A biophysical dairy farm model to evaluate rotational grazing management strategies

This paper reports changes in livestock weights recorded in a whole-farmlet experiment, which aimed to examine the profitability and sustainability of three different pasture and grazing management strategies. The assessment of liveweights was considered a key component of measuring the integrated effects of the farmlet-scale treatments. The three farmlets comprised a typical management regime, which employed flexible rotational grazing over eight paddocks with moderate soil fertility (farmlet B), a system based on the same grazing management and paddock number but with higher levels of sown pasture and soil fertility (farmlet A) and a farmlet with moderate soil fertility and intensive rotational grazing over 37 paddocks (farmlet C). Early in the experimental period, there were no significant differences between farmlets in the liveweight of any class of livestock. However, from the second year onwards, as the pasture renovation, soil fertility and grazing management treatments took effect, differences in liveweight between farmlets became more apparent and significant. The stocking rate, which was treated as an emergent property of each farmlet, reached a maximum annual average value after 5 years of 12.6, 8.5 and 7.7 dry sheep equivalents (dse)/ha on farmlets A, B and C representing 84, 113 and 51% of their respective target stocking rates which were 15, 7.5 and 15 dse/ha. The liveweights of ewes, both before joining and during pregnancy, varied with year and farmlet with those on farmlets A and B tending to be significantly heavier than those on farmlet C. From 2003 to 2006, liveweights were significantly (P < 0.001) affected by a wide array of factors and their interactions including: date, ewe age, green digestible herbage, legume herbage mass, proportion of farmlet grazed, stocking rate and level of supplementary feeding. The weights of lambs/weaners/hoggets, both pre- and post-weaning, were at times also higher on farmlets A and B compared with those on farmlet C and were affected by a similar range of factors to those which affected ewe weights. Similar relative differences also applied to the liveweights of the other livestock run on the farmlets, namely wethers and non-reproductive cattle. The results suggest that stocking rate was able to be increased towards the higher target of farmlet A due to the higher level of pasture renovation and soil fertility on that farmlet, which led to high liveweights per head as well as the higher stocking rate. However, as the stocking rate increased on farmlet A, the differences between farmlets in liveweight per head diminished and the need for supplementary feeding increased. In contrast, the intensive rotational grazing practised on farmlet C did not allow the farmlet to increase its stocking rate towards its higher target. It appears that the higher proportion of each of farmlets A and B grazed at any one time allowed all classes of livestock to reach higher liveweights per head than on farmlet C, due presumably to the greater proportion of those two farmlets grazed at any one time.

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Changes in botanical composition on three farmlets subjected to different pasture and grazing management strategies

Animal Production Science ◽

10.1071/an11177 ◽

2013 ◽

Vol 53 (8) ◽

pp. 670 ◽

Cited By ~ 22

Author(s):

L. M. Shakhane ◽

J. M. Scott ◽

R. Murison ◽

C. Mulcahy ◽

G. N. Hinch ◽

...

Keyword(s):

