Organic Pasture Research Articles

Growth, carcass characteristics, and profitability of organic versus conventional dairy beef steers

Bull calves (n=49), born at the University of Minnesota West Central Research and Outreach Center (Morris) between March and May 2011, were used to compare growth measurements and profitability of conventional and organic dairy steers. Calves were assigned to 1 of 3 replicated groups at birth: conventional (CONV; n=16), organic (pasture and concentrate; ORG; n=16), or organic grass only (GRS; n=17), and analysis of variables was on a pen basis. Breed groups of calves were Holstein (HO; n=9); Holsteins (n=11) maintained at 1964 breed average level; crossbreds (n=19) including combinations of HO, Montbéliarde, and Swedish Red; and crossbreds (n=10) including combinations of HO, Jersey, Swedish Red, and Normande. The CONV steers were fed a diet of 80% concentrate and 20% forage. The ORG steers were fed a diet of organic corn, organic corn silage, and at least 30% of their diet consisted of organic pasture during the grazing season. The GRS steers grazed pasture during the grazing season and were fed high-quality hay or hay silage during the nongrazing season. Intakes of a total mixed ration were recorded daily with herd management software. A profit function was defined to include revenues and expenses for beef value, feed intake, pasture intake, health cost, and yardage. The GRS (358.6kg) steers had lesser total gains from birth to slaughter than ORG (429.6kg) and CONV (534.5kg) steers. Furthermore, the GRS (0.61kg/d) steers had lesser average daily gain from birth compared with ORG (0.81kg/d) and CONV (1.1kg/d) steers. The GRS and ORG steers had smaller rib eye area (49.5 and 65.8cm2, respectively) compared with CONV (75.4cm2) steers. For profitability, GRS steers had 43% greater profit than CONV steers due to organic beef price premiums and lower feed costs. On the other hand, ORG steers had substantially less profit than CONV steers. The higher cost of production for the ORG steers is due to the extreme high value of organic corn. The results of the current study illustrate the economic potential of alternative strategies for growing and marketing male offspring of organic dairy cattle in the Midwest.

Weed population dynamics for contrasting organic pasture establishment techniques

A trial was conducted on an organic dairy farm in Manawatu New Zealand to determine how well perennial weeds are controlled during pasture renewal Changes in weed populations were monitored following three different nonchemical methods of regrassing Regrassing by planting pasture 4 weeks after ploughing the old pasture (grassto grass) was compared for spring and autumn cultivation The third method involved ploughing in spring growing turnips over summer then regrassing in autumn All three techniques caused significant increases in broadleaved dock (Rumex obtusifolius) and creeping buttercup (Ranunculus repens) populations Although both these species regrew from vegetative organs it was the establishment of new seedlings following cultivation that appeared to increase populations most This buildup of dock seedlings occurred more when using a crop than just grasstograss systems A 2week fallow after ploughing gave better control of perennial weeds than having no fallow but a 4week fallow gave little further improvement

Technical efficiency of organic pasture farming in Germany: The role of location economics and of specific knowledge

AbstractWe analyze the efficiency of organic pasture farming in Germany using data from 1994/95 to 2005/06. Five inputs and one output are analyzed by means of a stochastic frontier production function, allowing for heteroscedasticity and technical effects. Five sets of possible determinants of technical efficiency are considered in the model. These include: (1) farm structure and resources; (2) human capital and management capacities; (3) institutional choice; and (4) subsidies. To these factors that are commonly included in technical effects models, we add (5) a set of variables that capture localization and urbanization economies such as the share of organic farms in a region and the regional share of votes for the Green Party in recent elections. These regional effects are found to have a significant impact on the technical efficiency of organic farms. The evolution of efficiency on farms that are converting from conventional to organic farming is also analyzed.

