scholarly journals The nutritive value of silages Digestion of organic matter, gross energy and carbohydrate constituents in the rumen and intestines of sheep receiving diets of grass silage or grass silage and barley

1980 ◽  
Vol 43 (3) ◽  
pp. 481-489 ◽  
Author(s):  
P. C. Thomas ◽  
N. C. Kelly ◽  
D. G. Chamberlain ◽  
M. K. Wait

Two experiments were conducted to study the digestion of organic matter, gross energy and carbohydrate constituents in the rumen, small intestine and caecum and colon of sheep given grass silage diets. Three silages made from perennial ryegrass (Lolium perenne) with formic acid as an additive were used. One was made from first-harvest grass in the spring and the others from regrowth grass cut from a single sward in either early autumn or late autumn. Expt I involved a comparison between the spring silage given alone or supplemented with barley (silage:barley, 4:I dry matter (DM) basis). Expt 2 involved a comparison between the early-cut and late-cut autumn silages.In Expt I, supplementation of the silage with barley resulted in a non-significant (P > 0.05) reduction in the proportion of digestible energy (DE) and digestible organic matter digested in the rumen and an increase in the proportions digested in the small intestine. There were also pronounced effects of barley on ruminal cellulolysis and the proportion of digestible cellulose broken down in the rumen was reduced (P < 0.05) from 0.90 to 0.77. There was an increased passage of α-linked glucose polymers to the duodenum but even with the supplemented diet 0.91 of the dietary polymers were digested in the rumen. The molar proportion of propionic acid in the rumen tended to be reduced and there were increases in the proportions of butyric acid (P < 0.01) and acetic acid.In Expt 2, the digestibility of organic matter, gross energy and cellulose in the early-cut silage was higher (P < 0.01) than in the late-cut silage but there were no significant (P < 0.05) differences between silages in the sites of digestion of these constituents. However, the molar proportion of acetic acid in the rumen was higher (P < 0.01) and the molar proportion of propionic acid was lower (P < 0.01) with the late-cut silage than with the early-cut silage.The results are discussed in relation to the voluntary intake and utilization of high-digestibility silages.

1992 ◽  
Vol 55 (3) ◽  
pp. 389-396 ◽  
Author(s):  
R. Sanderson ◽  
C. Thomas ◽  
A. B. McAllan

AbstractSeventy-two, 4-month-old, British Friesian steers were used to investigate the effects of feeding a supplement of fish meal on the voluntary intake and live-weight gain by young growing cattle given a well preserved ryegrass silage. The silage was offered either alone or mixed with 50,100 or 150 g fish meal per kg silage dry matter (DM) and the diets were offered either ad libitum or intakes were restricted to 16, 19 or 22 g dietary DM per kg live weight (LW). Intakes were recorded daily, LW weekly and in vivo apparent digestibility over one 7-day period during the 132-day trial.For animals fed ad libitum, the absolute intake of dietary DM increased linearly with an increase in the level of fish-meal supplementation such that intake when the highest level of fish meal was given was significantly higher (P < 0·01) than when silage was given alone. However, DM intake per unit LW (approx. 24 g DM per kg LW) was not affected significantly (P > 0·05).Inclusion of fish meal in the diet did not affect the apparent digestibility of dietary DM, organic matter, acid-detergent or neutral-detergent fibre (NDF) although there was a trend for slightly higher (P > 0·05) gross energy apparent digestibility when fish meal was given. Increasing the level of feeding reduced NDF digestibility. The coefficients measured at the 22 g and ad libitum levels of intake were lower (P < 0·01 and P < 0·05 respectively) than that measured at the 16 g DM per kg LW level.Animals given silage alone to appetite achieved LW gains of 0·6 kg/day. LW gains increased linearly with increasing level of feeding (P < 0·001) and increasing level offish-meal supplementation (P < 0·001).


