Accuracy of genomic selection for reducing susceptibility to pendulous crop in turkey (Meleagris gallopavo)

E A Abdalla; B O Makanjuola; N van Staaveren; B J Wood; C F Baes

doi:10.1016/j.psj.2021.101601

Accuracy of genomic selection for reducing susceptibility to pendulous crop in turkey (Meleagris gallopavo)

Poult Sci. 2022 Feb;101(2):101601. doi: 10.1016/j.psj.2021.101601. Epub 2021 Nov 20.

Authors

E A Abdalla¹, B O Makanjuola², N van Staaveren³, B J Wood⁴, C F Baes⁵

Affiliations

¹ Centre for Genetic Improvement of Livestock, University of Guelph, Guelph, Ontario, Canada, N1G 2W1. Electronic address: eabdalla@uoguelph.ca.
² Centre for Genetic Improvement of Livestock, University of Guelph, Guelph, Ontario, Canada, N1G 2W1.
³ The Campbell Centre for the Study of Animal Welfare, Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1.
⁴ School of Veterinary Science, University of Queensland, Gatton Campus, Queensland, Australia, QLD 4000; Hybrid Turkeys, Kitchener, Canada.
⁵ Centre for Genetic Improvement of Livestock, University of Guelph, Guelph, Ontario, Canada, N1G 2W1; Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland.

Abstract

Pendulous crop (PC) in the turkey occurs when the crop distends from its normal position, thereby preventing the movement of feed and water from the crop down into the digestive system. This condition negatively impacts the turkey industry at both production and welfare levels. In this study, we estimated the genetic parameters for PC incidence and its genetic correlation with 5 production traits. Additionally, we evaluated the prediction accuracy and bias of breeding values for the selection candidates using pedigree (BLUP) or pedigree-genomic (ssGBLUP) relationships among the animals. A total of 245,783 turkey records were made available by Hybrid Turkeys, Kitchener, Canada. Of these, 6,545 were affected with PC. In addition, the data included 9,634 records for breast meat yield (BMY); 5,592 records for feed conversion ratio (FCR) and residual feed intake (RFI) in males; 170,844 records for body weight (BW) and walking score (WS) between 18 and 20 wk of age for males (71,012) and females (99,832), respectively. Among this population, 36,830 were genotyped using a 65K SNP Illumina Inc. chip. While all animals passed the quality control criteria, only 53,455 SNP markers were retained for subsequent analysis. Heritability for PC was estimated at 0.16 ± 0.00 and 0.17 ± 0.00 using BLUP and ssGBLUP, respectively. The incidence of PC was not genetically correlated with WS or FCR. Low unfavourable genetic correlations with BW (0.12 and 0.14), BMY (0.24 and 0.24) and RFI (-0.33 and -0.28) were obtained using BLUP and ssGBLUP, respectively. Using ssGBLUP showed higher prediction accuracy (0.51) for the breeding values for the selection candidates than the pedigree-based model (0.35). Whereas the bias of the prediction was slightly reduced with ssGBLUP (0.33 ± 0.05) than BLUP (0.30 ± 0.08), both models showed a regression coefficient lower than one, indicating inflation in the predictions. The results of this study suggest that PC is a heritable trait and selection for lower PC incidence rates is feasible. Although further investigation is necessary, selection for BW, BMY, and RFI may increase PC incidence. Incorporating genomic information would lead to higher accuracy in predicting the genetic merit for selection candidates.

Keywords: genetic correlation; pendulous crop; prediction accuracy; prediction bias; single-step.

MeSH terms

Animals
Body Weight
Chickens
Female
Genomics
Genotype
Male
Models, Genetic*
Pedigree
Phenotype
Turkeys* / genetics