Soil Fertility ◽

Initial Conditions ◽

Management Strategies ◽

The Other ◽

Grazing Management ◽

Curvilinear Relationship ◽

Botanical Composition ◽

Rotational Grazing ◽

Tall Grass ◽

Soil P

As part of the Cicerone Project’s farmlet experiment, conducted on the Northern Tablelands of New South Wales, Australia, between July 2000 and December 2006, this study assessed the effects of varying soil fertility, pasture species and grazing management on the botanical composition of three 53-ha farmlets subjected to different management strategies. Starting with the same initial conditions, the farmlets were managed to reach different target levels of soil phosphorus (P) and sulfur (S); Farmlet A aimed at 60 mg/kg of Colwell P and 10 mg/kg S (KCl40) whereas Farmlets B and C both aimed at 20 and 6.5 mg/kg of P and S, respectively. Pastures were renovated on six out of eight paddocks on Farmlet A, but only one paddock of each of Farmlets B (typical management) and C (intensive rotational grazing) was renovated. Flexible rotational grazing was employed on Farmlets A and B (each of eight paddocks) while Farmlet C used intensive rotational grazing over its 17 major paddocks, which were further subdivided into 37 subpaddocks. This paper focuses on the botanical composition dynamics observed across all three farmlets and the explanatory variables associated with those changes. Eight assessments of botanical composition were carried out at approximately annual intervals across each of the 37 major paddocks distributed across the farmlets and the results for each of 49 species were aggregated into seven functional groups for analysis. The strongest correlation found was a negative curvilinear relationship between sown perennial grasses (SPG) and warm-season grasses (WSG). The most significant factors affecting the functional group changes were soil P, sowing phase, paddock and date. These factors led to significant increases in SPG and correspondingly lower levels of WSG on Farmlet A compared with Farmlet B. Farmlets B and C experienced similar, declining levels of SPG, and increasing levels of WSG suggesting that intensive rotational grazing did not lead to substantial changes in botanical composition, compared with flexible rotational grazing, in spite of the fact that intensive rotational grazing had much longer grazing rests and shorter graze periods than the other two farmlets. Soil P levels were also significantly associated with levels of cool-season annual grasses, legumes and herbs, especially on Farmlet A. In general, the largest differences in botanical composition were between Farmlet A and the other two farmlets; these differences were most closely associated with those plants categorised as sown, introduced, C3 pasture species. The levels of legume were generally low on all farmlets, due largely to the dry seasons experienced over most of the trial. Efforts to increase the legume composition on all farmlets were more successful on Farmlet A than on the other two farmlets due, presumably, to higher soil fertility on Farmlet A. Farmlet C, with its long rest periods and short graze periods, had a small proportion of legumes, due to the competitive effects of the accumulated tall grass herbage between grazings. The ‘typical’ management of Farmlet B also resulted in low levels of legume as well as increased ‘patchiness’ of the pastures and increased numbers of thistles.

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Effect of grazing management strategies on the yield and nutritional value of Marandu grass in the semiarid of Brazil

Semina Ciências Agrárias ◽

10.5433/1679-0359.2021v42n4p2503 ◽

2021 ◽

Vol 42 (4) ◽

pp. 2503-2522

Author(s):

Maria Catiane Silva Veloso Araújo ◽

◽

Eleuza Clarete Junqueira de Sales ◽

Flávio Pinto Monção ◽

Vicente Ribeiro Rocha Júnior ◽

...

Keyword(s):

Dry Matter ◽

Nutritional Value ◽

Accumulation Rate ◽

Structural Characteristics ◽

Block Design ◽

Management Strategies ◽

Grazing Management ◽

Rotational Grazing ◽

Pasture Management ◽

Sward Height

The objective of this study was to evaluate the effects of two grazing management strategies on structural, productive and nutritional parameters of Marandu grass (Urochloa brizantha cv. Marandu). A completely randomized block design with two pasture management strategies and eight replications (blocks) was used. The grazing management strategies were: (1) low intensity rotational grazing (LI), with a pre-grazing sward height of 40 cm and a post-grazing sward height of 24 cm, i.e., a defoliation intensity of 50%; (2) High intensity rotational grazing (HI), with a pre-grazing sward height of 40 cm and a post-grazing sward height of 10 cm (±70% defoliation intensity). Pastures were sampled before and after grazing for estimation of forage mass, forage accumulation rate, structural characteristics, nutritional value and dry matter intake.The LI strategy resulted in higher dry matter production than HI before (18.33%) and after grazing (49.06%), increasing pre-grazing forage density by 13.21% (P < 0.05). The production of potentially digestible dry matter was highest (P < 0.05) in LI strategy (21.3% before and 39.6% after grazing, respectively). Higher post-grazing green forage mass (45%) increased the residual crude protein in LI. The LI management strategy increased forage mass production and can be used in Marandu grass pastures.

