The nutritive value of silages

1978 ◽  
Vol 40 (2) ◽  
pp. 205-219 ◽  
Author(s):  
N. C. Kelly ◽  
P. C. Thomas

1. Two calorimetric experiments were conducted to study the utilization of energy in sheep given diets of grass silage or grass silage and barley. Three silages were investigated. One was made from first-harvest grass in the spring (S) and the others from regrowth cut either early or late in the autumn (E and L respectively). All were of perennial ryegrass (Lolium perenne) and preserved with formic acid. Each silage was given at two levels of feeding, the lower providing approximately a maintenance energy intake. The S and L silages were also given supplemented with barley.2. The digestibilities of organic matter, cellulose and energy in the silages were high. Measured at maintenance, digestible energy (de) contents (MJ/kg dry matter (dm)) were 11.83, 14.67 and 12.90 for S, E and L respectively. The de contents of the S and E silages were depressed at the higher level of feeding but the effect was offset by changes in the energy losses as methane and urine. Metabolizable energy (me) contents (MJ/kg dm) for the three silages, S, E and L were respectively 9.88, 12.54 and 10.73 at the low level of feeding and 9.91, 11.99 and 11.08 at the high level of feeding. The mean me content of barley calculated by difference was 13.76 MJ/kg dm.3. The mean efficiencies of utilization of me for maintenance (km) for the S, E and L silages were 0.69, 0.71 and 0.68 respectively. Corresponding values for fattening (kf) were 0.21, 0.57 and 0.59. Excepting the kf for the S silage which was low, observed efficiencies were in broad agreement with those predicted by the equations of the Agricultural Research Council (1965). Similar agreement was obtained with all diets consisting of silage and barley.

1970 ◽  
Vol 74 (2) ◽  
pp. 311-314 ◽  
Author(s):  
F. W. Wainman ◽  
K. L. Blaxter ◽  
J. D. Pullar

SUMMARYCalorimetric experiments were made with a complete extruded diet for ruminants, ‘Ruminant Diet A’ prepared by Messrs U.K. Compound Feeds Ltd. Twelve determinations of energy and nitrogen retention were made using sheep and it was found that the diet had a metabolizable energy value of 2–32 kcal/g organic matter, and the net availabilities of its metabolizable energy were 42–7 % for fattening and 68–0 % for maintenance. These values agreed well with those predicted from equations published by the Agricultural Research Council. On a dry basis the starch equivalent was 38–3 %.


1989 ◽  
Vol 61 (1) ◽  
pp. 59-65 ◽  
Author(s):  
J. S. Chrisp ◽  
A. R. Sykes ◽  
N. D. Grace

1. Two groups of eight 6–7-month-old wether lambs were offered either a frozen ryegrass (Lolium perenne L.)-white clover (Trifolium repens L.) pasture or a ryegrass-white clover hay, containing 12.1 and 6.4 g calcium/ kg dry matter (DM) respectively. Within groups the amounts offered to individual sheep ranged from 0.5 to 2.0 times the estimated maintenance energy requirements.2. A single intravenous injection of 150 μCi 45Ca as CaCl2. 2H2O, and stable balances were used to determine absorption, faecal endogenous loss and balance of Ca.3. Faecal endogenous loss of Ca increased by 1.2 mg/kg body-weight (W) per d with each g/kg W per d increase in DM intake regardless of the diet. At any DM intake the mean faecal endogenous loss was 5.5 mg/kg W per d higher in the sheep offered the frozen herbage diet when compared with those on the hay diet. At any Ca intake the mean faecal endogenous loss was 6.9 mg/kg W higher in sheep offered the hay diet compared with those on the frozen herbage.4. At feeding levels of about 1.5–2 times the estimated maintenance energy requirement the observed faecal endogenous loss of Ca ranged from 35 to 50 mg/kg W per d, which is two- to threefold greater than the present estimate of the Agricultural Research Council (1980) of 16 mg/kg W per d.5. A simple model to explain the variation in faecal endogenous loss of Ca between the present study with young sheep and that with lactating ewes (Chrisp et al. 1989) also offered herbage diets is developed, which incorporates the concept of a true endogenous loss related to DM intake and a net endogenous loss reflecting the extent of re-absorption of Ca endogenous losses within the gastrointestinal tract.


