An evaluation of prediction equations incorporated in a computer program to ration beef cattle

1988 ◽  
Vol 46 (2) ◽  
pp. 169-179 ◽  
Author(s):  
H. D. St C. Neal ◽  
M. Gill ◽  
J. France ◽  
A. Spedding ◽  
S. Marsden
Keyword(s):  
Beef Cattle ◽  
Computer Program ◽  
Agricultural Research ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Mathematical Basis ◽  
Agricultural Research Council ◽  
The Mean ◽  
Protein Supply ◽  
On Farm

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.

Responses of British Friesian steers with or without implants of oestradiol-17β to undegradable dietary protein

1988 ◽  
Vol 46 (2) ◽  
pp. 181-193 ◽  
Author(s):  
J. R. Newbold ◽  
P. C. Garnsworthy ◽  
P. J. Buttery ◽  
D. J. A. Cole ◽  
W. Haresign
Keyword(s):  
Agricultural Research ◽  
Live Weight ◽  
Soya Bean ◽  
Metabolizable Energy ◽  
Protein Nutrition ◽  
Agricultural Research Council ◽  
Bean Meal ◽  
Soya Bean Meal ◽  
Protein Supply ◽  
Degradable Protein

AbstractThe ability of the protein nutrition scheme proposed by the Agricultural Research Council (ARC, 1980, 1984) to predict responses to protein supply was examined in two experiments. In experiment 1, groups of nine British Friesian steers implanted with oestradiol-17β and nine non-implanted steers were fed from 133 to 300 kg live weight on each of four all-concentrate diets (metabolizable energy (ME) = 12 MJ/kg dry matter (DM)) containing ratios of soya-bean meal and formaldehyde-treated soya-bean meal such that undegradable protein (UDP) concentration was 19, 25, 32 or 42 g/kg DM. Rumen degradable protein (RDP) concentration was relatively constant (111 to 116 g/kg DM). Implantation did not affect DM intake (DMI, g/kg M0·75). Both live-weight gain (LWG) and food conversion efficiency (FCE) (LWG/DMI) were greater (P < 0·05) for the implanted cattle (LWG = 1·41 (s.e. 0·04) kg/day; FCE = 0·24 (s.e. 0·02)) than for the non-implanted cattle (LWG = 1·23 (s.e. 0·05) kg/day; FCE = 0·22 (s.e. 0·02)). There were no dietary effects on either DMI or FCE. In the non-implanted steers, UDP did not affect LWG but, for the implanted steers, there were positive, linear responses in LWG to both UDP concentration (P = 0·048) and UDP intake (P = 0·026). In experiment 2, groups of eight implanted steers were fed from 132 to 300 kg live weight on each of six diets (ME = 12 MJ/kg DM, soya-bean meal and formaldehyde-treated soya-bean meal as chief protein sources) supplying 17, 26, 34, 39, 54 and 82 g UDP per kg DM and concentrations of RDP up to 1·5 times ARC recommendations. There was no effect of UDP on either DMI or FCE but positive, linear responses in LWG to both UDP concentration (P = 0·019) and UDP intake (P = 0·010). In both experiments, mean DMI exceeded that predicted by ARC (1980) (P < 0·05). LWG predicted by the ME system and the ARC protein scheme was not significantly different from observed LWG for non-implanted steers, but was an underestimate of observed LWG for implanted steers (P = 0·002 in experiment 1, P < 0·001 in experiment 2). Observed responses in LWG to UDP concentration were also poorly predicted (regressions of observed on predicted LWG: experiment 1, r2 = 0·12, residual s.d. = 0·126; experiment 2, r2 = 0·004, residual s.d. = 0·119). It was concluded that oestradiol-17p has significant effects on responses in LWG to UDP, which are not predicted by the current ARC (1980, 1984) protein nutrition scheme.

A study of the energy requirements of weaned lambs

1969 ◽  
Vol 11 (3) ◽  
pp. 389-397 ◽  
Author(s):  
T. J. Forbes ◽  
J. J. Robinson
Keyword(s):  
Organic Matter ◽  
Research Council ◽  
Agricultural Research ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Feeding Level ◽  
Agricultural Research Council ◽  
Digestible Organic Matter ◽  
High Level

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).

The nutritive value of silages

1978 ◽  
Vol 40 (2) ◽  
pp. 205-219 ◽  
Author(s):  
N. C. Kelly ◽  
P. C. Thomas
Keyword(s):  
Dry Matter ◽  
Research Council ◽  
Nutritive Value ◽  
Agricultural Research ◽  
Metabolizable Energy ◽  
Broad Agreement ◽  
Grass Silage ◽  
Agricultural Research Council ◽  
The Mean ◽  
High Level

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.

