Optimise your hatchery results through comparative trials
The only true way of achieving optimal hatchery results and ensuring they are integrated in the process chain is through comparative trials. It is therefore crucial that they are carried out accurately and efficiently. In this article, we listed some key elements for successful comparative trials.
By Guy Whetherly, Incubation Researcher, Hatchery Development Department
- Before structuring your trial protocols, it is imperative that the trial objectives are clearly defined. These objectives will determine the type of trial (a single or double setter trial, or a hatcher based trial) and if there is a need for extra egg selection or different incubator settings.
For example, a trial to assess the ultimate effect of setting all eggs produced (“as laid” eggs) against selecting and setting only grade A hatching eggs1 (“good” eggs) can be conducted in several ways.
- The first method is to set alternate trays of only “good” eggs and “as laid” eggs (as shown below) into the same trolley. This method is labour intensive before the setting process, but the trays are easy to transfer and the trial needs only a single setter and hatcher.
- A second method is to use two setters, each operating the same program and parameters, filled with either all “good” eggs or all “as laid” eggs. The eggs have to be transferred using the same transfer pattern to a number of hatchers. This method requires repeating to eliminate any hatcher specific effect.
Whichever method is chosen, it is important that the same transfer patterns are used for consistency.
- It is also important to ensure that all conditions for the eggs, apart from the trial parameter specifics that you are looking to test, are equal (such as source, flock age, breed, storage conditions, fumigation, pre-heating etc.).
- After hatch, most hatcheries carry out a simple breakout of the hatch debris. To get a better understanding of the trial results, a detailed breakout should be undertaken (see Petersime News 12 for more information on breakout sessions, downloadable below). From the detailed breakout analysis, any positive or negative trends can be identified and programs or settings can be changed to optimise the results.
- If the trial includes post-hatch performance, it is also important that any possible effect of the conditions in the house is eliminated. This can ideally be achieved by centrally dividing one house, rather than dividing the chicks over several houses. Final feed conversion ratios, slaughter weights, bird uniformity and mortality data should be acquired in order to give an overall assessment. Added to this, intermittent samples should be taken at days 3 and 7 and subsequently on a weekly basis in order to indicate the potential cause of any recorded difference.
The information and data collected during the trial process allow you to analyse the results to look for trends or conclusions. These trends can then be used to optimise the setter and hatcher programs or settings to give good consistent results. The trials may also reveal necessary adjustments to the environment in the house to improve the post-hatch results.
In summary, the key factors for successful comparative trials are:
- Define your trial objectives clearly before starting.
- Ensure you parameters are recorded accurately.
- Structure your trial in such a way that the effect of all variables can be accounted for in your analysis.
- Be certain your data sample rate, size and repetition are statistically relevant. If the data you have collected lack reliability, validity or relevance, no amount of statistical testing can rescue that data.
1: The “good” eggs are eggs sorted for misshaped eggs, dirty or floor eggs, and within a graded weight range to eliminate extra large or extra small eggs.