PREDICTION OF DIGESTIBLE ENERGY INTAKE BY SHEEP OF DIETS CONTAINING GROUND ROUGHAGE AND GRAIN

1977 ◽  
Vol 57 (2) ◽  
pp. 279-288 ◽  
Author(s):  
S. O. THORLACIUS

Digestibility and intake of diets containing 8, 28, 48 or 68% ground wheat straw plus ground crested wheatgrass and rapeseed meal, and diets containing 33, 48, 63 and 78% ground crested wheatgrass plus barley and rapeseed meal was measured with four yearling wethers per diet. Digestible energy (DE) content ranged from 2.07 to 2.95 kcal/g dry matter (DM) and dry matter digestibility (DMD) (%) from 48.7 to 71.1%. Regression of DE intake y (kcal/w0.75kg/d) on DE content (x) was curvilinear; y = −2,133 + 1,626x − 277.9x2, r = 0.996, P < 0.01, SE = ± 7.3. There was also a curvilinear relationship between diet density, as fed, (x) g (DM)/ml and DMD (%), y = 9.057 + 364.1x − 530.0x2, r = 0.970, P < 0.01, SE = ± 2.4. A linear regression equation was calculated over the DE range (2.07–2.52) for which there was an obvious increase in DE intake with increasing diet DE content; y = −700.6 + 361x, r = 0.994, P < 0.01, SE = ± 9.4, y = DE intake (kcal/w0.75kg/d), x = DE [kcal/g (DM)]. Using this regression equation and assuming a linear increase in DE intake with increase in diet DE content up to a point at which the apparent energy demand of the animal is satisfied gave a more accurate prediction of DE intake than when the curvilinear regression equation, y = −2,133 + 1,626x − 277.9x2, was used empirically. Accuracy of the prediction was further improved by expressing DE/unit ration volume instead of per unit DM. The sheep used in the present experiments had an apparent energy demand of 230 kcal/w0.75kg/day which was met at diet DE contents above 0.48 kcal/ml or 2.6 kcal/g (DM). There was a high correlation between in vivo DE content of the diet, y [kcal/g (DM)] and in vitro (x) digestible organic matter content, x, (%), r = 0.991, P < 0.01, y = 0.38 + 0.037x, SE = ± 0.04.

1978 ◽  
Vol 58 (2) ◽  
pp. 167-176 ◽  
Author(s):  
S. O. THORLACIUS ◽  
W. COATES ◽  
M. FELDMAN

In 1972, crested wheatgrass, intermediate wheatgrass, and bromegrass hay were harvested with a Hesston 30 stacking wagon, McKee 1000 stacking wagon, and conventional baler. Crested wheatgrass was stacked at 35 and 29% moisture, intermediate wheatgrass at 38 and 27% moisture, and bromegrass at 41 and 31% moisture. Crested wheatgrass was baled at 23 and 19%, intermediate wheatgrass at 27 and 22%, and bromegrass at 30 and 20% moisture. In 1973, the same grass species were harvested at two moisture levels, 20 and 12% for crested wheatgrass, 25 and 19% for intermediate wheatgrass, and 24 and 20% for bromegrass with a Hesston 10 stacking wagon, Vermeer 605 round baler, and conventional baler. Dry matter intake by lambs and digestibility measurements (in vivo 1972, in vitro 1973) indicated that with the exception of bromegrass harvested in 1972, harvesting machine had little effect on hay quality. In 1972, bromegrass harvested with the stacking wagons was inferior in quality to the baled hay. The effect of moisture level at harvest was dependent on species of grass, harvesting machine, and weather conditions during harvest.


1982 ◽  
Vol 62 (2) ◽  
pp. 391-397
Author(s):  
P. NARASIMHALU ◽  
K. A. WINTER ◽  
H. T. KUNELIUS

