This study was conducted to identify and determined the prevalence of trematode parasites affecting dairy cattle, establish baseline information on milk production and correlate the prevalence of trematode parasites with milk performance parameters of dairy cattle in Cagayan Valley. The study was undertaken in four provinces namely: Nueva Vizcaya, Quirino, Isabela and Cagayan province. Fecal samples were collected from 256 dairy cattle and subjected to sedimentation and Baermann technique for trematode egg and larva identification. Fasciola spp. and Paramphistomum spp eggs were identified through sedimentation whereas no larva was found using the Baermann technique. Fecalysis shows a low prevalence of trematode parasites (14.45%) detected in Cagayan Valley Low milk yield production was also noted in dairy cattle where Isabela province contribute the most. Analysis using SPSS-Pearson correlation revealed that certain variables such as Body Condition Score ( p < 0.012 , r = - 0.157 ), status of the animal ( p < 0.014 , r = - 0.153 ) average litter of milk yield per day ( p < 0 , r=-0.266) and age ( p < 0 , r = - 0.25 ) are negatively correlated with increased infection of Fasciola spp. Negative correlations were found between Paramphistomum spp. and status of the animal ( p < 0.036 r = - 0.131 ) and average litter of milk yield per day ( p < 0.028 , r = - 0.137 ).

Farmers are recommended to attend on dairy production and management trainings and should also consider the possibility of selection and crossbreeding where it is feasible with improved feeding and proper management systems to help increase milk yield production.

Thesis (Doctor of Veterinary Medicine)

includes appendices and bibliographical references.