As the effectiveness of current anthelmintic drenches is being reduced by the emergence of drench resistance and significant production losses may still occur as a result of continuing larval challenge, strategies for nematode control should focus on preventing the build-up of infective larvae on pasture rather than treating the infection. This paper reports the effects of condensed tannins (CT) extracted from Lotus pedunculatus, Lotus corniculatus, sulla (Hedysarum coronarium) and sainfoin (Onobrychus viciifolia) on in vitro viability of eggs, first stage larvae (L1) and third stage larvae (L3) of the sheep nematode, Trichostrongylus colubriformis. When in vitro assays contained CT in a similar concentrations to that in the digestive tract of sheep fed these forages, the CT reduced the development of eggs to L3 larvae as well as the proportion of eggs hatching. The CT also reduced the development of L1 larvae to L3 larvae and decreased the motility of L3 larvae when assessed by the larval migration inhibition assay and this may reduce their infective capacity in vivo. If these forages are fed to grazing sheep, then it may be possible to reduce contamination of pasture with infective larvae and reduce our dependence on anthelmintics as the principal method for controlling internal parasites. Keywords: condensed tannins, drench resistance, egg hatching, larval development, Lotus, parasites, sainfoin, sulla, Trichostrongylus colubriformis
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(217 KB)Dags represent a major cost to sheep farmers, in both monetary terms and because of the stress associated with flystrike. Historically, the incidence of dags has been attributed in large part to worm burdens, but other causes may be more important, viz parasite larval challenge, fungal endophyte and selection of sheep for resistance to worms. These and other factors associated with the incidence of dags are summarised, together with variations in faecal types (physical and chemical composition) which affect their capacity for adhesion to wool. Much of these data emphasise the importance of differences or changes in intestinal function being responsible for the loose and gooey faeces which develop into dags. Flystrike is strongly correlated with dags, and this scenario cannot be tolerated in a country claiming to produce good, clean food. Keywords: dags, diarrhoea, endophyte, faeces, flystrike, parasitism, sheep
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(183 KB)During 1997/98, a postal survey of 100 sheep and beef pastoral farms asked the farmers a range of questions based around pasture performance and their perceptions on persistence, and asked them to identify a persistent paddock on their farm. The farmers were then interviewed on the management of the chosen persistent paddock and the paddock was assessed for composition and fertility. The farmers ranked pasture species persistence fourth, behind pasture quality, animal health, and soil fertility in terms of importance to the whole farm system. The difference was significant between pasture quality and pasture persistence. The persistent pastures, as identified by the farmers, had high levels of desirable species and low levels of weeds and low-fertility volunteer species. The survey showed some pastures can persist and maintain high levels of desirable species for periods over 21 years. Fertility is a key factor in pasture persistence followed by drainage and grazing management. Keywords: farm management, farm survey, farmers’ perceptions, interview, pasture persistence, species composition, soil fertility
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(175 KB)Substantial genetic gains have been achieved across a range of temperate forage grass and legume species in New Zealand during the past 60 years. The genetic gains reported here compare favourably with those achieved in cereals and with those achieved for similar species internationally. Substantial improvements in grain yield of cereal crops have been achieved through changes in harvest index; however, increases in yield of forage grasses and legumes reflect increases in total above ground biomass. Rates of genetic gain have been lower in lucerne (Medicago sativa L.) than in red clover (Trifolium pratense L.) and white clover (Trifolium repens L.) and lower in perennial ryegrass (Lolium perenne L.) than in annual ryegrass (Lolium multiflorum Lam.) and tall fescue (Festuca arundinacea Schreb.). Gains in forage yield and quality have often exceeded 1% per year and have led to significant (0.3 to 1.3% per year) increases in animal performance. Keywords: animal performance, forages, genetic improvement, quality, symbiotic associations, yield
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(179 KB)Farmers can choose between investment in pasture species or fertiliser, however, there are few comparisons of these options. This paper reports on the effects of ‘Grasslands Wana’ cocksfoot, (Dactylis glomerata L.) introduction and superphosphate application on pasture production in hill country. The effects of pasture production on bullbeef production were subsequently modelled using Stockpol®. Pasture, bull and financial performance was measured within four self-contained farmlets (each approximately 9 ha) at the AgResearch Ballantrae Hill Country Research Station; half of two farmlets had been oversown with Wana in autumn 1992 and two farmlets were untreated “Resident” hill pasture. The Wana farmlets generated an average $42.80/ha greater income than Resident farmlets. On average, modelling with Stockpol found gross financial return was increased by 80% by application of 40 kgP/ha ($715.26/ha) compared to nil fertiliser ($397.84/ha). With a cost of fertiliser of $2.44/kgP applied ($97.60) this predicted return was highly profitable. If the establishment costs of Wana were spread over the life of the pasture economic responses would be greater from investment in Wana cocksfoot, however, in the short term, economic responses were greater from investment in fertiliser. In the medium term a combination of investment in Wana establishment and fertiliser input would likely maximise the economic return. Keywords: bull beef, Dactylis glomerata L., farm system, ‘Grasslands Wana’ cocksfoot, Stockpol®, superphosphate
