in the ileum was higher when the birds were given 73 in comparison to 0% HB diets. Total and major short chain fatty acids (SCFA) in the ileum were lower with 0.1 and 0.01 (except propionic acid) compared to 0% BGase in the birds fed 73% HB, but not 0% HB. Interactions between the main effects were found for the cecal acetic and isobutyric acids. In conclusion, exogenous BGase depolymerized high molecular weight β-glucan in HB and wheat. The effects of HB and BGase on carbohydrate fermentation were not apparent, although it appears ileal SCFA concentrations were lower with increasing levels of BGase.

Indigestible dietary protein fermentation products have been suggested to negatively influence broiler performance due to their impact on health and digestive tract morphology. This study evaluated the digestive tract morphology and caecal protein fermentation metabolites of broiler fed 3 dietary protein levels (24%, 26% and 28%) with low or high indigestible protein (LIP, HIP). Two completely randomized 3 × 2 factorial trials were conducted with protein level (PL) and indigestible protein (IDP) as the main factors. In both trials, birds received six diets (24-LIP, 24-HIP, 26-LIP, 26-HIP, 28-LIP and 28 HIP) formulated with no medication. On day 5, trial 1 birds were vaccinated with Coccivac-B52, while trial 2 received no vaccine. Tissue and caecal samples were collected and caecal contents analysed for fermentation metabolites. Differences were considered significant when p ≤ .05. The LIP treatment caecal content in trial 1 at 14 days had greater histamine, agmatine and cadaverine levels, while HIP diets resulted in increased serotonin, tryptamine and spermidine. Histamine, serotonin and tryptamine at day 28 were not affected by IDP, and ammonia was not affected by treatments at day 14 or day 28. At day 14, HIP birds had lower total short-chain fatty acids, higher caecal pH and heavier pancreas, proventriculus, gizzard, jejunum and ileum weights. The same effects of IDP found in trial 1 were observed for histamine, agmatine, cadaverine, serotonin, tryptamine and spermidine at day 21 in trial 2. Trial 2 had a PL-by-IDP interaction influencing tyramine, spermidine (28-LIP > 24-LIP) and spermine with values increasing with PL for LIP diets and remaining constant for HIP diets. An interaction between PL and IDP was found for ammonia level and was similar to interactions for biogenic amines. In conclusion, dietary PL and IDP influence broiler caecal protein fermentation metabolites and those effects varied with coccidiosis vaccination and rearing environment.

The effect of nutrition during the early life of turkey poults has a long-lasting impact on bird performance. This study assessed the digestibility of 5 high protein feed ingredients (soybean meal [SBM], corn gluten meal [CGM], canola protein concentrate [CPC], fish meal [FM], and porcine meal [PCM]) in broiler chickens, as well as their use in turkey pre-starter diets fed to 21 d of age. The first experiment (5 × 2 factorial arrangement) determined nitrogen corrected apparent metabolizable energy (AMEn) and apparent ileal amino acid digestibility (AIAAD) of each ingredient in broiler chickens at 5 and 21 d of age, using 6 replications of 30 and 8 chicks, respectively. In the second experiment (completely randomized design), 4 replication pens, containing 23 d-old poults, were randomly assigned to one of 5 dietary treatments. The diets were formulated based on the AMEn and AIAAD values derived in the first experiment, and consisted of a high SBM control diet, and 4 additional diets with either CPC, FM, PCM or CGM replacing 25% of the protein supplied by SBM in the control diet. Statistical analysis was completed using Proc Mixed in SAS 9.3. Planned contrasts were used to compare treatments in the second experiment. Trends were identified at P

High dietary protein and the use of poorly digested protein sources have been suggested to negatively impact broiler health, possibly because of protein fermentation in the distal intestinal tract. The effect of dietary protein levels with low or high indigestible protein fractions (LIP or HIP) on male and female broiler performance were evaluated. The trial was completely randomized with a 2 × 3 × 2 factorial arrangement, where gender, dietary protein levels (24, 26, and 28%), and dietary protein digestible fractions were the main factors. Ross 308 male (1944) and female (2232) were allocated to 72 pens with 54 males or 62 females per pen. Six grower diets 24-LIP, 24-HIP, 26-LIP, 26-HIP, 28-LIP, and 28-HIP were fed from 0 to 32 D of age. Birds were vaccinated with Coccivac-B52 on day 5, and feed intake and BW were recorded on 0, 12, 22, and 32 D. On day 32, 24 birds per treatment were processed for meat yield. Males were heavier than females at all post-hatch ages and the LIP birds were heavier than their HIP counterparts on 32 D. On day 22, birds fed 24 and 26% CP were heavier than those fed 28% CP. Birds fed the 28-LIP diet consumed less total feed than their 24 and 26-LIP equivalents. Birds fed 24% CP had the highest total feed to gain ratio, whereas LIP fed birds had a lower total feed to gain than those fed HIP diets. LIP diets resulted in higher total mortality than the HIP diets. Carcass yield was higher for females than males, increased with CP level, and was lower in HIP than LIP birds. An interaction between CP level and protein digestibility resulted in the 26 and 28-LIP having higher breast yield than all other diets. In conclusion, broiler growth performance and meat yield were affected by dietary indigestible protein alone or in combination with gender and dietary CP level.

Infrared beak treatment (IRBT) results in a change in beak shape; however, it is unclear what effect variations in post-treatment beak shape have on young pullets. Additionally, the impact of sloughing of the treated beak tissue is not fully understood. Two experiments were conducted to determine the effects of beak tissue sloughing and post-treatment beak shape on the productivity of infrared beak-treated Lohmann Brown (LB) and Lohmann LSL-Lite (LW) pullets and hens. Birds were treated on day of hatch and IRBT equipment settings were adjusted to create 4 specific beak shapes: shovel (SHV), step (STP), standard (STAN), and an untreated sham control (C). Experiment 1 pullets (n = 160) were housed in cages from 1 to 29 d of age and had access to water through chick founts or 360° nipple drinkers (2 replicate cages per treatment). Data collected included body weight (BW), feed intake (FI), feed efficiency (FE), and water disappearance (WD). Experiment 2 pullets (n = 640) were housed in floor pens from 1 d to 18 wk of age (2 replicate pens per treatment) then conventional cages during the laying period (6 replicate cages per treatment). Data collected included BW, FI, egg production, and egg quality. Data were analyzed using PROC MIXED (SAS® 9.4) and differences were significant when P ≤ 0.05. During early life, the IRBT treatments and sloughing had minor effects on FI, FE, and BW. At 4 wk of age, STAN pullets were lighter than C pullets; however, differences were no longer apparent after this age. Pullets with STP or STAN beak shapes had lower WD than C pullets when allowed access to water via nipple drinkers but this did not result in reduced growth. Throughout the laying period, SHV hens laid more saleable eggs than C hens, with no other effects on production. Overall, variations in beak shape and sloughing of the beak tissue had minimal impacts on the productivity of LW and LB pullets and hens.