Soil fauna in sheep-grazed hill pastures under organic and conventional livestock management and in an adjacent ungrazed pasture

Abstract Organic pasture management includes a focus on mixed livestock grazing, restrictions on nutrient inputs and livestock pest control. These are all factors which influence the environment of soil invertebrates. In this study, soil macrofauna, mesofauna and microfauna were collected from duplicate 11 and 20 year old organic and conventional legume-based sheep-grazed pasture systems. Pastures in both systems had received the same annual input of reactive phosphate rock and elemental sulphur and were stocked with the same numbers of sheep. The major difference between the two systems was absence of the chemical control of livestock pests on the organic system, resulting in lower sheep liveweights. Two ungrazed pastures which had not received any nutrient inputs for 20+ years were also sampled as part of the study to provide an additional contrast. No significant differences in either the diversity or abundance of the soil invertebrate community were found between the organic and conventional systems, despite the use of chemicals in the conventional system. The lack of difference suggests that many of the observed and reported responses to organic management reflect altered nutrient inputs and grazing management (which were the same in the current study), rather than the cessation of chemical controls in the organic system. In contrast, the invertebrate community in the unfertilised, ungrazed pasture was distinctly different from both the grazed systems. The ungrazed pasture had a higher diversity with more New Zealand endemic species than the grazed pasture. This included twice as many large Oribatida as soil pore size increased. The lower litter quality from the lack of nutrient inputs in the ungrazed pasture was reflected in both lower earthworm abundance and the Nematode Channel Ratio (indicative of a higher proportion of fungal- than bacterial-feeding nematodes), than the grazed pasture. We conclude that organic management when limited to a comparison of livestock pest control is not beneficial to soil invertebrates. Management practices such as stocking rates and fertiliser regime, by altering the soil physical environment and food resources, are more important in influencing invertebrate populations in this soil. Some would argue these altered management practices are an integral part of an organic production system.

Comparison of meat and carcass quality in organically reared and conventionally reared pasture-fed lambs

The ‘Organic’ product label guarantees a production process that avoids the use of synthetic fertilisers, pesticides and hormones and minimises recourse to pharmaceuticals or veterinary drugs; however, the product's quality remains an issue that needs to be addressed in response to consumer demand. Consequently, this study was conducted to compare the sensory and nutritional qualities of meat and carcasses from pasture-fed lambs reared organically (O) or conventionally (C). Mean lamb growth profile was kept similar between the two treatments to avoid confounding effects with lamb age or weight at slaughter. The experiment was conducted over 3 years (2005 to 2007) with 12 O and 12 C lambs each year. The O and C treatments differed in the level of on-pasture mineral N fertilisation inducing a higher proportion of white clover in the organic pasture than the conventional pasture. Lambs were slaughtered when they attained a fat class of 2 to 3, and carcass and meat quality were evaluated. Lambs were slaughtered at an average weight and age of 35.3 kg and 156 days in the O treatment, respectively, and 35.2 kg and 155 days in the C treatment, respectively. Sensory evaluation indicated that loin chops from the O treatment had a higher level of abnormal fat odour compared with the C treatment. Carcasses from the O treatment had a softer subcutaneous fat one among 3 years (2007) compared to the C treatment. These results are probably due to a higher proportion of white clover in the diet. Organically reared lambs did offer the slight advantage of muscle fatty acid containing a higher level of stearic acid, which may have positive effects in the prevention of cardiovascular disease in humans. This may be the result of a higher rumen bio-hydrogenation of C18:3n-3 due to differences in the botanical composition between the O and the C pasture. Production system had no effect on the colour characteristics of the meat and subcutaneous fat, except lightness of subcutaneous dorsal fat, which was slightly higher in the O lambs. There were no differences between O and C lambs in terms of colour stability and lipid oxidation of the meat during the 6-day refrigerated storage under gas-permeable film.

Relationships among Contrasting Measurements of Microbial Dynamics in Pasture and Organic Farm Soils

Soil bacteria exhibit short-term variations in community structure, providing an indication of anthropogenic disturbances. In this study, microbial biomass carbon (MBC), potentially mineralizable nitrogen (PMN), community level physiological profiling (CLPP), and culture-dependent DGGE (CD DGGE) fingerprinting of the 16S rRNA gene were used to compare microbial communities in organic farm and pasture soils subjected to differing agronomic treatments. Correlation analyses revealed significant relationships between MBC, PMN, and data derived from microbial community analyses. All measures separated soil types but varied in their ability to distinguish among treatments within a soil type. Overall, MBC, PMN, and CLPP were most responsive to compost and manure amendments, while CD DGGE resolved differences in legume cropping and inorganic fertilization. The results support the hypothesis that culturable soil bacteria are a responsive fraction of the total microbial community, sensitive to agronomic perturbations and amenable to further studies aimed at linking community structure with soil functions.

