The influence of dietary protein and energy concentration on the growth of Merino weaner sheep

1980 ◽  
Vol 20 (104) ◽  
pp. 308 ◽  
Author(s):  
BA McGregor ◽  
JW McLaughlin

The influence of the dietary concentration of protein and energy on the growth of Merino wether weaners in pens, was studied in a factorial experiment. There were two digestible energy concentrations, (12.4 and 14.2 MJ DE kg-1 DM) x five protein concentrations (9-21% CP), three replicates (each of one animal). Diets were offered ad libitum, and nitrogen and energy retention were determined by the comparative slaughter technique. Initially, the mean weight of all treatment groups was 15.5 kg liveweight (12 weeks of age), and the experiment concluded 14 weeks later. Daily dry matter intake, liveweight gain, wool growth and total body nitrogen retention increased linearly as dietary crude protein concentration increased. Higher energy concentrations reduced dry matter intake and liveweight gain, and increased wool growth. Approximately 21 % of the digestible energy intake was retained. Regressions relating carcase and non-carcase composition to compartment weight, are presented. The fastest and most efficient gain in liveweight occurred with the ration containing 20% CP, at the lower energy concentration. It is suggested that for high levels of production with Merino weaners, rations should contain at least 18% CP.

1995 ◽  
Vol 31 (10) ◽  
pp. 137-141 ◽  
Author(s):  
M. Rodehutscord ◽  
E. Pfeffer

Semi-purified diets containing 19.6 MJ digestible energy/kg dry matter were fed to groups of rainbow trout initially weighing, on average, 53 g/trout. In a series of 12 diets, mono sodium phosphate replaced a silica carrier aiming at a range in P concentration from 1.0 to 10.9 g/kg dry matter. Each diet was fed to a group of 20 trout. During the trial of 53 feeding days, response of dry matter intake, weight gain, feed conversion ratio and P concentration of the gain followed exponential functions. For achieving 95 % of the potential maximum gain, a dietary concentration of 3.7 g P per kg dry matter was required. However, 5.3 g P per kg dry matter were required for achieving high P concentration in the gain. P was utilized most efficiently at a dietary concentration of 2.5 g/kg dry matter. A dietary P concentration of 0.25 g available P per MJ digestible energy was recommended to be sufficient for trout diets.


1979 ◽  
Vol 29 (2) ◽  
pp. 245-255 ◽  
Author(s):  
D. J. Thomson ◽  
S. B. Cammell

ABSTRACTA primary growth crop of perennial ryegrass (cv. S24), containing 17% crude protein and 9·9 MJ metabolizable energy/kg dry matter, was artificially dried, ground through a 3·0 mm screen and pelleted either without further treatment (C), or after the application of formaldehyde (T) at a rate of 1 g/100 g crude protein. The C and T diets were each fed to 20 lambs for 77 days. Diets C and T were given ad libitum and at three lower planes of nutrition. Similar amounts of dry matter, nitrogen and digestible energy were consumed at each of the four planes of nutrition by lambs fed diets C and T. Carcass energy, fat and protein retention, and total body energy retention were measured by the comparative slaughter technique and did not differ between the diets (P> 0·05). Metabolizable energy intake was calculated from digestible energy intake using the factor 0·81. The efficiency of utilization of the metabolizable energy for growth and fattening (kf) and the net energy value were calculated by linear regression analysis from the total body energy retention, the calculated metabolizable energy intake and dry-matter intake data scaled to M0·75. They did not differ between the diets (P > 0·05), and were 0·370 (C) and 0·431 (T) for kf, and 2·09 (C) and 1·97 MJ/kg dry matter (T) for net energy.


1965 ◽  
Vol 7 (3) ◽  
pp. 303-308 ◽  
Author(s):  
H. B. Bowers ◽  
T. R. Preston ◽  
N. A. MacLeod ◽  
I. McDonald ◽  
Euphemia B. Philip

SUMMARY1. Nitrogen balance studies were made on 8 Friesian steers given allconcentrate diets containing fish meal, soya bean meal, groundnut meal or cottonseed meal.2. There were no differences in nitrogen retention but voluntary feed intake was significantly lower on the fish meal diet.3. Adjustment of nitrogen retention to constant dry matter intake resulted in significantly higher values for the diets containing fish meal and cottonseed meal than for the others.4. Rumen pH, rumen ammonia and blood urea were all much lower on the fish meal diet.