The rate and extent of protein digestion are relevant to broiler performance and health, but information is lacking on the rate of digestion and the characteristics of the undigested fraction for common protein feed ingredients. Therefore, this study evaluated the digestion kinetics and the distal ileum (DI) digesta protein characteristics of protein meals fed to broiler chickens. Using a completely randomized design, 360 male broilers at 14 D of age were assigned to 60 battery cages and fed semi-purified diets composed of wheat starch (N-free) or wheat starch with either corn distillers dried grains with solubles (CDDGS), corn gluten meal, meat and bone meal, soybean meal, fish meal (FM), porcine meal (PCM), canola meal, blood meal (BM), or feather meal. At day 21, the protein digestion kinetics and total and soluble protein of the DI content were determined. Differences were considered significant when P ≤ 0.05. Protein source affected the extent of amino acid (AA) and CP digestibility at the DI. The results demonstrated differences in digesta mean retention time (MRT) and the rate of digestion of AA and CP among protein sources. FM had the shortest MRT of 46 min, whereas CDDGS had the longest at 142 min. Both FM and PCM had the highest digestion rates for most of the AA evaluated among the protein sources, whereas CDDGS had the lowest. In turn, the total and soluble CP in the distal ileal contents ranged from 54 to 1466 mg and 6 to 347 mg, respectively. In conclusion, dietary protein source influences the amount and solubility of the undigested protein in the DI and the digestion kinetics of AA and CP along the small intestine of broilers. These parameters may contribute to the effects of protein source on muscle deposition and could influence the impact protein sources may have on gut health through protein fermentation.

Stocking density (SD) of turkey toms (n = 2,868 Nicholas Select) was evaluated in 2 16-wk trials. Poults were randomly allocated to 1 of 8 independently ventilated rooms (6.71 × 10.06 m) for each trial, to reach a final target SD of 30, 40, 50, or 60 kg/m2. Air quality was monitored (carbon dioxide and ammonia) throughout the trial, and ventilation was adjusted to balance these parameters across all rooms. Within each trial, body weight and feed consumption were recorded (0, 4, 8, 12, and 16 wk of age). Body weight gain and mortality-corrected feed-to-gain ratio (F: Gm) were calculated for each 4-wk interval. Uniformity was assessed at 12 and 16 wk of age (20 birds per replicate). Mortality and culled birds were recorded daily and necropsied to determine cause of death or illness. Room temperature was recorded hourly, and litter moisture and temperature (trial 2) were evaluated weekly from 12 to 16 wk. A 1-way ANOVA was performed to evaluate the effects of SD on room temperature. Regression analyses were performed to determine the relationship between SD and all other measured variables (linear, Proc Reg; quadratic, Proc RSReg in SAS 9.4). Differences were considered significant when P ≤ 0.05. Body weight decreased as SD increased at 12 (quadratic) and 16 wk (linear). Body weight gain decreased in the last 4 wk (12 to 16, linear) and over the course of the trial (0 to 12, quadratic; 0 to 16, linear) as SD increased. Feed consumption demonstrated a linear relationship with increasing SD, increasing from week 4 to 8 and decreasing from week 12 to 16. The F: Gm ratio increased linearly with increasing SD for all time periods beginning at week 4. Flock uniformity and total percent mortality were unaffected by SD. Litter moisture demonstrated a quadratic effect and litter temperature increased (quadratic) as SD increased. Overall, increasing SD negatively impacted aspects of bird performance, including body weight, body weight gain, and feed efficiency. Feed consumption was negatively impacted later in production (week 12 to 16). Finally, overall mortality and uniformity were not affected.

Ross 308 broilers were observed at 2 ages to quantify how duration of darkness affects behavior and alters the gastrointestinal tract (GIT, segment and content weights) over 24 h. Four treatments provided 1 (1D), 4 (4D), 7 (7D), or 10 (10D) h of darkness. Birds (n = 4000) were housed in 8 rooms with 8 pens per room (2 replications per treatment and 4 replications per gender per room). The GIT data were collected on day 27 to 28 (6 males per treatment, euthanized at 2 h intervals for 24 h) and expressed as a percentage of body weight. Data were analyzed as a completely randomized design, with treatment nested within room. Production data were analyzed as a 4 (dark) x 2 (gender) factorial arrangement and GIT data as a 4 (dark) x 12 (time) factorial arrangement. Regression analyses established relationships between darkness and dependent variables. At 31 d, regression analyses showed no effect on body weight. The highest feed consumption was observed under 4D. Mortality was lowest under 10D. Birds on 10D were the most feed efficient and had the heaviest crops. Crop content interacted with time of day, with peaks prior to dark under 4D, 7D, and 10D. Empty gizzard weight increased linearly as dark increased (P.01). Behavior was examined as a 4 (dark) x 2 (age) x 2 (gender) factorial arrangement of treatments. Five birds per gender per room were focally observed for 24 h. Dark data were examined using regression analyses and an analysis of variance assessed age and gender data. As dark increased, feeding bout frequency increased and total time spent at the feeder decreased linearly (P = 0.01 and P.01, respectively). As birds aged, feeding frequency decreased and feed bout length increased. Males visited the feeder more frequently. Birds anticipated dark periods4 h and increased feeding activity prior to dark. Broilers adapt their feeding behavior in response to dark exposure, which alters GIT segment and content weight and likely feed passage rate.

Feeding behaviour can be affected by diet composition as a result of diet density, the rate and extent of ingredient digestion and the activation of nutrient sensing mechanisms. It was hypothezised that the presence of starch in the distal small intestine would activate the ileal brake, thereby increasing satiety, and changing feeding behaviour. Two semi-purified starch sources with differing in-vitro digestibility, wheat (WS, rapidly digested), and pea (PS, slowly digested), were used in four diets containing equal amounts of starch, but differing in WS/PS ratios (100/0, 80/20, 60/40, 0/100). Diets were fed to Ross 308 male (944) and female (1056) broilers housed in 32 litter floor pens from 0 to 28 d. Similar diets were fed to 192 laying hens from 26 to 46 weeks of age, housed in 16 experimental units, comprised of two conventional cages each. Video recordings (24 h) were taken at 27–28 d from four individually marked broilers per pen, and at 46 weeks of age from two hens per experimental unit. Focal observations were used to record the initiation and end of every feeding (broilers, hens) and drinking bout (broilers) over 24 h to calculate number of bouts, bout length, time between bouts, total time during the photo and scotoperiod, and time until first night bout. Data were analyzed as a four (diet) by two (gender) factorial arrangement (broiler) or one-way ANOVA (laying hen) using the SAS 9.4 GLIMMIX procedure. No interactions were found. Diet affected broiler number of visits to the feeder (P = 0.034), as well as time between feeding bouts (P = 0.031) and total feeding time (P = 0.028), but changes appeared random and did not support a satiety hypothesis. Males had more visits to the feeder (P

