Much has been written and spoken over the years about continually declining inflation adjusted commodity prices, the volatility of the New Zealand dollar, and the difficulties of competing against subsidized agricultural sectors. While NZ agriculture has enjoyed good levels of profitability in recent years these underlying forces still remain and will continue to impact farm profitability. Rising land prices and improved productivity of our competitors are likely to erode NZ agriculture’s tr aditional position as a low cost producer in the future. The commonly cited responses to the forces outlined above are 1) adding value to commodities, and 2) increasing productivity. An earlier analysis showed that the NZ sheep and beef sector, in particular, was experiencing decreasing prices in real terms and farm productivity had remained largely unchanged for fifty years. In contrast to the data reviewed earlier, this paper shows that over the last fifteen years the NZ agricultural industry has been exhibiting just those responses required to combat the forces above. New Zealand lamb prices have increased in real terms since the late-1980s and in comparison with international prices. Beef and dairy prices have also fallen substantially less than the comparative international price, however wool and wheat prices have fallen more than the international price. In addition, there have been significant increases in farm pr oductivity, most notably lambing percentage, lamb carcass weights, and milksolids production/ cow. The result has been a 57% increase in dairy Earnings Before Inter est and Tax (EBIT) over the past 5 years, compared with the previous half decade (measured in real terms). Sheep farming has experienced a 79% increase in EBIT over the same period. The challenge and subject of significant debate which is outside the scope of this paper is how NZ agriculture is to remain at the forefront of global pastoral agriculture as a low cost, innovative, and profitable sector. Keywords: agricultural productivity, farm profitability, product prices, New Zealand agriculture.
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(108 KB)A proud history As we look forward and plan for the future of the New Zealand Grassland Association (NZGA) you have to be able to reflect on the foundation on which this Association has been built. As we enter our 75th year of existence we can reflect on a very proud history well documented in 1989 by Derek Woodfield and Deric Charlton.
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The rapid spread of clover root weevil (Sitona lepidus) (CRW) since its introduction in the early 1990s, threatens the competitive advantage of New Zealand’s pastoral industry. When CRW was discovered, it had already spr ead too far for containment. The insect’s distribution currently covers the North Island and there is no reason to prevent its spread ultimately throughout NZ. With no competing species, CRW is more damaging in NZ than in its native Europe. Clover root weevil affects white clover nitrogen (N) fixation while simultaneously reducing the clover content of pastures thereby lowering total forage quality. Legume germplasm was screened for resistance/tolerance and while no resistance was discovered, vigorous growing white c lover plants showed tolerance to CRW and gains from selection for tolerance were achieved. Eliminating remnant clover before pasture renovation or growing a crop between grass stages reduces the resident CRW population and improves clover re-establishment. However, CRW can reinvade and potentially return to its original density. Two candidate biological control agents are being pursued for release later in 2005. Clover root weevil’s impact on pastoral farming varies, partially due to environmental variation, which dictates clover growth and CRW development. Keywords: clover root weevil, cultivar selection, life cycle analysis, pasture management, Sitona lepidus
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(82 KB)Clover root weevil (CRW) has become a major pest of white clover in pastures in much of the North Island. In contemporary, intensively stocked pastures, high volumes of nitrogen (N) cycling through the soil/plant/ animal system stimulate grass growth and reduce the clover content of pastures. Clover root weevil imposes further stresses on clovers. A range of white and red clover germplasm was evaluated f or CRW tolerance from 2002-2005 on Waikato dairy and sheep/beef farms. Results confirmed the importance of good agronomic adaptation if clovers are to survive the additional stress of CRW. Two recently released white clover cultivars (Grasslands Kopu II and Tribute) were amongst the top performing lines under dairy farm grazing. Under sheep/ beef grazing, spreading type red clovers also performed well. A white c lover breeding line selected for tolerance of plant-feeding nematodes was in the top group of clovers at both sites. Reducing stresses on clovers from other pasture pests will contribute to improved tolerance to CRW. A glasshouse experiment showed that CRW larval feeding can severely damage white clover nodules and reduce N fixation. The plants have considerable capacity to grow new nodules but this diverts energy away from other growth processes. Our conclusions are that welladapted, vigorous white clover cultivars are better able to cope with the additional stress imposed by the root weevil. Good pasture management and attention to fertiliser requirements can improve clover survival under root weevil herbivory. New generation red clovers show considerable potential for weevil infested areas. Coselection for tolerance/resistance to other major clover pests e.g. clover flea and root nematodes will improve plant performance under CRW stress. Keywords: clover root weevil, nitrogen fixation, plant breeding, red clover, white clover
