RESEARCH DISCIPLINE
Statistical Analysis for Agricultural & Veterinary Sciences Research
Consulting for Field Trials & Animal Studies
Agricultural research statistical analysis for field and greenhouse trials, livestock feeding and health studies and herd records, with the treated unit identified as the plot, pen or herd, the blocks of the design respected and results prepared to your journal's standard.
No Commitment Required
Strictly Confidential
In-House PhD-Level Statisticians
Fixed Project Fee
Same-Day Response
Statistical Analysis for Agricultural & Veterinary Sciences Research
Agricultural research statistical analysis is the statistical design, analysis and reporting of experiments and surveys on crops, livestock and companion animals, from field and greenhouse trials to feeding studies, clinical veterinary trials and herd health records. Treatments are applied to plots, pens or herds rather than to single plants or animals, blocks absorb differences between soils and barns, and measurements repeat over a season, so a workflow that treats every animal as independent understates the standard errors, and one that analyzes a split-plot layout as a simple ANOVA tests the main-plot factor against the wrong error term. OnlineSPSS, a specialist statistical consultancy for academic, clinical and professional research, provides veterinary research statistics and agricultural experiment analysis through in-house PhD-level statisticians, who settle the experimental unit, the blocking and the covariance of repeated measures with you before any model is fitted.
WHEN TO ENGAGE
Statistical Support at Different Stages of Agricultural & Veterinary Sciences Research
Agricultural and veterinary researchers usually reach us at a point set by the season or the trial calendar, from the layout of plots to a reply to reviewers.
Laying Out a Field or Pen Trial You are planning a trial and need the treatments, the blocking, the number of plots or pens and the layout settled, so the design can be analyzed as intended once the season ends.
Analyzing a Completed Season Yields, weights or health records are collected, and the model for blocks, repeated visits and unbalanced pens needs to be chosen, run and checked.
Handling Animals Lost in a Trial Some animals were removed for illness or sold, pens are now unequal in size, and you need an analysis that keeps the pen as the unit and states what the losses could change.
Writing Up a Field or Feeding Trial The trial is finished and the paper needs adjusted treatment means with intervals, the number of pens or plots per treatment and methods text that follows the target journal's guideline.
RESEARCH CONTEXT
Research Designs and Data We Work With in Agricultural & Veterinary Sciences
Agricultural and veterinary data come from plots, pens, clinics and farms, and each source records a hierarchy of units that decides what counts as a replicate.
01
Field and Greenhouse Trials
Cultivars, fertilizer or other treatments applied to plots in randomized blocks or a split-plot layout, with yield and quality measured once or repeatedly.
02
Multi-Location and Multi-Year Trials
The same treatments repeated across sites and seasons, where location and year interact with the treatment and are treated as random or fixed by design.
03
Livestock Feeding Trials
Diets or supplements given to pens or groups of animals, with body weight and intake recorded weekly and some animals removed during the trial.
04
Clinical Veterinary Studies
Companion or farm animals treated in practices or clinics, with outcomes such as recovery or lameness scored by clinicians and clustered by practice.
05
Herd and Flock Health Records
Disease, mortality and production records from farms, where animals cluster within herds and risk factors are observed, not allocated.
06
Breeding and Genetic Evaluation Data
Pedigrees and performance records for related animals or plants, where relatedness breaks independence and breeding values come from mixed models.
METHODOLOGICAL CONSIDERATIONS
Statistical Issues We Consider in Agricultural & Veterinary Sciences Research
These are the checks made in agricultural field trial analysis before treatment effects are reported, since the unit and the error structure matter more than the choice of post-hoc test.
The Pen, Plot or Herd as Unit When a diet goes to a pen or a treatment to a plot, that pen or plot is the unit, however many animals or plants it holds. The number of pens, not animals, sets the degrees of freedom.
Blocks, Split Plots and Error Strata Blocks absorb field or barn gradients, and a split-plot has one error term for whole plots and another for subplots. The model carries each stratum so every factor is tested against its own error.
Repeated Measures Over a Season Weights, yields or milk records from one unit are more alike when close in time. The covariance structure is chosen from the design and checked, not left at the software default.
Pseudoreplication From Subsamples Several leaves per plant, samples per pen or tests per animal are subsamples. They are averaged or nested within the unit, since counting them as replicates overstates the evidence.