This paper presents digestion kinetics data for commonly available high protein feed ingredients using an in vitro model that mimics the gastric and intestinal phases of chickens. Soybean meal (SBM), corn gluten meal (CGM), corn distiller dried grains with solubles (CDDGS), porcine meal (PCM), fish meal (FM), canola meal (CM), meat and bone meal (MBM), feather meal (FEM) and blood meal (BM) were digested in 6 replicate tubes. Meal sample equivalent to 500 mg crude protein (CP) was digested with 28,260 units of pepsin in 50 mL polyethylene centrifuge tubes for 30 min in a shaking water bath at 41 °C. After gastric digestion, tube pH was adjusted to 7 ± 0.5 using NaOH. A 9.5 mL volume of sodium acetate buffer (pH 12.5) and 6.5 mL pancreatin (trypsin = 30,667 BAEE units/mL, chymotrypsin = 2157 BTEE units/mL and elastase = 7 units/mL), and 3 glass marbles were placed in the tube which were incubated for 180 min at 41 °C in a water bath. Tubes were sampled at 0, 15, 30, 45, 60, 90, 120, 150 and 180 min of the intestinal phase and digestibility (DIG) determined calorimetrically with ninhydrin reagent per time point. The DIG data were fitted to the model P = A + B (1- e -kd*t ) using the PROC NLIN procedure of SAS 9.4 and all constants were analyzed using the PROC Mix procedure. The modeled predicted (P) CP DIG (%) of the meals were SBM 87, FM 88, PCM 79, CGM 73, MBM 56, CM 82, BM 47, FEM 48 and CDDGS 58. Estimated fractional digestion rate (kd) values for BM and FEM were 0.062 and 0.054, respectively, while MBM, CGM, FM, PCM, CM, SBM and CDDGS were 0.046, 0.041, 0.040, 0.038, 0.035, 0.027 and 0.017, respectively. In conclusion, protein digestion of high protein meals was determined with an in vitro technique, which provided the opportunity to categorize the ingredients based on their digestion kinetics as well as extent of digestion.

With growing cross-disciplinary collaboration among researchers, it is increasingly important to record detailed methodology to prevent the repetition of preliminary experiments. The purpose of this paper is to explain the development of a coccidiosis challenge model for the investigation of dietary interventions to coccidiosis in broiler chickens. The objectives are to select a dose of mixed species coccidial vaccine and evaluate the suitability (ability to produce a consistent, marked change) of selected response variables important to nutritional studies at different times postinfection (PI). Coccivac-B and Coccivac-B52 (Merck Animal Health) were evaluated as the source of coccidia in three trials. Trials 1 and 2 were randomized complete block designs with four doses (0, 10, 20, or 30 times (×) label dose) of Coccivac-B administered to 12 replicate cages of six birds by repeater pipette (Trial 1) or gavaging needle (Trial 2). Trial 3 used a completely randomized design with 0× or 30× label dose of Coccivac-B52 administered by gavaging needle to six replicate cages of six birds. Birds were gavaged at 15 days of age, and response criteria were evaluated 7 days PI in all trials and again at 10 days PI in Trials 1 and 2. All means are reported in order of increasing coccidia dose with significance accepted at P ≤ 0.05. Broiler performance was not affected by coccidia in Trials 1 or 3 but grew poorer with increasing dose from 0 to 7 days PI in Trial 2 (body weight gain, 465, 421, 388, 365 g; feed to gain, 1.37, 1.47, 1.52, 1.58). As coccidia dose increased, nitrogen corrected apparent metabolizable energy decreased (Trial 1, 3387, 3318, 3267, 3170 kcal kg–1; Trial 2, 3358, 2535, 2422, 2309 kcal kg–1; Trial 3, not measured), while relative weight, length, and content for intestinal sections increased (Trials 1through 3). Gross lesion (duodenum, jejunum/ileum, ceca) and oocyst count scores (jejunum/ileum, ceca) increased with dose; however, gross scoring often suggested infection in unchallenged birds, a finding unsupported by oocyst count scores. At 7 days PI there was no correlation between midgut gross lesion score and midgut oocyst count score (r = 0.06, P = 0.705), but cecal scores were weakly correlated (r = 0.55, P < 0.001). Administering coccidia via repeater pipette (Trial 1) resulted in respiratory distress in some birds, while use of the gavaging needle (Trials 2 and 3) successfully induced intestinal damage in chickens without resulting in coccidia related mortality. Thirty times the label dose at 7 days PI resulted in the greatest number of response variables that produced a consistent, marked change. Therefore, consideration should be given to these conditions when designing future coccidiosis challenge models using vaccines as a source of coccidia.

The reduced use of antibiotics in poultry feed has led to the investigation of alternatives to antibiotics, and one such substitution is fermentable carbohydrates. Exogenous β-glucanase (BGase) is commonly used in poultry fed barley-based diets to reduce digesta viscosity. The effects of hulless barley (HB) and BGase levels on ileal digesta soluble β-glucan molecular weight, digestive tract characteristics, and performance of broiler chickens were determined. A total of 360 day-old broilers were housed in battery cages (4 birds per cage) and fed graded levels of high β-glucan HB (CDC Fibar; 0, 30, and 60% replacing wheat) and BGase (Econase GT 200 P; 0, 0.01, and 0.1%) in a 3 × 3 factorial arrangement. Beta-glucan peak molecular weight in the ileal digesta was lower with 30 and 60 than 0% HB, whereas the peak decreased with increasing BGase. The weight average molecular weight was lower at 0.1 than 0% BGase in wheat diets, whereas in HB diets, it was lower at 0.01 and 0.1 than 0% BGase. The maximum molecular weight was lower with 0.01 and 0.1 than 0% BGase regardless of the HB level. The maximum molecular weight was lower with HB than wheat at 0 or 0.01% BGase. Overall, empty weights and lengths of digestive tract sections increased with increasing HB, but there was no BGase effect. Hulless barley decreased the duodenum and jejunum contents, whereas increasing the gizzard (diets with BGase), ileum, and colon contents. The jejunum and small intestine contents decreased with increasing BGase. Ileal and colon pH increased with increasing HB, but there was no BGase effect. Treatment effects were minor on short-chain fatty acids levels and performance. In conclusion, exogenous BGase depolymerized the ileal digesta soluble β-glucan in broiler chickens in a dose-dependent manner. Overall, feed efficiency was impaired by increasing HB levels. However, HB and BGase did not affect carbohydrate fermentation in the ileum and ceca, although BGase decreased ileal viscosity and improved feed efficiency at the 0.1% dietary level.