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(68 KB)Breeding for improved resistance and tolerance to the clover root-knot nematode, Meloidogyne trifoliophila, and the clover cyst nematode, Heterodera trifolii , has been successful in white c lover, Trifolium repens. White clover lines developed from three independent breeding programmes were established in field trials at Lincoln, Palmerston North, Cambridge and Kerikeri. Plants were established in areas either untreated or treated with nematicide, so as to have contrasting pest loads on the plant material and evaluated for up to 4 years. Plant vigour was scored before each grazing at each site. Clover cyst nematode cysts were counted twice in Palmerston North and all nematodes were counted in stained roots on four occasions in Cambridge. Resistant lines from the clover cyst nematode programme performed better than susceptible lines and as well as most cultivars reflecting the high level of resistance developed in this glasshouse-based programme. This resistance was also reflected in the generally lower number of cysts counted under resistant lines from Palmerston North. The root-knot nematode resistant material performed better than the susceptible and as well as most cultivars. The tolerance selections, developed under field conditions, performed as well as, or better than the cultivars. The selections from the breeding programmes have exhibited strong agronomic potential across locations and years and the best material has been crossed, with progeny being assessed in current field trials. Keywords: Heterodera trifolii, Meloidogyne trifoliophila, nematode, pasture, resistance, tolerance, white clover
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(63 KB)The establishment of new clover-based pastures takes a full year and has two distinct components; seedling emergence from sowing, and subsequent grazing management. A Ministry of Agriculture and Forestry (MAF) Sustainable Farming Fund (SFF) project to investigate the causes of inconsistency of white clover establishment concluded this came primarily from a lack of knowledge of white clover in both sowing and grazing management skills, and reflected how far modern farming technology has moved away from clover-based systems towards nitrogen (N)-boosted systems in recent years. Typically, less than half the seed being sown emerges, for both ryegrass and clover, although good results do occur. A trial looking into seedbed conditions on a dairy farm highlighted the importance of good seedbed consolidation in order to accurately control sowing depth, lifting white clover emergence by 50% and ryegrass by 25% using a roller drill. Consolidation did not affect emergence using a triple disc drill, but it did improve quality of sowing by reducing soil drag and spill by the rear coulters causing excessive burial of the front coulters rows. Differences in emergence were still evident in the performance of the clover in the following summer with 14% clover in the areas that had been hard rolled compared to 4% where it had not. In another trial on a hill soil of lower N fertility status, the taking of hay crops in the first summer, not a normally recommended practise, enhanced clover establishment compared to rotational grazing all year. The roles of clover, N fixation and quality feed, are discussed in the context of how and where clover may fit into modern farm systems. Keywords: emergence, establishment, grazing management, seedbed preparation, sowing methods, white clover
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Dairy Systems Monitoring (DSM) was developed out of response from dairy farmers for a benchmarking tool that made fair and equitable comparisons between farms. This benchmarking system is used by the clients to improve their productivity and profitability. The dairy farm simulation model UDDER is used to simulate the farm system. The input information is milk production from fencepost, and monthly data from the farm, including, areas, stock numbers, supplements, crops and nitrogen (N). The model is then calibrated to simulate the farms production, revised and validated monthly. There has been a successful uptake of this program. Currently 50 farms are involved. Dairy Systems Monitoring has generated change in the systems of participating farmers. Dairy Systems Monitoring has proven to be an effective tool to demonstrate the impact of a range of new technologies on farm systems. The tool is used on an ongoing basis to simulate and compare different operating strategies. It has the ability for clients to compare themselves to simular farms. A key benchmark that is analysed is the feed harvested. For every additional 1 tonne of dry matter (DM) harvested, the gross margin (GM) increases by $339/ha. The question this poses for participants is “how do we harvest more pasture”? Is it by growing more pasture, or improving management to harvest more of the existing pasture growth? Dairy Systems Monitoring is an effective extension tool to highlight the impact of new technologies or management practices on the client’s farm program. Keywords: benchmarking, dairy farm programmes, feed harvested, gross margins, UDDER model
