Grass nitrogen (N) concentrations of dairy grasslands are higher on peat soil than on mineral soils. This can lead to increased N losses to air and water from dairy farming systems on peat soils. Our hypothesis was that the use of low-N perennial ryegrass (Lolium perenne L.) genotypes could be a means to lower grass N concentrations, when grown on peat soils. Our objective was to determine whether perennial ryegrass populations with different shoot tissue N concentrations, recorded on a sandy soil, would show different shoot tissue N concentrations and N use efficiencies (NUE) or N uptake efficiencies (NUptE) when grown on a peat soil. First, a pot experiment lasting 62 days was carried out with nine diploid and seven tetraploid populations, followed by a field experiment with two diploid and two tetraploid populations and a control lasting 30 months. Both experiments had three N fertilization levels. In the pot experiment, populations explained 3% of the variation in shoot tissue N concentration among tetraploids, 5 and 7% of the variation in NUE among diploids and tetraploids and 12% of the variation in NUptE among diploids. In the field experiment, populations explained 44% of the variation in NUptE. A higher NUE coincided with lower shoot tissue N concentrations among tetraploid populations in the pot experiment. We conclude that there is potential to alter the shoot tissue N concentrations of perennial ryegrass grown on peat soil, via selection for shoot tissue N concentrations and NUE.

The Dixit entry/exit real option model was applied to the entry/exit decisions of New York dairy farmers. For the cost structure of a 500-cow farm, the entry milk price is $17.52 per hundredweight (cwt) and the exit milk price is $10.84. For the 50-cow farm cost structure, the entry price is higher at $23.71 per cwt, and the exit price is also higher at $13.48. If infinite numbers of representative farms enter and exit at these prices, the price of milk should range between $13.48 and $17.52 per cwt.

This study evaluates the environmental performance of northeastern U.S. dairy operations that differ in size using a directional output-distance function that measures the joint production of milk and emissions while incorporating a four-way error approach that captures farm-size heterogeneity, transient and persistent technical efficiency, and random errors. For the emission component, a comprehensive pollution index is generated that incorporates three major sources of pollution in dairy farming: fuel, fertilizer, and livestock. Computed shadow prices and Morishima elasticities of substitution reveal that large dairy operations are environmentally inefficient compared to their smaller counterparts.

Increasing input self-sufficiency is often viewed as a target to improve sustainability of dairy farms. However, few studies have specifically analysed input self-sufficiency, by including several technical inputs and without only focussing on animal feeding, in order to explore its impact on farm sustainability. To address this gap, our work has three objectives as follows: (1) identifying the structural characteristics required by specialised dairy farms located in the grassland area to be self-sufficient; (2) analysing the relationships between input self-sufficiency, environmental and economic sustainability; and (3) studying how the farms react to a decrease in milk price according to their self-sufficiency degree. Based on farm accounting databases, we categorised 335 Walloon specialised conventional dairy farms into four classes according to their level of input self-sufficiency. To this end, we used as proxy the indicator of economic autonomy – that is, the ratio between costs of inputs related to animal production, crop production and energy use and the total gross product. Classes were then compared using multiple comparison tests and canonical discriminant analysis. A total of 30 organic farms – among which 63% had a high level of economic autonomy – were considered separately and compared with the most autonomous class. We showed that a high degree of economic autonomy is associated, in conventional farms, with a high proportion of permanent grassland in the agricultural area. The most autonomous farms used less input – especially animal feeding – for a same output level, and therefore combined good environmental and economic performances. Our results also underlined that, in a situation of decrease in milk price, the least autonomous farms had more latitude to decrease their input-related costs without decreasing milk production. Their incomes per work unit were, therefore, less impacted by falling prices, but remained lower than those of more autonomous farms. In such a situation, organic farms kept stable incomes, because of a slighter decrease in organic milk price. Our results pave the way to study the role of increasing input self-sufficiency in the transition of dairy farming systems towards sustainability. Further research is required to study a wide range of systems and agro-ecological contexts, as well as to consider the evolution of farm sustainability in the long term.

This paper uses recent survey results from almost 1000 dairy producers in northeastern US to analyze farmers’ perceptions of barriers to the adoption of rotational grazing [management-intensive grazing (MIG)] as a means for feeding their dairy herds. The survey found that approximately 13% of dairy producers in the region were using MIG during the 2006 growing season. Approximately 40% of farmers surveyed were using a confinement feeding operation where the milking herd does not graze at all and close to 47% were using a traditional system that involved some pasture forage for the milking herd. Regardless of the popular sentiment that increased information and technical assistance is needed in the field, producers more frequently report a series of other barriers as being greater obstacles to the adoption of MIG. Farmers using confinement feeding tended to see each of the barriers presented as being more significant obstacles than did other farmers. Farmers with higher debt ratios and higher milk production per cow were more likely to view the financially related barriers (decreased milk production per cow, cash flow and farm profits) as significant obstacles.

