Effects of phytase supplementation on production performance, egg and bone quality, plasma biochemistry and mineral excretion of layers fed varying levels of phosphorus.

Excessive fecal excretion of phosphorus (P) has increasingly become an environmental issue due to oversupply of P in layer rations, and thus it is imperative to minimize safety margins for P to ensure the sustainability of the egg industry. In this study, a 12-week feeding trial (22 to 34 weeks of age) was conducted to evaluate the effects of phytase supplementation on production performance, plasma biochemistry, egg and bone quality and P excretion of laying hens fed various levels of non-phytate P (NPP). Forty-eight Lohmann white laying hens were randomly allocated to one of six corn-soybean meal-oat-based diets: diets containing 2.0, 2.5 or 3.0 g/kg NPP without phytase, and diets containing 1.0, 1.5 or 2.0 g/kg NPP with phytase (1 000 U/kg diet) where phytase inclusion was expected to provide 1.0 g/kg NPP to laying hens, thus making the phytase-unsupplemented treatment served as a control for the phytase-supplemented treatment accordingly. Productive performance was recorded during the experimental period. Blood and egg samples were collected, and digestibility studies were conducted at weeks 6 and 12 of the experiment. Bone mineralization was evaluated at the end of the experiment. Egg weight and egg production, feed consumption, BW and feed conversion ratio of laying hens fed lower NPP diets supplemented with phytase were comparable to those of hens fed high NPP phytase-unsupplemented controls. Eggshell thickness, specific gravity, Haugh units, tibia bone mineral density, tibia ash percent, plasma P and other biochemical parameters were not significantly different among dietary treatments. Total P intake, excretion and retention were affected by diet (P < 0.001), but its deposition in eggs was not significantly different. Contrast analysis further showed that total P excretion of phytase present vs phytase absent was averagely reduced by 40.4 mg/hen per day (P < 0.01). Moreover, total P excretion was linearly (P < 0.01) reduced with lowering dietary NPP, and this relationship was similar regardless of whether phytase was supplemented or not. The results from this study indicated that NPP levels in laying hen diets could be reduced to 1.0 g/kg (excluding the portion of NPP released by phytase) with the inclusion of phytase, without negative effects on production performance and health of the hens, thereby diminishing P excretion into environment.

Influence of graded levels of meals from three lupin species on growth performance and nutrient digestibility in broiler chickens.

1. This study investigated the effect of different levels of seeds of lupin species (Lupinus angustifolius, Lupinus luteus and Lupinus albus) on broiler growth performance, nutrient digestibility and apparent metabolisable energy of poultry diets. 2. A control diet containing corn-soybean meal and test diets containing 50, 100, 150, 200 and 250 g/kg of three lupin species were fed to broiler chickens during a 35-day study period. There were 10 replicate cages of 8 broiler chickens per treatment. 3. Growth performance of the birds fed with yellow and white lupin diets was found to be similar to that of the birds in the control group. The use of narrow-leaved lupin seeds in the diet quadratically decreased the body weight gain of birds and increased feed conversion ratio during all the experimental periods (0-14, 15-35 and overall 0-35 days of age). 4. A significant interaction between lupin species and their inclusion levels for apparent metabolisable energy and apparent ileal digestibility of starch was observed, showing a negative effect of increasing levels of narrow-leaved lupin. Pearson correlation coefficients demonstrated that the presence of raffinose and non-starch polysaccharides is a key factor affecting the nutritive value of lupin, 5. Yellow and white lupins could be utilised as an alternative ingredient for soybean meal in the diet of broiler chickens without any adverse effects on growth performance. The narrow-leaved counterpart diet reduced broiler performance, and hence did not provide a satisfactory outcome.

Assessment of the minimal available phosphorus needs of laying hens: Implications for phosphorus management strategies.

The oversupply of dietary phosphorus (P) leads to increased feed costs and discharge of excessive P to the environment, thus directly impacting the sustainability of egg production practices. The present study was conducted to better define the minimal available P needs of laying hens. Fifty-six Lohmann white laying hens were individually caged and fed one of 7 diets with graded levels of available P (0.15, 0.20, 0.25, 0.30, 0.35, 0.40, or 0.45%) for 12 weeks. Records were maintained for body weight, feed intake, and egg production during the experimental period. Blood and egg samples were collected and digestibility studies conducted at wk 6 and 12 of the experiment. At the end of the experiment, tibia characteristics and expression of the P transporters in the small intestine and kidney were determined. Lowering dietary available P from 0.45 to 0.15% generally reduced plasma P concentrations (P < 0.01), but hen productive performance, plasma calcium, parathyroid hormone and other constituents, tibia bone mineral density and content, tibia ash percentage, and mRNA abundance of the small intestine, and kidney type II sodium/phosphate cotransporter were not different among treatments. Specific gravity and eggshell thickness tended to increase with reducing dietary P (P < 0.05). Total P intake, excretion, and retention net amount decreased (P < 0.01) with reducing dietary P, but its retention rate (of intake) remained unchanged. Furthermore, changing dietary P did not affect calcium retention rate and net deposition of total P and calcium in eggs. These data indicate that reducing dietary available P up to 0.15% is adequate to maintain health and performance of layers. As such, this minimal available P estimate should serve as a benchmark for the assessment of P contents of commercial laying hen rations, with the goal of enhancing the sustainability of egg production.