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(90 KB)Over four dairy seasons (2000/2001 to 2003/2004) the input of maize silage was evaluated at the Waimate West Demonstration Farm. Two systems were evaluated with Jersey cows: Control (3.8 cows/ha, no maize silage) and High stocked (HS) Maize (5 cows/ha, up to 1.5 t dry matter (DM)/cow/yr as maize silage). Both farmlets received 190 (±5) kg nitrogen (N)/ha/yr in split applications throughout the season, and calving commenced on 9 July for both herds. Only small differences between treatments in annual milksolids (MS) yield/cow were recorded. The Control herd averaged 310 kg MS/cow in 260 days compared with 316 kg MS/cow in 277 days for the HS Maize herd. The HS Maize herd produced 34% more MS/ha than the Control herd, viz. 1566 and 1172 kg/ha/yr respectively. Milksolids response to the additional DM and higher stocking rate (SR) on the HS Maize system averaged 80 g MS/kg extra DM consumed. The annual economic farm surplus (EFS) averaged over 4 years for the Control herd was $2784/ha and the HS Maize herd was $2551/ha, however greater between year variation in EFS was noted for the HS Maize system. Incorporation of maize silage into a pasture-based dairy system does increase production/ha, however the profitability of the system will be more vulnerable to MS payout and maize silage price than the traditional pasture-based system. Keywords: dairy, economic farm surplus, maize silage, pasture production
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(69 KB)The aim of the Resource Efficient Dairying (RED) trial is to measure the productivity, economic and environmental effects of different feed inputs and management processes on a dairy farm. This is a longterm systems trial located at Scott Farm (Dexcel Research Farm) established on 1st June 2001 and expected to continue until 2006. Trial design was based on six systems that have an allowance of up to 200 kg nitrogen (N)/ha (excluding the low input treatment). They are: low input (no N fertiliser, heifers grazed-on and 2.3 cows/ha); control (3 cows/ha); standoff (3 cows/ha); low supplement input (5 t dry matter (DM) maize silage/ha, 3.8 cows/ha); moderate supplement input (10 t DM maize silage/ha; 5.2 cows/ha); and high supplement input (15 t DM maize silage + 5 t soymeal/ha; 6.9 cows/ha). The last two systems have irrigation available to boost pasture production. All systems were designed to operate at a common comparative stocking rate (CSR) of 85 kg liveweight (LW)/t DM. Two seasons’ data have shown that increasing the stocking rate (SR) by 1.5 cows/ha from 3.8 to 5.3 cows/ha, plus extra feed, increased output by 90 and 184 kg milksolids (MS)/total ha in the two years, when the extra area required to supply the extra feed is included in the calculation of kg MS/ha. However the further increase to 6.9 cows/ha plus extra feed produced less MS/total ha than the system stocked at 3.8 cows/ha. Calculations of economic farm surplus (EFS) and return on assets (ROA) reveal that when the payout is $3.50/kg MS the low input system is competitive irrespective of land price ($18000 or $37000/ha) or supplement cost (18 c or 24 c/kg DM). Conversely at a higher payout of $4.50/kg MS the treatment supplemented with 10 t maize silage DM/ha is competitive over the range of land prices and supplement costs tested. Keywords: dairy cows, economic evaluation, maize silage, milksolids, nitrogen fertiliser, stocking rate
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(81 KB)A four-herd dairy farm farmlet trial was carried out on the Stratford Demonstration Farm in Central Taranaki for four seasons (2001/2002 to 2004/2005). This trial examined the profitability and practicality of different feed input systems including on-farm forage cropping and the use of new pastures. The farmlets included: 1. A self-contained control group moderately stocked at 3.3 Jersey cows/ha. 2. A group with the same stocking rate (SR) but using high quality silage made on the farmlet to allow milking for a long lactation (280 days/cow) and feed purchased to balance the winter feed budget (MPF). 3. A group, high stocked at 4 Jersey cows/ha to allow direct grazing of the grass by milking cows with minimal supplements made but feed purchased (grass silage and hay, maize silage, winter grazingoff) to allow a moderate to long lactation length (270 days/cow) and to balance the winter feed budget (HPF). 