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(164 KB)Liveweight changes were measured for lambs grazing six high endophyte perennial ryegrasses, in a grazing experiment run by an independent research organisation in Canterbury, New Zealand. Ryegrass cultivars were sown under code in a binary mix with white clover in February 1997. Plots were strategically irrigated to avoid moisture stress, and stocked at approximately 27 Coopworth ewe lambs per ha in May 1997. Common pasture residual mass was maintained across cultivars by strategic addition of extra lambs, with extra grazing days recorded for each replicate. Lamb liveweight gains and botanical composition of replicates were assessed quarterly. Lamb liveweight gains differed significantly between treatments in Years 1 and 2 of this ongoing 3 year study. Lambs grazing ‘Quartet’ tetraploid perennial ryegrass gained, on average, 37.4 kg and 36.1 kg liveweight during Years 1 and 2 respectively, and together with ‘Aries HD’ (35.0 and 35.9 kg) produced significantly greater liveweight gain compared with ‘Grasslands Nui’ (22.0 and 23.7 kg) and ‘Bronsyn’ (22.5 and 24.1 kg), LSD0.05 = 6.0 and 7.4. Lambs grazing ‘Embassy’ gained 31.6 kg and 28.7 kg, and ‘Vedette’ 29.8 kg and 28.0 kg. Extra grazing days expressed as a percentage of base grazing days were between 3.8 and 6.7% across cultivars for Year 1 and between 2.0 and 6.5% across cultivars for Year 2. This study demonstrated significant differences in animal productivity between perennial ryegrass cultivars that produce comparable yields of dry matter. Differences may reflect variation in forage quality, endophyte toxins, clover content in the sward or other unidentified cultivar characteristics. Keywords: digestibility, endophyte, lamb, liveweight, perennial ryegrass, tetraploid
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(179 KB)Ectoparasites of sheep, principally blowflies and lice, cost the New Zealand farming industry an estimated $60 million each year. This figure includes the cost of chemicals and labour used to treat or prevent flystrike and lice, together with the lost production. An Integrated Pest Management (IPM) trial project involving four groups of farmers (overall total 15) in four regions of New Zealand has been set up with the aim of adopting a holistic approach to managing these parasites and already early benefits have accrued to the farmers involved. Procedures were set up to reduce insecticide residues in wool by using techniques such as jetting which apply less chemical to the sheep but target it more appropriately and maintain or improve protection against flystrike and control of lice. As a consequence, savings in chemical and labour costs have been made. On two farms in particular, savings on these items ranged from $578 (27% reduction) on a property with 2000 Corriedale ewes to $3608 (52% reduction) on the other property with 8000 Romney ewes. An understanding that clean, healthy sheep, free of nematodes and dags, are less susceptible to flystrike and lice has also assisted in controlling the diseases. This paper also discusses the potential for biological control against blowfly populations, with large fly traps, sterilising baits and parasitoid wasps all being investigated. Research continues on specialist pastures such as birdsfoot trefoil (Lotus corniculatus) and sulla (Hedysarum coronarium) to evaluate the practicalities of incorporating their use in management systems for both nematode and flystrike control. Keywords: biological control, blowflies, flystrike, insecticides, IPM, lice, pasture varieties, sheep
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(159 KB)(23 g condensed tannins (CT) /kg DM) and perennial ryegrass–white clover pasture (1 g CT/ kg DM) during the late summer/autumn of 1997 (Experiment 1) and 1998 (Experiment 2). Ewes were in thin condition and weighed 54 kg in Experiment 1 and were fat and weighed 60 kg in Experiment 2. Oestrus was synchronised for two cycles in Experiment 1 and four cycles in Experiment 2. Ewes were grazed at maintenance for the first 10 days of each oestrus cycle and then ad libitum for the last 6 days, including ovulation. Half the ewes grazing L. corniculatus were drenched twice daily with polyethylene glycol (PEG), to inactivate the condensed tannins. Relative to ewes grazing pasture, grazing ewes on L. corniculatus increased both ovulation rate (OR) and wool production, with the response in OR being greater in Experiment 1 (34%) than in Experiment 2 (13%). Maximum increase in OR occurred after grazing lotus for two cycles (5 weeks). Increases in fecundity were caused by a reduction in the proportion of ewes exhibiting single ovulation and increases in the proportions having doubled and triple or quadruple ovulations. As judged by responses to PEG supplementation, part of the L. corniculatus response in OR could be explained by action of CT in Experiment 1 but not in Experiment 2. As voluntary feed intake was similar between the treatments, feeding L. corniculatus improved the efficiency with which ingested nutrients were used for reproduction and wool growth. It was concluded that grazing L. corniculatus during autumn has most potential for increasing OR in lighter ewes. Keywords: condensed tannin, forage, Lotus corniculatus, nutritive value, ovulation rate, wool growth Abbreviations
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(175 KB)The effects of two contrasting forage supply options on forage and sheep production were evaluated on unirrigated farmlet systems at Winchmore, Mid-Canterbury. One option was based on perennial ryegrass pastures (Control), and the other (Improved) on hybrid ryegrass, tall fescue, and chicory pastures. All pasture types grew at similar low rates during winter but chicory grew more rapidly than the grasses during the summer droughts. The Control conserved more but required less conserved feed than the Improved system. Both had a feed deficit which averaged 23 and 42 kg DM/ewe respectively over the 2 years. The lambs on the Improved pastures grew more rapidly than the Controls throughout, exceeding the rate of the Controls by 142 and 165 g/head/day post-weaning in years 1 and 2 respectively. This resulted in considerably more lambs reaching target drafting weights on the Improved system, 92 vs. 53 and 97 vs. 58%, in years 1 and 2 respectively. This increased the income from lambs by $104 and $94/ ha in these years. Ewe liveweights were similar during pregnancy but differed during lactation and post-weaning at the end of which, ewes on Improved pastures were 6 and 4 kg heavier than the Controls in years 1 and 2 respectively. They consequently produced fleeces that were 10 and 12% heavier. The superior animal performance associated with the Improved system reflects higher pasture quality due to less endophyte and dead matter, and an increase in the proportion of the more nutritious components, legumes and chicory. Keywords: dryland, lamb production, pasture production, pasture quality, pasture species
