Alternative Pasture Research Articles

Use and limitations of alternative feed resources to sustain and improve reproductive performance in sheep and goats

In tropical, semi-arid, and arid areas, animal production is increasingly reliant on supplemental feeding, especially during energetically expensive reproductive seasons. The cost of many traditional feeds restricts their use in many countries, and producers are turning to alternative feed sources. These feed sources may supply the energy and protein requirements for reproduction, but can contain plant secondary compounds that affect various components of the reproductive cycle. In this article, we outline the intake requirements for reproduction in both sexes of sheep and goat, highlighting the importance of timing, as well as quantity, of supplementation on reproductive performance. We investigate examples of various alternative feedstuffs that have been studied throughout the world, such as willow cuttings, lupin seed, feed blocks, and alternative pasture species. We then review what is known about the effects of these feeds on reproduction in sheep and goats, from the well known estrogenic effects to some positive effects from feeds containing condensed tannins.

Integrating cattle into the slash-and-burn cycle on smallholdings in the Eastern Amazon, using grass-capoeira or grass-legume pastures

Abstract In the humid tropics of northern Brazil, where slash-and-burn cropping is the prevailing smallholder land use system, pastures ecologically degrade after 7–10 years of use, mostly due to invading vegetation, decline of soil fertility (N, P) and insect pests. Degraded pasture areas cannot be easily restored or returned to cropping, so large areas are abandoned. To avoid this degradation process, two alternative pastures were tested to incorporate cattle into the slash-and-burn cropping cycle. It was thought that the inclusion of secondary woody fallow vegetation, locally called capoeira, or of legumes in pastures restores the soil for a subsequent cropping phase while allowing an acceptable level of animal performance. This hypothesis was tested in a researcher-managed on-farm experiment in Igarape-Acu (Bragantina region, Para). A grass-legume pasture (GLP), combining the grass Brachiaria humidicola with three multi-purpose legumes, was compared with a pasture, where controlled regrowth of capoeira was tolerated (GCP), and tested against two controls in the form of a conventional B. humidicola pasture (GP) and undisturbed regrowth of capoeira (UC). The pastures were grazed in a rotational system for 2 years at 1.5 livestock units (LU) ha−1 in the first year and at 1.2 LU ha−1 in the following year. The results showed that the GCP kept the full regenerative potential of the capoeira, showing no significant loss of phytodiversity (GCP 67 species 100 m−2; UC 72 species 100 m−2) and low dissimilarity in species composition measured by Euclidian distance (UC/GCP = 51; UC/UC = 52; GCP/GCP = 33). On the GLP, the legumes Arachis pintoi and Cratylia argentea almost disappeared due to the grazing pressure, while Chamaecrista rotundifolia var. grandiflora was little palatable and invaded the plots by seed propagation. None of the legumes produced a meaningful quantity of nodules, and no difference in total soil N was found between GLP and the other pasture treatments. With regard to animal production, both alternative pastures were less productive than GP over 21 months of grazing (GLP = 384 kg liveweight ha−1, GCP = 474 kg ha−1, GP = 659 kg ha−1), which was attributed to overstocking in the second year. GCP was considered to be an interesting option for smallholdings, provided the balance between the vigorous regrowth of capoeira and forage grass cover can be maintained. In contrast, on GLP a more palatable Ch. rotundifolia accession would be desirable and the establishment of all legumes needs to be improved. It was concluded that GCP would support a subsequent cropping phase better than GLP. However, on both pastures stocking rates would have to be frequently adjusted a management practice that is of secondary consideration in a crop/livestock system in which cattle are kept as cash-generating assets.

Constancy in pasture composition? Empirical measurements and mathematical models

A review of 702 sets of published pasture data show there is some constancy in the relative contribution of different species in pasture, with a high linear correlation between logarithm of percentage contribution and rank of a species. The best explicit model for mathematical description of pasture composition was the geometric series. The best of the random models was the pre‐emptive function. The results are discussed in relation to the general theory of pasture composition and alternative pasture sampling techniques.

