Premium
The effects of the brown ear‐tick, Rhipicephalus appendiculatus, on milk production of Sanga cattle
Author(s) -
NORVAL R. A. I.,
SUTHERST R. W.,
KURKI J.,
KERR J. D.,
GIBSON J. D.
Publication year - 1997
Publication title -
medical and veterinary entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 82
eISSN - 1365-2915
pISSN - 0269-283X
DOI - 10.1111/j.1365-2915.1997.tb00305.x
Subject(s) - biology , tick , rhipicephalus , veterinary medicine , infestation , zoology , breed , milk production , tick infestation , agronomy , ecology , medicine
. Lactating Sanga cows of the Mashona breed from Zimbabwe, receiving either a low or a high level of nutritional supplement, were exposed to two levels of infestation of adults of the brown ear‐tick, Rhipicephalus appendiculatus in the highveld of Zimbabwe. The effect of the ticks on the milk yield was measured over an 11‐week period during the rainy season from January to April 1986. A technique in which calves were weighed before and after suckling was used to estimate milk yield. There were significant treatment effects of ticks (P < 0.05) on milk production but no significant differences in liveweight gain between calves from tick‐free and tick‐infested dams. The loss in milk production was poorly related to the number of female ticks that engorged, being 9 g (SEM 4) per tick. A Friesian x Hereford (Bos taurus) reference group of cattle carried 50% more ticks than the Mashona cows, illustrating a difference in resistance between the breeds. Thirteen screw‐worm (Chrysomya bezziana) strikes were recorded amongst the thirty‐two Mashona cows compared with twenty‐one amongst the ten Friesian × Hereford animals between January and the end of March.