Assessment of the minimal available phosphorus needs of pullets during the pre-laying period.

Dietary phosphorus (P) oversupply is costly to the poultry industry and represents a point source of excessive P discharge to the environment via manure application to soils. The current study was conducted to investigate the effects of dietary available P (AP) level on growth performance, plasma biochemistry, bone characteristics, and P flow in order to assess minimal AP needs of pullets during the pre-lay period. A total of 192 Lohmann pullet chicks were randomly allocated to one of 4 treatments with 8 replicate cages of 6 birds per cage. The pullets of Low (L; the lowest AP regimen) were fed diets in a sequence of 0.200, 0.175, and 0.150% AP for the age period of 0 to 4 wk, 4 to 8 wk, and 8 to 16 wk, respectively. The AP level was increased by an increment of 0.1% in each phase in Low-Medium (LM), Medium-High (MH) and High (H), thus making H (control) consisting of 0.500, 0.475, and 0.450% AP. Overall, there were no main effects of treatment on body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR). However, compared with the H treatment, BWG or FI of the L treatment was lower during the first 8 wk post-hatch, but became comparable or higher over the last 8 wk (P < 0.05); FCR of L birds was greater over wk 0 to 4 but became smaller over wk 8 to 16 (P < 0.05). Plasma P was lower in L than H treatments at wk 8 but turned comparable at wk 16 (P < 0.001). Bone characteristics were not different for pullets fed various AP regimens. Total P intake and excretion were reduced with lowering dietary AP (P < 0.001), but its retention percent was not affected. The results indicated that the lowest AP regimen (0.200-0.175-0.150%) in the current study was adequate to support healthy growth and development of pre-lay pullets, while reducing P excretion in manure.

Effects of canola meal source on the standardized ileal digestible amino acids and apparent metabolizable energy contents for broiler chickens.

Two studies were conducted to determine the effect of canola meal source on the standardized ileal digestible amino acids (AA) and nitrogen-corrected apparent metabolizable energy (AMEn) contents of canola meal (CM) from 6 processing plants in Canada. Two plants provided CM in both mash and pellet forms, while the other 4 provided CM in mash form only, giving a total of 8 samples. In the standardized ileal digestibility (SID) assay, 280 birds were housed 7 per cage and fed a commercial starter diet from 1 to 14 d of age followed by the test diets from 15 to 21 d. Diets were formulated to contain CM as the only source of protein. Chromic oxide was included in all diets as an indigestible marker. Diets were randomly assigned to 5 cages of 7 birds. On d 21, birds were euthanized by CO2 asphyxiation and digesta samples were collected from the terminal ileum for SID of AA. The SID values were calculated using ileal endogenous AA losses determination. In the AMEn assay, 330 birds were housed 6 per cage and fed a commercial starter diet from 1 to 14 d of age followed by the experimental diets from 15 to 19 d. The 8 experimental diets contained 30% of CM and 70% of a corn-soybean meal-based diet. There were differences (P < 0.05) among CM samples in the standardized ileal digestible content of all AA. Standardized ileal digestible contents of Arg, Lys, Met, and Thr averaged 2.17, 1.74, 0.53, and 1.03%, respectively. Pelleting reduced (P < 0.05) the standardized ileal digestible content of all AA in CM from one of the plants. There were differences (P<0.05) among CM samples in the AMEn contents with values ranging from 1,590 to 2,041 kcal/kg DM. In conclusion, there was effect of CM source on the standardized ileal digestible AA and AMEn contents. Regression equations for predicting standardized ileal digestible contents of selected AA from a simple measure of acid detergent fiber (ADF) were developed.

Standardized ileal digestible amino acid contents of canola meal from Canadian crushing plants for growing pigs.

