Fertility and seasonal changes in liveweight of Droughtmaster cows grazing a Townsville stylo-spear grass pasture

1971 ◽  
Vol 22 (6) ◽  
pp. 963 ◽  
Author(s):  
LA Edye ◽  
JB Ritson ◽  
KP Haydock ◽  
Davies J Griffiths

An experiment was conducted to examine the fertility and seasonal changes in liveweight of cows grazing a Townsville stylo–spear grass pasture for over 4 years. There were two replicates of 12 treatments, which were factorial combinations of two stocking rates and three levels of superphosphate with and without conservation of hay. All experimental factors influenced cow liveweight. Cows on the pastures receiving superphosphate were heavier throughout the experiment than cows on unfertilized (F0) pasture; in most years there was little difference between pastures receiving superphosphate at 377 kg/ha (F3) and 126 kg/ha per year (F1). Stocking rate and conservation of hay had smaller but significant effects throughout the experiment. There were also marked seasonal fluctuations in cow liveweight associated with the amount and distribution of rainfall. Superphosphate was the only treatment that significantly affected conception and calving rate (F3 > F1, F0 at P < 0.01). Numerical analyses published elsewhere of average cow liveweight before and after mating and of conception rate strongly indicated a direct effect of superphosphate on conception rate that could not be explained by liveweight differences. This effect was primarily associated with the highest rate of superphosphate (F3), the F1 effect being more equivocal. There were significant differences between the three rates of superphosphate in the rate of change of cow liveweight during the first lactation (F3 > F1 > F0 at P < 0.05) but the differences appeared inadequate to influence conception rate markedly. Without fodder conservation, 1 cow unit to 2.4 ha was a safe stocking rate for fertilized pastures. This is three to four times the carrying capacity of unimproved spear grass pastures in the region.

2014 ◽  
Vol 54 (10) ◽  
pp. 1694 ◽  
Author(s):  
S. M. Robertson ◽  
A. F. Southwell ◽  
M. A. Friend

Month of joining and lamb sale strategy influence both the quantity and so value of lamb produced, and the feed required, so are important management decisions contributing to the profitability of sheep systems. Simulation modelling was used to evaluate the impact on gross margins of three lamb sale strategies for different months of joining and varying stocking rates. A flock of purchased Merino ewes producing crossbred lambs in southern Australia was modelled between 1971 and 2011. April joining produced higher gross margins than November or January only if the number of ewes per hectare was increased to potential carrying capacity. At the optimum stocking rate for each month of joining, three sale policies – a flexible lamb sale policy (where lambs were sold depending on seasonal conditions); selling lambs in December; or selling at 45-kg liveweight, all produced a similar mean gross margin, but the feed resources required were least using the flexible strategy (April-joined mean 195 ± 253 s.d. kg/ha for flexible compared with 219 ± 270 kg/ha if selling December or 1085 ± 459 kg/ha if sold at 45 kg). Mean gross margin differed between sale strategies by up to AU$66/ha if the optimal stocking rate was not used. These results suggest that the most advantageous lamb sale strategy will vary with both month of joining and stocking rate used, and should be considered when optimising sheep management systems.


1970 ◽  
Vol 11 ◽  
pp. 63-70
Author(s):  
NR Devkota ◽  
MR Kolachhapati

A study of the representing rangelands of Taplejung district was carried out during summer of 2009 to estimate the herbage mass yield of different slope categories, and to calculate the carrying capacity (CC) of the representing rangelands based on 60 days re-growth period so that optimum number of livestock unit (LU) per unit area would be possible to allow for grazing. The findings revealed that plain slope had higher herbage mass produced, but was comparatively over-grazed as revealed by higher stocking rate. Existing carrying capacity reasonably supports the grazers, but irrespective of the quality herbage. In deed there was a lower CC for higher slope area with higher CC for plain slope. Nevertheless, the CC values for different slope categories indicated that rangelands in Taplejung district has wider scope of improvement, both for herbage mass productivity, and grazing management through precise stocking rates to match with the prevailing carrying capacity. A major challenge, however, lies to convince herders about the benefits of reducing stocking rates and improving production efficiencies, with the increased income and less degradation of the present available rangelands. Detail study on herbage mass production based on total herbage mass harvest days of a year along with stocking rate for the respective period would be important to consider in generating concrete and site specific information. Key words: herbage mass; carrying capacity; stocking rate; rangelands; herders; Taplejung district DOI: 10.3126/njst.v11i0.4125Nepal Journal of Science and Technology 11 (2010) 63-70


