Effects of soils, fertilizers and stocking rates on pastures and beef production on the Wallum of south-eastern Queensland. 2. Liveweight change and beef production

1973 ◽  
Vol 13 (64) ◽  
pp. 530 ◽  
Author(s):  
TR Evans ◽  
WW Bryan

Animal production was measured over a six-year period from grass-legume pastures receiving different maintenance rates of phosphorus and potassium fertilizers, and continuously grazed at stocking rates of 1.23, 1.65 and 2.47 beasts ha-1. The pastures consisted of the grasses Chloris gayana, Digitaria decumbens, Paspalum dilatatum and P. commersonii and the legumes Desmodium intortum, D. uncinatum, L otononis bainesii, Macrop tilium lath yroides and Trifolium repens. Annual applications of 250 kg ha-1 superphosphate (9.6 per cent P) significantly increased animal production above applications of 125 kg ha-1 superphosphate, but there were no significant effects of increase in level of applied potassium (as KCI) beyond 63 kg ha-1. The greatest liveweight gain per hectare was obtained at a stocking rate of 2.47 beasts ha-1 but rate of liveweight change was more variable than at the other stocking rates. Conversely, daily liveweight gains per head and rate of turnoff were greatest at 1.23 beasts ha-1. Both stocking rates and levels of superphosphate affected quality of carcase produced, and there was a significant positive correlation of liveweight gain and legume content of the pastures.

1973 ◽  
Vol 13 (64) ◽  
pp. 516 ◽  
Author(s):  
WW Bryan ◽  
TR Evans

A complex pasture mixture was grazed by cattle at three stocking rates (1.23, 1.65 and 2.47 beasts a hectare) at Beerwah, south-eastern Queensland over six years. There were four fertilizer treatments involving two rates of superphosphate and three of KCl. On the basis of species frequencies, the seven major soil types on the area fell into two groups, the podzolic soils in one and the humic gleys in another. The podzolics were favoured by Chloris gayana, Desmodium intortum, D. uncinatum and Lotononis bainesii, whereas Paspalum dilatatum and Trifolium repens were more frequent on the humic gleys. The light stocking rate favoured Paspalum commersonii, Digitaria decumbens and both Desmodium species. At the high stocking rate P. dilatatum, T. repens and L. bainesii were more prominent, as were weeds in general. Application of KCl had no effect on botanical composition but the K content of soils and plants increased with increasing levels of application. As the superphosphate rate was increased, the proportion of all sown species except P. dilatatum and L. bainesii increased and the weed content decreased. Over time, the legume content in all plots decreased, weeds increased and the grass content remained about the same. The effects were more marked at low rates of superphosphate and high stocking rate. There was a lower legume content and a higher weed content in winter than in summer, but soils and treatments had similar effects in both seasons. Compared with virgin soils, those under fertilized pastures for eight years contained more organic C, available P, K and Ca, total N, and Zn and Fe.


1977 ◽  
Vol 17 (85) ◽  
pp. 187 ◽  
Author(s):  
WH Winter ◽  
LA Edye ◽  
WT Williams

The animal production from two grass/legume pastures was measured over three years. The pastures were grazed at four stocking rates and annually received one of three maintenance rates of phosphorus fertilizer. The animals were given a phosphorus supplement at two rates. The grasses were either Brachiaria decumbens cv. Basilisk or Panicum maximum (common guinea grass) each sown with Stylosanthesguyanensis cv. Endeavour and Macroptilium atropurpureum cv. Siratro. The grasses had little effect on animal production although three Panicum pastures at higher stocking rates became overgrazed and required destocking during the experiment. Even though 73.5 kg ha-1 of phosphorus was used to establish the pastures, the maintenance rate of 40 kg ha-1 gave higher production than the 10 kg ha-1 rate in the first two years. In the third year, production was similar for each fertilizer rate. There was a concomitant rise in faecal phosphorus level with fertilizer rate but no such effect with blood inorganic phosphorus levels. Over the three years of the experiment the liveweight gain per hectare was similar (mean of 0.54 kg per day) at 1.7 and 1.9 beasts ha-1 but was significantly less at lighter stocking rates. In the last two years stocking rate did not significantly affect liveweight gain per head. At the highest stocking rate, gains were greater during the wet season and losses greater during the dry season than those at the lowest stocking rate. The phosphorus supplement did not affect animal production but increased blood inorgainc phosphorus levels. The relationships of animal production with blood and faecal compositions and with the pasture measurements described in a previous paper are discussed.


Author(s):  
K. Marsh ◽  
L.F.C. Brunswick

Lucerne and lucerne/prairie grass swards were compared at three stocking rates using yearling beef cattle. A 35 day rotational grazing system was used and the experiment ran for 130 days from early October, 1976. Pasture DM yields were higher on the mixed sward but animal production was greater on the lucerne only sward, particularly from December onwards. Increasing stocking rate tended to reduce herbage DM yield and per-animal production. There was no significant interaction between sward type and stocking rate on either sward or animal yield. Lucerne and lucerne/ prairie grass swards on pumice soil compared favourably with fertile Waikato permanent pastures in terms of carcass gain per hectare over the grazing period.