Comparison of biomass production and biological nitrogen fixation of multi-species pastures (mixed herb leys) with perennial ryegrass-white clover pasture with and without irrigation in Canterbury, New Zealand

Abstract Legume-based pastures in Australasia are predominantly perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.). These pastures have disadvantages such as limitations in the production and persistence of white clover and ryegrass in drought prone regions. With the increasing interest in organic agriculture, more complex pasture mixtures are seen as an alternative to the standard ryegrass-white clover (RWC) pasture. Although anecdotal evidence exists to support the benefits of alternative pastures, there is insufficient scientific evidence to support or refute these claims. The present study was conducted to compare three different alternative multi-species (mixed herb leys) (MSP) pastures with the standard RWC pasture with and without irrigation, in terms of biomass and biological nitrogen fixation (BNF) over a period of 1 year under field conditions in Canterbury, New Zealand. Isotopic dilution technique involving field 15N-microplots were used to measure BNF. Irrigation doubled dry matter yields (DMY) of all pastures compared with those under dryland. There was no significant difference between DMY of all pastures under dryland. However, under irrigation, MSP pastures out-yield RWC pasture in total and legume DMY. Red clover MSP produced significantly lower DMY than the comprehensive or lucerne MSP treatment, probably due to the ability of lucerne in extracting water from deeper soil depth. Seasonal changes in plant composition varied according to the species sown, soil moisture status and temperature. Total and seasonal amounts of N2 fixed followed the same trend as the DMY and were related to the DMY of legumes. On average, about 26–34 kg N was fixed per tonne of legume DMY, showing a uniformity across all pastures. Overall, based on the present results of 1-year study, the MSP pastures tend to result in higher DMY, BNF and legume growth compared with that of the RWC pasture, provided irrigation is available. With increased BNF, these irrigated MSP pastures may provide high quality feed to grazing animals.

Leaching losses of N under grazed irrigated and non-irrigated pastures

High spatial and temporal variability of nitrogen application via livestock urine on grazed pasture make meaningful measurement of leaching of nitrate very difficult. The present study was aimed at estimating the mean annual nitrogen loadings and concentrations leached to an underlying aquifer beneath unfertilized irrigated and non-irrigated paddocks of a dairy farm at OB Flat 10 km south of the city of Mount Gambier (37°50′S, 140°40′E), South Australia. Urine was collected in the milking shed and applied to 1 m deep monolith lysimeters in three separate seasons in 1992. Some lysimeters received two applications. Drainage and N fluxes and concentrations were recorded 1 year before urine application and for 3 years following urine applications. A negative binomial function was used to specify the appropriate proportions of pasture subject to 0, 1 or 2 loadings in a year, and the lysimeter drainage measurements were then scaled across seasons and paddock area to estimate mean annual leaching under the whole of each paddock. It was found that the timing of urine application had a profound effect on the leaching of nitrogen. Results indicated that the nitrate flux leaching from the root zone in the irrigated paddock was 26–33 kg N/ha/year at 13–17 mg N/litre and in the non-irrigated paddock, 10–13 kg N/ha/year at 9–11 mg N/litre. These estimates are not inconsistent with nitrate concentrations measured in groundwater but cannot be independently verified. The current transition from non-irrigated to irrigated pastures is likely to double nitrogen loads to the aquifer and cause nitrate concentrations in groundwater to exceed drinking water guidelines, unless alternative pasture management strategies are developed.

Performance of annual pasture legumes in cropping rotations in the cool temperate zone of south-eastern Australia

The relative performance of 3 alternative pasture legumes, in comparison with subterranean clover, grown in a 1:1 pasture:crop rotation was investigated during 1997–2001, at 2 sites in the high rainfall (>500 mm/year) zone of southern Australia. Seedling densities of the pasture legumes (before and after crop) were examined, along with herbage dry matter production, growth pattern and seed production. After 2 cycles of a 1:1 pasture:crop rotation, average seedling densities of balansa (Trifolium michelianum Savi var. michelianum), Persian (T. resupinatum L. var. resupinatum Gib. and Belli), arrowleaf (T. vesiculosum Savi.) and subterranean (T. subterraneum L.) clovers at the 2 sites were 6810, 2910, 680 and 630 plants/m2, respectively. Average cumulative herbage mass in 2001 was 7.49, 5.21, 8.53 and 7.76 t DM/ha.year, respectively. All clovers produced a large seed pool: balansa, 71.8 g/m2; subterranean, 38.9 g/m2; Persian, 35.5 g/m2; and arrowleaf, 35.4 g/m2. The results suggest that a 1:1 pasture:crop rotation is sustainable, in terms of pasture seed–seedling dynamics for each of the legumes, and that under this system the pasture legumes need to be sown only once.

