Characteristics of production system, Epidemiology and control of Pig parasites in Busia District, Kenya
A study was carried out in Busia District to characterize the pig production system, determine the prevalence and intensity of pig parasites, identify the risk factors associated with occurrence of these parasites and determine the efficacy of pawpaw products and neem oil against Oesophagostomum spp and Haematopinus suis infections in pigs. In order to achieve these objectives, socio-economic studies, slaughter slab and farm surveys and efficacy trials were carried out. For the socio-economic survey, questionnaire data on farm characteristics was collected from 182 farmers selected from the six divisions of Busia District. The mean number of pigs per farm was 3.6, mainly (1781182, 98%) for income generation. The production systems were mainly farrow to weaner (221182, 12%) and weaner to finisher (651182, 36%). The main production constraints as perceived by farmers included pig diseases (1481182,81%) and high cost or lack of feed (1481182,81%). The slaughter slab survey involved a questionnaire survey on 16 butchers and 6 slaughter-slabs in the main urban centres in the District. The average net income per annum for each butcher was Ksh 62,688 (897 USD), while the average profit per slaughtered pig was Ksh. 268 (3.8 USD). The main constraints to butchery business were conflicts with regulatory authorities (16116,100%) and lack of slaughter pigs (15/16, 94%). The study on prevalence and intensity of parasites was carried out at both slaughter slabs (37 pigs) and farms (135 farms, 306 pigs) level in Busia District. The prevalences of nematodes shed by pigs at both the slaughter slab and farm level were:Oesophagostomum spp (100% (37/37), 75% (230/306)), Strongyloides ransomi (16% (6/37), 37% (113/306)), Ascaris suum (19% (7/37), 18% (55/306)), Trichuris suis (3% (1137), 7% (211306)), Metastrongylus spp (54% (20/37), 11% (34/306)) and Physocephalus sexalatus (24% (9/37), 3% (9/306)). The gastrointestinal protozoan parasites in both the slaughtered and farm sampled pigs respectively included: coccidia spp (85% (32/37), 33% (1011306)), Balantidium coli (89% (33/37), 64% (196/306)), Tritrichomonas suis (89% (33/37), 42% (129/306)) and Entamoeba spp (100% (37/37), 87% (266/306)). The ectoparasites observed on slaughtered and farm pigs respectively were Sarcoptes scabiei (63% (21133), 64 (195/306)), Haematopinus suis (85% (28/33), 96% (294/306)), Ixodid ticks (40% (13/33), 30% (92/306)). The prevalence of cysticercosis was 4% (111284). There was a positive correlation (p<0.05) between the amount of rainfall in a given Division of sampling and prevalence of all the nematodes except S ransomi. The prevalence of nematodes was associated with age, being highest in adults (Oesophagostomum spp), growers and finishers (A. suum, T suis) and piglets (S ransomi and P. sexalatus, Metastrongylus spp). There was negative correlation between the amount of rainfall in the Division of pig origin and prevalence of coccidia, Tritrichomonas suis, and Entamoeba spp, but a positive correlation with prevalence of B. coli. The prevalence of H suis was significantly (p<0.05) associated with amount of rainfall (negative correlation), class of pigs (highest in finishers) and lack of provision of housing. The prevalence of mange was negatively associated with amount of rainfall (negative correlation) and class (highest in sows) of pigs. Lack of latrines was the only significant (p<0.05) factor associated with the prevalence of porcine cysticercosis. The efficacy trials evaluated the effectiveness of pawpaw and neem products on Oesophagostomum spp and H suis infections in pigs using in vitro and in vivo tests. Papain and papaya latex were the most effective herbal products against Oesophagostomum spp. In the in vivo tests, levamisole, pawpaw latex, neem, papain, pawpaw powder caused faecal egg count reductions of 84.6%, 57.1%, 56%,43.2%,27.1%, respectively. At in vitro level, neem oil caused 100% mortalities in concentrations above 12.5% while amitraz at concentration of 5mglml was able to kill 100% lice in 24 hours. At in vivo level, lice counts on pigs treated with neem oil and amitraz declined significantly (p<O.OOOI) up to 28 days post treatment. In conclusion, the serious production constraints reported in this study can be addressed through education of farmers/traders using affordable extension services and improvement of the pig markets. The parasites reported in pigs for the first time in Kenya included: Metastrongylus spp, G. urosulubatus, B. coli, Tt. suis, Entamoeba spp, ixodid ticks and T penetrans. The results of this study demonstrate that pawpaw and neem oil products have significant efficacy against Oesophagostomum spp and H suis. Further studies on the pawpaw and neem oil products including elucidation of the possible toxic effects on the animals, dosage formulation and effectiveness of the products in integrated control programmes for pig parasites are recommended.