Variation and covariation in strongyle infection in East African shorthorn zebu calves

Date

2015

Authors

Callaby, R
Hanotte, O
Conradie van Wyk, I
Kiara, H
Toye, P
Mbole-Kariuki, Mary N
Jennings, A
Thumbi, S. M
Coetzer, J. A. W
Bronsvoort, B.M. de C.

Journal Title

Journal ISSN

Volume Title

Publisher

Cambridge University Press

Abstract

Parasite burden varies widely between individuals within a population, and can covary with multiple aspects of individual phenotype. Here we investigate the sources of variation in faecal strongyle eggs counts, and its association with body weight and a suite of haematological measures, in a cohort of indigenous zebu calves in Western Kenya, using relatedness matrices reconstructed from single nucleotide polymorphism (SNP) genotypes. Strongyle egg count was heritable (h2 = 23·9%, s.e. = 11·8%) and we also found heritability of white blood cell counts (WBC) (h2= 27·6%, s.e. = 10·6%). All the traits investigated showed negative phenotypic covariances with strongyle egg count throughout the first year: high worm counts were associated with low values of WBC, red blood cell count, total serum protein and absolute eosinophil count. Furthermore, calf body weight at 1 week old was a significant predictor of strongyle EPG at 16–51 weeks, with smaller calves having a higher strongyle egg count later in life. Our results indicate a genetic basis to strongyle EPG in this population, and also reveal consistently strong negative associations between strongyle infection and other important aspects of the multivariate phenotype.

Description

Keywords

Citation

Source

Parasitology

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1017/S0031182014001498

Restricted until

2037-12-31