Host range and symptomatology of Subterranean clover mottle virus in alternative pasture, forage and crop legumes

Fifty one plant species from 25 different genera in seven families were challenged with Subterranean clover mottle virus (SCMoV) by inoculation with infective sap. These included 39 legume species and 12 species belonging to the families Amaranthaceae, Apiaceae, Chenopodiaceae, Cruciferae, Cucurbitaceae and Solanaceae. Twenty one new host species belonging to eight different legume genera were found for SCMoV, nine of which were alternative annual pasture or forage species and 12 were crop legumes. Of these, seven pasture or forage species and six crop species were infected systemically. Two Chenopodium spp. were also hosts. The host status of eight previously tested legume species was also re-examined. The implications of these results for paddocks sown with alternative pasture or forage crop legumes, and for plant improvement programs evaluating such species for commercial use, are discussed.

A review of pastoral research carried out on the West Coast of the South Island: 1960-2000

The pastoral research carried out on the West Coast of the South Island between 1960 and 2000 could be divided into three categories; nutrient requirements for pasture, pasture establishment and growth and animal performance. Because of the varied fertility of the soil types present, research on nutrient requirement was the largest category. In the 1960's, requirements for pasture establishment and early growth on pakihi (podzol) soils of lime, phosphorus (P), elemental sulphur (S), potassium (K), copper (Cu) and molybdenum were identified. This work was extended to determine P, S and K maintenance requirements of pakihi, recent alluvial and brown terrace soils in the 1970's and 1980's. Elemental S was shown to be the most cost effective S fertiliser under annual rainfall greater than 2000 mm and the tetraphenyl boron (TBK) test was calibrated to measure the supply of nonexchangeable K on recent soils. A series of trials were carried out to determine pasture yield responses to fertiliser nitrogen (N) on recent soils in the early 1970's. Later work in the mid 1980's showed that measurement of accumulated soil and air temperature from early spring did not improve the accuracy in prediction of pasture yield responses to N. On the poorly drained, acid and infertile pakihi soils, the interactions between seed coating and lime were measured and the yield advantages of Maku Lotus and Yorkshire fog as alternative pasture species to ryegrass and white clover demonstrated. Rate of pasture growth trials determined the seasonal pattern of pasture production on a range of sites from 1970 to 1995. On recent soils that could not be moled, gravel moling and hump and hollowing substantially increased pasture production during a spring with high rainfall (2000 mm). In the early 1980's, dairy grazing trials showed that lengthening the grazing rotation during autumn increased winter and spring pasture production. For sheep, preferential grazing of thin ewes from weaning to mating increased overall ovulation rate. The density of sheep dung patches was shown to increase with winter stocking intensity on a pakihi soil. Surveys of dairy farm practice established an association between effectiveness of magnesium (Mg) supplementation of dairy cows and reducing the incidence of metabolic disorders. Many dose response trials established the requirement by dairy calves for selenium (Se), cobalt (Co) and Cu on different West Coast soils. Close contact between West Coast scientists, advisors and farmers ensured that local research information was efficiently communicated with a resulting high level of farmer adoption. Keywords: animal management, fertility, lime, nitrogen, pasture establishment, phosphorus, potassium, soils, South Island, sulphur, trace elements, West Coast

Bean yellow mosaic potyvirus infection of alternative annual pasture, forage, and cool season crop legumes: susceptibility, sensitivity, and seed transmission

