scholarly journals Effects of three whole-farmlet management systems on Merino ewe fat scores and reproduction

2013 ◽  
Vol 53 (8) ◽  
pp. 740 ◽  
Author(s):  
G. N. Hinch ◽  
M. Lollback ◽  
S. Hatcher ◽  
J. Hoad ◽  
R. Marchant ◽  
...  

As part of the Cicerone Project’s whole-farmlet experiment on the Northern Tablelands of New South Wales, Australia, the fat scores and reproductive performance of ewes were measured to assess the effect of different management systems on these important production parameters over time. The three farmlets (each of 53 ha) included one (farmlet B) subjected to ‘typical’ district management consisting of moderate levels of inputs and a target stocking rate of 7.5 dse/ha, with flexible grazing management across eight paddocks. A second farmlet (A) was managed in a similar fashion to farmlet B with respect to number of paddocks and grazing management, but modified by high rates of pasture renovation and higher levels of soil fertility, with a target stocking rate of 15 dse/ha. The third farmlet (C) was managed at the same level of moderate inputs as farmlet B but employed intensive rotational grazing over 37 paddocks and also had a high target stocking rate of 15 dse/ha. The experiment was conducted over 6.5 years from July 2000 to December 2006. In spite of the fact that target levels of stocking rate were chosen at the beginning of the experiment, stocking rate, together with fat scores and reproduction were treated as emergent properties of each farmlet system. Joining took place in April–May and lambing occurred in September–October of each year. Over the first 2 years of the experiment, there were few differences among farmlets in ewe fat scores or reproductive performance. From 2003 onwards, while the percentage of ewes pregnant was similar between farmlets, the average proportion of multiple births (ewes scanned in late July, with twins) was 30%, 16% and 12%, respectively, on farmlets A–C. However, lamb losses were greater on farmlet A, with average lamb mortalities recorded on farmlets A–C of 29%, 10% and 19%, respectively. Over the duration of the experiment, ewes on farmlets A and B were more often above a fat score level of 3, and less often below 2.5, than were ewes from farmlet C. Differences among farmlet ewes in fat score were found to be significant in 7 of the total of 13 assessments over the duration of the experiment. A generalised additive model applied to whole-farmlet data showed that green digestible herbage, legume herbage, stocking rate, the amount of supplement fed and especially the proportion of each farmlet grazed at any one time all influenced fat scores of ewes. While fat scores and conception rates tended to be highest on farmlet A, farmlet B had slightly better reproductive outcomes due to less lambing losses, whereas ewes on farmlet C tended to have somewhat lower fat scores and levels of reproduction. These farmlet-scale findings highlighted the importance for livestock managers to focus not only on grazing management, stocking rate and stock density during lambing, but also on the availability of sufficient green, and especially legume herbage, and the difficulty of overcoming a deficit in quality herbage with supplementation.

1966 ◽  
Vol 67 (2) ◽  
pp. 217-221 ◽  
Author(s):  
A. G. Campbell

1. Pasture parameters have been correlated with animal production parameters from a trial in which two management systems (‘controlled’ and ‘uncontrolled’ grazing), each at two stocking rates (0.95 and 1.19 cows/acre), were compared.2. Per acre butterfat production was positively related to percentage utilization of available D.M., but negatively related to yield of available D.M.3. Per cow butterfat production was significantly and positively correlated with yield of available D.M. in the two months after calving (August and September) and in the penultimate month of lacta-tion (April), but this correlation was not significant in other months.4. It is concluded that management system was as important as stocking rate in increasing the utilization of pasture and animal production from pasture.


1979 ◽  
Vol 19 (97) ◽  
pp. 208 ◽  
Author(s):  
GJ Leach

Survival of lucerne plants and changes in the row cover of lucerne in relation to grazing management were studied in an experiment at Lawes, south-east Queensland, from 1971 to 1977. There were six grazed treatments (resting for 32 or 44 days combined with grazing for 4 or 16 days, resting for 56 days with grazing for 4 days, and resting for 40 days with grazing for 8 days) and three mown treatments (mown every 36,48 or 60 days). All grazing was with sheep, at a stocking rate equivalent to 20 ha-1 on a year round basis. The experiment was irrigated when necessary to ensure that moisture at least equivalent to the long-term average monthly rainfall was received. There were about 42 lucerne plants m-2 in November 1971 and about 13 plants m-2 in October 1977; thus lucerne survival was good in all treatments, with stands losing about five plants m-2 annum-1. Management effects were small, with survival and row cover becoming slightly better as the interval between grazings or mowings increased from 32 to 60 days. Grazing for four days gave poorer survival than either grazing for 8 or 16 days or mowing. Perennial grass cover was much greater with four-day grazing than in the other treatments. Inspection at the end of the experiment showed nearly all crowns to have moderate symptoms of crown rot caused by Colletotrichum trifolii. The need for critical attention to the interaction between moisture supply, grass invasion and disease accumulation in maintaining lucerne stands in sub-tropical environments is discussed.


