A relation between wool production per animal and annual pasture dry matter production per animal

1982 ◽  
Vol 33 (4) ◽  
pp. 705 ◽  
Author(s):  
BA Rowe

A simple relation between the annual wool production per animal (y) and the amount of pasture dry matter produced per animal (x) was derived and tested using the results from a grazing experiment in which the effects of superphosphate and stocking rate on wool and pasture dry matter production were measured from pastures which were continuously grazed by Merino wethers for 3 years. The linear relation, y = a + b/x, accounted for 63% of the variance in wool production per animal in the first year, 82 % in the second and 97 % in the third. Exclusion of an outlier from the first year results increased the variance accounted for to 85 %. This model is simpler and more precise than some others that have been published. It is also consistent with the curvilinear relation between production per animal (y) and pasture production per animal (x).

1966 ◽  
Vol 67 (2) ◽  
pp. 199-210 ◽  
Author(s):  
A.G. Campbell

1. Net pasture dry matter production and available pasture dry matter were measured over 3 years in a small-scale replica of the study of the effects of dairy cow grazing management and stocking rate reported by McMeekan & Walshe (1963).2. The four treatments were(i) Controlled rotational grazing, light stocking rate (0.95 cows/acre).(ii) Controlled rotational grazing, heavy stocking rate (1.19 cows/acre).(iii) Uncontrolled, set stocked grazing, light stocking rate (0.95 cows/acre).(iv) Uncontrolled, set stocked grazing, heavy stocking rate (1.19 cows/acre).3. The pasture measurement technique employed measured net pasture production (gains through new growth minus losses from all sources). It is argued that this parameter, rather than absolute pasture production, governs the changes in the dry matter feed supply to the grazing animal.


Author(s):  
R.T. Alexander

Persistency and productivity of irrigated 'Grasslands Matua' prairie grass pastures were measured under four sheep grazing regimes, frequent or infrequent (grazed 3 weekly or 6 weekly) coupled with lax or severe defoliation (grazed to 7.5 cm or 2.5 cm). Matua was also compared with 'Grasslands Nui' and Yates 'Ellett' perennial ryegrasses under frequent severe grazing. These are interim results from two experiments sown in successive years. There were few consistent differences among grazing treatments of Matua pastures. However, the Matua content of pastures tended to be less under frequent grazing. In the third year of Experiment 1, infrequent grazing to 2.5 cm resulted in significantly hlgher annual production than other Matua treatments. 'Eiiett' ryegrass tended to outyield 'Grasslands Nui' in the first year but subsequently there was little difference in yields. The dry matter production of 'Ellett ryegrass was not significantly different from the best Matua treatment in any year. More herbage was lost through trampling and decay in the infrequently grazed Matua pastures than in the frequently grazed Matua or ryegrass pastures. After three years, all Matua pastures contained more weeds and more volunteer grasses than did ryegrass pastures. Keywords: prairie grass, Matua, ryegrass, Nul, Ellett, grazing management, lax grazing, severe grazing, irrigation.


2010 ◽  
Vol 61 (5) ◽  
pp. 353 ◽  
Author(s):  
L. L. Burkitt ◽  
D. J. Donaghy ◽  
P. J. Smethurst

Pasture is the cheapest source of feed for dairy cows, therefore, dairy pastures in Australia are intensively managed to maximise milk production and profits. Although soil testing commonly suggests that soils used for dairy pasture production have adequate supplies of phosphorus (P), many Australian dairy farmers still apply fertiliser P, often by applying smaller rates more frequently throughout the year. This study was designed to test the hypotheses that more frequent, but lower rates of P fertiliser applied strategically throughout the growing season have no effect on dry matter production and P concentration in perennial ryegrass (Lolium perenne L.), when soil extractable P concentrations are above the critical value reported in the literature. Three field sites were established on rain-fed dairy pasture soils ranging in P sorption capacity and with adequate soil P concentrations for maximising pasture production. Results showed that applied P fertiliser had no effect on pasture production across the 3 sites (P > 0.05), regardless of rate or the season in which the P was applied, confirming that no P fertiliser is required when soil extractable P concentrations are adequate. This finding challenges the viability of the current industry practice. In addition, applying P fertiliser as a single annual application in summer did not compromise pasture production at any of the 3 sites (P > 0.05), which supports the current environmental recommendations of applying P during drier conditions, when the risk of surface P runoff is generally lower. The current results also demonstrate that the short-term cessation of P fertiliser application may be a viable management option, as a minimal reduction in pasture production was measured over the experimental period.


1995 ◽  
Vol 46 (7) ◽  
pp. 1401 ◽  
Author(s):  
RR Gault ◽  
MB Peoples ◽  
GL Turner ◽  
DM Lilley ◽  
J Brockwell ◽  
...  