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(176 KB)
Farmers have a far reaching impact in influencing the progress that is made in the sustainable management of New Zealand’s natural resources. While some advocates are ready and willing to prescribe apparently “more appropriate” behaviour, the contribution to sustainability can be questioned. There is considerable evidence that there is a complex interaction between farmers’ knowledge, attitude and behaviour, and economic, personal and community influences that shape the nature and extent of their individual response to the challenge of sustainable resource management. This paper will draw on the experience of working with farmers and community members in the Southern North Island to develop an approach to allow land users to better understand the soil and water resources of the farm. By using this knowledge, and their awareness of issues and values, farmers and community members were better able to consider options, evaluate alternatives, and balance the integration of sustainable resource management, economic, personal and social goals. A strong conclusion of the project was that farmers must have a comprehensive understanding of the soils and land resource of their farm. A feature of the project was the development of the concept of Land Management Units (LMUs) that are aggregations of soil or topographic units with closely related properties that form a practical farm management unit. LMUs provide the basis for evaluating the impact of current policies and management practice, generating ideas, evaluating risk, and developing options that are potentially more sustainable. The process of adopting LMUs is presented and discussed as the basis from which to evaluate the sustainability of land use practices. Keywords: environment, extension, farm management, land management units, land use, soil, survey, sustainability
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(168 KB)Blood selenium concentrations and liveweight gains were assessed for sheep grazing pastures treated with different selenium supplements over a 2-year period. Three 0.5 hectare irrigated blocks with pasture selenium concentrations of less than 0.04 μg/g DM were identified near Lincoln, Canterbury during 1997. Treatments applied in early November 1997 were: (1) 1 kg/ha of an experimental selenium product (SRSe5, containing 10g selenium); (2) 1 kg/ha of a commercially available slow release selenium product (positive control, containing 10g selenium) and (3) nil selenium treatment (negative control); all treatments used 60 kg urea/ha as the carrier. Treatments were stocked at 30 lambs/ha in November 1997. Liveweight gains and concentrations of blood selenium were monitored fortnightly for the first 4 months of the study and monthly thereafter. Following mating in April 1998, blood selenium concentrations and liveweight gains of spring born progeny were assessed. Ewes grazing the SRSe5 and positive control treatments had significantly greater concentrations of blood selenium than the negative control group and the concentrations for the SRSe5 group were significantly greater than from the positive control. Negative control ewes and their lambs were removed from the study at lambing due to low blood selenium concentrations and concerns regarding their health. Concentrations of blood selenium did not differ significantly between lambs of SRSe5 and positive control ewes born in the second year of the study. Lamb and ewe blood selenium concentrations were highly correlated. Liveweight gains did not differ significantly between SRSe5, positive control or negative control groups for ewes or lambs during either year of the study. This study demonstrated that the application of selenium to pastures is a highly effective longterm strategy by which concentrations of blood selenium may be elevated in sheep under New Zealand pastoral conditions. While liveweights did not differ significantly between treatments during either year of the study, the small numbers of animals used limited the power with which differences could be detected between treatments. Keywords: pasture, selenium, sheep, supplementation, topdressing
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(174 KB)Seasonal changes in herbage elements (Cu, Mo, S, Fe), pasture growth, and soil moisture were measured and their relationships with liver Cu concentration in weaner heifers (n=10–12) and breeding cows (n=10–12) were determined on 7 commercial farms in the Wairoa region. Liver biopsy samples were collected at 2 to 4 monthly intervals and herbage and soil moisture monthly from spring 1996 to spring 1998. Mean Mo concentration of herbage offered to cattle on the 7 farms ranged from 0.7 to 3.2 mg Mo/kgDM and Cu herbage concentrations from 5.7 to 10.5 mg Cu/kgDM. Mean concentrations of Cu in cattle livers ranged from 85 to 204 μmol Cu/kgFW across farms. Herbage Cu, S and Fe concentrations were highly seasonal with low levels in late spring– summer and high levels in autumn and winter. In contrast, herbage Mo was less seasonal. There was a suggestion that variation in liver Cu across seasons was positively affected by increasing herbage Cu concentration and negatively affected by increasing herbage S concentration and unaffected by herbage Mo concentration. Over the two years 46% of non- Cu supplemented cows and 32% of weaners had deficient (<95 μmol Cu/kgFW) liver Cu levels but clinical signs of Cu deficiency were not observed. Weaner liver Cu concentrations were low in summer and autumn (126 μmol/kgFW) but repleted over the winter and spring seasons (195 and 237 μmol/kgFW respectively). Cows had highest levels of liver Cu in summer (147 μmol/kgFW) but these fell steadily over winter to reach low (62 μmol Cu/ kgFW) levels in spring before calving. The study supports the conclusion of Korte (1995) that in the Wairoa region herbage Mo may impair absorption of Cu in cattle grazing pasture with Mo levels as low as 0.5 mg/kgDM, but once herbage Mo rises above 2 mg/kgDM then further reduction in Cu absorption is minimal. Keywords: copper, cows, herbage composition, herbage minerals, liver, molybdenum, season, soil moisture, weaners
