On-farm Monitoring Research Articles

Characterisation of farmers' soil sense and the implications for on-farm monitoring of soil health

If farmers are to determine whether their farm goals for resource condition are being met, and whether changes in farm management are leading towards a more sustainable farming system, then they need to be able to monitor these areas. Yet to date, an easy to use, practical and reliable method to be used by farmers to monitor trends in soil health has not been developed. This has been a consequence mainly of developing soil monitoring packages in isolation from the end user, and relying on 'expert' advice to guide farmers' management of the soil rather than empowering them to be more self-reliant in this area. This study sought to collaborate with farmers in the development of a soil health checklist. The research process acknowledged the importance of local conditions, farmers' existing knowledge on soils and their preferences for delivery and presentation of the final product. The study focused on farmers located in the north-west cropping region of New South Wales, Australia. This article reports on a prototype for a farmer's soil health checklist — the features they use, how they recognise those features, especially the language they use to describe a healthy and unhealthy soil, and finally the techniques they use to determine those features.

Trends of climatic potential and on-farm yields of rice and wheat in the Indo-Gangetic Plains

Rice and wheat are the two most important cereals in the Indo-Gangetic Plains (IGP) and are responsible for the food security of the region. To understand the productivity trends in the transects of the IGP: (1) the climatic potential yields of rice and wheat were simulated using a crop simulation modeling approach and (2) the long-term trends of potential and on-farm yields were compared. The potential yields of rice and wheat in the IGP ranged from 7.7 to 10.7 and 5.2 to 7.9 Mg ha −1, respectively. The upper transects of the IGP are more productive and yield decreases by 27% for rice and by 32% for wheat from transect 2 to transect 5. The rate of change in the potential yield trend of rice from 1985 to 2000 ranged from −0.12 to 0.05 Mg ha −1 per year. Negative yield trends were observed at six of the nine sites, four of which were statistically significant ( P<0.05). The decrease in radiation and increase in minimum temperature were the reasons for the yield decline. The potential yield trend of wheat, however, appeared to be stable. On-farm yields of rice also showed a negative trend but for wheat the trend was mostly positive. The adverse changes in the weather parameters and declining trends of potential and on-farm yields of rice should be taken as an indication of a future problem. Regular on-farm monitoring of crops and climatic factors is urgently needed for predicting problems and allowing measures to be taken to improve productivity.

Fecal Glucocorticoid Metabolites as a Measure of Adrenal Activity in Dairy Cattle

The feasibility of monitoring acute adrenal activity in New Zealand dairy cattle by measuring fecal glucocorticoid metabolites was investigated. Fecal glucocorticoid measurement has potential as an indicator of adrenal activity and animal stress because sampling is relatively noninvasive, does not interfere with the stress response itself, and permits on-farm monitoring. Fecal samples were collected from dairy cattle following ACTH challenge and exposure to stressors (novel environment, transport). Two immunoassays (11,17-dioxoandrostane enzymeimmunoassay and ICN corticosterone radioimmunoassay) were compared. Both assays detected increased immunoreactive fecal glucocorticoid metabolites following acute adrenal activity and the temporal relationship between plasma corticosteroids and fecal metabolite excretion was determined. The time to peak excretion was closely related to the transit time of digesta passing between the bile duct and the rectum and was affected by seasonal changes in feed intake and pasture digestibility. We conclude that measurement of glucocorticoid metabolites reliably indicates acute adrenal activity in dairy cattle and in combination with other physiological and behavioral measures has potential for monitoring health and welfare in dairy cattle.

On-Farm Monitoring of Soil Nitrate-Nitrogen in Irrigated Cornfields in the Ebro Valley (Northeast Spain)

The irrigated area served by the Canal d'Urgell, a semiarid region in the Ebro Valley (northeast Spain), presents problems of ground water pollution by nitrates. Corn (Zea mays L.) is widely grown in this area, and N fertilization in corn production is the major source of N input in the area, with application rates in excess of crop requirements. In this study, we monitored several commercial cornfields for soil NO3–N levels, crop N uptake, and crop productivity over a 2-yr period to quantify the relationship among soil NO3–N, N fertilizer rates, crop N use, and N loss through leaching. Monitoring soil NO3–N profiles showed that in some fields, soil NO3–N was transported to deeper layers in the soil during the growing season. In many cases, important accumulation of NO3–N was observed at the bottom of the soil at physiological maturity, increasing the risk of winter leaching. Soil N availability, calculated as preplanting soil nitrate test + N fertilizer, was neither related to plant N uptake nor final biomass and grain yield. In some plots, the occurrence of drought during the growing season was more decisive than soil-available N in explaining crop N uptake and grain yield differences. Available N levels found in the soil were above 370 kg ha−1 in all cases. Apparently, these levels were enough to satisfy the crop N requirements to achieve yields above 11 to 12 Mg ha−1. Overall data showed that there is an excess of N in the system.

