Utilization of N15-labelled urea in the laying hen. 5. N15-labelling of the content and tissue of separate parts of the gastrointestinal tract

In the series of experiments with labelled urea three colostomized laying hybrids were butchered after a six-day application of 1% urea with 96.06 atom-% 15N excess (15N') in the ration and another 2 days with a supplement of 1% unlabelled urea. Out of the individual samples from crop, gizzard, small intestine, caecum and rectum, the content of the small intestine and the caecum showed the highest labelling with greater than 1 atom-% 15N'. The TCA soluble fraction of the content of the gizzard was more highly and that of the intestines less labelled than the total nitrogen. The tissue of the gizzard is distinctly less labelled than the "omasum system" and the small intestine. The atom-% 15N' of the oesophagus with crop and glandular stomach largely showed agreement in the individual hens with that of intestinal tissue and ranged between 0.71 and 0.89 atom-%. 2% of the 15N' supplemented with the urea could be recovered in the content and the tissue of the gastro-intestinal tract.     

The substitution of lysine supplemented high protein wheat for protein feeds during the rearing and laying periods of hens. 8. Nitrogen excretion and true amino acid digestibility as an effect of various lysine levels and successive laying periods]

Digestibility trials were performed with laying hens receiving 3 types of rations containing equal proportions of the same dietary components. The percentage of high-protein wheat in these rations was 74%. Ration I was supplemented with 0.12% lysine while 0.06% lysine was added to ration II; ration III remained unsupplemented. The crude protein content of rations 1 to 3 was 16.1%, 16.5% and 16.6%, respectively. The corresponding lysine percentages were 0.66, 0.62 and 0.56. Studies were made to investigate the influence of different lysine levels on the rate of N excretion and various amino acid data. These studies were carried out during two successive laying periods. Only random differences between the data for urinary N excretion and N balances per kg liveweight were obtained in the two laying periods and for the different lysine levels. The true lysine digestibility was significantly lower in the poor-lysine ration as compared with the ration with 0.66% lysine. Moreover, the absorptive capacity for thio-amino acids is influenced by the lysine level of the ration. The proportion of lysine contained in faecal crude protein increased with the decreasing lysine content of the ration. Similarly, the total number of amino acids present in faecal crude protein increased with the declining supply of lysine. These findings suggest that relatively more NPN compounds are excreted in the faeces if adequate amounts of amino acids are supplied rather than when one amino acid is deficient.     

Substitution of protein feed through lysine-supplemented high-protein wheat during the rearing and laying period of hens. 3. Effect of graded lysine doses on the crude nutrient content of carcasses and on the level of amino acids and GOT activity in the blood of young hens]

A large-scale trial was carried out under commercial conditions to investigate to which extent the feeding of rations with varying lysine content to young hens would influence the crude nutrient content of the body fractions and might change the pattern of amino acid composition and the activity of GOT in the blood. Four rations were fed each containing 14.2% crude protein, 626-633 EFh units/kg and 0.59%, 0.61%, 0.54% and 0.46% lysine. The crude protein and crude fat content of the total body and of body fractions were in no case found to be related to the feeding regime. The proportion of crude ash in the "remainder of non-utilizable parts", in "bones", "intestinal and abdominal fat", "ovaries" and "small intestine" decreased with the decreasing lysine content of the rations. The concentrations of free lysine, histidine, arginine, and phenylalanine in the deproteinized blood plasma of the young hens were significantly (a = 0.01) lower in the birds of the lysine deficient group than in the hens of the other groups. Positive regressions were calculated for the lysine content or the content of aspartic acid in the ration and the pattern of free amino acids in blood plasma. Positive and negative linear relationships were found to exist between the concentrations of free lysine, and those of histidine, arginine or threonine, and serine. A close correlation existed between the total amount of essential amino acids in blood plasma and the lysine concentrations of the plasma. Increasing lysine supplementation produced a decline in the N content of the whole blood and blood corpuscles but a rise in the N content of blood plasma. The activity of GOT in the blood of young hens was not found to be useful as an indicator of the quality of dietary proteins.     