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(164 KB)Measurements of soil phosphate, pasture production and botanical composition from two superphosphate fertiliser trials in northern North Island hill country (Whatawhata and Te Kuiti) have been made over a 15-year period. The impacts of superphosphate fertiliser withholding have included a decline in Olsen P, decreases in annual pasture production of 10–17% (Whatawhata) and 22–42% (Te Kuiti), decreases in the abundance of productive and desirable species (15–20% for ryegrass and white clover), and increases in the abundance of undesirable species (browntop and other low fertility grasses). These changes have increased over time, beyond that period covered by the original experiments (4–6 years). Different responses to withholding between the two sites are still apparent, and the reasons for these are explored. It is not clear that these systems have yet reached a new equilibrium, nor how long it will take for this to happen. The implications for our view of longterm grassland studies are discussed. Keywords: fertiliser, long-term, pasture production, pasture species composition
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(171 KB)The view of the presenters of this paper is that more trees need to be integrated into New Zealand farming systems. This is particularly relevant to some 3.7 million ha of North Island hill lands that require significant soil conservation measures. Trees have numerous benefits beyond soil conservation and these are outlined. The simplest and most effective means of implementing a large scale strategy of tree planting on land dominated by livestock farming enterprises is likely to be through the use of wide-spaced tended poplars. It is our perception that the full range of benefits (and costs) is not well appreciated within the industry, and so we have attempted to summarise and discuss them here. We have adopted the perspective of the individual farmer, who in the end is the one who will determine the role of trees in the rural landscape. Keywords: conservation, hill country farming, landscape, poplar, silvopastoralism, soil conservation
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(129 KB)
A farmlet study was carried out over 2 years to examine the role of milk production in dryland lamb production systems. Poll Dorset ewes (high milk producers) were mated with Romney rams and Romney ewes (average milk producers) were mated with Poll Dorset rams to produce lambs of a similar genotype. As well as two levels of milk production, two fecundity treatments were used and farmlets were replicated. Farmlets were 2.9 ha and stocked at a rate of 15 ewes/ha. Farmlets were managed to ensure similar pasture covers at the start of winter and at lambing. Poll Dorset ewes produced more milk and in both years their twin lambs had a small but significant advantage in lamb growth rate. This resulted in earlier drafting of lambs and the ability to obtain early season premiums. In the low fecundity farmlets, net financial returns for Romney and Poll Dorset ewes were $605/ha and $676/ha (+ 12%) in Year 1 and $709/ ha and $762/ha (+ 7%) in Year 2. For the high fecundity farmlets, financial returns for Romney and Poll Dorset ewes were $637/ha and $818/ha (+ 28%) in Year 1 and $866/ha and $921/ha (+ 6%) in Year 2. The greatest financial benefits to increased milk production were achieved in high fecundity ewes in Year 1 when feeding during lactation was less than optimal and this resulted in a significant effect on the rate at which twin lambs were drafted to achieve early season premiums. Lambs failing to reach minimum drafting weights were also penalised because of the prevailing drought conditions and low market prices for lighter lambs. Keywords: breed, dryland, ewes, farming systems, fecundity, milk production, pre-weaning growth, profitability, sheep
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(162 KB)The climate is very conducive to an early lambing programme as our mild winters allow some grass growth resulting in good lamb growth rates. Marks and Spencer criteria are tight, so strict drafting procedures are essential. Only a high qualifying percentage will result in high per head dollar values. Early sale of Marks and Spencer lambs is complimentary to other farming operations and allows greater flexibility with seasonal extremes. The early lambing operation is geared basically 100 for 12 weeks of production from the time when lambs hit the ground to their sale. If the majority of early-born singles do not meet the contract, then the whole procedure is a waste of time and resources.
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(100 KB)High-value consumer markets are demanding a continuously higher quality of products and enhanced food safety. In association with this, the increasingly competitive global market place and developments in information technology have catalysed the establishment of closer relationships and co-operation between participants in high-value supply chains. These closer relationships enhance the flow of information between participants and their ability to introduce strategies to improve efficiencies in supply as well as to decrease risks to consumers and others in the supply chain. These trends have significant implications to New Zealand farmers who will need to adopt systems to more effectively monitor and record their use of inputs and subsequent farm and stock management and make this information available to those further down the value chain. An inability to respond to these trends may result in farmers as well as processors, limited to servicing only relatively lower value markets. Keywords: agricultural sector, information technology, New Zealand, supply chain integration, supply chain management
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(157 KB)What do we mean when we talk about Farming to Specification? As a farmer, I take that to mean supplying a product that has been farmed to required Quality Assurance Standards and presented to a processor on time, in full and to market specification. Processing and marketing companies have started to demand tighter guidelines for product supplied and there is no doubt in my mind that the tightening trend will continue. We already have a number of companies offering fixed price and grade contracts, with severe penalties for non-supply, and I am sure that these contracts will become commonplace within the Sheep, Beef and Deer industries. Our major customers in overseas markets are demanding guaranteed and consistent supply year round. The main threat that we face in our ability to supply product to specification is the climate and the influence it has on pasture production and animal performance. It is imperative that we have systems in place to take full advantage of opportunities when the climate is favourable, but also when the climate is challenging. My paper today will focus on the systems we have developed that enhance our ability to farm to market specification for sheep beef and deer.
