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.

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.

Voluntary intake of low protein diets by sheep

1963 ◽  
Vol 5 (3) ◽  
pp. 269-276 ◽  
Author(s):  
R. C. Elliott ◽  
J. H. Topps
Keyword(s):  
Slow Rate ◽  
Crude Protein ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Apparent Digestibility ◽  
Crude Protein Content ◽  
N Content ◽  
Low Protein ◽  
Voluntary Intake ◽  
Protein Diets

SUMMARY1. Sixteen foods, ranging in crude protein content from approximately 2·6 to 10·0%, were each offered ad lib. to four wether sheep. Dry-matter intake, N content and apparent digestibility of dry matter for each food were determined.2. Voluntary intake of food dry matter was closely related to N content.3. Slow fermentation in the reticulo-rumen and the associated slow rate of passage through the digestive tract may control the intake of low protein foods by sheep.4. There was evidence of adaptation of sheep to low protein diets as the trials progressed and significant differences occurred in voluntary food consumption between sheep.

EVALUATION OF TIMOTHY CULTIVARS FOR VOLUNTARY INTAKE AND NUTRIENT COMPONENTS

1988 ◽  
Vol 68 (4) ◽  
pp. 1121-1129 ◽  
Author(s):  
W. N. MASON ◽  
P. M. FLIPOT
Keyword(s):  
Key Words ◽  
Dry Matter ◽  
Phleum Pratense ◽  
Dry Matter Intake ◽  
Dry Matter Yield ◽  
Dry Matter Digestibility ◽  
Flower Stage ◽  
Voluntary Intake ◽  
Phleum Pratense L

Five timothy (Phleum pratense L.) cultivars, Clair, Champ, Milton, Climax and Bounty, were harvested at first flower stage during 2 consecutive years and in the regrowth for 1 yr. The forages were each offered as hay to 15 young rams to evaluate voluntary intake. Five animals were used to determine initial harvest dry matter digestibility. The cultivars varied significantly in voluntary intake at first flower stage. The highest intake (g kg−0.75 d−1) averaged for the years was obtained in the early cultivar Champ (65.9), which was 10% more than that of the medium-late cultivar Climax. The cultivars did not differ significantly in dry matter digestibility. In the regrowth, the relative intakes of the cultivars were essentially reversed from that of the initial harvest. The voluntary intake was substantially higher but the differences among forages were less marked. Climax regrowth voluntary intake was higher (P < 0.05) than all cultivars, except Bounty. A 15% range in digestible dry matter intake was present among cultivars. The ranking of the culivars for digestible dry matter was different than for dry matter yield. Key words: Timothy, Phleum pratense L., voluntary intake, dry matter digestibility

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.

Effect of reproductive state and concentrate supplementation on liquid and particulate turnover in the rumen of ewes given ammonia treated straw

1995 ◽  
Vol 46 (8) ◽  
pp. 1579 ◽  
Author(s):  
JF Perez ◽  
J Gasa ◽  
C Castrillo ◽  
JA Guada
Keyword(s):  
Dry Matter ◽  
Late Pregnancy ◽  
Dry Matter Intake ◽  
Barley Straw ◽  
Energy Status ◽  
Reproductive State ◽  
Concentrate Supplementation ◽  
Ad Libitum ◽  
Voluntary Intake ◽  
Breeding Status

Rates of passage of liquid and particulate markers (Co-EDTA, Cr mordanted fibres and Yb) were measured in ewes at late pregnancy, lactation and non-breeding status. Animals were given ammonia treated barley straw ad libitum supplemented daily with 250 and 550 (pregnancy), 550 and 850 (lactation) and 250, 550 and 850 (non-breeding) g of concentrate. The effect of the reproductive state was analysed only on ewes fed on 550 g of concentrate. Lactating ewes showed a higher voluntary straw intake (970 g/day) than pregnant or non-breeding ewes (720 and 790 g/day respectively), but there were not significant differences in the OM digestibility (OMD) among reproductive states. Increasing concentrate supplementation promoted significant decreases in the voluntary intake of straw, associated with an enhanced OMD ( P < 0.05). Fractional outflow rates (FOR/h) were higher in pregnant and non-breeding than in lactating ewes, although differences were only significant ( P < 0.01) for Chromium derived values. Ewes given 250 g of concentrate showed lower ( P < 0.05) FOR than those given 550 and 850 g/day. Results support the idea that in ruminants fed on low quality roughages, voluntary dry matter intake is mainly restricted by rumen capacity, although the energy status of the animals might influence the extent of this restriction.

VOLUNTARY INTAKE OF SHREDDED NEWSPRINT BY DAIRY COWS

1982 ◽  
Vol 62 (3) ◽  
pp. 799-806 ◽  
Author(s):  
D. G. GRIEVE ◽  
J. H. BURTON ◽  
H. E. BRAUN ◽  
R. FRANK
Keyword(s):  
Heavy Metals ◽  
Milk Fat ◽  
Dry Matter ◽  
Latin Square ◽  
Corn Silage ◽  
Dry Matter Intake ◽  
Feeding Time ◽  
High Moisture ◽  
Lactating Cows ◽  
Voluntary Intake

