Showing papers on "Low protein published in 1974"
TL;DR: The results fail to support the view that degradation of urea in the gut promotes N conservation in uremic subjects maintained on low protein diets.
Abstract: Urea degradation was measured during 16 experiments in 13 chronic uremic patients being treated with essential amino acids or their analogues. [(14)C]Urea was injected i.v. and the clearance of labeled urea from its volume of distribution was compared with the simultaneous renal clearance of ordinary urea, which averaged 2.0 liters/day. The difference, extrarenal clearance of urea, averaged 3.1 liters/day as compared with a previously reported mean of 18 liters/day in normal subjects. Thus urea-splitting activity in the gut of uremic subjects expressed in these terms is far less than in normal individuals. Nevertheless, the amount of ammonia N formed from urea in these patients, 3.5 g/day, is not significantly different from normal, owing to their elevated plasma urea. In the same subjects, urea appearance rate was measured as the sum of urea excretion and the daily change in the urea pool. No negative correlation was noted between urea appearance and urea degradation, as might be expected if portal ammonia were being utilized for protein synthesis. However, urea production was positively correlated (r = 0.76) with urea degradation, suggesting that most of the resulting portal ammonia is converted back to urea. The results fail to support the view that degradation of urea in the gut promotes N conservation in uremic subjects maintained on low protein diets.
85 citations
TL;DR: F-actin filaments form a weak network in solution, which is easily destroyed by external force, according to structural viscosity and dynamic viscoelastic measurements.
66 citations
TL;DR: 3-Deoxy-arabino-heptulosonic acid 7-phosphate synthetase has been purified 1000-fold from cauliflower florets and exhibited high specificity for the substrates erythrose-4-P and P-enolpyruvate, andhibition of activity by a number of metal chelators indicates that the enzyme contains a metal ion important for activity.
65 citations
TL;DR: The rat liver enzyme does not appear to respond to "general metabolic pool inhibition" as a regulatory parameter, as has been suggested for PRPP synthetase from other sources, and minor degrees of inhibition occur with several thiopurine compounds.
47 citations
Journal Article•
TL;DR: Results support the conclusion that maternal dietary deficiency can adversely affect T-cell function in rat offspring.
Abstract: The progeny of mothers subjected to marginal lipotrope or moderately low protein diets exhibit deficient humoral immune responses. Serum antibody titres and numbers of antibody-forming cells to sheep erythrocytes (SRBC) are lower in the offspring of mothers whose diets were limited in either percentage protein or percentage lipotropes than in offspring whose mothers were fed a complete diet. Immune lymphocyte stimulation by SRBC antigens was marginal and not measurably different between the progeny of malnourished mothers and controls.
The in vitro response of spleen cells from offspring of nutritionally deprived mothers to the T-cell mitogen phytohaemagglutinin (PHA) is considerably less than that of controls. Thymus cells from marginal lipotrope offspring respond well to PHA, suggesting that PHA-reactive cell migration may be inhibited in these animals.
These results, obtained using a T-dependent antigen (SRBC) and a T-dependent mitogen (PHA), support the conclusion that maternal dietary deficiency can adversely affect T-cell function in rat offspring.
40 citations
TL;DR: The results were interpreted to indicate that when an excess of substrate was present, citrulline synthesis from NH(4)Cl was rate-limited by the intramitochondrial concentration of N-acetyl-glutamate, but citrulla synthesis from glutamate was Rate-limited primarily by the activity of the glutamate-transporting system.