Limited use of medication in poultry feed led to the investigation of exogenous enzymes as antibiotic alternatives for controlling enteric disease. The objective of this study was to evaluate the effects of diet β-glucanase (BGase) and medication on β-glucan depolymerization, digestive tract characteristics, and performance of broilers. Broilers were fed hulless barley (HB) based diets with BGase (Econase GT 200P from AB Vista; 0 and 0.1%) and medication (Bacitracin and Salinomycin Na; with and without) arranged as a 2 × 2 factorial. In Experiment 1, 160 broilers were housed in cages from d 0 to 28. Each treatment was assigned to 10 cages. In Experiment 2, broilers (2376) were housed in floor pens and challenged with a coccidiosis vaccine on d 5. Each treatment was assigned to one floor pen in each of nine rooms. In Experiment 1, the soluble β-glucan weight average molecular weight (Mw) in the ileal digesta was lower with medication in the 0% BGase treatments. Peak molecular weight (Mp) and Mw were lower with BGase regardless of medication. The maximum molecular weight for the smallest 10% β-glucan (MW-10%) was lower with BGase. In Experiment 2, Mp was lower with medication in 0% BGase treatments. Beta-glucanase resulted in lower Mp regardless of medication, and the degree of response was lower with medication. The MW-10% was lower with BGase despite antibiotic addition. Body weight gain (BWG) and feed efficiency were higher with medication regardless of BGase use through-out the trial (except d 11-22 feed efficiency). Beta-glucanase resulted in higher BWG after d 11, and lower and higher feed efficiency before and after d 11, respectively, in unmedicated treatments. In conclusion, BGase and medication caused the depolymerization of soluble ileal β-glucan. Beta-glucanase appeared as a partial replacement for diet medication to increase coccidiosis challenged broiler performance.

Ideally balanced dietary protein is critical for laying hen egg production and feed efficiency, but also affects other important characteristics. This research was designed to study the nonegg production and feed intake response of Lohmann-LSL Lite hens to 550, 625, 700, 775, and 850 mg d−1 of amino acid balanced digestible lysine (Dlys) from 27 to 66 wk of age. Data collection included hen weight (HW), feather scoring, tissue weights, egg specific gravity, egg component weights, and excreta nitrogen (N) content. The experiment was a completely randomized design and level of significance was fixed at P ≤ 0.05. Hen weight (quadratic, Q), pectoralis muscle (absolute, % – Q), and abdominal fat (absolute – linear, L; % – Q) increased with increasing Dlys intake. Although gastrointestinal segment weights and lengths were affected by Dlys intake, interpretation of results was confounded by other aspects of diet composition. Hen feather score (L) and excreta N content (Q) increased, and egg shell quality (L) decreased with increasing Dlys intake. Absolute egg component weights increased with Dlys intake, but effects on proportional weights were Q and relatively minor. In conclusion, balanced Dlys intake affected a variety of practical nonproduction characteristics in laying hens.

It is difficult to obtain in vivo digestion kinetics data of high protein ingredients using chickens. Collecting kinetics data requires repeated sampling of digesta from the small intestine during the digestion process, which is not easily accomplished due to the anatomical structure of chicken digestive tract. An in vitro technique is proposed for measuring the digestion kinetics of protein sources fed to chickens. The method has a 30 min gastric and 3 h intestinal phase. Five hundred milligram crude protein (CP) equivalent of each meal sample (CP = % N × 6.25) was digested with pepsin (28,260 units) in 50 mL polyethylene centrifuge tubes for 30 min in a shaking water bath (150 strokes/min; 30 mm stroke length) at 41 °C. The 6.5 mL pancreatin was selected as the enzyme concentration for the intestinal phase, during which time 500 μL aliquots were collected at 0, 15, 30, 45, 60, 90, 120, 150, 180 and 240 min. Samples were diluted 1:820 with HCl and sodium acetate buffer, and then mixed with ninhydrin reagent (2:1) at 100 ± 2 °C for 15 min and spectrometric readings taken at 568 nm. To validate the assay, 5 replications of soybean meal (SBM), corn gluten meal (CGM), corn distillers dried grains with solubles (CDDGS), porcine meal (PCM), fish meal (FM) and casein (CA) were digested. The digestion data were modeled with PROC NLIN procedure, and the intra coefficient of variation (CV) assessed using PROC MEANS of SAS 9.4. The digestion values at 180 min were SBM 95 ± 4, FM 93 ± 3, PCM 68 ± 4, CGM 82 ± 3 and CDDGS 70 ± 2. Intra CV for SBM, CGM, CDDGS, PCM and FM were 5%, 5%, 12%, 10% and 2%, respectively. The estimated fractional digestion rates for SBM, CGM, CDDGS, FM and PCM were 0.023, 0.013, 0.009, 0.024 and 0.013, respectively. In conclusion, the proposed in vitro technique estimated the rate and extent of the digestion of CP for the meals with low intra CV. Keywords: Protein digestion rate, Soybean meal, Corn gluten meal, Corn distillers dried grains with solubles, Fish meal, Porcine meal

Laying hens continue to improve in egg production (EP) and feed efficiency (FE), and therefore, it is relevant to re-examine their digestible balanced protein (BP) requirements. From 27 to 66 wk of age, hens (Lohmann-LSL Lite) were fed diets designed to provide 550, 625, 700, 775, or 850 mg hen−1 d−1 of amino acid balanced digestible lysine (Dlys). Response criteria included EP, egg weight (EW), feed intake (FI), mortality, egg mass (EM), egg size classifications, FE (kg feed kg−1 EM), and lysine efficiency (LE; mg Dlys g−1 EM). The experiment was a completely randomized design, and data were analyzed using regression analysis. Differences were considered significant if P ≤ 0.05. Hen-day (HD) EP, EW, EM, FI, and LE increased and FE and mortality decreased in a quadratic fashion with increasing Dlys intake, while the proportion of cracked eggs increased linearly. Egg size classifications increased linearly (jumbo, extra-large) and quadratically (large) or decreased in a quadratic manner (medium, small) with increasing Dlys intake. Maximum HDEP, EW, and EM, and minimum FE were achieved at 769, 903, 836, and 839 mg hen−1 d−1 intake of Dlys, respectively. In conclusion, the digestible BP requirement of laying hens varies with response criteria.

The objective of the study was to measure the effect of wheat market class and cultivar on starch digestibility using an in vitro model that mimics the chicken digestive tract and relate it to grain characteristics. The study evaluated 18 wheat cultivars from eight western Canadian wheat classes and, each cultivar was replicated four times. Samples were subjected to gastric and small intestine (SI) digestion phases and each sample was assayed in triplicate; glucose release was measured in SI phase. Starch granule distribution, amylose, total starch, crude protein (CP), ash, and non-starch polysaccharides (NSP) were analyzed in all wheat samples. Small intestinal phase times of 15, 60, and 120 min were chosen to approximate digestion in the terminal duodenum, jejunum, and ileum. Starch digestibility of wheat classes ranged as follows: 15 min — 33.1% to 49.1%, 60 min — 80.2% to 93.3%, and 120 min — 92.4% to 97.6%. Starch digestibility positively correlated with CP, ash, NSP, and proportion of large granules, whereas it negatively correlated with total starch, and proportion of small and medium granules. In conclusion, market class and cultivar of western Canadian wheat affects both rate and extent of starch digestibility and it is related to various grain characteristics.

