Selection and grouping of the experimental animal's Faeces from 53 indigenous growing calves of Digharkanda and Mashkanda villages of Mymensingh district were collected and examined for parasite egg counts in the laboratory of the Department of Parasitology, Bangladesh Agricultural University (BAU), Mymensingh. Most of the animals were having different parasites, but only 25 of them were selected for the experiment based on the severity of infection in terms of nematode egg counts of 300 and above. The live weight of the animals was also considered in the selection process. The age of the animals varied from 1 to 2 years and the live weight from 33-90 kg. They were randomly distributed into five groups (A, B, C, D & E), each group consisted of 5 animals.
Feeding pattern of animals The animals were allowed to graze in the fallow land /homestead for part of the day - 6 hours and also supplied with straw-based feeds (rice straw + wheat bran). There was no significant difference among the groups in terms of feeding patterns.
Preparation of bolus with leaves for oral administration Leaves of Neem (Azadirachta indica), Atis (Annona reticulata) and Pineapple (Ananas comosus) plants were collected in the morning and washed with clean water. The leaves were then freeze-dried. The freeze-dried leaves were then ground by using a grinding machine. They were mixed with an equal amount of molasses to form the bolus. The amount of powder from each plant leaves taken to make boluses was at 200 mg/kg live weight of animals (Akbar et aL, 2003). Albendazole was added to the bolus at 7.5 mg/kg live weight. Boluses were made with Neem, Atis and Pineapple leaves separately as well as a mixture in equal proportion of these three leaves and were stored (on p night) in coloured plastic pails until use.
The layout of the animal experiment Four groups of animals (A, B, C and D) were treated with the following herbal anthelmintics where the animals of group E were administered with a synthetic drug, Albendazole (Endokill®, ACI Ltd.). The treatments were allocated randomly to different groups of animals. Feeding anthelmintics to the animals The prepared boluses were fed to four different groups of calves (A, B, C and D) in the morning. Care was taken so that no wastage of the boluses occurred. Albendazole in the tablet form was bought from the market and fed to calves (group E) directly at the same time.
Collection of faeces and examination for helminth eggs Diagnosis of helminths inhabiting the digestive tract was made by the examination of faeces because the helminths of this tract produce ova which are present in the faeces. The faecal samples were examined in the laboratory of the Department of Parasitology, BAU, Mymensingh. About 10-15 g faecal samples were obtained directly from the rectum and each sample was then placed in a separate plastic bag, packed and immediately transferred to the laboratory for helminth egg counts. Samples were collected in the morning for evaluation of pre and post-treatment load for worm ova. Firstly the faecal samples were examined for the qualitative purpose by direct smear method and if the samples were positive then the quantitative determination of helminths ova was made by McMaster method as described by Rahman et aL (1996). The efficacy of different treatments was determined by a faecal egg count reduction test using the formula mentioned by Rahman et aL (1996).
Recording of live weight of animals Pre-treatment live weight of each calf of all groups was taken at the beginning of the experiment and thereafter every fortnight interval till the 60th day of the experiment. The weights were taken with the help of weighing band by applying 5 kg tension in the morning before feeding.
Statistical analysis The experimental data were analyzed using the "MSTAT" statistical programme to compute analysis of variance and treatment means for each parameter and were compared using the least significant difference (LSD) test. Data related to the growth of calves were adjusted for initial live weight. Data related to faecal egg counts were analyzed to compute the analysis of variance for Completely Randomized Design (CRD).