Diversifying farm activities can reduce the risk of agricultural production. Diversifying the type and proportion of pasture species grown was explored as a risk management option for dairying, and showed that there may be benefits of increased pasture growth rates at critical times of the production year, but the variability of the growth rate was not reduced.

Hot weather negatively impacts on the well-being and performance of dairy cows. To address this, cooling infrastructure can be provided to the cows, where the present study found that access to shade pre-milking on a pasture-based automatic milking system was linked with increases in milk production and cow comfort. These findings will allow farmers to improve the production and well-being of their cows (without requiring additional labour), thereby improving the profitability of their farms.

The ability of electrical conductivity to detect clinical mastitis is variable in automatic milking systems. This study has evaluated a range of indexes and algorithms created from quarter-level electrical conductivity data for early detection of clinical mastitis, but could not achieve the required accuracy. Incorporating other information related to milk yield may increase accuracy of detection and the ability to detect the early onset of mastitis.

The cows exposed to a sudden increase in temperature displayed the characteristic physiological responses of short-term heat acclimation. These results indicated that the conditions imposed on the cows in the controlled-climate chambers were sufficient to induce moderate heat-stress responses and adversely affected production in the lactating dairy cow. Following the heat challenge in controlled-climate chambers, the cows experienced a period of metabolic recovery as there was a delayed effect between the return to baseline feed intake and the return to baseline milk yield.

A lot of effort has been made by the Thai government and cooperative organisations to develop dairy farming in Thailand. We estimated genetic parameters and breeding values for milk production and milk composition from three government dairy cattle farms in Thailand. The results suggest that selective breeding using estimated breeding values can be used to enhance the performance of Thai cattle.

Pastoral livestock-production systems are under scrutiny, with farmers being required to reduce environmental impacts and to enhance biodiversity and animal welfare. Creating synergies between grazing decisions by animals and farmers offers greater benefits to the animal, the farm, and the environment than do simple management approaches based on managing for single components of the system. We envisage a more holistic approach to managing grazing based on recent advances in the understanding of the nutritional ecology of grazing animals.

The pasture yield benefits available from including white clover in mixtures with perennial ryegrass are often overlooked. Ryegrass monocultures were compared with mixtures in experiments across multiple environments and managements in New Zealand, revealing a mean yield advantage of 2.3 t DM/ha per year to mixtures. Management strategies to sustain a threshold of 20–30% clover in mixtures are described.

The inclusion of canola meal in a ration was investigated to determine its effect on intake and feeding behaviour. Experimental results indicated that the inclusion of canola meal in a ration increased pasture and total eating time, but there was no effect on pasture intake, as pasture allowance was low. The present research has implications for future investigations into the use of protein supplements in mixed ration feeding systems.

An important goal in New Zealand dairy systems is to increase production while achieving environmental targets associated with lower nitrate leaching from soils. A major contributor to leaching is the amount of nitrogen in the animals’ diet; therefore, one approach is to identify pastures that grow more and also have a lower nitrogen content. Results found there were no benefits in using herbs instead of grasses for reducing nitrogen intake in livestock in an irrigated Canterbury environment.

Whole-system studies comparing perennial ryegrass cultivars allow information from small plot trials to be validated, giving farmers confidence to invest in the use of new cultivars. A small number of whole-system studies have been published but results are not consistent. Despite the cost and complexity, there is a need for whole-system studies to be undertaken to explain where benefits in animal performance from improved cultivars come from.

Estimating the amount nitrogen (N) excreted in urine patches on grazed pasture requires samples of urine. This experiment identified the diurnal variation in urine N concentrations, which were lowest at milking times and highest mid-morning or early evening. For accurate estimates of the daily mean urine N concentration, sampling should include times of the day that are representative of both low and high concentrations.

Cows were fed diets comprising three different pasture allowances with one of four different amounts of mixed ration. Cows grazing the highest pasture allowance had greater intakes of pasture, but they did not have higher yields of milk than cows on more modest pasture allowances. These results will enable farmers to better optimise feeding systems that combine both pasture and mixed ration.

