Summary

Feather-sexing of meat chicken breeds in Australia is not possible anymore due to the change of genetics that slow feathering female is no longer used for breeding broilers. Therefore, researchers in poultry nutrition area are facing difficulty to perform studies in a powerful manner. Other sexing methods are available and in ovo sexing technologies are under development. However, whether these sexing approaches are practical for research purpose has not been assessed. Furthermore, whether performing research experiments with single sex (i.e., male only), same sex- ratio (1:1) among the treatments, or with randomly distributed sex in the treatment aided by using sex as co-variate are powerful enough for research purpose has not been fully understood in poultry.

Program

Chicken Meat

Research Organisation

University of New England

Objective Summary

The assessment of sexing options for nutritional research
As the birds are not feather sexable anymore as has been stated in the previous sections, the ways to obtain single sex birds will be explored and compared for availability, feasibility and cost effectiveness.
The approaches include the following steps to assess likelihood to sex birds in hatcheries or on the arrival of research facility using the commonly used methods, and statistical power of experimental design using sex separated chickens or equally mixed-sex chicken:
1. Assess the availability and costs of vent sexing in hatcheries to obtain male-only day old birds for the research groups at University of New England, The University of Sydney, The University of Queensland, and South Australia Research and Development Institute (SARDI). We will communicate with the hatcheries and poultry sexers in surveying: a. likelihood of the hatcheries to allow sexers to access the hatcheries to vent sex birds; b. the availability and costs for sexers to vent sex birds at hatcheries at research scale.
2. Statistical power of experimental design using sex separated chickens or equally mixed-sex chicken – growth response of birds to low protein diet compared to normal protein diet
Experiment 1. The experiment will be performed to employ a 2 × 2 factorial arrangement of treatments with rearing (separate or mixed) and protein level (for example, normal – 21%, and low – 19% at grower phase) as factors. The birds will be sexed at day 0 (vent sexing) or d7 (DNA sexing) after the arrival of day old chicks at the research facility. The birds will then be allocated to floor pens for performance measurements. The birds will be fed with starter, grower and finisher, and treatments of different protein levels will be applied.