4. A group also at the moderate SR and self-contained but with 12% of the farmlet cropped with summer turnips and Triticale cereal silage crops to increase total feed production, as well as introduce the use of higher quality pasture cultivars (crop). Increased milk production was achieved by the increased inputs with a response rate of 142 g milksolids (MS)/kg dry matter (DM) from buying-in feed to extend the lactation and 84 g MS/kg DM from buying-in feed to run a higher SR. The cropping and regrassing system also resulted in a 4.9% increase in MS production, but crop yields were much lower than expected, significantly affecting the results. The MPF group with purchased feed to extend the lactation produced the best economic result under the costs and milk payouts used. The HPF group produced the most variable and lowest economic result. The extra milk production from this group was sufficient to cover the extra feed costs but not the cost of running the extra cows. The extra milk production on the cropping farmlet covered the cost of the cropping and allowed a high level of regrassing at no net cost, but minimal economic benefit. The value of the new pastures in the system, however, improved each season. Labour costs, feed costs and milk payout are critical factors in the differing economic results. These vary greatly from farm-to-farm, and year-to-year and differences here can change the relative economics of each system. Keywords: economic farm surplus, feed input systems, milksolids production, profit
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A model of the New Zealand beef value chain, from conception to export, was constructed. The model was parameterised at the national level so that issues and opportunities within the beef industry can be examined at a high level by researchers and industry participants. The model is capable of modelling changes in farm practice, market situations and the industry structure. To illustrate the integrative power and value of the model in evaluating change within the beef sector, three scenarios are presented and compared to the status quo: changes in land price; wider use of beef semen in the dairy industry; and introduction of a gene to improve net feed intake. From the three scenarios presented, it is apparent that land price dominates the ability of the NZ beef industry to create value in the long-run. Although behaviour, practices and technologies can contribute to overcoming this factor, such changes will need to be substantive – incremental improvements will not be sufficient. This model provides the basis for facilitating debate on the future of NZ’s beef industry and how to ensure long-run profitability. Keywords: beef industry, scenario evaluation, beef systems, value chain model
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(79 KB)Potassium chloride (KCl) was applied at 4 rates (0, 150, 450 and 1150 kg/ha) to pasture on closed 5 ha farmlets over 3 years, and pasture and animal production and animal health measured. Friesan, Jersey and Friesan x Jersey cows were stocked at 3.2/ha on an Egmont Allophanic soil near Hawera in South Taranaki. Average soil potassium quick test (QTK) levels were 7, 8, 10 and 12 respectively from 0, 150, 450 and 1150 kg KCl/ha. There was a small significant negative linear effect of rate of KCl application on annual pasture dry matter (DM) production averaged over three years (16864 – 18359 kg/ha). The average amount of silage conserved (1369 – 2112 kg DM/ha) was consistently greater at the highest rate of KCl. Increasing rate of KCl had no significant effect on the nutritive value of grazed pasture but resulted in increased K content of silage. There was no significant effect of KCl on milksolids (MS) production (1034 –1179 kg/ha/lactation) or reproductive performance. There was a trend for the incidence of clinical metabolic disorders (8-18%) to decrease with increasing rate of KCl but this was not significant because of the low number of cows in each herd. The results from this trial suggest that soil QTK levels above the target range for optimal pasture production of 7-10 on Allophanic soils are not associated with increased dairy production and have no adverse effect on animal health. Keywords: calcium, dairy cows, hypocalcaemia, hypomagnesaemia, magnesium, milksolids, pasture, potassium, potassium chloride
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(59 KB)A telephone survey of dairy farmers, calf rearing farmers, and finishing farmers was undertaken to discover opinions regarding dairy-beef cattle and the barriers to increasing the quality and quantity of dairy-beef cattle produced by the dairy industry. A total of 158 farmers were surveyed from throughout New Zealand. Dairy farmers make the most critical decisions regarding the genetic make-up of most cattle entering the NZ beef industry. To ensur e these decisions benefit the beef industry, there is a need for incentives to encourage dairy farmers to use more beef genetics across their herds. The survey results suggest a premium for dairy-beef calves of $30-$50/calf above Friesian bull calf prices would be an adequate incentive. Delivering this premium requires a co-ordinated effort involving beef finishers, calf rearers, dairy farmers and beef processors. Keywords: beef finishers, calf rearers, dairy-beef cattle, dairy farmers, incentives, industry co-ordination