Abstract: 1. Citrulline synthesis was measured in mitochondria from rats fed on a standard diet, a high-protein diet, or on glucose. 2. With NH 4 Cl as the nitrogen source the rate of citrulline synthesis was higher in mitochondria from rats fed on a high-protein diet than in those from rats fed on a standard diet. When rats were fed solely on glucose the rate of synthesis of citrulline from NH 4 Cl was very low. 3. With glutamate as the nitrogen source the relative rates of citrulline synthesis were much lower than when NH 4 Cl was present, but similar adaptive changes occurred. 4. The activity of the mitochondrial glutamate-transporting system increased two to three times on feeding rats on a high-protein diet, but the K m for glutamate was unchanged. 5. Adaptive changes in certain intramitochondrial enzymes were also measured. 6. The results were interpreted to indicate that when an excess of substrate was present, citrulline synthesis from NH 4 Cl was rate-limited by the intramitochondrial concentration of N -acetyl-glutamate, but citrulline synthesis from glutamate was rate-limited primarily by the activity of the glutamate-transporting system.
37 citations
TL;DR: The findings of the present investigation suggest that the development of renal hydrogen ion excretion capacity in preterm infants during the first weeks of life is related primarily to gestational age, and may respond to increased excretory needs imposed by dietary load.
Abstract: . Svenningsen, N. W. and Lindquist, B. (Department of Paediatrics, University Hospital, Lund, Sweden). Postnatal development of renal hydrogen ion excretion capacity in relation to age and protein intake. Acta Paediatr Scand,63:721, 1974.—The cumulative and maximum renal hydrogen ion excretion capacity after induced acidosis has been studied in six term and twenty preterm infants at 1–3 and 44 weeks of postnatal age corresponding to for preterm babies 34–36 and 37–39 and for term babies 41–43 and 44–46 weeks of gestational age. The maximum net hydrogen ion (H+NAE) excretion capacity is lower in preterm than in term infants at 1–3 weeks of postnatal life. However, when approaching full gestation there is a considerable increase of the H+NAE excretion capacity of pretem infants almost equal to that found in term infants at 1–3 weeks of age. High dietary protein intake lasting for in average two to three weeks in preterm infants does not change the maximum renal H+ excretion during induced acidosis, but significantly enhances the initial increment of excretion rate of titratable acid (H+TA) in comparison to preterm infants fed low protein diets. The findings of the present investigation suggest that the development of renal hydrogen ion excretion capacity in preterm infants during the first weeks of life is related primarily to gestational age. This development may, however, to a certain degree respond to increased excretory needs imposed by dietary load.
33 citations
TL;DR: On the basis of the relative concentration of axonal and Schwann cell plasma membranes in the nerve, the Na-K ATPase activities of the two membrane fractions and a comparison of the properties of the membrane fractions to those of squid and lobster nerve membrane preparations, fraction I seems to be the axonal membrane and fraction II the Schwanncell plasma membrane.
Abstract: Garfish Lepisosteus osseus olfactory nerve, because of its large size and the unusually high concentration of axonal membrane, is an excellent source of axonal membrane. A procedure is described for the isolation of two types of plasma membranes from the nerve which are obtained in yields of about 20 mg (fraction I) and 1.5 mg (fraction II) per g of wet nerve. Both membrane fractions consist mostly of rounded membrane vesicles, with a unit membrane thickness of ∼7.5 nm. The two membrane fractions are different in their lipid to protein ratios, Na-K ATPase activities, polypeptide patterns on sodium dodecyl sulfate (SDS) gel electrophoresis, and fatty acid compositions. They have similar phospholipid composition. On the basis of the relative concentration of axonal and Schwann cell plasma membranes in the nerve, the Na-K ATPase activities of the two membrane fractions and a comparison of the properties of the membrane fractions to those of squid and lobster nerve membrane preparations, fraction I seems to be the axonal membrane and fraction II the Schwann cell plasma membrane. Fraction I has a low protein to lipid ratio. Its polypeptide pattern on SDS gel appears to be much more complex as compared to that of fraction II membrane.
33 citations
TL;DR: It is suggested that kinetic and allosteric factors may be more important in controlling protein metabolism and amino acid cat abolism in fish than total enzyme level.