Soil fertility controls the size‐specific distribution of eukaryotes

The large range of body-mass values of soil organisms provides a tool to assess the organization of soil ecological communities. Relationships between log-transformed body mass M and log-transformed numerical abundance N of all eukaryotes occurring under organic pastures, mature grasslands, and seminatural heathlands in the Netherlands were investigated. The observed allometry of (M,N) assemblages of below-ground communities strongly reflects the availability of primary macronutrients and essential micronutrients. This log-linear model describes the continuous variation in the allometric slope of animals and fungi along an increasing soil fertility gradient. The aggregate contribution of small invertebrates (M < 1 microg) to the entire faunal community is highest under nutrient deficiency and causes shifts in the mass-abundance relationships. The phosphorus concentration in the soil explains 72% of these shifts but the nitrogen concentration explains only 36%, with copper and zinc as intermediate predictors (59% and 49%, respectively). Empirical evidence supports common responses of invertebrates to the rates of resource supply and, possibly, to the above-ground primary production of ecosystems.

흑염소를 이용한 유기초지조성과 식생 개선 효과

본 연구는 제경법을 이용한 유기초지 조성기술을 확립하기 위하여 2005년부터 2007년까지 3년 동안 수행하였으며 방목 축으로는 흑염소가 사용되었다. 시험설계는 관행조성구인 대조구, 퇴구비시용 후 방목구, 방목 후 퇴구비 시용구, 방목 후 퇴구비 시용 재방목구로 처리하였다. 목초정착률은 관행구인 대조구가 유기조성구에 비하여 현저하게 증가하였으며(p<0.05), 또한 건물생산성도 유기조성구에 비하여 대조구에서 현저한 증가를 나타냈다. 조성 후 연차가 경과함에 따라 식생 및 건물생산성이 개선되어 조성효과와 아울러 조성 후 관리의 중요성을 인식할 수 있다. 목초의 사료가치는 대조구와 유기조성구 모두 큰 차이는 나타나지 않았으며, 화본과 목초의 비율은 조성1년차가 2년차에 비하여 높은 경향을 보였다. 시험 종료 후 토양 성분을 조사한 결과 pH와 양이온치환용량은 시험전과 거의 변화가 없었으나 유기물과 인산 함량은 약간 증가하였다. This study was carried out to determine the effect of establishment of organic pasture by hoof cultivation with Korean black goat on productivity of grassland and properties of soil. This study was conducted from August, 2005 to September, 2008 at Cheonan, Korea. Experiment was designed composing with 4 treatment : Standard (Control, T1), Grazing after application of cattle manure (T2), Application of cattle manure after grazing (T3), Application of cattle manure at half of grazing (T4). The establishment ratio of pasture in control treatment increased significantly as compared with that of organic treatment(p<0.05). The yield of dry matter (DM) of pasture in control treatment increased significantly as compared with that of organic treatment. The contents of crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF) and dry matter digestibility (DMD) of pasture were not influenced by cattle manure and grazing method. Grasses coverage ratio in grassland in second year after grassland development were higher than that of first year. The contents of organic matter (OM) and <TEX>$P_2O_5$</TEX> in soil samples collected in organic treatment at the end of the experiment were higher than those of control. However, The pH, and the concentrations of CEC (Ca, Na and Mg) in soil samples collected in organic treatment were hardly influenced, as compared with those at the beginning of the experiment. This study suggests that the grasses and legumes coverage ratio in grassland can be improved by suitable pasture management.

Characteristics, Costs and Issues for Organic Dairy Farming

Organic milk production has been one of the fastest growing segments of organic agriculture in the United States in recent years. Despite the growing number of organic dairy operations, the characteristics of organic dairy operations and the relative costs of organic and conventional milk production have been difficult to analyze. This study, using 2005 ARMS data for U.S. dairy operations, which include a targeted sample of organic milk producers, examines the structure, costs, and challenges of organic milk production. The analysis addresses economies of size, regional differences, and pasture use in organic milk production and compares organic and conventional milk production costs. The findings suggest that economic forces have made organic operations more like conventional operations and that the future structure of the industry may depend on the interpretation and implementation of new organic pasture rules.

