# An agroecological approach to preparation and use of a milk protein production baseline

## TL;DR

The paper introduces a new method for monitoring milk protein production in dairy farms to better understand and manage environmental and productivity outcomes.

## Contribution

A novel agroecological approach using longitudinal data and temporal baselines to assess dairy farm performance and environmental impact.

## Key findings

- A monitoring tool was developed using farm data to track milk protein production and urea concentration changes.
- Dietary interventions can improve udder development and protein secretion, reducing nitrogen excretion.
- The approach allows precise tracking of how nutrition practices affect dairy herd nitrogen excretion.

## Abstract

Commercial dairy production occurs in a complex management environment, but increasingly, the dairy manager is expected to provide detailed reporting of productivity and environmental outcomes, for which conventional research methods double-blind crossover or case:control trials are inappropriate. This paper demonstrates the development of a milk protein production monitoring tool using a temporal (baseline) control in longitudinal, census-type investigations of modulation of system performance in response to factor change. It utilises farm-derived current and historical data, and contrasts seasonal responses with those achieved on neighbouring farms in a 2 × 2 contingency table. The approach is then shown to be useful in assessing the effect of two approaches to moderating milk urea concentration. Firstly, milk urea content can be monitored as it falls due to reduced feed protein content, and this fall can be arrested when milk protein content starts to decline relative to the value expected for the herd at any lactation stage. Secondly, by providing a dietary intervention aimed at increasing the availability of metabolic energy in the last month before calving, udder development can be augmented, leading to greater protein secretion capacity, meaning greater utilisation of circulating amino acids, and thus more limited substrate for urea synthesis. Thus, the changing impact of differing nutrition practices on dairy herd nitrogen excretion to environment can be followed with daily precision. In principle this approach can provide useful insights into a wide range of practical management interventions.