Protein nutrition of growing cattle: food intake and growth responses to rumen degradable protein and undegradable protein

1987 ◽  
Vol 45 (3) ◽  
pp. 383-394 ◽  
Author(s):  
J. R. Newbold ◽  
P. C. Garnsworthy ◽  
P. J. Buttery ◽  
D. J. A. Cole ◽  
W. Haresign
Keyword(s):  
Food Intake ◽  
Agricultural Research ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Growth Responses ◽  
Protein Nutrition ◽  
Agricultural Research Council ◽  
Four Levels ◽  
Current Energy ◽  
Degradable Protein

ABSTRACTGroups of eight Friesian steers were given one of eight diets from 114 to 300 kg live weight. The iso-energetic diets were formulated to supply four levels of protein degradability within two concentrations of crude protein (CP), giving a range of rumen-degradable protein (RDP) and undegradable dietary protein (UDP) concentrations both above and below Agricultural Research Council (1980) recommendations. There were significant (P < 0·05), positive, linear responses of mean daily dry-matter (DM) intake (DMI) (g/kg M°75) to RDP concentration (g/kg DM) for both the low CP diets (DMI = -98·0 + 1·76 (RDP); P = 0·013) and the high CP diets (DMI = -157·5 + 218 (RDP; P = 0017). For the high CP diets, there was a significant (P = 0·045) positive, linear response of live-weight gain (LWG) (kg/day) to UDP concentration (LWG = 0·47 + 0·017 (UDP); P = 0·045). No such response was observed for the low CP diets, where the range of UDP concentrations supplied was smaller than expected. For both the low and high CP diets, LWG decreased as metabolizable energy, UDP and RDP intake increased. These negative responses to nutrient intake were reflected in a wide discrepancy between observed rates of gain and those predicted by current energy and protein nutrition systems. Interactions between food intake and digestive processes, which obstruct effective interpretation of these results, should form an explicit part of any revised protein nutrition scheme.

The influence of a formulated excess of rumen degradable protein or undegradable protein on milk production in dairy cows in early lactation

1988 ◽  
Vol 46 (1) ◽  
pp. 13-22 ◽  
Author(s):  
B. K. Sloan ◽  
P. Rowlinson ◽  
D. G. Armstrong
Keyword(s):  
Dairy Cows ◽  
Milk Fat ◽  
Fish Meal ◽  
Agricultural Research ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Grass Silage ◽  
Agricultural Research Council ◽  
Condition Score ◽  
Degradable Protein

ABSTRACTFollowing a 3-week covariance period, 30 group-housed dairy cows were individually given one of three diets from week 4 to week 13 of lactation to determine any possible advantage in milk yield and production of feeding levels of undegradable protein (+UDP) or rumen-degradable protein (+RDP) above the minimum levels (control) proposed by the Agricultural Research Council (ARC, 1984). The three concentrates given were formulated to be of equivalent metabolizable energy (ME, 13·5 MJ/kg dry matter (DM)) concentration and each consisted of rolled barley plus a protein supplement: control (crude protein (CP), 129 g/kg DM) 0·35 kg DM fish meal per day; +UDP (CP, 167 g7kg DM) 1·0 kg DM fish meal per day; and +RDP (CP, 167 g/kg DM) 1+5 kg DM soya per day. For each group the total ‘concentrate’ allowance per animal per day was 11·6 kg fresh weight and was given in three equal feeds. Grass silage (CP 122 g/kg DM, ME 106 MJ/kg DM) was given ad libitum. For the control, +UDP and +RDP treatments, respectively, mean grass silage intakes were 8·29, 8·62 and 8·65 kg/day and mean milk yields were 26·6, 26·3 and 26·1 kg/day. These were not significantly different (P > 0·05). Milk fat concentration was lower (P < 0·05) for the +UDP treatment (36·4 g/kg) in comparison with the control (38·6 g/kg) or the +RDP treatment (39·7 g/kg) but no other milk constituent was significantly influenced by treatment. There was a trend for a greater live-weight gain with treatment +UDP (0·81 kg/day) compared with the other two treatments (control 0·50, +RDP 0·51 kg/day) but there were no differences in condition-score change between treatments. In this trial there was no advantage to feeding formulated levels of UDP or RDP above those proposed by ARC (1984).

An equation, suitable for computer use, based on the ARC feeding system to determine the energy requirements of growing and fattening cattle

1972 ◽  
Vol 14 (1) ◽  
pp. 17-23 ◽  
Author(s):  
C. A. Zulberti ◽  
J. T. Reid
Keyword(s):  
Weight Gain ◽  
Computer Use ◽  
Agricultural Research ◽  
Energy Requirement ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Energy Concentration ◽  
Feeding System ◽  
Agricultural Research Council ◽  
Forward Calculation

SUMMARYBased on the Agricultural Research Council's feeding system, equations were developed that allow the calculation of the metabolizable energy requirements for maintenance and weight gain by cattle, separately or combined. A general equation was developed for the straight-forward calculation of the total metabolizable energy requirements of growing and fattening cattle for any combination of body weight, rate of weight gain, age, level of muscular work, and metabolizable energy concentration of the diet. The estimates of energy requirement made by the use of this equation are in excellent agreement with those made by the Agricultural Research Council using an iterative method.In addition to avoiding the awkward iterative process, the equations proposed are readily adaptable to computer use.