1968 ◽  
Vol 71 (3) ◽  
pp. 327-335 ◽  
Author(s):  
J. B. Owen ◽  
W. J. Ridgman

SUMMARYExperiments designed to assess differences between treatments in pasture productivity as measured by the production of animals are complicated by the stocking rates chosen. The paper attempts toderive a simple model relating production per animal and production per unit area to stocking rate for meat animals, based on biological considerations.A method is proposed which would allow meaningful grazing experiments to be carried out employing only one stocking rate, thus considerably reducing the expense of this type of experimentation.The model is applied to some recent data obtained by Hodgson (1966) and Appleton (1967, personal communication).


1983 ◽  
Vol 101 (1) ◽  
pp. 1-7 ◽  
Author(s):  
A. Pott ◽  
L. R. Humphreys

SUMMARYSheep were grazed for 2 years at stocking rates of 7, 14, 21 and 28/ha on a pasture comprising Lotononis bainesii and Digitaria decumbens cv. Pangola at Mt Cotton, south–east Queensland. There were six replicates of each treatment grazed in rotation with 3 days' grazing followed by 15 days' rest.The initial dominance of lotononis was lost after 6 months of grazing and lotononis failed to persist satisfactorily at any stocking rate. Demographic studies showed that lotononis behaved as a short-lived plant, predominantly annual, with some vegetative perennation as stolon-rooted units under heavy grazing. Soil seed reserves varied from 5800 to 400 m2 at the lightest and heaviest stocking rates respectively. Lotononis failed to regenerate under Pangola shading or inopportune high grazing pressure. Soil bulk density (0–7 cm) increased from 1·2 to 1·4 g/cm3 according to stocking rate.


1986 ◽  
Vol 8 (1) ◽  
pp. 46 ◽  
Author(s):  
RD Graetz

Measurements were made of the wool growth, body weight gain and diet of sheep grazing a saltbush pasture near Broken Hill, N.S.W. The experiment utilized a fenceline contrast in saltbush (Atriplex vesrcarra) density that was visible on Landsat imagery. It ran for five years (1976-1981) with a design of two pasture types by two stocking rates. Fleece weights varied from 3.9-6.0 kg/head and wool production from 0.6-2.9 kg/ha. Neither wool production per head nor bodyweight were substantially affected by stocking rate or pasture type. The composition and quality of the diets selected by sheep on both pastures were identical and of high nutritional value indicating their capability to accommodate differences in pasture composition. Pasture quality was not limiting between stocking rates or determined by the abundance of saltbush. Changes in pasture composition resulting from grazing and exclosure were small and of no significance.


1993 ◽  
Vol 33 (5) ◽  
pp. 561 ◽  
Author(s):  
CJ Gardener ◽  
MR McCaskill ◽  
JG McIvor

Native pastures dominated by Heteropogon contortus (speargrass) were sown to Stylosanthes hanzata cv. Verano in 1972, and herbage production and steer growth rates were compared with those of native pastures from 1973 to 1985. The native pastures also contained naturalised Stylosanthes humilis, but its contribution to pasture yield diminished rapidly, after infection by Colletotrichum gloeospoirioides (anthracnose) in 1973. The experiment was a factorial design of 2 pasture types (native, native plus Verano) x 2 stocking rates (0.6, 1.2 steers/ha) x 2 superphosphate treatments (nil, 300 kg/ha.year) x 2 replicates. Fertiliser application decreased the proportion of legume but had no significant effect on herbage or animal production on this comparatively fertile site (extractable P, 18 mg/kg). Annual liveweight gains at the high and low stocking rates, respectively, on the native pasture averaged 100 and 120 kg/steer. Sowing to Verano did not affect herbage yields but increased annual liveweight gains by 28 and 36 kg/steer at low and high stocking rates. The high stocking rate of 1.2 steers/ha was sustainable for the first 9 years of the experiment, when above-average rainfall was received. However, in the following 3 below-average years, there was a shift to less-desirable species, and a decline in pasture productivity. Relative to the low stocking rate, herbage production on the native pasture in the final season was reduced by 60% and on the Verano pasture by 26%. The highest annual herbage utilisation rate that appeared sustainable in the long term was about 45%, which corresponded to a utilisation rate of 30% during the growing season (about November-May). When oversown with Verano, speargrass tended to decline in favour of annual grasses, weeds, and the introduced grass Urochloa mosanzhicensis, which had been sown on an adjacent experiment. Urochloa appeared to be a more suitable companion species than speargrass for Verano.