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(100 KB)Shearing ewes in mid pregnancy can provide farmers with management and financial advantages. Six experiments conducted at Massey University have collectively shown that shearing ewes at this time can increase lamb birthweight by up to 1.0 kg. When comparisons were made across studies, there was a strong negative relationship between size of the response and the birthweight of control lambs (those from unshorn ewes). The best time to shear ewes to gain a maximum response is likely to be pregnancy day 50 to 100. In a large field trial involving 1002 twin-born lambs, there was a 3% reduction in mortality rate in lambs born to ewes shorn at pregnancy day 67 compared with those lambs born to unshorn ewes (i.e., mortality rates of 15 vs 18%). Pre-lamb shearing offers real advantages to farmers wishing to increase lamb survival at birth. Keywords: ewes, lamb birthweight, lamb mortality, mid-pregnancy shearing
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(165 KB)
Management strategies to control Chilean needle grass comprised two re-grassing regimes using the competitive pasture species cocksfoot, combined with lax grazing using sheep or young cattle, no attempted management, and forestry. The presence of Chilean needle grass and cocksfoot densities were assessed by examining 50 mm turf cores taken annually from 1994, and from the forestry site since 1997. There was a strong inverse relationship between Chilean needle grass frequency of occurrence and the sown cocksfoot density. The establishment of cocksfoot and its promotion by lax grazing reduced the frequency of occurrence of Chilean needle grass from 60% in October 1994 to 9% in 1998. Although cocksfoot suppressed Chilean needle grass, eradication appears unlikely or at least a long-time process. In the young pine plantation, Chilean needle grass grew unchecked with 24 and 27% of the cores containing Chilean needle grass in 1997 and 1998 respectively. Under forestry the Chilean needle grass seed bank is likely to develop until canopy closure. Keywords: Chilean needle grass, cocksfoot, Dactylis glomerata, forestry, grazing, Pinus radiata, Stipa neesiana, weed control
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(167 KB)Climate variability has a significant impact on climate sensitive industries in New Zealand, including farming. Droughts, floods, and other extreme or unseasonable weather events all have an impact on primary production, and ultimately, profitability. NIWA has recently established the National Climate Centre to improve the flow of climate information to climate sensitive industries, including the farmer. The Centre’s goal is to help New Zealanders manage for climate variations, by providing accessible, easy to understand, climate information. This paper will provide details about some of the basic NIWA National Climate Centre climate information that is available, and how to access it. Keywords: climate, El Niño, forecasting, La Niña, risk management, weather
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(123 KB)Commercialisation of genetically modified organisms creates new challenges for marketers and developers of this technology. The cost of development is high, and the need to gain a return on investment that reflects this cost is critical to ensure that this technology is brought to New Zealand agriculture. A further challenge is that the regulatory requirements differ from those required for non-transgenic crops. Once introduced into the market, it is important to develop a product stewardship programme to ensure continued trait performance and prevent factors arising that will negate the value of these traits such as pest resistance. Keywords: genetically modified organisms, market analysis, product stewardship, regulatory process, return on investment
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(102 KB)A greenhouse pot trial was conducted to investigate the effect of addition of amino acids and casein to Cu fertilisers on Cu uptake by chicory (Cichorium intybus L. cv. Grasslands Puna) plants. Irrespective of the forms and rates of Cu applied, the addition of amino acids and casein had no significant effects on chicory shoot dry weight. CuSO4 resulted in significantly higher shoot Cu accumulation than Cu(OH)2. Addition of histidine (His), methionine (Met), aspartic acid (Asp) and casein to Cu(OH)2 significantly increased Cu uptake at 100 mg Cu/kg soil treatments. Total accumulation of Cu from casein + Cu was significantly higher than from Met + Cu and Cu alone at 50 mg Cu as CuSO4/kg soil treatments. At the rate of 100 mg Cu as CuSO4/kg soil, the addition of His and casein resulted in significantly higher total shoot Cu accumulation than the addition of Met, Asp and CuSO4 alone. When Cu was supplied as Cu(OH)2, addition of His, Met, Asp and casein increased Cu uptake by 2.86–8.85, 3.81–6.19, 3.81–12.39 and 9.52– 15.04% respectively. The corresponding values for CuSO4 with the addition of His, Met, Asp and casein were 10.88–14.60, 4.08–4.32, 3.24–6.80 and 20.41–21.08% respectively. These results suggest that the addition of amino acids or casein to Cu fertilisers can increase chicory Cu uptake, but the agronomic value of the mixtures needs further investigation. Keywords: additives, amino acids, casein, chicory (Cichorium intybus L), copper fertilisers, copper uptake
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(191 KB)Efficient livestock production from pasture requires an understanding of preference and selection by grazing animals. Selective grazing influences diet not just in the short-term but more importantly, in the long-term through its affect on pasture composition. This paper summarises techniques developed to explore the nutritional basis for preference in complementary indoor and field studies. Indoors, sheep in metabolism crates were offered ryegrass and white clover in separate feed bins. Voluntary intake and eating behaviour were recorded, and following a period of free choice to establish preference, an intra-ruminal infusion of ammonia was given when sheep ate clover. We hypothesised that sheep given additional ammonia with clover would alter selection toward grass as a means of reducing the input of this metabolite from the rumen to the blood stream. When offered a choice, sheep selected a diet comprising 70–85% clover and 15–30% grass. Infusion of ammonia did not affect the proportion of grass or clover selected, but it reduced feed intake by about 15%. In field studies, each of 12 rumen-fistulated sheep was fitted with a harness carrying a remotecontrolled infusion pump and a pack of either water or a urea solution for infusion during grazing. Urea, as a rumen-ammonia precursor, was infused only during periods of eating. Sheep were offered either grass alone or clover alone and infused with urea or water over 4 days to create an association between eating that species and elevated ammonia load. The sheep were then offered a choice between adjacent monocultures of ryegrass and clover for 2 days to test preference and were infused only when the background species was selected. The sheep from the clover background responded to elevated rumen ammonia. They reduced grazing time on both clover alone (275 mins grazing/day when infused with urea vs 325 mins/day for water controls), and when they had a choice between grass and clover (425 vs 490 mins/day for urea infused and control sheep, respectively). These techniques provide novel opportunities for identifying the roles of plant nutrients in preference and ways these might be manipulated to control diet selection and intake. This paper describes the methods used, and gives preliminary results of trials with clover and grass using ammonia compounds. Keywords: clover, diet selection, grass, nutritional basis, preference, sheep
