The development of feedstuff retainable phosphorus values for broilers.

Presently, phosphorus requirements are based on consumption of nonphytate phosphorus (NPP), which does not account for the fact that NPP may not be completely available and that phytate phosphorus can be partially utilized to fulfill phosphorus requirements. Phosphorus retention values for feed ingredients, accounting for NPP and phytate phosphorus, and total retainable phosphorus requirements are needed to formulate diets that meet the phosphorus requirements of poultry but that do not result in excessive amounts of phosphorus in poultry excreta. A bioassay was conducted to determine retention of phosphorus from calcium phosphates. Eight levels of a reagent-grade monocalcium phosphate, monohydrate, (MCP) were added to a cornsoy, semi-synthetic basal diet containing an acid-insoluble ash marker and offered to individually caged 10-d-old male broilers. After acclimation to the diets for 3 d, excreta were collected for 48 h. Diet and excreta samples were analyzed for total phosphorus, phytate phosphorus, and acid insoluble ash. Retentions of the basal total, NPP, and phytate phosphorus were determined to be 43.2, 65.5, and 32.3%, respectively. Retention of the phosphorus from different phosphorus sources was determined to be dependent on the amount of source included in the diet. The maximum retentions of total phosphorus, NPP, and phosphorus from MCP for the basal-MCP test diets were 67.6, 80.2, and 98%, respectively. The maximum retention of dietary retainable phosphorus occurred with a 2:1 ratio of 0.48% calcium and 0.24% retainable phosphorus. The retainable phosphorus intakes for 10-to-15-d-old broilers required to provide a steady physiological state was 108 mg/d, as determined by two-line regression analysis. Retainable phosphorus requirements based on segmented line regression analysis using bone strength measurements for 0-to-3-wk-old chicks and 3-to-6-wk-old broilers were 0.39 and 0.30%, respectively.

Hydrogen gas production of broiler chicks in response to soybean meal and alpha-galactoside free, ethanol-extracted soybean meal.

In order to measure broiler chick hydrogen gas production, a sealed atmosphere chamber was constructed and chicks were intubated with soybean meal (SBM), alpha-galactoside free, ethanol-extracted soybean meal (ESBM), and ESBM with alpha-galactosides added to the levels of SBM (ESBMG). Six male broiler chicks averaging 156 g of weight were deprived of feed for 12 h prior to intubation with 6 g of the test soybean meals. Two chicks were used for each treatment. Following intubation, chicks were placed in the sealed atmosphere chamber for 20 min at 2-h intervals for 28 h. At the end of this 20-min period, a sample of the chamber atmosphere was collected with a gas-tight syringe and analyzed for hydrogen gas by gas-solid chromatography. The hydrogen production of the two chicks intubated with SBM peaked 7 h postintubation at 127 ppm. The ESBM produced a peak at approximately 17 h postintubation at 26 ppm. Intubation with ESBMG resulted in peak hydrogen production at approximately 12 h postintubation at an average of 67 ppm. Results indicate that chicks intubated with SBM produced 3.2 times the amount of total hydrogen gas than those chicks intubated with ESBM. Chicks intubated with ESBMG produced 2.2 times the amount of total hydrogen gas than chicks intubated with ESBM. The research indicates the alpha-galactoside oligosaccharides are a major cause of hydrogen gas production from SBM in poultry.

A bioassay to determine the effect of phytase on phytate phosphorus hydrolysis and total phosphorus retention of feed ingredients as determined with broilers and laying hens.

In order to accurately formulate diets for broilers and laying hens to meet phosphorus requirements without overfeeding, precise knowledge of an individual feed ingredient's contribution to the retainable phosphorus is needed. Seven feed ingredients, included as the sole source of phosphorus, were tested with and without the addition of 600 phytase units (FTU) phytase/kg diet, in a 5-d bioassay with 10 22-d-old male broilers. Without addition of phytase, the amounts of phytate phosphorus hydrolyzed in corn, soybean meal, wheat, wheat midds, barley, defatted rice bran, and canola were 30.8, 34.9, 30.7, 29.1, 32.2, 33.2, and 36.7%, respectively. The addition of phytase increased (P < or = 0.05) each value to 59.0, 72.4, 46.8, 52.2, 71.3, 48.0, and 55.8%, respectively. The addition of phytase increased total phosphorus retention from 34.8, 27.0, 16.0, 31.9, 40.3, 15.5, and 39.4% to 40.9, 58.0, 33.8, 43.4, 55.5, 26.5, and 45.7%, respectively. A similar bioassay was conducted with laying hens fed corn, soybean meal, and defatted rice bran. Without phytase addition, phytate phosphorus hydrolyzed in soybean meal, corn, and rice bran was determined to be 25.7, 23.0, and 36.1%, respectively, and was increased (P < or = 0.05) to 62.4, 52.0, and 50.9%, respectively, with the addition of 300 FTU phytase/kg feed. Total phosphorus retention of soybean meal, corn, and rice bran increased from 36.8, 28.6, and 35.9% to 53.4, 44.7, and 43.0%, respectively, with the addition of phytase.

Nutrient content and protein and energy digestibilities of ethanol-extracted, low alpha-galactoside soybean meal as compared to intact soybean meal.