Voluntary intakes and apparent digestibilities of wilted grass silages produced under humid climatic conditions of the Maritime Provinces of Canada were determined from feeding trials with wether lambs during two 24-day periods. The silages included seeding year Italian ryegrass (Lolium multiflorum Lam. ’Lemtal’), and first-cut perennial ryegrass (L. perenne L. ’Norlea’), meadow fescue (Festuca pratensis Huds. ’Trader’), orchardgrass (Dactylis glomerata L. ’Tardus’), and quack-grass (Agropyron repens (L.) Beauv.). Second-cut quackgrass was also included. Dry matter and digestibile energy intakes were not different among the first-cut silages (58.8–65.7 g and 746–848 KJ/kg.75BW, respectively) but were higher (P < 0.05) in comparison to the intakes of the nutrients contained in the second-cut quackgrass silage (49.6 g and 467 KJ/kg.75BW). The two-stage in vitro dry matter disappearance, but not the acid-pepsin solubility determinations on the silage samples dried at 55 °C, were closely correlated with the intakes of silage dry matter (r = 0.90, P < 0.05) and digestible energy (r = 0.98, P < 0.01), and with the apparent digestibilities of these respective nutrients (r = 0.92 and 0.96, P < 0.01). Silage content of acid detergent fiber, in comparison with in vitro dry matter disappearance, was less closely correlated with the apparent digestibilities of dry matter (r = −0.82, P < 0.05) and digestible energy (r = -0.75, P < 0.10).


1970 ◽  
Vol 50 (3) ◽  
pp. 557-562 ◽  
Author(s):  
J. E. TROELSEN

Forage of six pure species was harvested for hay at several maturity stages during four years. The digestible energy content of 102 different lots of hay was determined by feeding to four groups of sheep during the same period, and by in vitro digestions and energy analysis of the undigested residues. The relationship between digestible energy content assayed by the two methods was highly significant (r = 0.85) and did not differ between years and species. Exclusion from regression of the hays containing less than 2 or more than 3 digestible kcal/g revealed that the in vitro assay could reproduce the in vivo digestible energy value with a standard deviation of 0.31 in over 70% of the hays. This represented the maturity and quality range of forage commonly fed to cattle and sheep. The in vitro assay therefore appeared promising for commercial quality determinations.


1975 ◽  
Vol 23 (1) ◽  
pp. 3-9
Author(s):  
S. Tamminga ◽  
C.J. van der Koelen

1. Grass from the same sward was ensiled without additive, with 14.6 g formic acid/100 g crude protein or 10.8 g formic acid and 10.6 g formaldehyde/100 g crude protein. Similar grass was dried and pelleted. Drying or ensiling with the mixture reduced solubility of N in the preserved grass but formic acid increased it, and ensiling without additive increased it even more. Apparent digestibility of N in the rumen of cows tended to decrease with decrease in solubility. Digestibility in vitro of the mixed diet given to the cows, calculated from digestibility of the separate components, agreed well with the values in vivo for diets with silages, but was high for that with dried grass. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1972 ◽  
Vol 23 (1) ◽  
pp. 25 ◽  
Author(s):  
DC Brown ◽  
JC Radcliffe

Twenty experimental silages were made from seven pasture species at different stages of maturity. In vivo dry matter, organic matter, and energy ad libitum intakes and digestibilities of the silages were determined with standardized pairs of Merino wethers. The following chemical characteristics of the silages were measured: nitrogen, ammonia nitrogen, total titratable acids, acetic, propionic, butyric, and lactic acids, total volatiles lost during oven drying, lactic acid as a percentage of the total organic acids, pH, acid pepsin dry matter disappearance, dry matter content, and in vitro digestibility and rate of digestion. When all 20 silages were considered, energy intakes on a body weight basis were significantly related to silage pH (r = 0.55) and rate of in vitro digestion (r = 0.58). When the five legume silages were removed from the analysis and only the 15 grass-dominant silages were considered, dry matter intakes were significantly related to acetic (r = –0.57) and propionic acid (r = –0.55) concentrations. Multiple regression analyses did not significantly increase the accuracy of predicting intake. The results suggested that silage intake was negatively related to the degree of fermentation that occurred during the ensiling process.


1997 ◽  
Vol 1997 ◽  
pp. 197-197
Author(s):  
R. Sanderson ◽  
S.J. Lister ◽  
A. Sargeant ◽  
M.S. Dhanoa

The objectives of this study were a) to examine the effect of particle size and silage dry matter (DM) content on the rate and pattern of fermentation of fresh silages in vitro as an aid to modelling the in vivo situation and b) to compare the rate and pattern of fermentation of fresh silage samples with those obtained for freeze-dried material.