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(163 KB)The first transgenic animals were produced back in the mid-80s. This involved the introduction of foreign DNA into fertilised mouse eggs producing transgenic mice for studies of the biological systems regulating growth and development. Since that time, transgenic mice, rats, rabbits, sheep, pigs, goats and cattle have been produced. The use of transgenic animals for novel biomedical applications, such as the production of biologically important molecules or therapeutics, has now progressed to near-commercialisation. With the biological revelation that a cell taken from an adult animal can be developmentally-reprogrammed and, following transfer to an enucleated egg, produce a copy of the original donor animal came a new approach to the production of transgenic animals. This procedure, commonly referred to as nuclear transfer or ‘cloning’ now provides a new exciting and more sophisticated approach to the production of transgenic animals. These technologies and the livestock produced will have a significant impact on agriculture, livestock production, medicine and society as a whole. The current debate in our society about genetic engineering and genetically modified foods is indicative of the need to carefully identify the issues, and fully assess the benefits relative to the risks before embarking on commercial transgenic livestock production. Keywords: biotechnology, cattle, genes, microinjection, molecular biology, nuclear transfer, nutraceuticals, pharmaceuticals, sheep, transgenic livestock
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(495 KB)Mowing pasture before grazing, and topping pasture after grazing were studied as methods to increase pasture quality, dairy cow dry matter intake, and milksolids production from September 1997 to February 1998. Three 2.8-ha experimental areas were subjected to mowing, topping, or control treatments, and were grazed by three Friesian cows/ha (18 cows per treatment). Cows were allocated to each treatment according to a crossover design and pastures were grazed every 28 days. Mowing pasture, either before or after grazing, reduced pasture production by 20%, and reduced milksolids production by 11% during October, but increased milksolids production by 12% during summer. Liveweight change responded similarly; mowing or topping resulted in greater liveweight gain (0.76 kg/cow/day) during summer compared with the control. This was associated with an increase in the metabolisable energy content of summer pastures that had been mown before grazing (0.2 MJME/kg DM), or topped after grazing (0.6 MJME/kg DM). Topping pastures after grazing reduced milksolids production in October by 0.11 kg MS/cow/day, and increased milksolids production in summer by 0.13 kg MS/cow/day. Mowing pasture before grazing increased average dry matter content of the wilted material by 7.5% units compared with the control, but dry matter intake was reduced by 2.4 kg DM/cow/day in November, and milksolids production was reduced by 0.12 kg MS/cow/day during spring. Mowing before grazing increased milksolids production in summer by 0.13 kg MS/cow/day. Overall, only the topping treatment increased total milksolids produced during the six 14-day experimental periods (by 80 kg MS, or 4.6%). However, an additional 5184 kg of DM was removed from the control pastures by extra cows, which could have produced an additional 415 kg milksolids. Therefore, although mowing or topping can increase the quality of pasture and the yield of MS per cow in summer, the overall benefits for MS production per ha are small or negative. Keywords: dairy cow, herbage mass, milksolids, milk yield, mowing, nutritive value, pasture intake, topping
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(165 KB)This paper describes analysis by near infrared reflectance spectroscopy (NIRS) and demonstrates the capacity of this technology to provide rapid, low cost and accurate estimates of feed composition. The need for an extensive database against which the instruments is calibrated and the importance of good wet chemistry backup to NIRS are emphasised, together with some of the diverse uses for NIRS in research and agriculture. Examples are given of contrasting analyses for quality of maize silage and pastures. NIRS prediction of pasture, silage and supplement composition can be used in conjunction with a ration balancing model developed for the New Zealand dairy industry, allowing farmers to formulate diets able to meet desired levels of production. Keywords: dairy, feed quality, forage analysis, NIRS, nutrition
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(204 KB)In recent years, the number of pasture species and cultivars commercially available to farmers in New Zealand has increased significantly. Reasons for this include increased commercial activity in the development and supply of proprietary cultivars, and more specialisation in New Zealand’s pastoral agriculture. In particular, pasture cultivars are increasingly marketed as proprietary products with associated technical support. This year there are 109 certified cultivars available, belonging to 23 grass, legume and herb species. As a result, farmers are now able to develop improved pasture feed supply, but they are somewhat confused about pasture species and cultivars, and this frustrates their aims to produce high quality animal products from productive pastures. Accordingly, the herbage seeds industry needs to work from a clear reference list, to avoid any confusion when supplying farmers and overseas clients with their seed requirements. Our list of pasture species, types and cultivars available within New Zealand aims to be that reference. Keywords: birdsfoot trefoil, brome grass, caucasian clover, chicory, clover, cocksfoot, cultivars, herbs, lotus, lucerne, pasture, phalaris, plantain, prairie grass, red clover, ryegrass, seeds, species, strawberry clover, sub clover, tall fescue, timothy, types, white clover, Yorkshire fog
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(221 KB)Tiller number, survival and development were determined in clover-free swards of Aries HD and Yatsyn 1 high-endophyte perennial ryegrass established in the autumn of 1995 and continuously stocked with sheep. Few tillers died until mid December, after which survival approximated an exponential decay curve. There was no difference in the rate of tiller death between Aries HD and Yatsyn 1 swards. Seedheads were first observed on 19 November 1996 and were still visible on 26 March 1997. Aries HD appeared to have a greater proportion of initial reproductive tillers, but after mid-December a lower proportion than Yatsyn 1. There was an indication that Aries HD swards had a higher density of lighter tillers than Yatsyn 1. In a second experiment established in the autumn of 1997 rotationally grazed with sheep, Aries HD appeared to have a greater proportion of vegetative tillers during November and December, and greater mean ryegrass tiller density. Marginal differences in reproductive behaviour were not translated into any difference in in vitro organic matter digestibility between Aries HD and Yatsyn 1. Keywords: Aries HD, digestibility, flowering, perennial ryegrass (Lolium perenne), tiller demography, tiller population density, tiller survival, Yatsyn 1