Unbalanced Data and Lost Plots Plots lost to weather leave unequal replication, so treatment means are reported as model-adjusted means and tests come from the mixed model, not from sums of squares that depend on term order.
Binary, Count and Proportion Outcomes Mortality, disease incidence, germination and lesion counts are not normal. They are modeled as proportions or counts, with random terms for pen or block and a check of overdispersion.
STATISTICAL METHODS
Methods Selected for the Research Question and Study Design
Each method family is chosen for the layout and the outcome of your trial, and the line under each title explains why it suits agricultural and veterinary data.
Longitudinal & Multilevel Analysis
Pens, blocks and farms enter as random effects, repeated weights or yields as correlated measurements, and generalized mixed models carry the same terms for counts and proportions.
Comparative & Hypothesis Testing
Completely randomized trials compare means by analysis of variance, block and split-plot layouts keep their own error strata, and a baseline covariate adjusts the comparison.
Regression & Predictive Modeling
Mortality, disease and germination are modeled as proportions and counts of lesions or parasites as counts, with overdispersion checked and random terms for pen or block.
Clinical, Survival & Epidemiological
Herd records and animal health outcomes are analyzed as incidence, risk and time to disease, with farms as clusters and risk factors reported as ratios with intervals.
Multivariate, Scale & Reliability
Body condition and lameness scores depend on the scorer, so agreement between observers is measured, and correlated soil, forage or phenotype variables are summarized by components.
Bayesian & Computational Methods
Plots lost to weather and animals removed from pens are handled with stated missing-data assumptions, and multiple imputation is used where lost values depend on recorded variables.
DELIVERABLES
Statistical Outputs Prepared for Your Research
The outputs follow the structure of a field or livestock trial, from the review of the layout to the programs that regenerate each table.
Data & Study Review The field plan or pen allocation, blocks, treatments, measurement dates and records of removed animals or lost plots are reviewed before modeling, so each value traces to its pen or plot.
Statistical Analysis The agreed block or mixed models with residual diagnostics, the covariance structure for repeated measures and sensitivity analyses with and without lost units.
Effect Estimates & Uncertainty Adjusted treatment means and differences with 95% confidence intervals, variance components for pen and block, and rates or proportions for health outcomes with their intervals.
Tables & Figures Treatment summary tables by pen or plot, means plots over time, a flow table of units allocated, lost and analyzed, and plots of treatment contrasts across sites.
Statistical Interpretation Findings are explained in agronomic or animal science terms within what the design supports, results from one site or season are not generalized beyond it, and the limits of unequal data are stated.
Analysis Files SAS programs, R scripts or SPSS syntax, with the trial layout and the covariance settings documented so that every table can be regenerated.
REPORTING
Reporting Agricultural & Veterinary Sciences Research
Livestock trials, veterinary observational studies, animal experiments and plant phenotyping each answer to a different guideline, chosen by design and species.
Randomized trials in livestock with production, health or food-safety outcomes report to REFLECT, an extension of CONSORT, and veterinary observational studies report to STROBE-Vet. Experiments on animals in research settings add ARRIVE 2.0, with the experimental unit and the handling of removed animals stated. Plant phenotyping experiments describe their design and conditions to MIAPPE. Field trials are described with the layout, the blocking and the model formula, including random terms, so another group could repeat the analysis. Each treatment effect is reported with its confidence interval, and the number of pens, plots or herds per treatment is stated beside the number of animals or plants.
ILLUSTRATIVE EXAMPLE
How the Analysis May Look in Practice
An illustration of how a pen-fed calf trial is analyzed at the level of the pen, with weekly weights and unequal pens.
ILLUSTRATIVE EXAMPLE · DAIRY CALF FEEDING TRIAL · UNITED STATES
An agricultural research station wanted to know whether a milk replacer with added protein increased the growth of dairy calves compared with the standard formula.
Calves lived in group pens of five, each pen received one formula, and calves were weighed weekly for eight weeks. A first analysis had treated each calf as an independent observation. The reanalysis plan was written before any growth estimate was looked at: the pen as the experimental unit, average daily gain from a mixed model with a random term for pen and an autoregressive covariance for the weekly weights, and starting weight as a covariate. Several calves were removed for illness during the trial, which left some pens unequal in size. They stayed in the model, and results without them were reported as a sensitivity analysis.
Outcome: The station received the difference in average daily gain with its 95% confidence interval, the pen-level variance, the flow of pens and calves for REFLECT reporting, a methods paragraph and the SAS programs.
