Are rainy season environmental stresses responsible for higher mortality in pashmina goats?

Summary A study was conducted to analyse the causes of death during the period January 1985 to December 1989, in pashmina kids and goats thought to be acclimatised to a medium altitude climate. In general, mortality was higher during the rainy season (up to 62 percent) than in the winter (17 percent) and summer seasons (21 percent). An exception was the year 1987 when mortality was lowest in the rainy season, presumably due to the effects of a drought. During the rainy season the majority of 6–12 month-old kids became dull, off-feed, weak, emaciated and anaemic. Occasionally these animals showed nasal discharge and diarrhoea. Haematological examination of randomly selected animals during rainy, post-rainy and early-winter seasons in 1985, 1986 and 1989 showed very low red blood cell counts (RBC), haemoglobin (Hb) and packed cell volume (PCV); with elevated erythrocytic sedimentation rates (ESR), neutrophilia, relative lymphopaenia, eosinopaenia, hypoproteinaemia, hypoalbuminaemia, hypogamaglobinaemia, increased A:G ratio and hypoglycemia. Red blood cells showed piokilocytosis, anisocytosis, punched out or ring shapes, presence of erythroblasts, basophilic stippling and Anaplasma marginale.Post-mortem examination revealed lesions of parasites either singly or in combination. These included lice, coccidia, Moniezia expansa, Haemonchus contortus,and Trichuris ovis.Poor or slightly improved health state, anaemic blood picture and moderated mortality were witnessed 45 days post-treatment or during the post-rainy season. Early-winter studies indicated that the goats were in an excellent health condition with normal blood picture and negligible mortality. It was concluded that the higher mortality in pashmina goats during the rainy season was association with high rainfall, humidity, partial or zero grazing, confinement of goats in sheds (all environmental stresses) and parasitism. This was supported in 1987, when the lowest mortality occurred during the rainy season due to the effect of drought and the absence of environmental stresses.Dr R. Somvanshi is a veterinary pathologist and is in charge of the Clinical Pathology and Medicine Section of Livestock Production Research. Dr J.C. Biswas works in the Animal Genetics and Breeding Laboratory. Dr B. Sharma is a biochemist in the Division of virology and currently a post-doctoral fellow at the Department of Virology at the Karolinska Institute, Stockholm, S-10521, Sweden. Dr G.L. Koul works in the Animal Genetics and Breeding Laboratory as Principal Scientist. All are based at the Indian Veterinary Research Institute.