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(193 KB)The effects of soil properties on the availability of cobalt (Co) for pasture uptake have been studied using a wide range of New Zealand soils. There is a strong positive correlation between total or EDTA-extractable Co and manganese (Mn) concentration. However glasshouse studies have shown that Co availability is inversely related to the Mn concentration. Across a wide range of soil groups, EDTA-extractable Co is a poor predictor of cobalt availability. CaCl2-extractable Co was found to decrease with soil pH and was too pH sensitive to be a good predictor of Co availability. It is concluded that soil Mn plays a crucial role in soil Co status and has significant effects on plant Co uptake because of its involvement in the soil redox system and the scavenging properties of soil Mn oxides. Co deficiency is more likely to occur and Co fertiliser is less effective on soils with high Mn, especially under dry conditions. Keywords: lime, pasture cobalt, soil cobalt, soil manganese, soil moisture, trace elements
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(39 KB)Shelterbelts are a feature of the New Zealand landscape and in the dryland East Coast regions of the North Island, are seen in a diversity of planting patterns, species and silvicultural practices. To date, their economic benefits have not been assessed, partly because of the difficulty in evaluating the many interrelated pasture, soil, animal and forestry factors. Recent shelterbelt research in New Zealand has been conducted as a collaborative approach by AgResearch, Forest Research and Hort Research. Results of pasture, soil and tree measurements in the East Coast region indicate that shelterbelts, however managed, do not significantly increase pasture production in the sheltered zone. The competitive effects of trees reduce soil moisture in zones close to the shelter, which also encourages the accumulation of dung and urine nutrients in this zone by animals seeking protection. The modification in resting patterns as a result of shelter may be reflected in improved animal welfare and production but this was not measured. The value of timber from shelterbelts on the East Coast indicates that they have a role in diversifying farming income and offering a modified land use, which will help to sustain productive farming practices. Keywords: livestock, log value, pasture production, Pinus radiata, shelter, shelterbelts, soil moisture, soil nutrients, wood yields
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(186 KB)An East Coast hill country extension project has been running successfully for 5 years. A community group meets regularly to discuss farm development and farming policies, which may conclude with the manager adopting recommendations. The group includes people from agribusiness who freely give time and technical advice. Funding for extension activities only was available for the first 3 years. The project aims to improve farm production, while attending to environmental issues and to impart the knowledge gained to the wider community. An annual field day is held for the farming community. Significant gains have been made in production levels and soil conservation and other environmental work. It is also considered that the project has been effective in its extension role, although this is difficult to measure. Success of the project to date can be related to the continuing challenges that arise for the group and the property, which is typical of the wider Wairoa area, and the interesting group meetings and field days which draw good numbers of people. Assigning project members to task groups, designed to address specific issues, could give new impetus. Issues, which could be addressed, include the economic options for steeper country and the human factors of farming. The model is repeatable in other areas. Keywords: extension, forestry, hill country, soil conservation, sustainability
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(138 KB)Although the persistency of red clover (Trifolium pratense L.) can be a problem when grazed in mixed and pure stands, it is still regarded as a valuable source of high quality summer feed in some farming systems. Vegetatively reproductive red clover selections offer promise to solve this persistency problem but their growth, perennation, reproductive ability and productivity have not been investigated in New Zealand farming systems. This paper is an overview of a 4 year research programme involving nine experiments investigating these areas. The vegetatively reproductive red clovers evaluated were Astred, F2419 and Gualdo. There was no difference between Astred and Grasslands Pawera, a crown type red clover, in the total herbage accumulated over the first growing season under 4, 6 and 8 week grazing frequencies and lax and hard grazing intensities. After 3 years of grazing, significantly more Astred parent plants were alive compared to Pawera when rooted plantlets were counted as parent plants after one year. Varying numbers (0–66 plantlets/m2/yr) of rooted plantlets were produced by Astred in mixed and pure swards. More rooted plantlets were established per parent plant under wet surface soil conditions. Astred produced 57% of its autumn rooted plantlets on primary stems developed in September, or branches off these stems. Comparisons of the growth and morphology of Astred, F2419 and Gualdo are presented. Red clover selections that are vegetatively reproductive offer benefits to New Zealand farming systems and could solve some of the persistency problems currently experienced with red clover. Keywords: Astred, F2419, Gualdo, rooted plantlet, Trifolium pratense, vegetatively reproductive
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(176 KB)
OVERSEER™ is a nutrient budgeting model which estimates the inputs, outputs and balances of N, P, K and S for different farming systems. Its main role is as an index of the sustainability of farm systems and to provide information on the potential environmental impacts through estimates of nutrient leaching. OVERSEER was used to assess the N flows and balances associated with different management practices on the farm of Hawke’s Bay Dairies Ltd. The 210 ha farm includes a feed-pad for feeding cows with fruit and vegetable processing wastes and pasture which is cut and carried from a 41 ha effluent area (the latter is a requirement of the Regional Council consent). Outputs from OVERSEER for the effluent area revealed that N removal in cut pasture was 1.4 × total N inputs in effluent and clover N2 fixation and the total N balance was -117 kg N/ha/year. This could lead to significant pasture deterioration and would be unsustainable in its current state. Current N inputs for the whole farm system were estimated at 80, 147 and 87 kg N/ha/year in fertiliser, brought-in feed and clover N2 fixation. Outputs of N in milk and nitrate leaching were estimated at 154 and 66 kg N/ha/year, respectively. Hawke’s Bay Dairies propose changes in management to exclude the cut-and-carry operation. The effects of these changes on N flows and balances are presented and compared with those from the long-term farmlet trial at the Dairying Research Corporation Number 2 Dairy farm. In the Hawke’s Bay Dairies farm, high milk production (2200 kg milksolids/ ha) is being achieved through utilisation of locallyavailable fruit and vegetable wastes which are high in energy and low in protein. This results in very efficient conversion of total N inputs into milk (49%) and lower leaching losses than those measured in farmlet systems based on high (400 kg N/ ha/year) inputs of N fertiliser. Keywords: dairy farm, feed-pad, nitrate leaching, nitrogen model, OVERSEER™
