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SUMMARY: As hens age, egg production and quality decline. Producers are interested in extending the production of their hens to help with production costs and demand. The objective of this study was to investigate the role of the ratio of fine (F) and coarse (C) limestone and exogenous phytase at standard and superdosing levels on performance and egg quality of post-peak hens from 40 to 60 wk of age. A total of 560 Hy-Line W-36 hens (20 replicates of 4 hens per treatment) were randomly assigned into 7 experimental diets in a 2 × 3 + 1 factorial arrangement. The positive control (PC) was formulated to an industry standard that consisted of a 40F:60C limestone ratio without phytase and contained 4.4% calcium (Ca) and 0.44% available phosphorus (avP) for both layer 2 and layer 3 diets. A common negative control (NC) diet was created by reducing Ca and avP by 0.19% and 0.17% respectively compared with the PC. The factorial treatments consisted of 2 limestone ratios (40F:60C and 15F:85C) and 3 Escherichia coli-derived phytase levels (0, 400, and 1,500 FTU/kg) formulated from the NC. Results indicated that 40F:60C at 0 and 400 FTU/kg increased hen-day egg production (HDEP). Limestone ratios of 15F:85C decreased feed intake (FI), increased both eggshell thickness (ST) and weight (SW), but also increased unsaleable eggs (UE) compared to 40F:60C. Additionally, 0 and 400 FTU/kg increased egg quality parameters such as Haugh unit (HU) and albumen height (AH) but 1,500 FTU/kg increased inositol phosphate breakdown as well as bone quality.

ABSTRACT: This study evaluated the effects of 25-hydroxycholecalciferol (25-OHD) on performance, gut health, and bone quality of broilers fed with reduced calcium (Ca) and phosphorus (P) diet during Eimeria spp. challenge. A total of 576 fourteen-day-old Cobb 500 male chicks were randomly distributed in a 2 × 2 × 2 factorial arrangement, with 6 replicates of 12 birds each. The main factors were 25-OHD level (0 or 3,000 IU/kg of feed), mineral level (0.84% of Ca/0.42% of P, the levels recommended for the grower phase (NOR) or 0.64% of Ca/0.22% of P (RED), and mid-high mixed Eimeria challenge or nonchallenge. 25-OHD improved phosphorus retention (P = 0.019), bone ash weight (P = 0.04), cortical bone trabecular connectivity (P = 0.043) during coccidiosis. For birds fed with reduced mineral levels, 25-OHD supplementation increased bone ash weight (P = 0.04). However, 25-OHD did not improve bone ash weight when birds were challenged and fed with reduced mineral levels. The dietary 3,000 IU of 25-OHD supplementation did not improve performance or gut morphology but support bone health during coccidiosis. Future investigations are needed for better understand 25-OHD role on bone microarchitecture and oxidative metabolism during coccidiosis.

ABSTRACT: This study was conducted to evaluate the prebiotic effect of xylo-oligosaccharide (XOS) supplemented in a corn-soybean meal (SBM) based conventional diet on growth performance, intestinal histomorphology, and quantification of specific bacteria in the ceca of broilers. A total of 240 d of hatch Cobb 500 male broiler chicks were randomly assigned to 4 dietary treatments (corn-SBM-based control diet) containing 0, 0.05, 0.1, and 0.2% XOS.The broilers were raised for 21 d in 6 replicate cages, each containing 10 birds. Growth performance parameters were obtained weekly. Additionally, small intestinal tissues were collected to evaluate histomorphometry and whole ceca were collected to quantify bacterial populations on D21. The results showed that inclusion of XOS has similar body weight (BW), body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) as the control group during the 21-day study. The results further indicate a tendency for the jejunum villus to crypt ratio (VH:CD) to increase in birds given 0.05 and 0.2% XOS (P = 0.08). Cecal bacteria quantification showed a linear increase in Bifidobacterium with increasing XOS levels (P < 0.0001) and a decrease Clostridium perfringens levels compared to birds fed the control diet (P < 0.0001). However, there were no differences in the total counts of Lactobacillus and E. coli. Together these results showed that while there were no differences in growth parameters up to 21 d, the histomorphology findings and the increase in Bifidobacterium, along with the reduction in C. perfringens observed in the XOS groups, suggest a beneficial impact of XOS inclusion on gut health. Further research with longer feeding periods and higher XOS levels should be conducted to explore potential positive effects on both growth and gut health parameters.

ABSTRACT: Necrotic enteritis (NE) is a widespread infectious disease caused by Clostridium perfringens that inflicts major economic losses on the global poultry industry. Due to regulations on antibiotic use in poultry production, there is an urgent need for alternative strategies to mitigate the negative effects of NE. This paper presents a passive immunization technology that utilizes hyperimmune egg yolk immunoglobulin Y (IgY) specific to the major immunodominant antigens of C. perfringens. Egg yolk IgYs were generated by immunizing hens with 4 different recombinant C. perfringens antigens, and their protective effects against NE were evaluated in commercial broilers. Six different spray-dried egg powders were produced using recombinant C. perfringens antigens: α-toxin, NE B-like toxin (NetB; EB), elongation factor-Tu (ET), pyruvate:ferredoxin oxidoreductase, a mixture of 4 antigens (EM-1), and a nonimmunized control (EC). The challenged groups were either provided with different egg powders at a 1% level or no egg powders (EN). The NE challenge model based on Eimeria maxima and C. perfringens dual infection was used. In Experiments 1 and 2, the EB and ET groups exhibited increased body weight gain (BWG; P < 0.01), decreased NE lesion scores (P < 0.001), and reduced serum NetB levels (P < 0.01) compared to the EN and EC groups. IgY against NetB significantly reduced Leghorn male hepatocellular cytotoxicity in an in vitro test (P < 0.01). In Experiment 3, the protective effect of the IgYs mixture (EM-2) against C. perfringens antigens (NetB and EFTu) and Eimeria antigens (elongation factor-1-alpha: EF1α and Eimeria profilin: 3-1E) was tested. The EM-2 group showed similar body weight, BWG, and feed intake from d 7 to 22 compared to the NC group (P < 0.05). On d 20, the EM-2 group showed comparable intestinal permeability, NE lesion scores, and jejunal NetB and collagen adhesion protein levels to the NC group (P < 0.05). In conclusion, dietary mixture containing antibodies to NetB and EFTu provides protection against experimental NE in chickens through passive immunization.