Reproductive performance has recently been a growing concern in cattle dairy systems, but few research methodologies are available to address it as a complex problem in a livestock farming system. The aim of this paper is to propose a methodology that combines both systemic and analytical approaches in order to better understand and improve reproductive performance in a cattle dairy system. The first phase of our methodology consists in a systemic approach to build the terms of the problem. It results in formalising a set of potential risk factors relevant for the particular system under consideration. The second phase is based on an analytical approach that involves both analysing the shapes of the individual lactation curves and carrying out logistic regression procedures to study the links between reproductive performance and the previously identified potential risk factors. It makes it possible to formulate hypotheses about the biotechnical phenomena underpinning reproductive performance. The last phase is another systemic approach that aims at suggesting new practices to improve the situation. It pays particular attention to the consistency of those suggestions with the farmer’s general objectives. This methodology was applied to a French system experiment based on an organic low-input grazing system. It finally suggested to slightly modify the dates of the breeding period so as to improve reproductive performance. The formulated hypotheses leading to this suggestion involved both the breed (Holstein or Montbéliarde cows), the parity, the year and the calving date with regard to the turnout date as the identified risk factors of impaired performance. Possible use of such a methodology in any commercial farm encountering a biotechnical problem is discussed.

Attaching the milking machine to the cow is the last remaining major repetitive task that the worker in a modern milking parlour has to perform. Several groups of research workers are developing robotic systems for this purpose. The task for the robot of locating the cow's teats and attaching the machine is complicated by morphological differences between cows and the need to allow the cow freedom to move during the operation. This paper reviews the progress that has been made.

Studies on decision-making processes are generally aimed at identifying farmers' needs and predicting farmers' reactions to technical innovations. In the present paper we study these decision-making processes, with reference to dairy farms, to build a whole-farm computer model (WFM) which simulates farmers' actions. In this study, (i) a multi-tool and multi-step methodology is proposed, which can also be qualified as an iterative and interactive methodology to reveal decision rules and (ii) a generic structure to formalise how action is conducted, termed ‘structure for action modelling’ (SAM). In the case of forage crop-dairy cattle systems, we have tested the current methodology to capture the decision rules and the SAM to represent action concerning farm management. An ‘immersion’ approach, inspired by the ethnographic approach has been adapted to access operational technical decisions (taken on a daily basis). This study helped in understanding how detailed and large approaches can be complementary and can facilitate identification of what can be generalised in a conceptual model. To define the generic structure (SAM), a set of descriptive variables concerning technical operations has been selected. The conceptual model generated is composed of decision rules reconstructed by researchers with farmers' committed participation. The validation method is based on participatory approaches and on comparing of actions simulated by the model with practices on the ground. Not contesting the fact that farmers plan their action, this study also revealed the importance of adjustments in action. For example, 20 to 55% of the time the planned food ration is not distributed to the milking cows because of forage unavailability. We also discuss how this structure can facilitate integration of decision mechanisms in biophysical models and how such an integration of adjustment decision rules can produce more realistic simulations of technical actions. Error of biotechnical evaluations done by the WFM is reduced from about 25% to about 10% with the application of the proposed method.

Changing from a conventional livestock production system, based on fertilized grass swards, to an organic management system requires the establishment of legume-based swards to replace the purchased fertilizer nitrogen. This paper reviews experimental-based research on both the comparative economics of legume-based systems and grass swards and also the economic advantage that forage legumes confer on organic systems. A methodology to determine the production costs and economic values of a variety of forage legume systems is outlined. The resultant methodology is then applied to experimental results from trials, conducted at a wide range of sites in northern Europe, to determine the comparative profitability of different legume-based systems of silage production under conventional management. The results indicate that potentially red clover (Trifolium pratense L.), and to a lesser extent white clover (Trifolium repens L.), and lucerne (alfalfa) (Medicago sativa L.), can produce higher profits per hectare than grass-based systems using high levels of nitrogen fertilizer. Galega (Galega orientalis Lam) and lotus (Lotus corniculatus L.) can, in certain circumstances, be economically competitive with fertilized grass swards, but would generally not be the forage legumes of first choice. From an economic standpoint, forage legumes are probably best grown in a mixture with grass. As some of the experimental sites involved organic treatments, the analysis has been extended to include an assessment of the comparative economics of organic systems of production based on forage legumes, relative to conventional grass-based systems. Thus, the third part of the paper is concerned with quantifying the economic advantage to organic systems conferred by forage legumes. The results indicate that, under careful management, their use for silage can produce higher profits per hectare for organic dairy systems than those obtained from conventional grass-based systems. While the relative performance of organic systems is strongly influenced by the price premium paid for organic milk, which has declined in recent years, not all the projected economic advantage of legume-based organic dairy systems is eroded by this trend. However, economic advantage is not enough to secure the widespread adoption of forage legumes. This will depend on technological developments and management practices which reduce the risks associated with both more difficult crop establishment and higher nitrate leaching of forage legumes as compared to grass swards.