1979 ◽  
Vol 30 (6) ◽  
pp. 1185 ◽  
Author(s):  
PT Doyle ◽  
RJ Moir

Two experiments were carried out to study the excretion and retention of nitrogen and sulfur when intraruminal infusions of DL-methionine were given to sheep. Merino wethers were fed on a 50:50 oaten chaff: lucerne chaff ration at different levels of dry matter intake (DMI), either as chaff or ground and pelleted, and with or without intraruminal infusions of DL-methionine. Liveweight gain in experiment 1, and the rate of wool growth and sulfur incorporation into wool were also measured. [35S]L-methionine was used to trace sulfur excretion from the supplement. Increasing the DMI increased (P < 0.001) nitrogen and sulfur excretion in both faeces and urine, but also increased (P < 0.001) the apparent retention of nitrogen and sulfur. The excretion of nitrogen and sulfur was not significantly affected by the form in which the basal ration was supplied, but sulfur retention did improve (P < 0.05) when the ration was given as chaff. DL-methionine supplements resulted in large increases (P < 0.001) in the excretion of total and inorganic sulfate sulfur in urine, and there was a tendency for urinary neutral sulfur excretion to increase. The amino acid supplement did not affect faecal sulfur excretion except at the lower level of feed intake in experiment 2. Differences in the amount of sulfur, from DL-methionine and [35S]L- methionine injections given into the rumen, excreted in faeces and urine indicate possible differences in the metabolism of the amino acid isomers. Increasing DMI resulted in improved (P < 0.001) rates of liveweight gain and wool growth; DL-methionine infusions had no effect. Further, estimates of sulfur incorporation into wool indicate that very little supplementary methionine was utilized at the follicular sites despite increased sulfur retention. The patterns of sulfur excretion suggest that the added methionine was rapidly and virtually completely dissimilated in the rumen. It is concluded that production responses to dietary methionine supplementation occur only under sulfur-deficient conditions or occasionally where degradation is avoided. _____________________ *Part II, Aust. J. Biol. Sci., 32: 65 (1979).


1976 ◽  
Vol 16 (83) ◽  
pp. 818 ◽  
Author(s):  
NP McMeniman

Mulga (Acacia aneura) was fed to five groups of four weaner wethers. One group was given a supplement of phosphorus (P) as NaH2PO4, another energy as molasses (E), a third both phosphorus and molasses (P + E) and the fourth urea, phosphorus and molasses (P + E + N) ; the fifth group acted as an unsupplemented control (C). Total dry matter intake during the 42 weeks of the experiment was progressively increased by the addition of P, E, P + E and P + E + N to the diet. Liveweight gain was highest inthe P + E + Ngroup followed by the P + Egroupandthen the E group. Groups P and C lost weight during the experiment. Balance studies showed that P + E and P + E + N supplementation enhanced nitrogen retention, and phosphorus supplementation increased phosphorus retention. The digestibility of mulga was increased by phosphorus supplementation. Specific gravity and phosphorus content per unit volume of bone were increased by supplementation with P + E + N and P + E, and phosphorus content was marginally increased by P supplementation.


1984 ◽  
Vol 64 (2) ◽  
pp. 403-410 ◽  
Author(s):  
G. E. McBRIDE ◽  
R. J. CHRISTOPHERSON

The performance and development of young Iambs housed at 0 ± 1 °C or 21 ± 1 °C were compared in two experiments. Despite similar nutrient intakes for both treatment groups, preweaning growth rate of the cold-exposed lambs tended to be reduced. Bone growth from 4 to 9 wk of age revealed a significant effect of temperature on metatarsal length (P < 0.05). By 10 wk of age morphological differences between the two groups were apparent, especially in terms of smaller ear dimensions (P < 0.01), head (P < 0.10) and metatarsal lengths (P < 0.05) of the cold-exposed lambs. Leg bone lengths after slaughter (13 wk of age) also tended to be shorter for the lambs housed at 0 °C. Organ weights measured after 11 wk of differential temperature exposure were similar for both groups except for slightly increased abomasal and thyroid weights (P < 0.10) in the cold-exposed group. Dry matter and nitrogen digestibilities of a concentrate ration fed to the weaned lambs were not affected by treatment, although nitrogen retention (g/day, g/g digestible N intake) was significantly lowered (P < 0.05) as a result of cold exposure. Key words: Cold, growth, digestion, morphology, lambs


1983 ◽  
Vol 37 (1) ◽  
pp. 105-112
Author(s):  
D. Levy ◽  
Z. Holzer ◽  
D. Drori ◽  
Y. Folman

ABSTRACTWheat straw treated with 35 g NaOH per kg was offered to male calves at three levels: 300 (A), 500 (B), and 700 (C) g/kg diet, in a metabolism trial and in a feeding trial. In the former the wheat straw was offered either neutralized with HC1 (N) or unneutralized (U), in six subtreatments (AN, BN, CN, AU, BU and CU) in a 3 × 2 factorial design to a total of 24 calves. Dry-matter intake per kg W0·73was 123, 108, 104, 122, 105 and 91 g/day, and the digestibility of the organic matter of the straw was 0·388, 0·616, 0·629, 0·385, 0·528 and 0·544 respectively. The apparent digestibility of the crude protein of the straw was negative. Nitrogen retention per kg W0·73was 0·91, 0·58, 0·52, 0·97, 0·57 and 0·50 g/day, respectively.In the feeding trial, unneutralized, NaOH-treated wheat straw was offered to a total of 84 calves for 100 days at the above three levels with two protein levels: standard, 120 g/kg (S) and high, 140 g/kg (H), in six subtreatments (AS, BS, CS, AH, BH and CH) in a 3 × 2 factorial design. The concentrates were pelleted. From day 101 to slaughter all the calves were offered one finishing diet.Level of protein had no effect on performance. Increasing the levels of straw in the first 100 days sharply reduced average daily gains; these were 1 074, 825 and 583 g, respectively. However, the respective average daily gains on the finishing diet were 1 131, 1 272 and 1 316 g, indicating a considerable amount of compensatory growth.