ABSTRACT: Broiler breeder feed restriction practices have intensified as broiler feed efficiency has been improved. Skip-a-day (SAD) rearing regimen has controlled breeder growth, although this practice has become questionable for the modern breeder. We compared everyday (ED) and SAD programs and evaluated their impact on pullet growth performance, body composition, gastrointestinal tract development, and reproduction. At d 0, Ross 708 (Aviagen) pullet chicks (n = 1,778) were randomly assigned to 7 floor pens. Three pens were fed using the ED and 4 pens with SAD program through wk 21 using a chain-feeder system. ED and SAD grower diets were formulated to be isonutritious, with the only difference that ED diets had more crude fiber. Pullets (n = 44 per pen) were moved to 16 hen pens by treatment at wk 21 with 3 YP males (Aviagen) in each pen. All birds were fed common laying diets. In addition to BW data, sampled pullets and hens were scanned using dual energy X-ray absorptiometry (DEXA) to obtain body bone density and composition. Hen performance and hatchery metrics were recorded through wk 60. ED birds were heavier with similar nutrient intake from wk 10 to 45 (P ≤ 0.013). Pullet uniformity was unaffected by feeding method (P ≥ 0.443). SAD pullets had less body fat at wk 19 (P = 0.034) compared to ED pullets, likely as a metabolic consequence of intermittent feeding. SAD birds had lower bone density at wk 7, 15, and 19 (P ≤ 0.026). At 4 wk of age, SAD pullets had less intestinal villi goblet cells compared to ED pullets (P ≤ 0.050), possibly explained by the effect that feed removal has on cell migration rates. Overall egg-specific gravity (P = 0.057) and hatch of fertile % (P = 0.088) tended to be higher in eggs from ED hens. Altogether, ED feeding increased young pullet intestinal goblet cells and increased both bone density and body fat at wk 19. ED program improved pullet feed conversion (2.6% less feed) and increased eggshell quality and hatch of fertile.

SUMMARY: Supplementing exogenous proteases in poultry diets was shown to facilitate the digestion of dietary proteins. However, there is limited information on the effects of proteases inclusion on performance of broiler chickens fed reduced energy, protein, and essential amino acid (EAA) diets. This study aimed to address this gap in knowledge. A total of 720 one-day-old Cobb 500 male broilers were randomly allocated to 6 treatments and 6 replicates of 20 birds. The treatments included: positive control (PC; formulated as per the breeder guideline), negative control (NC; reduction in nutrition levels by 100 kcal/kg ME; 1% CP, and 5% EAAs), and NC diets supplemented with 50 g/t, 100 g/t, 200 g/t, 400 g/t of Vitazyme Pro protease (NC 50, NC 100, NC 200, and NC 400). From d 1 to 14 and 14 to 28, all nutrient reduction groups, except for NC 100, had higher FCR (P < 0.05) than PC. From d 28 to 42, the NC group had higher (P < 0.01) FI and FCR than PC. However, protease supplementation from 100 to 400 g/t maintained the higher FI (P < 0.01) while increased BWG (P < 0.01) compared to PC. For the entire 42-d period, PC and NC 100 had lower (P < 0.01) FCR than NC and NC 50. In conclusion, the results suggested that protease supplementation could mitigate the negative impacts of reductions in dietary nutrition levels on growth performance. The inclusion of Vitazyme PRO protease at 100 g/t seemed to be optimal for improving growth performance in diets with reduced energy, protein, and EAAs.

SUMMARY: Dietary trace minerals have profound functions in broiler breeder reproduction. Organic hydroxy analog of methionine (HMTBa) trace minerals have been included at lower levels in poultry feeds compared to inorganic sources without affecting performance and in some cases improving it. We compared 3 breeder hen trace mineral blends of economic interest to a large U.S. integrator. Treatment diets (fed wk 26–65) provided Zn, Mn, and Cu (mg/kg), respectively: CTL = control, predominantly inorganic trace minerals (143–180–123); ORG = reduced levels using solely HMTBa trace minerals (50–60–15); and MIX = a blend of inorganic/HMTBa trace minerals (75/25–90/30–22.5/7.5). On average, ORG-fed hens were 1.3 and 1.1% heavier compared to CTL and MIX hens, respectively (P = 0.002). Overall (wk 25–65), hens fed the MIX diet had higher egg production (P < 0.001) and laid heavier eggs (P = 0.038) compared to hens fed the CTL or ORG diet. During the second half of lay, MIX-fed hens showed improved eggshell quality (P ≤ 0.037) and cuticle deposition (P = 0.019). Fertility and hatchability were unaffected by diet (P ≥ 0.205). Broilers hatched from young ORG hens (29 wk) had higher bone mineral density (P = 0.004) and after a 7-day grow-out (P = 0.047) when obtained from ORG hens of 41 wk of age. In conclusion, the industry levels provided by combining inorganic and HMTBa trace minerals in breeder hen diets were advantageous for sustaining high-quality settable egg production.

ABSTRACT: The objective of the study was to investigate the effects of a dacitic tuff breccia (DTB) on Eimeria-infected broilers. A total of 600 one-day-old Cobb 500 male chickens were randomly assigned to 5 treatments with 10 replicates of 12 birds. Treatments were: an unchallenged control (UC), a challenged (CC) control (0% DTB), and 3 challenged groups with 0.125, 0.25, or 0.5% DTB. At d 14, birds in the CC and DTB groups were orally gavaged with mixed Eimeria spp., while the UC received water. Growth performance was evaluated during prechallenge, challenge, and postchallenge periods (0–14 d; 14–20 d; and 20–26 d, respectively). Gastrointestinal permeability was measured at 5 days postinfection (dpi). Intestinal histology and nutrient digestibility of dry matter (DM), crude protein (CP), and ileal digestible energy (IDE) were measured at 6 dpi. Liver activity of glutathione peroxidase (GSH-Px) was determined at 6 dpi, and concentrations of reduced (GSH) and oxidized glutathione (GSSG) were analyzed at 6 and 12 dpi. Data were analyzed using a linear mixed model analysis and Tukey's test (P ≤ 0.05). From 0 to 14 d, similar average daily gain (ADG) and average daily feed intake (ADFI, P > 0.05) were observed. Gain:feed ratio (GF) was higher in 0.125, 0.25, and 0.5% of DTB than the CC and UC (P < 0.001). From 14 to 20 d, the UC had the highest ADG, ADFI, and GF (P < 0.001). At 5 dpi, intestinal permeability was higher in the challenged groups than the UC. Additionally, the UC showed the highest apparent ileal digestibility of CP, whereas 0.125% DTB had higher CP digestibility than the CC and 0.5% DTB (P < 0.001). At 6 dpi, 0.125% DTB increased GSH-Px activity compared to the CC, 0.5% DTB, and UC (P < 0.001). At 12 dpi, 0.125% DTB showed increased GSH concentration compared to the CC, 0.25% DTB, and 0.5% DTB (P < 0.01). The mild coccidia infection negatively impacted growth performance, apparent ileal nutrient digestibility, intestinal histology, and gastrointestinal integrity in broilers. The use of 0.125% DTB exhibited potential in improving antioxidant responses, apparent ileal digestibility of CP, and growth performance.