Abstract: In order to examine the effects of artificial diets at the tissue level, plaice (Pleuronectes platessa L.) were fed either high (50%) or low (20%) protein diets for several weeks and the total quantities of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), protein and phospholipid in their livers were measured. Alanine amino-transferase, aspartate aminotransferase, glutamate dehydrogenase and glucose-6-phosphatase activities in the livers were also measured. Similar measurements were made on the livers of wild plaice. The total amount of DNA in the livers of both cultured and wild plaice, of standard weight, did not differ significantly, irrespective of dietary history. In fish of standard weight, total hepatic RNA, protein and phospholipid levels were highest in the cultured fish fed high protein diet and lowest in the wild fish. These differences were related to dietary protein supply and environmental temperature. The total organ levels of the liver enzymes in plaice of equal weight were not significantly different in the cultured fish fed high and low protein diets. Wild-fish livers contained a smaller total amount of alanine aminotransferase, aspartate aminotransferase and glucose-6-phosphatase activity than did those of cultured fish. Total liver glutamate dehydrogenase activity was not significantly different in any of the fish examined. It is suggested that kinetic and allosteric factors may be more important in controlling protein metabolism and amino acid cat abolism in fish than total enzyme level.
32 citations
01 Jan 1974
TL;DR: Results indicate a high correlation of infection and retardation of growth and reproduction with the combined effect of Pb exposure and low protein diet.
Abstract: It has been noted that lead exposure affects reproduction in male rats. To study the combined effect of Pb and low protein diet on growth and sexual development of young rats, 50 21 day old male Sesco rats were divided into four groups and controlled dietetically. The group receiving low protein plus Pb exhibited a 20% death rate; the group on low protein diet alone exhibited a 10% death rate. Maximal blood Pb concentrations per group were: I (normal protein diet) 0.08 +- 0.02 (ppM +- SEM); II (normal protein + Pb) 0.68 +- 0.06; III (low protein diet) 0.36 +- 0.08 and IV (low protein + Pb) 11.31 +- 0.48. Group IV animals exhibited significant decreases in the weights of testes, prostates and seminal vesicles. No mature sperm were present in either testicles or epididymis. Results indicate a high correlation of infection and retardation of growth and reproduction with the combined effect of Pb exposure and low protein diet. 18 references, 14 figures, 3 tables.
30 citations
TL;DR: A sensitive method for measurement of adenylate cyclase activity in fat cell ghosts is described, using unlabelled ATP as substrate in the presence of an ATP-regenerating system containing 5 mM creatine phosphate and 0.1 mg creatine kinase per ml.
Abstract: A sensitive method for measurement of adenylate cyclase activity in fat cell ghosts is described; it applies the protein binding assay for cyclic AMP of Gilman (1970). Unlabelled ATP is used as substrate in the presence of an ATP-regenerating system containing 5 mM creatine phosphate and 0.1 mg creatine kinase per ml. Measurement of ATP levels showed that at least 80% of the substrate level is maintained during the standard assay procedure. Chromatographic separation of cyclic AMP can be omitted, since the high specificity of the binding protein allows a dilution of the samples below the concentrations at which ATP and other nucleotides interfere with the binding of cyclic AMP. Thus, the measurement of nM concentrations of cyclic AMP in the presence of mM concentrations of ATP is achieved. The main advantage of the method lies in the use of low protein concentrations; it reduces interfering effects of membrane-bound ATPases and phosphodiesterases. No precautions such as addition of phosphodiesterase inhibitors are needed, since cyclic AMP degradation is negligible during standard incubation conditions.
TL;DR: It appears that the lack of protein synthetic activity in unfertilized eggs is not due to the presence of a population of inhibited ribosomes, and it is apparent that sea urchin egg ribosome are functional at a level equivalent to or better than zygote ribosites.
TL;DR: In this article, a pilot-scale fractionation of 43% D.E. and sugar spectrum is described. But the results are limited to a single membrane filtration process and do not cover the entire spectrum.
