Wanyangu, S.W.Sakwa, D.P.Kyule, M.N.Bain, R.K.Mugambi, J.M.Muthee,S.2015-08-122015-08-121966Wanyangu, S.W.,Wanyangu, S.W.,Kyule, M.N.,Bain, R.K.,Mugambi, J.M.,Muthee,S. ( 1966 ). Survival analysis techniques in the study of the development and survival of Haemonchus C0ntortus L3 larvae on pasture in Kenya. Veterinary Research, p. 85-940928-4249http://kalroerepository.kalro.org/handle/0/9319Life tables and survival analyses with covariates were used to assess the development and survival of Haemonchus contortus infective larvae 13 on pasture composed of mixed grasses. Thirty nine plots, each measuring 2 m2, were subdivided into 144 sub-plots, each measuring 10 cm.2 three randomly selected plots were every month uniformly contaminated with sheep faeces containing 2 x 106 H. contortus eggs. Every week after contamination, grass and faecal material from three randomly preselected sub-plots were collected and analysed for larval recovery. Life table analyses showed that 50% of the total L3 that developed from contaminated sheep faeces were recovered from pasture within two to eight weeks. Ninety percent recovery occurred within 6-20 weeks post-seeding. Comparisons of survival curves of from plots seeded at different times of the year revealed significant (P:::: 0.01) differences which were shown by trend tests to be seasonally related. An Accelerated Failure Time Model (AFTM) assessed the effect of the major meteorological factors (covariates) on survival of L30n pasture. Sunshine had the greatest influence on survival (=- 0.1123) followed by temperature (6 = 0.(839), relative humidity (B =-0.(29) and rainfall (B=O.0013). Sunshine and relative humidity had an adverse effect on survival whereas rainfall and temperature enhanced it. Using these techniques intervention points for strategic anthelmintic control for haemonchosis identified the end of December (beginning of the hot dry period) and July (beginning of the cold dry period) as the most suitable times to administer anthelmintic. Tactical treatments could be carried out during the rainy periods.englishhttp://creativecommons.org/licenses/by/3.0/Journal ContributionPasturesGrassesSheepRainfall