SUMMARY: A study was conducted to assess the effectiveness of yeast-derived products in the recovery of Salmonella Enteritidis (SE) in White Leghorns. A total of 32 hens at 38 wk of age were challenged both orally (OR) and intracloacally (IC) with nalidixic acid resistant SE (SENAR). Hens were individually housed in conventional wire laying cages and randomly allocated to 4 treatments (T) with 8 hens per replicate: 1) No SENAR challenge (T1; basal diet), 2) SENAR challenge (T2; basal diet), 3) SENAR challenge: basal diet with a blend of Saccharomyces-Torula yeasts and yeast cell walls (T3; intact yeast), and 4) SENAR challenge: basal diet with enzymatically-modified yeast products blend (T4; enzyme-modified yeast). The excreta samples were 100% positive for SENAR at 3 d postinfection (dpi) in T2, T3, and T4. By 6 dpi, excreta samples were 87, 62 and 37% positive for T2, T3, and T4, respectively. Hens were euthanized at 7 dpi to harvest liver with gall bladder (L/GB), spleen, ovaries, and ceca. The recovery of SENAR in L/GB was 75, 25, and 37% in T2, T3, and T4 (P < 0.05), whereas that of the spleen was 62, 25 and 37% in T2, T3 and T4 (P < 0.05), respectively. Treatments 3 and 4 reduced SENAR counts (cfu/g) in the ceca from 4.3 log10 to 2.7 and 1.95 log10, respectively, compared to T2 (P < 0.05). The cecal count of SENAR was 1.6 log10 lower in T3 and 2.3 log10 lower in T4 compared to T2. Both yeast derived products reduced Salmonella in internal organs and the ceca of laying hens. Enzymatically-modified yeast (T4) was better than its intact counterpart (T3) in reducing Salmonella counts in the ceca.

SUMMARY: Two trials were conducted to evaluate the efficacy of a phytogenic, blend administered through the water, in reducing Salmonella infection in broiler chickens. The first trial was aimed to evaluate the potential efficacy of the phytogenic blend given at one dose, while the second compared 3 concentrations of the same blend. For the first trial, 240 one-day-old male broilers were obtained from a commercial hatchery and placed in battery cages. There were 10 replicates of 2 treatments: 1) infected control and 2) infected, water soluble phytogenic (0.100 g/L). Birds were challenged with 0.5 × 108 colony forming unit (CFU) nalidixic acid-resistant Salmonella typhimurium (ST) on d 1. Although not significant (P > 0.05), water-soluble treated birds had lower cecal S.T. concentrations compared with the control at 4 dpi (days postinfection; P = 0.06). No differences in cecal ST concentrations were observed at 7, 14, or 21 dpi. No significant differences in prevalence of ST in the ceca, livers, or spleens between the treatments were observed at any time point. Bird weight and FCR were significantly (P < 0.05) improved in water-soluble phytogenic treated birds. For the second trial, 212 one-day-old broilers were obtained from a commercial hatchery and placed in battery cages. There were 5 replicates of 5 treatments: 1) uninfected, untreated 2) infected, untreated, 3) infected, 0.075 g/L water-soluble phytogenic, 4) infected, 0.100 g/L water-soluble phytogenic, and 5) 0.125 g/L water-soluble phytogenic. On D 3, birds were infected with 7.8×108 CFU S. Enteritidis (SE). Two dpi there were no significant (P > 0.05) differences in cecal S.E. between the treatments. On 5 and 11 dpi, the birds given water-soluble phytogenic had significantly (P < 0.05) lower cecal S.E. compared with the infected controls. No significant differences (P > 0.05) in bird weights or FCR between treatments were observed. In conclusion, the addition of water-soluble phytogenic to the drinking water reduced Salmonella infection in broilers challenged with Salmonella.

ABSTRACT: Genetic selection for increased growth rate in broilers makes feed restriction programs such as skip-a-day (SAD) feeding, for broiler breeders essential to managing body weight, flock uniformity, and reproductive performance. The objective of this experiment was to compare intestinal development, weight gain of breeder pullets, and reproductive performance (22–45 wk) when fed a high fiber diet (3.8% crude fiber) on either an every-day (ED) or SAD basis during rearing. The same developer ration and feed amounts were fed to both treatments. Day-old Ross 708 pullet chicks (n = 912) were randomly distributed into 4 floor pens (n = 228/pen, 2 pens/treatment). At 20 wk of age all birds were weighed, and the coefficient of variation (CV) and average body weight was calculated for each treatment. Birds were then distributed into 10 lay pens (n = 35 birds/pen, 5 pens/treatment) at 21.5 wk of age. Light was increased from 8 h to 15.25 h at move to the lay facility, and all birds were daily fed for the remainder of the study. Data were analyzed by SAS SLICE using a significance level of P ≤ 0.05. During lay, 25% of the birds from each treatment were weighed weekly to adjust feed and monitor body weight. At 21 wk the ED fed pullets were more uniform (P = 0.0007) than the SAD fed pullets. Eggs were collected daily and set for hatch every 4 wk from 28 to 42 wk of age. No significant difference in the hatch data were observed. The ED fed birds achieved first egg at 166 d of age while the SAD fed birds achieved first egg at 173 d of age. Specific gravity was measured every 2 wk from 30 to 40 wk, with ED reared birds having better overall eggshell quality (P = 0.02) and greater egg weight (P < 0.0001) than those fed SAD. Feeding a high fiber diet on an ED basis during rearing, improved body weight uniformity in rearing, encouraged early lay, improved eggshell quality and increased egg weight.