Abstract: Glucose syrups, which are clear, aqueous solutions of malto-oligosaccharides and maltodextrins, are ideal materials for processing by reverse osmosis or ultrafiltration techniques. Hence membrane filtration methods, in their widest sense, can be used to achieve molecular separation of glucose syrup components without any particular technological difficulty.
This paper presents details of the pilot-scale fractionation of 43% D. E. acid-converted glucose syrup by passage through ‘loose’ and ‘tight’ cellulose acetate membranes, and changes of D. E. and sugar spectrum likely to be achieved on the basis of current knowledge. The very low protein concentrations encountered in commercial glucose syrups minimise difficulties of concentration polarisation which arise in many other applications. Viscosity problems do not arise below 30% w/v operating concentrations and the fractionation of glucose syrup by reverse osmosis appears to be more straightforward than its concentration by the same technique. Fractionation of glucose syrup by reverse osmosis offers a means for the manufacture of several new types of syrup, and enables entire groups of sugars to be eliminated under selected conditions. Products in the range 43–80% D. E. or 15–43% D.E. can be obtained using suitable combinations of different membranes, and the latter type by a single membrane filtration. Thus reverse osmosis may take its place as a unit operation of glucose syrup manufacture in the future.
TL;DR: The data re‐emphasise that protein concentration of laying hen rations can be reduced from the commonly used 15.5 and 16.5% levels to 14% without impairing productive performance, provided that rations based on wheat and soybean meal or corn and soybeans meal are supplemented with sufficient lysine and methionine.
Abstract: Synopsis Rations in which all the protein was supplied by wheat and soybean meal or corn and soybean meal were fed to White Leghorn hens for 252 d. Rations based on wheat‐soybean meal which contained 14% protein supported a high and efficient rate of egg production when supplemented with sufficient lysine and methionine to ensure minimum intakes of 600 and 300 mg per hen‐day, respectively. Similarly, corn‐soybean meal rations which contained 12 to 14% protein and were properly supplemented with methionine and lysine supported satisfactory laying hen performance. Average egg size of hens fed on rations based on wheat was slightly smaller than that of hens fed on corn‐based rations. Lysine supplementation did not alleviate this. The data re‐emphasise that protein concentration of laying hen rations can be reduced from the commonly used 15.5 and 16.5% levels to 14% without impairing productive performance, provided that rations based on wheat and soybean meal or corn and soybean meal are supplemented judicio...
TL;DR: Although restricted feeding during the laying period substantially reduced the food intake it also had a detrimental effect on the rat intake and variations in the laying performance of the different breeds appear to be dependent on the amount of protein fed in the first eight weeks of life.
Abstract: Synopsis Pullets from two commercial breeds were fed on diets of similar energy content but with 19% or 16% crude protein to 8 weeks of age and from 8 to 20 weeks of age on one of three isoenergetic diets containing either 12, 14 or 16% crude protein. At 20 weeks the birds were offered a conventional layers’ diet containing 16% crude protein either ad libitum or on a daily food intake of 100 g for a further 32 weeks. The results indicate that with certain breeds the dietary protein levels can be lowered to approximately 16% during the o to 8‐week period and to approximately 12% during the 8 to 20‐week period without adversely affecting egg production. However, variations in the laying performance of the different breeds appear to be dependent on the amount of protein fed in the first eight weeks of life. Significant breed effects were observed throughout the experiment and although restricted feeding during the laying period substantially reduced the food intake it also had a detrimental effect on the rat...
TL;DR: In this article, a standard flash desolventizing system was combined with horizontal agitated meal stripping and cooking vessels operating at atmospheric pressure to provide an integrated system for the production of high, intermediate, or low protein dispersability index edible soybean flakes from extracted solvent-wet flakes.
