The digestion of pasture plants by sheep. IV*. The digestion of Phalaris tuberosa at different stages of maturity

1969 ◽  
Vol 20 (5) ◽  
pp. 925 ◽  
Author(s):  
JP Hogan ◽  
RH Weston ◽  
JR Lindsay

A study was made of the composition, intake, and digestion of dried Phalaris tuberosa forage that had been harvested at three stages of maturity. Advancing maturity was associated with: (i) decreased food intake; (ii) increased expenditure of time and energy in chewing activities; (iii) decline in the rate of flow of digesta from the abomasum though not from the rumen; (iv) decline in digestibility in the whole tract of organic matter, nitrogen, and the structural carbohydrates; (v) decline in the digestion of fibre in the rumen relative to that occurring in the whole tract; (vi) decline in the quantities of volatile fatty acids and amino acids made available to the animal. By contrast only small differences attributable to maturity were observed in: (i) the distribution of digestion of organic matter between stomach and intestines; (ii) the digestibility of nitrogen other than ammonia in the intestines; (iii) the proportions of digestible organic matter derived from volatile fatty acids and amino acids; (iv) the proportions of individual amino acids in the digesta passing to the intestine. It was calculated that microbial piotcin contributed 33, 38, and 47% of the protein passing from the stomach to the intestincs with the diets of advancing maturity. Most of the remaining protein was presumably of dietary origin. About 80% of the crude protein in the digesta was present in the form of amino acids, and the quantities of amino acids released in the intestines were calculated to be equivalent to 64–66 g/100 g crude protein intake. With advancing maturity of the diets the plasma levels of the essential ammo acids except lysine, histidine, and arginine declined; there was little effect of diet on the plasma levels 01 non-essential amino acids. However, relative to total essential amino acids, the ratios of valine and leucine decreased with advancing maturity of the diet while those of lysine, histidine, glutamate, glycine, alanine, and serine increased. * Part 111, Aust. J. Agric. Res., 1969, 20, 347.

2012 ◽  
Vol 554-556 ◽  
pp. 1553-1558
Author(s):  
Sheng Jun Chen ◽  
Lai Hao Li ◽  
Xian Qing Yang ◽  
Bo Qi ◽  
Yan Yan Wu ◽  
...  

The nutritional components in the cuttlefish muscle were analyzed and the nutritive quality was evaluated in the paper. The results showed that the contents of the cuttlefish muscle in crude protein, crude fat, carbohydrate were 16.60%, 0.86%, 1.30%, respectively. There were 18 kinds amino acids and the total amino acids reached 17.44%, with an essential amino acid index(EAAI) of 67.95. The composition of the essential amino acids in muscle ratio was consistent with the FAO/WHO standards. In addition, the contents of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids were 41.13%, 12.15% and 46.72%, respectively. And the muscle contains a higher content of EPA and DHA, reached 11.0% and 24.49%, respectively. It was considered that the cuttlefish muscle has a high nutritive value and it can be the important material of the high quality protein and unsaturated fatty acid.


1980 ◽  
Vol 94 (1) ◽  
pp. 219-227 ◽  
Author(s):  
C. G. Wernli ◽  
R. J. Wilkins

SummaryGrass silage (21.0 % D.M.) was given ad libitum to sheep together with supplements of rolled barley, dried-grass pellets or dried-grass wafers at 12 and 25 g organic matter (OM)/kg0·75.Intake of silage was greater with supplement at 12 g/kg0·75 but total intake of OM and digestible organic matter (DOM) increased with increasing supplement. Intake of OM was higher with the pellet supplement than with other supplements. Intake of DOM, however, did not differ between the pellet and barley treatments, but was lower with wafers.Concentrations of ammonia and total volatile fatty acids and the molar proportions of butyric and higher volatile fatty acids were higher when silage was supplemented with barley than with dried grass. Mean rumen retention times of silage and of supplement were highest in the barley-supplemented treatments. Dried-grass wafers were retained longer than dried-grass pellets. Supplement treatments did not differ significantly for eating and ruminating times, rumen fluid volume and pH, digestion rate in the rumen and nitrogen retention.At the low supplement rate silage consumption may have been controlled by factors associated directly with the silage, whereas at the high rate intake was limited either by physical factors or by the potential energy demand of the animals.