Seven field and 5 glasshouse experiments were done during 1994–98 to determine the relative susceptibilities and sensitivities of a wide range of alternative annual pasture, forage, and crop legumes to infection with isolate MI of bean yellow mosaic virus (BYMV). Seed harvested from some species was also tested for seed transmission of the virus. Seven of 18 genotypes belonging to 17 species of annual pasture and forage legumes evaluated in 2 replicated field experiments were ranked as highly susceptible to BYMV, 7 as susceptible, 2 as moderately resistant, 1 as resistant, and 1 as highly resistant. The most susceptible and sensitive were Biserrula pelecinus, Trifolium cherleri, T. incarnatum, and T. spumosum. Ornithopus sativus was resistant but sensitive, whereas Hedysarum coronarium was highly resistant. H. coronarium was not infected when manually inoculated repeatedly with 3 different BYMV isolates. Seventy-three of the 94 genotypes of 7 crop legume species tested in the same replicated field experiments were ranked as highly susceptible, including 58/68 of Lens culinaris. Of the remaining genotypes, 6 were susceptible, 5 moderately resistant, 9 resistant, and 1 highly resistant. Five other crop legumes were included in other field experiments in which these species were ranked as highly susceptible (1) or resistant (4). Overall, the most susceptible and sensitive crop legume species were Lens culinaris (most genotypes), Lathyrus cicera, L. ochrus, and Vicia narbonensis. Lathyrus sativus (3 genotypes only), V. sativa (4 genotypes), Cicer arietinum, Pisum sativum, and V. faba were resistant to isolate MI, and Lens culinaris ILL7163 was highly resistant. When infected, C. arietinum was ranked as highly sensitive but symptoms within the other resistant crop species varied in sensitivity between genotypes. Extreme resistance was confirmed in Lens culinaris ILL7163 when it was manually and aphid-inoculated repeatedly with 3 different BYMV isolates. When testing seedlings for seed transmission of BYMV, germination on moist paper towels before testing usually proved more effective than growing in soil in the glasshouse. Low rates of seed transmission of BYMV (0.03–1%) were detected in 9 alternative pasture or forage and 3 alternative crop legume species. This is the first report of seed transmission of BYMV in these species. The pasture or forage species with the highest seed transmission rates were T. clypeatum and T. spumosum (both 1%). The crop legume species in which seed transmission was found were L. cicera (0.1%), L. sativus (0.2%), and V. sativa (0.5%). The high susceptibility and sensitivity to BYMV in some alternative annual pasture, forage, and crop legumes is a cause for concern, especially when they are intended for sowing in BYMV-prone high rainfall zones. Seed transmission of BYMV also leads to inadvertent introduction of the virus to new sites.

Modeling Nitrogen Oxide Emissions from Current and Alternative Pastures in Costa Rica

AbstractEmissions of nitrogen (N) oxide were simulated for one current, unsustainable pasture management system (Natural) and two alternative, sustainable systems (Grass‐Legume and Fertilized Improved) relevant to the Northern Atlantic Zone (NAZ) of Costa Rica. To produce frequency distributions of N oxide emissions, an expert system for generating technical coefficients of pastures was linked with a process‐based simulation model. The expert model generated parameter sets representing different options for the three management systems. The simulation model was rerun for each parameter set. Simulated nitrous oxide (N2O)‐N losses 25 yr after pasture establishment were 3 to 5 kg ha−1 yr−1 for natural pastures, 12 to 15 for grass‐legume mixtures, and 7 to 28 for fertilized grasses. Losses of nitric oxide (NO)‐N were 1 to 2 kg ha−1 yr−1 for natural pastures, 7 to 8 for grass‐legume mixtures, and 3 to 16 for fertilized grasses. Stepwise multiple regression showed that N2O‐N losses were explained by annual C input to the soil (R2 = 0.997), and NO‐N losses by attainable dry matter production (R2 = 0.972). Carbon input and dry matter production were controlled by stocking rate and fertilizer level. Soilatmosphere N oxide emissions from pastures may increase by a factor 3 to 5 when natural pastures are converted to improved pastures. Such conversion may increase the sustainability of the pasture by stopping the decline of soil N. However, the change is not necessarily sustainable from a global perspective because it increases the emission of N oxide greenhouse gases.

Economics of drought-tolerant pastures for cattle finishing on Hawkes Bay and Wairarapa hill country farms

Planting drought-tolerant pastures (tall fescue, chicory, prairie grass) is one option Hawkes Bay/ Wairarapa farmers can use to reduce the impact of drought. To evaluate this strategy two hill country sheep/beef farm models were established and entered in HerdEcon, a bioeconomics computer model. Using the two farm models, three comparisons were made: (1) base farm (no alternative pasture), (2) alternative pasture planted on 5% or 10% of grazable area, and (3) same as 2, with changes in cattle selling policy. Models were run for a 19-year sequence based on pasture growth for Hawkes Bay, and with a range of beef prices and pasture renewal costs. Drought-tolerant pastures increased the financial returns from both farm models, provided that livestock policies allowed increases in pasture quality and summer pasture growth to be captured by increased beef production. Lower pasture establishment costs and improved persistence would significantly improve profitability from drought-tolerant pastures. Keywords cattle, dryland pastures, economics

LOW-TEMPERATURE TOLERANCE OF SWITCHGRASS (Panicum virgatum L.)