A study was conducted to evaluate the effect of dietary 25-hydroxyvitamin D3 (25OHD) on pullet and egg-laying hen growth performance, egg production, and egg quality. Three hundred and ninety 1-day-old Hy-Line W36 pullets were randomly allocated to 3 treatments with 10 replicated cages and 13 birds per cage. Dietary treatments were vitamin D3 at 2,760 IU/kg (D); vitamin D3 at 5,520 IU/kg (DD), and vitamin D3 at 2,760 IU/kg plus 25OHD at 2,760 IU (69 μg)/kg (25D). Body weight and feed intake were recorded at the end of each stage: starter 1 (0–3 wk), starter 2 (4–6 wk), grower (7–12 wk), developer (13–15 wk), prelay (15–17 wk), peaking (18–38 wk), layer 2 (39–48 wk), layer 3 (49–60 wk), layer 4 (61–75 wk), and layer 5 (76–95 wk). Egg production was recorded daily. Egg quality was evaluated every 8 wk starting from 25 wk. There was no difference in growth performance during the rearing period (0–17 wk). In the laying period (18–95 wk), DD showed lower feed intake at layer 2, but higher intake at layer 3 along with lower hen day production (HDP) from 22 to 48 wk compared to the other treatments. During the same period, the DD group laid smaller eggs with higher specific gravity and shell thickness compared with the other treatments or D alone at 40 wk, which may be partly due to the lower body weight. In contrast, 25D had better feed conversion ratio (feed intake per dozen of eggs) at layer 2, and higher overall (22–60 wk) HDP compared with DD. For the egg quality analysis, at 25 and 33 wk, both DD and 25D had higher Haugh unit compared with D. However, 25OHD has no effects on eggshell quality during the entire production period and no beneficial effects on egg production during the later laying period (after 60 wk). In summary, long-term and early supplementation of 25OHD has positive effects on egg production and egg quality, and the beneficial effects were mainly observed during the early laying stage.

This study evaluated the effects of dietary fiber provided as purified cellulose (Solka-Floc, SF) or soybean hulls (SH) on the growth performance, organ growth, intestinal histomorphology, and nutrient digestibility. A total of 420 one-day-old Cobb male broilers were randomly assigned to 7 dietary treatments and reared to 20 d of age in battery cages (n = 6 replicates per treatment). The control group consisted of a simple corn and soybean-meal–based diet. The 6 fiber treatments had increasing amounts of SF or SH to achieve 4, 6, and 8% crude fiber (CF). Chromium oxide was added as an indigestible marker at 0.3% in all treatment diets from 14 to 20 d for nutrient digestibility analyses. Weights for digestive organs were taken on day 20. Growth performance was measured weekly. Birds fed 4% SH diet had a higher day 20 body weight gain than those fed 8% CF regardless of fiber sources (P = 0.0118). Control and 4% SH groups had the best feed conversion ratio among the treatments at 7, 14, and 20 d (P

Egg-laying hens have a unique bone development pattern due to the medullary bone formation and high bone turnover rate. The role of long-term supplementation of an intermediate form of vitamin D3, 25-hydroxyvitamin D3 (25OHD), on skeletal development of pullets and laying hens is not well established. Exploring its effects on layer bone development will help develop a strategy for preventing laying hen osteoporosis. The purpose of this study was to investigate the role of long-term supplementation of 25OHD in layer diets on bone 3-dimensional structural development. A total of 390 1-day-old Hy-Line W36 pullets were randomly allocated to 3 treatments with 10 replicate cages and 13 birds/cage. Dietary treatments were 1) vitamin D3 at 2,760 IU/kg, 2) vitamin D3 at 5,520 IU/kg, and 3) vitamin D3 at 2,760 IU/kg plus 25OHD at 2,760 IU (69 μg)/kg. The level of 25OHD in the serum was tested throughout the whole experimental period (0–95 wk). Bone growth rate (BGR) was measured at 10 wk using a calcein injection technique. Femurs were scanned using Micro-CT for 3D structural analysis, and the whole-body composition analysis was performed using a dual-energy x-ray absorptiometry method at 17, 60, and 95 wk. Dietary supplementation of 25OHD significantly increased 25OHD level in the serum from 0 to 95 wk. During the rearing period (0–17 wk), 25OHD increased BGR, cortical tissue volume, and bone marrow area at 17 wk, simultaneously. 25OHD created more pores in cortical bone, which resulted in a lower cortical bone mineral density (BMD) but without alerting bone mineral content (BMC). This effect allowed more space for mineral deposition in bones during the later egg-laying period. At 60 wk, the 25OHD group had significantly greater BMD, which led to the highest total BMC, cortical volume, and trabecular bone connectivity. At 95 wk, the birds fed 25OHD had significantly higher cortical bone volume and lower porosity. The 25OHD group also had higher total BMD and medullary bone volume but a lower BMC and volume of trabecular bone than vitamin D3 or double dosage vitamin D3 treatment. This indicated that the bone resorption rate was lower in cortical bone than that in trabecular bone in the late laying period. In conclusion, supplementation with dietary 25OHD could stimulate bone growth and increase bone volume in pullets to provide more space for mineral deposition during the laying period with positive effects on laying hen bone quality.

The application of micro-CT in small animal research, especially on bone health, has risen exponentially in recent years. However, its application in egg-laying hen bone analysis was still limited. This review introduces the technical aspects of micro-CT in egg-laying hen bone analysis, especially with the medullary bones presented in the cavity. In order to acquate application of micro-CT for laying hen bone research, image acquisition, reconstruction, and analysis settings need to be adjusted properly. The key difference regarding the application of micro-CT in laying hen bone compared to other small animals such as mice and rats was the larger bone size and more complex structures of medullary and trabecular bones. In order to analyze the details of laying hen bone structures, the volume of interest for laying hen should be selected at a region where all 3 bones are present (critical, trabecular, and medullary bone). Owing to the complexity of bone structures, the conventional techniques are not useful to distinguish the trabecular bone and medullary bone in laying hens accurately. In the current review, an automated segmentation algorithm is described to allow researchers to segment bone compartments without human bias. The algorithm is designed according to the morphology difference of medullary bones compared to trabecular and cortical bones. In this procedure, the loosely woven bones were separated by applying dual thresholds. The medullary calcium chunks were separated by opening or closing procedures, where we defined the diameter of medullary chunks being higher than the trabecular bone thickness as a separation trait. The application of micro-CT in laying hen bone health assessment will significantly expand our understanding of chicken bone physiology and osteoporosis, contributing to improve welfare in laying hens.

A study was conducted to investigate the effects of total sulfur amino acid (TSAA) levels on performance and bone metabolism in pullets under heat stress (HS). Hy-Line W36 day-old pullets (n = 216) were randomly distributed in 3 dietary treatments (70, 85, and 100% of TSAA), with 6 replicates of 12 birds. The treatments were defined as percentages of the TSAA level recommendation (100, 85, and 70%), and 85 and 100% of TSAA were obtained by adding L-Methionine to the basal deficient diet (70% of TSAA). The birds were raised under HS (35°C/7 h/D) from 1 to 18 wk. At 6, 12, and 18 wk, growth performance was measured. At 12 and 18 wk, bone weight, ash, collagenous (ColP), and noncollagenous proteins (NColP), tissue volume (TV), bone mineral content (BMC), and mineral density from total, cortical, and trabecular bones were evaluated. The means were subjected to ANOVA and, when significant (P ≤ 0.05), were compared by Dunnett's test. Regression analyses were performed to evaluate trends of TSAA dose response. Overall, birds fed 70% of TSAA showed poor growth and feed efficiency compared with other groups. Additionally, in at least 1 phase, birds fed 70% of TSAA showed lower bone ash, NColP, total BMC, and TV and higher ColP than the other treatments, whereas the cortical and trabecular TV and BMC were lower than 100% of TSAA (P 0.83). In conclusion, the use of a TSAA-deficient diet resulted in poor performance and delayed bone development. Additionally, the use of 100% of TSAA led to better initial structural bone development than 85% of TSAA. Therefore, the TSAA level recommended by the primary breeder guideline was enough to support growth and bone quality under HS, suggesting that HS does not alter TSAA requirement in pullets.

