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:

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.

The possibility of predicting the sheep voluntary dry matter intake of hays from their rumen degradation characteristics

1989 ◽  
Vol 1989 ◽  
pp. 71-71
Author(s):  
S. Lopez ◽  
Dolores Carro ◽  
J.S. Gonzalez ◽  
F.J. Ovejero
Keyword(s):  
Cell Walls ◽  
Dry Matter ◽  
Red Clover ◽  
Dry Matter Intake ◽  
Rumen Degradation ◽  
Mixed Grass ◽  
Voluntary Intake ◽  
Grass Sward ◽  
The Relationship

Ability to predict accurately the intake of digestible nutrients by ruminants is of great interest. The feed intake can be limited mainly by the amount of undigested residue remaining in the rumen. Ingested feed disappears from the rumen in two ways: through digestion and through passage. So, forages with easily degraded cell-walls, may promote faster rates of digestion and passage and allow the animal to consume more feed (Hovell et al., 1986).The objective of the present study is to determine the rate and extent of rumen degradation of various hays “in situ” and to evaluate the ability to predict the voluntary intake from these rumen degradation characteristics.Eleven sun-cured hays from three cultivars (alfalfa, red-clover and vetch-cereal), two sown grasslands (grass-clover mixture and mixed grass sward) and six permanent meadows were used to study the relationship between some rumen degradation characteristics and the voluntary dry matter intake (VDMI) by 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

The relationship between protein nutrition, reproductive effort and breakdown in immunity toTeladorsagia circumcinctain periparturient ewes

2001 ◽  
Vol 72 (3) ◽  
pp. 595-606 ◽  
Author(s):  
J.G. M. Houdijk ◽  
I. Kyriazakis ◽  
F. Jackson ◽  
R. L. Coop
Keyword(s):  
Host Resistance ◽  
Dry Matter ◽  
Reproductive Effort ◽  
Late Pregnancy ◽  
Gastrointestinal Nematodes ◽  
Dry Matter Intake ◽  
Teladorsagia Circumcincta ◽  
Nutrient Partitioning ◽  
Ad Libitum ◽  
The Relationship

AbstractA nutritional hypothesis for the occurrence of the periparturient relaxation of immunity (PPRI) to gastrointestinal nematodes was tested within the bounds of a nutrient partitioning framework. It was hypothesized that at times of a scarce supply of metabolizable protein (MP), an increase in MP supply or a reduction in MP demand (having singles instead of twins) should lower the extent of PPRI in sheep. Twenty-one single- and 21 twin-bearing and -rearing Finn-Dorset ewes, 2 to 7 years old, and repeatedly infected withTeladorsagia circumcincta, were given one of three pelleted foods (no. = 7). The foods were formulated to supply 0·8 (L), 1·0 (M) and 1·2 (H) times the MP requirements during lactation, and were offeredad libitumfrom d–21to d35(d0 is day of parturition). Faecal egg counts (FEC) were assessed twice weekly as an indicator for host resistance. Dry-matter intake (DMI) during late pregnancy was higher than expected, and MP supply did not limit performance at this stage. In accordance with the hypothesis, there were no indications of a breakdown of immunity toT. circumcinctaduring late pregnancy. DMI during lactation did not differ between the single- and twin-rearing ewes. Calculated milk production was lower for the L than for the M and H ewes, especially for the twin-rearing ewes. A temporarily elevated FEC was observed during the first few days in lactation, which was probably mainly due to changes in faecal output rather than to PPRI. The FEC returned to low, late pregnancy levels at d12and remained low for the single- but not for the twin-rearing ewes (P< 0·001). Overall, the L ewes had higher FEC than the M and H ewes from d19onwards; this effect was more pronounced for the twin- than for the single-rearing ewes. It was postulated that DMI achieved overcame MP scarcity and thus prevented breakdown in immunity in the single-rearing ewes. The data support the view that, at times of MP scarcity, an increase in MP supply and reduction in MP demand can lower the extent of the breakdown in immunity towardsT. circumcincta.

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.

