Organic trace mineral levels in the first 96-h post-hatch impact growth performance and intestinal gene expression in broiler chicks.

Alterations in nutrient intake in the avian neonatal posthatch period can impact development, performance, and metabolism in adulthood. Very little is known about how mineral levels during the post-hatch period affect or "program" gene expression patterns later in life. The objective of this study was to determine the effect of post-hatch (0 to 96 h) dietary mineral supplementation on performance, tissue mineral content, and intestinal gene expression profiles in 21-day-old broiler chicks. One-day-old chicks were randomly assigned to one of two treatment groups consisting of N (organic Zn, Cu, and Mn provided at 100 % of recommendations (National Research Council 1994)) and/or L (organic Zn, Cu, and Mn provided at 20 % of recommendations (National Research Council 1994)) diets fed in two intervals (days 1­4, days 5­21) as follows: (1)N­Lor (2)L­L. Performance parameters did not differ between treatments except that body weight gain was greater (P < 0.05) in L­L birds than N­L birds over the experimental period. Bone mineral content was similar for both treatments at day 21. Intestinal gene expression profiling was examined using the Affymetrix GeneChip Chicken genome array. Ingenuity pathway analysis revealed differences in gene expression profiles between N and L treatments at day 5. At day 21, profiles were unique between N­L and L­L, suggesting that the diet fed until day 4 had an impact on gene expression patterns at day 21 even when birds were fed the same diets day 5­day 21. In this study, we demonstrated that diets fed for the 96 h post-hatch had long-term effects on gene expression, providing unique information as to why post-hatch diets are so important for the longterm bird health and productivity.

Effects of yeast cell wall-derived mannan-oligosaccharides on jejunal gene expression in young broiler chickens.

The use of mannan-oligosaccharides (MOS) as alternatives to antibiotic growth promoters (AGP) has gained in popularity in recent years due to regulatory restrictions of using AGP in food animal production. Benefits of MOS usage include improvement on animal performance, feed efficiency, and gastrointestinal health. The molecular mechanisms of these functions however are not clear. The goal of the current study was to use a transcriptomics approach to investigate the effects of MOS on the intestinal gene expression profile of young broilers and characterize biological gene pathways responsible for the actions of MOS. One hundred and twenty 1-d-old Cobb 500 broiler chicks were randomly divided into 2 groups and were fed either a standard wheat-soybean meal-based (control) diet or the same diet supplemented with 2.2 g/kg of MOS (Bio-Mos, Alltech, Nicholasville, KY) for 3 wk, followed by jejunal gene expression profiling analysis using chicken-specific Affymetrix microarrays. Results indicated that a total of 672 genes were differentially expressed (P < 0.01 and fold change >1.2) in the jejunum by MOS supplementation. Association analysis indicated that differentially expressed genes are involved in diverse biological functions including energy production, cell death, and protein translation. Expression of 77 protein synthesis-related genes was differentially regulated by MOS in the jejunum. Further pathway analysis indicated that 15 genes related to oxidative phosphorylation were upregulated in the jejunum, and expression of genes important in cellular stress response, such as peroxiredoxin 1, superoxide dismutase 1, and thioredoxin, were also increased by MOS. Differential expression of genes associated with cellular immune processes, including lysozyme, lumican, ß 2-microglobin, apolipoprotein A-1, and fibronectin 1, were also observed in MOS-fed broilers. In summary, this study systematically identified biological functions and gene pathways that are important in mediating the biological effects of MOS in broilers.

Effects of feeding different concentration and forms of zinc on the performance and tissue mineral status of broiler chicks.

1. Two studies were conducted to investigate the effect of feeding different concentration and forms of zinc (Zn) on the performance and tibia Zn status of broiler chicks. 2. In Experiment 1, chicks fed on the control or the diet supplemented with 12?mg of Zn as sulphate had lower feed intake, weight gain and tibia Zn content than other treatment groups. Chicks given 12 and 24 mg of organic Zn in starter and grower phases, respectively, had the same performance and tibia Zn content as those fed 40 mg of Zn as sulphate and the same performance but higher tibia Zn content than those given 12 mg of Zn as organic over the 42 d. 3. In Experiment 2, chicks given 24 mg organic Zn had greater weight gain than chicks fed on the other treatment diets in the starter period. Chicks fed on the control diet had lower tibia Zn content than chicks fed other treatment diets. Chicks given 80 mg Zn as sulphate had higher tibia Zn content than chicks fed the other treatment diets except those given 40 mg of Zn as sulphate. 4. The results from these trials indicate that feeding lower concentration of Zn as organic form may better promote the growth performance of broiler chicks.