This study evaluated the effects of total sulfur amino acid (TSAA) levels on the performance and intestinal health of broilers challenged with Eimeria spp. A total of 432 one-day-old off-sex Cobb 500 male chicks were randomly assigned to a 3 × 2 factorial arrangement (6 replicates/12 birds), with diets and Eimeria challenge as the main factors. The diets were as follows: 70% (no methionine [Met] supplementation), 85, and 100% TSAA, supplemented with L-Met. At day 14, the challenged birds (n = 216) were orally gavaged with a pool of Eimeria acervulina, Eimeria maxima, and Eimeria tenella sporulated oocysts, and the unchallenged birds (n = 216) received water. At 6 and 12 D post inoculation (dpi), performance and intestinal health were evaluated. The challenge, regardless of diets, significantly impaired the performance, intestinal villi height, villus-to-crypt ratio, and ileal digestibility of dry matter, energy, and crude protein (CP) and modulated the tight junction protein (TJP) expression throughout the experiment. Moreover, the superoxide dismutase activity was increased, whereas the reduced glutathione (GSH)-to-oxidized glutathione (GSSG) ratio was decreased by the challenge at 6 dpi. Regardless of the challenge, the 70% TSAA diet reduced the body weight and feed intake in all phases, whereas the ileal digestibility of CP was higher in birds fed with the 70% TSAA diet than in those fed with the 100% TSAA diet at 6 dpi. No major differences were observed among the diets with regard to the intestinal histomorphology and TJP expression, and birds fed with the 100% TSAA diet had the highest GSH concentration at 12 dpi. Few interactions were observed, and the Met supplementation counteracted the negative effects of the Eimeria challenge on GSH concentration when 85 and 100% of TSAA levels were reached. Overall, the Eimeria challenge had a negative impact on growth and intestinal health. Moreover, the supplementation of L-Met until either 85 or 100% of TSAA levels were reached was enough to assure good performance and intestinal health in birds challenged or not challenged with Eimeria spp.

Summary: An experiment was conducted to evaluate effects of dietary energy level and 1,3-diacylglycerol (DAG) on growth performance and carcass characteristics in broilers. A 2 × 2 completely randomized factorial arrangement was used in this study with Cobb standard or reduced levels of dietary energy and inclusion of DAG at 0 or 0.1%. For the standard-energy group, ME was formulated to 3,000, 3,100, and 3,150 kcal/kg for starter (day 0–7), grower (day 8–21), and finisher (day 22–42) periods, respectively. In the reduced-energy diet, ME was reduced by 75 kcal/kg for each period. A total of 640 1-day-old Cobb500 male broilers were randomly placed into 4 treatments with 8 replicate pens of 20 birds each. At day 43, 8 birds from each pen were selected for carcass yield. A reduction of dietary energy decreased (P

SUMMARY: Heat stress (HS) negatively impacts animal production worldwide, being an economic and welfare issue. In poultry, HS was shown to reduce feed intake and increase mineral excretion, suggesting a marginal mineral deficiency. The objective was to assess the response of Azomite, a dacitic (rhyolitic) tuff breccia (DTB), on performance, antioxidant system, gut health, inflammation, and bone characteristics in broilers under a chronic cyclic HS challenge. A total of 1,280 one-day-old male broiler chicks (Cobb 500) were distributed in a randomized complete block design with four dietary treatments, 16 replicates of 20 birds. The treatments consisted of control (0% of DTB), and diets with 0.125, 0.25, and 0.5% of DTB added. Data were analyzed by Mixed procedure (SAS) with linear and quadratic contrasts for dose-response. Using 0.25% DTB tended to improve daily gain from 28 to 42 d (P = 0.06), and improved feed efficiency from 28 to 42 (P = 0.04) and 0 to 42 d (P = 0.02) compared to 0.5% DTB. Crude protein and phosphorus digestibility linearly increased with DTB supplementation (P < 0.01), and calcium digestibility was higher in 0.125 and 0.5% than 0.25% DTB (P < 0.01). Ileal crypt depth was greater in 0.25% than control and 0.125% DTB (P = 0.01), whereas ileal villus:crypt ratio and GSH-Px were higher in control than 0.25% DTB (P < 0.05). Bone mineral content, mineral density, and area were improved when birds were supplied with 0.125 and 0.25% DTB. The results showed the potential of DTB in improving feed efficiency, bone characteristics, and crude protein, Ca, and P digestibility in birds subjected to chronic cyclic HS.

ABSTRACT: This study was performed to investigate the effect of feeding Brassica spp. including full-fat rapeseed, canola meal, and allyl isothiocyanate (AITC) to broiler chicken challenged with E. maxima. A total of 576 one-day old male broiler chicks were completely randomized to 8 treatments with 6 replicated cages and 12 birds per cage. The treatment diets consisted of nonchallenge control (NC, corn-SBM based diet), challenge control (CC), 10% rapeseed (10RS), 30% rapeseed (30RS), 20% canola (20CLM), 40% canola (40CLM), 500 ppm AITC (500AITC), and 1,000 ppm AITC (1000AITC). At d 14, all birds were challenged, except NC group, with a subclinical dose of E. maxima. Intestinal permeability was conducted on 5 d post-infection (dpi) and for oocyst shedding 5 to 6 dpi feces were pooled and collected. On 6 dpi, growth performance, lesion score, histomorphology, and gene expression were measured. The growth performance result showed that 10RS and 30RS groups had lower BW, BWG, FI, and higher FCR (P < 0.0001). During the challenge and overall periods, NC group had highest BW, BWG, and FI, and lowest FCR. The inclusion of canola meal showed lower performance during prechallenge period but was able to catch up BWG during challenge period. The AITC levels showed similar growth performance to CC group. Intestinal permeability for 20CLM, 40CLM, 500AITC and 1000AITC was similar to NC group, whereas CC, 10RS, and 30RS had higher permeability compared to NC (P < 0.0001). Oocyst shedding was significantly lower for 40CLM and NC, whereas all other treatments had higher oocyst shedding (P < 0.0001). All the challenged treatment groups had higher lesion score and microscore than NC (P < 0.0001). Histomorphology data showed that jejunum villus height (VH) for 1000AITC was similar to NC group, whereas CC group had the lowest VH (P = 0.01). The 30RS group had lower VH: crypt depth (CD) ratio in the jejunum and ileum. The gene expression at 6 dpi for claudin1, occludin, IL2, IL6, GLUT5, EAAT, BoAT, and LAT1 was significantly changed among the treatments. The results suggest that 30RS retards growth performance and deteriorate gut health during coccidiosis and should not be fed to chicken during the starter phase. Canola meal showed decline in growth prechallenge but maintained growth and intestinal health during the challenge period at 40% inclusion. AITC at 1,000 ppm showed similar growth as control group, but with improved gut health during the challenge period. Canola meal could be a good alternative to SBM especially during coccidiosis, whereas AITC needs to be tested vigorously in animal feeding regime.