1976 ◽  
Vol 27 (6) ◽  
pp. 881 ◽  
Author(s):  
JG Mulholland ◽  
JB Coombe ◽  
M Freer ◽  
WR McManus

The production of young crossbred wethers grazing oat, barley and wheat stubbles was measured in each of three years at stocking rates ranging from 15 to 30/ha. In one year, production on 'weedy' stubbles was compared with that of 'clean' (weed-free) stubbles, and also the effect of a wheat–urea–mineral supplement on the production of sheep was measured on oat stubble. Liveweight change and wool production were significantly influenced by the availability of green plant material and by stocking rate, but not by supplementation. The maximum liveweight loss in any year was 7.5 kg and the maximum gain 6.0 kg, both recorded over 11 weeks' grazing. Mean daily clean wool production was 9.9 g/sheep at the lower stocking rate and 6.6 g/sheep at the higher rate, but production per hectare was 10–60% higher at the heavier stocking rate. The ranking of the crop stubbles with respect to animal production was not consistent from year to year. Intense selection for green plant material by sheep resulted in the proportion of green in the diet being nearly always greater than 80%, when the weight of this material on the plots was more than 40 kg dry matter/ha. It appeared that a low intake of nitrogen was not the main limitation to animal production. A maximum of only 36% of the crop residue which disappeared during the experiment could be accounted for as animal intake. Thus it is unlikely that the potential of cereal residues as a source of food for animal production will be realized with grazing sheep.


1959 ◽  
Vol 10 (2) ◽  
pp. 248 ◽  
Author(s):  
WM Willoughby

An experiment with Merino wethers on a Phalaris tuberosa-subterraneum clover-volunteer grass pasture has compared throughout an annual cycle the effects of: (a) Seasonal fluctuations in quantity and quality of pasture on liveweight gains and wool production in sheep. (b) Different grazing systems at equal stocking rates both on pasture growth and on liveweight and wool production in sheep. (a) Availability of dry pasture did not affect animal production so long as green pasture was present. Small increases in green pasture in the period of slow growth (winter) gave large increases in liveweight and wool production. Large increases in green pasture in the period of rapid growth (spring) had no effect on the animal. On dry pasture (summer) heavy sheep lost more weight than light sheep. Increasing the amount of dry pasture reduced liveweight loss only slightly but resulted in a greater rate of breakdown of plant material. An asymptotic relationship between availability of green pasture aid animal gain is presented, the asymptote in this instance occurring at a,pproxirnatnly 1400 lb dry matter per acre. The implications of the results are discussed with reference to methods of investigation of species, fertilizers, end management procedures aimed at 01-ercoming pasture limitations to animal production. The validity of investigations which do not take into account the relative constancy of grazing pressure throughout the year, and the continuing effects of plant on animal and animal on plant, is questioned. (b) Regardless of the degree to which pastures had been checked by grazing in spring, all dried out simultaneously on the onset of summer, and all sheep on all treatments reached their peak liveweight turning point on approximately the same date. Less than one-third of the liveweight gain potential of the pasture was attained on any one of the three grazing systems. The mean amounts of the individual pasture components, and of the total weight of pasture, were identical at any one time under the three grazing systems. The closer the systems approached towards continuous grazing the greater were the liveweight gains and wool production.


1983 ◽  
Vol 23 (123) ◽  
pp. 383 ◽  
Author(s):  
DL Lloyd ◽  
JG Nation ◽  
TB Hilder ◽  
PK O'Rourke

Three Makarikari grasses (Panicum coloratum var. makarikariense) viz. 0.4634, cv. Pollock and cv. Bambatsi and Rhodes grass (Chloris gayana) cv. Pioneer, each grown with lucerne (Medicago sativa) cv. Hunter River, and sward lucerne were compared for productivity and stability in a rotational grazing system at three stocking rates (22.2, 14.8 and 7 . 4 Merino wethers/ha for grasslucerne pastures; 14.8, 11.1 and 7.4/ha for lucerne swards) on a cracking clay soil on the Darling Downs, Queensland over four years. There were no differences between the Makarikari grass cvv. Pollock and Bambatsi pastures. However, each produced more dry matter and animal liveweight, and persisted better, than Rhodes grass pasture during dry conditions that occurred during the first two years. Rhodes grass nevertheless recovered during two subsequent wet summers. During those two dry years, wool production from sward lucerne was equal to that of the grass-lucerne pastures at both 14.8 and 7.4 animals/ha. Animal liveweight from lucerne was greater than from grass-lucerne pastures at 7.4 animals/ha only. Wide variation, both between and within seasons, was measured in the quantity of feed produced by pastures in this study. This is discussed in relation to the concept of stocking rate of pasture grown on limited areas of grain farms in the northern wheat belt, and to the provision of a continuing feed supply in integrated crop-pasture systems.


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