This example does not describe a real client or project. We never share details of actual client work, in line with the confidentiality we promise every researcher. This illustrative example is included to show the type, scope, and standard of work involved in this kind of analysis.
RESEARCHER VOICE
What Researchers Say
Feedback from a veterinary researcher on a dataset that was not a textbook example, and on an analysis built around the actual study design.
“We contacted OnlineSPSS because our dataset was not a textbook example and we needed someone familiar with Agricultural & Veterinary Sciences. They focused immediately on the repeated or paired structure of the measurements, then built the analysis around the actual study design. The final output was concise and easy to use with the wider team.”
HOW WE ASSESS YOUR PROJECT
We Review Your Actual Research
Your assessment is based on a review of your actual research materials and analytical requirements, not a generic project category.
You Submit Your Project Details
Share whatever is available at the current stage, such as the research aim, protocol or proposal, dataset, variable list, manuscript or statistical requirements.
We Review Your Research and Define the Scope
Your statistically trained Research Coordinator reviews the materials to understand the study design, research questions, data structure, analytical requirements and expected deliverables. If clarification is needed, additional documents or information can be requested before the assessment is finalized.
Your Analysis Is Completed and Delivered
Once the scope and fixed project fee are agreed, the in-house statistician completes the work and the Research Coordinator remains the communication point through delivery, with the analysis, deliverables and timeline as agreed.
SOFTWARE
Statistical Software for Agricultural & Veterinary Sciences Research
Agricultural and veterinary analyses are run in the software your station or clinic uses, with mixed models in SAS or R, and files provided where applicable.
Statistical Support Within Your Research OnlineSPSS provides the agreed methodological, analytical, and statistical reporting support. The researcher or research team retains the scientific question, substantive interpretation, conclusions, and overall responsibility for the research.
FREQUENTLY ASKED QUESTIONS
Questions About Statistical Analysis for Agricultural & Veterinary Sciences
Short answers to what agricultural and veterinary researchers ask before sharing a trial, from pens as units and split-plot layouts to lost animals, confidentiality and the assessment.
What statistics are used in agricultural and veterinary trials?
Trials mostly rely on mixed models with block, pen or farm terms, covariance structures for repeated measures, and logistic or count models for mortality and disease, chosen by the layout and the outcome. Animal study data analysis for herd records adds incidence, risk and clustering by farm. Our Statistical Methods pages show how each family is applied.
Are animals in the same pen independent observations?
Not when the diet or treatment went to the whole pen, because the pen-mates then share one allocation and form one experimental unit. The answer changes when animals within a pen receive different treatments, for example through individual feeders or individual dosing: the animal then becomes the unit and the pen enters the model as a block. Pen-mates still share space, feed access and infections, so a term for pen is kept in either case.
Can you analyze a split-plot or repeated measures trial?
Yes. Split-plot, strip-plot, Latin square and repeated measures layouts are analyzed with a model that matches the randomization: each factor is tested against its own error term, and repeated weights or yields carry a covariance structure that is chosen and checked. We ask for the layout plan and the randomization record, since the analysis follows from them.
What if animals were removed during the trial?
Removed animals leave pens unequal in size but do not invalidate the analysis. Mixed models use the measurements that exist, and we examine whether the reason for removal relates to treatment, because removal for illness may itself be an outcome. Results are reported with and without those animals, and the flow of animals is documented as the guideline asks.
How is confidential trial and farm data handled?
Trial protocols, farm and herd records, field layouts and analysis files are handled confidentially, and project information is not published. An NDA is available where required and can be arranged before sensitive materials are shared. Read more about confidentiality and data security.
What happens when I request an assessment, and how long does it take?
You share your research question, design and relevant materials, and a statistically trained Research Coordinator reviews the request and responds the same day. The analysis, deliverables, timeline and one fixed project fee are then confirmed before any work begins, so the timeline follows from the agreed scope.
Still have a question? Find more answers in our full FAQ.
NEXT STEP
Discuss Your
Agricultural or Veterinary Research With Us
Share your research question, trial layout and available data, even if only a field plan or a season of records exists. We review how units were allocated and confirm the approach first.
No Commitment Required
Strictly Confidential
Fixed Project Fee
In-House PhD-Level Statisticians
Same-Day Response
Serving Researchers Since 2014