Effects of fertilizer and stocking rate on pasture and beef production from sown pastures in north Cape York Peninsula. 2. Beef production and its relation to blood, faecal and pasture measurements

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.

1977 ◽  
Vol 17 (84) ◽  
pp. 66 ◽  
Author(s):  
WH Winter ◽  
LA Edye ◽  
RG Megarrity ◽  
WT Williams

The seasonal changes in the yield, botanical composition and chemical composition (nitrogen, phosphorus and sulphur) of the pasture plants were measured in a grazing experiment over three years. The 48 treatments were factorial combinations of two different grasses with a common legume mixture, three annual maintenance rates of phosphorus fertilizer, four stocking rates of continuous grazing and two rates of phosphorus fed directly to the cattle. The pastures consisted of Brachiaria decumbens cv. Basilisk or Panicum maximum (common guinea grass) sown with Stylosanthes guyanensis cv. Endeavour and Macroptilium atropurpureum cv. Siratro. Brachiaria decumbens was more persistent than Panicum maximum when heavily stocked at low fertilizer phosphorus rates and in the latter half of each wet season the legume content of the Brachiaria pastures was lower. Of the two grasses, Panicum maximum contained the higher N, P and S contents. In the third year 20 kg ha-1 of phosphorus gave higher yields than 10 kg ha-1 without affecting the chemical or botanical composition of the pastures but 40 kg ha-1 decreased the legume content of the pastures and raised the phosphorus levels in stylo. Pasture yield decreased with increasing stocking rate with only minor effects on the botanical composition of the pastures. However, there was a concomitant increase in pasture quality, particularly in phosphorus content, with increasing stocking rate.


1978 ◽  
Vol 29 (1) ◽  
pp. 103 ◽  
Author(s):  
LA Edye ◽  
WT Williams ◽  
WH Winter

The relationship between stocking rate and liveweight change per animal was examined over a period of 3 years for two continuously grazed pastures, one of Brachiaria and the other consisting of guinea grass with Endeavour stylo and Siratro. On an annual basis there was no significant effect of stocking rate over the last 2 years, but on a seasonal basis there were highly significant effects in all seasons. In the dry seasons, animal gain rose as the stocking rate fell, but in the last two wet seasons gains fell with the lower stocking rates. On an annual basis the two effects cancelled out. Response surfaces for gain versus pasture yield and stocking rate were curvilinear (quadratic) during the wet season and linear during the dry. Optimum stocking rates (for maximum gain per hectare) were determined for the wet and dry seasons; the rate was greatly affected by the yield of green material during the dry season but less so during the wet. The possible causes of this reversed wetseason effect 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.


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.


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).


1973 ◽  
Vol 13 (64) ◽  
pp. 537 ◽  
Author(s):  
RF Thornton ◽  
DJ Minson

During the concluding phase of a six-year grazing trial a study was made of the steers and the pasture material from paddocks annually fertilized with 125 kg ha-1and 250 kg ha-1of superphosphate. Plucked pasture samples from the low and high superphosphate treatments contained 0.11 and 0.15 per cent phosphorus, 0.83 and 0.91 per cent nitrogen and 0.12 and 0.12 per cent sulphur, respectively. The N: S ratio of these samples were 6.8 and 7.6 and the in vitro digestibilities were 41.6 and 44.9 per cent. There were marked seasonal patterns in the concentrations of all components with minimum values in the winter months when liveweight gain was lowest. Greater superphosphate application increased mean liveweight gain (0.29 to 0.41 kg head-1day-1), mean plasma concentrations of both urea-nitrogen (6.3 vs 5.0 mg 100 ml-1) and of inorganic phosphorus (6.7 vs 6.3 mg 100 ml-1). The mean blood sulphate-sulphur concentration of 28 �g ml-I was not influenced by treatment. Comparisons of the levels of nutrients in pasture and blood with published requirements indicated that neither sulphur nor phosphorus were deficient in either treatment. However, the between treatment differences in both nitrogen and phosphorus levels could not be ignored as possible reasons for the difference in animal production between the two levels of superphosphate application. Improved animal performance associated with increased application of superphosphate was probably influenced more by the induced changes in the organic components rather than the mineral levels of the pasture material.


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.


1967 ◽  
Vol 69 (2) ◽  
pp. 155-160 ◽  
Author(s):  
W. L. Johnson ◽  
W. A. Hardison ◽  
L. S. Castillo

The results of more than fifty estimates1 of herbage yield and ninety-seven analyses of chemical composition are presented in the first of several reports on nutritive evaluation studies of Panicum maximum (guinea grass). Effects of stage of maturity and season are discussed.Herbage yield increased at an increasing rate with maturity, and was depressed by about 40 % in the dry season compared to the wet season. The most significant differences in chemical composition were a decrease in crude protein from 9·8 % to 6·6% and a corresponding increase in crude fibre from 32·1 % to 39·4% as the grass matured from about 2½ weeks to about 2½ months in age. An increased level of nitrogen fertilization resulted in crude protein content being nearly doubled and crude fibre somewhat reduced.


2020 ◽  
Vol 12 (1) ◽  
pp. 3-14 ◽  
Author(s):  
D. H. Cobon ◽  
R. Darbyshire ◽  
J. Crean ◽  
S. Kodur ◽  
M. Simpson ◽  
...  

AbstractSeasonal climate forecasts (SCFs) provide opportunities for pastoralists to align production decisions to climatic conditions, as SCFs offer economic value by increasing certainty about future climatic states at decision-making time. Insufficient evidence about the economic value of SCFs was identified as a major factor limiting adoption of SCFs in Australia and abroad. This study examines the value of SCFs to beef production system management in northern Australia by adopting a theoretical probabilistic climate forecast system. Stocking rate decisions in October, before the onset of the wet season, were identified by industry as a key climate sensitive decision. The analysis considered SCF value across economic drivers (steer price in October) and environmental drivers (October pasture availability). A range in forecast value was found ($0–$14 per head) dependent on pasture availability, beef price, and SCF skill. Skillful forecasts of future climate conditions offered little value with medium or high pasture availability, as in these circumstances pastures were rarely overutilized. In contrast, low pasture availability provided conditions for alternative optimal stocking rates and for SCFs to be valuable. Optimal stocking rates under low pasture availability varied the most with climate state (i.e., wet or dry), indicating that producers have more to gain from a skillful SCF at these times. Although the level of pasture availability in October was the major determinant of stocking rate decisions, beef price settings were also found to be important. This analysis provides insights into the potential value of SCFs to extensive beef enterprises and can be used by pastoralists to evaluate the cost benefit of using a SCF in annual management.


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