Seasonal nitrate levels in the soil solution of an organic pasture managed for nature conservation

Extensive management of pastures is considered as an option to enhance nature conservation in agricultural landscapes. Partial reduction of the grazing frequency from four to two rotations and discontinuing the tending of sod and sward have been tested for extensive management of a mixed pasture at the Nova Scotia College of Agriculture in Truro since 2004. It is not well known how extensification affects the N cycle of organic pastures without mineral fertilizer or manure applications. Moisture and temperature of the topsoil and nitrate content of the leachate extracted with ceramic suction cups at 0.5 m depth were monitored prior to grazing and during sward regrowth in the first and second rotation in spring of 2005 and 2006. In each year, more than 75 % of all samples contained less than 2.5 mg NO3-N L-1. A significant seasonal nitrate dynamic suggests that plant N uptake reduces nitrate leaching in the first rotation, while soil biological activity increases N supply due to soil warming in excess of plant uptake, thus raising the nitrate level in the second rotation. Extensification significantly reduced soil temperature with a concomitant albeit small decrease of nitrate levels in the soil leachate. The pasture cycled nitrogen very tightly with little room for leakages as a result of imposed treatments during the spring season. Key words: Pasture, organic, temperature, nitrogen, leaching

The performance and meat quality of Bonsmara steers raised in a feedlot, on conventional pastures or on organic pastures

The effects of production system (feeding regime and time on feed) on growth performance, yield and economics and the effects of feeding regime, pre-slaughter treatment and electrical stimulation on meat quality were evaluated. Sixty Bonsmara steers were divided into three treatment groups, viz. feedlot, organic pasture and conventional pasture feeding. The feedlot and conventional pasture groups received a diet consisting of the same components, while the organic group received a diet with approved organic components. Initial weight, final live weight, warm carcass weight, cold carcass weight, warm and cold dressing percentage, average daily gain (ADG), pH at one and 24 hours post mortem, intramuscular fat content of the loin and subcutaneous back fat thickness were measured. The effects of electrical stimulation, feeding regime and pre-slaughter rest (recovery days at the abattoir) on meat tenderness were also investigated. Feedlot cattle had significantly higher final weights, warm and cold carcass weights, warm and cold dressing percentage, ADG, intramuscular fat content and back fat thickness measurements than organic and conventional pasture cattle. Pre-slaughter resting of animals for a week at the abattoir had no effect on meat tenderness, but electrical stimulation showed a significant positive response. Growth and carcass results were used to calculate price and feed margin for the different production systems. Feedlot cattle showed a higher profit than conventional and organic pasture groups, mainly due to faster and more efficient growth. The organic pasture cattle showed higher profit than the conventional pasture cattle as a result of the premium paid for the organically produced meat.

Nitrogen and Phosphorus Losses with Drainage Runoff and Field Balance as a Result of Crop Management

Two high‐input and two low‐input crop‐management systems, one reference treatment with field crop rotation, and one long‐term moderately treated pasture were studied and compared in respect to nitrogen (N) and phosphorus (P) flow and balance. The experiment was conducted on tile‐drained plots covered by Endocalcari‐Endohypogleyic Cambisols. The least Nmin (mineral nitrogen) leaching losses were registered in the pasture. The high‐input management systems did not consistently result in larger losses of Nmin [mainly nitrate (NO3)‐N] and Ptot (total phosphorus) in the drainage water. The leaching of Nmin depended more on amount of the drainage water leaving the site, soil organic matter/humus, and soil Ntot content (positive correlation) as well as the content of water‐stable aggregates (negative correlation). The higher concentrations of Ptot in drainage runoff in the organic (ORG1) treatment and pasture during the second rotation might be conditioned of ley root system impact. Ptot leaching was positively correlated to the available P2O5‐AL in the topsoil. Negative N field balance was determined in all the treatments, except ORG2 and LTP in 1995–1999, whereas it was negative only in the reference plots (REF) in the 2001–2003 rotation because of the increased crop residues and drier climatic conditions. Phosphorus balance was slightly negative in the ORG1 and reference treatments during both rotations.