Shredded newsprint is a potential source of bedding for livestock, but because it may contain certain heavy metals and polychlorinated biphenyls significant voluntary consumption of newsprint by animals would be undesirable. To determine consumption levels, 18 Holstein cows in mid-lactation (average 19 wk) were used in a double latin square design. Squares represented access to shredded newsprint or chopped hay in the feed manger except during feeding time. Within squares, cows were allotted to each of three complete mixed rations over three 6-wk treatment periods. Rations comprised hay crop silage, corn silage, high moisture grain corn and soybean meal with roughage:concentrate ratios of 30:70 (LR), 50:50 (MR) and 70:30 (HR). Mixed rations were fed according to individual cow requirements for energy depending on body weight, milk yield and milk fat percent. Cows were allowed 4 h after each of two feedings per day to consume their allotted mixed ration. Voluntary consumption of newsprint was only 0.3 kg per cow per day or 2% of total dry matter intake while for those offered hay consumption was 2.6 kg∙cow−1∙day−1 or 15% of total dry matter intake. Intakes of mixed rations were unaffected by roughage:concentrate ratio or newsprint versus hay. However, total dry matter consumption (mixed ration plus newsprint or hay) was higher for cows offered hay (17.3 kg∙cow−1∙day−1) than for those offered newsprint (15.1 kg∙cow−1∙day−1). Levels of heavy metals in milk or blood samples of cows with access to newsprint were within normally accepted ranges. PCBs were at undetectable levels in all cases. Bedding cows with newsprint is unlikely to result in significant consumption or contamination of animals or their products. Key words: Lactating cows, newsprint consumption, heavy metals

Utilization of oaten hay by cattle: effects of milling and urea supplementation

1983 ◽  
Vol 23 (120) ◽  
pp. 14 ◽  
Author(s):  
NG Yates ◽  
RJ Moir
Keyword(s):  
Retention Time ◽  
Dry Matter ◽  
Latin Square ◽  
Ammonia Concentration ◽  
Dry Matter Intake ◽  
Cellulose Digestion ◽  
Mean Retention Time ◽  
Dry Matter Digestibility ◽  
Rumen Ph ◽  
Cellulose Digestibility

Oaten hay in either long or milled form, with or without a continuous intra-ruminal infusion of urea at the rate of 160 g/d, was offered ad libitum to four rumen fistulated steers in a 4 x 4 Latin square design experiment. Milling increased dry matter intake from 49.2 to 65.4 g/kg LW0 75.d (P< 0.001) and decreased mean retention time from 66.7 to 54.2 h (P< 0.001). Rates of cellulose digestion and dry matter digestibilities were similar for long and milled hay. Urea increased dry matter intake (from 49.0 to 65.6 g/kg LW0 75.d; P< 0.001), dry matter digestibility (from 58.1 to 65.3%; P< 0.01) cellulose digestibility (from 48.5 to 63.1%; P< 0.01) and the rate of cellulose digestion (P< 0.001), and decreased mean retention time from 65.3 to 55.6 h ( P < 0.01). Digestible dry matter intakes increased 29% with milling and 52% with urea and the effects were additive. Urea increased digestible cellulose intake to a greater extent with milled hay (91 %) than with long hay (64%). Digestible dry matter intake was closely related to liveweight change. When urea was given liveweight gain was higher for milled hay than for long hay (0.69 vs 0.11 kg/head.d) and without urea liveweight loss was less for milled hay than for long hay (-0.07 vs -0.45 kg/head.d). Nitrogen digestibility and balance were significantly higher when urea was given. Total volatile fatty acid concentrations were significantly higher and rumen pH significantly lower with urea compared with no urea and with milled hay compared with long hay. Urea increased rumen-ammonia concentration from 1.65 to 19.68 mg1100 ml (P< 0.001) and total free bacterial concentration (P < 0.05). The results demonstrate significant and additive benefits from the administration of urea to hay containing 0.8% nitrogen and from milling through a screen size of 7.6 mm.

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.

Finishing Performance of Hill Lambs Fed Clover-Rich Baled Silage to Ukrofs Standards

1994 ◽  
Vol 1994 ◽  
pp. 130-130
Author(s):  
R Keatinge ◽  
W A Murray
Keyword(s):  
United Kingdom ◽  
Dry Matter ◽  
Organic Food ◽  
Organic Production ◽  
Dry Matter Intake ◽  
Concentrate Supplementation ◽  
Grass Silage ◽  
The United Kingdom ◽  
Food Standards ◽  
Low Nitrogen

Within conventional silage finishing systems, forage quality is critical to lamb performance and some concentrate feeding is generally required (Fitzgerald, 1987). Rate of finish may also be manipulated by increasing the concentrate component of the diet, particularly in the latter stages of the finishing period. For organic production however, the United Kingdom Register of Organic Food Standards (UKROFS) limit concentrate supplementation to 40% of daily dry matter intake, and a flatter pattern of concentrate allocation is generally required. Where diets containing a high proportion of clover (more likely under an organic or low nitrogen system) are fed, improvements in lamb performance have been shown in grazing animals (Clark, 1988) and following ensiling (Vipond et al, 1992). The aim of this experiment was to assess the potential of high clover silage to finish hill lambs from the organic unit at ADAS Redesdale.One hundred and forty four approximately six month old Scottish Blackface wether lambs (mean liveweight 30.0 kg, se = 0.24) were housed off silage aftermath and assigned (in pens of twelve) to one of three treatments - grass silage plus 400 g concentrate (GH), high clover silage plus 400 g concentrate (CH) or high clover silage plus 200 g of mineralised barley (CL).

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