scholarly journals The Influence of Abomasal Supplements of Some Amino Acids and Sulphur-Containing Compounds on Wool Growth Rate

1970 ◽  
Vol 23 (2) ◽  
pp. 441 ◽  
Author(s):  
PJ Reis

Effects on wool growth rate of abomasal supplements of several amino acids (glycine, glutamic acid, arginine, lysine, and threonine) and of some sulphurcontaining compounds (L-cysteamine, sulphuric acid, and methionine hydroxy analogue) were examined. None of the abomasal supplements, apart from methionine hydroxy analogue, was effective for stimulating wool growth. Methionine hydroxy analogue did not influence wool growth rate when given as a dietary supplement.


1967 ◽  
Vol 168 (1013) ◽  
pp. 421-438 ◽  

The uptake of thirteen essential amino acids by mouse LS cells in suspension culture was determined by bacteriological assay methods. Chemostat continuous-flow cultures were used to determine the effect of different cell growth rates on the quantitative amino acid requirements for growth. The growth yields of the cells ( Y = g cell dry weight produced/g amino acid utilized) were calculated for each of the essential amino acids. A mixture of the non-essential amino acids, serine, alanine and glycine increased the cell yield from the essential amino acids. The growth yields from nearly all the essential amino acids in batch culture were increased when glutamic acid was substituted for the glutamine in the medium. The growth yields from the amino acids in batch culture were much less at the beginning than at the end of the culture. The highest efficiencies of conversion of amino acids to cell material were obtained by chemostat culture. When glutamic acid largely replaced the glutamine in the medium the conversion of amino acid nitrogen to cell nitrogen was 100 % efficient (that is, the theoretical yield was obtained) at the optimum growth rate (cell doubling time, 43 h). The maximum population density a given amino acid mixture will support can be calculated from the data. It is concluded that in several routinely used tissue culture media the cell growth is limited by the amino acid supply. In batch culture glutamine was wasted by (1) its spontaneous decomposition to pyrrolidone carboxylic acid and ammonia, and (2) its enzymic breakdown to glutamic acid and ammonia, but also glutamine was used less efficiently than glutamic acid. Study of the influence of cell growth rate on amino acid uptake rates per unit mass of cells indicated that a marked change in amino acid metabolism occurred at a specific growth rate of 0.4 day -1 (cell doubling time, 43 h). With decrease in specific growth rate below 0.4 day -1 there was a marked stimulation of amino acid uptake rate per cell and essential amino acids were consumed increasingly for functions other than synthesis of cell material.



1974 ◽  
Vol 52 (4) ◽  
pp. 719-726 ◽  
Author(s):  
E. L. Camm ◽  
J. R. Stein

Nitrate-reducing ability, NO2−-reducing ability, and glutamic acid dehydrogenase levels were measured in two clones of Nodularia spumigena Mertens. Measurements with whole cells of both clones show that NO3− reduction is stimulated by NO3−, and that NO2− reduction is probably stimulated by NO2−. The NO3−-reducing system is stimulated by light and inhibited by NH4+. These controls and possible control over NH4+ incorporation into amino acids are compared to systems operative in other organisms.Differences in growth and physiology of the clones in growth rate on N-free medium, growth inhibition by urea, and NO2− accumulation in the medium are discussed.