Ocular complications of barren brome exposure in a suckler herd

THE presence of a foreign body trapped between the palpebral conjunctiva and the cornea, in folds of palpebral conjunctiva, or above or below the nictitating membrane is an infrequent cause of ocular disease in cattle. Rebuhn (1995) suggested that plant material is the most common cause found in animals transported in open trailers or kept in windy areas, leading to epiphora, blepharospasm, conjunctival hyperaemia, chemosis and eventually corneal ulceration. Single cases involving plant material (Schecter and others 1985) and the presence of Thelazia species parasites in many animals have been reported in the UK (Arbuckle and Khalil 1976, 1978). This short communication describes an outbreak of conjunctival foreign bodies in a suckler herd caused by the seed of the herbaceous weed barren brome (Anisantha sterilis) also called sterile brome, drake or haver-grass (Fig 1), present in large-bale haylage. The affected farm was an organic mixed beef, sheep, arable and poultry enterprise in Somerset. The beef herd comprised 49, mainly pedigree, south Devon spring-calving suckler cows, two bulls and 78 youngstock of various ages. Winter feeding was predominantly grass silage, but some hay and haylage was also fed. Starting in late January 2005, haylage was fed off the floor behind a feed barrier to all stock. In early February, several of the cows and youngstock were noted to have ocular discharge and signs of discomfort. Of these animals, 10 were separated and submitted for veterinary examination. Presenting clinical signs included blepharospasm, epiphora, chemosis and conjunctival hyperaemia. Foreign bodies consisting of barren brome florets (reproductive units composed of a small flower/seed encased in longer fibrous sheath [Hubbard 1968] Fig 1b) were discovered embedded in the conjunctiva at various sites around the eye (Fig 2). Varying degrees of corneal ulceration were present in most cases. Foreign bodies were removed under topical local anaesthesia (amethocaine hydrochloride 1 per cent; Minims Amethocaine; Chauvin) using fine artery forceps, and oxytetracycline (Engemycin 5 per cent; Intervet) was administered subconjunctivally. The source of the problem was immediately identified by the herd owner, who was aware that barren brome was present in the haylage. Discarding the substantial quantity remaining was not considered commercially viable, and therefore presenting the haylage further back from the feed barrier (to prevent cattle burying their heads in the forage) was implemented immediately. Four days after the initial visit, further veterinary attention was requested. The whole herd was examined; a total of 19 animals was identified with signs of keratoconjunctivitis (17 unilaterally and two bilaterally). In 13 of these, florets were identified and removed, commonly from the lateral or medial canthi or under the nictitating membrane. In many affected eyes, multiple florets were present, and in one eye, four florets were found at various locations. Three animals also had signs of reflex anterior uveitis (episcleral congestion and miosis); these were treated with systemic meloxicam (Metacam; Boehringer Ingelheim). The incidence of disease in adult animals appeared substantially lower than in youngstock. Consequently, advice was given to feed the remaining haylage only to adults. Discarding the remainder of the haylage was still not considered practical. A third visit was made to re-examine the whole herd three days later. A total of 14 animals required treatment, of which three were repeat cases. Over the following six weeks, six cases were treated in the course of four visits. Resolution was uneventful in all cases. The case details are summarised in Table 1. The control of weeds on organic pasture has been a problem since the emergence of the organic movement (Bond and Grundy 2001). Control of barren brome relies predominantly on cutting fields before the brome goes to seed (Bond and Turner 2005). Other control measures include deep cultivation (Froud-Williams and others 1984) and reseeding. In this case, barren brome had previously been seen in arable crops and on pasture on the farm; however, because the farm was organic, there was no way of removing the brome from the fields during that season because the use of herbicides was restricted. Where barren brome had been present in previous years, the fields were mown early before the brome had seeded. Unfortunately, a period of wet weather just before the fields were due to be cut in 2004 meant that grass was cut much later than originally planned. As a result large numbers of barren brome seed heads were included in the haylage. The outbreak of conjunctival foreign bodies that occurred as a consequence lasted a number of weeks and had significant costs in terms of veterinary fees, stockman time, drug costs and possibly reduced weight gains. Unfortunately, discarding the haylage and purchasing additional organic forage was not considered economically or practically viable. Veterinary Record (2006) 159, 388-389

A two-level unreplicated factorial experiment to determine the effect of organic and inorganic fertilizers on dry matter yield of permanent pasture

In organic pasture systems, the balance of soil fertility is maintained by maximizing the cycling of on-farm nutrients. In this study, the effect of fertility management on dry matter yield in organic pasture systems was examined using an unreplicated 25 factorial design. The factors were nitrogen (N), phosphorus (P), potassium (K), compost and seaweed extract, each at two levels (with [+] and without [−]). The trials were conducted in 2000 and 2001 at two fields on an organic dairy farm in Nova Scotia, Canada. The pasture mix is predominantly perennial ryegrass, orchardgrass and white clover. The fertility treatments were applied in spring, and forage yield was collected from early-, mid- and late-summer harvests. The analysis revealed the significance of several interaction effects, which varied considerably from harvest to harvest. Both +N and +Compost treatments were associated with increased yield. High levels of P and K already present in the soil either diminished or varied the effects of P and K treatments. Seaweed extract enhanced the effectiveness of N and compost, but reduced yield when used alone. The results suggest that the commonly recommended use of seaweed extract for organic pasture management can be detrimental to biomass production unless sufficient nitrogen is provided. Despite the unusually dry weather in the 2 years, the study demonstrated the applicability of unreplicated two-level factorial experiments in agricultural field studies.