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(184 KB)There is a wide range of farming enterprises in the Hawke’s Bay region because of the extended nature of the region, from Wairoa to south of Woodville, favourable climate and the mixture of soil types. This paper is therefore a general overview of the district and it attempts to provide some comparisons for those who attended the conference in 1975 and possibly 1955. Keywords: beef, cattle, climate, deer, forestry, goats, Hawke’s Bay, horticulture, sheep, soils, viticulture
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(143 KB)Over two million tonnes of fertiliser are applied to New Zealand pastures and crops annually and there is an increasing desire by farmers to ensure that the best possible economic return is gained from this investment. Spreading distribution measurements undertaken by Lincoln Ventures Ltd (LVL) have identified large variations in the evenness of fertiliser application by spreading machines which could lead to a failure to achieve optimum potential in some crop yields and to significant associated economic losses. To quantify these losses, a study was undertaken to calculate the effect of uneven fertiliser application on crop yield. From LVL’s spreader database, spread patterns from many machines were categorised by spread pattern type and by coefficient of variation (CV). These patterns were then used to calculate yield losses when they were combined with the response data from five representative cropping and pastoral situations. Nitrogen fertiliser on ryegrass seed crops shows significant production losses at a spread pattern CV between 30% and 40%. For P and S on pasture, the cumulative effect of uneven spreading accrues, until there is significant economic loss occurring by year 3 for both the Waikato dairy and Southland sheep and beef systems at CV values between 30% and 40%. For nitrogen on pasture, significant loss in a dairy system occurs at a CV of approximately 40% whereas for a sheep and beef system it is at a CV of 50%, where the financial return from nitrogen application has been calculated at the average gross revenue of the farming system. The conclusion of this study is that the current Spreadmark standards are a satisfactory basis for defining the evenness requirements of fertiliser applications in most circumstances. On the basis of Spreadmark testing to date, more than 50% of the national commercial spreading fleet fails to meet the standard for nitrogenous fertilisers and 40% fails to meet the standard for phosphatic fertilisers.Keywords: aerial spreading, crop response, economic loss, fertiliser, ground spreading, striping, uneven application, uneven spreading, yield loss
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(184 KB)The fertiliser requirements of hill country vary with soil type, slope and aspect-related factors which govern pasture production potential and species composition. In most situations, the topographic complexity is such that only very broad differentiation in land units can be made when aerially applying fertiliser. The traditional method of aerial topdressing is for superphosphate to be flown on at a common rate over large blocks of complex topography by fixed-wing aircraft. Advances in geographical positioning system (GPS) and aircraft technology now allow aircraft to fly accurately defined track spacing and so achieve optimum uniformity of fertiliser spread. The same technology could be used to vary fertiliser application rate along a flight path according to predetermined recommendations and through links to a farm geographic information system (GIS) map. This approach could also be used to apply different fertiliser types. In a desktop study the effects of differential, compared with uniform, fertiliser application policies, on animal productivity and economic returns were examined for three contrasting hill farm situations using a combination of trial results and the AgResearch PKS Lime Programme. Results showed that for a farm with a low soil P status (Olsen P =9), that stocking rate could be increased by 0.5 su/ha, and the economic return by 7.5%, by differential, rather than uniform fertiliser application. In a similar but higher soil P status farm (Olsen P = 15), the increase was 0.9 su/ ha and 10.1% respectively. In a summer-dry situation where nitrogen fertiliser could be substituted for some P fertiliser, a differential policy designed to optimise production gave a 2.1 su/ha and 43% net margin increase, compared with the uniform application of a typical rate of maintenance P fertiliser only. The results from the desktop study are discussed in relation to the practical aspects of developing differential fertiliser application methods. This will relate to extra fertiliser application cost, and the definition of practical sized land units and fertiliser forms, which will all have some effect on the net economics of a differential application policy. Despite these unknowns, the technology would appear to offer real gains to the hill country farmer. Keywords: economic return, fertiliser application, GIS, GPS, hill country, phosphate
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(158 KB)Precision farming has captured the imagination of many in terms of what it can offer. It is based on simple ideas that appear to make perfect sense. Firstly: feed a crop only to its potential in that particular location. Secondly: spray and treat only those areas that require treatment for control of disease and weed problems. This technique offers improved profits through increased yield as well as potential savings in input costs. There are however additional costs that must be met. These include a global positioning system (GPS), additional controllers and monitoring devices on machinery, data storage devices on vehicles and additional software to manage and analyse the data produced. Much of the work completed around the world has been directed towards combinable crops, there are however increasing numbers of yield mapping systems being developed for other machines such as forage harvesters, grape harvesters and root harvesters. Indeed higher value crops would appear to offer greater potential for increased profit. This paper examines the technology adoption process and discusses some of the issues likely to affect adoption of precision farming here in New Zealand. Keywords: DGPS, GIS, mechanisation systems, precision farming, variable rate applications
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(190 KB)
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