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The effects of pasture inputs and intensive rotational grazing on superfine wool production, quality and income

Animal Production Science ◽

10.1071/an12289 ◽

2013 ◽

Vol 53 (8) ◽

pp. 750 ◽

Cited By ~ 16

Author(s):

D. Cottle ◽

C. A. Gaden ◽

J. Hoad ◽

D. Lance ◽

J. Smith ◽

...

Keyword(s):

Soil Fertility ◽

Management Strategies ◽

Fibre Diameter ◽

Production Quality ◽

Grazing Management ◽

Rotational Grazing ◽

Wool Production ◽

Staple Strength ◽

Fleece Weight ◽

Staple Length

A farmlet experiment was conducted between July 2000 and December 2006 as part of the Cicerone Project, which sought to enhance the profitability and sustainability of grazing enterprises on the Northern Tablelands of New South Wales, Australia. A self-replacing Merino enterprise was grazed as the dominant livestock enterprise, together with ~20% of the carrying capacity as cattle, on each of three farmlet treatments: higher levels of soil fertility and pasture renovation with flexible rotational grazing over eight paddocks (farmlet A), moderate soil fertility and pasture renovation with flexible rotational grazing over eight paddocks (farmlet B) and moderate soil fertility and pasture renovation with intensive rotational grazing over 37 paddocks (farmlet C). Prior to commencement of the trial, the three 53-ha farmlets were allocated equivalent areas of land based on soil type, slope and recent fertiliser history. This paper describes the effects of the three pasture and grazing management strategies on the production, quality and value of the wool produced per head, per ha and per farmlet. Up until 2001 there were no differences in wool production between farmlets. Thereafter, significant differences between farmlets emerged in greasy fleece weight per head and price received per kg of fleece wool. For example, the clean fleece value averaged over the 2003–05 shearings for all hoggets, ewes and wethers was 1531, 1584 and 1713 cents/kg for farmlets A, B and C, respectively. There were small but significant differences, which varied between sheep class and year, between the farmlets in average fibre diameter and staple length but less so with staple strength. In general, while the differences between farmlets in staple strength varied over time, farmlets A and B tended to have wool with longer staple length and broader fibre diameter than farmlet C and this affected wool value per kg. Differences in wool income per ha between farmlets grew in later years as the farmlet treatments took effect. In spite of farmlet A having a slightly lower wool value per kg, after taking into account its greater fleece weight per head and its higher stocking rate, the total wool income per ha was higher than on either farmlets B or C. The average gross wool income per ha from 2003 to 2005 was $303, $215 and $180 for farmlets A, B and C, respectively. The highest amount of greasy wool produced was in 2004 when 38.2, 26.5 and 21.5 kg/ha was harvested from farmlets A, B and C, respectively. The fibre diameter profiles of 2-year-old ewes showed similar profiles for farmlets A and B but a significantly finer fibre diameter profile for farmlet C ewes due to intensive rotational grazing. However, sheep on all three farmlets produced wool with high staple strength. Multivariate analyses revealed that greasy fleece weight, staple length and staple strength were significantly positively correlated with the proportion of the farm grazed at any one time, and with soil phosphorus, legume herbage and green digestible herbage thus highlighting the significant influence of pasture and soil inputs and of grazing management on wool production and quality.

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Addressing on-farm management to enhance pasture productivity and persistence

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2013.75.2914 ◽

2013 ◽

pp. 241-244

Author(s):

W.N. Reynolds

Keyword(s):

Management Strategies ◽

Dairy Farm ◽

Stocking Rate ◽

Pasture Management ◽

Pasture Production ◽

Operating Profit ◽

The North ◽

The Cost ◽

On Farm ◽

Attention To Detail

Following the 2007/08 drought, we experienced poor pasture production and persistence on our dairy farm in north Waikato, leading to decreased milksolids production and a greater reliance on bought-in feed. It is estimated that the cost of this to our farming operation was about $1300 per hectare per year in lost operating profit. While climate and black beetle were factors, they did not explain everything, and other factors were also involved. In the last 3 years we have changed our management strategies to better withstand dry summers, the catalyst for which was becoming the DairyNZ Pasture Improvement Focus Farm for the north Waikato. The major changes we made were to reduce stocking rate, actively manage pastures in summer to reduce over-grazing, and pay more attention to detail in our pasture renewal programme. To date the result has been a reduced need for pasture renewal, a lift in whole farm performance and increased profitability. Keywords: Focus farm, over-grazing, pasture management, pasture persistence, profitability