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(94 KB)Although summer is a critical season for sheep production on summer-wet hill country, little is known about how high-performing farmers manage livestock and pastures during this period. If their practices could be captured and disseminated, it would provide the opportunity for other farmer s to increase productivity. The decisions made by a high-performing summer-wet hill-country farmer over summer were investigated using a single-case study design. This study highlights the relative complexity of summer management on hill country. Farmers must consider key strategic decisions such as when to wean, when to sell, what to sell, how many to sell, where to sell and at what weight. In this study, the answer s to these questions were found to be a function of the conditions (summerwet versus summer-dry) under which one farms and the amount of finishing country one has. Under summerwet conditions, the need to control pasture quality dictates important strategic decisions. To control pasture quality, the case farmer runs a high stocking rate (SR), high performance, later lambing system with a low sheep:cattle ratio. This system, particularly with a low proportion of finishing country, is not conducive to lamb finishing and a store policy is a more profitable alternative. As such, the case farmer’s focus over summer is on ensuring the potential for high ovulation and conception rates in his ewes and ewe hoggets rather than lamb finishing. This is achieved by ensuring his ewes are in good condition (2.7 condition score (CS)) with adequate feed (1400 kg dry matter (DM)/ha) at flushing and his ewe hoggets reach 41 kg live weight (LW) by May 1st. These nonnegotiable targets are central to the farmer’s consistent high performance. Minimisation of the distribution of LW (or CS) a bout the mean of different sheep classes through preferential feeding of younger, lighter and thinner stock was also found to be a critical element. To achieve high lamb growth rates, low priority stock and older finishing cattle were used to ensure pastures remained actively growing, of high quality and with low levels of infective larvae. A late weaning date and a high proportion of cattle and older stock were also important in maintaining pasture quality on summer-wet hill country. A critical feature of summer grazing management is area allocation and the use of post-grazing residuals to achieve animal performance targets. Pasture monitoring, microbudgeting and the use of this information in conjunction with market related data, to help decide the appropriate timing of stock sales was central to coping with uncertainty and achieving pasture and animal targets. Keywords: farmer decision making, grazing management, sheep productivity
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The approach was to use the Whole Farm Model (WFM) and Taranaki climate to compare a conventional, twice-a-day milking farm system with variations of once-a-day (OAD) milking and high-input systems. The aim was to compare production, return on assets (ROA) and risk as affected by climate and price variability. Simulations were run over 9 different climate years (1995/1996 – 2003/2004). The high-input system had the highest production (1333 kg milksolids (MS)/ ha) and highest ROA (10.8%), with variability thereof dampened by a feed buffer of higher quantity and quality that existed because of higher pasture yields (15.8 t dry matter (DM)/ha with 200 kg nitrogen (N)/ha vs. 13.5 t DM/ha with 105 kg N/ha for the other two systems), maize silage and grazing-off. The high-input system was followed by the OAD and conventional systems in terms of production (1068 and 975 kg MS/ha respectively) and ROA (9.8% and 9.2% respectively). Both OAD and conventional systems showed risk values nominally lower than high-input, but both these systems were more severely affected by climatic var iability, which lowered the average return and increased the risk relative to the return. Keywords: climate var iability, high input farming, once-a-day milking, return on assets
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(62 KB)The intensification of dairying can have adverse impacts on the environment through diminished soil quality and greater loss of nutrients to water bodies. Poor soil quality can reduce the productivity and sustainability of pastoral farming systems. The effects of increased stocking rate (SR) (3, 4 and 5 cows/ha) and introducing a cut and carry system on soil, pasture and water quality were compared with a pasture fallow on an Egmont Allophanic soil in South Taranaki over three years. Soil nutrient and organic matter (OM) levels were not affected by the treatments imposed and were maintained in the ranges for adequate plant growth by the application of fertiliser (grazing) or farm dairy effluent (cut and carry). Macroporosity in the top 5 cm of soil was greater for the fallow treatment (31-37%) than the other treatments (cut and carry 20-25%; grazing 17-21%). Treading damage as indicated by soil surface roughness only increased with SR in one winter grazing when the soil was saturated. The management treatments had no significant effect on annual pasture production. Ryegrass content significantly increased with grazing and higher SRs and there was more dead material in the fallow treatment. Pasture chloride (Cl), potassium (K), nitrogen (N) and phosphorus (P) contents were significantly lower in the fallow treatment and pasture K content significantly lower in the cut and carry treatment than in the grazing treatments. The leaching loss of calcium (Ca) was significantly lower in the fallow treatment in 2003, and in 2004, the rate of magnesium (Mg) leaching increased in the grazing treatments. Nitrate-N leaching losses were low (average 5 kg/ha/yr) but in the 2004 drainage season were significantly higher in the fallow compared with the cut and carry and grazing treatments. Overall it could be concluded that the more intensive management had no adverse effect in the short term on the sustainability and quality of soil, pasture and groundwater. Keywords: dairying, nutrient leaching, nutrients, pasture, soil macroporosity, sustainability