1984 ◽  
Vol 39 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Margaret Gill ◽  
P. England

ABSTRACTGrass silage was offered ad libitum to twelve 4-month-old British Friesian steers in an incomplete Latin-square experiment. The silage was given either alone or supplemented isonitrogenously with 50 g fish meal or 63 g groundnut meal per kg silage dry matter.Both protein supplements significantly increased the intakes of dry matter and organic matter by an amount about equivalent to the (calculated) contribution of the supplement (P < 0·05); they also increased the intakes of digestible organic matter and nitrogen (P < 0·001) but with no significant difference between supplements. Protein supplementation had no effect on the intake of indigestible organic matter.The digestibility coefficients of dry matter and of organic matter were significantly increased by supplementation (P < 0·05) as were the digestibility coefficients of gross energy and of nitrogen (P < 0·001). Nitrogen retention was also increased from 1·4 to 8·2 g/day (P < 0·001), with no significant difference between supplements.


1980 ◽  
Vol 43 (3) ◽  
pp. 469-479 ◽  
Author(s):  
P. C. Thomas ◽  
D. G. Chamberlain ◽  
N. C. Kelly ◽  
M. K. Wait

Two experiments were conducted to study the digestion of nitrogenous constituents in the rumen, small intestine and caecum and colon of sheep given diets of grass silage or grass silage and barley. Three silages were used. One was made from first-harvest grass in the spring and the others from regrowth grass cut in either early autumn or late autumn. All were of perennial ryegrass (Lolium perenne) and were preserved with formic acid.Expt 1 involved a comparison between the spring silage given alone (644 g dry matter (DM)/d) and the spring silage supplemented with barley (151 g DM/d). The intakes (g/d) of total nitrogen for the silage diet and for the supplemented diet were 14.89 and 17.36. Corresponding values (g/d) for N passage were 15.55 and 18.53 (P < 0.01) at the duodenum, 6.01 and 7.09 at the ileum and 5.06 and 5.52 in the faeces. The barley supplement had no significant (P < 0.05) effect on rumen ammonia-N- concentration.Expt 2 involved a comparison between the two autumn-cut silages each offered at a level of feeding of approximately 700 g DM/d. The intakes (g/d) of total N for the early-cut silage and for the late-cut silage were 21.67 and 15.62 respectively. Corresponding values (g/d) for N passage were 17.10 and 16.96 at the duodenum, 6.65 and 6.80 at the ileum and 4.5 and 5.22 in the faeces. The concentration of NH3-N in the rumen was significantly (P < 0.001) higher with the early-cut silage than with the late-cut silage.In both experiments the rates of bacterial crude protein (N × 6.25) synthesis in the rumen, estimated using α, ε-diaminopimelic acid as a marker, were low, 142 and 161 g crude protein/kg organic matter apparently digested in the rumen for the spring silage and the spring silage and barley diets respectively, and 68 and 103 g crude protein/kg organic matter apparently digested in the rumen for the early-cut autumn silage and the late-cut autumn silage respectively. For all diets there was a relatively low contribution of bacterial crude protein to the duodenal passage of crude protein and the amounts of individual amino acids ingested in the diets had a marked influence on the amino acids passing to the duodenum and as a consequence on the mixture of amino acids taken up from the small intestine.The results are discussed in relation to the nutritive value of silage N for ruminants.


1933 ◽  
Vol 23 (2) ◽  
pp. 185-195 ◽  
Author(s):  
J. Alan Murray

SummaryNutritive values can be resolved into two factors-quantity and quality. The former is represented by the gross energy and the latter by the coefficient of availability (D/T – 0·35), where T is total and D digestible organic matter.In the natural, vegetable feeding stuffs the gross energy of the total organic matter is practically the same in all cases except those which are peculiarly rich in oil and protein (cakes, etc.). The coefficient may therefore be applied directly to the total organic matter and, subject to a correction in the case of cakes, nutritive values may be expressed in terms of available organic matter (D–0·35T). These terms may be translated into energy values or starch equivalents by simple multiplication.The method is simple and illuminating. It shows that the nutritive value of the total organic matter depends almost entirely upon its digestibility and, except in the case of cakes, only to a negligible extent upon its chemical composition. Nutritive value is not proportional to digestibility but a linear function of the same, and in substances of low digestibility, slight change in digestibility may cause manifold alteration in nutritive value.