1974 ◽  
Vol 25 (6) ◽  
pp. 919 ◽  
Author(s):  
PJ Reis ◽  
DA Tunks

Sheep receiving a diet consisting solely of wheat (500 g/day), supplemented with a mineral mixture, were given abomasal infusions of varying amounts of DL-methionine (1.5–6.0 g/day) or of L-cystine (5 g/day). Other sheep received DL-methionine as a supplement to a roughage diet. All levels of methionine infused caused a decrease in the mass of wool grown by sheep consuming the wheat diet. This effect was greatest with 6 g methionine and was due mainly to a considerable depression of fibre diameter. Smaller amounts of methionine decreased fibre diameter and increased length growth rate. The infusion of methionine caused a considerable weakening of the wool grown by most of the sheep, with the result that a 'break' was observed in the fleece after about 1 week of methionine administration. This effect occurred with all levels of methionine but was more pronounced with 6 g/day. The abomasal infusion of cystine (5 g/day) caused little change in the mass of wool grown, but fibre diameter was decreased slightly. There were no appreciable effects on the strength of wool fibres and no wool was shed. Supplementation of the roughage diet (400 g/day) with methionine at 2 g/day stimulated wool growth, whereas with 6 or 10 g/day the mass of wool grown was unchanged but fibre diameter was markedly reduced. The strength of wool fibres was not markedly influenced by methionine infusions on this diet. The levels of amino acids in blood plasma and in abomasal digesta indicated that the mixture of amino acids absorbed was similar with both the roughage and the wheat diets.



1972 ◽  
Vol 25 (5) ◽  
pp. 1057 ◽  
Author(s):  
PJ Reis ◽  
WF Colebrook

Proteins of different amino acid composition (Promine-D, wheat gluten, and zein) were given as abomasal infusions to sheep and effects on wool growth rate, body weight gain, and nitrogen retention were compared with those of casein. These results were considered together with earlier data obtained for whole egg protein, egg albumen, maize gluten, and gelatin. The nutritive value of bloodmeal supplements was also studied. In addition the effects on wool growth of adding lysine and tryptophan to zein, and of adding leucine to casein, were examined.



1978 ◽  
Vol 90 (1) ◽  
pp. 173-183 ◽  
Author(s):  
P. J. Reis ◽  
D. A. Tunks

SUMMARYMerino sheep were given abomasal infusions of either mixtures of amino acids or protein during periods of 8 or 12 days. Effects on wool growth were measured using autoradiography and a clipping procedure which allowed time for the emergence of the wool fibres. Estimates of volume growth rate, from the autoradiographic measurements, and of mass of wool grown, from clipping, were in good agreement.An infusion of a standard mixture of 13 amino acids, which included ten essential amino acids in approximately the proportions in casein, consistently stimulated wool growth. The mean increases in volume and mass of wool grown, during 30 infusions, were 66 and 67% respectively. A mixture of ten essential amino acids alone appeared to be as effective as the standard mixture for stimulating wool growth, and there were no significant differences between the effects on wool growth of casein and the standard mixture of amino acids.The omission of methionine from an infusion of the standard mixture of amino acids, or from a mixture of essential amino acids only, inhibited wool growth rate; both fibre diameter and length of wool grown per day were reduced to below the control values. In addition, the strength of the fibres was considerably reduced.Infusions of zein and of an amino acid mixture simulating the essential amino acid composition of zein both inhibited wool growth rate, due to a reduction in fibre diameter. Similar effects on wool growth were observed when any one of three essential amino acids (lysine, isoleucine or leucine) was omitted from an infusion of the standard mixture of amino acids. The omission of five other essential amino acids (arginine, histidine, phenylalanine, threonine or valine) from the infusion, or variations in the proportions of leucine, lysine or methionine, had no appreciable effects on wool growth.



1951 ◽  
Vol 29 (3) ◽  
pp. 246-259 ◽  
Author(s):  
D. S. MacLachlan ◽  
F. S. Thatcher

The nutritional requirements of Corynebacterium sepedonicum (Spiek. and Kott.) Skapt. and Burkh. were investigated by the use of the Warburg respiration apparatus. Pantothenic acid, in a concentration of 600 micrograms (μgm.) per liter, caused the greatest growth augmentation of nine vitamins tested. The amino acids, glutamic acid, asparagine, leucine, and lysine in concentrations of 0.001, 1. 0, 0.03, and 0.03 gm. per liter respectively, caused a marked increase in oxygen uptake, either individually or in combination. Yeast nucleic acid and thymonucleic acid had no significant effect on the growth rate of C. sepedonicum. A new medium was prepared for the isolation and maintenance of C. sepedonicum.