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.


2008 ◽  
Vol 88 (4) ◽  
pp. 693-701 ◽  
Author(s):  
M. Undi ◽  
C. Wilson ◽  
K. H. Ominski ◽  
K. M. Wittenberg

Four techniques were compared for their ability to estimate forage dry matter intake (DMI) of grazing animals. In the Cage technique, 10 grazing cages were placed within each pasture, and forage inside and outside the cages was clipped from 0.25-m2 quadrats after 12 to 20 d of grazing. The difference between forage inside and outside the grazing cage represented forage consumed by grazing animals. The second technique used n-alkane controlled release capsules to measure DMI of individual grazing animals (N-alkane marker technique). The remaining two techniques were prediction equations; one utilized body weight (BW) and average daily gain (ADG) to estimate DMI (Minson equation) and the other related dietary net energy concentration and BW to DMI (Net Energy equation). The four methodologies were applied to a 3-yr study evaluating liquid hog manure on the productivity of grass pastures. The study utilized steers of a relatively uniform body size on six continuously grazed grass pastures. When individual animal intakes were compared, the Net Energy equation estimated lower (P < 0.05) DMI than the Minson equation, with the N-alkane marker technique being intermediate. Dry matter intake (mean ± SD, kg d-1) was 5.3 ± 0.76, 7.4 ± 1.86, and 6.5 ± 2.58 for the Net Energy equation, Minson equation, and N-alkane marker technique, respectively. The Cage technique estimated average DMI of animals in each pasture of 17.5 ± 11.61 kg d-1 and this was higher (P < 0.05) than estimates from the other techniques. Dry matter intake estimates from different techniques were ranked: Cage technique > Minson equation > N-alkane marker technique > Net Energy equation. The DMI estimates generated by the Cage technique were associated with the largest coefficient of variation, with extreme values representing a range from 0.3 to 15.2% BW. The N-alkane marker technique estimated DMI that ranged from 0.6 to 4.5% BW. The strongest correlation (r = 0.30; P = 0.001) in DMI estimates was between the Net Energy and Minson equations due to the inclusion of BW as a component in both equations. Results of this study suggest that prediction equations can be useful for rapid DMI estimation. The N-alkane marker technique may be the preferred technique when a wide range of pasture conditions is anticipated. Key words: Grazing cages, n-alkanes, prediction equations, dry matter intake, grazing animals


2013 ◽  
Vol 53 (11) ◽  
pp. 1195 ◽  
Author(s):  
L. Li ◽  
C. I. Silveira ◽  
J. V. Nolan ◽  
I. R. Godwin ◽  
R. A. Leng ◽  
...  

The effects of dietary nitrate (NO3) and elemental sulfur (S) on nutrient utilisation, productivity, and methane emission of Merino lambs were investigated. Forty-four lambs were randomly allocated to four groups (n = 11) fed isonitrogenous and isoenergetic diets. The basal feed was supplemented with 1% urea + 0.18% S (T1), 1.88% NO3 + 0% S (T2), 1.88% NO3 + 0.18% S (T3), or 1.88% NO3 + 0.40% S (T4). Retention of S was improved by increasing the content of elemental S in the NO3-containing diet (P < 0.001), yet the N retention (g/day) by the animal, and the N and S content of wool (%), were not altered by S supplementation (P > 0.05). Dry matter intake, liveweight gain, and feed conversion ratio did not differ (P > 0.05) between treatments. Replacing urea with NO3 improved the rate of clean wool growth by 37% (P < 0.001, T1 vs T3). Clean wool growth increased by 26% (P < 0.001) when the S content of the NO3-containing diet was increased from 0 to 0.18% (T2 vs T3). Methane production (g/day) and methane yield (g/kg DM intake) were reduced (P < 0.05) by 24% when urea was replaced by NO3 (T1 vs T3). The addition of 0.4% S to a diet containing 1.88% NO3 also reduced methane production (P = 0.021) and methane yield (P = 0.028). In conclusion, the addition of 1.88% NO3 and 0.18% elemental S to a total mixed diet increased clean wool production and reduced methane production. However, there was no evidence of inter-relationships between NO3 and S.


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