1995 ◽  
Vol 1995 ◽  
pp. 113-113
Author(s):  
D M Harris ◽  
A Barlet ◽  
A T Chamberlain

The pressure transducer technique has been proposed as a method of evaluating feed degradation characteristics (Theodorou, 1993) and it has been shown to predict the in vivo and in sacco degradability of forages (Blummel and Orskov, 1993). However the original technique requires rumen liquor and hence access to surgically prepared animals. Faecal material is generally easier to obtain and this work assessed it's suitability as an alternative source of microbes.Rumen liquor (R) and faeces (F) were collected simultaneously from a rumenally fistulated lactating dairy cow. R was mixed 1:1 with modified van Soest medium and F 1:2 to obtain similar dry matter contents. Homogenised strained 20 ml aliquats were inoculated into vented 250 ml bottles containing 180 ml of modified van Soest medium and 1.5g DM of a 7:3 mixture of milled air dried grass silage and 180 g CP / kg DM concentrates. The 7:3 ratio of silage and concentrates was chosen to reflect the diet the donor cow was consuming.


1987 ◽  
Vol 252 (5) ◽  
pp. H906-H915 ◽  
Author(s):  
T. E. Gayeski ◽  
R. J. Connett ◽  
C. R. Honig

Probability distributions of myoglobin (Mb) saturation and intracellular PO2 were determined with subcellular spatial resolution in dog gracilis muscles during steady-state twitch contraction at 5-100% of maximal rate of O2 consumption (VO2). Calculations (Clark, A., and P. A.A. Clark. Biophys. J. 48: 931-938, 1985) and measurements (Gayeski, T. E. J., and C. R. Honig. Adv. Exp. Med. Biol. 200: 487-494, 1986) indicate that the PO2 in equilibrium with Mb is virtually identical to the PO2 at cytochrome aa3. Median intracellular PO2 and PO2 in the lower tails of probability distributions were poorly correlated with VO2. The variability of cell PO2 was greatly diminished when median PO2 was less than the PO2 for half saturation of MB, since Mb acts as a PO2 buffer. The lower tails of PO2 distributions contained almost no anoxic loci even when median PO2 was less than 1 Torr. VO2 was well correlated with the concentration ratio of phosphocreatine to free creatine (PCr/Crf) over a wide range of PO2. PO2 greater than or equal to 0.5 Torr supported maximal VO2 and energy demand. We conclude that 1) the mechanism of action of cytochrome aa3 is the same in red muscle in vivo as in mitochondria in vitro, and 2) an upper bound on the apparent Michaelis constant for maximal VO2 of red muscle is approximately 0.06 Torr.


2020 ◽  
Vol 158 (1-2) ◽  
pp. 150-158 ◽  
Author(s):  
B. C. Silva ◽  
M. V. C. Pacheco ◽  
L. A. Godoi ◽  
F. A. S. Silva ◽  
D. Zanetti ◽  
...  

AbstractAn experiment was conducted to evaluate: (1) the effects of ensiling maize or sorghum grains after reconstitution on readily soluble fraction (a), potentially degradable fraction in the rumen (b) and rate constant for degradation of b (c) of dry matter (DM), organic matter (OM) and starch (STA); and (2) an appropriate incubation time for in situ or in vitro procedures to estimate in vivo digestibility. Four rumen-cannulated Nellore bulls (body weight = 262 ± 19.6 kg) distributed in a 4 × 4 Latin square were used. Diets were based on dry ground maize (DGM); or dry ground sorghum (DGS); or reconstituted ground maize silage; or reconstituted ground sorghum silage. In vitro and in situ incubations of the individual grains and diets were simultaneously performed with in vivo digestibility. In general, reconstituted grains and diets based on reconstituted grains presented greater (P < 0.05) fraction a and lower (P < 0.05) fraction b of DM, OM and STA compared to dry grains and diets based on dry grain. However, the magnitude of response of the reconstitution and ensiling process on DM and OM degradability parameter was greater for maize than that for sorghum. Moreover, no differences (P > 0.05) were observed between DGM- and DGS-based diets for c estimates. The results suggest that the reconstitution process promotes grains protein matrix breakdown increasing STA availability. The incubation times required for in vivo digestibility estimations of DM, OM and STA are 24 h for in situ and 36 h for in vitro procedures.


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