Nutritional status and intake regulation in sheep. III. The relationship between improvement of nitrogen status and increase in voluntary intake of low-protein roughages by sheep

1965 ◽  
Vol 16 (3) ◽  
pp. 463 ◽  
Author(s):  
AR Egan
Keyword(s):  
Nitrogen Balance ◽  
Dry Matter ◽  
Alimentary Tract ◽  
Nitrogen Status ◽  
Nutritional Factors ◽  
Low Protein ◽  
Voluntary Intake ◽  
Status Data ◽  
Intake Regulation ◽  
The Relationship

Relationships between the intake of feed by sheep fed on low-protein roughage and the improvement of the sheep's nitrogen status by duodenal supplementation are described. Results of experiments suggest that an increased protein intake initiated an improvement in dry matter and digestible energy intake which was related to improved nitrogen balance. An increased rate of passage of food through the alimentary tract did not alone account for greater intakes, since at a given rate of passage, the intake was higher when the sheep were in higher nitrogen balance; this suggested a higher level of 'fill' of the alimentary tract with improved nitrogen status. Data from other experiments where nitrogen supplements were given in the diet were examined similarly and similar conclusions were reached. The possible roles of protein absorbed by the sheep and of certain other nutritional factors are discussed in relation to possible mechanisms for regulating roughage intake by the sheep.

Nutritional status and intake regulation in sheep. II. The influence of sustained duodenal infusions of casein or urea upon voluntary intake of low-protein roughages by sheep

1965 ◽  
Vol 16 (3) ◽  
pp. 451 ◽  
Author(s):  
AR Egan
Keyword(s):  
Retention Time ◽  
Nitrogen Balance ◽  
Dry Matter ◽  
Alimentary Tract ◽  
Phosphate Solution ◽  
Mean Retention Time ◽  
Cotton Thread ◽  
Low Protein ◽  
Protein Status ◽  
Intake Regulation

In each of two experiments, casein dissolved in 1% disodium hydrogen orthophosphate given daily to sheep per duodenum increased the intake of the roughages offered. Results in each experiment were compared with those of infusions of equivalent volumes of phosphate solution alone. In experiment 1, casein (4.5 g nitrogen/day) infused per duodenum resulted in a 42% increase in intake of a chaffed oaten hay (0.56% nitrogen) diet. Mean retention time of food in the alimentary tract was not altered, but the digestibility of the dry matter and the rate of cotton thread digestion in the rumen were depressed. Urea (4.5 g nitrogen/day) given per duodenum gave a 12% increase in intake, associated with a greater rate of cotton thread digestion in the rumen, and a consistently shorter mean retention time of residues in the alimentary tract. Evidence suggested a greater amount of dry matter in the gut when casein was given but not when urea was given. Nitrogen balance was improved from negative values to positive values by both casein and urea infusions. In experiment 2, a diet of wheaten straw supplemented with 3% urea was offered. Under these conditions, casein (6 g nitrogen/day) improved nitrogen balance and produced an average increase of 11% in daily dry matter intake. Rates of cotton thread digestion, digestibility of dry matter, mean retention time, and number of rumination chews were all unaltered by casein infusion. Results from both experiments are discussed in relation to current hypotheses of the mechanisms for regulating roughage intake in ruminants. A possible role of protein status of the animal in influencing the amount of dry matter which is held in the alimentary tract under ad libitum feeding conditions is suggested.

Nutritional status and intake regulation in sheep. I. Effects of duodenally infused single doses of casein, urea, and propionate upon voluntary intake of a low-protein roughage by sheep

1965 ◽  
Vol 16 (3) ◽  
pp. 437 ◽  
Author(s):  
AR Egan ◽  
RJ Moir
Keyword(s):  
Dry Matter ◽  
Major Effect ◽  
Dry Matter Intake ◽  
Protein Supplement ◽  
Cellulose Digestion ◽  
Low Protein ◽  
Protein Status ◽  
Voluntary Intake ◽  
Intake Regulation ◽  
Low Nitrogen

In each of two experiments, single infusions of casein administered to sheep per duodenum produced substantial and rapid increases in voluntary intake of chaffed oaten hay diets of low nitrogen content (0.62–0.70% nitrogen). The effect commenced within 16 hr of completion of the infusion, and occurred before any observed change in the rate of cellulose digestion in the rumen. When urea was infused per duodenum at the same level of nitrogen as with the casein, an increase in intake occurred on the day following infusion in one experiment. In a second experiment no such response occurred. Faster rates of cellulose digestion were observed on the day of infusion, apparently due to recycling of nitrogen to the rumen. Of the 10 g of nitrogen infused, 7.4 g of casein nitrogen and 5 g of urea nitrogen were retained. Propionate, infused in an attempt to reproduce the gluconeogenic properties of casein, did not have any major effect on daily dry matter intake, although it caused a depression in intake during the period of infusion in one experiment. Results are discussed in relation to the possible mechanism of response to the protein supplement. The possibility is suggested that the protein status of the animal is a component of a chemoregulatory mechanism governing the intake of low nitrogen diets by sheep.