A study was conducted with adult Leghorn roosters to determine TMEn, dry matter digestibility, amino acid content and digestibility, and cellulose and hemicellulose content and digestibility of ethanol-extracted, low alpha-galactoside soybean meal (SBM). Results were compared to that of commercially available 47% CP SBM. Twenty-one roosters were utilized; seven roosters were precision-fed each of the two soybean meal treatments, and seven served as feed-deprived controls. Excreta were collected for 48 h after feeding. A second experiment compared the TMEn, as determined with roosters, to AMEn, as determined with male broiler chicks, of 44% and 47% CP SBM and three different ethanol extraction procedures to remove alpha-galactosides. The ethanol extraction procedure concentrated CP, gross energy, and TMEn. Dry matter digestibility of SBM increased from 52.1% (control SBM) to 63.3% (ethanol-extracted SBM) because of the ethanol extraction procedure. The average amino acid digestibility of ethanol-extracted SBM was 91.6%, compared to 88.0% for control SBM. The digestibility of methionine, alanine, valine, and lysine was improved by the ethanol extraction procedure. Total cellulose and hemicellulose digestion, measured as digestion of specific monosaccharide components, was increased by the ethanol extraction. The TMEn and AMEn values for the different control and extracted SBM were similar. These data indicate that the ethanol extraction of SBM to remove alpha-galactosides resulted in a product that is more protein and energy dense than commercial SBM. Advantages in digestion of amino acids and fiber may contribute to the increase in TMEn observed in both young and adult birds.

Effect of oligosaccharide additions on nitrogen-corrected true metabolizable energy of soy protein concentrate.

In order to determine TMEn response to individual saccharide moieties, five different sugar additions were made to a soy protein concentrate control that contained low levels of oligosaccharides. The sugar additions to the control were made to approximate the amounts of raffinose, stachyose, and sucrose found in soybean meal (SBM). All samples were precision-fed to adult Leghorn roosters to determine TMEn values. The control had a dry matter gross energy (GE) of 4,873 kcal/kg, CP of 73.1%, and TMEn value of 3,757 kcal/kg. Raffinose and stachyose significantly reduced TMEn values for the control. Sucrose did not exhibit this effect. In a second experiment, different levels of stachyose and raffinose were added separately to the control to develop a TMEn dose response curve for these alpha-galactosides of SBM. The TMEn of soy protein concentrate was found to be significantly decreased by stachyose and raffinose inclusion and to be dose dependent.

Two distinct yolk lipoprotein complexes from Caenorhabditis elegans.

The four yolk polypeptides of the nematode Caenorhabditis elegans are found in two types of lipoprotein particle: 12 S particles with Mr estimated at 450,000 and 8 S particles with Mr estimated at 250,000. Both types of particle contain approximately 8% phospholipids, 3% triglycerides, and 3% other lipids by mass. All four C. elegans yolk polypeptides can be found in either 12 or 8 S particles, depending upon the conditions of isolation. While the properties of the 12 and 8 S lipoprotein particles are consistent with a dimermonomer relationship, the asymmetric distribution of the yolk polypeptides between 12 and 8 S fractions suggests that at least two different oligomeric lipoprotein complexes are present in C. elegans embryos. In order to clarify the subunit composition of the C. elegans yolk lipoproteins, the patterns of polypeptides retained in immunoaffinity binding procedures by immunoglobulins of different antigenic specificities have been compared. When immunoaffinity binding is performed in the absence of sodium dodecyl sulfate, three C. elegans yolk proteins (yp170A, yp115, and yp88) are retained together by polyclonal immunoglobulins directed against either yp115 or yp88. A monoclonal immunoglobulin also retains these three proteins together. In contrast, a second monoclonal immunoglobulin retains only the fourth yolk protein (yp170B). Aggregate species, evidently reflecting the spontaneous formation of interchain disulfide bonds, indicate that yp170A and yp88 are physically associated, whereas yp170B self-associates in dimers. It is concluded that there are two distinct lipoprotein complexes in C. elegans: the A complex, which consists of yp170A, yp115, and yp88 and is essentially heterodimeric and the B dimer, a simple dimer of yp170B.

Effect of oligosaccharide-free soybean meal on true metabolizable energy and fiber digestion in adult roosters.

Adult Leghorn roosters were precision-fed 44% protein soybean meal (SBM) or 80% ethanol-extracted soybean meal (ESBM) to determine nutritional differences due to the removal of oligosaccharides. Dry-matter digestibility and TMEn as well as apparent hemicellulose and cellulose digestion were determined. The transit time, rate of passage, and pH of the cecal contents were also established with roosters that had consumed a .3% chromic-oxide diet that contained SBM or ESBM. The protein content of the SBM and the ESBM was 46.1 and 64.4%, respectively. The true-dry matter digestibility of SBM was 54%. The TMEn of the SBM on a dry-matter basis was 2,794 kcal per kg; and the apparent hemicellulose and cellulose digestibility was 9% and 0%, respectively. The true dry-matter digestibility of the ESBM was 67%. On a dry-matter basis, the TMEn of the ESBM was 3,368 kcal per kg; and the apparent hemicellulose and cellulose digestibility was 62% and 35%, respectively. Oligosaccharide digestion occurred mainly anterior to the ileo-cecal junction. Hemicellulose and cellulose digestion occurred predominantly in the lower gastrointestinal tract. The transit time for the ESBM diet was 115 min, compared to 71 min for the SBM diet. Based on a 16-h collection of excreta, the rate of passage was approximately 50% slower for the ESBM diet than for the SBM diet. The pH of the cecal contents from roosters consuming the ESBM diet was 7.21 versus 6.51 for the SBM diet.