SUMMARY Salmonellosis is a significant public health risk and is often associated with the consumption of poultry products. Colonization of poultry by Salmonella may be affected by dietary ingredients. The objective of the study was to evaluate the effects of hulless barley (HB) and β-glucanase (BGase) on Salmonella colonization in broiler chickens. Day-old broilers (200) were placed in battery cages and fed diets with and without high β-glucan HB (CDC Fibar; 0 and 60%) and BGase (Econase GT 200 P from ABVista; 0 and 0.1%) in a 2 × 2 factorial arrangement. Each treatment was assigned to 10 cages. All the birds were orally challenged with Salmonella Enteritidis LS101 strain at d 21. Broilers were infected with Salmonella Infantis before the S. Enteritidis challenge, and feeding HB decreased Salmonella positive cloacal swabs (%). HB decreased the percentage of birds positive for Salmonella in the spleen at pre-challenge and d 1 post-challenge, whereas increased the percentage positive for the spleen at d 4 post-challenge. BGase did not affect Salmonella colonization and translocation.

Energy homeostasis is of fundamental importance to animal well-being as well as in the feeding of species like chickens. Optimizing the balance between energy intake and expenditures is required for efficient, highly productive flocks, and understanding its relationship to production characteristics including energy and feed intake is fundamental to the formulation of chicken diets and levels of other dietary nutrients. A historical perspective on this relationship is that chickens alter feed intake to maintain energy intake when diets contain variable dietary energy. In turn levels of other nutrients, and in particular amino acids, should be adjusted in accordance. However, control of feed intake is complex and even if this perspective were correct, multiple factors can compromise the appropriate adjustment in feed intake. The validity of broilers altering feed intake in response to dietary energy has been questioned for some time and more recent evidence suggests that modern strains of laying hens also are unable to accurately or reliably alter feed intake in response to dietary energy levels. Based on the premise that chickens do not appropriately respond to dietary energy, diets must therefore be formulated to ensure adequate dietary energy to meet the bird’s requirements for maintenance and production, and thereby maximize the protein accretion potential of the diet.

Myo-inositol (inositol) affects memory, and the incidence of depression and anxiety in mammals. An experiment was designed to determine if pure inositol (0.16%), or high levels of phytase (3000 FTU/kg) affect the behaviour of fully beaked Lohmann LSL lite hens fed amino acid sufficient (19% crude protein (CP)) and deficient diets (16% CP), from 19 to 59 weeks of age. The data collected included live-scan behaviour observations and novel object (NO) tests (both at 1, 10 and 40 weeks of the trial), heterophil-to-lymphocyte (H/L) ratios (week 1 and week 40 of the trial), end of trial feather cover, and comb and skin lesions, and daily mortality. Reducing CP increased sitting by 2.5%. Inositol, but not phytase, reduced the latency to peck at the NO by 300 sec. Inositol reduced vent feather cover by 12% and tended to increase mortality by 13%. No effects on H/L ratio, and comb or skin lesions were found. In conclusion, regardless of the source, inositol reduced vent feather cover, while it tended to increase mortality. Only pure inositol reduced fearfulness in laying hens.

This research examined how infrared beak treatment (IRBT), sloughing of the treated beak tissue, and the variations in beak shape that can occur post-IRBT impact the welfare and mortality of Lohmann LSL-Lite (LW) and Lohmann Brown (LB) pullets and hens. Two experiments were conducted and birds for both experiments were treated on the day of hatch. IRBT equipment settings were adjusted to create 4 specific beak shapes: shovel (SHV), step (STP), standard (STAN), and an untreated sham control (C). Experiment 1 pullets (n = 80 per strain) were reared in bioassay cages from 1 to 29 D of age (4 replicates per treatment). Data collected included time and presence of beak sloughing, pecking force, behavioral expression, and mortality. Experiment 2 pullets (n = 320 per strain) were reared in floor pens from 1 D to 18 wk of age (2 replicates per treatment) and then conventional cages from 18 to 60 wk of age (6 replicates per treatment). Data collected for Experiment 2 included behavioral expression, feather cover, comb damage, and mortality. Data were analyzed using PROC MIXED (SAS® 9.4) with Tukey's test to separate means. Differences were significant when P ≤ 0.05. IRBT and sloughing had no effect on pecking force or mortality throughout rearing. The variations in post-IRBT beak shape had minor effects on behavior. During rearing, STAN pullets were more active than C pullets but STP and STAN pullets performed less exploratory pecking. During the laying period, SHV and STP hens preened more than C hens. The IRBT treatments, regardless of beak shape, reduced feather loss, comb damage, and cannibalism-related mortality during the laying period. Overall, the results indicate that LW and LB pullets and hens can cope with the change in beak shape that occurs with IRBT, and that welfare is not negatively impacted if some variation in beak shape occurs.

Introduction Limited use of medication in poultry feed led to the investigation of exogenous enzymes as antibiotic alternatives for controlling enteric disease. The objective of this study was to evaluate the effects of diet β-glucanase (BGase) and medication on β-glucan depolymerization, digestive tract characteristics, and growth performance of broilers. Materials and methods Broilers were fed hulless barley (HB) based diets with BGase (Econase GT 200P from AB Vista; 0 and 0.1%) and medication (Bacitracin and Salinomycin Na; with and without) arranged as a 2 × 2 factorial. In Experiment 1, 160 broilers were housed in cages from d 0 to 28. Each treatment was assigned to 10 cages. In Experiment 2, broilers (2376) were housed in floor pens and vaccinated for coccidiosis on d 5. Each treatment was assigned to one floor pen in each of nine rooms. Results In Experiment 1, the soluble β-glucan weighted average molecular weight (Mw) in the ileal digesta was lower with medication in the 0% BGase treatments. Peak molecular weight (Mp) and Mw were lower with BGase regardless of medication. The maximum molecular weight for the smallest 10% β-glucan (MW-10%) was lower with BGase addition. In Experiment 2, Mp was lower with medication in 0% BGase treatments. Beta-glucanase resulted in lower Mp regardless of medication, and the degree of response was lower with medication. The MW-10% was lower with BGase despite antibiotic addition. Body weight gain and feed efficiency were higher with medication regardless of BGase use through-out the trial (except d 11–22 feed efficiency). Beta-glucanase resulted in higher body weight gain after d 11 and worsened and improved feed efficiency before and after d 11, respectively, in unmedicated treatments. Conclusion BGase and medication caused the depolymerization of soluble ileal β-glucan. Beta-glucanase acted as a partial replacement for diet medication by increasing growth performance in coccidiosis vaccinated broilers.