Nutritional and grazing management of the dairy cow

AbstractThe pre-requisites for nutritional management of dairy cows are information about how much feed is being consumed as well as the nutrients that are being derived from that feed. Studies of feed intake and nutrient supply have been limited by difficult experimental techniques, particularly with grazing animals. The models derived from much earlier work are of only general applicability and there is a need for more site-specific information in order to benefit further from conceptual advances.We have adopted a different approach to studying herbage intake and nutrient supply, using less-invasive approaches as well as techniques that monitor more accessible aspects of these processes, such as jaw movements. These techniques have a major advantage, in addition to their value as research tools, because they could translate directly into commercial applications in on-farm monitoring. The use of diagnostics and behavioural recording is well explored in relation to health monitoring; here we argue for its potential to advance the application of knowledge about grazing and nutrition. We will illustrate this approach using our experiences in measuring grazing behaviour, using IGER behaviour recorders and assessing rumen function, using a series of non-invasive techniques.The IGER grazing behaviour recorder allows us to record jaw movements and hence grazing and ruminating time and bite dynamics. It also allows the recording of steps and is now being developed to incorporate non-invasive rumen state sensors. It has made a major contribution to our understanding of the foraging strategies of grazing animals and their effect on herbage intake. This technology has the potential to be developed for on-farm monitoring of foraging behaviour providing valuable inputs to the prediction of herbage intake, in decision support systems for grazing.The introduction of concept of protein degradation and microbial synthesis in the rumen are significant advances in protein rationing schemes. However, real progress has been limited because the lack of consistent experimental results means that models have little relevance to specific farm situations. We foresee considerable opportunities to monitor products of rumen degradation and synthesis that appear in milk (e.g. odd-chain fatty acids) or breath (e.g. sulphides).Taken together these technologies open the possibilities of an entirely new approach to nutritional management of dairy cows, with site-specific recommendations based on information gathered using new sensors that are incorporated into computerised feeding equipment and milking parlours.

Evaluation of a new cropping option using a participatory approach with on-farm monitoring and simulation: a case study of spring-sown mungbeans

In the northern Australian cropping region, mungbean is commonly sown as an opportunity crop, usually on low soil water after a winter cereal, and consequently has a reputation for being a low yielding, high risk crop. Yield prospects could be improved and risks reduced if it was sown on soils with a higher soil water content, for instance in spring after a winter fallow. However, there is a lack of experience and confidence in alternative roles for mungbean in the farming system. This paper describes a research approach involving researchers, farmers, advisers, and grain traders in which on-farm monitoring of spring-sown commercial crops and cropping systems simulation with APSIM were used to explore yield prospects for a spring-sown crop after a winter fallow. The key elements of the approach are: (1) identification of possible options through simulation of scenarios, (2) testing the new practice with innovative farmers, and (3) monitoring of the management and performance of commercial crops and comparing yields with benchmarks estimated with a model. In this case, after 2 years of on-farm testing, spring-sown mungbean has been shown to have a potential for high returns in the northern cropping systems.

Epidemiology and quality assurance: applications at farm level

Animal production is relevant with respect to farm income and the position of the sector in the market, but also with respect to the quality and safety of products of animal origin, related to public health. Animal production is part of a chain of food production. Therefore, producers have to take consumer expectations and demands in the domains of animal health, welfare and environment into account. A different attitude for production has to be adopted; this attitude can be visualized in good farming practice, GFP, codes. Farmers who focused on quality in its broadest sense need a system supporting them in their management and control of quality risks. Generally speaking, there are three systems for that purpose: GFP, ISO and HACCP. When the hypothesis followed relates to animal health being a feature of quality, or else welfare and environmental issues, then animal health care can be executed following quality control principles. The HACCP concept is well suited for quality control at farm level, involving risk identification and risk management. The on-farm monitoring and surveillance system of critical control points in the animal production process is the most important tool in this procedure. Principles for HACCP application as well as certification fitness of HACCP are elaborated upon. They are illustrated by using salmonellosis in meat-pig farms as objective for an HACCP approach. It is further discussed that, in addition to animal health and quality, animal welfare and environmental issues could also be covered by an HACCP-like system in an integrated manner. Ultimately, the HACCP modules could end up in an overall ISO certification.