Unraveling the morphological patterns of a subantarctic eelpout: a geometric morphometric approach

Phenotypic variation in organisms depends on the genotype and the environmental constraints of the habitat that they exploit. Therefore, for marine species inhabiting contrasting aquatic conditions, it is expected to find covariation between the shape and its spatial distribution. We studied the morphology of the head and cephalic sensory canals of the eelpout Austrolycus depressiceps (4.5–22.5 cm TL) across its latitudinal distribution in South Pacific (45°S–55°S). Geometric morphometric analyses show that the shape varied from individuals with larger snout and an extended suborbital canal to individuals with shorter snouts and frontally compressed suborbital canal. There was size variation across the sampled populations, but that size does not have a clear latitudinal gradient. Only 8% of the shape variation relates to this size variation (allometry), represented by a decrease in the relative size of the eye, and a depression of the posterior margin of the head. There were spatial differences in the shape of the head, but these differences were probably caused by allometric effects. Additionally, 2 of the canals of the cephalic lateralis pores and the head shape showed modularity in its development. This study shows that the morphology of marine fish with a shallow distribution varies across distances of hundreds of kilometers (i.e., phenotypic modulation).     

Closed-shell molecules that ionize more readily than cesium

We report a class of molecules with extremely low ionization enthalpies, one member of which has been determined to have a gas-phase ionization energy (onset, 3.51 electron volts) lower than that of the cesium atom (which has the lowest gas-phase ionization energy of the elements) or of any other known closed-shell molecule or neutral transient species reported. The molecules are dimetal complexes with the general formula M2(hpp)4 (where M is Cr, Mo, or W, and hpp is the anion of 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine), structurally characterized in the solid state, spectroscopically characterized in the gas phase, and modeled with theoretical computations. The low-energy ionization of each molecule corresponds to the removal of an electron from the delta bonding orbital of the quadruple metal-metal bond, and a strong interaction of this orbital with a filled orbital on the hpp ligands largely accounts for the low ionization energies.     

The effect of straw meal on the crude protein and amino acid metabolism and the digestibility of crude nutrients in broiler breeding hens. 3. Digestibility of amino acids

In two experiments with colostomized broiler hens the influence of a straw meal supplement on the apparent digestibility of the amino acids of the ration and the 15N labelled basic amino acids in wheat was studied. In experiment 1 the animals received 120 g mixed feed plus 0, 20, 30 and 40 g straw meal per animal and day. The digestibility of the amino acids decreased on average from 86% to 83%, 80% and 79% with the growing straw intake. In contrast to the control variant, 20 g straw meal intake resulted in a significant decrease of digestibility for lysine, histidine, glycine, tyrosine, phenylalanine, cystine and methionine. 30 and 40 g straw meal reduced significantly the digestibility of all amino acids with the exception of arginine. The amino acid composition of the crude protein in faeces changed only very slightly due to the straw supplement. In experiment 2 15N labelled wheat was a component of the ration. Of the 15N labelled amino acids lysine, histidine and arginine, 88, 90 and 95% were apparently digested. The adaptation of the animals to straw meal intake did not change the digestibility of the amino acids.     

Metabolism of colostomized laying hens with 15N-labeled wheat. 3. Incorporation of 15N into and its distribution over follicles of various stages of development, the restovar and the oviduct

Of colostomised hens fed with labelled wheat protein the atom-% 15N-excess (15N') was ascertained in the bigger follicles, the restovar and the oviduct from the total N, the lysine-N, histidine-N and arginine-N. The labelling of the basic amino acids decreases the smaller the follicles are. In contrast to the yolk, in which a constant relation between the three amino acids was found, the relations were inconsistent and typical of the individual hens. In the atom-% 15N' in the three amino acids in the restovar and the oviduct there were greater differences between the hens. In the lysine, histidine and arginine we found, on an average, 21.2% of the total labelled N of the follicles.     

Studies on the use of wheat rich in crude protein in the feeding of broilers. 1. Experimental procedure, weight gains, food consumption and food efficiency]

A fattening trial was carried out with 8 groups of broilers each comprising 1225 birds. Within this trial tests were made to replace the protein feeds of newly hatched chicks over a period of up to 56 days of age, by wheat rich in crude protein. If wheat with a high crude protein content is fed supplementation with lysine and methionine will be necessary depending on the kind of protein feed used. No supplementation with amino acids is required if rations of fish meal + extracted soya bean meal are used despite their reduced content of these amino acids. The broilers consumed larger quantities of the wheat + extracted soya bean meal+fish meal ration than of the mixtures containing no fish meal. Food requirements per unit of weight gain were the same for the mixtures containing high-protein wheat and for the standard maize ration. The lowest food consumption per unit of weight gain was computed for the wheat + extracted soya bean meal diet supplemented with amino acids. The same quantities of lysine, thioamino acids and threonine were necessary for broilers receiving the wheat rations as for birds of the standard group. Protein feed may be saved by using high-protein wheat in the fattening of broilers. The rates of weight gain obtained with these rations are the same or even better than those achieved with rations of maize + fish meal+soya bean meal.