Ratio of digestive enzymes in the chick pancreas.

The ratio of exocrine enzymes was determined in extracts from pancreata of broiler chickens. The proteins were separated by ion-exchange chromatography to determine the elution pattern and the relative concentration of the various enzymes. Amylase was about 28.9%, the three chymotrypsinogens about 20%, and a single, anionic form of trypsinogen about 10% of the total protein. Procarboxypeptidases A and B, proelastase, lipase, and a secretory trypsin inhibitor were also present.

Isolation, purification, and the amino acid sequence of a secretory trypsin inhibitor from the chicken pancreas.

A trypsin inhibitor is secreted in the pancreatic juice of the chick. Extracts from tissue have an inhibitor that corresponds to the secreted inhibitor on the basis of chromatography on DEAE-cellulose. The secretory inhibitor was purified by anion- and cation-exchange chromatography and by preparative isoelectric focusing. The purified inhibitor has 69 amino acids and is highly homologous with the secretory inhibitor from the turkey pancreas.

Structure of the 22-residue somatostatin from catfish. An O-glycosylated peptide having multiple forms.

The 22-residue somatostatin (SST-22) from channel catfish, purified by an improved method, is shown to be a glycopeptide. This represents the first report of a glycosylated somatostatin. Multiple forms of SST-22 exist with the major form containing 1 mol of galactose and 1 mol of N-acetylgalactosamine/mol of peptide attached via an O-glycosidic linkage to Thr-5. The position of the carbohydrate was determined by trapping the reactive peptide following beta-elimination of the carbohydrate with [35S]beta-mercaptoethanol followed by sequencing of the radiolabeled protein. All forms of SST-22 that have been purified are identical in amino acid composition. The heterogeneity resides in the carbohydrate portion of the glycopeptide with at least one of the minor forms containing sialic acid. The sequence for SST-22 obtained by automated Edman degradation is Asp X Asn X Thr X Val X Thr X Ser X Lys X Pro X Leu X Asn X Cys X Met X Asn X Tyr X Phe X Trp X Lys X Ser X Arg X Thr X Ala X Cys. This sequence differs at positions 5 and 19 from that published by Oyama et al. (Oyama, H., Bradshaw, R. A., Bates, O.J., and Permutt, A. (1980) J. Biol. Chem. 255, 2251-2254). The amino acid sequence reported here is identical to that deduced from the cDNA. The mass ion of SST-22 was determined by fast atom bombardment/mass spectrometry and shown to be 2943 +/- 1 (m/z). The observed mass ion is consistent with the molecular weight predicted from the amino acid sequence plus 1 mol of galactose and 1 mol of N-acetylgalactosamine.

The rachitogenic effects of fractions of rye and certain polysaccharides.

When fed to chicks rye is rachitogenic as well as growth depressing. The component or components of rye that cause these effects have not been identified. In an attempt to separate the factors, a water extract of rye was fractionated by precipitation with ethanol or ammonium sulfate. The precipitated fractions were fed to chicks. Although there were different responses to growth and bone ash from the ethanol fractions, they were not statistically significant. In another experiment, guar gum, pectin, or gum arabic was fed to chicks as 2% of the diet. Guar gum was both growth depressing and rachitogenic, pectin was only growth depressing, and gum arabic was without effect.

The effects of a pectic enzyme on the growth-depressing and rachitogenic properties of rye for chicks.

Rye has growth-depressing and rachitogenic properties when fed to chicks. Growth depression also is observed when chicks are fed certain polysaccharides, particularly pectin. Rye has about 8% pectin-like material. A commercially available pectic enzyme preparation was fed to chicks at .1% of the rye diet. This enzyme permitted better utilization of rye for growth and also alleviated the rachitogenic effects of rye. The supplemental enzyme permitted maximal bone mineralization with 200 to 300 ICU of vitamin D3/kg diet, whereas 500 ICU/kg otherwise were required with rye diets.

The effect of a purified guar degrading enzyme on chick growth.

Guar gum, a galactomannan, is growth depressing when fed to chicks. As part of the continuing studies on the mode of action of this and other gums in the intestine, a mannanase has been isolated which degrades guar gum. A commercial hemicellulase was separated into several protein fractions by chromatography on DEAE-cellulose. Only one of these proteins effectively reduced the viscosity of a guar gum solution. Activity towards pectin, rye water extract, and barley water extract was not present in the fraction which degraded guar gum but was found in other fractions at lower concentrations. Graded levels of this purified guar-degrading enzyme were incorporated into chick diets having 2% guar gum. This purified enzyme was effective at levels as low as .6 mg protein/kg diet in preventing growth depression caused by the guar gum and thus permitting growth equivalent to controls. Purity of this mannanase was confirmed by chromatography on QAE-Sephadex at pH 6.0 and by slab-gel electrophoresis at pH 8.4.

Effect of dietary cereal grain, citrus pectin, and guar gum on liver fat in laying hens and young chicks.

One laying hen and three chick experiments were conducted to study the effect of cereal grains, citrus pectin, and guar gum on liver fat of chicks and hens and on serum cholesterol of chicks. Feeding of wheat, rye, or 2% pectin in place of corn reduced liver fat content. The decrease in liver fat of hens fed wheat or rye was larger than that of those fed 2% pectin (P less than .05). The smallest amount of liver fat was found in livers of hens fed the rye diet. Wheat or pectin did not affect egg production of egg weight, but rye caused a significant decline in egg production in comparison with other treatments. Addition of 4% pectin or 2% guar gum to the corn control diet lowered liver fat, serum cholesterol (P less than .05), and body weight in chicks (P less than .05). Penicillin added to the diets containing 2% guar gum gave an increase in body weight (P less than .05) but had no effect on body weight of chicks fed diets containing 4% pectin. In contrast, pectinase prevented growth depression by pectin and guar gum. Pectinase also increased liver fat and serum cholesterol of birds fed the diet containing pectin or guar gum. When the corn control diet was pair-fed to the pectin diet, growth of the pair-fed chicks was better than that of the pectin-fed birds but was lower than that of birds fed the control diet ad libitium. Pectin-fed birds again had lower liver fat the serum cholesterol than the control birds. The reduced feed intake of chicks pair-fed the corn control diet had no effect on liver fat content.

Effect of gamma irradiation on nutritional value of dry field beans (Phaseolus vulgaris) for chicks.

The effect of gamma irradiation (60Co) of different varieties and breeding lines of dry field beans (Phaseolus vulgaris) on chick growth was determined using a chick growth assay in which the diet contained approximately 50% beans. Total protein (N X 6.25) in beans was not changed appreciably by irradiation (21 Mrad) but protein solubility in water was decreased. Irradiation increased in vitro enzymatic digestibility of bean protein by pepsin and by a mixture of trypsin, chymotrypsin and peptidase. In the bioassay the diet was formulated to derive half of the total protein (22.6%) from beans. Autoclaved Pinto and Pink beans gave significantly better growth than Red Mexican and White Pea beans. The differences between Red Mexican and White Pea beans were not significant except for Red Mexican breeding line number RS-59. The nutritional value of all varieties of beans, based on chick growth, was significantly improved by gamma irradiation. The irradiation treatment of beans tended to increase nitrogen retention by chicks and decrease uric acid nitrogen excretion in relation to nitrogen intake.