2020 ◽  
Vol 60 (3) ◽  
pp. 414
Author(s):  
Susan M. Robertson ◽  
Michael A. Friend

Management system has the potential to alter the reproductive output of sheep flocks and thereby farm profit. A study was conducted between 2006 and 2010 to evaluate the reproductive performance of four management systems with differing combinations of time of lambing, stocking rate and ram breed, while grazing at a similar midwinter stocking rate (dry-sheep equivalents per hectare of 8, 10.2, 13, 11.2 and 11.2 in the successive seasons 2006–2010). Three systems, winter lambing Merino (WLM), split lambing (SL) and later lambing (LL), grazed replicated farmlets comprising pastures that were 20% lucerne (Medicago sativa), 20% tall fescue (Festuca arundinacea) and 60% phalaris (Phalaris aquatica). A fourth system (high lucerne (HL)) grazed farmlets of 40% lucerne, 15% tall fescue and 45% phalaris. All systems used Merino ewes: in WLM mated to Merino rams, lambing in July; in SL half of the ewes lambing to terminal-breed rams in July, the other half lambing to Merino rams in September; and in LL and HL lambed in September, half to terminal-breed and half to Merino rams. The number of lambs weaned per ewe joined was 10% higher (P < 0.05) in the WLM system (0.99 ± 0.03) than in the September-lambing systems LL and HL, largely a result of a higher number of fetuses per ewe and despite lower (P < 0.05) lamb survival to marking in some years. The SL system weaned a similar (P > 0.05) number of lambs per ewe (0.95 ± 0.03) to all other systems. However, the number of lambs weaned per hectare was least in WLM (4.6 ± 0.2), lower than in the HL and LL systems by 2.7 lambs/ha because of a lower stocking rate. The ranking of systems for fetal number and lamb survival was not consistent among years. Spring-lambing systems produced more lambs per hectare because of a higher stocking rate but fewer lambs per ewe than the WLM system. System differences in pregnancy rate, fecundity and lamb survival were not consistent between years.


Author(s):  
B.S. Thorrold ◽  
K.F. O'Connor ◽  
J.G.H. White

The behaviour of Merino wether hoggets grazing an existing management experiment at Tara Hills High Country Research Station was studied during summer 198111982. The experiment compared three stocking rates and three management systems (continuous, two paddock intermittent grazing, six paddock rotational). The daytime distribution and activity of the hoggets, dung distribution, and Olsen-P levels of topsoils were recorded on ten altitudinal strata within each of the nine treatment areas. Dung frequency was more closely correlated to grazing distribution than to either resting or total animal distribution. This is contrary to the generally accepted belief that dung accumulation is associated with resting behaviour. Increasing stocking ra?e !ed ?o a more even grazing and dung distribution. Subdivision by itself did not improve the evenness of distribution although it may have enhanced the stocking rate influence. There was little correlation between dung frequency and soil Olsen- P levels, especially outside the night camp areas. This indicates the importance of factors such as plant uptake and herbage consumption in the phosphate nutrient cycle. Olsen-P levels were consistently higher in the high stocking rate paddocks relative to the low stocking rate. Levels in the medium stocking rate fluctuated between these two. The implications of these findings in regard to the effects of intensification of farming in the high country on nutrient cycling and fertiliser requirements are discussed. Keywords: animal behaviour, dung distribution, tussock grasslands, phosphate, grazing management.


1975 ◽  
Vol 15 (73) ◽  
pp. 173 ◽  
Author(s):  
AH Bishop ◽  
HA Birrell

In a 4 x 4 x 3 factorial experiment lasting three years, the effects of stocking rate, fodder conservation and three grazing management systems (continuous, deferred and rotational) on the wool production of wethers grazing perennial pasture were assessed. The hay conserved on the plots was fed to the sheep in such a way that the quantities made and fed would balance over a period of years. At the highest rate of stocking some oats were fed in adverse seasons. Stocking rate had the major effect on wool production in all years. Improving wool production by fodder conservation was shown to depend on stocking rate, grazing management and the seasonal conditions. In some instances fodder conservation was shown to interact with stocking rate in a manner such that the maximum response tended to occur when smaller proportions of area were conserved as stocking rate increased. The implications of this interaction are discussed. Fodder conservation increased wool production in the continuous and rotationally grazed systems in all years, but did not in two of the three years with deferred grazing. The biggest increases in wool production due to fodder conservation occurred in the third year, the driest on record when a drought reserve was used. Wool production was also influenced by the grazing management. In alt-years there was a consistent interaction with stocking rate in which the highest wool production was produced in the rotational system at high stocking rates and in the deferred system at low stocking rates.