scholarly journals Factors affecting the voluntary intake of food by cows

1966 ◽  
Vol 20 (2) ◽  
pp. 229-244 ◽  
Author(s):  
R. C. Campling ◽  
M. Freer
Keyword(s):  
Dry Matter ◽  
Alimentary Tract ◽  
Crude Fibre ◽  
Factors Affecting ◽  
The Poor ◽  
Food Digestibility ◽  
Oat Straw ◽  
The Mean ◽  
Voluntary Intake ◽  
The Relationship

1. Two experiments were conducted to examine the effect of grinding and pelleting roughages on the voluntary intake of food, digestibility, time of retention of food in the digestive tract, amounts of digesta in the recitulo-rumen and eating and ruminating behaviour of adult, non-lactating, non-pregnant cows. The first experiment was with artificially dried grass and the second with oat straw; also, with a diet of ground, pelleted oat straw the effect was studied of giving a daily intraruminal infusion of 150 g urea. The size of the particles of the ground roughages are given. 2. The mean voluntary intakes of long and ground dried grass were similar, the voluntary intake of ground, pelleted oat straw was 26% greater than that of long straw and the daily infusion of urea increased the voluntary intake of ground, pelleted oat straw by 53%. 3. The digestibility of the ground roughages was lower than that of the long roughages, the lower digestibility of the ground roughages was due mainly to the poor digestibility of crude fibre in the reticulo-rumen. The rate of disappearance of cotton thread placed in the ventral sac of the rumen was slower with ground than with long roughages. 4. The mean times of retention of ground roughages were shorter than those of long roughages when equal and restricted amounts of each food were given; with food offered ad lib. there was little difference between the mean times of retention of long and ground roughages in the alimentary tract. 5. On average, the mean amounts of digesta dry matter in the reticulo-rumen immediately after a meal were about the same with long and ground dried grass, with long and ground oat straw the amounts of dry matter were similar, but when the intraruminal infusion of urea was given the amount of dry matter increased by 49%. 6. The rate of eating (min/kg food) ground, pelleted roughages was much faster than that with long roughages; when the cows received ground roughage rumination did not occur but during short periods triple reticular contractions were seen. 7. The relationship between the voluntary intake of food, the amount of digesta in the reticulo-rumen and the rate of disappearance of digesta from the alimentary tract is discussed.

Prediction of the voluntary intake of grass silages by beef cattle. 1. Linear regression analyses

1990 ◽  
Vol 50 (3) ◽  
pp. 425-438 ◽  
Author(s):  
A. J. Rook ◽  
M. Gill
Keyword(s):  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Live Weight ◽  
Ammonia Nitrogen ◽  
Dry Matter Intake ◽  
Digestible Organic Matter ◽  
Voluntary Intake ◽  
Relationship Of ◽  
The Relationship ◽  
Linear Regressions

ABSTRACTData on individually recorded silage dry-matter intake (SDMI), concentrate dry-matter intake (CDMI) and live weight of steers and data on silage composition including toluene dry matter (TDM), pH, total nitrogen (N), ammonia nitrogen (NH3-N), volatile fatty acids (VFAs), digestible organic matter in the dry matter (DOMD) and neutral-detergent fibre (NDF) obtained from experiments conducted at three sites were used to obtain simple and multiple linear regressions of SDMI on other variables.Live weight accounted for a high proportion of the variation in intake but this effect could generally be removed by scaling intake by live weight raised to the power of 0·75 (M0·75). CDMI was the most important factor affecting scaled intake in mixed diets. TDM, NH,-N and VFAs all had important effects on SDMI. The relationship of SDMI with TDM was curvilinear suggesting that there is little to be gained in intake terms from wilting to TDM above 250 g/kg. The effect of NH3-N appeared to be related more to its correlation with VFAs than with any other nitrogenous constituent while the VFAs appeared to have a direct effect on SDMI. The effects of N and pH on SDMI were generally small. DOMD and NDF had relatively little effect on SDMI. Significant differences in intercepts between sites were found for most relationships although common slopes were often found.