2018 ◽  
Vol 53 (9) ◽  
pp. 1053-1060 ◽  
Author(s):  
Arielle Elias Arantes ◽  
Victor Rezende de Moreira Couto ◽  
Edson Eyji Sano ◽  
Laerte Guimarães Ferreira

Abstract: The objective of this work was to evaluate the potential of livestock intensification in Brazil. Beef cattle stocking rates were estimated according to agricultural census data on livestock production in Brazilian municipalities. Pasture carrying capacity was obtained by combining moderate resolution imaging spectroradiometer (Modis) images of gross primary productivity and data on dry matter demand per animal unit (AU). Cattle stocking rate for Brazil, in 2014/2015, was 0.97 AU ha-1, and the carrying capacity was 3.60 AU ha-1; therefore, there is an average livestock intensification potential of 2.63 AU ha-1. The highest average intensification potential was observed for the Southern region (3.62 AU ha-1), and the lowest for the Northern (2.13 AU ha-1) and Northeastern regions (2.22 AU ha-1). It is possible to estimate cattle stocking rate, pasture carrying capacity, and potential of livestock intensification by integrating data on agricultural census and remote sensing.


2007 ◽  
Vol 29 (2) ◽  
pp. 139 ◽  
Author(s):  
R. B. Hacker ◽  
W. J. Smith

Long-term data for (simulated) daily pasture growth and moving 12-monthly rainfall totals were used to examine the performance of the DDH/100 mm stocking rate index under theoretically ideal management for three locations in the Western Division of NSW. Stocking rate was adjusted either monthly or biannually based on rolling 12-monthly values for either pasture growth or rainfall. Under these ‘ideal’ conditions, monthly values of the index fluctuated widely around the carrying capacity benchmark. In practice, such comparisons would not provide a reliable assessment of the sustainability of the current stocking rate or of the need to adjust stock number to match seasonal conditions. Stocking rates calculated from pasture growth estimates were similar to those derived simply from rainfall and the carrying capacity benchmark, and produced similar levels of pasture utilisation. This ‘benchmark method’ of stocking rate determination thus provides a readily calculated, dynamic benchmark against which actual stocking rate may be compared. Due to lag effects, application of calculated proper stocking rates may lead to excessive pasture utilisation under low rainfall conditions (12-monthly totals less than 120–150 mm for the locations studied or, as a rule of thumb, the 10th percentile). Continuous paddock monitoring and projection of 12-monthly rainfall totals are therefore essential components of sustainable management. Short-term trends in the stocking rate index, driven by rainfall at constant stocking rate, will not provide any generally reliable indication of impending dry spells or feed deficits.


Author(s):  
P.G. Yeoman

The evidence available on pasture production in the King Country is reviewed and compared with stock requirements. A potential carrying capacity of 19 stock units/ha in the Waitomo County is estimated. It is shown that, when product prices are high, the economic optimum stocking rate is near the point beyond which stock will be seriously underfed. Management techniques aimed at producing and utilizing pasture feed efficiently and also allowing flexibility in stocking rates to meet varying economic conditions are outlined.