Australian and New Zealand dairy farmers have been increasingly exposed to volatility in market prices as well as climate variability, and changing regulation and consumer demand. Systems research plays a key role in testing different options for farmers to maintain profitability despite these challenges. There is need for research to fore-sight future risk and challenges, as well as opportunities, and working collaboratively with dairy farmers to increase knowledge transfer and adoption of positive research outcome.

Nutrient losses to the environment can be caused by dairy cows grazing crops over the winter period. The aim of the study was to document the prevailing wintering practices in the Canterbury region, with results indicating a reliance on kale and fodder beet located off the dairy farm. This information could be used to identify opportunities for reducing nutrient losses and as a base for evaluating practice change in the future.

The profitability of a dairy business in northern Victoria from 2003–2004 to 2014–2015 was compared with the performance of other dairy and non-agricultural investments. The analysis showed the farm performed well relative to other dairy businesses in Victoria, and alternative investments, such as shares, bonds and property. Compound annual return to capital over the 12 years was 12.4% (real), with over half the return from the farming operation and the remainder from owning assets that appreciated in value.

Growing consumer awareness and the expected expansion of the Asian dairy sector may increase pressure to find alternatives to palm-kernel expeller (PKE) as a supplementary feed for dairy cows in New Zealand. We examined the possibilities of domestically grown barley as a PKE replacement in Southland. The farm-scale framework was capable of exploring some of the farm and regional production, economic and environmental implications from such replacement.

Spring-calving pasture-based dairy systems have the flexibility to milk the cows for longer into autumn if there is sufficient feed or if it is profitable to buy supplement. To prevent negative impacts on the following year’s performance, farmers must ensure that cows reach a target body condition by their next calving date, and that there is sufficient pasture available for the following year. Possible options were modelled with a decision-support tool to allow farmers and advisors to interactively consider the profitability of those options, while ensuring no negative impacts on the following year.

Do new buildings and more cows make a New Zealand dairy farm more profitable? Using basic economic principles, and recent milk prices and farm costs, the present study found that limited intensification can improve profitability, but making a farm highly intensive seldom would. This work is important because of growing economic and environmental constraints on dairy farming.

Perennial ryegrass breeding efforts have focussed on improving pasture feed quality; however, the gains in farm profitability that this has delivered are not known. The feed quality characteristics of 24 perennial ryegrass cultivars were compared; genetic gains in whole-pasture feed quality have been delivered to dairy farmers through the development of later-flowering and tetraploid cultivars. The gains in pasture feed quality have the potential to deliver economic benefits in the range of NZ$54 to NZ$232/ha.year to New Zealand dairy farmers.

Chronologically fixed periods are used to define grazing intervals in the management of tropical grasses with rotational stocking; however, the growth rate of the grass is influenced by edaphoclimatic conditions. The aim was to examine the effect of variable grazing intervals, defined when the canopy reached 95% light interception. Milk yield per area increased ~28% when variable grazing intervals were utilised. This demonstrates that management strategies that respect the morphophysiological traits of forage species can be more productive.

In perennial ryegrass pastures, it is well established that dairy cows select a diet that differs from the nutritive characteristics of the pasture on offer, but less is known about this for other temperate perennial grasses. In the present study, cows selected a diet higher in crude protein than the pasture on offer, but less so for other nutrients, and this was correlated with the vertical distribution of nutrients within the plant. These results assist in developing grazing guidelines for cocksfoot, tall fescue and prairie grass.

Increasing the amount of crude protein in a dairy cow’s diet can increase intake and milk yield, yet the fate of the extra protein and the nitrogen-use efficiency has not been quantified. In the present experiment, the addition of canola meal, as a source of extra protein, increased intake but resulted in poorer nitrogen-use efficiency and more nitrogen being excreted. This indicated a need to find a balance between the benefits of feeding extra protein and the cost of wasted nitrogen.

Will increasing species diversity in perennial ryegrass- or tall fescue-based swards benefit herbage production on dairy farms? Different species mixtures were compared to determine whether including other forage species in traditional grass–clover swards would improve total herbage production or production at key times during the farming season. Perennial ryegrass-based swards produced more than did tall fescue-based swards, but increasing sward diversity did not consistently improve production and was likely to be related to climate. While some species showed potential to improve production, this must be balanced with considerations of how increasing sward species diversity affects sward management.