1969 ◽  
Vol 11 (3) ◽  
pp. 389-397 ◽  
Author(s):  
T. J. Forbes ◽  
J. J. Robinson

SUMMARYTwo experiments were carried out to study the energy requirements of young fattening lambs for maintenance and production. Forty weaned lambs were used in each experiment, 20 being allocated to a high level of feeding (900 g air-dry feed per day) and 20 to a low level (540 g). The animals used in Experiment 1 were approximately 12 months of age and their mean live weight was 35·3±4·03 kg. Those in Experiment 2 were approximately seven months of age and their mean live weight was 36·7 ± 4·57 kg. Experiment 1 continued for 100 days and Experiment 2 for 47 days. Three digestibility trials, involving three animals from each feeding level, were carried out during the course of each experiment to obtain precise estimates of digestible organic matter intake (DOMI). The estimated mean DOMI required for maintenance for a 45-kg lamb was 400 g (0·88 lb) or 1500 kcal metabolizable energy per day. The estimated maintenance requirement was not affected by the age of the animal. The DOMI required for production ranged from 1·55 kg per kg live-weight gain for the younger animals to 1·71 kg for the older animals. Both these requirements were lower than those obtained by other workers and those suggested by the Agricultural Research Council (1965).


1978 ◽  
Vol 91 (2) ◽  
pp. 483-486 ◽  
Author(s):  
E. R. Ørskov ◽  
D. A. Grubb

SUMMARYMilled barley straw, either untreated or treated with 70 g of NaOH/kg straw was supplemented with four levels of urea, namely 0, 6, 12 or 18 g/kg and fed ad libitum to young sheep. For the untreated straw, dry-matter intakes were (g/day) 423, 451, 441 and 463, while the digestibility of organic matter was 458, 467, 490 and 483 g/kg, respectively. For the treated straw, the intakes of dry matter were 355, 402, 531 and 567 g/day and the digestibility of organic matter was 423, 480, 589 and 628 g/kg respectively.The different responses to urea supplementation of treated and untreated straw are discussed in relation to a new system of estimating protein requirements for ruminants put forward by the Agricultural Research Council.


Author(s):  
D.J. Thomson ◽  
M.J. Haines ◽  
S.B. Cammell ◽  
M.S. Dhanoa

The Starch Equivalent (SE) system devised by Kellner for expressing the energy requirements of ruminants and the energy value of feeds was used in Britain from 1912. Metabolizable energy (ME) was proposed (Agricultural Research Council, 1965) and adopted (MAFF, DAFS and DANI, Technical Bulletin 33, 197S), as a basis for a new system relating diet to the energy requirements of animals. Additional information was incorporated in the extensive Technical Review (The Nutrient Requirements of Ruminant Livestock, 1980). Metabolizable energy was retained, and animal performance it was claimed, was predicted more precisely with ME than SE. Results presented in this paper are for the comparison, and interpretation, of observed and predicted (Technical Bulletin 33) rates of gain, and other components of the ME system, for growing lambs and cattle fed forage and mixed forage and concentrate diets.


1999 ◽  
Vol 133 (4) ◽  
pp. 409-417
Author(s):  
D. E. KIRKPATRICK ◽  
R. W. J. STEEN

An experiment was carried out in 1994 to examine energy and nitrogen utilization of lambs offered two contrasting grass-based diets. The two forages, which were from the same parent herbage, were grass silage and grass which was conserved by freezing. They were offered as sole diets or supplemented with either 250 or 500 g concentrates per kg total dry matter intake (DMI) to give a total of six experimental treatments. Seventy-two Dutch Texel × Greyface (Border Leicester × Blackface) lambs, consisting of 36 males which were initially 36 (S.D. 4·9) kg liveweight and 36 females which were initially 34 (S.D. 2·5) kg liveweight were used. Ensiling significantly increased apparent digestibility of dry matter, energy and nitrogen (P<0·001), but had no significant effect on methane energy loss as a proportion of gross energy intake, metabolizable energy intake (MEI), heat production, energy retained, efficiency of utilization of energy for growth (kg) or nitrogen retention. Supplementation of forage with concentrates resulted in a curvilinear decrease in heat production expressed as a proportion of MEI (P<0·05) and a linear increase in energy retention, expressed as an absolute value or as a proportion of MEI (P<0·05). Supplementation of forage tended to increase kg when calculated using Agricultural Research Council estimates of maintenance energy requirements, but had no significant effect when alternative estimates of maintenance were used. It is concluded that ensiling had no effect on efficiency of utilization of energy or nitrogen as measured by indirect calorimetry.