1971 ◽  
Vol 22 (6) ◽  
pp. 993 ◽  
Author(s):  
JB Ritson ◽  
LA Edye ◽  
PJ Robinson

A previously described experiment designed to study the effect of stocking rate, superphosphate, and conservation of hay on the fertility of cows had shown that only superphosphate significantly increased the conception rate. The present paper discusses the nutritional adequacy of the pastures for breeding cows. All experimental factors significantly influenced yield and botanical composition. Pastures at the lower of two stocking rates remained dominated by perennial grasses while those at the higher rate became dominated by Townsville stylo and annual grasses. Conservation of hay increased annual species, and superphosphate increased Townsville stylo in lightly grazed pastures. Pasture yield was adequate at the lower stocking rate but became limiting at the higher rate. Superphosphate increased pasture yields during the third and fourth year. Superphosphate increased the phosphorus and sulphur contents of the three major components —Townsville stylo, perennial grasses, and annual grasses, the nitrogen content of Townsville stylo, and the sodium content of perennial and annual grasses. Stocking rate affected chemical composition in the third and fourth year: the high stocking rate increased the nitrogen contents of the three major components, the phosphorus and sulphur contents of Townsville stylo and perennial grasses, and the sodium contents of perennial and annual grasses. Cow conception rate was significantly and positively correlated with the phosphorus contents of the three major components, the sulphur content of Townsville stylo, and three yield attributes of annual grasses (dry matter, phosphorus, and nitrogen yield). The phosphorus content of all three components was less than 0.15% for much of the year at the two lower rates of superphosphate; only at the highest rate did the pastures approach an adequate phosphorus content for pregnant and lactating cows. Phosphorus and sulphur deficiency could have limited the utilization of Townsville stylo protein by cattle on unfertilized pastures. Superphosphate at a rate of 126 kg/ha a year was adequate for maintaining Townsville stylo above the critical plant value for phosphorus, but inadequate to satisfy the phosphorus requirements of pregnant and lactating cows.


1970 ◽  
Vol 10 (47) ◽  
pp. 710 ◽  
Author(s):  
MJT Norman ◽  
LJ Phillips

At Katherine, N.T., stocking rates of 1.33, 1.00, and 0.67 Shorthorn steers an acre for a period of 18 weeks in the wet season beginning January were imposed on established pastures sown to Townsville sty10 (Stylosanthes humilis) alone but subsequently invaded to varying degrees by annual grasses. The experiment was repeated over three years. There were no significant differences in mean liveweight gain per head over three years ; hence liveweight gain per acre at the heaviest stocking rate was approximately twice that at the lightest rate. The mean dry matter yield of grass increased significantly with decreasing stocking rate, but there were no significant differences between stocking rates in Townsville stylo dry matter yield, nitrogen yield, or phosphorus yield. Correlation coefficients were calculated using data from individual paddocks and years. There was a highly significant positive correlation between liveweight gain per head and pasture nitrogen yield, and between liveweight gain per head and pasture phosphorus yield.


1974 ◽  
Vol 14 (67) ◽  
pp. 146 ◽  
Author(s):  
L Winks ◽  
FC Lamberth ◽  
KW Moir ◽  
PM Pepper

The performance of steers grazing Townsville stylo (Stylosanthes humilis)-native grass pasture, with and without superphosphate fertilizer, was studied at two stocking rate (0.41 and 0.82 beasts ha-1) on the sub-coastal spear grass region of the dry tropics of north Queensland over a period of three and a half years. Fertilizer increased yield and quality of pasture, but invasion of the fertilized areas by annual grass species was occurring by the end of the study. Liveweight gains on fertilized Townsville stylo pastures were greater than on unfertilized Townsville stylo, where performance was similar to that recorded on untreated native pasture at stocking rates of 0.25 and 0.41 beasts ha-1. Liveweight gains at the lighter stocking rate were greater than at the higher level on the Townsville stylo-native grass pasture, but at the stocking rates applied to native pasture there was no significant effect of stocking rate. A stocking rate of 0.41 beast ha-1 on fertilized Townsville stylo was safe in all years. Wastage of material was high owing to mould development on the Townsville stylo which remained as standing hay during the winter.