1962 ◽  
Vol 42 (2) ◽  
pp. 139-144 ◽  
Author(s):  
F. W. Calder ◽  
J. W. G. Nicholson ◽  
H. M. Cunningham

Two experiments were conducted to compare forward creep grazing of lambs with other grazing management systems for ewes and lambs. In the first experiment, forward creep grazing with and without creep feeding of concentrates was compared with rotational grazing, using 7 ewes with single lambs per plot of [Formula: see text] acres. The first lambs reached market weight by the 57th day of the experiment, at which time the average lamb gains were higher on the creep grazed-creep fed groups, but there was no difference in the gains on the other two systems. The experiment was continued for 35 days and during this period the lamb gains on the creep grazed plots were higher than on the rotationally grazed areas. This later period coincided with a period of reduced herbage growth due to below normal precipitation. The average daily gains for the entire experimental period were.45,.51 and.57 pounds for rotational, creep, and creep fed-creep grazed systems respectively.In the second experiment, forward creep grazing was compared with rotational grazing and free range grazing, using a higher stocking rate of 8 ewes and 10 lambs per plot. The average daily gains for the experiment were.38,.40 and.34 pounds for rotational, creep grazed, and free range systems respectively. The differences between grazing systems were not statistically significant at P = 0.05. Both the ewe and lamb gains were lower on the free-range system than on the other systems. The ewe gains were higher on the rotationally grazed areas than the forward creep grazed areas in both experiments. This indicates that forward creep grazing of lambs can be advantageous under conditions where herbage is abundant.Evidence obtained from helminth ova counts on fecal samples, and examination of representative digestive tracts of the lambs marketed, indicated that the forward creep grazing of lambs reduced but did not prevent a build-up of internal parasites.


2017 ◽  
Vol 57 (9) ◽  
pp. 1849 ◽  
Author(s):  
K. M. Broadfoot ◽  
W. B. Badgery ◽  
G. D. Millar

Assessments of grazing systems are often constrained by the decisions regarding the management of the grazing systems, including stocking rate, and also the seasonal conditions that occur during the assessment period. These constraints have led to sometimes conflicting results about comparisons of grazing management systems. This paper examines 1-, 4- and 20-paddock (1P, 4P and 20P) grazing management systems to determine how the intensity of grazing management on native pastures influences the financial performance of sheep production systems. The performance of the grazing systems, as part of the Orange EverGraze research experiment, was initially examined using the biophysical data over the 4 years of the experiment and then a more detailed analysis over a longer timeframe was undertaken using the AusFarm simulation modelling software. Flexible management strategies to optimise ewe numbers, sale time of lambs, and adjust ewe numbers based on season, were also assessed to determine which management systems are the most profitable and sustainable. There was higher profit for the 20P grazing system than the 1P system during the experiment. However, when stocking rates were held constant at optimum levels and systems were simulated over 40 years, there was no difference between grazing systems. Modelling strategies used to vary stocking rates showed that flexible management options are better based on optimising ewe numbers and the sale time of lambs rather than changing ewe numbers between years. The sustainability of modelled systems was also assessed using frequency of events where the average herbage mass (0.8 t DM/ha) or ground cover (80%) in autumn dropped below levels that are associated with degradation. Degradation events occurred more so with increasing ewe number than lamb sale time. Overall, the most sustainable systems, when considering profitability and environmental issues, had a stocking rate of 4.2 ewes per ha, with lambs sold in February (2 or 18). Higher stocking rates (5.3 ewes/ha) would need to be run for more intensive grazing management to have higher profitability.


Author(s):  
J. Hodgson

Recent assessments of the relative importance of stocking rate. stocking policy and grazing management on the output from pastoral systems are used as a starting point to argue the need for objective pasture assessments to aid control of livestock enterprises to meet production targets. Variations in stocking rates, stocking policy and other management practices all provide alternative means of control of pasture conditions which are the major determinants of pasture and animal performance. Understanding of the influence of pasture conditions on systems performance should provide a better basis for management control and for Communication between farmers, extension officers and researchers. Keywords: Stocking rate, pasture condition, pasture cover


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.


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