ABSTRACT: Poultry is the major sources of foodborne salmonellosis. Antibiotic resistance and a surge in zoonotic diseases warrant the use of natural alternatives. Glucosinolates (GLs) are naturally occurring antimicrobial compounds in rapeseed and canola. This study investigated the effect of feeding rapeseed, canola meal, and allyl isothiocyanate (AITC; Brassica secondary metabolites) on growth performance (GP), gut health, and the potential antimicrobial activity against nalidixic acid-resistant Salmonella Typhimurium (STNR) in chickens. A total of 640 one-day-old male Cobb 500 broilers were randomly allocated to 8 treatments with 8 replicated cages and 10 birds per cage. Dietary treatments were nonchallenge control (NC, corn-SBM based), challenge (Salmonella) control (CC), 10% rapeseed (10RS), 30% rapeseed (30RS), 20% canola meal (20CLM), 40% canola meal (40CLM), 500 ppm AITC (500AITC), and 1,500 ppm AITC (1500AITC). On d 1, all the birds except NC were orally challenged with STNR (7 log CFU/bird). The chickens were reared for 21 d, and their FI and BW were recorded weekly. Salmonella cecal colonization and fecal shedding were quantified, whereas organ translocation (OT) of STNR to the spleen, liver, and kidney was tested on 0, 3, 6, 13, and 20-d postchallenge (dpc). Data were subjected to one-way ANOVA, and the means were separated by Duncan's test, except mortality and OT data analyzed after transformation by square root of (n +1) (P < 0.05). Overall, feeding 30RS resulted in reduced BW (P = 0.003), BWG (P = 0.003), and FI (P = 0.001) compared to CC, 500AITC, and 1500AITC. Similarly, feeding 20CLM resulted in lower BW and BWG compared to CC (P < 0.05) and increased FCR compared to 1500AITC (P = 0.03). Feeding CC resulted in higher mortality compared to NC and 30RS (P = 0.03). Cecal colonization of STNR was reduced (P < 0.0001) for 30RS on 6 dpc and 500AITC on 6 and 13 dpc (P < 0.0001). Although no difference in gut permeability was observed 6 dpc (P > 0.05), OT of STNR population was the highest for CC in the spleen (P = 0.05). In the liver, 10RS showed reduced OT compared to 20CLM on 13 dpc (P = 0.03), whereas 30RS showed the lowest OT on 6 dpc in the kidney. Fecal shedding was lowest for 30RS on 6 dpc (P = 0.004). Histomorphology showed 30RS had the highest duodenum (P = 0.01) and jejunum (P = 0.02) villus height (VH) and VH to crypt depth (CD) ratio compared to the other treatments, whereas 1500AITC showed similar results to 30RS. Both 30RS and 1500AITC contained comparatively higher functional GL metabolites and were able to maintain gut health. Including higher levels of rapeseed or AITC in poultry feed can reduce Salmonella colonization in the feces and their translocation to other organs.

ABSTRACT: The aim of this study was to evaluate the effect fiber type, particle size, and inclusion level on the performance parameters, intestinal development and gene expression in broiler chickens. A total of 648 one-day old Cobb male broilers were randomly assigned to a control diet and 8 other dietary treatments divided in 2 fiber types (cellulose vs. soyhulls), 2 particle sizes (100 and 600 µm), and 2 inclusion levels (4 and 8% crude fiber). Birds were reared to 21 days of age in battery cages (n = 6 replicates). Growth performance parameters and intestinal viscosity were measured on da 7, 14, and 21. On d 14 and 21, digestive organ weights were recorded for analyses of organ growth. On d 21, intestinal samples were taken for analyses of histology, and jejunal mucosas were collected for analyses of nutrient transporters. Data were analyzed as a 2 × 2 × 2 factorial design using JMP 2021. Treatments were compared against the control group using one-way analysis of variance, whereas the main effect interactions were evaluated as a factorial excluding the control group to be able to assess the effect of the independent variables without the variability introduced by the control group. The groups fed 8% crude fiber from cellulose (8% CL) had the lowest weight gain regardless of the particle size (P < 0.01). The control group had the highest feed intake among the treatments (P < 0.01). The groups fed 8% crude fiber from soyhulls (8% SH) with a coarse particle size had the heaviest relative gizzard weight among the treatments (P = 0.045). The groups fed 8% SH had the heaviest small intestine weights regardless of the particle size (P = 0.009). No differences were observed in the relative weights of the ceca. The highest viscosity was observed in the group fed 8% SH with a fine particle size (P < 0.001). The group fed 4% SH with a coarse particle size had the longest duodenal villus (P < 0.001). The shortest jejunal villus height was observed in the group fed 8% CL with a fine particle size (P < 0.001). Ileal villus was highest in the groups fed high CL levels regardless of the particle size (P < 0.001). The highest digestibility of dry matter was observed in the group 4% SH with fine particle (P = 0.017). The group 4% CL with fine particle had the highest digestibility of crude protein (P = 0.033). The highest expression of peptide transporter 1 was observed in the group fed 8% CL with a coarse particle size (P = 0.008). In conclusion, fiber type, particle size, and inclusion levels are important factors in the regulation of intestinal morphology, viscosity, nutrient transporters, and growth performance.