Effects of organic and inorganic dietary selenium supplementation on gene expression profiles in oviduct tissue from broiler-breeder hens.

Selenium (Se) is an essential component of at least 25 selenoproteins involved in a multitude of physiological functions, including reproduction. However, relatively little is known about the mechanisms by which Se exerts its physiological effects in reproductive tissue. The objective of this study was to compare the effect of long-term inorganic Se (sodium selenite, SS) and organic yeast-derived Se (Sel-Plex(®), SP) supplementations on tissue Se content and gene expression patterns in the oviduct of broiler-breeder hens. Hens were randomly assigned at 6 weeks of age to one of the three treatments: basal semi-purified diet (control), basal diet+0.3 ppm Se as SP or basal diet+0.3 ppm Se as SS. At 49 weeks, oviduct tissue from hens randomly selected from each treatment (n=7) was analyzed for Se content and gene expression profiles using the Affymetrix Chicken genome array. Gene expression data were evaluated using GeneSpring GX 10.0 (Silicon Genetics, Redwood, CA) and Ingenuity Pathways Analysis software (Ingenuity Systems, Redwood City, CA). Oviduct Se concentration was greater with Se supplementation compared with the control (P≤0.05) but did not differ between SS- and SP-supplemented groups. Gene expression analysis revealed that the quantity of gene transcripts associated with energy production and protein translation were greater in the oviduct with SP but not SS supplementation. Targets up-regulated by SP, but not SS, included genes encoding several subunits of the mitochondrial respiratory complexes, ubiquinone production and ribosomal subunits. SS hens showed a decrease in transcripts of genes involved in respiratory complexes, ATP synthesis and protein translation and metabolism in oviduct relative to control hens. In this study, although tissue Se concentrations did not differ between hens fed SS- and SP-supplemented diets, expression patterns of genes involved in energy production and protein synthesis pathways differed between treatments. These variations may partially explain the differences in reproductive performance reported in hens fed different forms of Se.

Effects of feeding different forms of zinc and copper on the performance and tissue mineral content of chicks.

A study was conducted to investigate the effects of feeding inorganic or organic Zn and Cu on the performance and tissue mineral content of chicks. A corn-soybean meal diet without Cu and Zn supplementation, containing 31 mg of Zn/kg of diet and 6.6 mg of Cu/kg of diet, was used as a basal diet. Organic Zn (a chelated Zn proteinate) and organic Cu (a chelated Cu proteinate) were used as organic sources for comparison with inorganic reagent-grade sulfates. Supplements provided 20 mg/kg of Zn and 8 mg/kg of Cu. A 3x3 factorial arrangement of treatments consisting of feeding the basal diet with 3 supplements (none, sulfate, or organic) of Cu and of Zn was used. Ten groups of 6 one-day-old male broilers were assigned to each of 9 dietary treatments. Tap water and feed were supplied on an ad libitum basis during the 3-wk trial. The Zn and Cu content in the mucosa of the duodenum of the chick was determined. Dietary supplementation of Zn increased (P<0.01) weight gain, feed intake, and G:F of chicks. The G:F for chicks fed both inorganic sources of Zn and Cu was lower (P<0.01) than that for chicks fed only the inorganic source of Zn. Dietary inclusion of Zn increased (P<0.01) tibia and plasma Zn content. The tibia Zn content for chicks fed organic Zn was higher (P<0.01) than that for chicks fed inorganic Zn. Liver Cu content was decreased (P<0.05) by dietary inclusion of Zn. The Zn and Cu contents in the mucosa of chicks fed the organic source were higher (P<0.01) than those of chicks fed the control diet. The feed conversion data suggest that the antagonism between Zn and Cu occurred when the inorganic forms, but not organic forms, of these 2 minerals were included in a chick diet.

Effect of enzyme supplementation and acidification of diets on nutrient digestibility and growth performance of broiler chicks.

