Real Farming Conditions Research Articles

The feeding system impacts relationships between calving interval and economic results of dairy farms

The calving interval (CI) can potentially impact the economic results of dairy farms. This study highlighted the most profitable CI and innovated by describing this optimum as a function of the feeding system of the farm. On-farm data were used to represent real farm conditions. A total of 1832 accounts of farms recorded from 2007 to 2014 provided economic, technical and feeding information per herd and per year. A multiple correspondence analysis created four feeding groups: extensive, low intensive, intensive and very intensive herds. The gross margin and some of its components were corrected to account for the effect of factors external to the farm, such as the market, biological status, etc. Then the corrected gross margin (cGMc) and its components were modelled by CI parameters in each feeding system by use of GLM. The relationship between cGMc and the proportion of cows with CI<380 days in each feeding group showed that keeping most of the cows in the herd with CI near to 1 year was not profitable for most farms (for the very intensive farms there was no effect of the proportion). Moreover, a low proportion of cows (0% to 20%) with a near-to-1-year CI was not profitable for the extensive and low intensive farms. Extending the proportion of cows with CI beyond 459 days until 635 days (i.e. data limitation) caused no significant economic loss for the extensive and low intensive farms, but was not profitable for the intensive and very intensive farms. Variations of the milk and feeding components explained mainly these significant differences of gross margin. A link between the feeding system and persistency, perceptible in the milk production and CI shown by the herd, could explain the different relationships observed between the extent of CI and the economic results in the feeding groups. This herd-level study tended to show different economic optima of CI as a function of the feeding system. A cow-level study would specify these tendencies to give CI objectives to dairy breeders as a function of their farm characteristics.

Lack of experimental evidence to support mcr-1-positive Escherichia coli strain selection during oral administration of colistin at recommended and higher dose given by gavage in weaned piglets

In this study, we assessed the selective effect of colistin administered orally to healthy weaned piglets harbouring an intestinal mcr-1-positive Escherichia coli strain. Maximum recommended dose and a higher dose often used in European pig farms were given by gavage. No selection of the mcr-1-positive strain was observed in our controlled conditions, irrespective of the dose. Further investigations in real farming conditions seem necessary.

Integrated farming systems for improving soil carbon balance in the southern Amazon of Brazil

Integrated farming systems (IS) are one of the main strategies of the Brazilian government to reduce or compensate for carbon emissions from agriculture with simultaneous improvement in production efficiency. The IS are agricultural production systems that combine crop, livestock and forestry activities in the same area. The aim of this study was to address soil organic carbon (SOC) stocks under two agriculture areas with IS, in comparison with one exclusively used as low-input pasture (Pasture). The IS consisted of growing forestry species (Eucalyptus urograndis) simultaneously with soybean (Glycine max) and aerobic rice (Oryza sativa) for 2 years when grain crops were followed by palisade grass (Urochloa bryzantha). The study was carried out in real farm conditions in the southern Amazon ecosystem, north of Mato Grosso State, Brazil. SOC stocks were measured to 1 m soil depth. Compared to Pasture, areas of higher SOC stocks were identified in IS under the tree lines below 0.3 m, where there was no soil N deficiency. Our results indicated that, under the local edaphic and climatic conditions of the study, IS with trees can promote SOC accumulation even in a short term, such as 3 years in this case study, if soil fertility constraints do not exist.

Combination of Agile Development and User Centered Design to Improve the Usability of a Beef-Cattle Farm Simulator

Abstract--- At the Faculty of Veterinary Science of the National University of Buenos Aires Center a Beef-Cattle Farm simulator called Simugan has been developed. Simugan allows users to experiment over a virtual farm in a simple and low cost way compared with real farm conditions. Increased number of user led to the identification of deficits in Simugan usability, as inconsistency problems with inputs and outputs were difficult to understand by novel users. Therefore, a combination of agile development and user centered design (AD&UCD) was applied to fix those identified problems. The results shown a high level of achievement with AD&UCD (94% of methodology required criteria) as reported in user interviews and evaluation tests.

Cost:Benefit analysis of insect net use in cabbage in real farming conditions among smallholder farmers in Benin

Insect net use provides a physical exclusion of pests as well as a microclimate change, thus increasing soil humidity, vegetable quality and yields in tropical conditions. This paper presents the findings of a cost:benefit analysis of this technology in real farming conditions compared to current insecticide practices. The surveys were conducted in Benin for cabbage production (Brassica oleracea L.) during two production cycles. There were almost no significant differences in costs between unnetted and netted cabbage for the two production cycles. The only factors that varied were farm gate prices, the number of cabbages marketed and their size. Improved yields contributed significantly to the higher cost:benefit ratio for netting protection. Insecticide costs significantly declined by 68%–95% when shifting from unnetted protection to netted protection and total operational and labor costs declined by 3%–40%. Insect net use generated threefold higher margins and an average 1:2.66 cost:benefit ratio compared to 1:1.58 for current practices. Overall, the netting technology displayed less variation for costs, yield, and cabbage quality than insecticides. The next step is to scale up the supply of marketed insect nets.