1989 ◽  
Vol 48 (3) ◽  
pp. 519-533 ◽  
Author(s):  
T. Nolan ◽  
J. Connolly

ABSTRACTThe effects of mixed v. mono-grazing by steers and sheep on individual animal growth rate, pasture carrying capacity and live-weight output per ha were measured in a 4-year (1978 to 1981) experiment, after a preliminary familiarization year, 1977. Annual stocking rate treatments consisted of three monosteer, three mono-sheep and seven mixtures of steers and sheep. Annual average stocking rates were 2·11 steers † 8·1 ewes per ha under mixed grazing and, under mono-grazing, 4·44 steers and 15·2 ewes per ha. The range from low to high in stocking rate in mono- or mixed grazing was close to 40%. Over the 4 years a total of about 280 steers, 900 ewes and 1100 lambs were used.Overall, mixed grazing increased average lamb daily live-weight gain (ADG) to weaning and to drafting from 246 to 265 g (P < 0001) and from 211 to 223 g (P < 0·001) respectively. Steer ADG for these periods was increased from 1·419 to 1·520 kg (P < 0·01) and from 0·950 to 1·094 kg (P < 0·001). The choice of reference mono-grazing stocking rates for comparisons of mixed v. mono-grazing ADG can affect these results. Average live-weight outputs (kg/ha) from grazing for the mono-steers, mono-sheep, and mixed grazing were 663, 690 and 714, the range in the latter over the seven mixed grazing treatments being from 605 to 805. Stocking rate was the main factor affecting output per ha. Because of the management rules used in this experiment mixed grazing effects are more appropriately assessed through ADG and measures based on it than on output per unit of area.Models were fitted relating steer and lamb ADG to lamb weaning and lamb and steer drafting to stocking rates of steers and ewes. Mixed grazing benefits to steer and lamb ADG to drafting were greater as their proportion in the mix declined and increased with stocking rate. At the 50% proportion, lamb and steer ADG were improved by 5·2 and 3·4% respectively at low stocking rate and 9·4 and 6·6 at high stocking rate. Predicted steer ADG to lamb weaning for a given steer stocking rate increased with increases in ewe proportion up to five ewes per ha and decreased rapidly with further increments in ewe proportion.Mixed grazing efficiency was also evaluated through the Relative Resource Total. This showed that under mono-grazing 10 to 13% more area was required to produce the same grazing season output as under mixed grazing. The 10% improvement in carrying capacity was exceeded for ewe: steer frequencies ranging from 1·5: 1 to 10: 1. Explanations for this greater efficiency in resource capture/use under mixed grazing are discussed.Substitution rates for lamb ADG to weaning (2·35) and to drafting (2·86) and for steer ADG to drafting (0·21) were fairly constant over the 4 years 1978 to 1981.Selection of mixed stocking rates to suit growth rate targets for different animal types and to match food supply with demand under varying soil/climatic/topographical conditions is discussed.


1969 ◽  
Vol 20 (6) ◽  
pp. 1123 ◽  
Author(s):  
AD Wilson ◽  
H Leigh ◽  
WE Mulham

A study was made of Merino sheep grazing a bladder saltbush (Atriplex vesicaria Hew. ex Benth.)–cotton-bush (Kochia aphylla R.Br.) community set stocked at three stocking rates (2.5, 1 .2, and 0.6 sheep/hectare) over a 3-year period. In spring the sheep preferred the perennial grass Danthonia caespitosa Gaudich. and the annuals Medicago polymorpha L. and Vulpia myuros (L.) K. C. Gmel. to the more abundant A. vesicaria. From summer to early winter the diet consisted mainly of A. vesicaria with the proportion of dead matter and Medicago burr increasing as the availability of A. vesicaria decreased. Seasonal fluctuations in wool growth were evident at all three stocking rates. Maximum wool growth rates occurred in spring when the nitrogen content (2.3%) and in vitro digestibility (65%) of the forage eaten was high. During autumn and early winter values for nitrogen (1.4%) and digestibility (50%) were lower and wool growth was at a minimum. At 0.6 sheep/ha animal productivity was maintained and there was little decline in the A. vesicaria population during the 3 years. Grazing eliminated all the A. vesicaria from the pasture stocked at 2.5 sheep/ha, and 98% at 1.2 sheep/ha. At these higher stocking rates the pasture proved incapable of maintaining the sheep for the 3-year period. The inability of A. vesicaria to recover after heavy or complete defoliation by grazing demonstrates the necessity of adopting a low stocking rate if the bush is to be retained.


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