Optimizing sampling strategies for sib test schemes in a broiler breeder program

In broiler breeding there is a known genotype by environment interaction for bodyweight measured in a bio-secure (BWB) or in a commercial environment (BWC), thus a sib test scheme to record and use BWC records is beneficial. This study estimated a genetic correlation of 0.59 between BWB and BWC. To optimize the sib scheme, different genotype proportions (25, 50, 75%) and sampling strategies were studied. No pedigree information was available for birds in the commercial environment unless they were genotyped. Genotyping based on phenotypes, heaviest and lightest, resulted in the highest accuracy compared to random genotyping 0.88 vs 0.80 at 25%, 0.94 vs 0.89 for 50 and 0.97 vs 0.95 at 75% genotyped. No bias was observed with random sampling, however bias was detected with sampling based on phenotypes (0.58 at 25%, 0.76 at 50 and 0.91 at 75%)