FEED CONSUMPTION AND GROWTH OF DAIRY HEIFER AND BULL CALVES FED CALF STARTERS DIFFERING IN PROTEIN CONTENT

1974 ◽  
Vol 54 (3) ◽  
pp. 315-324 ◽  
Author(s):  
G. M. JONES ◽  
L. P. JACOBS ◽  
L. J. MARTIN
Keyword(s):  
Feed Efficiency ◽  
Crude Protein ◽  
Dry Matter ◽  
High Energy ◽  
Feed Consumption ◽  
High Fat ◽  
Low Protein ◽  
Holstein Bull ◽  
Bull Calves ◽  
Voluntary Intake

Four groups of five Holstein heifer calves were fed calf starter ad libitum from the 5th through the 16th wk. Diets differed in crude protein (CP) content (9.3, 17.8, and 22.2% CP) and were compared to a 21% CP, high-fat milk replacer (HFMR) during 28-day periods. Voluntary intake was not affected by starter CP content. However, increasing dietary CP content increased gains and feed efficiency. Gains were similar between the high-protein starter and the HFMR. When calves in one group received a different starter each day, voluntary consumption of the low-protein starter was reduced. In the second experiment, the HFMR and a starter containing either 10.6, 15.3, or 22.8% CP were fed to Holstein bull calves from wk 2 through 4. The starters were each fed for 21-day periods to each group of calves after weaning from HFMR. A fourth group received a starter of different CP content each day. A fifth group received only HFMR for the entire period. After the 4th wk, calves fed HFMR consumed less dry matter (DM) but gained weight most rapidly. Average daily gains were increased by the medium- and high- over the low-protein calf starter (P < 0.05). Feed efficiency was subsequently reduced by this diet. A ration containing no more than 18% CP was satisfactory for dairy-replacement heifers. However, additional studies should examine the feasibility of marketing 136-kg calves on high-energy calf starters.

EFFECT OF CECECTOMY ON DIGESTIBILITY COEFFICIENTS AND NITROGEN BALANCE IN PONIES

1979 ◽  
Vol 59 (1) ◽  
pp. 145-151 ◽  
Author(s):  
W. S. SAUER ◽  
T. J. DEVLIN ◽  
R. J. PARKER ◽  
N. E. STANGER ◽  
S. C. STOTHERS ◽  
...  
Keyword(s):  
Nitrogen Balance ◽  
Dry Matter ◽  
Chromic Oxide ◽  
Apparent Digestibility ◽  
Acid Detergent Fiber ◽  
Indicator Method ◽  
Low Protein ◽  
Matter Energy

Two balance studies were conducted using intact and cecectomized ponies to compare the utilization of low and high concentrate diets as well as low concentrate diets with and without added urea. In addition, the use of chromic oxide in digestion was evaluated. Apparent digestibility coefficients for dry matter, energy, protein, crude and acid-detergent fiber were consistently lower when the indicator method as opposed to the total collection procedure was employed. With the exception of fat, for which digestibility increased, the digestilities of dry matter, energy, protein, crude and acid-detergent fiber decreased following removal of the cecum. Cecectomy had no effect on nitrogen balance. There were no interactions between the effects of surgery and those of diets. This shows that there was no apparent advantage resulting from cecal fermentation in the utilization of the low concentrate diet. Addition of urea to a low protein, low concentrate diet tended to improve nitrogen balance regardless of cecectomy.

Nutritive evaluation of two strains of mature subterranean clover

1968 ◽  
Vol 8 (32) ◽  
pp. 295 ◽  
Author(s):  
ID Hume ◽  
M Somers ◽  
NR McKeown
Keyword(s):  
Dry Matter ◽  
Nutritive Value ◽  
Biological Significance ◽  
Subterranean Clover ◽  
In Vitro Digestibility ◽  
Voluntary Intake ◽  
Main Component ◽  
The Relationship

The relationship between the in vivo and in vitro digestibility of leguminous herbage was examined. Further studies were made using in vivo-in vitro digestibility estimations to compare the nutritive value to sheep of two strains (Yarloop and Woogenellup) of subterranean clover. The digestibilities of the main component parts (viz. stem, petiole, leaf, and burr) of the plants of each strain were also estimated in vitro. Digestibility differences between strains and between parts were examined on the basis of the chemical composition of their dry matter. Woogenellup was significantly more digestible than Yarloop, both in vivo and in vitro. Voluntary intake of Woogenellup was also significantly greater than that of Yarloop. The in vitro digestibility of stem did not differ significantly from that of petiole. Nor did the digestibility of leaf differ significantly from that of burr. However, the digestibility of stem and petiole together was greater than that of leaf and burr together. These findings are discussed in relation to their possible biological significance.