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(156 KB)On the night of February 14th 2004 the lower North Island was hit with a storm system, which would cause the biggest flood seen in the region for over 100 years. The hardest hit areas include the Manawatu, Rangitikei, Horowhenua, Wairarapa and Wanganui regions. In the summer after the event, a survey was conducted of the affected areas. Semi-structured interviews of 52 individual farmers focused on their farm operations, the impact of the flood, and their regrassing strategies. The interviews established the state of the pastures postflood including depth and texture of silt deposit; water levels and flow; duration of inundation; and soil surface condition. The regrassing strategies included seedbed preparation, sowing technique, fertilizer use and weed control. Site measurements made were: pasture cover and species content, and that soil profiles revealed rooting depth and silt depth (if not cultivated). General trends that emerged were that the more thoroughly a seedbed was prepared the lower the risk of pasture establishment failure. Nitrogen (N) applications of 75 kg/ha over the intervening period did not have a significant effect but where deep sediment was encountered two or three applications of N was reported to produce feed and start inputting organic matter (OM). The use of a roller drill increased the reliability of establishment and was essential for the establishment of pasture legumes. Double normal seeding rates (30-40 kg/ha) increased the reliability of success where the seed was broadcast. Many farmers that had no sediment reported perennial weed problems including couch, creeping buttercup and a variety of thistles. Small scale surface cultivation was reported to decrease drying time dramatically in extremely wet areas. Keywords: ground cover, pasture cultivars, pasture establishment, seedbed preparation, weeds and pests
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(140 KB)New Zealand has had many changes in the dairy industry during the last twenty years. As NZ dairy farming has particular characteristics (e.g. differing ownership structures, geographic areas) risk perception and management strategies may differ significantly between them. No studies have been undertaken regarding the differences in perception of risk and risk management strategies used by different gr oups of dairy farmer s. A survey of 1000 NZ dairy farmers was conducted in 2004 and further analysed to address this need. In the survey the dairy farmers were asked to assess their perception of risk sources and the importance they attached to risk management strategies. Using a 1 to 5 scale, mean scores of both risk sources and management strategies were compared (Z-test) by ownership structure and geographic location. The differences in the perception of risk between sharemilkers and owner-operators were mainly in the sources categorised as “market” and “human”. “Changes in land prices” was highly important for sharemilkers. Differences of risk management strategies were noted in the “financial” and “production” categories. The main sources of risk perceived differently by farmers in the North and South Islands were in the production side of the business. Although farmer s from both islands were similarly focused on controlling risk through production management strategies, those from the South Island were keener to use financial responses. In conclusion, sharemilkers were more concerned with the changes of prices of both inputs and outputs than owner-operators. Sharemilkers were more production-orientated to manage risk than farm owners, and they also were more focused on off-farm income and debt management. Differences in both the risk perception and the risk management strategies used in each island are related to differences in farm sizes and the developmental stage of the dairy sector in each island. Keywords: risk perception, risk management strategies, sharemilkers
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The utilisation of whole-crop cereal silage, when fed on pasture, is an unknown factor when assessing the economics of whole-crop cereal silage in dairy farming systems. This study aimed to document the utilisation of whole-crop cereal silage and compare it to the utilisation of pasture silage fed under the same conditions. Data was collected from nine whole-crop cereal and two pasture silage feeding events during the autumn and spring of 2004. The concentration of silage fed in spring (3.04 kg (dry matter) DM/m) was lower (P<0.001) than that fed in autumn (4.59 kg DM/m). Residual silage left after feeding (kg/m fed) was not significantly affected by season or silage type. When expressed as a percentage of that fed, utilisation was lower for whole-crop cereal silage (80.6%) than for pasture silage (90.4%; P<0.032). However, when silage utilisation (g/kg DM fed) and the amount fed (kg DM) were compared, the utilisation of the silage was positively related to the amount fed (r2 = 0.44; P<0.001) with utilisation of over 90% being achieved when more than 4 kg DM/m was fed (measured in 38% of the feeding events). Keywords: dairy cows, pasture, silage, utilisation, whole-crop cereal