Two experiments were conducted to examine the effects of alpha-galactosidase supplementation and acidification of diets on nutrient digestibility and growth performance of broiler chicks. In experiment 1, dietary treatments consisted of feeding a low-energy basal diet (2.74 Mcal of ME/kg) alone, the basal diet supplemented with 1,724 units of alpha-galactosidase per kg, the basal diet supplemented with 2% citric acid, or the basal diet supplemented with both. alpha-Galactosidase significantly increased feed intake, weight gain, AME(n) of the diets, and retention of CP and neutral detergent fiber (NDF) (P < 0.05). Citric acid significantly increased the retention of DM, CP, and NDF, but decreased feed intake and weight gain. The greatest values for DM and NDF retention and for AME(n) were obtained with the combination of alpha-galactosidase plus citric acid. In experiment 2, chicks were fed diets with 2 levels of energy (2.74 or 3.11 Mcal/kg), 2 levels of citric acid (0 or 1.5%), and 2 levels of alpha-galactosidase (0 or 1,724 units/kg) in a 2 x 2 x 2 factorial arrangement of treatments. alpha-Galactosidase significantly increased the reducing sugar concentration in the crop content, whereas citric acid decreased the pH and increased the reducing sugar concentration in the crop content. Citric acid decreased the gain to feed ratio in the absence but not in the presence of alpha-galactosidase. The data from these studies indicate that acidification of diet improves the efficacy of alpha-galactosidase.

Effects of organic zinc and phytase supplementation in a maize-soybean meal diet on the performance and tissue zinc content of broiler chicks.

1. The purpose of this study was to investigate the effects of Bioplex Zn (a chelated zinc proteinate) and phytase supplementation in a maize-soybean meal diet on the performance and tissue zinc (Zn) content of broiler chicks. Treatment structure consisted of a 2 x 6 factorial arrangement with two inclusions of phytase (0 or 500 PU/kg) and 6 of Bioplex Zn providing 0, 2, 4, 8, 16 and 32 mg Zn/kg diet. A total of 864 chicks were randomly assigned to each of 12 dietary treatments with 6 replicate cages of 12 chicks. 2. Dietary inclusion of phytase increased feed intake, weight gain, plasma Zn content, tibia Zn content, tibia and ash weight. 3. Dietary supplementation of Bioplex Zn linearly increased feed intake, weight gain, gain to feed ratio, plasma Zn concentration, liver Zn concentration, tibia Zn content, tibia and ash weight. 4. An interactive effect of phytase and Bioplex Zn on feed intake, weight gain, tibia Zn concentration and tibia ash weight was found. 5. One slope, straight broken-line analysis of weight gain regressed on the supplemental Zn level provided as Bioplex Zn indicated that 12 mg/kg supplemental Zn without phytase and 7.4 mg/kg supplemental Zn with phytase were required for the optimal weight gain of chicks.

The effect of dietary selenium source and level on the uptake of selenium by developing chick embryos.

We studied the effect of dietary source (organic or inorganic) and level of Se on the Se uptake of chick embryos. After receiving a low-Se diet for 16 wk, 126 Leghorn laying hens were randomly assigned to one of seven dietary treatments. Treatments consisted of feeding a low-Se basal diet alone or with one of three levels of added Se (0.1,0.2, or 0.3 mg/kg Se) supplied by sodium selenite or Se-enriched yeast. Fertile eggs were collected after 33 d of feeding the experimental diets. Eggs were subjected to no incubation or incubation for 5, 10, 15, or 20 d. Non-incubated eggs were separated, and the yolk and albumen were assayed separately for Se. Incubated eggs were separated into the embryo and extra-embryonic portions, which were assayed separately for Se. Se concentrations of the yolk and albumen were significantly different among dietary treatments. Compared with eggs from hens fed sodium selenite, yolk and albumen Se concentrations were higher in eggs from hens fed Se yeast. Embryonic and extra-embryonic Se concentrations were higher in eggs from hens fed Se yeast than eggs from hens fed sodium selenite. The largest increase in embryonic Se concentration was observed during Days 10 to 15 of incubation. It was concluded that Se source and dietary inclusion level influenced the Se concentration of portions of developing embryonated eggs and that embryonic Se concentration changed during incubation.