ABSTRACT: The objective of this study was to evaluate 2 varieties of almond hulls (prime and California type hulls) as an alternative feed ingredient on the performance, egg quality, nutrient digestibility, and body composition using a total of 100 23-week-old Hy-Line W36 hens. Treatments consisted of a control diet based on corn and soybean meal; T2 and T3 were formulated to contain 7.5 and 15% of prime hulls; and T4 and T5 contained 7.5 and 15% of California type hulls. Inclusion of prime hulls and California type hulls had no effects on feed intake, egg laying rate, and feed conversion ratio, but California type hulls at 7.5% decreased (P < 0.001) body weight gain compared to the control. Prime hulls at 7.5% and California type hulls at both levels improved (P ≤ 0.022) AMEn and N digestibility. Both prime hulls and California type hulls had no effects on egg size, specific gravity, Haugh unit, and percentages of yolk, albumen and shell, but yolk color appeared greener and less yellow (P ≤ 0.009) by prime hulls and less yellow (P = 0.001) by California type hulls. For body composition, prime hulls and California type hulls at both levels lowered (P ≤ 0.017) body fat, and California type hulls at 7.5% decreased (P = 0.001) lean weight. In summary, inclusion of prime hulls and California type hulls up to 15% had no negative effect on egg production and egg quality while reduced the body fat percentage and mass.

Summary: Aluminum doped magnetite (Fe3O4) magnetic nanoparticle (MNP) has been used as an effective sorbent to remove phosphorus (P) species in poultry processing wastewaters. It was found that spent MNP contains approximately 13% of P by weight. A study was conducted to evaluate the potential of using spent MNP as a P source. A total of 240 one-day-old male broilers were randomly allocated to four dietary treatments and six replicate each for 18 days. Treatments consisted of 1) positive control (PC) with 0.45% nonphytate-P (nPP); 2) negative control (NC) with a reduction of 0.15% nPP; 3) NC with additional 0.075% of P from magnetic nanoparticle (NC + 0.075% P-MNP); and 4) NC with additional 0.15% of P from magnetic nanoparticle (NC + 0.15% P-MNP). Body weight and feed intake were recorded at day 7, 14, and 18. Three birds were randomly selected from each cage for Dual-energy X-ray Absorptiometry (DXA) scanning at d18. The liver, heart, and spleen were collected and analyzed for mineral content. Ileal digesta were collected from the rest of the birds for P digestibility analysis. Data were subjected to SAS using one-way ANOVA model with GLM procedure. The birds fed with additions of 0.075% and 0.15% P from MNP had an increased (P = 0.017) body weight gain at d8 to d14 compared to those with NC diet. Significant lower (P ≤ 0.008) body mineral density and body mineral content were observed in the birds with NC diet compared to those with PC, NC + 0.075% P- magnetic nanoparticle, and NC + 0.15% P- magnetic nanoparticle diets. In addition, the birds with NC + 0.075% P- magnetic nanoparticle and NC + 0.15% P- magnetic nanoparticle had similar body mineral contents and body mineral densities compared to the PC-fed birds, indicating P from spent magnetic nanoparticle has incorporated into the bone mineralization. No significant differences were found between the treatments for mineral residues (Al and Fe) in liver, heart and spleen samples. The ileal P digestibility of dry matter and P was not influenced by the presence of magnetic nanoparticle in diets. In conclusion, 0.15% P from spent magnetic nanoparticle could be efficiently and safely used to replace the same amount P from dicalcium phosphate in the diets for broilers.

ABSTRACT: Broiler breeders are commonly feed restricted using some variation of skip-a-day feeding to prevent excessive body weight (BW) gain and poor flock uniformity that results in lower production levels. However, the level of feed restriction has increased leading to negative effects on broiler breeder welfare. Research needs to be conducted to evaluate alternative feeding programs to diminish the negative impact of restricted feeding on bird welfare. This research examined pullets that were fed soybean hulls (alternate day feeding, ATD) on the off day of a traditional skip-a-day feeding program in comparison to the standard skip-a-day program (SAD). The 2 dietary feeding treatments each had 3 replicate pens of 210 pullets each and were fed from wk 5 to 21 of age. Nitrogen-corrected true metabolizable energy and digestible amino acid coefficients of soybean hulls were determined. Body weight in the ATD feed program was significantly higher (P < 0.001) than the birds on the SAD feed program until 16 wk of age. Feed allocations for the SAD feeding program was increased at 11 wk of age to achieve similar BW prior to photo stimulation. The ATD feed program significantly improved BW uniformity of the birds for weeks 8, 12, 16, and 20. Hens fed on the SAD feed program had a lower mean egg production than the hens fed on the ATD program. There were significant differences on plasma corticosterone concentrations between the feeding days (24 or 48 h after feeding) in both feed programs. There was a shift in the behavior of the birds with significant differences in the feeding, foraging, and comfort behaviors between the feeding programs on the same feed day. Overall, feeding the ATD females soybean hulls on the off feed day improved the BW uniformity and egg production, but further research will be needed to determine potential differences in nutrient utilization or behavior of the pullets that positively impacted this flock performance.

ABSTRACT: Vitamin D is essential for the metabolism of calcium (Ca) and phosphorus (P) in birds. The objective of the study was to evaluate the effect of different isoforms of dietary vitamin D on Ca and P utilization, egg quality, and bone mineralization of laying hens. A total of 42 Lohmann white laying hens at 57 wk of age were randomly assigned to 7 dietary treatments for 6 wk. Dietary treatments were: 3,000 IU/kg Vit D3 as control, and control with additional 3,000 IU/kg 25-hydroxyvitamin D3 (T1), 9,000 IU/kg 25-hydroxyvitamin D3 (T2), 3,000 IU/kg vitamin D3 (T3), 9,000 IU/kg vitamin D3 (T4), 3,000 IU/kg of vitamin D2 (T5), or 9,000 IU/kg of vitamin D2 (T6). Egg production and egg quality were measured weekly. Fecal samples were collected at weeks 2 and 6 to measure Ca and P utilization. After 6 wk, the left tibia and femurs were collected to measure bone mineral density (BMD) and bone mineral content (BMC). A 1-way ANOVA with Tukey HSD means separation test was used for statistical analysis. There were no significant differences in egg production, egg quality, BMD, or BMC of tibia and femurs among the treatments (P > 0.05). T6 significantly reduced feed intake (P < 0.05). The apparent total tract digestibility (ATTD) of Ca was higher (P < 0.012) in treatments supplemented with additional vitamin D, irrespective of forms. The ATTD of P was higher (P < 0.0001) in T5 compared to the other treatments at both time points. The utilization of Ca and P by laying hens can be improved through the addition of different isoforms of vitamin D in diets. However, additional vitamin D supplementation to laying hens, regardless of forms, had no effect on either bone mineralization or measures of egg quality.

