@article {45975,
	title = {Infestation with the sheep body louse (Bovicola ovis) in Merino lines divergently selected for maternal multiple rearing ability},
	journal = {Journal of the South African Veterinary Association},
	volume = {74},
	year = {2003},
	month = {2003},
	pages = {57 - 59},
	address = {South Africa},
	abstract = {Data were obtained from a population consisting of 160 Merino ewes, as well as 64 male and 75 female progeny of these ewes at the 2-tooth age. The age and sex groups were maintained in separate flocks. The population has been divergently selected from the same base since 1986, either for (high or H line) or against (low or L line) maternal multiple rearing ability. All animals were inspected for sheep lice (Bovicola ovis) during September/October 2002 after a wool growth period of at least 4 months. When expressed relative to mean L-line performance, the advantage in lambs weaned per ewe during the lambing season amounted to approximately 110\% in the H line (1.01 vs 0.48; P < 0.01). The proportion of animals on which 1 or more lice were observed were markedly lower in 2-tooth replacement ewes than in replacement rams and mature breeding ewes (0.053 vs 0.625 and 0.531, respectively; P < 0.01). One or more lice were observed on a lower proportion of H-line ewes than on those of the L line (0.413 vs 0.571, respectively; P < 0.10), while a similar tendency was observed in 2-tooth ewe hoggets (0.033 vs 0.143, respectively; P = 0.16). When the mean number of lice on individuals on which 1 or more lice were observed was compared between lines, the average number of lice observed on H-line young rams was lower than in the L line (4.36 +/- 0.85 vs 9.71 +/- 1.84 lice, respectively; P < 0.01). A similar tendency was observed in mature breeding ewes (2.15 +/- 0.38 vs 3.22 +/- 0.42 lice, respectively; P < 0.20). The more highly reproductive H-line ewes were not more susceptible to infestation with B. ovis than ewes of the L line. In fact, available evidence suggest that H-line animals could be more tolerant of B. ovis than those of the L line.},
	keywords = {animals, breeding, genetic, Lice Infestations/epidemiology/genetics/veterinary, Mallophaga, Research Support, Non-U.S. Gov{\textquoteright}t, Selection (Genetics), Sheep Diseases/genetics/parasitology, Sheep/genetics, wool},
	isbn = {1019-9128},
	author = {Cloete,S. W. and Laubscher,J. M. and Cloete,J. J.}
}