The relationship between apparent retention time in the rumen, voluntary intake, and apparent digestibility of legume and grass diets in sheep

1973 ◽  
Vol 24 (6) ◽  
pp. 889 ◽  
Author(s):  
RF Thornton ◽  
DJ Minson
Keyword(s):  
Organic Matter ◽  
Retention Time ◽  
Daily Intake ◽  
Organic Matter Content ◽  
Matter Content ◽  
Apparent Digestibility ◽  
Jaw Movements ◽  
Digestible Organic Matter ◽  
Voluntary Intake ◽  
The Relationship

Eight grasses and six legumes were fed ad libitum at hourly intervals to wethers fitted with large rumen fistulas to determine voluntary intake, apparent digestibility, and the apparent retention time of organic matter in the rumen, as well as the quantity of rumen digesta and the organic matter content of the rumen digesta. The voluntary intake of legumes was 28% higher than that of equally digestible grasses. This difference was caused by a shorter retention time (17%) and a higher amount of organic matter (14%) in the rumen digesta from legume diets than from grass diets. The weight of wet digesta in the rumen of sheep fed on legumes was 7% lower than from those fed on grass. Neither the quantity of digesta nor the quantity of organic matter in the rumen was related to the voluntary intake, digestibility, or retention time of organic matter in the rumen. Number of jaw movements each day and rate of cotton thread digestion were not related to the retention time of the diets either. Daily intake of digestible organic matter (DOMI, g/day) was closely correlated with retention time (RTOM, hr) for the feeds in this study (r = –0.93) and the same relation applied to both temperate and tropical feeds, viz. DOMI = 1276–50.7 RTOM (r=0.96) Differences in voluntary intake between grasses and legumes were attributed to differences in retention time and the density to which the food was packed in the rumen.

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

scholarly journals The voluntary intake and digestibility, in sheep, of chopped and pelleted Digitaria decumbens (pangola grass) following a late application of fertilizer nitrogen

1967 ◽  
Vol 21 (3) ◽  
pp. 587-597 ◽  
Author(s):  
D. J. Minson
Keyword(s):  
Organic Matter ◽  
Protein Content ◽  
Retention Time ◽  
Crude Protein ◽  
Dry Matter ◽  
Nitrogen Retention ◽  
Fertilizer Nitrogen ◽  
Food Digestibility ◽  
Voluntary Intake ◽  
Chopped Grass

1. Experiments were conducted with wether sheep in 1964 and 1965 fed pelleted or chopped mature Digitaria decubemes Stent (pangola grass) bay containing different crude protein contents. The voluntary intake of food, digestibility of dry matter and nitrogen, nitrogen retention and apparent time of retention of feed organic matter in the reticulo-rumen were measured. The different crude protein contents of the grass were obtained by applications of urea to the sward 14 and 28 days before cutting for hay in 1964 and 1965 respectively. This treatment increased the crude protein content of the dry matter from 4.9% to 8.7% in 1964 and from 3.7% to 7.2% in 1965. The size of the particles of the ground hay before pelleting is given.2. The mean voluntary intake of chopped fertilized grass was 10% and 54% greater than that of the unfertilized; the voluntary intake of pellets made from fertilized grass was 35% and 75% greater than of those made from the unfertilized grass in 1964 and 1965 respectively.3. The voluntary intake of pellets of unfertilized grass was 7% and 14% greater than that 30% greater than that of chopped fertilized grass in 1964 and 1965 respectively.4. The digestibility of the pellets was less than that of the chopped grass.5. The apparent digestibility of the feed nitrogen was increased by the fertilizer nitrogen, but grinding and pelleting had no consistent effect. Sheep eating chopped or pelleted fertilized hay were in positive nitrogen balance.6. The apparent retention time of organic matter in the reticulo-rumen was longer when the sheep were eating chopped hay than when they were eating pellets. In 1964 the apparent retention time of organic matter in the reticulo-rumen was shorter for chopped and pelleted unfertilized grass than for chopped and pelleted fertilized grass, but in 1965 the order was reversed.7. The relationship between voluntary intake, apparent retention time of organic matter in the rumen and the protein content of the food is discussed.

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