Applying the concept of agrodiversity to indigenous soil and water conservation practices in eastern Kenya

Agrodiversity – the diversity of cropping systems, crop species and farm management practices has received increasing attention in recent years as a way of spreading risk and supporting food security in resource-poor farming systems. This paper discusses the dynamic aspects of indigenous soil and water conservation (ISWC) practices in a semi-arid part of Kenya. The objective is to show the range of sources of variability and diversity that prevail in this environment, the responses of farmers to this variability, and the way farmers' rationalise the heterogeneity of soil and water management practices. Methods used included participatory surveys and evaluations, on-farm monitoring, soil and rainfall data analyses, and questionnaire surveys. Sources of variability affecting cropping systems and land management practices included rainfall, soil fertility, farmer resource level and farm productivity. A decision-tree was developed to examine how biophysical and socio-economic variability affected farmers' choice of ISWC. Different ISWC structures dominated on sandy and stony soils, respectively. Low resource farmers tended to choose cheaper and less labour demanding techniques, and constructed smaller ISWC structures than better endowed farmers. The largest diversity of ISWC practices was found on newly-opened land with mixed soils. Moreover, on-farm productivity levels indicated that costly investments in SWC are unfeasible, as this would further increase the risk for negative returns to farming. The wider implications of the results are that SWC interventions in marginal areas should build on the existing agrodiversity and an understanding of the complex interactions between environmental and socio-economic factors that give rise to differences in farming systems and land management practices.

Managing mouse plagues in rural Australia

Author(s): Caughley, Judy; Donkin, Christine; Strong, Kevin | Abstract: The frequency of mouse plagues in grain-growing areas of Australia has increased since the advent of conservation farming practices. The increase has been particularly marked on the Darling Downs in Queensland where the frequency has trebled. Broad-scale monitoring is undertaken by the government to provide a general forewarning of plague. However, the authors found, from a questionnaire to farmers, that the incidence and timing of plagues is highly variable across the Downs. It is apparent that farmers need to monitor the numbers of mice on their properties at regular intervals if they are to undertake preventive management. Bait cards (pieces of paper soaked in canola oil) were tested as a method for on-farm monitoring. The average amount of each card eaten was significantly correlated with the density of mice, but because of the scatter of the data the authors recommend that the cards be used in conjunction with other signs of mice such as evidence of crop damage or of active holes and runways in stubble. Zinc phosphide bait was found to be a highly effective rodenticide if used at a time when food was scarce. If the bait receives registration, it would be a valuable tool to control mice in crops, especially prior to flowering. On the basis of these results, it was concluded that effective management of mice could best be achieved by minimizing food supply in stubble by efficient harvesting, regular monitoring, and by strategic baiting and stubble management when necessary.

On-farm monitoring of mouse-invasive Salmonella enterica serovar enteritidis and a model for its association with the production of contaminated eggs.

Mice (Mus musculus) captured in henhouses were assessed for the presence of salmonellae in spleens. Of 621 and 526 spleens cultured during the first and second years of collection, 25.0 and 17.9%, respectively, were positive for Salmonella enterica serovar Enteritidis. Contaminated eggs were cultured from nine houses during the first year of sampling, and for eight of these houses, serovar Enteritidis was recovered from the spleens of mice. Rank sum statistical analysis of positive mouse spleens indicated that three overlapping bacterial populations were present. This pattern of infection was repeated when lipopolysaccharide (LPS) variants were used to infect chicks, and the worst infections were associated with isolates producing high-molecular-weight (HMW) LPS. Mouse isolates were capable of producing unprecedented amounts of HMW LPS as indicated by compositional analysis of six isolates that swarmed across 2% agar, which is a type of bacterial migration dependent upon production of HMW LPS. It is suggested that serovar Enteritidis cultured from the spleens of mice caught on farms will detect strains that are enhanced in their ability to contaminate eggs, in part because they are able to produce HMW LPS.