1978 ◽  
Vol 90 (1) ◽  
pp. 47-68 ◽  
Author(s):  
K. L. Blaxter ◽  
A. W. Boyne

SUMMARYThe results of 80 calorimetric experiments with sheep and cattle, mostly conducted in Scotland, were analysed using a generalization of the Mitscherlich equation R = B(l–exp(–pG))–l, where R is daily energy retention and G daily gross energy intake, both scaled by dividing by the fasting metabolism. The relations between gross energy and metabolizable energy were also examined. Methods of fitting the Mitscherlich equation and the errors associated with it are presented.It is shown that the gross energy of the organic matter of feed can be estimated from proximate principles with an error of ±2·3% (coefficient of variation) and that provided different classes of feed are distinguished, the metabolizable energy of organic matter can be estimated from gross energy and crude fibre content with an error of ±6·9%. Parameters of the primary equation made with cattle agreed with those made with sheep and there was no evidence of non-proportionality of responses on substitution of feeds in mixtures.The efficiency of utilization of gross energy for maintenance and for body gain of energy was related to the metabolizability of gross energy and, in addition, to fibre or to protein content. Prediction equations are presented which describe these relationships.It is shown that the primary equation can be manipulated to express a number of biological concepts and that its two parameters B and p can be simply derived from estimates of the two efficiency terms for maintenance and production.The results are discussed in relation to the design of feeding systems for ruminant animals and to the derivation of optima in their feeding.


1973 ◽  
Vol 53 (2) ◽  
pp. 257-263 ◽  
Author(s):  
G. PELLETIER ◽  
E. DONEFER

Three yearling Cheviot × Suffolk ewes and three Columbia wethers were confined in metabolic cages and fed ad libitum fresh and dried marrow-stem kale (Brassica oleracea var. acephala D.C.) harvested in mid- and late October. Chemical analyses of the forages indicated no marked effects on any of the plant constituents due to drying or advancing maturity. Digestibility measurements demonstrated that marrow-stem kale (MSK) was a highly digestible material with an average dry matter digestibility of 78%. The fresh forages had higher (P < 0.05) dry matter and gross energy digestibility values than the dried form. Dry matter digestibility coefficients were higher (P < 0.05) for late October as compared with the earlier harvest. A trend toward higher (P > 0.05) voluntary intake values due to drying maturity was observed with an average relative intake of 80%. The nutritive value index averaged 65, thus indicating a digestible energy intake similar to a high-quality (legume) forage.


1991 ◽  
Vol 71 (1) ◽  
pp. 107-114 ◽  
Author(s):  
Z. Mir ◽  
S. Bittman ◽  
L. Townley-Smith

Two trials were conducted to evaluate the voluntary intake and digestibility of kochia (Kochia scoparia) as hay or silage for sheep. In Trial 1, kochia (KOC) hay substituted for alfalfa hay (AA) at 0, 25, 50 or 75% of complete diets, or 50% AA or 50% KOC with barley (BAR) were fed to 24 mature wethers in a completely randomized design experiment. As the level of KOC in the diet increased, dry matter intake (DMI) of wethers decreased linearly. There were no differences (P > 0.05) in dry matter or fiber digestibilities among the four diets containing AA and KOC hay. Nitrogen and gross energy digestibilities increased linearly (P < 0.05) with decreasing levels of dietary KOC. In trial 2, KOC silage prepared from two ecotypes of KOC (southern and northern), cut at two different dates and fed in a 50:50 combination with AA silage were compared with a diet containing AA silage. DMI and nutrient digestibilities of the AA silage diet were higher (P < 0.05) than those for the diets containing KOC. Results indicate that KOC hay can be fed in high forage or concentrate diets at levels between 25 and 50% of the diet without adverse effects on intake or digestibility. Results also demonstrate that KOC can be preserved by ensiling and that KOC silage can be used in combination with AA silage in diets for sheep. Key words: Kochia, sheep, digestibility, hay, silage


