65. A nucleus of birds, which represents significantly less than 1% of the national broiler breeder flock, is maintained and selected to form the basis from which all future generations are produced. In order to be able to identify those birds best suited to the future requirements of the industry, primary breeding companies undertake detailed selection performance testing on these stock. They are reared to their maximum potential growth rate up to at least 6 weeks of age, at which point selection takes place; those reaching the required standard will be moved to rearing accommodation where further monitoring and selection is carried out. Those which are not selected are culled.
66. This process creates a welfare dilemma because, having been fed ad libitum, the weights achieved by the birds at about 8 weeks of age will be above those required at point-of-lay. It is therefore necessary to restrict feed intake severely during the next 2 or 3 weeks to return the bird to physical fitness. The level of restriction which is imposed may limit intake to as little as 25% of previous feed over this period and this would imply a potentially serious welfare problem.
67. We recognise that this process of detailed selection performance testing needs to be undertaken in order to ascertain bird potential and deficiencies and it is essential for the health and welfare of future generations. The management of these birds during the period from 8 weeks to point-of-lay must provide even feed distribution, effective environmental control, avoid disease and ensure they are not exposed to any other welfare challenge. Additionally, we advocate that the feed restriction of these birds, and the number subjected to this procedure, be minimised by the industry which should constantly review the processes which make them necessary. Consideration should also be given to halting the procedure earlier, for example at 35 days.
68. The primary breeding companies should identify the best means of minimising the number of elite birds subject to detailed selection performance testing. Ideally, consideration should be given to reviewing the need for the process. Also, the breeding companies should assess and minimise the stress during the period of feed restriction whilst the birds are returned to fitness before the laying period.
69. Once the selection procedures are complete, weekly recording of weight gain must be used to check that these birds achieve a steady, progressive week-on-week increase in bodyweight growth.