Deliverable D2.3 Traits related to the individual feed intake in group-housed broilers and rabbits
Objectives
Feed cost is the main production cost in poultry and rabbits, and represents 50 to 70% of the total production cost. Consequently, feed efficiency is the most important selection criterion in these species. For meat-type producing animals, feed efficiency is defined as the ratio between weight gain to feed intake during a given period. Weight gain is relatively easy to obtain at the individual scale, although it is labour intensive. On the opposite, feed intake measurements in individual animals are more difficult to obtain. In chickens, to measure feed intake, birds are housed in individual cages and the feeder has to be weighed at regular intervals. This method has several drawbacks:
- Animals are housed individually whereas they are usually reared in groups
- Animals are housed in cages whereas they are usually reared on the floor
- The measurement is available only for longer periods, usually one measurement per week or every two weeks. This provides a very limited indication of the changes in feed intake, considering that a broiler production cycle is lasting only 5 weeks.
The objective of this deliverable is to use automatic feeding stations to obtain individual data of feed intake in group-housed animals, and that are reared in conditions as close as possible to production conditions (e.g., on the floor for chickens, in collective cages for rabbits). Moreover, these feeding stations allow for the continuous collection of data of feed intake and to establish the dynamics of feed intake within a day, and all along the production cycle. These new traits have been correlated to feed efficiency to propose new traits that can be used for both nutrition and genetics studies of feed efficiency in poultry and rabbits.
Rationale
Feeding stations are developed for individual recording of feed intake in both rabbits and chickens. Animals are identified electronically using RFID tags that are detected automatically by the feeding station when animals enter the feeding station. In chickens, animals are detected and identified by an antenna placed on the front access of the feeder. As animals climb on a plateau mounted on a scale and they are weighed at each visit. Feed intake is calculated at each visit as the difference between feeder weight at the beginning and at the end of the visit. To check whether feed intake patterns were generic or specific for a given type of production, the station was tested using rapidly growing broilers and using Label Rouge chickens with a lower growth rate, and with different types of diets. Consistency of visits collected by the feeding station and true visits were assessed by video recording.
In rabbits, measurements are done in collective cages with 4 to 7 rabbits. A circular antenna is placed at the entrance of a corridor giving access to the feeder. Feed intake is calculated at each visit as the difference between feed weight in the feeder at arrival and at departure of the rabbit. Experiments to determine the ideal size of the group of rabbits, to test the reliability of the measurements, and to estimate the effect of the feeding station on growth performance of rabbits have been carried out. Feed intake, feeding behaviour, and growth traits have been compared with different numbers of rabbits per cage and between different types of feeders.