Studies have shown that there are variations in the chemical and nutritive composition of canola meal (CM) produced in Canada, some of which may result from differences among the canola seed crushing plants. Therefore, it is necessary to determine the variability in the nutritive value of CM as its end users desire increased meal consistency and more information on any potential variability in AA digestibility. Thus, 18 ileal cannulated barrows (average initial BW = 23.3 kg) were used to determine the apparent (AID) and standardized (SID) ileal digestibility of N and AA and standardized ileal digestible N and AA contents in CM from 6 processing plants in Canada. Two processing plants provided CM in both mash and pellet forms, whereas the other 4 provided it only in mash form, giving a total of 8 CM samples. The barrows were fed 9 cornstarch-based diets. The first 8 diets were formulated to contain the CM samples as the only source of AA. The ninth diet was a casein-cornstarch diet to determine ileal endogenous AA losses. All diets contained 0.3% titanium dioxide as an indigestible marker. Pigs were housed individually in pens and were fed the 9 diets in a completely randomized design for 3 periods to give 6 pigs per diet. Each experimental period lasted for 7 d, consisting of 5 d of adaptation and 2 d of ileal digesta collection at 2-h intervals from 0800 to 2000 h on d 6 and 7. There was an effect ( < 0.05) of CM source on 1) the AID of N, Met, Cys, Thr, Val, Gly, and Ser; 2) the SID of N, Met, and Cys; and 3) the standardized ileal digestible content of all AA. Pelleting reduced ( < 0.05) the standardized ileal digestible content of Arg, Ile, Glu, and Gly in 1 of the CM samples tested and of all AA except His in the other CM sample. The SID values for Arg, Lys, Met, and Thr averaged 87.2%, 78.2%, 84.5%, and 74.1%, respectively. The standardized ileal digestible contents of Arg, Lys, Met, and Thr averaged 2.10%, 1.71%, 0.50%, and 1.01%, respectively. In conclusion, there were variations in the AID, SID, and standardized ileal digestible AA contents of CM among crushing plants in Canada.

Ileal Amino Acid Digestibility of Broken Rice Fed to Postweaned Piglets with or without Multicarbohydrase and Phytase Supplementation.

Most of amino acid (AA) digestibility values for feed ingredients are obtained using pigs cannulated in the distal ileum. The ileal-cannulated pig model uses pigs older than six weeks due to difficulties related to implanting the T-cannula in distal ileum of younger pigs and complications during the post-surgical recovery. However, to properly formulate the diet of weaned pigs, the nutritive value of feed ingredients should be determined with younger pigs. Thus, 25 weaned pigs were used to determine the apparent total tract digestibility (ATTD) of nutrients, energy, and apparent ileal digestibility (AID) and standardized ileal digestibility (SID) ileal AA digestibility of broken rice (BR), with or without multicarbohydrase (MC) and phytase (Phy) supplementation. Piglets were weaned at 23 d of age and individually housed in digestibility cages until 45 d of age. The trial consisted of 7 d of adaptation to the experimental diets and 3 d of excreta (feces and urine) collection. Ileal digesta was collected at slaughter (about 6 weeks of age). A completely randomized experimental design was used to determine the effects of MC and Phy. Reference diets (RD, 5% casein) was replaced by 30% of BR with or without MC, Phy, or MC+Phy. The RD was used to quantify endogenous AA losses. BR with Phy supplied had increased the ATTD of dry matter (p<0.05) and SID of histidine (p = 0.05), arginine, leucine, lysine, valine, alanine, and proline (p<0.05). BR with MC had been increased digestible energy and protein and SID for histidine (p<0.05). There was no interaction between Phy and MC on the BR nutrient digestibilities. Standardized amino acid digestibilities of BR, without enzymes, were lower than those values reported in the literature. The MC and Phy improved the digestibility of some nutrients and energy of BR in post-weaned piglet diets.

Effect of yeast-derived products and distillers dried grains with solubles (DDGS) on growth performance and local innate immune response of broiler chickens challenged with Clostridium perfringens.