Dry matter production from temperate pasture species is typically very low during midsummer. Switchgrass (Panicum virgatum L.) is being investigated as an alternative pasture species to overcome this problem. We studied two populations over 3 yr to determine if they had sufficient cold tolerance to be used in these areas. Populations selected from cv. Pathfinder were grown in plots at Ottawa and sampled from September to late November in 1985–1987. Each fall, samples were dug at intervals of 2 or 4 wk, the tops and roots trimmed back, then placed in plastic bags in a programmed freezer to determine the temperature at which 50% of the plants were killed (LT50). Percent crown moisture was also measured in the falls of 1985 and 1986. Prior to the onset of cold hardening in September, the two switchgrass populations had LT50 values of −4 °C. Slow cold-hardening occurred to the end of September, followed by a very rapid increase in cold tolerance to −18 °C at the end of October. During November, the rate of hardening decreased and cold tolerance came to a plateau of −19 to −22 °C by the end of the month. The same range has been reported for winter hardy cultivars of timothy and alfalfa. Crown moisture decreased to a plateau several weeks before LT50 values indicating that moisture is of questionable use as an indicator of cold tolerance in switchgrass. Good cold tolerance in switchgrass combined with superior survival during the severe winter of 1982/1983 and vigorous regrowth from overwintering rhizomes lead us to believe that winter hardy cultivars for central and eastern Ontario could be selected from this material.Key words: Switchgrass, Panicum virgatum L., low temperature tolerance, winter survival, forage plant

Response of Yatsyn ryegrass, Matua prairie grass and Wana cocksfoot to phosphorus and potassium

At present most pasture fertiliser recommendations are based on the nutrient requirements of perennial ryegrass. The requirements of alternative pasture species are not fully understood and fertiliser is generally applied as for perennial ryegrass. Yatsyn 1 perennial ryegrass, 'Grasslands Matua' prairie grass and 'Grasslands Wana' cocksfoot were grown in sand culture to determine their phosphorus (P) and potassium (K) requirements. Yatsyn and Matna had similar requirements for P and K while Wana required a lower level of K and more P to attain 90% of maximum yield. Magnesium levels in the herbage differed between species and decreased as K applied increased. It is concluded that further studies should be done to more accurately determine the nutrient requirements of alternative pasture species in the field so that accurate and balanced fertiliser applications can be made for alternative pasture species. Keywords phosphorus, potassium, Bromis willdenowii, Lolium perenne, Dactylis glomerata, nutrient requirements

ON-FARM INVESTIGATIVE DEVELOPMENT: A PARTNERSHIP BETWEEN FARMERS, CONSULTANTS AND SCIENTISTS

An on-farm investigative development approach is advocated and described as a relevant method to improve industry awareness and understanding of alternative pasture species and cultivars for South Island hill and high country pastoral systems and thereby improve their currently slow or sporadic rate of adoption. On-farm investigative development trials aim at effectively bridging gaps between plant breeder, agronomist, consultant and farmer. They closely integrate research objectives and extension through the establishment of large-scale experiments with pasture plants and pasture systems on farms, in close co-operation with key farmers. They are of sound experimental design and yet large enough to be defined as a production system, contributing significantly to the livestock feeding goals of the ccroperating farmer. Such trials are an integral part of the cc-operative (DSIR/MAF) Lotus corniculatus breeding programme. Three of them, each located in ,a different environmental/geographic zone, are described. Keywords: Large-scale trials, alternative pasture species, Lotus corniculatus, plant breeding/ plant selection, South Island hill and high country.

PASTURE FOR DEER PRODUCTION

Diversification in agriculture has seen the establishment of new enterprises such as deer farming. While still a small industry in absolute terms the deer industry is growing rapidly. The utilisation in situ of pasture by deer is discussed in relation to their feed requirements for two types of farming viz. weaner production and a 15 month venison stag operation. Seasonal feed requirements are poorly aligned with average pasture growth with both types of farmmg being characterised by surplus spring pasture and a deficit during summer and autumn. The primary constraint to increased on-farm production is the summer deficit. It is suggested that alternative pasture species with improved summer growth charatieristics be examined. It is also argued that earlier calving and the use of larger terminal sires could ease the pressure on summer pature and more closely align feed requirements of deer with pasture growth. Keywords: Farmed deer, red deer, pasture growth. pasture intake, feed requirements, calving date, terminal sire.