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Grazed pasture parameters. I. Pasture dry-matter production and availability in a stocking rate and grazing management experiment with dairy cows

The Journal of Agricultural Science ◽

10.1017/s0021859600068283 ◽

1966 ◽

Vol 67 (2) ◽

pp. 199-210 ◽

Cited By ~ 31

Author(s):

A.G. Campbell

Keyword(s):

Dairy Cow ◽

Dry Matter ◽

Grazing Management ◽

Dry Matter Production ◽

Small Scale ◽

Stocking Rate ◽

Rotational Grazing ◽

Pasture Production ◽

Grazed Pasture ◽

Matter Production

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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Ranking Dairy Sires by a Linear Programming Dairy Farm Model

Journal of Dairy Science ◽

10.3168/jds.s0022-0302(84)81667-7 ◽

1984 ◽

Vol 67 (12) ◽

pp. 3015-3024 ◽

Cited By ~ 19

Author(s):

S. Sivarajasingam ◽

E.B. Burnside ◽

J.W. Wilton ◽

W.C. Pfeiffer ◽

D.G. Grieve

Keyword(s):

Linear Programming ◽

Dairy Farm ◽

Farm Model

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Regenerative rotational grazing management of dairy sheep increases springtime grass production and topsoil carbon storage

Ecological Indicators ◽

10.1016/j.ecolind.2021.107484 ◽

2021 ◽

Vol 125 ◽

pp. 107484

Author(s):

Xabier Díaz de Otálora ◽

Lur Epelde ◽

Josune Arranz ◽

Carlos Garbisu ◽

Roberto Ruiz ◽

...

Keyword(s):

Carbon Storage ◽

Grazing Management ◽

Dairy Sheep ◽

Rotational Grazing ◽

Grass Production

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Adaptive, Multipaddock Rotational Grazing Management: A Ranch-Scale Assessment of Effects on Vegetation and Livestock Performance in Semiarid Rangeland

Rangeland Ecology & Management ◽

10.1016/j.rama.2020.07.005 ◽

2020 ◽

Vol 73 (6) ◽

pp. 796-810 ◽

Cited By ~ 2

Author(s):

David J. Augustine ◽

Justin D. Derner ◽

María E. Fernández-Giménez ◽

Lauren M. Porensky ◽

Hailey Wilmer ◽

...

Keyword(s):

Grazing Management ◽

Rotational Grazing ◽

Scale Assessment ◽

Semiarid Rangeland

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Dietary preference of dairy cows grazing grass and clover

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200597038 ◽

1998 ◽

Vol 1998 ◽

pp. 51-51

Author(s):

S.M. Rutter ◽

R.J. Orr ◽

P.D. Penning ◽

N.H. Yarrow ◽

R.A. Champion ◽

...

Keyword(s):

Dairy Cows ◽

Nutrient Intake ◽

Management Strategies ◽

Grazing Management ◽

Considerable Progress ◽

Dietary Preference ◽

Domestic Ruminants ◽

Factors Influencing ◽

Lactating Dairy Cows ◽

Grazing Sheep

The development of grazing management strategies to optimise nutrient intake from grazed herbage requires an understanding of the factors influencing the dietary preference of grazing domestic ruminants. Although there has been considerable progress in understanding the factors influencing the dietary preference of grazing sheep, there has been comparatively little research with lactating dairy cows (Rutter et al., 1997). The aim of the experiment reported here was to study the dietary preference of lactating dairy cows grazing grass and clover.

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