Nodulation, N2 fixation (estimated by 15N natural abundance methods) and dry matter production were studied in a lucerne (Medicago sativa) crop managed for hay production at Ginninderra Experiment Station, A.C .T. Measurements were taken in the year of establishment and during two subsequent growing seasons. There were three treatments: (1) no inoculation and no annual fertilizer applied, (2) initial inoculation and superphosphate applied annually, (3) no inoculation, superphosphate applied annually and ammonium sulfate periodically. Before planting and after each growth season, soil was analysed for extractable mineral nitrogen, total nitrogen and the 15N natural abundance of this nitrogen, to the depth explored by lucerne roots. Before planting, no appropriate root-nodule bacteria (Rhizobium meliloti) were detected in the soil and initially plants were nodulated only in the inoculated treatment. Thereafter nodulation increased on the other treatments. Eight months after sowing there were no differences between treatments in numbers of R. meliloti g-l soil or in nodulation. In the third growing season, almost 30 kg ha-1 (dry wt) of nodules were recovered to a depth of 25 cm. These nodules were primarily located on fine, ephemeral roots and many appeared to be renewed after cutting of the lucerne. In the year of establishment, dry matter yields (0% moisture) totalled 3 to 4 t ha-1 in three hay cuts. In succeeding years, total yields were in the range 10 to 13 t ha-1 in four or five cuts per season. Nitrogen removed in the harvested lucerne reached 340 to 410 kg N ha-lyr-l in the second and third years and between 65 and 96% of this N arose from N2 fixation, depending on the method of calculation used. Poorer dry matter production and N2 fixation in treatment 1 in the third growing season was attributed to an insufficient supply of available phosphorus. Fixed N removed in Lucerne hay from treatment 2 totalled at least 640 kg N ha-1 in the three years of the experiment. Also, there were substantial increases in soil nitrogen due to lucerne growth. Although soil compaction made the quantification difficult, at the end of the experiment it was estimated that there was at least an extra 800 kg N ha-1 in the total soil nitrogen under lucerne compared to strips of Phalaris aquatica grown between the lucerne plots. It was concluded that lucerne contributed at least the same amount of fixed nitrogen to the soil as was being removed in the harvested hay.


1997 ◽  
Vol 37 (2) ◽  
pp. 165 ◽  
Author(s):  
J. S. Dunbabin ◽  
I. H. Hume ◽  
M. E. Ireson

Summary. Perennial ryegrass–white clover swards were irrigated for 3 years every 50, 80 and 120 mm of crop evapotranspiration minus rainfall (ETc–R) and water ponded on the soil surface for either 4, 12 or 24 h at each irrigation. Pasture production and clover content were highly seasonal, peaking in spring and autumn. Frequent irrigation increased dry matter production by an average of 56%. When irrigating at 50 mm ETc–R, dry matter production was decreased by ponding water on plots, 17% for 12 h ponding and 14% if ponded for 24 h. However, when irrigating at an interval of 80 mm ETc–R ponding increased dry matter production by 7% for 12 h ponding and by 25% for 24 h ponding. Ponding also increased production at an irrigation interval of 120 mm ETc–R by 25% for 12 h ponding but only by 2.4% for 24 h ponding. While these increases in dry matter production are large in relative terms the absolute increase in production is small. More water infiltrated per irrigation at longer irrigation intervals, and at longer ponding times. Frequently irrigated, rapidly drained swards used irrigation water most efficiently. The small gain in dry matter production achieved by prolonging ponding at longer irrigation intervals is an inefficient use of water and likely to recharge regional groundwater systems. Oxygen diffusion rate measurements suggested that ponding for as short as 4 h was likely to cause waterlogging stresses and that these stresses were higher when irrigating frequently. The relative increase in waterlogging stress by extending the period of ponding from 4 to 24 h was small.


2004 ◽  
Vol 44 (2) ◽  
pp. 151 ◽  
Author(s):  
M. Bethune ◽  
Q. J. Wang

The dairy industry is a major user of water in northern Victoria and southern New South Wales. Water is typically applied to pasture using the border-check irrigation system. The border-check system is largely gravity driven and thus energy efficient. However, deep drainage can potentially be high because the system allows only limited control over the depth of water applied in each irrigation event. For this reason, heavy soils are regarded as the most suitable for border-check irrigation. This study quantified net deep drainage (deep drainage less capillary rise) under border-check irrigated pasture on a Goulburn clay loam soil. Additionally, the study investigated the extent to which irrigation frequency and watertable conditions influence water use, dry matter production and deep drainage. The water balance and dry matter production were monitored over 2.5 years in a lysimeter facility in northern Victoria. The Goulburn clay loam is representative of the heavier textured soils used for border-check irrigation of pasture in northern Victoria. The average measured net deep drainage was 4 mm/year. This indicates that relatively small levels of net deep drainage can be achieved under well-managed border-check irrigation on a Goulburn clay loam soil. Net deep drainage losses were greatest following winter, when rainfall exceeded pasture water use for an extended period. Increasing the interval between irrigation events resulted in reduced plant water use, infiltration of irrigation water, rainfall runoff and pasture production. However, increasing the interval did not impact on net deep drainage or water use efficiency. Depth of watertable had a relatively minor impact on the water balance.


