An obstructive upper respiratory emergency in a pregnant Belgian blue heifer

In this case report, the surgical intervention and aftercare are described of an upper airway obstruction in a two-and-a-half year old, seven-months pregnant Belgian blue heifer. The animal had been referred to the Clinic for Ruminants (University of Liège) for complaints of stridor and dyspnea and suffered from necrotic laryngitis, complicated by the formation of an obstructive granuloma. Emergency tracheotomy was performed to save the life of the cow and its calf. Through the use of a self-retaining cannula, the modified tracheotomy site could be kept patent until the calf was born and the pathology resolved two months after admission. Healing of the larynx was checked and documented by use of nasal and retro-tracheal endoscopy.

Ancestral haplotype-based association mapping with generalized linear mixed models accounting for stratification

MOTIVATION

In many situations, genome-wide association studies are performed in populations presenting stratification. Mixed models including a kinship matrix accounting for genetic relatedness among individuals have been shown to correct for population and/or family structure. Here we extend this methodology to generalized linear mixed models which properly model data under various distributions. In addition we perform association with ancestral haplotypes inferred using a hidden Markov model.

RESULTS

The method was shown to properly account for stratification under various simulated scenari presenting population and/or family structure. Use of ancestral haplotypes resulted in higher power than SNPs on simulated datasets. Application to real data demonstrates the usefulness of the developed model. Full analysis of a dataset with 4600 individuals and 500 000 SNPs was performed in 2 h 36 min and required 2.28 Gb of RAM.

AVAILABILITY

The software GLASCOW can be freely downloaded from www.giga.ulg.ac.be/jcms/prod_381171/software.

CONTACT

francois.guillaume@jouy.inra.fr

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.