1971 ◽  
Vol 22 (3) ◽  
pp. 461 ◽  
Author(s):  
GJ Faichney ◽  
RH Weston

Digestion of a diet containing 10% casein, either untreated or treated with formaldehyde, was studied in crossbred wether lambs. The treatment prevented breakdown of the casein in rumen liquor in vitro. There was a highly significant decrease in organic matter digestion in the rumen when the treated casein diet was given to the lambs. This was accounted for by increases in the amounts of protein and starch passing to the intestines. There was a 60 % increase in the amount of non-ammonia nitrogen and a 55 % increase in the amount of starch digested in the intestines. The concentrations of volatile fatty acids and ammonia in the rumen were significantly lower. There were increases in the plasma levels of insulin and �-amino nitrogen and a decrease in the plasma urea level in response to the treatment.


1969 ◽  
Vol 20 (2) ◽  
pp. 347 ◽  
Author(s):  
JP Hogan ◽  
RH Weston

A comparison has been made of the composition, intake, and digestion of forage oats grown with and without the application of nitrogen fertilizer and harvested at three stages of maturity. The chemical composition of the forages showed the usual changes with maturity. Fertilizer application had little effect on the levels of cell wall constituents but, as expected, decreased the levels of soluble carbohydrate and increased those of total nitrogen, alcohol-soluble nitrogen, and nitrate. The digestibility of organic matter, cell wall constituents, and nitrogen declined with advancing maturity, all three parameters being little affected by the fertilizer treatment. Feed consumption declined only with the most mature diet and was not affected by the fertilizer treatment even though the high nitrogen (HN) diets supplied 4–5 g nitrate nitrogen per day and relatively small amounts of soluble carbohydrate. There was a loss of dietary nitrogen from the stomach with the HN diets and a gain with the low nitrogen (LN). The amount of nitrogen in the digesta leaving the stomach per unit intake of nitrogen increased with maturity. The quantities of protein leaving the stomach were too great to be accounted for as microbial protein, and hence appreciable quantities of plant protein must have passed through the stomach. The digestibility of crude protein in the intestines was not affected either by maturity of the forages or by fertilizer treatment. There was little effect of advancing maturity or fertilizer application on: (a) the extent of digestion of organic matter and the structural carbohydrates in the stomach relative to that occurring in the intestines; (b) the proportion of digestible organic matter derived from rumen volatile fatty acids and amino acids; � the potential value of the metabolizable energy from volatile fatty acids and amino acids to provide net energy for fattening; (d) most parameters associated with the movement of digesta through the stomach. Advancing maturity of the diets was associated with increased expenditure of time in chewing activities.


1974 ◽  
Vol 25 (6) ◽  
pp. 1015 ◽  
Author(s):  
PM Kennedy

The effect of additions of sulphateh to the diet of cattle given tropical spear grass (Heteropogon contortus) and Townsville stylo (Stylosanthes humilis) was studied in three experiments. In one experiment there was a small increase in the digestibility of dry matter, but the intake of feed was not affected. The concentration of volatile fatty acids in ruminal liquor from cattle offered spear grass was increased by supplemental sulphate; there was a concurrent small decrease in the proportions of propionic and isovaleric acids. Excretion of faecal sulphur varied with the intakes of total sulphur, organic matter, and digestible organic matter, while urinary sulphur excretion varied with the sulphur and organic matter intakes. Excretion of organic sulphur and total sulphate in urine and faeces increased with sulphur intake. The ratio of nitrogen to sulphur in faeces declined when sulphate was given. The retention of nitrogen was correlated with sulphur retention. It was concluded that the intake and digestion of the hays were not limited by the intake of sulphur.


1975 ◽  
Vol 26 (5) ◽  
pp. 909 ◽  
Author(s):  
AR Egan ◽  
DJ Walker ◽  
CJ Nader ◽  
G Storer