This study evaluated the effect of yeast-derived products on growth performance, gut lesion score, intestinal population of Clostridium perfringens, and local innate immunity of broiler chickens challenged with C. perfringens. One-day-old broiler chickens were randomly assigned to eight dietary treatments providing six replicate pens of 55 birds each per treatment. Dietary treatments consisted of Control diets without and with C. perfringens challenge, and diets containing bacitracin methylene disalicylate (BMD, 55 g/tonne), nucleotides (150 g/tonne), yeast cell wall (YCW, 300 g/tonne), and a commercial product Maxi-Gen Plus (1 kg/tonne) fed to chickens challenged with C. perfringens. Diets containing 10% distillers dried grains with solubles without and with C. perfringens challenge were also used. Birds were orally challenged with C. perfringens (10(8) colony-forming units (cfu)/bird) on day 14. On day 21, intestinal samples were collected for gene expression analysis. Pathogen challenge significantly (P < 0.05) impaired feed intake, body weight gain, and feed conversion ratio (FCR) shortly after the challenge (14-21 days). Increased C. perfringens counts and intestinal lesion scores were observed for challenged birds except the BMD-containing diet. Over the entire trial (1-35 days), no difference in growth performance was observed except the BMD diet which improved FCR over the Control, challenged group. Birds receiving nucleotides showed increased expression of toll-like receptors and cytokines interleukin (IL)-4 and IL-18 compared to the Control, challenged group. Expression of macrophage mannose receptor and IL-18 was upregulated in birds receiving YCW. Increased expression of cytokines and receptors involved in innate immunity in broilers receiving nucleotides and YCW suggests the immunomodulatory properties of these products under pathogen challenge conditions.

Effect of yeast-derived products and distillers dried grains with solubles (DDGS) on growth performance, gut morphology, and gene expression of pattern recognition receptors and cytokines in broiler chickens.

An experiment was carried out to investigate the effect of yeast-derived products and distillers' dried grains with solubles (DDGS) on growth performance, small intestinal morphology, and innate immune response in broiler chickens from 1 to 21 d of age. Nine replicates of 5 birds each were assigned to dietary treatments consisting of a control diet without antibiotic (C), and diets containing 11 mg/kg of virginiamycin, 0.25% of yeast cell wall (YCW), 0.2% of a commercial product Maxi-Gen Plus, 0.025% of nucleotides, 0.05% of nucleotides, or a diet containing 10% of DDGS. On d 21, 5 birds per treatment were euthanized and approximately 5-cm long duodenum, jejunum, and ileum segments were collected for intestinal morphology measurements. Cecal tonsils and spleen were collected to measure the gene expression of toll-like receptors TLR2b, TLR4, and TLR21, macrophage mannose receptor (MMR), and cytokines IFN-γ, IL-12, IL-10, and IL-4. No significant difference was observed for growth performance parameters. However, diets containing 0.05% of nucleotides and YCW significantly increased (P < 0.05) villus height in the jejunum. Furthermore, the number of the goblet cells per unit area in the ileum was increased (P < 0.05) in diets supplemented with yeast-derived products. The expression of TLR2b in the spleen was down-regulated for diets supplemented with nucleotides and antibiotic. In addition, lower expression of TLR21 and MMR was observed in the spleen of birds receiving yeast-derived products and antibiotic. However, expression of TLR4 in the spleen was up-regulated in diets supplemented with YCW and nucleotides. The expression of IFN-γ and IL-12 was down-regulated in the spleen of birds fed diets supplemented with yeast-derived products. In addition, inclusion of YCW, Maxi-Gen Plus, or 0.05% of nucleotides down-regulated the expression of IL-10 and IL-4 in the cecal tonsils. In conclusion, down-regulation of receptors and cytokines in spleen and cecal tonsils of birds fed diets supplemented with yeast-derived products may suggest that yeast products do not exert immune stimulating effect under normal health conditions.

The effect of canola meal tannins on the intestinal absorption capacity of broilers using a D-xylose test.

In three D-xylose absorption experiments, the effect of 1% HCl/methanol, 70% methanol or 70% acetone extracts of canola meal (CM) or 70% acetone extract of soybean meal (SBM) containing polyphenols, phenolic acids, tannins and phytic acid on intestinal absorption capacity of broilers was determined. In Exp. 1, the experimental groups received orally D-xylose solution alone or with methanol/HCl, methanol or acetone extracts of CM. In Exp. 2, the experimental groups received D-xylose alone or with acetone extracts of CM or SBM. In Exp. 3, the experimental groups received D-xylose plus sucrose solution or D-xylose plus acetone extracts of CM or SBM. In Exps. 2 and 3, the CM extracts contained 2.7 and 2.6, 2.4 and 2.3, 3.2 and 3.2, and 2.4 and 2.2 times higher polyphenols, phenolic acids, tannins and condensed tannins than the corresponding SBM extracts respectively. Blood samples were collected in 40-min intervals, and plasma D-xylose was measured. Compared to the Control, plasma D-xylose in Exp. 1 was lower (p < 0.001) by 81, 69 and 73% at 40-min, by 41, 44 and 37% at 80-min and by 22, 31, and 23% at 120-min post-ingestion of the HCl/methanol, methanol and acetone extracts respectively. In both Exps. 2 and 3, plasma D-xylose level was lower (p < 0.001) in groups dosed with CM extract or SBM extract at each time of blood collection, when compared to the respective Control group. However, in Exp. 3, birds dosed with SBM extract had higher plasma D-xylose than CM extract-dosed birds by 28, 8 and 21% at 40, 80 and 120 min respectively (p < 0.01). In conclusion, although CM extract caused a lower absorption of D-xylose, based on 5 to 10% of CM inclusion levels in practical broiler rations, the soluble bioactive components of CM will likely have minor impact on the absorption capacity of the chicken intestine.

