Quick Guide to Animal-based Measurement Protocols


Source: proAction

The Animal-based Measurement Protocols include step-by-step instructions for the assessment of dairy cattle for the following animal-based measures:

1. Body Condition Scores

2. Injury Scores – hock, knee, and neck

3. Lameness Scores

This Quick Guide summarizes the general protocols for assessments, specifically during the pilot phase of the benchmarking period.

Please note: assessors must meet the qualification criteria set by Dairy Farmers of Canada (DFC) and the provincial association, and must have completed DFC training in animal assessments.

Protocols on farm

1. Determine the sample size: determine the number of cattle you need to assess by referring to Table 1, and following these steps:

a) Choose the herd size closest to the number of cattle in the milking herd (lactating only) (i.e. round to the nearest number).

b) Select the related sample size.

Remember: follow strict biosecurity practices. Use clean coveralls for each farm, and disinfect boots before and after each farm. In tie-stall barns, you should consider disinfecting your boots after scoring lameness, and before you score knee and neck injuries, if you will be standing in the feed alley to score these measures.

Note: cattle assessments must be done every 2 years, and within 24 months before the farm’s registration anniversary date (e.g. the due date for the proAction validation or selfdeclaration).

Table 1 – Sample size calculator

Note: sample sizes are calculated on the basis of 95% confidence level and a margin of error of 15, except for herd sizes over 1,000 cattle.

2. Select sample of cattle

a) General rules:

• Select cattle from the lactating cattle only.

• Choose animals randomly.

• Assess all of the cattle in the sample for all of the measures on the same day.

• If cattle are distributed amongst different pens, select animals proportional to the number of animals in each pen.

• Exclude cattle in the sick pens, because the farmer is already taking corrective actions to care for those animals. Before starting the assessment in a tie-stall, ask the farmer if he/she has a sick pen or if sick animals remain in their stalls. If sick animals remain in their stalls, ask the farmer which animals would be considered “sick pen” animals so that you can determine which animals can be excluded from the assessment (i.e. equivalent to an animal that would be in a sick pen in a free-stall barn). Record the number of sick animals in the sick pen or the number of animals excluded from the assessment.

b) Specific protocols for free-stalls and other loose housing barns:

• Strive for moving cattle calmly and freely.

• The recommended methods, in order of preference, are:

i. During milking or by moving the cattle through the parlour in between milkings and releasing them through the return alley. Select animals according to the last column in Table 1.

ii. After milking with cattle secured in headlocks and released. Select animals according to the last column in Table 1.

iii. Between milkings with cattle crowded in one end of the pen and released. Select animals according to the last column in table 1. This method is not preferred because it is disruptive to the group of cattle throughout the process and risks cattle rushing and slipping.

iv. Between milkings in free-stall / bedded pack barns by searching for specific animal IDs. Use a random number generator to identify the specific animal IDs to be selected.

Note: Holstein Canada may provide loose housing clients with a list of the sample cattle for assessment within 24 hours of the assessment appointment, if the farms meet specific criteria, so that farmers can sort cattle in advance.

c) Specific protocols for tie-stalls:

• Before entering the barn, decide which cow you are going to start with, so that the choice is random. For example, decide if you are going to start with the 1st, 2nd or 3rd stall on the left-hand side before walking into the barn.

• From the initial animal, walk down the line and choose animals according to the last column in Table 1.

3. Assess cattle

a) Assess the cattle in the sample size according to the protocols outlined in the Quick Guides for Body Condition Score, Injuries, Gait Scoring and Stall Lameness. All animals are scored as either ‘acceptable’ or ‘requires corrective action’ for each measure, except for Gait Scoring, which is a 3- point scoring system of ‘acceptable,’ ‘monitor’ or ‘requires corrective action.’

b) Dirty cattle: if less than 20% of the sample cattle are too dirty to score, simply select replacement animals. If 20% or more of the sample cattle are too dirty to score, you will be unable to score that parameter accurately. Score the dirty animals as R (requires corrective action) for that parameter(s) (e.g. hock/knee) that cannot be properly scored, and note that they were too dirty to score.

4. Record the results

Record the results of the assessment in the forms provided, including the summary results. For hock injuries, the measure is recorded as R if one hock is scored as R. The same applies for knee injuries.

5. Generate comparative reports

Table 2 outlines the Excellent targets for the animal-based measures, which are the ideal goals to reach. However, for the first two years of assessments, comparative reports will be generated for each measure based on population data, which will indicate to farmers how their herds score in relation to the rest of the herds assessed. Table 3 illustrates an example of the zone thresholds. The zones are:

Green zone: represents the results that the top 25% of herds has achieved. Green means good.

Yellow zone: represents the results that the middle 50% of herds has achieved. Yellow means caution, and farmers should consider corrective actions to improve.

Red zone: represents the results that the bottom 25% of herds has achieved. Red means that farmers need to write and implement a corrective action plan in consultation with their veterinarian, nutritionist and/or dairy specialist to improve their scores and move out of the red zone.

Table 2 – Targets for animal-based measures

Table 3 – Example of the zone thresholds

The first assessment for a farm is its benchmark, and farmers are encouraged to strive for continuous improvement with the Excellent targets for animal-based measures as the ultimate goal. DFC plans to reevaluate the zone thresholds after gathering enough data to provide an overview of the animal-based measures results across Canada, and expects to move towards set targets.