1972 ◽  
Vol 27 (1) ◽  
pp. 39-50 ◽  
Author(s):  
J. C. Macrae ◽  
M. J. Ulyatt ◽  
P. D. Pearce ◽  
Jane Hendtlass

1. In two experiments, sheep prepared with a rumen cannula and with re-entrant cannulas in the duodenum and ileum were continuously fed on diets of dried grass, dried grass plus formalin-treated casein, or dried grass plus untreated casein. Paper impregnated with chromic oxide was given once daily via the rumen fistula.2. In ten 24 h collections of digesta entering the duodenum and eleven 24 h collections of digesta reaching the ileum of sheep given dried grass, there were highly significant correlations between the 24 h flows of Cr marker and the corresponding flows of dry matter, organic matter, nitrogen, gross energy, hemicellulose and cellulose (P < 0.01) at both sites.3. Daily amounts of non-ammonia N and of individual amino acids entering and leaving the small intestine and of total N excreted in faeces and urine are given.4. Net retention of supplementary N was 36% when the supplement was administered as formalin-treated casein, but only 17% when it was administered as untreated casein.5. Formalin treatment of casein significantly increased the daily amounts of non-ammonia N entering the small intestine (P < 0.01) and the amounts of non-ammonia N apparently absorbed therein (P < 0.05).6. Apparent absorption of amino acids from the small intestine was significantly greater (P < 0.05) with treated casein than with untreated casein. There were relative increases in the small amounts of several free amino acids measured, including taurine, in the ileal digesta of sheep receiving the treated casein supplement.


1973 ◽  
Vol 24 (6) ◽  
pp. 889 ◽  
Author(s):  
RF Thornton ◽  
DJ Minson

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.


2002 ◽  
Vol 82 (4) ◽  
pp. 621-626 ◽  
Author(s):  
H. A. Lardner ◽  
S. B. M. Wright ◽  
R. D. H. Cohen ◽  
P. Curry ◽  
L. MacFarlane

Rejuvenation of forage stands is probably the most economic and practical method to improve production and quality of forage stands. Animal data are ultimately needed to validate the viability of the rejuvenation technique. This study determined animal responses to changes in forage nutrient composition following three methods of rejuvenation. Smooth bromegrass (Bromus inermis L.) and alfalfa (Medicago sativa L.) hay was harvested from rejuvenated plots on Black Chernozemic and Gray Luvisolic soils in Saskatchewan and fed to 24 ram lambs. The hay was harvested at two stages of maturity from plots that underwent the following rejuvenation techniques, selected to provide a range of responses: deep-banded liquid plus broadcast granular fertilizer (providing 200 kg N ha-1, 90 kg P2O5 ha-1, 46 kg K2O ha-1, 24 kg S ha-1), spring burn, and control. As maturity advanced, digestible organic matter intake (DOMI) (g d-1 kg-0.75) decreased (P < 0.05) for all diets harvested from burn and fertilizer plots. DMI (g d-1) and DOMI were always greater (P < 0.05) for hay (both early or late harvest) from the rejuvenated plots than from control plots. Grass-legume hay harvested early from spring burn treatment from the Gray Luvi solic soil site had a greater (P < 0.05) voluntary intake, (85.4 g d-1 kg-0.75) as compared with forage from control plots (76.2 g d-1 kg-0.75). Apparent digestibilities of DM and organic matter were greater (P < 0.01) for early harvested forage from control plots at the Gray Luvisolic soil site than early harvested hay from the fertilized plots. Metabolizable energy content was higher (P < 0.05) for early harvested hay from burn and fertilized plots at the Black soil site than hay from control plots. These results suggest that existing forage species, if harvested early, can be responsive to rejuvenation, resulting in improved animal performance. Key words: Rejuvenation, fertilizer, burn, lamb, grass-legume hay


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