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(51 KB)Improved productivity and utilisation of forages will be central to maintaining business viability on high value Tar anaki dairy land. Data from 712 plots in 119 trials planted over ten years in Taranaki was analysed to determine average yields and the impact of planting date on yield. Six rural contractors who plant approx. 90% of maize in Taranaki were surveyed to determine the perceived factors most limiting maize yields in the Taranaki. The overall average Taranaki maize silage dry matter (DM) yield of all hybrids from the trialling program over the past ten years was 20.5 t DM/ha and the average harvest DM content was 33.8 %. Currently commercially available hybrids yielded an average of 20 t DM/ha. Average maize silage yield/yr varied from a high of 22 t DM/ha in 1999 to a low of 18.3 t DM/ha in 2004. Planting between the 15th and 24th October gave the greatest crop yield. Paddock selection seemed to be driven by the need for pasture renovation rather than paddocks being selected because they provide an ideal growing environment for maize. Contractors suggested shelter was a key consideration for increasing yields. Keywords: cropping , maize silage , Taranaki
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(61 KB)Three experiments were conducted to compare milksolids (MS) production from cows grazing similar herbage allowances of timothy (Phleum pratense)/white clover (Trifolium repens) and perennial ryegrass (Lolium spp.) pastures. Two experiments were shortterm (2 weeks), one in spring 2000 (Experiment 1) and one in autumn 2001 (Experiment 2), and one longerterm (12 weeks) irrigated trial in summer/autumn 2002 (Experiment 3). In Experiment 1, the yield of all milk components; fat, protein, MS, casein and lactose, was greater from timothy/white clover than ryegrass, whereas in Experiment 2, the production of these components from timothy/white clover was less than from ryegrass. The protein content of timothy/white clover was greater than ryegrass in spring (P<0.05) but similar in autumn. In spring, acid detergent fibre (ADF) and neutral detergent fibre (NDF) were similar but in autumn they tended to be higher in timothy/white clover than ryegrass, indicating poorer quality of timothy/white clover relative to ryegrass in autumn. In spring and autumn the digestibility and metabolisable energy (ME) of the two pastures types were similar. In Exper iment 3 the pastures were irrigated. The experiment was a crossover design with the cows grazing each of the timothy/white clover and ryegrass pastures for two, three-week periods. The yield of all milk components was greater from Timothy/white clover than ryegrass. Digestibility and ME were similar for the two pastures but the timothy/white clover pastures had lower NDF and higher water-soluble sugar content than ryegrass. More cows were carried on the timothy/white clover pasture and as a result MS production/ha was increased by 30%. This research identifies an opportunity for greater use of irrigated timothy/white clover pasture in dairying systems not subjected to an Argentine Stem Weevil (ASW) challenge. Keywords: milksolids production, nutrient composition, perennial ryegrass, timothy, white clover
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This study compared the yield and nutritive content of conventional and leafy maize silage hybrids, and the expected differences in milksolids (MS) production if fed to cows. A range of conventional and leafy hybrids were planted in paired strip trials (n=162) or small plot trials (n=132) during spring 1999, 2000, 2001, 2002, 2003, and 2004 in all of the main maize silage growing areas from Nor thland to Canterbury. Pair ed comparisons of short, medium, and long maturity conventional and leafy hybrids were made. On average, conventional hybrids yielded 1824 kg DM/ha (9%) more than leafy hybrids and had a marginally lower fibre digestibility (0.6 percentage units). Modelling using the Cornell Net Carbohydrate and Protein Systems (CNCPS) model showed that leafy hybrids had a similar metabolisable energy (ME) content and MS per cow and per tonne of maize silage were not different. For dairy farmers growing their own maize silage crop to feed to cows, the planting of conventional hybrids will result in more MS and profit/ ha of maize grown than will the planting of leafy hybrids. If maize silage is purchased on a cent/kg dry matter (DM) basis, the small differences in nutritive content of leafy and conventional hybrids will not affect MS production or profit. Keywords: dairy cows, leafy hybrids, maize silage yield, nutritive value
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(62 KB)A series of in vitro incubations with kikuyu grass (Pennisetum clandestinum), lucerne and six legumes containing condensed tannins (CT) were undertaken to evaluate this technique against in vivo trials in New Zealand, measuring methane emissions. Published trials have demonstrated a reduction in methane emissions associated with CT and in one instance from kikuyu. The incubations used fresh minced forage (equivalent to 0.5 g dry matter (DM)) and were carried out in 50 ml sealed bottles containing buffer and rumen inoculum. Gas was sampled through a septum to monitor volume and composition throughout the 24h incubation. Incubation for 24 h resulted in 2.4–6.6 % conversion of DM to methane, and suggested CT concentrations below about 8% of the DM can reduce methane production without inhibiting fermentation rate. Higher concentrations of CT (> 8%) were associated with a lower rate of digestion. In common with in vivo trials, CT concentration in forage DM was inversely related to methane (adjusted R2 = 0.49; P = 0.01) and volatile fatty acid (adjusted R2=0.86; P<0.001) production. Ash concentration in forage DM was proportionally related to methane (adjusted R2=0.56; P=0.005). Keywords: ash, condensed tannins, in vitro incubation, methane, rumen