SUMMARY: The aim was to evaluate the partial replacement of synthetic DL-Methionine (DL-Met) by Herbal Methionine (H-Met) compared to DL-Met and L-Methionine (L-Met), and the effects on growth performance, fat metabolism, and serum biochemistry in broilers. A total of 600 1-d-old male Cobb500™ chicks (Cobb x Cobb) were distributed in a completely randomized design, five dietary treatments, six replicates of 20 birds each. Liquid L-Met was provided through carboys connected to the water line. Two positive control (PC) treatments were used, either connected to the regular water line (PC1) or to carboys (PC2). The treatments were: Negative control (NC—no Met supplementation); PC1 and 2 (100% DL-Met); 60% DL-Met + 40% H-Met through feed (TH-Met); and 50% DL-Met + 50% L-Met through water (TL-Met). At 10, 22, and 42 d body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) were determined. At day 21, serum and liver samples were used to evaluate serum biochemistry and the expression of genes related to fat metabolism, respectively. At 42 d, abdominal fat was weighed from 3 birds/replicate. In general, birds fed NC showed lower BWG, FI, higher FCR, and tended to have higher fat pad compared to the other treatments (P < 0.05). No differences were found for gene expression (P > 0.05). For serum biochemistry, Aspartate amino transferase (AST) level was higher in birds fed NC and TH-Met than in PC2 and TL-Met (P < 0.05). In conclusion, DL-Met can be partially replaced by H-Met without negatively affecting growth performance, fat metabolism, and serum biochemistry of broiler chickens.

Summary: An experiment was conducted to evaluate the effects of phytase and multicarbohydrase (MC) on growth performance, bone ash, and nutrient digestibility in broilers fed a nutritionally reduced diet. A total of 480 Cobb 500 male broilers were randomly allocated to 8 treatments with 6 replicates of 10 birds each. Experimental diets consisted of a positive control (PC); a negative control (NC) with the reduction of ME, CP, Ca, and nonphytate phosphorus by 75 kcal/kg, 1.5, 0.15, and 0.15%, respectively; NC plus phytase at 500, 1,000, or 1,500 FTU/kg as T3–T5; and further plus MC at 500 mg/kg as T6–T8. Results showed that during 0–18 d of age, feed conversion ratio (FCR) was increased (P

Summary: The objective of this study was to evaluate the effect of graded inclusion of almond hulls on growth performance, body composition, digestive tract weight, and liver antioxidant capacity of broilers. A total of 420 one-day-old Cobb male chicks was randomly allocated to 5 experimental treatments with 6 replicates of 14 birds each for 19 d of age. The five dietary treatments consisted of a corn-soybean meal control diet and 4 almond hull treatments containing 2.5, 5, 7.5, and 10% of almond hulls with 97.5, 95, 92.5, and 90% of the control diet, respectively. Feeding almond hulls at 10% reduced broiler body weight gain (P ≤ 0.048) and increased feed conversion ratio (FCR; P

Summary: The use of exogenous enzymes for poultry has been studied for years. However, there is still limited information on the effects of exogenous lipase supplementation on the growth performance of broilers fed with diets containing reduced nutritional levels. The objective was to investigate the effects of lipase supplementation on growth performance of broilers fed with diets containing different reduced ME, CP, and essential amino acids (EAA). One-day-old Cobb 500 male broilers (n = 480) were distributed in a randomized complete block design, with 4 dietary treatments and 6 replicates of 20 birds. The treatments were as follows: positive control (PC; formulated as per the breeder guideline), negative control (NC; reduction in nutrition levels by 100 kcal/kg in ME, by 1% in CP, and by 5% in EAA), PC diet supplemented with 100 g/t of lipase (PC + Lipase), and NC diet supplemented with 100 g/t of lipase (NC + Lipase). In general, the reduction in nutritional levels (NC) negatively affected body weight gain (BWG) and feed conversion ratio (FCR) compared with PC treatment (P < 0.05). The BWG and FCR were similar between the PC, PC + Lipase, and NC + Lipase groups and better than the NC group, from 1 to 14 d (P < 0.003). From 15 to 28 d, BWG was higher in the PC and PC + Lipase groups than in NC and NC + Lipase groups (P < 0.001), whereas FCR was lower in the PC and PC + Lipase groups than in the NC + Lipase group (P = 0.002). From 29 to 42 d, PC + Lipase and NC + Lipase treatments showed higher BWG than PC and NC treatments (P < 0.001). Most importantly, the use of lipase in NC diets from 1 to 42 d was able to ameliorate the negative effects of a low-nutrient diet, leading to results similar to the PC diet.

Summary: An experiment was conducted to evaluate the effects of dietary nonphytate phosphorus level and a novel corn-expressed phytase (GraINzyme, Agrivida Inc., Woburn, MA) supplementation on broiler growth performance and bone mineralization. Broilers were fed graded levels of nonphytate phosphorus from 0.20 to 0.44% increased by 0.06% and 4 levels of corn-expressed phytase (500; 1,500; 3,000; and 4,500 FTU/kg). Dicalcium phosphate was used as the reference for inorganic phosphorous. Increasing dietary nonphytate phosphorus level or supplementation of phytase linearly (P < 0.01) increased the bodyweight gain, feed intake, tibia fat–free dry weight, ash weight, ash percentage, and ash concentration. Feed conversion ratio was linearly (P < 0.01) improved as the dietary nonphytate phosphorus level was gradually increased. Graded nonphytate phosphorus levels were log-transformed and regressed against the bodyweight gain, tibia ash weight, ash percentage, and ash concentration for calculating the nonphytate phosphorus relative to the phytase efficacy. Both raw and standardized responses were regressed against dietary nonphytate phosphorus levels. Bodyweight gain was less sensitive than bone mineralization results. From the regression estimates using standardized responses, bodyweight gain was about 92% of tibia ash concentration in terms of sensitivity. The calculated nonphytate phosphorus relative to the equivalence for bodyweight gain, tibia ash weight, ash percentage, and ash concentration were 0.166, 0.158, 0.163, and 0.183%, respectively. Results suggest that the corn-expressed phytase is effectively released in the P form phytate and improves broiler growth performance and bone mineralization. Bone mineralization is a better indicator for the broiler response to dietary nonphytate phosphorus levels than bodyweight gain.

The objective of this study was to evaluate 2 types of almond hulls (prime hulls and California-type hulls) as alternative feed ingredients for broilers. A total of 560 one-day-old Cobb male chicks were randomly placed to 7 experimental treatments with 8 replicates of 10 birds each. Seven treatments consisted of a corn-soybean meal control diet and diets containing prime hulls or California-type hulls at 3, 6, and 9%. The nitrogen-corrected true metabolizable energy, crude protein, and crude fiber from prime hulls and California-type hulls were 1,624 and 1,514 kcal/kg, 4.8 and 5.0%, and 13.1 and 26.45%, respectively. During 0–19 d of age, the inclusion of the prime hulls at 3 levels had no significant effects on growth performance, but the California-type hulls at 9% increased feed intake (P = 0.02) and feed conversion ratio (P