The impact of mild hot-blade beak trimming on welfare and performance in 2 strains of White Leghorn pullets was examined. During the pullet phase, 960 pullets were designated to one of 4 trimming treatments: control (untrimmed, C), trimmed at a commercial hatchery (T0d), or trimmed on farm at 10 d (T10d) or 35 d (T35d) of age. During the hen phase, 720 of the original 960 hens were housed in conventional cages at 17 wk of age (6 replications per strain × treatment group) and data were analyzed as a 2 × 4 (performance and beak length data), 2 × 2 (behavior data, blocked by observer) factorial arrangement or a Chi-Squared analysis (beak healing). Total hen-day production tended to be lower for C birds, but hen-housed production did not differ. Feed intake was not affected by trimming treatments, but feed efficiency was poorer for C birds. Treatment did not statistically affect mortality. Cannibalism, although not significantly different among treatments, occurred in C birds only. The C pullets displayed more head/vent pecking, but no differences were noted in adult birds. There was no behavioral or histological evidence of chronic pain or neuroma formation, and healing occurred quicker when trimming occurred at zero or 10 d of age. To conclude, trimming mildly at zero, 10, or 35 d of age caused no long-term effect on welfare or performance, but trimming at younger ages resulted in faster healing.

The importance of the crop is often underestimated in poultry production. In addition to storing ingested feed, it also can impact nutrient digestion by digesta softening and the initial activity of feed (endogenous and exogenous) and microbial enzymes. The crop represents the first major defence against poultry pathogens and zoonotic organisms with well established adaptive and innate immune function, and a lactobacilli dominated microbiota capable of reducing the passage of these organisms further along the digestive tract. However, the potential to improve bird productivity and health, as well as affect meat and egg safety, are influenced by the nature of the diet, and in particular feed entry and extended presence in the crop. This is required to promote lactobacilli fermentation, the production of lactic acid and other volatile fatty acids, and the lowering of crop pH. Management practices such as meal feeding and the use of lighting programs with extended dark periods encourage crop utilisation. Further, the use of feed additives such as prebiotics and probiotics may enhance crop function, which in turn contributes to well-being of the entire digestive tract. A healthy and functional crop, along with other segments of digestive tract, has increased importance in an era of reduced antibiotic use in poultry feeds.

Objective The objective of this study is to investigate the structural and functional ocular changes that develop in turkeys exposed to a photoperiod of 23 h of light (23L) compared with a photoperiod of 14 h of light (14L). Procedures Ten-day-old Nicholas heavy strain poults were exposed to either a 14L or 23L photoperiod. Between 16 and 18 weeks of age, equal numbers of turkeys per treatment group underwent ophthalmic examination (biomicroscopy, indirect ophthalmoscopy) (n = 14), refractometry (n = 20), keratometry (n = 20), tonometry (n = 20), and full-field electroretinography (ERG) (n = 14). Postmortem analyses included orbital magnetic resonance imaging (MRI) (n = 10) and light microscopy (n = 24) at 18 weeks of age. Results Autorefraction revealed a median of −0.13 for sphere in both groups (P = 0.69), which is approximately emmetropia. The radius of curvature of the cornea was significantly higher (P = 0.0001) and the refractive power of the cornea was significantly lower (P = 0.0001) in the 23L group. The astigmatic power was significantly greater in the 23L group (P = 0.0001). Mean intraocular pressure did not differ between groups (P = 0.085). Turkeys from the 23L group had significantly larger globes in nasotemporal (P = 0.0007), dorsoventral (P = 0.015), and anterioposterior (P = 0.021) directions, and anterior chambers were more shallow (P = 0.0002). ERGs revealed the 23L group to have lower a- and b-wave amplitudes and significantly lower cone flicker amplitudes (P = 0.0008). Light microscopic examination revealed 23L turkeys to have significantly decreased numbers of nuclei in the outer nuclear layer (P = 0.0001) and inner nuclear layer (P = 0.0186), and decreased choroidal thickness (P = 0.0008). The prevalence of cataract in the 23L group was significantly higher (P = 0.001). Conclusions Exposing turkeys to a prolonged photoperiod induces significant ocular disease.

The impact of graded levels of day length on turkey health and behavior was determined in hens and toms raised to 18 wk of age. Birds were allocated to one of 4 lighting treatments (trt) providing 14 (14L), 17 (17L), 20 (20L), and 23 (23L) h of day length. Two time-replicated trials were completed with each, providing 2 rooms per lighting trt and each room having 3 hen (n = 720) and 3 tom (n = 480) pens. Data collection included gait score (GS), the incidence of footpad dermatitis (FPD), breast buttons and blisters, ocular size and pressure (males only), and behavioral observations (males only). Data were analyzed using SAS 9.3 based on a completely randomized design nested within 4 lighting trt. Regression analysis established relationships between response criteria and day length. Differences were considered significant at P ≤ 0.05 and trends noted at P ≤ 0.10. Gait score, FPD, and the incidence of breast buttons and blisters were assessed on 5 birds per pen at 11 and 17 wk of age. Average GS increased linearly with day length at 11 and 17 wk for both hens and toms, but the effect was larger in toms. Day length did not affect FPD, but more lesions and severe scores were found for hens than toms. The presence of breast buttons and blisters increased linearly with day length (11 wk) with the effect on blisters predominately seen in toms. Eye weight and size increased with increasing day length at 12 and 18 wk. Ocular pressure was not affected by day length. Infrared cameras recorded tom behavior over a 24 h period, and behaviors were classified over 10-min intervals using a scan sampling technique at 11 and 17 wk. Alterations in behavioral repertoire were observed with a linear increase in inactive resting and a linear decrease in standing, walking, preening, and environmental and feather pecking behaviors with increased day length. To conclude, day length affected bird mobility and incidence of breast blisters in an age- and gender-specific manner, and time spent inactive increased with longer day length.

Two trials were conducted to study the effect of feeding barley silage on the behaviour and performance of beak-trimmed laying hens. In each trial, 20 hens and 2 roosters were housed in each of eight group-housed enriched cages, with four cages provided a laying hen diet and four cages additionally given free access to barley silage. Egg production and quality, and hen behaviour were assessed throughout the trials (Trial One 20–30 weeks; Trial Two 19–28 weeks). Data were analysed using Proc Mixed of SAS 9.4 and differences were significant when P ≤ 0.05. Silage-fed hens consumed 41 (13.9 g DM) and 50 (13.5 g DM) grams of silage per hen per day in Trials One and Two, respectively, while consuming less layer diet. Birds fed silage spent less time expressing aggressive and feather-pecking behaviours and in nest boxes, and more time feeding than control birds. Egg production, egg quality, and bird weight were not affected by treatment; yolk colour was darker for the silage treatment. Feathering quality was improved in silage-fed birds compared to control birds. It was concluded that providing hens with access to barley silage can improve welfare indicators without negatively affecting the egg production and egg quality.