The relationship between voluntary intake and mean apparent retention time in the rumen

1972 ◽  
Vol 23 (5) ◽  
pp. 871 ◽  
Author(s):  
RF Thornton ◽  
DJ Minson
Keyword(s):  
Retention Time ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Two Factors ◽  
Voluntary Intake ◽  
The Relationship

The relationship between mean apparent retention time of dry matter in the reticulorumen (RD, hr) and the daily voluntary dry matter intake (ID, g/day) of six dried panicum diets was determined on sheep which were offered fresh feed every hour. RD was measured by emptying the reticulorumen via a large rumen fistula. ID for the six diets by the sheep with fistulae was slightly higher than, and correlated (r = 0.99, P < 0.001) with, that previously found when the same diets were offered to intact sheep. ID varied from 659 to 1355 g/day and RD from 13.3 to 27.1 hr. These two factors were inversely related:

The voluntary intake and utilization of roughage–concentrate diets by sheep. 2. Barley and soya bean meal supplementation of hay diets

1971 ◽  
Vol 13 (1) ◽  
pp. 83-92 ◽  
Author(s):  
J. R. Crabtree ◽  
G. L. Williams
Keyword(s):  
Dry Matter ◽  
Live Weight ◽  
Soya Bean ◽  
Metabolizable Energy ◽  
Ewe Lambs ◽  
Bean Meal ◽  
Voluntary Intake ◽  
Metabolizable Energy Intake ◽  
Soya Bean Meal ◽  
The Relationship

SUMMARYThree levels of soya bean meal (0%, 25% and 50% of the intake of hay dry matter) combined with three levels of pelleted barley (0%, 50% and 100% of the intake of hay dry matter) in a factorial arrangement of treatments were offered to Welsh Mountain ewe lambs receiving hay ad libitum for 14 weeks.When barley was not given, soya bean meal added at 25% of the hay intake increased hay voluntary intake from 287 g/day to 412 g/day but hay intake was depressed to 339 g/day by a further increase in the level of soya bean meal. When barley was given, soya bean meal did not affect hay intake. With one exception, an increase in barley reduced hay intake, with the result that there were no differences between treatments in the digestible energy intakes of lambs receiving barley at each level of soya bean meal. In general, it was found that an increase in the concentrate allowance (barley + soya bean) reduced hay intake, whereas an increase in the crude protein content of the concentrate increased hay intake. The relationship between live-weight change, metabolizable energy intake and live weight was examined by regression analysis. Although live weight and voluntary intake were unrelated at the start of the experiment, a positive relationship emerged as the experiment progressed.

scholarly journals The origin of urinary aromatic compounds excreted by ruminants

1983 ◽  
Vol 49 (1) ◽  
pp. 87-99 ◽  
Author(s):  
A. K. Martin ◽  
J. A. Milne ◽  
P. Moberly
Keyword(s):  
Dry Matter ◽  
Phenylacetic Acid ◽  
Acid Output ◽  
Calluna Vulgaris ◽  
Aromatic Acids ◽  
Rumen Degradation ◽  
Linear Relationships ◽  
Order Of Magnitude ◽  
Voluntary Intake ◽  
The Relationship

1. Studies were made of the extent to which p-cresol, catechol, quinol and orcinol infused through rumen or abomasal cannulas to sheep were recovered in their urine.2. Rumen fermentation of dietary phenolic compounds caused the excretion of simple phenols in the urine. In decreasing order of magnitude these were: p-cresol, catechol, phenol and 4-methylcatechol with only traces of quinol and orcinol.3. The percentages of rumen-infused p-cresol or orcinol recovered as increments in the urinary phenol outputs of sheep (94 and 99% respectively) following infusion showed that rumen degradation of these phenols was negligible.4. After rumen infusion of catechol and quinol, mean recoveries of these phenols in urine were only 55 and 77% respectively. Possible reasons for these incomplete recoveries are discussed.5. Studies were also made of the use of the urinary phenol output of phenols characteristic of particular forages as indices of their voluntary intake by sheep. Calluna vulgaris L. (Hull) (heather) may contain 1300–3600 mg/kg dry matter (DM) of orcinol and 200–800 mg/kg DM of quinol as β-glycosides. When heather was offered ad lib. to sheep given one of five levels of grass, linear relationships were found between heather intake and urinary quinol and orcinol outputs.6. The urinary output of aromatic acids was also determined when sheep ate grass and heather. Urinary phenylacetic acid output was linearly related to grass but not to heather intake. The relationship between urinary phenylacetic acid output and grass intake could vary with different forages but that between orcinol output and heather intake was considered a useful index of heather intake.7. Methods for the assay of urine phenols are discussed.

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