The effect of phytase and fructooligosaccharide supplementation on growth performance, bone quality, and phosphorus utilization in broiler chickens.

An experiment was conducted to investigate the effects of phytase and 2 levels of fructooligosaccharide (FOS) supplementation on growth performance, bone mineralization, and P utilization of broiler chickens. A total of 210 day-old male broiler chickens (Ross) were randomly placed into 7 dietary treatments consisting of 6 replicates with 5 birds per pen. The experiment was designed as an augmented 2 × 3 factorial arrangement with 0 or 500 U/kg of phytase and 0, 0.5% or 1% of FOS added to a reduced Ca (0.8%) and available P (0.25%) negative control diet (NC). A positive control diet (PC) that contained 1% Ca and 0.45% available P was also included. During the entire experimental period, phytase supplementation significantly improved (P < 0.05) the feed conversion ratio (FCR), BW gain (BWG), and feed intake. Birds fed the PC diet showed significantly higher bone mineral density (BMD) and bone mineral content (BMC) in both femur and tibia bones (P < 0.0001) than those fed the NC diet. Phytase supplementation increased femur BMD (P < 0.05), whereas FOS decreased femur BMD and BMC (P < 0.05). Phosphorus utilization was significantly higher for the NC diet (P < 0.0001). Phytase alone and in combination with 0.5% FOS increased P utilization significantly when compared with other treatments (P < 0.05). Fructooligosaccharides, especially at the level of 0.5%, increased P retention. In conclusion, phytase supplementation in low Ca and P diets improved growth performance, bone quality, and P utilization. However, supplementing NC diets with phytase and FOS did not result in bone mineralization values comparable with that of the PC diet. The application of dietary FOS alone had a negative effect on broiler bone quality.

The effect of protease, amylase, and nonstarch polysaccharide-degrading enzyme supplementation on nutrient utilization and growth performance of broiler chickens fed corn-soybean meal-based diets.

A study was conducted to determine if amylase and protease addition would improve nutrient digestion during the first 2 wk of growth. The experimental treatments included a control corn-soybean meal-based diet and diets supplemented with either amylase or amylase plus protease. No effect of enzyme supplementation was observed on BW gain and feed conversion ratio. This was corroborated by similar ileal starch and protein digestibility values, which averaged 96.8, 96.8, and 96.9% and 83.9, 80.1, and 79.6%, respectively, for the control and for the amylase or amylase plus protease supplemented diets. Total tract digestibility of starch averaged 97.8, 97.7 and 97.7% for the 3 diets and was followed by a similar diet with AMEn values of 3,129, 3,129, and 3,106 kcal/kg. In another study, a 2(3) factorial arrangement of 8 dietary treatments was used to evaluate the effect of corn particle size (conventional or coarse vs. fine) and the addition of a nonstarch polysaccharide enzyme, amylase, or both on growth performance and nutrient utilization of broiler chickens from 1 to 21 d of age. Chickens fed a diet containing a conventionally ground corn (geometric mean diameter of 736 µm) showed higher (P < 0.001) BW gain (808 vs. 750 g/bird) and lower feed conversion ratio (1.27 vs. 1.32) than those consuming a fine corn-containing diet (geometric mean diameter of 482 µm). This was further substantiated by a lower AMEn content (2,852 vs. 2,972 kcal/kg). Addition of amylase had no effect on growth performance of chickens fed a conventional corn-containing diet, but improved BW gain, feed conversion ratio, and diet AMEn in those fed the finely ground corn, possibly due to increased starch digestion in the upper gut. Addition of nonstarch polysaccharide enzymes was effective for both diets, with the most pronounced effects observed in feed conversion ratio for the conventional corn-containing diet (1.27 vs. 1.23) and BW gain (750 vs. 789 g/bird) for the fine corn-containing diet. This was followed by the same magnitude of difference in diet AMEn content, which increased from 2,972 to 3,042 and 2,852 to 3,009 kcal/kg following enzyme addition.