Longitudinal analysis of the effects of IGF1-SnaBI genotypes on the growth curve of Angus bull calves.

ROGBERG MUÑOZ A; CANTET RJC; FERNÁNDEZ ME; LIRÓN JP; PRANDO AJ; BIRCHMEIER AN; RIPOLI MV; GIOVAMBATTISTA G

LIVESTOCK SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2013 vol. 154 p. 55 - 59

1871-1413

The Insulin Growth Factor 1 (IGF1) has been proposed as a candidate gene for growthrelated traits as it plays a central role in growth and development of mammals.A relationship between serum IGF1 concentration and different growth traits in cattlehas been documented. Furthermore, the IGF1-SnaBI SNP in the gene promoter regioninfluences gene expression and IGF1 blood level. The current research was conducted toperform a genetic analysis of longitudinal data for growth curves through the evaluationof the influence of IGF1-SnaBI genotypes on the growth curve of beef cattle during highlyanabolic stages. Data were taken on 275 Angus bull calves on two consecutive years, intwo commercial cow?calf operations. Calves were weighed at birth, at weaning, and at 3to 4 times before the year of age. A random regression animal model was employed for theanalysis. Fixed effects were age of dam, herd-year, and age of calf (linear and quadraticterms nested within IGF1-SnaBI genotype). Random effects were age at measure (linearand a quadratic terms nested within animal). The analysis showed significant differences(Po0.01) in the growth curves at ages in between 66 and 291 days for the IGF1-SnaBIgenotypes. At 210 days of age, the effect of substituting a T by a C was estimated to be5.21 kg. These results suggest that the effect of IGF1-SnaBI over growth in cattle take placemostly before pubert.