1970 ◽  
Vol 23 (4) ◽  
pp. 1077 ◽  
Author(s):  
RN Murdoch

Intravenous or intraperitoneal infusions of either L-cysteine (2, 0 gjday) or L-methionine (2�5 gjday) for 20 days increased wool diameter and its length growth rate, the main increases occurring during the first 8 days of infusion. Thus parenteral administration of these amino acids is effective in stimulating wool growth.



1976 ◽  
Vol 86 (3) ◽  
pp. 475-482 ◽  
Author(s):  
P. J. Reis ◽  
D. A. Tunks

SummaryMerino sheep were given abomasal infusions of (i) zein (80 g/day), (ii) zein (80 g/day) supplemented with L-lysine (6 g/day), L-tryptophan (1 g/day) or lysine and tryptophan together, or (iii) L-leucine (20 g/day). Effects on wool growth (length growth rate, fibre diameter, fibre volume growth rate and mass of wool grown) and on plasma amino acids were measured.Zein increased length growth rate and decreased fibre diameter; on average the volume growth rate and mass of wool grown were not significantly altered. The addition of tryptophan to the infusion of zein did not significantly alter wool growth, whereas the addition of lysine significantly increased all aspects of wool growth. The responses to these treatments were rapid and were adequately assessed during 12-day infusion periods. The infusion of leucine did not cause any appreciable changes in wool growth.Leucine supplementation increased the concentration of leucine in blood plasma about six-fold. Zein decreased the concentration of lysine and ornithine in plasma and increased the concentration of several essential amino acids; leucine was increased about seven-fold. The addition of tryptophan to zein had no effects on plasma amino acids, whereas lysine decreased the concentration of several amino acids in plasma and markedly increased lysine.



1973 ◽  
Vol 26 (1) ◽  
pp. 249 ◽  
Author(s):  
PJ Reis ◽  
DA Tunks ◽  
AM Downes

Various amounts (0�6-10�0 g/day) of L-cystine, L-cysteine, and L- and DL-methionine were given as abomasal or intravenous infusions to 10 sheep, in three experiments.



1978 ◽  
Vol 29 (5) ◽  
pp. 1057 ◽  
Author(s):  
PJ Reis ◽  
DA Tunks

The effectiveness of mimosine as a chemical defleecing agent was assessed in adult sheep that were subjected to a variety of nutritional treatments prior to administration of mimosine, and in lambs receiving relatively high feed intakes. Mimosine was given as a continuous intravenous infusion over a period of 2 days. Sheep receiving 600 g of a roughage-based diet per day were consistently defleeced following an infusion of mimosine at the rate of 80 mg/kg/day (designated the standard infusion). The prior feeding of a reduced intake of this diet (300 g/day) did not alter the amount of mimosine required to defleece sheep. Likewise, the prior abomasal infusion of an imbalanced mixture of amino acids, which depressed the wool growth rate, did not allow defleecing with a reduced amount of mimosine. A 4-day fast, commenced 3 days before the start of mimosine infusion, approximately halved the amount of mimosine required to defleece sheep. The provision of a high intake of energy, together with large amounts of amino acids available for absorption from the small intestines (supplied by casein), for at least 1 week prior to mimosine infusion, completely prevented defleecing with the standard infusion of mimosine. The effects of these nutritional treatments could be obviated by a 4-day fast as described above. Also, increasing the rate of infusion of mimosine to 120 mg/kg/day largely overcame the effects of previous high nutrition. Relatively greater amounts of mimosine were required to defleece lambs than adults. The concentration of mimosine in plasma was related to the rate of infusion of mimosine. However, fasting and a low dietary intake tended to enhance the concentration of mimosine in plasma for a given rate of infusion. Infusion of mimosine at the standard rate resulted in plasma mimosine concentrations of the order of 100 µmoles/l, but this concentration did not ensure that defleecing would be possible.



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