A comparison of wheat and barley as supplements to grass silage for finishing beef cattle

1993 ◽  
Vol 56 (1) ◽  
pp. 61-67 ◽  
Author(s):  
R. W. J. Steen
Keyword(s):  
Beef Cattle ◽  
Spring Barley ◽  
Live Weight ◽  
Ammonia Nitrogen ◽  
Carcass Composition ◽  
Metabolizable Energy ◽  
Crude Fibre ◽  
Grass Silage ◽  
Soya Bean Meal ◽  
Finishing Beef Cattle

AbstractTwo randomized-block experiments were carried out to examine the relative value of wheat and barley as supplements to grass silage for finishing beef cattle. In each experiment unwilted, formic acid-treated silage was offered ad libitum and supplemented with 500 g soya-bean meal and 50 g minerals and vitamins to 44 12-month-old bulls for 157 and 172 days in experiments 1 and 2 respectively. Twelve of the animals also received 2·5 kg rolled spring barley (LB), 12 received 4·0 kg barley (HB) and 20 received 3·25 kg rolled wheat (W). For experiments 1 and 2 respectively the barley contained 796 and 787 g dry matter (DM) per kg; 118 and 105 g crude protein (CP) per kg DM; 47 and 57 g crude fibre per kg DM; the wheat contained 845 and 800 g DM per kg; 112 and 116 g CP per kg DM; 23 and 25 g crude fibre per kg DM; and the silages contained 190 and 177 g DM per kg; 153 and 176 g CP per kg DM; 80 and 104 g ammonia-nitrogen per kg total nitrogen. On average over the two experiments, for treatments LB, HB and W respectively, silage DM intakes were 5·4, 4·7 (s.e. 0·14) and 4·9 (s.e. 0·11) kg/day; total DM intakes 7·9, 8·3 (s.e. 0·14) and 8·1 (s.e. 0·11) kg/day; metabolizable energy intakes 91·4, 97·8 and 94·2 MJ/day; live-weight gains 1·04,1·19 (s.e. 0·029) and 1·10 (s.e. 0·023) kg/day and carcass gams 0·65, 0·77 (s.e. 0·017) and 0·70 (s.e. 0·013) kg/day. It is concluded that the feeding value of wheat was proportionately 0·98 of that of barley for finishing beef cattle when given as a supplement to grass silage, and that the type of cereal offered did not affect silage intake or carcass composition.

The nutritive value for ruminants of a complete processed diet based on barley straw

1970 ◽  
Vol 74 (2) ◽  
pp. 311-314 ◽  
Author(s):  
F. W. Wainman ◽  
K. L. Blaxter ◽  
J. D. Pullar
Keyword(s):  
Organic Matter ◽  
Research Council ◽  
Nutritive Value ◽  
Agricultural Research ◽  
Nitrogen Retention ◽  
Metabolizable Energy ◽  
Barley Straw ◽  
Energy Value ◽  
Agricultural Research Council

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 %.

6.1 The Adoption of a Protein System in Nutritional Advisory Work

1982 ◽  
Vol 6 ◽  
pp. 121-128
Author(s):  
B. R. Cottrill
Keyword(s):  
Dietary Protein ◽  
Research Council ◽  
Agricultural Research ◽  
Protein System ◽  
Agricultural Research Council ◽  
Experimental Findings ◽  
On Farm ◽  
Farm Livestock ◽  
New Protein

The concept of feeding standards for farm livestock has developed in Europe during the last two centuries (Tyler, 1975). During that time, and in the light of both experimental findings and on-farm observations, feeding standards have continued to evolve both in concept and detail. Such developments are exemplified in the recent publications by the Agricultural Research Council (1980), Hagemeister and Kaufmann (1974), Burroughs, Trenkle and Vetter (1974), and Jarrige, Journet and Vérité (1978) containing new proposals for the evaluation of dietary protein for ruminants. In view of these developments, the time is right to consider the adoption of a new protein system in nutritional advisory work.

The me system : The biological basis

1986 ◽  
Vol 1986 ◽  
pp. 60-60
Author(s):  
D.J. Thomson ◽  
M.J. Haines ◽  
S.B. Cammell ◽  
M.S. Dhanoa
Keyword(s):  
Research Council ◽  
Agricultural Research ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Nutrient Requirements ◽  
Animal Performance ◽  
Biological Basis ◽  
Additional Information ◽  
Agricultural Research Council ◽  
New System

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.

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