An on-farm health monitoring of small ruminants: design, data and disease frequencies

The purpose of this study was to investigate the three-year incidence risk of various diseases of adult sheep and goats through on-farm herd health monitoring. The study was conducted, between April 1989 and March 1992, in three sheep and three goat herds with a rolling average total population of 704 adult animals. A system for on-farm data recording was established at the beginning of the study. The data were recorded on a specially-designed form by a veterinary stock assistant stationed on the farms, and collected by the investigating veterinarian during weekly visits. The results were used to determine the three-year incidence risk, three-year recurrence probability and time to first occurrence of various health problems. The associations between occurrences of various health problems were also determined. In the study herds, the three-year incidence risk was highest for diarrhoea, enterotoxaemia, cough/nasal discharge, laboured breathing with elevated body temperature, and abortion. Significant and strong associations were recorded between digestive disorders and death, and between respiratory disorders and death. Temporal occurrence of these health problems was recorded to determine the seasonality of occurrence. Areas for further research are discussed.

In vitro and in vivo studies of drug residue accumulation in pigmented tissues.

A procedure was developed to enable ready isolation of melanin granules from pigmented tissues of the bovine eye. The granules were used in a simple in vitro test to model the potential for a range of veterinary drugs to accumulate in melanin-containing tissues such as hair and the choroid/pigmented retinal epithelium (choroid/PRE) of the eye. The beta-agonists clenbuterol and salmeterol, but not salbutamol, showed appreciable binding, as did the beta-blockers propranolol and carazolol and the tranquillizers azaperone and xylazine. All of the natural and synthetic growth promoters tested gave rise to significant binding (17 beta-estradiol, testosterone, alpha-zeranol, diethylstilbestrol and 19-nortestosterone) but progesterone and 17 alpha-trenbolone bound to a lesser extent. To provide a preliminary indication of the validity of the model, animals were treated with clenbuterol for 21 d, to enable the assessment of accumulation in vivo. Clenbuterol was detected in choroid/PRE and hair at high concentrations from the last day of treatment (1779 ng g-1 and 424 ng g-1, respectively) until the end of the study period, 63 d later (512 ng g-1 and 483 ng g-1, respectively). These studies clearly indicate the wider potential for pigmented tissue analysis in monitoring for the use of veterinary drugs (particularly unlicensed substances) in food producing animals. Hair analysis may offer particular advantages for on-farm monitoring and in providing historic information.

Assessment of Different Bioassay Techniques for Resistance Monitoring in the Diamondback Moth (Lepidoptera: Plutellidae)

Topical application, leaf residue, and filter paper residue bioassay methods were used to assess the toxicity of permethrin and methomyl to larvae of the diamondback moth, Plutella xylostella (L.). The objective was to develop an on-farm insecticide resistance monitoring technique for diamondback moth that required only simple, inexpensive equipment and was easy to use. The results of tests using the three bioassay methods led to similar resistance ratios for three diamondback moth strains. Leaf residue and filter paper residue tests using discriminating concentrations could detect the relative susceptibility to permethrin and methomyl in three strains, indicating that both techniques were practical for on-farm resistance monitoring. Third instars were more suitable for the detection of resistance than fourth instars. A monitoring system incorporating concentrations f both the LC90 for susceptible diamondback moth and the recommended field concentration of insecticide is suggested to detect resistance at low levels and to help choose insecticides for the control of diamondback moth strains with higher resistance levels.

A rod-point technique for estimating botanical composition of pastures

A simplified point method, the rod-point technique, for determining pasture botanical composition was assessed against 3 other popular methods. It was over 100 times faster than the traditional cut and hand-separate technique for the same level of precision. The presence of bias in the rod-point technique was assessed by comparing its estimates with those obtained by the hand-separation method. The pasture was classified into 8 botanical components, and the rod-point technique was significantly different from the hand-separated method in 3 instances, but in each case so were the Levy-point and the dry-weight-rank methods or the dry-weight-rank method alone. The rodpoint technique is most useful in large grazing trials, on-farm pasture monitoring, and pasture surveys. It provides a simple alternative for estimating pasture composition, using low inputs of materials, time, and labour.

Monitoring reproduction using immunological techniques

Immunological techniques have been developed to monitor reproduction under practical conditions. Of these, techniques for confirmation of oestrus and diagnosis of pregnancy are of major importance. The milk progesterone test for dairy cattle and the oestrone sulphate test for pigs are considered and a recently developed novel cow side milk progesterone test is described. Owing to the rapid development of immunosensors for ‘real-time’ detection of an analyte, the application of immunosensors for on-farm monitoring of reproduction seems possible within a few years.