Strategies to increase herbage dry matter (DM) production are sought for dairy systems. Compared with perennial ryegrass pasture, a diverse pasture containing legumes and herbs have different grazing requirements that can affect regrowth, persistence, and nutritive value. Options to manage diverse pastures for improved pasture production and animal production were investigated using conventional grazing or lax grazing. Using lax grazing to manage diverse pastures in spring is unlikely to provide milk yield benefits.

There is a wide range of nitrogen and phosphorus losses from Australian and New Zealand dairy farms that could impair water quality. To meet voluntary and regulatory requirements to decrease nitrogen and phosphorus losses we tested a generalised approach to mitigation (priority given to those that are easy to implement) and found that phosphorus could be mitigated quite cheaply, but nitrogen reductions required more measures, some of which are costly.

The global livestock sector contributes a significant share to anthropogenic greenhouse gas emissions. The aim of this study was to examine the effects of supplementing sunflower oil on methane (CH₄) emissions from lactating cows grazing tropical pasture. Methane emissions decreased about 20% when cows were supplemented with sunflower oil. This demonstrates potential for mitigating CH₄ emissions without negatively affecting cow milk yield or composition. To be effective, mitigation actions need to be global.

Grape marc is composed of the skins, seeds and stems of grapes after they have been pressed for wine, and has been shown to reduce methane emissions when fed to dairy cows. A range of grape marc samples were evaluated for their potential to reduce methane emissions if used as a feed additive for dairy cows. There was a wide range of results, but grape marc that had been sourced fresh proved to be the most promising.

Fodder beet contains high concentrations of readily fermentable carbohydrates. Feeding fodder beet to dairy cows might alter rumen fermentation and consequently methane emissions. Feeding fodder beet in pastoral systems at ~50% and ~20% of the diet of dry and lactating dairy cows, respectively, decreased methane emissions compared with feeding forage kale and pasture alone.

Moisture deficit reduces growth of perennial ryegrass in many New Zealand dairy pastures. In a semi-controlled glasshouse study, we found the effects of previous moisture deficit on four ryegrass cultivars were greatest during the recovery period when moisture stress was alleviated. Results imply that avoiding overgrazing immediately after drought is just as critical for recovery as is management during a drought.

Recent research from Europe has suggested that concentrations of trans octadecenoic acids in milk fat may be used to predict methane emissions from dairy cows. Data from seven experiments involving 23 different diets and 220 observations on milk fatty acids were examined for potential to predict methane emissions. It was concluded that concentrations of trans isomers of C18:1 have limited potential to predict methane emissions, yields or intensities of dairy cows.

Lactation benefits the bovine offspring, but also implies numerous physiological challenges for the dairy cow. The present review addresses the latest findings on metabolic and endocrine adaptation mechanisms to lactation, their interaction with the offspring and the maternal immune competence, and considers the specifics of pasture-based systems. Recent developments in precision livestock farming technology are capable of detecting health disorders early and maintaining animal well-being.

Mycoplasma bovis is a major disease-causing agent in cattle causing significant economic losses to the cattle industry. Due to the lack of effective treatment measures, early detection of this disease agent in a cattle herd is paramount. This review focuses on the past and present improvements in the diagnosis of disease caused by Mycoplasma bovis in cattle.

Selection for heat-tolerant dairy cattle has become important, especially in the global warming context. We developed a tool that enables farmers to make selection decisions of animals that leads to improvements in heat tolerance and profitability simultaneously. The use of the tool will contribute to improving milk production and welfare of animals, especially in warm regions.

While mastitis in dairy cows is costly, affects the quality of milk and reduces milk production, internal teat sealants are used in mature dairy cows to mitigate these effects. Previous studies show internal teat sealant (ITS) use reduces mastitis in heifers; in addition to this effect, we saw an association between using ITS and improved milk production. Due to the study design we cannot provide assertion that the changes were a direct result of the ITS treatment; however, there is enough evidence to warrant further investigation in a prospective, controlled study.