Abstract: A standard flash desolventizing system has been combined with horizontal agitated meal stripping and cooking vessels operating at atmospheric pressure to provide an integrated system for the production of high, intermediate, or low protein dispersability index edible soybean flakes from extracted solvent-wet flakes. Flash desolventizing removes most of the hexane in the wet flakes by evaporation at low temperature in a turbulent stream of superheated hexane vapor. The small remaining hexane quantity is removed in a stripping process capable of producing the full range of protein dispersability index values in the flakes by treating the flash desolventized flakes with either dry superheated steam or wet saturated steam under carefully controlled conditions of steam temperature, pressure, flow rate, and moisture content. The products are light colored, with little production of fine particles.
TL;DR: The results showed soybean meal to have the highest nutritional value of the materials tested, and Hyproly barley gave better growth and PER values than Piroline barley, but supplements of lysine and procaine penicillin made them equal.
TL;DR: The results indicate that in protein deficiency the cross-linking and maturation of collagen are impaired.
Abstract: To study the effect of protein deficiency on collagen cross-Unking in albino-rat skins and granulomas, two groups of weanling albino rats were raised for 3 weeks with normal and low protein diets by paired-feeding technique. The analysis of skins showed α1and α2-chain subunits of neutral salt-soluble collagen appreciably increased, β11- and β12-chains and the aldehyde content significantly decreased whereas the solubility of insoluble collagen in KCNS, urea or pronase increased greatly in protein-deficient animals compared to controls. The gel reversibility of neutral salt-soluble collagen increased in both skins and granulomas of protein-deficient animals compared to controls. The results indicate that in protein deficiency the cross-linking and maturation of collagen are impaired.
TL;DR: The results support the suggestion that in the first situation ( niacin-free diet ) the metabolic response is a result of a deficiency of niakin; whereas, when the tryptophan imbalance is induced in an adequate- niac in diet with 7.8% of an amino acid mixture devoid of tryptophile, the immediate metabolic need is that of tryPTophan, the limiting amino acid; a response typical of those observed with other amino acid imbalances.
Abstract: The concentration of free tryptophan and other free amino acids in blood plasma and of free tryptophan and threonine in liver and muscle have been determined in rats fed tryptophan-imbalanced diets ( induced with 7.8% amino acids in a low protein adequate-niacin diet or with threonine or 2.06% amino acids in a low protein niacin-free diet). The concentration of free tryptophan in the plasma and liver of rats fed the threonine-induced niacin-deficient diet was not depressed below that of the control animals. However, tryptophan concentration decreased in the plasma of rats fed the above diet corrected with 2.5 mg nicotinamide/100 g diet. Liver tryptophan concentrations, however, did not decrease in the niacin-corrected group. The only prominent change in other amino acids was that of threonine, which increased markedly in all groups supplemented with threonine. When the 7.8% amino acid-induced un balanced diet containing adequate niacin was fed, the plasma and muscle free trypto phan concentrations of meal-fed rats decreased markedly within 3.5 to 5 hours. Liver concentrations also decreased by 5 hours in the unbalanced group. The concentrations of the amino acids that were added to the diet to cause the imbalance increased con- comitantly with a decrease in plasma tryptophan. These results support the suggestion that in the first situation ( niacin-free diet ) the metabolic response is a result of a deficiency of niacin; whereas, when the tryptophan imbalance is induced in an adequate- niacin diet with 7.8% of an amino acid mixture devoid of tryptophan, the immediate metabolic need is that of tryptophan, the limiting amino acid; a response typical of those observed with other amino acid imbalances. J. Nutr. 104: 1584-1596, 1974.
TL;DR: Extremely low levels of dietary proteins seem to have had a promotive effect on the induction of atherosclerotic lesions by an atherogenic diet, whereas adequate levels of culinary proteins haveHad a protective influence.
TL;DR: Voluntary food intake of pigs fed diets varying from 0 to 15 per cent crude protein has been studied and there was a direct correlation between degree of protein depression and the decrease in plasma essential amino acid concentrations, but no such direct relationship existed for the non-essential amino acids.