Pregnancy detection and litter size classification by estrone sulfate measurements in swine under farm conditions

Previous studies indicated a high correlation between concentration of estrone sulfate (E1S) in serum and number of conceptuses in swine when killed in early gestation. Litter size at birth has been less correlated. Because litter size at birth is the ultimate goal for use of such correlations, we determined the feasibility of on-farm monitoring of E1S as an aid to management. Our approach was to obtain blood from mated sows and gilts at a stage of gestation when this high correlation exists, predict whether the animal was pregnant, and if so, predict the litter size, and check the accuracy of our predictions at farrowing under farm conditions. Blood was obtained from 148 sows and gilts on one day ranging from Day 20 to Day 26 following estrus. Concentration of E1S was determined by radioimmunoassay (RIA). When the concentration of E1S on Day 20, Day 21, Day 22, Day 23, Day 24, Day 25, or Day 26 was above 300 pg ml −1, 300 pg ml −1, 300 pg ml −1,300 pg ml −1, 350 pg ml −1, 400 pg ml −1 and 450 pg ml −1, respectively, animals were considered pregnant, below that, not pregnant. The designation was correct in 126 cases (85%) based on records of estrus and farrowing. Twenty-one animals considered pregnant at Day 30 later were recorded as returned to estrus, whereas one animal classified and recorded as non-pregnant farrowed eight piglets. Concentration of E1S was used to classify animals as to estimated litter size. Animals with greater than 400 pg ml −1, 500 pg ml −1, 665 pg ml −1, 850 pg ml −1, 1040 pg ml −1, or 1750 pg ml −1 E1S on Day 20, Day 21, Day 22, Day 23, Day 24, Day 25, or Day 26, respectively, were classified as having eight or more fetuses; those with less than these concentrations were classified as having seven or fewer fetuses. Litter size classification was correct in 73% of cases at birth (approximately 90 days later). Litter size was higher than predicted in 15% and lower than predicted in 12% of cases. Concentration of E1S in early gestation was thus strongly related to pregnancy and to litter size and, further, can be used in a predictive manner to assist with management decisions.

The use of carbon dioxide insect traps for the collection of Ornithodoros erraticus on African swine fever-infected farms

The establishment of epidemiological studies of African swine fever involves the collection of large numbers of the soft tick, Ornithodoros erraticus, to assess the maintenance and spread of the disease in the semi-arid southern areas of Portugal. An on-farm monitoring system involving solid carbon dioxide trapping of ticks was used. This capture method proved to be both simple and effective when compared with manual collection. Both adult and stadial ticks were attracted by the traps making this method suitable for epidemiological surveillance studies of any disease which involves the Ornithodoros as a vector.

Sulfamethazine residues in swine: comparison of on-farm monitoring methods

Three sulfamethazine-residue detection methods were used to evaluate samples collected from five swine farms over a 12-month period. All cooperating farms included sulfamethazine in swine diets at various stages of production, for growth promotion or disease control, and followed recommended drug withdrawal periods. Swine finishing ration, swine urine, and swine serum from market-weight animals were tested monthly for the presence of sulfamethazine. Thin-layer chromatograph (TLC) analysis of swine urine was the gold standard by which three other test method-sample combinations were compared. Samples were analyzed for sulfamethazine using TLC (feed), competitive enzyme immunoassay (serum), and agar-diffusion swab test (urine). The relative sensitivities and specificities of sulfamethazine-residue detection for the three combinations were: (1) TLC analysis (27%, 94%); (2) competitive enzyme immunoassay analysis (58%, 59%); (3) agar-diffusion swab test (78%, 12%). None of the three methods tested was individually adequate for on-farm monitoring of sulfonamide residues. Sulfamethazine residues in swine urine were found on 43.3% of the monthly farm visits and in 19.7% of all swine tested.

On-farm monitoring of mating performance of single yearling Hereford bulls

Abstract The reproductive performance of 18 yearling Hereford bulls was monitored in detail to relate mating marks (from chinball harnesses) to subsequent pregnancy and calving results and calving dates. Single-sire mating groups with Hereford yearling heifers and cows at pasture (average 27 females per group) were monitored over 8 – 10-week mating periods in the springs of 1983 – 85. The herd was of interest because of a suspected problem with bull fertility. Over the 3 years, 520,10 of females put to the bull were marked in the first 3 weeks; 36% of those put to the bull calved in the first 3 weeks of calving. Over the whole calving period, 71 % of females calved, including those put to five bulls of low reproductive performance. Two of these were identified during mating, one with few mating marks (first 3 weeks) and one with a high return rate (Weeks 4 – 5). However, under the commercial beef farming conditions prevailing, the other three were not identified until pregnancy diagnosis. There was greate...