The efficiency of dietary energy and nitrogen use by cows is a high priority for dairy industries. The partitioning of energy and nitrogen in cows selected for high or low efficiency was highly variable. The results of these experiments suggested that selection for efficiency in growing dairy heifers may lead to a greater proportion of the diet being partitioned to milk and less to the waste products of heat energy and nitrogen excretion.

Afternoon herbage allocation is a management to match herbage supply to the diurnal grazing pattern for dairy cows. We found that perennial ryegrass cultivars reacted differently to this management in terms of nutritive value and nitrogen-use efficiency of dairy cows. Therefore, pastoral dairy production systems would potentially benefit from afternoon herbage allocation using the right perennial ryegrass cultivar.

Rate and extent of starch degradation in the rumen is an important factor affecting milk production responses in high-yielding dairy cows. We compared starch degradation in the rumen of five concentrates relevant to Australian dairy farmers. Results showed that maize grain has the slowest rate of starch degradation, followed by sodium hydroxide-treated wheat and Maximize (a commercial pellet), with wheat and oat starch being rapidly degradable.

In Australia, there is interest in milking cows for longer than the traditional 300 days. During a 567-day experiment with lactating dairy cows, the partitioning of nitrogen (N) in the second year of an extended lactation was different from that in the first year, N-use efficiency was negatively related to N intake and days in milk, and adding grain to the diet increased total N intake but decreased N-use efficiency.

A priori knowledge of seasonal pasture growth rates helps livestock farmers estimate likely pasture availability and thus plan their feed budget. We compared pasture growth rates generated using climate forecasts derived from either historical archives or from the global circulation model POAMA. Hindcast growth rates (retrospective forecasts) were simulated using posterior weather data and were used as a surrogate for actual growth rates. We found that (1) statistical methods of comparing forecast data with hindcast or measured data are important, particularly if the comparison is made between a distribution of points and a single value, (2) 1-month growth-rate forecasts have less uncertainty than forecast durations of 2 or 3 months, and (3) there is little difference between growth rates simulated using climate data from either historical records or from global circulation models.

The use of pasture measurement tools and decision-support systems for grazing management remains limited on New Zealand dairy farms. Perspectives of farmers, rural professionals, farming-system specialists and software developers were analysed to understand how decision support-tool design could be matched with farmer practice. The research highlighted a need for flexible tools incorporating differences in user goals, decision making, mobility and desired outputs. Key attributes identified were seasonality, simplicity, ability to trial before purchase, flexibility in application and scalability to match farm systems.

The use of individualised feeding has increased within New Zealand dairy-farm systems in the past decade; however, little information exists on farmer motivations, practices, perceptions and challenges. A survey and interviews were conducted with farmers and farm consultants throughout New Zealand to explore these themes. Farmers using individualised feeding systems strongly believed that there was value from this investment, particularly in feeding individual cows or mobs within a herd with minimal additional effort, but evidence of profitability was lacking and there was insufficient information available on optimum feeding strategies.

Eight Australian robotic milking farms were monitored to understand current and potential system performance. Despite a wide range in farm performance, the actual milkings, cows, milk yield and milking time could potentially be increased by a maximum of ~60%. Given the high cost of the equipment, if this potential maximum was achieved, the technology could become more attractive to dairy farmers and could increase the viability of existing installations.

The ability to measure, monitor and detect changes in the behaviour of cattle will assist in improving individual cow health and performance. This study tested the accuracy of a new generation of the SCR HR-LDn activity and rumination monitoring system for grazing cows. The results showed that the device quantified the time cows spent ruminating, grazing and resting with high to very high levels of accuracy.

The present study demonstrated the capability of a lifetime nutrient-partitioning model for simulating genetic variation in production potential of Australian Holstein cows. The model could accurately predict the performance curves of bodyweight, milk protein and milk lactose concentration, while milk yield, milk fat concentration and body condition score were satisfactorily predicted, and the prediction of dry-matter intake was promising. It is suggested that the model can be further developed to simulate the effects of genetic and management strategies on production and efficiency of individual cows.

An investigation to determine whether heifers can be trained to respond to a sound to seek out a feed reward has shown promising results. The heifers were more likely and quicker to respond to the sound when they were called as a group rather than as individuals. The study suggests that voluntary trafficking could be encouraged through animal-mounted calling devices.