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(107 KB)Grazing management is concerned with managing the interactions between plants and animals. Two management factors that require consideration are the optimal grazing time and the effect of grazing severity on subsequent regrowth. The objective of the current study was to quantify the effect of grazing severity in winter on leaf appearance r ate , herbage accumulation and quality, and plant energy r eserves. Ten pasture areas were grazed to two different residual masses (1260 ± 101 and 1868 ± 139 kg dry matter (DM)/ha, Severe and Lax, respectively) over five consecutive days by dry dairy cows. Neither growth rate (average 15 kg DM/ha/day), nor leaf appearance rate (average 16 days/new leaf) differed between treatments. As a result, herbage accumulated over the 49-day regrowth period was similar between grazing treatments (736 and 715 kg DM/ha for Severe and Lax, respectively), although herbage mass when three new leaves had emerged on regrowing tillers (third leaf stage) was greater on the laxly grazed treatment. Perennial ryegrass plants defoliated more severely displayed a trend for lower levels of water-soluble carbohydrates (WSC) than plants defoliated more laxly, but this difference had disappeared by the third leaf stage of regrowth. Pasture quality was improved in the severely defoliated treatment, with higher digestibility, WSC and metabolisable energy (ME) concentrations, and (ADF) lower acid and neutral detergent fibre (NDF) concentrations. Keywords: grazing sever ity, herbage production, water-soluble carbohydrates
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(80 KB)In a choice trial in a glasshouse, infection of tall fescue with the endophyte AR542 significantly reduced feeding by adult Argentine stem weevil (ASW) in the cultivar J esup but not in Advance in comparison with the same cultivars without endophyte. Paddocks of Quantum infected with AR542 that were sampled on two Northland farms consistently had fewer tillers damaged by Argentine stem weevil than equivalent paddocks of endophyte-free (Nil) tall fescue. In comparison to Nil plants, AR542 in Jesup and Advance had significantly fewer plants and tillers damaged by adult black beetle in a glasshouse choice trial. Fewer tillers were also damaged by adult black beetle in Advance tall fescue infected with AR501 and AR502 than in Nil Advance in a small plot field trial at Kerikeri. In a similar trial at Ruakura, the occurrence of adult black beetle and signs of larval damage were high in endophyte-free plots and considerably reduced in endophyte-infected plots. It is concluded that the nontoxic endophytes will lessen damage by black beetle and ASW in a range of tall fescue cultivars and that this is likely to contribute to increases in productivity and persistence of this forage grass. Keywords: Argentine stem weevil, black beetle, AR542 endophyte, Neotyphodium, tall fescue
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(66 KB)The effect of fine slurried lime applied at 200 kg/ha on soil pH at two depths was compared with 400 and 2500 kg/ha of local agricultural (ag) lime in the presence and absence of sulphur (S) superphosphate 20, in Marlborough hill country for one year. In the absence of fertiliser all lime treatments significantly raised soil pH in the top 25 mm for the 355 days after application. Initial responses declined from day 14 or 35 to day 138 before increasing at day 355. Fine lime did not significantly alter pH in the 25-75 mm zone until day 355. The low rate of ag lime significantly raised pH in the 25-75 mm zone for the whole year. The high rate of ag lime significantly increased pH in the top 25 mm over the other lime treatments for the 355 days and over the fine lime treatment in the 25-75 mm zone from day 35. In the presence of fertiliser in the top 25 mm, fine lime significantly increased pH at day 14 only, and low ag lime at day 355 only. The high rate of ag lime significantly increased pH over the control from day 14 and over the other lime rates from day 35. In the 25-75 mm zone the high rate of ag lime significantly increased pH over the control and the low ag lime rate from day 71 but was significantly better than fine lime from day 35. It is likely that rain immediately after application and higher than average annual rainfall hastened the release of fine and intermediate particles of lime. However provided lime meets the accepted criteria for particle size distribution and maximum size it is the rate of application which dictates the magnitude of response. In Marlborough hill country it was 43% cheaper to aerially apply 400 kg/ha of ag lime compared to 200 kg/ha of fine lime with the added benefit of a greater residual effect beyond one year. Keywords: agricultural lime, fine lime, slurry, soil pH
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