AIMS: To examine attitudes, priorities, and constraints pertaining to herd reproductive management perceived by farmers managing seasonal-calving, pasture-based dairy herds in four regions of New Zealand, and to explore how these varied with demographic and biophysical factors. METHODS:Key decision makers (KDM) on 133 dairy herds in four dairy regions (Waikato, Taranaki, and north and south Canterbury) were interviewed between May and July 2009. They were asked to provide demographic and biophysical data about the farm, and to rate their attitude in relation to their own personality traits, management issues and priorities, and likely constraints affecting reproductive performance in their herds. Associations between demographic factors and attitudes, priorities and constraints were analysed using univariable and multivariable proportional-odds regression models. RESULTS:Farms in the regions studied in the South Island were larger, had larger herds and more staff than farms in the regions studied in the North Island. The farms in the South Island were more likely to be owned by a corporation, managed by younger people or people who had more education, and the herds were more likely to be fed a higher percentage of supplementary feed. The majority of KDM rated the current genetics, milksolids performance and reproductive performance of their herds as high or very high, and >70% believed that the reproductive performance had remained the same or improved over the preceding 3 years. Despite this, improving reproductive performance was the most highly rated priority for the next 3 years. The constraints considered most likely to have affected reproductive performance in the last 2 years were anoestrous cows, protracted calving periods, and low body condition scores; those considered least likely were artificial breeding and heat detection. Of the variables examined related to attitudes, priorities and likely constraints, there were significant differences between region for 10/40, and with age and occupation of the KDM for 24/40 and 5/40, respectively (p<0.05). CONCLUSIONS:The majority of KDM reported the current reproductive performance of their herds to be high or very high, yet rated improving reproductive performance as a very high priority for the next 3 years. Mismatch between perceived and actual performance may result in reduced uptake of extension programmes designed to improve performance, and accurate benchmarking may help increase uptake and engagement. Further work is needed to determine whether the attitudes and perceptions about performance of farmers affect the likelihood of changes in their management behaviour which translate to measurable change in the actual reproductive performance of their herds. The variation in attitude, priorities and perceived constraints among age groups and region indicates that design of extension programmes may need to vary with these demographics.

Deferred grazing is a commonly used tool to manage feed surpluses. The effect of deferred grazing on pasture nutritive value and productivity was quantified in a split-paddock trial on three hill country farms in Waikato and Bay of Plenty from October 2018 until May 2020. Livestock were excluded from the deferred pasture between mid-October 2018 and March 2019. Thereafter, both treatments were rotationally grazed in common with cattle or sheep depending on the farm. Total annual dry matter production was 15% greater in the deferred than grazed treatment for the 12 months after deferring (8.9 vs 7.7 t DM/ha, P<0.05). Metabolisable energy (ME) values at the end of the deferred period were lower in the deferred than grazed treatment (P<0.01) but similar in both treatments thereafter. The content of legumes other than white clover (Trifolium repens) was higher in deferred than grazed pastures in spring 2019 on one of the farms (treatment × farm interaction P<0.05). Ground cover of perennial ryegrass was greater and the area of bare ground smaller, in the deferred than grazed treatment on three of five occasions from after the beginning of the deferred period until up to 8 months after deferring (P<0.05). There was no difference between treatments in decomposition and stabilisation of organic matter (P>0.05). The topsoil water content was higher in the deferred than grazed treatment for 12 months after deferring. In comparison to regular grazing between October and March, deferred pastures provided drought feed in autumn 2019. Pasture productivity was increased after the deferred period without negative impacts on ME.

A 2-year trial evaluated the herbage production of a number of selected subterranean clover (Trifolium subterraneum L.) cultivars and lines. Seedlings were transplanted into small plots on a cultivated area of less than 5° slope. Morphological characteristics, spring herbage production, isoflavone content, and summer/autumn seedling emergence were measured. Of the cultivars evaluated in this trial, only 'Denmark' proved to be an improvement on 'Tallarook', and this was only on the basis of early-season growth. However, a number of lines in this trial stood out in terms of their growth during the spring period and their high level of seed production. They included AK 664, WS 1436, and WS 536. Herbage harvested over 3 months from pure swards exceeded the equivalent of 2700 kg DM/ha, and seed production exceeded 7000 seeds/m 2 . These lines also had tissue formononetin levels less than 0.20% of dry weight. These results will be combined with those from previous persistence trials to determine those lines suitable for further cultivar development.

Lake Taupo is a high quality lake in the centre of the North Island, New Zealand. Local government aims to control nitrogen (N) inputs into the lake to preserve lake water quality. In this paper we discuss the implications of this policy for land use and farm management in the Lake Taupo catchment. To do this we used a case study approach, based on a typical farm, to examine the effects of stocking density and management system on farm cash surplus, farm capital value and nitrate leaching. The study showed that intensification of land use is a profitable option for farmers and any restrictions on land use in the Lake Taupo catchment will have large effects on the profitability and value of existing farm businesses. Farm systems can be adapted to reduce N leaching, however the options that we studied all resulted in a decrease in farm cash surplus. Further evaluation and experimentation on new systems is required. Rules that control farm activities in an attempt to control N leaching may not result in the gains desired owing to legitimate adjustments that farmers may make to re-optimise their farm business. Keywords: economic evaluation, farm systems, modelling, nitrate leaching, water quality

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