Speed advice for power efficient drawbar work

Abstract Tractor manufacturers already offer engine – transmission control systems in which the operator decides whether low fuel consumption or high output is the priority and let a control system provide engine and transmission management. Less sophisticated tractors, as well as older equipment, still rely on the operator awareness upon what driving parameters most enhance efficiency. The objective of this study is to analyse the effect of driving parameters, namely forward speed and engine speed on the overall power efficiency. The overall power efficiency of a tractor performing drawbar work is the ratio between the output power at the drawbar and the energy equivalent of the fuel consumed per unity of time. Experimental data obtained from tractor field tests in real farm conditions, within the range of 0.2–0.4 for the vehicle traction ratio (ratio of the drawbar pull to the total weight of the tractor), show that increments of 10–20% on the overall power efficiency can be obtained by throttling down from 2200 min −1 to 1750 min −1 (idle speed). The reduction in ground speed and therefore in the work rate, may be overcome by shifting up the transmission ratio.

Classification of real farm conditions Iberian pigs according to the feeding regime with multivariate models developed by using fatty acids composition or NIR spectral data

Multivariate Classification models to classify real farm conditions Iberian pigs, according to the feeding regime were developed by using fatty acids composition or NIR spectral data of liquid fat samples. A total of 121 subcutaneous fat samples were taken from Iberian pigs carcasses belonging to 5 batches reared under different feeding systems. Once the liquid sample was extracted from each subcutaneous fat sample, it was determined the percentage of 11 fatty acids (C14:0, C16:0, C16:1, C17:0, C17:1, C18:0, C18:1, C18:2, C18:3, C20:0 and C20:1). At the same time, Near Infrared (NIR) spectrum of each liquid sample was obtained. Linear Discriminant Analysis (LDA) was considered as pattern recognition method to develop the multivariate models. Classification errors of the LDA models generated by using NIR spectral data were 0.0% and 1.7% for the model generated by using fatty acids composition. Results confirm the possibility to discriminate Iberian pig liquid samples from animals reared under different feeding regimes on real farm conditions by using NIR spectral data or fatty acids composition. Classification error obtained using models generated from NIR spectral data were lower than those obtained in models based on fatty acids composition.

Farm-Level Performance of Genetically Modified Cotton

In this paper, the yield increases resulting from the cultivation of Bt cotton in Maharashtra, India, are analysed. The study relies on commercial farm, rather than trial, data and is among the first of its kind to be based on real farm and market conditions. Findings show that since its commercial release in 2002, Bt cotton has had a significant positive impact on yields and on the economic performance of cotton growers in Maharashtra. This difference remains even after controlling for different soil and insecticide inputs in the production of Bt cotton. There is also significant spatial and temporal variation in this‘benefit’, and much depends upon where production is taking place and on the season.

Farming options for The Netherlands explored by multi-objective modelling

Intensive agriculture in The Netherlands has a price in the form of environmental degradation and the diminution of nature and landscape values. A reorientation of farming is needed to find a new balance between economic goals and rural employment, and care for clean water and air, animal well-being, safe food, and the preservation of soil, landscape and biodiversity. The search for farm systems that meet such multiple goals requires a systematic combination of (a) agrotechnical, agroecological and agroeconomic knowledge, with (b) the stakeholders’ joint agreement on normative objectives, to arrive at conceptual new designs followed by (c) empirical work to test, adapt and refine these under real commercial farming conditions. In this paper explorative modelling at the whole farm level is presented as a method that effectively integrates component knowledge at crop or animal level, and outlines the consequences of particular choices on scientific grounds. This enables quantitative consideration of a broad spectrum of alternative farming systems, including very innovative and risky ones, before empirical work starts. It thus contributes to a transparent learning and development process needed to arrive at farm concepts acceptable to both entrepreneurs and society. Three case studies are presented to illustrate the method: dairy farming on sandy soils; highly intensified flower bulb industry in sensitive areas in the western Netherlands; and integrated arable farming. Trade-offs between economic and environmental objectives were assessed in all three cases, as well as virtual farm configurations that best satisfy specified priority settings of objectives. In two of the three cases the mutual reinforcement and true integration of modelling and on-farm empirical research appeared difficult, but for obvious reasons. Only in the flower bulb case was the explorative approach utilized to its full potential by involving a broad platform of stakeholders. The other two case studies lacked such formalised platforms and their impact remained limited. Three critical success factors for explorative modelling are identified: to cover a well-differentiated spectrum of possible production technologies; early timing of modelling work relative to empirical farm prototyping; and involvement of stakeholders throughout.

EXTENDING THE USE OF CROP MODELS TO STUDY PEST DAMAGE

Most crop growth models do not account for damage caused by pests. This limitation must be removed if the models are to provide useful predictions of production under real farm conditions. A generic framework was developed to couple pest damage of various types into the PNUTGRO and SOYGRO models for peanut and soybean, respectively. Coupling points were identified in the models for applying damage to leaves, stems, roots, pods, seeds, whole plants, and to the supply of assimilate. The resulting models were tested by simulating crops with measured pest damage levels for peanut (foliar disease) and soybean (foliar feeding insects) and comparing observed and simulated crop growth and yield results. This approach for coupling pests with crop models has potential for extending the practical applications of crop models to a broad range of problems.