The chicken Major Histocompatibility Complex (MHC) is very strongly associated with disease resistance and thus is a very important region of the chicken genome. Historically, MHC (B locus) has been identified by the use of serology with haplotype specific alloantisera. These antisera can be difficult to produce and frequently cross-react with multiple haplotypes and hence their application is generally limited to inbred and MHC-defined lines. As a consequence, very little information about MHC variability in heritage chicken breeds is available. DNA-based methods are now available for examining MHC variability in these previously uncharacterized populations. A high density SNP panel consisting of 101 SNP that span a 230,000 bp region of the chicken MHC was used to examine MHC variability in 17 heritage populations of chickens from five universities from Canada and the United States. The breeds included 6 heritage broiler lines, 3 Barred Plymouth Rock, 2 New Hampshire and one each of Rhode Island Red, Light Sussex, White Leghorn, Dark Brown Leghorn, and 2 synthetic lines. These heritage breeds contained from one to 11 haplotypes per line. A total of 52 unique MHC haplotypes were found with only 10 of them identical to serologically defined haplotypes. Furthermore, nine MHC recombinants with their respective parental haplotypes were identified. This survey confirms the value of these non-commercially utilized lines in maintaining genetic diversity. The identification of multiple MHC haplotypes and novel MHC recombinants indicates that diversity is being generated and maintained within these heritage populations.

The objective of this research was to evaluate activation of the ileal brake in broiler chickens using diets containing semi-purified wheat (WS; rapidly and highly digested) and pea (PS; slowly and poorly digested) starch. Diets were formulated to contain six WS:PS ratios (100:0, 80:20, 60:40, 40:60, 20:80, 0:100) and each starch ratio was fed to 236 Ross 308 male broilers housed in 4 litter floor pens. At 28 d of age, the effect of PS concentration was assessed on starch digestion, digestive tract morphology, and digesta pH and short-chain fatty acid (SCFA) concentration. Glucagon-like peptide-1 (GLP-1) and peptide tyrosine-tyrosine (PYY) status were assessed in serum (ELISA) and via gene expression in jejunal and ileal tissue (proglucagon for GLP-1). Data were analyzed using regression analyses, and significance was accepted at P ≤ 0.05. Increasing dietary PS resulted in reduced starch digestibility in the small intestine, but had no effect in the colon. Crop content pH responded quadratically to PS level with an estimated minimum at 55% PS. Total SCFA increased linearly in the crop with PS level, but changed in a quadratic fashion in the ileum (estimated maximum at 62% PS). Ceacal SCFA concentrations were highest for the 80 and 100% PS levels. The relative empty weight (crop, small intestine, colon), length (small intestine) and content (crop jejunum, Ileum) of digestive tract sections increased linearly with increasing PS concentration. Dietary treatment did not affect serum GLP-1 or PYY or small intestine transcript abundance. In conclusion, feeding PS increased the presence of L-cell activators (starch, SCFA) and increased trophic development and content of the digestive tract, suggestive of L-cell activation. However, no direct evidence of ileal brake activation was found by measuring venous blood levels of GLP-1 or PYY or corresponding gene expression in small intestine tissue.

Gnotobiotic broiler chickens were used to study interactive effects of supplemented phosphorus, calcium (PCa), and phytase (Phy) on myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate) (InsP6) degradation and release of myo-inositol in the digestive tract. In 2 subsequent runs, the chickens were subjected to 1 of 4 dietary treatments with and without PCa and Phy supplementation. Sanitized eggs were hatched in 8 germfree isolators, and a minimum of 9 male Ross 308 chickens were placed in each pen (total 16 pens). Treatments implemented on day 10 included gamma-irradiated diets without (PCa−; 4.1g P and 6.2g Ca/kg DM) or with (PCa+; 6.9g P and 10.4g Ca/kg DM) monosodium phosphate and limestone supplementation and without (Phy−) or with (Phy+) 1,500 FTU Phy/kg feed in a factorial arrangement. On day 15, digesta was collected from different sections of the intestinal tract and analyzed for InsP isomers and myo-inositol. The isolators did not remain germfree, but analysis of contaminants and results of InsP degradation indicated no or minor effects of the identified contaminants. Prececal InsP6 disappearance was 42% with the PCa− Phy− treatment and 17% with PCa+Phy−. No InsP3–4 isomers were found in the digesta of the terminal ileum in PCa− Phy−. The concentration of myo-inositol in the ileal digesta from PCa− Phy− (6.1μmol/g DM) was significantly higher than that from PCa+Phy− (1.7μmol/g DM), suggesting rapid degradation of the lower InsP isomers by mucosal phosphatases and their inhibition by PCa. Phytase supplementation increased InsP6 disappearance and prevented inhibitory effects of PCa supplements (72% in PCa− Phy+ and 67% in PCa+Phy+). However, PCa supplementation reduced the degradation of lower InsP isomers mainly in the posterior intestinal sections in the presence of Phy, resulting in significantly lower myo-inositol concentrations. It is concluded that mucosa-derived phosphatases might significantly contribute to InsP6 degradation in broiler chickens. The potential of mucosa-derived phosphatases to degrade InsP6 and lower InsP is markedly reduced by dietary PCa supplementation.

The inclusion of starch with a lower rate and extent of digestion has proven to be beneficial in broiler production. However, less is known about its effect on laying hen performance. Therefore, 6 diets were formulated to produce differing ratios (0:100, 20:80, 40:60, 60:40, 80:20, and 100:0) of semi-purified wheat starch (rapidly digested) and pea starch (PS; slowly digested). Each diet was fed to 120 conventionally caged Lohmann LSL lite hens in groups of 12, from 27 to 46 wk of age, and its effects on performance and feather covering were assessed. Data were analyzed by regression analysis, and the significance level was chosen at P ≤ 0.05. Hen-day egg production (HDP) was high (97.05%) and unaffected by PS concentration for 0 to 10 wk of the trial, followed by a quadratic-shaped HDP, with an estimated maximum at 67% PS concentration, for the 10 to 20 wk period of the trial. Overall (0 to 20 wk), HDP increased linearly with PS. No effect on egg weight was found (average weight = 59.6±2.1 g), but eggshells were thickest at the 55% PS concentration. Body weight gain was affected by PS concentration and maximized at 49% PS. Body weight uniformity and mortality were not affected by dietary treatment. Feed intake increased linearly with PS from 102 to 109 g/hen/d, while feed: egg mass ratio was minimal at 26% PS. Using a scale from 1 to 4 per body part (neck, wings, back, vent and breast), only neck feather cover increased linearly with PS, from 3.0 (0% PS) to 3.2/4 (100% PS). However, back and total feather coverage showed a trend (P = 0.054 and P = 0.079 respectively) to increase linearly with PS as well (from 3.7 to 3.9/4 and 15.6 to 16.6/20, respectively). In summary, feeding PS at low to intermediate concentrations improved laying hen performance. Further research should focus on the mechanisms involved in this effect.