Earthworm Populations and Association with Soil Parameters in Organic and Conventional Ley Pastures

ABSTRACT Earthworm density, age structure, species composition and biomass, and soil biological, chemical and physical parameters (n = 24) were compared between pairs (n = 6) of organic and conventional ley pastures on mixed cropping farms in New Zealand. No differences in population density or biomass of the earthworm species Aporrectodea caliginosa, A. trapezoides, Lumbricus rubellus or Octolasion cyaneum were detected between the paired fields. Of the soil parameters, only nitrate- N levels differed significantly between the pairs; this was higher in conventional fields. Nitrate—N levels in organic fields were significantly and negatively correlated with previous cropping intensity. The biomass of juvenile A. caliginosa was significantly correlated with some of the same parameters in the conventional and organic fields, these were anaerobically mineralizable N (AMN), bulk density and total porosity levels. The total earthworm biomass on conventional fields was positively and significantly correlated with C, N, cation exchange capacity (CEC) and macroporosity levels, and with hot water extractable C, Mg, AMN, CEC, and microbial biomass C levels, and pasture age for total earthworm density. For the organic fields, no significant association for total earthworm biomass or density with the above parameters were observed. Only the r values for bulk density and total earthworm density on conventional (-0.82) and organic (-0.80) fields were comparable. The different associations between earthworm population attributes and a number of soil biological and chemical parameters on conventional and organic fields, provides evidence for differing relationships between these soil parameters and earthworm populations in organic and conventional ley pastures.

Relationships between soil biota, nitrogen and phosphorus availability, and pasture growth under organic and conventional management

Legume-based pastures generally rely on soil biological activity to provide nitrogen (N) for plants. This study examined seasonal pasture growth in nine adjacent hill pastures, under sheep or beef, with different long-term managements, including certified organic, no fertilizer, and conventional fertilizer application, that formed a soil-fertility sequence. We determined relationships between net N mineralization, as a measure of soil biological activity and N availability, and microbial biomass, soil organic matter, and fauna. Net N mineralization generally explained differences in pasture production ( r = 0.87). On an areal basis, net N mineralization was strongly related ( r = 0.93) to total soil N (0–200 mm depth) and negatively related ( r = −0.92) to soil C:N ratio, but not to soil C. Total N and C:N ratios were related to soil phosphorus (P) status and probably past N fixation by legumes. Where labile P was low, the N:P ratios of both soil microbes and enchytraeids were wide, and the organisms appeared to be P limited, possibly competing with plants for P. Faunal grazing on soil micro-organisms appeared to release P. We could find no convincing evidence that net N mineralization, pasture growth or soil biological diversity increased under organic farming. Rather, the data from organic pastures followed similar trend lines to data from pastures under conventional management.

Influence of organic and conventional pasture management on the beta-carotene, retinol and alpha-tocopherol status of steers

In recent years there has been an increasing trend in the UK to develop low input (organic) systems for the production of agricultural commodities such as meat, milk and milk products, grains, vegetables and fruits. This trend is driven by a combination of consumer demand, environmental concerns and premium payments for such produce. There is also a consumer presumption that produce obtained ‘organically’ and animals reared under organic regimes are more natural and thus ‘better’ than products produced using more intensive systems. In the case of cattle there is evidence (Younie and Halliday, unpublished data) that animals grazed on ‘organic’ pasture perform less well and tend to be less healthy than their counterparts fed conventionally. To maintain ‘organic’ status essential micronutrients such as vitamins and minerals cannot be supplied from synthetic mineral and vitamin premixes. It is well documented that the fat soluble vitamins and their precursors are important factors in maintaining the nutritional and immune status of animals as well as the storage properties of meat. (Bendich, 1989, 1991, Ranken, 1989). The purpose of the work was to assess the fat soluble vitamin status of extensive and intensive pastures and the effect of grazing these on the blood levels in steers.