The effect of dietary crude protein on growth, ammonia concentration, and litter composition in broilers.

An experiment was conducted to determine the effect of diets with reduced CP and supplemental amino acids on broiler performance, N excretion, litter characteristics, and equilibrium NH3 gas concentration. Results suggest that reducing CP (and lysine) below 241 g/kg (13.7 g/kg lysine) in the diets fed during the first 3 wk may slightly increase feed:gain and therefore may not be advisable. During the period 22 to 43 d of age there were no significant differences in weight gain and BW at 6 wk of age when reducing CP from 215 g/kg (11.5 g/kg lysine) to 196 g/kg (11.3 g/kg lysine), but feed intake and feed:gain ratio increased. However, reducing CP did cause equilibrium NH3 gas concentration and litter N to decline by 31 and 16.5%, respectively. Both of these advantages will improve air quality within the housing facility and possibly reduce heating costs during winter associated with higher ventilation rates required to reduce elevated NH3 gas concentrations.

The effect of dietary protein and phosphorus on ammonia concentration and litter composition in broilers.

An experiment was conducted to determine whether broiler litter concentration of N and P and equilibrium NH3 gas concentration can be reduced by reducing dietary CP and P levels and supplementing with amino acids and phytase, respectively, without adversely affecting bird performance. Equilibrium NH3 gas concentration above the litter was measured. The experiment was divided into a starter period (1 to 21 d) and grower period (22 to 42 d), each having two different CP and P levels in a 2 x 2 factorial arrangement. The CP treatments consisted of a control with a mean CP of 204 and 202 g/kg for starter and grower periods, respectively, and a low CP diet with means of 188 and 183 g/kg, respectively, but with similar amino acid levels as the control. The P treatments comprised starter and grower control diets containing means of 6.7 and 6.3 g/kg P, respectively, and low P treatment means of 5.8 and 5.4 g/kg P supplemented with 1.0 g/kg phytase. Reducing starter diet CP by 16 g/kg reduced weight gain by 3.5% and, hence, body weight at 21 d of age, but did not affect feed intake or feed efficiency. Reducing P did not affect feed intake and weight gain, but improved feed efficiency by 2.0%. Responses in feed intake and efficiency to CP depended on the level of dietary P. For the grower period there were no significant differences in feed intake, weight gain, and feed efficiency, nor in body weight at 42 d of age, after correcting for 21-d body weight, between CP and P treatments. There were significant (P < 0.001) reductions in litter N and P concentrations, but not equilibrium NH3 gas concentration, moisture content, or pH, for low CP and P diets. Mean equilibrium NH3 gas concentration was 63 ppm. Litter N concentration was reduced 16.3% with the low CP diets, and litter P by 23.2% in low P treatments. The results suggest that dietary manipulation shows merit for reducing litter N and P concentrations while maintaining acceptable production performance from broilers.

Pearl millet in layer diets enhances egg yolk n-3 fatty acids.

A study was conducted to determine whether substitution of pearl millet for corn in layer diets could enrich egg yolks with n-3 fatty acids. Seventy-two Single Comb White Leghorn hens of a commercial strain in their second cycle of production were fed isocaloric, isonitrogeneous diets (2,860 kcal AMEn/kg and 16% CP) formulated with corn, equal amounts of corn and pearl millet, or pearl millet as the grain source. Each of the three diets was fed to eight replicate groups of three hens for 6 wk. Dietary treatments had no effect on feed intake, BW, egg production, egg weight, and yolk weight. Feeding millet in place of corn significantly decreased yolk pigmentation. The ratio of n-6 fatty acids to n-3 fatty acids in eggs was 13.1, 10.1, and 8.3 for hens fed corn, corn+pearl millet, and pearl millet, respectively. Feeding pearl millet produces eggs significantly (P < 0.05) enriched in n-3 fatty acids.

Effect of dietary protein and energy levels on pullet development.