Performance and Photosensitization of Cattle Related to Forage Quality of Four Legumes1

Alfalfa (Medicago sativa L.) is a superior forage legume that has several shortcomings as a pasture species, including ruminant bloat potential. Our objective was to determine whether palatability differences among alfalfa and three nonbloat‐inducing alternative legume species would influence performance of grazing heifers (Bos taurus). Heifer performance was quantified on pure stands of the four legumes from 1982 through 1984 and of three legumes in 1985. Grazing pressure was controlled in pastures that had a Waukegan silt loam (fine‐silty over sandy, mixed, mesic Typic Hapludolls) soil. Heifers confined to cicer milkvetch (Astragalus cicer L.), by far the least palatable species, usually gained less than those confined to either alfalfa, birdsfoot trefoil (Lotus corniculatus L.), or sainfoin (Onobrychis viciifolia Scop.). Mean average daily gains during 1983 and 1984 (long‐term grazing seasons) were 0.67, 0.81, 0.80, and 0.42 kg for alfalfa, birdsfoot trefoil, sainfoin, and cicer milkvetch, respectively. Measurements of nutritive value did not explain gain differences, but reduced intake and frequent photosensitization occurred in heifers that grazed cicer milkvetch. Heifer product per hectare was influenced more by daily gains than by legume carrying capacity. Birdsfoot trefoil is a promising alternative pasture legume because it provided excellent heifer gains and had better summer growth and persistence than sainfoin, although somewhat less persistence than alfalfa. The poor palatability of cicer milkvetch was associated with reduced intake, reduced gains by cattle, and possibly with the photosensitization problem; however, its excellent yield, persistence, and nutritive value indicate that cicer milkvetch deserves more research and breeding to overcome its antiquality traits.

Infection studies with Cercospora zebrina on pasture legumes in Western Australia

The effects of inoculum level, and temperature and humidity regimes on the development of Cercospora blackstem disease (caused by Cercospora zebrina) in subterranean clover (Trifolium subterraneum) were investigated. Mycelial fragments were an effective and reliable inoculum. The incidence, severity, and the rate of disease development increased with increasing period of high humidity after inoculation and with increasing concentrations of inoculum. Disease was greatest at 18/13� (12/12 h, day/ night), followed by 21/16�C, and then l5/10�C While all cultivars of T. subterraneum sprayed with hyphal fragments of C. zebrina became infected, Trikkala and Larisa showed some resistance. Of the alternative pasture legumes, lucerne (Medicago sativa), medic (M. littoralis, M. truncatula), drooping-flowered clover (T. cernuum), strawberry clover (T. fragiferum), rose clover (T. hirtum) and white clover (T. repens) were all susceptible; only serradella (Ornithopus compressus) was resistant.

Production of two species and two interspecific hybrids of phalaris under irrigation in south-west New South Wales

Two phalaris hybrids (Siro 11 46 and allopolyploid) and the parent lines (Phalaris aquatica and P. arundinacea) were compared in monoculture with nitrogen fertilizer and in a mixed sward with white clover and lucerne. The experiment was flood irrigated and the effects of defoliating the swards at intervals of 21, 42 and 84 days were measured. The hybrid (Siro 11 46) was the most productive genotype at all defoliation intervals. Eighty one % of its annual yield occurred in spring and summer. This production imbalance renders Siro 11 46 unsuitable as the foundation of a pasture for high production throughout the year. The mixed sward produced more than the monoculture sward when defoliated every 21 or 42 days and there was increased production associated with increased defoliation interval. The monoculture sward was more productive than the mixed sward at an 84 day defoliation interval. The yield of Siro 1146 + white clover was 2.25 t ha-1 per 84 days, compared with a mean yield of phalaris + white clover of 1.78 t ha-1 per 84 days for the three other genotypes. The results indicate that Siro 11 46 grown with white clover and defoliated approximately every 42 days would be a suitable alternative pasture to Paspalum dilatatum and white clover in the two-pasture system used in irrigation areas of southern New South Wales. The problems of low acceptability and suspected toxicity of Siro 1146 are discussed.

Cobalt Deficiency in Sligo

On a farm on sandy soil in Co. Sligo where sheep pine and die, and cattle show pronounced ill-health, the administration of cobalt to the stock restores-health and increases productivity to a remarkable degree. The herbage is definitely deficient in cobalt. The stock on this particular farm are confined to it, while the stock from neighbouring farms in which the pronounced cobalt deficiency symptoms do not appear have alternative pastures.