Author(s):  
I.P.M. Mcqueen ◽  
J.A. Baars

Dry matter production data for pure lucerne, overdrilled lucerne and pasture are presented for 14 sites on pumice soils. On average, the annual dry matter yield of lucerne, harvested at early basal shoot movement, was 50% higher than from pasture, ranging from 128% higher on a drought-prone soil where the pasture was dominant browntop to 33% on a more moisture-retentive soil type where the pasture was ryegrass dominant. From April until late October there was little difference in total dry matter between lucerne and pasture, although pasture had a .more even distribution of usable production than lucerne 'managed for maximum yield. Attempts to fill the winter/spring gap in lucerne production through introducing grasses and cereals have met with variable success. It is suggested that, on the more moisture-retentive soils, pasture production could be improved through grazing management and the use of more drought-resistant cultivars. Such an approach may meet the feed demands of animals more closely than an increasing dependence on lucerne with its specific management requirements.


1975 ◽  
Vol 55 (3) ◽  
pp. 711-725
Author(s):  
J. L. DIONNE ◽  
G. LALANDE ◽  
J. GENEST ◽  
C. FERNET

The influence of chemical fertilizers, stocking rate and meal supplementation on herbage and beef production was determined in a 3-yr pasture experiment. A stocking rate of 2.47 heads/ha was compared to one of 4.94 heads/ha. At the latter stocking rate, some of the steers were fed meal while on pasture. The fertilizer rates used were 1,121, 2,242 and 3,363 kg/ha of 10–10–10. All factors were combined in a factorial way. The fertility level of the soils was increased due to chemical fertilizer applications and at the highest rate, an excessive buildup of K occurred in soils. Phosphorus and potassium levels in soils were also increased at the highest stocking rate. An increase in fertilizer rate increased the total dry matter production of the herbage by 28%. Most of the increase in dry matter yields was accounted for by the harvesting of herbage surpluses obtained on the pastures fertilized with the highest rate of 10–10–10 and where the stocking rate was 2.47 heads/ha. At the stocking rate of 4.94 heads/ha, it was impossible to maintain the pasture dry matter production to meet the feed requirements of the grazing steers during the complete pasture season, even when the highest fertilizer rate was used. In the second half of the season, the daily body weight gains of the steers decreased by 50%. Feeding meal to the steers from mid-August compensated for the herbage shortage. The growth rate was markedly increased, while the carcasses had a thicker fat cover and a larger eye of lean. Finishing steers on grass pastures exclusively was possible at the stocking rate of 2.47 heads/ha. The maximum fertilizer rate appears to be at 200 kg/ha of each of N, P2O5 and K2O. The optimum rate would be half of this quantity.


Author(s):  
R.J. Johnson ◽  
N.A. Thomson ◽  
D.A. Mccallum ◽  
T.G. Judd

Seasonal and annual dry matter production of ryegrass was compared with drought- and grass grub-tolerant species Grasslands Roa tall fescue (Festuca arundinacea Schreb.), Grasslands Maru phalaris (Phalaris aquatica L.) and Grasslands Kara cocksfoot (Dactylis glomerata L.) as both single species and different combinations of mixes in two trials from 1982 to 1991. In trial 1, Nui ryegrass (damaged by Argentine stem weevil) produced significantly less than cocksfoot, phalaris and mixtures of the drought-tolerant grasses. Yatsyn-1 ryegrass in trial 2 was not subjected to stem weevil attack and the annual dry matter production was significantly higher than that of tall fescue and, although not significantly, higher than that of phalaris and cocksfoot. In both trials the highest producing mixture was the phalaris/ cocksfoot mix with the exception of the triple mix of phalaris/cocksfoot/tall fescue in trial 2. The phalaris/cocksfoot mix produced significantly more than phalaris as a single species and although not significant, 14% more than cocksfoot suggesting these species are complementary in a mix. The triple mix in trial 2 produced significantly more than all single species except ryegrass. Mixes of srgnificant. tall fescue/phalaris and tall fescue/cocksfoot had no advantage in DM production over single-species sowings of phalaris or cocksfoot, but improved yields over tall fescue. These results show possible complementary effects to sowing phalaris and cocksfoot. The addition of tall fescue to the mix had small and non-significant benefits. Keywords: Dactylis glomerata, Festuca arundinacea, Loliumperenne, Phalaris aquatica. grass grub, pasture mixes, pasture production, single species, summer dry spells


Author(s):  
R.B. Allen ◽  
I.R. Mcdonald ◽  
N.A. Cullen

White clover (Trifolium repens), red clover (T. pratense), subtcrrnnean clover (T. subterraneum) and alsike clover (T. hybridum) were sown singly or in combinations at three sites in Otago. Ryegrass (Lolium perenne) was included in all clover treatments and was also sown alone. Lucerne (Medicago sativa) was sown alone at two sites. Herbage dry matter production was measured over a three-year period. At the high fertility lnvermay site, white and red clovers gave similar total and legume dry matter production and were markedly superior to alsike and subterranean clovers. White and nlsike clovers were most productive at the higher altitude, low fertility Berwick site, and at the dry, medium fertility Dunback site red clover produced the highest yields. Lucerne greatly outyielded all other species in the second and third years at Invermay and in the third year at Dunback.


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