The effects of protein and energy levels in rearing diets and protein levels in layer diets on pullet development and subsequent layer performance were studied using 576 Single Comb White Leghorn pullets of a commercial strain. Twelve groups of 16 1-d-old chicks were assigned to each of three dietary treatments. All chicks were fed a 19% CP starter diet during Week 1. Respective protein levels in diets fed during Weeks 2 through 6, 7 through 14, and 15 through 18 were 13.5, 15.8, and 18.9% for the increasing protein treatment; 15.8, 15.8, and 15.8% for the constant protein treatment; and 18.9, 15.8, and 13.5% for the decreasing protein treatment. During Weeks 15 through 18, half of the groups in each protein treatment were assigned to a high (3.09 Mcal AMEn/kg) or a low (2.78 Mcal AMEn/kg) energy diet. After 18 wk, half of the pullets within each rearing treatment were fed a layer diet containing 16% CP and 0.34% methionine, whereas the other half were fed a layer diet with 19% CP and 0.40% methionine. Increasing the level of protein fed during Weeks 2 through 6 significantly (P < 0.05) increased body weight and feed intake up to 14 wk of age. High dietary energy increased weight gain and decreased feed intake during Weeks 15 through 18. Mortality and days to 50% egg production, as well as egg production, feed intake, feed conversion, and egg weight during the first 16 wk following photostimulation were not affected by rearing dietary treatments. Egg weight, but not other production parameters, was significantly increased by raising CP in the layer diet from 16 to 19%.

The effect of dietary phytase on growth performance and phosphorus utilization of broiler chicks.

Two experiments were conducted to evaluate the effect of dietary phytase and increasing levels of available phosphorus (P(av)) on the growth performance and phosphorus metabolism of broiler chicks. In both experiments, graded levels of P provided by dicalcium phosphate and of phytase were added to a low-P corn-soybean meal basal diet. In Experiment 1, diets providing .21, .29, .37, and .44% P(av) without phytase; .21% P(av) plus .05, .10, or .30% phytase; and .29% P(av) plus .10% phytase were each fed to four groups of seven chicks, 3 days of age. In Experiment 2, diets providing P(av) levels of .32, .38, and .44% and phytase levels of .5, 1.0, and 1.5% (250, 500, and 750 units/kg) in a factorial arrangement were each fed to four groups of eight chicks, 5 days of age. In Experiment 1, increasing dietary P(av), but not phytase, increased feed intake, weight gain, feed conversion, plasma inorganic P, tibia and toe ash, and tibia breaking strength (P < or = .05). Plasma inorganic P responded quadratically to increasing dietary phytase. In Experiment 2, feed intake and weight gain were increased by elevating the level of P(av), but not by phytase. Toe and tibia ash and plasma inorganic P were increased by dietary phytase and increasing levels of P(av) (P < or = .01). Tibia breaking strength was improved (P < or = .05) by dietary phytase but not by increasing levels of P(av). The P excretion was elevated (P < or = .01) by increasing levels of P(av) and was decreased by supplemental phytase (P < or = .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Variations in muscle chemical composition, pH, and protein extractability among eight different broiler crosses.

Variations in muscle chemical composition, pH, and protein extractability were studied using male broilers of eight different genetic crosses of commercial strains. Three replicate groups of 24 birds of each cross were grown in floor pens using commercial corn-soybean meal diets. At 8 wk of age, three birds per replicate, weighing within 5% of the pen average, were slaughtered, scalded, defeathered, eviscerated, and chilled in ice slurries overnight. Muscles were excised from breasts and thighs, and trimmed of skin and external fat. Proximate analysis was conducted using ground muscle pooled within replicate groups. Breast muscle of all strain crosses contained more (P < or = .05) total protein (ranging from 20.7 to 23.6%) and moisture (74.6 to 75.9%), and less fat (1.0 to 2.0%) than thigh muscle, which contained 18.1 to 21.3% protein, 72.8 to 73.8% moisture, and 5.0 to 7.2% fat. The pH of breast muscle was lower (P < or = .05) than that of thigh muscle for four of the eight strains, and protein extractability of breast muscle was greater (P < or = .05) than that of thigh muscle for all strains. There were significant differences among strains in chemical composition, pH, and protein extractability for both breast and thigh muscles. The correlation between percentage protein and fat was positive in breast (r = .72, P < .05) and negative in thigh muscle (r = -.77, P < .05). However, no significant correlations were observed between the chemical constituents of breast muscle with the respective constituents of thigh muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of dietary aluminum and vitamin D interaction on growth and calcium and phosphorus metabolism of broiler chicks.