It is difficult to obtain in vivo digestion kinetics data of high protein ingredients using chickens. Collecting kinetics data requires repeated sampling of digesta from the small intestine during the digestion process, which is not easily accomplished due to the anatomical structure of chicken digestive tract. An in vitro technique is proposed for measuring the digestion kinetics of protein sources fed to chickens. The method has a 30 min gastric and 3 h intestinal phase. Five hundred milligram crude protein (CP) equivalent of each meal sample (CP = % N × 6.25) was digested with pepsin (28,260 units) in 50 mL polyethylene centrifuge tubes for 30 min in a shaking water bath (150 strokes/min; 30 mm stroke length) at 41 °C. The 6.5 mL pancreatin was selected as the enzyme concentration for the intestinal phase, during which time 500 μL aliquots were collected at 0, 15, 30, 45, 60, 90, 120, 150, 180 and 240 min. Samples were diluted 1:820 with HCl and sodium acetate buffer, and then mixed with ninhydrin reagent (2:1) at 100 ± 2 °C for 15 min and spectrometric readings taken at 568 nm. To validate the assay, 5 replications of soybean meal (SBM), corn gluten meal (CGM), corn distillers dried grains with solubles (CDDGS), porcine meal (PCM), fish meal (FM) and casein (CA) were digested. The digestion data were modeled with PROC NLIN procedure, and the intra coefficient of variation (CV) assessed using PROC MEANS of SAS 9.4. The digestion values at 180 min were SBM 95 ± 4, FM 93 ± 3, PCM 68 ± 4, CGM 82 ± 3 and CDDGS 70 ± 2. Intra CV for SBM, CGM, CDDGS, PCM and FM were 5%, 5%, 12%, 10% and 2%, respectively. The estimated fractional digestion rates for SBM, CGM, CDDGS, FM and PCM were 0.023, 0.013, 0.009, 0.024 and 0.013, respectively. In conclusion, the proposed in vitro technique estimated the rate and extent of the digestion of CP for the meals with low intra CV.

It is becoming a common practice to use higher levels of wheat distillers dried grains with solubles (wDDGS) in poultry diets. The objective of this study was to determine the effects of level of inclusion of wDDGS with or without enzyme (E-, i.e., wDDGSE-) supplementation on performance and water consumption of turkey hens (0 to 72 d). Two diets (0 or 30% wDDGS) were formulated to meet the nutrient requirements of Hybrid Converter turkeys. Diets (0 or 30% wDDGS; starter, grower, and finisher) were then blended to obtain a different level of inclusion (15%) of wDDGS. The 30% wDDGS diet was divided into 3 fractions and 2 fractions supplemented with either protease (P+, i.e., wDDGSP+; 0.126 g/kg) or β-mannanase (M+, i.e., wDDGSM+; 0.05 g/kg). All 5 diets were fed ad libitum as mash. The 700 0-d turkey hens were randomly allocated into groups of 35 birds per replicate with 4 replicate floor pens per treatment, in a completely randomized design. Water consumption per pen was recorded beginning at 7 d. There was no effect of dietary treatment on feed intake. BW of turkey hens (52 d; grower) was significantly higher for 30% wDDGSP+ as compared to 0% wDDGSE- or 15% wDDGSE- diets; but was not different from 30% wDDGSE- or 30% wDDGSM+ diets. FCR (P0.01; 28 to 52 d), and total FCR (P0.05; 0 to 72 d) was significantly improved for birds fed 15 or 30% wDDGS regardless of enzyme treatment compared to 0% wDDGSE-. Water intake (WI, in mL per bird per day) tended to be higher (P = 0.08) between 7 and 28 d for 30% wDDGSP+ diets compared to other treatments. Similarly, WI of birds fed 30% wDDGSP+ was higher (P0.05; 28 to 52 and 52 to 72 d) and total WI (P = 0.07; 7 to 72 d) tended to be higher than other treatments. This study is the first to report the impact of wDDGS on WI. As high as 30% wDDGS can be substituted in turkey hen diets. No effect of P+ or M+ at the inclusion level tested was found on performance.

Society is increasingly concerned about the welfare of animals kept for food production, for this reason, invasive procedures such as toe trimming in turkeys must be studied to assess the corresponding welfare implications and to ensure such procedures are acceptable for continued use. To this end, research was conducted to evaluate the welfare effects of toe trimming on toms raised to 140 d. The study used 306 Hybrid Converter toms, half of which were toe trimmed using a Microwave Claw Processor (MCP) which group are denoted T, and half of which were sham treated but not trimmed, which group are denoted NT. Turkey behavior was observed on d 1, 3, 5, and 133. Toe cross sections were taken every second day for 14 d after treatment and were used to histologically examine the healing process. Toe length, gait score, and bird stance were assessed on d 55, 84, 119, and 139. For the first 5 d after treatment, T birds demonstrated less active behaviors such as feeding, standing, walking and running (P ≤ 0.05), indicative of pain with the effect diminishing with age. At d 133, T turkeys stood more and walked less than NT birds (P ≤ 0.05). Gait score and bird stance were not affected by treatment. Trimmed toes were on average 91.9% of the length of NT toes and toe length was more variable (P ≤ 0.05) as a result of the trimming process. Histological examination indicated T toes had complete epithelium closure over the healthy tissue by d 8 and were fully healed by d 14. Although bird mobility and stance were unaffected by treatment, turkey behavior both early and late in the production cycle were suggestive of pain and balance effects; both indicators of reduced welfare as a result of toe trimming.

Two experiments were conducted to determine if extrusion (EX) or enzymes (E) could overcome the restrictions (e.g., high fiber) of feeding wheat distillers dried grain with solubles (wDDGS) and improve its nutritional value for feeding turkeys. Two starter diets with either 0 or 30% wDDGS were formulated to meet or exceed the nutrient requirements of the Hybrid Converter female turkeys. The 30% wDDGS diet was substituted with either non-extruded (EX–) or extruded (EX+) wDDGS to produce three basal diets [0% wDDGS (EX–) or 30% wDDGS (EX–/EX+)]. Diets were blended to obtain 15% wDDGS. In the respective treatments, only wDDGS was extruded (temperature; 118°C, retention; 15 sec, total moisture; 25% and pressure 33 bar). The respective experimental diets were supplemented with/without an enzyme cocktail (E; 0.5 g/kg). Test diets were fed from 7−21 d in a completely randomized design. In Experiment 1, a total of 210 turkey hen poults were fed diets containing 0, 15, or 30% wDDGS (EX–) with or without enzyme (E+/E–). Body weight (BW) and feed intake (FI) were significantly higher for 0% wDDGSE–. Nitrogen retention (NR) and apparent metabolizable energy (AME) for the 30% wDDGSE– was significantly higher than other treatments at 21 d. The results indicated significant main effects of E and an interaction between wDDGS level and E. In Experiment 2, 280 turkey hen poults were fed 8 diets [15/30% wDDGS (E+/E–), (EX–/EX+)]. The level of wDDGS had a significant effect on BW, FI and gain:feed; 15% inclusion was superior to 30%. There were significant 2- and 3-way interactions for AME and NR at 21 d due to differences in enzyme response with 15 or 30% wDDGS inclusion and/or extrusion of wDDGS. As high as 15% wDDGS can be incorporated in turkey hen diets. There were no beneficial effects of EX or E on poult performance.