TL;DR: Under reversal conditions for centrally located cues, low protein subjects were found to perform at significantly lower levels than the high protein controls and these results are consistent with both a visual sampling model of attention and a number of two-stage models of attention.
TL;DR: Optimal conditions for analyses of the molecular weight of myosin were used in the following studies for determination of the Molecular weight of canine cardiac left and right ventricular myosins.
TL;DR: Low protein Giovannetti diets in patients with chronic renal failure have been compared with isonitrogenous, iso-caloric amino acid tablet-substituted regimes and it is suggested that when the caloric supply is adequate for generation of sufficient α-ketonic acid derivatives, ammonia nitrogen is preferentially utilized for the synthesis of non-essential amino acids rather than more urea formation.
Abstract: Low protein Giovannetti diets in three patients with chronic renal failure have been compared with isonitrogenous, iso-caloric amino acid tablet-substituted regimes. Another patient has been managed on such a regime after regular haemodialysis treatment had to be suspended. The amino acid diets proved palatable and were effective in maintaining nitrogen balance when the caloric supply was adequate. Improved nitrogen balance correlated with diminished faecal nitrogen excretion and falling or stable blood urea levels implying improved urea nitrogen re-utilization. It is suggested that when the caloric supply is adequate for generation of sufficient α-ketonic acid derivatives, ammonia nitrogen is preferentially utilized for the synthesis of non-essential amino acids rather than more urea formation. Metabolic acidosis is a potential hazard of such regimes.
TL;DR: The decrease in the T/2 Rbc and the sensitivity to a hemolytic agent (lysolecithin) of cells of rats on low protein or protein-free diet observed in this study may be related to the mechanism of anemia during inadequate protein nutrition.
Abstract: Studies were made on the effects of splenectomy on the red cells of rats receiving various dietary levels of protein. Anemia was pronounced and the survival time of red cells (T/2 Rbc) was reduced in rats on a protein-free diet as compared with rats on standard and low protein diets. The spleen appeared to be relatively hypofunctional in rats on low protein diets since (a) splenectomy had the least effect on increasing T/2 Rbc in rats on low protein diet and largest effect on survival of Rbc's in rats on a normal diet; (b) splenectomy had the least effect on osmotic fragility of red cells in rats on low protein diet and the most effect was shown on osmotic fragility of rats on normal diet; (c) the weight of the spleen was least in rats on a low protein diet in comparison with the other two groups. The red cells of normal rats on a protein-free diet were most sensitive to lytic effect with lysolecithin, and Rbc's from splenectomized rats were more resistant to osmotic lysis than Rbc's from intact rats. The decrease in the T/2 Rbc and the sensitivity to a hemolytic agent (lysolecithin) of cells of rats on low protein or protein-free diet observed in this study may be related to the mechanism of anemia during inadequate protein nutrition.
TL;DR: The expression of the methionine concentrations in this manner provides a useful means of predicting the hen’s response to Methionine supplementation under different conditions if the resulting concentrations can be compared with a reference diet known to respond to methionin additions.
TL;DR: It was concluded that the level of protein deprivation induced in this study depletes the animals' energy resources and produces a lowered anxiety threshold, so that certain additional behavioral demands cannot be supported even though routine cage activities are not impaired.
Abstract: Three groups of adult female rhesus monkeys, maintained on low-protein diets (.5-gm, 1-gm, and 2-gm protein per kg body weight) were compared with a control group (4-gm protein per kg body weight) on a number of spontaneous cage activities and chain-pulling behavior. Although the deprived animals lost body weight and muscle tissue and they became deficient in essential amino acids and plasma albumin, they maintained their normal posture and continued to move about, vocalize, eat, drink, etc., as such monkeys usually do in their home cages. However, several specific behavioral deficiencies were revealed: reduced face and head movements, fewer eye contacts, and less chain pulling. It was concluded that the level of protein deprivation induced in this study depletes the animals' energy resources and produces a lowered anxiety threshold, so that certain additional behavioral demands cannot be supported even though routine cage activities are not impaired.