The interaction of dietary aluminum (as aluminum sulfate) and vitamin D on growth performance and calcium and phosphorus metabolism was investigated using male broiler chicks. A corn-soybean broiler starter diet, containing .88% Ca and .45% available P and without added cholecalciferol (vitamin D3), was fed with 0 or .2% Al and with 0, 100, or 200 ICU of vitamin D3/kg of diet in a complete factorial arrangement. Four replicate cages of 10 chicks, 1 day of age, were assigned to each dietary treatment. Average body weight gain (328 versus 545 g), feed intake (611 versus 784 g), gain:feed (.54 versus .68), and plasma inorganic P (4.2 versus 6.7 mg/dL) were significantly reduced (P < .05) in chicks fed diets with .2% Al, compared with those fed 0% Al. These four variables were improved by increasing the level of vitamin D3 in the diet from 0 to 100 ICU/kg. However, further improvements were not obtained by elevating the vitamin D3 level to 200 ICU/kg. There were significant interactions of Al and vitamin D3 on gain, feed intake, and gain:feed, but not on plasma P. Gain and feed intake were significantly decreased by Al at each level of vitamin D3. Plasma total Ca was significantly increased by vitamin D3, but was unaffected by Al. Increasing the level of dietary vitamin D3 did not completely alleviate the negative effects of Al.

Metabolism of narasin in chickens and Japanese quail.

Thirty mature chicken hens and 60 mature Japanese quail hens were used to compare pathways of narasin excretion. Carbon-14-labeled narasin was injected into chickens (.7 microCi) and quail (.113 microCi) via cardiac puncture. Blood, sampled at varying times thereafter, and eggs and excreta collected daily for 28 days, were analyzed for 14C. Groups of six chickens and 12 quail were killed prior to [14C]narasin injection and on Days 1, 7, 14, and 28 postinjection to obtain tissue samples for 14C analysis. Blood rapidly cleared the label in both species. Less than 1% of the dose of [14C]narasin remained in blood plasma after 3 h postinjection in both chickens and quail. Label excretion peaked on Day 1 in both species, and most of the 14C was cleared via the excreta (76.7 and 93.6% of the dose for quail and chickens, respectively). Label appeared in the excreta more rapidly and cleared more quickly in quail than in chickens. After 24 h, 68 and 49% of the dose of [14C]narasin appeared in the excreta of quail and chickens, respectively. More label was recovered in the eggs of quail (4.18% of the dose) than in the eggs of chickens (1.32% of the dose). Liver, heart, fat, and ovarian tissues contained traces of radioactivity 1 day postinjection in both species. Muscle and kidney did not contain detectable amounts of label. By Day 7, all tissue had cleared 14C beyond detectable limits. The results indicate that chickens and quail metabolize [14C]narasin via similar pathways and that excretion in quail may be more rapid than in chickens.

Relationship of dietary aluminum, phosphorus, and calcium to phosphorus and calcium metabolism and growth performance of broiler chicks.

Dietary treatments providing three levels of added Al (0, .196, or .392%) as aluminum sulfate and of available phosphorus (Pav) .45, .68, or .78%) in a factorial arrangement were administered to day-old chicks in Experiment 1. Plasma inorganic phosphorus (Pi) was significantly (P less than .05) elevated by increasing Pav and was decreased by Al. Body weight gain, feed intake, and the gain:feed ratio at Day 21 were significantly decreased by increased concentrations of Al, but were unaffected by the Pav concentrations. Decreases of 39 and 73% in weight gain and of 34 and 66% in feed intake resulted from feeding .196 and .392% Al, respectively. In Experiment 2, day-old chicks were fed diets supplemented with 0 or .392% Al in combination with .9% Ca plus .45% Pav, .9% Ca plus .78% Pav, 1.8% Ca plus .45% Pav, or 1.8% Ca plus .9% Pav. After 21 days, the supplemental Al resulted in: 1) significantly poorer growth performance; 2) decreased plasma Pi, total Ca, Zn, and Mg; and 3) decreased tibia weight and breaking strength. Elevating Pav improved growth performance, plasma Pi, and tibia weight and strength, and decreased plasma total Ca. Increasing dietary Ca significantly decreased plasma Pi and increased plasma total Ca without affecting other parameters. Increasing Pav alleviated the negative effect of Al on plasma Pi without correcting the negative effect of Al on growth performance.