1988 ◽  
Vol 46 (2) ◽  
pp. 169-179 ◽  
Author(s):  
H. D. St C. Neal ◽  
M. Gill ◽  
J. France ◽  
A. Spedding ◽  
S. Marsden

AbstractEquations for the prediction of forage dry-matter intake, metabolizable energy (ME), rumen degradable protein and undegraded protein, based on those in the current Agricultural Research Council system, were incorporated into a computer program designed to be used by livestock advisors for on-farm rationing of beef cattle. The predictions of silage intake and live-weight gain are compared with experimental data.Voluntary intake of grass silage was generally over-estimated by the program by proportionately at least 0·06, with a root mean square error of ±0·18 of the mean observed silage intake for the all-silage rations. The prediction of ME requirement for observed production had an error of +0·15 of average ME intake but the calculations of ME intake were themselves dependent on the predictions of the ME concentrations of the silages and supplements. Similarly the comparison of protein supply with requirement was highly dependent on the value assigned to N-degradability. However, the program can be used to assess how changes in the input values would affect ration formulation.The mathematical basis of the program is described in the Appendix.


1988 ◽  
Vol 110 (2) ◽  
pp. 411-413 ◽  
Author(s):  
D. Scott ◽  
W. Buchan

The Agricultural Research Council (1980) has recently published revised estimates of the phosphorus requirements for ruminants. These new estimates are considerably lower than those formerly recommended (Agricultural Research Council, 1965) and some concern has been expressed as to whether or not they are adequate (Cooke, 1982; Todd, 1983).


1974 ◽  
Vol 19 (2) ◽  
pp. 141-148 ◽  
Author(s):  
J. Harkins ◽  
R. A. Edwards ◽  
P. Mcdonald

SUMMARYA simplified Net Energy system for ruminants is described. It is based on the Metabolizable Energy system outlined by the Agricultural Research Council (1965) and enables a non-iterative approach to be used in the formulation of rations. The method is suitable for use in linear programming work and is illustrated, with appropriate tables, for growing cattle.


2009 ◽  
Vol 33 (6) ◽  
pp. 1637-1642 ◽  
Author(s):  
Rodrigo Palomo de Oliveira ◽  
Juan Rámon Olalquiaga Perez ◽  
Joel Augusto Muniz ◽  
Antonio Ricardo Evangelista ◽  
José Camisão de Souza ◽  
...  

The experiment was carried out in the sheep division of Universidade Federal de Lavras, aiming to evaluate the effect of different concentrate : voluminous ratio on the performance of Santa Inês lamb after wean. 40 lambs, male uncastrated, were used and fed with four different diets: diet A (100% concentrate), diet B (75:25 concentrate : voluminous) , diet C (50:50 concentrate : voluminous) , diet D (25:75 concentrate : voluminous). The experimental diets were isoproteic, differing only on its levels of concentrate : voluminous and balanced to meet the nutritional demands according to the recommendation of the Agricultural Research Council (1980). The experimental period was not pre-established, because it corresponded to the necessary period for the last lamb to reach the live weight of 35kg. The dry matter consumption (DMC), crude protein consumption (CPC), fiber in neutral detergent consumption (FNDC) and fiber in acid detergent consumption (FADC), were affected by the different concentrate : voluminous ratio, in which, the animals that received diets with higher concentrate inclusion presenting better results for the variables related to the development. The lambs fed with the diet containing higher inclusion of voluminous did not present weight gain, on the contrary, presented weight loss, since none of the animals reached slaughter weight and the mortality rate was extremely high (80%).


Sign in / Sign up

Export Citation Format

Share Document