Movement of digesta through the reticulorumen and through the intestines has been studied for four roughage diets (wheaten straw, ws; wheaten hay, WH; lucerne hay, LH; dried subterranean clover, sc; all in chopped form) given to sheep fitted with re-entrant duodenal cannulas. The extent and tbe sites of digestion of plant organic matter and its constituent soluble sugars, polysaccharides, pectin, and protein are described for the four roughages. Sugars, water-soluble polysaccharides and pectin were completely digested on all diets, almost entirely in the stomachs. Together these fractions contributed 16, 21, 25 and 27% of the apparently digested organic matter respectively for ws, WH, LH and sc diets. The digestibility of hemicellulose ranged from 49.5% (WH) to 80.9% (sc); of the hemicellulose digestcd, from 70% (WH) to 81 % (sc) was apparently fermented in the reticulorumen. The digestibility of cellulose ranged from 58 % (WH) to 88 % (sc), and of the cellulose digested, 83 % (WH) to 89 % (sc) was apparently fermented in the reticulorumen. Together, apparently fermented cellulose and hemicellulose contributed from 25 %: (sc, LH) to 55 % (ws) of apparently digested organic matter. Despite evidence of nitrogen loss across the reticulorumen on thee two high nitrogen diets (LH, - 10 %; sc, - 22 %) and net gains in nitrogen on the two lower nitrogen diets (ws, + 50 %; WH, +20%), the yield of all amino acids at the duodenum per 100 g digestible organic matter intake was about 50 % higher for LH and sc (which were similar) than for ws and WH (which were similar). The relative proportions of essential amino acids did not change significantly. Nutritional implications of these changes in the site of digestion and of the proportions of nutrients released to the animal are discussed.


1968 ◽  
Vol 19 (3) ◽  
pp. 419 ◽  
Author(s):  
RH Weston ◽  
JP Hogan

The production of volatile fatty acids (VFA) in the rumen of sheep was estimated by isotope dilution techniques. The 12 diets used consisted of dried ryegrass and forage oats and covered a wide range of levels of cell wall constituents (46–40% of the organic matter), crude protein (6–32%), and soluble carbohydrate (5–18%). Each diet was offered at a level equal to approximately 90% of the sheep's ad libitum intake. The production of VFA was correlated with the total amount of organic matter digested in the alimentary tract (r = 0.93–0.95). The mean VFA production per 100 g of organic matter digested in the alimentary tract was equivalent to 56.8 g, 243 kcal, or 0.85 mole. Values for individual diets varied about these means with a coefficient of variation of 6–7%. Rates of VFA production in, and VFA absorption from the rumen were correlated with VFA concentration in rumen liquor (r = 0.67, r = 0.67) and the rumen VFA pool (r = 0.81, r = 0.79). Approximately 76% of the VFA produced in the rumen was absorbed from the rumen, 19% was absorbed from the omasum and abomasum, and 5% passed from the abomasum to the intestines.


1971 ◽  
Vol 22 (1) ◽  
pp. 139 ◽  
Author(s):  
RH Weston ◽  
JP Hogan

Subterranean and berseem clovers, harvested at early and late stages of maturity, were dried and offered to sheep ad libitum, or at about 90 % of ad libitum intake. Feed consumption and the times spent in ruminating and eating were measured when the forages were offered ad libitum and several aspects of digestion were studied at the restricted level of feeding. The effects of maturity on (i) forage chemical composition, (ii) nutrient digestibility, (iii) parameters relating to the movement of digesta through the stomach, (iv) ruminal volatile fatty acid production, (v) the molar proportions of individual amino acids in abomasal digesta and peripheral blood plasma, (vi) nitrogen balance, and (vii) the time and energy expenditure in ruminating and eating, were generally the same with these clovers as has been observed previously with grasses. Substantial amounts of nutrients were derived from forages harvested in the immature state, the consumption of which provided about 1200 g organic matter per day. It was calculated that under conditions of ad libitum feeding about 500 g of volatile fatty acids was produced in the rumen and 160-230 g of crude protein was digested in the intestines per day. High mean values for nitrogen balance were obtained with immature subterranean clover but the variation between sheep was large. The levels of amino acids in blood plasma were also exceptionally high with this diet. The data obtained on the digestion of immature clover forages were compared with those obtained previously with immature grass forages. The patterns of digestion were generally very similar for both types of forages and any differences observed could usually be ascribed to the higher feed intake with the clovers. The forages had similar capacities to furnish volatile fatty acids in the rumen and digested crude protein in the intestines. The calculated energy expenditure in eating and ruminating, however, was slightly lower for the clovers. The data were interpreted to indicate that if immature clovers are superior to immature grasses in promoting animal production, the superiority cannot be attributed to an inherent capacity of clovers to provide the animal with a more favourable balance of nutrients.


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