Effect of dietary aluminum sulfate on calcium and phosphorus metabolism of broiler chicks.

The effect of dietary aluminum sulfate on Ca and P metabolism was studied using 1-day-old male broiler chicks. In Experiment 1, practical diets providing .90% Ca plus .45% available P (Pav), .90% Ca plus .78% Pav, 1.80% Ca plus .45% Pav, or 1.80% Ca plus .90% Pav were fed with 0 or .392% A1 as aluminum sulfate for 21 days. The control diet (.90% Ca plus .45% Pav) without added A1 was fed to all chicks during Days 22 to 49. In general, A1 significantly (P less than .05) decreased BW gain, feed intake, gain:feed ratio, plasma inorganic P (Pi), tibia breaking strength, tibia weight, percentage of tibia ash, and plasma Zn, measured at Day 21. Elevating Pav increased BW gain, feed intake, gain:feed ratio, tibia weight and plasma Zn, and decreased plasma total Ca in the presence of .392% A1 plus 1.80% Ca. Plasma Pi, tibia breaking strength, and percentage of tibia ash were increased by raising dietary Pav in the presence of .392% A1 with either level of Ca. Negative effects of dietary A1 on feed intake and BW persisted through Day 49. In Experiment 2, a control diet (.90% Ca, .45% Pav) was fed for ad libitum access either alone or supplemented with .2% A1 as aluminum sulfate or with an equivalent amount of sulfate provided by potassium sulfate. The control diet was also pair-fed to chicks given .2% A1. Dietary A1 significantly depressed weight gain, feed intake, gain:feed ratio, and plasma Pi.(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolism of decoquinate in chickens and Japanese quail.

Thirty mature chicken hens and 40 mature Japanese quail hens were used in an experiment to compare pathways of decoquinate (DQ) excretion. Labelled DQ was injected into chickens (.5 microCi via wing vein puncture) and quail (.25 microCi via cardiac puncture) on Day 0. Blood was sampled at 0, 1.5, 3, 6, 9, 12, 24, and 48 h postinjection. Eggs and excreta of chickens and quail were collected for 28 and 14 days, respectively, and analyzed for 14C. Six chickens and eight quail were sacrificed prior to 14C-DQ injection and also on Days 1, 7, 14, and 34 or 32 postinjection. Samples of liver, heart, kidney, bile, skin, fat, and muscle were analyzed for 14C. Blood rapidly cleared 14C in both species, and the half-time of 14C excretion via excreta was more rapid in quail (.37 day) than in chickens (.92 day). Little 14C was found in the eggs of quail (.32% of dose) and chickens (.17% of dose). Quail appeared to excrete peak amounts of detectable 14C 1 day earlier (Day 4) than chickens (Day 5). Liver contained the greatest concentration of 14C on Day 1 in both species. By the end of the experiment, less than 1% of the dose remained in liver or other organs. Results indicate that chickens and quail metabolize 14C-DQ at comparable rates and by similar pathways.

Effect of dietary aluminum on calcium and phosphorus metabolism and performance of laying hens.

The effect was studied of feeding dietary Al as aluminum sulfate on calcium and phosphorus metabolism and performance of Single Comb White Leghorn laying hens. In Trial 1, graded levels of Al (0, .05, .10, or .15%) were added to a corn-soybean meal layer diet containing 3.3% Ca and .5% available P. Each diet was fed for 28 days to six groups of six individually caged hens. Adding .15% Al to the diet significantly (P less than .05) reduced feed intake, egg production, body weight, tibia breaking strength, and plasma inorganic P. In Trial 2, graded levels of Al (0, .1, .2, or .3%) were added to the basal diet. Each diet was fed to five or six individually caged hens for 42 days. Feeding .3% Al significantly (P less than .05) decreased plasma inorganic P in samples collected immediately following oviposition after 10 and 42 days of treatment. Plasma total Ca, tibia weight, and tibia breaking strength were unaffected by dietary treatments. Egg production and feed intake during Days 1 through 21, but not during Days 22 through 42, were significantly reduced by .3% Al. The results indicated that the addition of .3% Al to a laying hen diet has a negative effect on P metabolism and egg production.