01 Jan 1974
TL;DR: In this paper, positive correlations have been found between yield and grain protein concentration in grain sorghum, and the problem of low protein levels appears to be associated particularly with high-yielding hybrid cultivars.
Abstract: Negative correlations have been found to exist between yield and grain protein concentration in grain sorghum, and the problem of low protein levels appears to be associated particularly with high-yielding hybrid cultivars . .Solution culture experiments with the hybrid Texas 610 showed that the effects of nitrogen deficiency oli grain yield are are greatest when the deficiency occurs early in the growing season; the magnitude of the effect .. ranking: pre-head. initiation_;> initiation to anthesis>post-anthesis. By contrast large and consistent effects of nitrogen deficiency on grain protein concentration were observed only when the deficiency was imposed between anthesis and maturity. In the field, nitrogen supply was shown to. have large effects on both yield0.8 to 9.2 tonnes/ha and on grain protein concentrations (6.6 to 18. 9o/o), low yields being associated with exhaustion of plant available nitrogen during the early part of the season, and low protein concentrations with nitrogen shortage during the latter part of the season. It is concluded that the desired objectives of high yield and satisfactory grain protein concentrations can be achieved if care is taken to ensure that adequate nitrogen is available to the crop throughout the growing season up to and including the grain filling stage.
01 Jan 1974
TL;DR: Poor quality spear grass was fed to cattle without prior treatment, or after treatment with potassium hydroxide and addition of urea and sodium sulphate, causing significant increases in the digestibility of organic matter and cell wall constituents, and in organic matter intake.
Abstract: Summary Poor quality spear grass was fed to cattle without prior treatment, or after treatment with potassium hydroxide and addition of urea and sodium sulphate. Treatment caused significant increases in the digestibility of organic matter and cell wall constituents, and in organic matter intake; as a result, calculated metabolizable energy intake rose by 51% to well above maintenance. The results are discussed in terms of the nutritional deficiencies of cattle during seasonallydry periods of the year. I. INTRODUCTION The short growing season of many pasture plants in northern Australia forces cattle to graze mature forage for much of the year. During such times grasses in particular consist mainly of cell wall with a small proportion of cell contents. The low nutritional quality of the resulting forage, characterized by high fibre, low protein and low digestibility, is well known (Milford 1960). More recently the specific inadequacies of some species (e.g. Playne and Haydock 1972) and their poor utilization by both cattle and sheep (Siebert and Kennedy 1972) have been demonstrated. Selection of new pasture species which demonstrate adaptation to the area during the dry season is in progress (Burt et al. 1970). Currently, however, nonprotein nitrogen supplements are being used to minimise weight loss of the grazing stock during the seasonally-dry period of the year (e.g. Winks, Alexander and Lynch 1970). In specific circumstances additions of nitrogen and sulphur to poor quality spear grass have increased feed intake to above maintenance requirements (Siebert and Kennedy 1972). Results with supplements are generally inconsistent. One probable reason is the wide variations in pasture composition both within and between years. Because of the high fibre content of dry season roughage, sufficient energy may not be available for optimum microbial activity in the rumen. The experiment reported here analyses the effect firstly that potassium hydroxide treatment has on subsequent digestion and secondly that this treatment, with addition of nitrogen and sulphur, has on metabolizable energy intake. Alkali digestion of roughages has been carried out for many years, but more recently spraying techniques that avoid washing have been attempted (Ololade, Mowat and Winch 1970; Hogan and Weston 1971; Fernandez Carmona and Greenhalgh 1972). The subject of alkali treatment and steam processing of lignocellulose material for ruminant use has been discussed by Pigden and Bender (1972). The results of treatment are discussed in terms of the nutritional limitations of cattle grazing poor quality pasture ,vation procedures