• Determine if the flocks had any problems in the field such as poor liveability, disease, feed / water issues or wet litter. This could provide valuable information if issues are seen during the trial.
• Never use sick or injured birds for processing. • Deplete and process trial houses on the same days. • Have the same feed withdrawal time for trial broilers. • Ensure that the processing plant will be able to process the entire trial within a shift.
Measurements during grow-out During grow-out it is recommended to weigh a sample of birds at selected intervals to determine weight-to-age com- parisons of the treatments and to alert to potential issues within the trial flocks. Weighing intervals will depend on the trial protocol and final processing age, but weights should al- ways be taken at days 0 and 7. Subsequently, weights can be sampled on the usual ages for the operation, either weekly or on feed change days. The more weighing’s conducted and the greater the sample of birds weighed, the more accurate
the predictions of live weight and uniformity (CV%) will be. Correctly measuring FCR will provide information on flock cost and/or profit. To determine FCR, it is necessary to have an accurately measured quantity of feed consumed by the birds, and to ensure the amount of feed delivered into each house is measured precisely. For this reason, each of the paired houses must have its own feed bin and the amount of feed delivered to that bin weighed exactly- not estimated. If the feeding equipment is not able to accurately measure the amount of feed moved from the feed bin into the feeders, it will only be possible to determine FCR over the entire growing period. Thinning is not recommended for trial flocks. The broilers must be grown to either the thin age or the grow-out age only, because thinning significantly affects FCR. If flocks must be thinned, the percentage of birds thinned must be the same in each house on trial and they must be thinned at the same age. To be able to compare flocks, mortality re- cords should be kept daily, beginning at placement, and be recorded separately by house and sex. Euthanised broilers
▶ POULTRY WORLD | No. 4, 2019
Birds should be sampled from at least three even- ly distributed lo- cations through- out each house, with sample points away from doors and walls.
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