The gastro- intestinal tract (GIT) of animals contains variety of parasites primarily helminthes, which are responsible for sub clinical and clinical parasitism.Major economic losses in the livestock industry are caused by adverse effect on the health status of animals by these parasites. The effect of these parasitic infections include decreased milk production, edible offals and meat refusal, decrease of hides, late maturity and death mostly in calves and more production cost because of drugs usage. Plants are being used as anthelmintic as the allopathic drugs today which offer alternate to the use of synthetic chemicals.
Aqueous and methanol extracts of Nicotiana tabacum leaves are effective against Haemonchus placei in cattle.
A total number of one hundred (n=100) samples of cattle round worm Haemonchus placei directly brought from slaughter houses were included in this study and for the efficacy of In vitro aqueous extracts of Nicotiana tabacum leaves the abomasal contents were preserved in normal saline containing jars.
In-vitro aqueous extracts were prepared in stock solution and the different dilutions of these extracts were used to calculate the anthelmintic efficacy in three different Petri dishes having various concentrations of Nicotiana tabacum leaves aqueous extracts in the form of percentages besides the positive and negative controls receiving single dose of Levamisole and no treatment respectively.
Adult cattle were used for In-vivo trails which were conducted in dairy farms present in Lahore. Animals were conformed for the presence of gastro-intestinal parasites by qualitative and quantitative methods of faecal analysis. Total n=24 were included in the study trials and for treatment trails n=24 cow positive for endo-parasitic infections especially for H. placei weredivided in to Six groups. Four groups were given the single treatment of aqueous extract and methanol extract 1 gm/kg and 3 gm/kg respectively while fifth group received single dose of Levamisole HCl and the sixth group was negative control and received no treatment. Faecal samples from each animal were collected in the morning, starting from day 0 pre-treatment and at days 5 and 10 post-treatment and were evaluated for the presence of worm eggs by salt flotation technique. The eggs were counted by the McMaster method (Zajac et al. 2012). The EPG standard for groups treated with crude aqueous extract was 500-600 eggs per gram and the groups treated with crude methanol extract contained 700-800 EPG. The positive control contained 900-1000 EPG. The negative control contained EPG >1000.
The comparative efficacy data were analyzed by Repeated measures analysis of variance (ANOVA) by using SPSS 20.0. A probability level ˂0.05 was considered statistically significant.
During the In-vitro study the efficacy of aqueous extracts of Nicotiana tabacum at the concentrations of 25 mg/ml, 50 mg/ml and 100 mg/ml were same against adult Haemonchus placei parasites which was 100 % during In-vitro study. All the wormsexposed to levamisole 0.55 mg/ml, a standard anthelmintic agent were found dead after three hours of incubation at 37 ºC whereas, none of the worms were found dead in Phosphate buffer solution (PBS) which acted as the negative control. These findings indicatedthe anthelmintic activity of extracts of N. tabacum.
During the In-vivo study all the treatment groups showed a significant reduction (P< 0.05) in EPG at day 5 and 10 post-treatment. The maximum reduction showed by Crude Aqueous extract (CAE) at 3 gm/kg dose at day 5 and 10 post treatment were 48.88 % and 51.11 % respectively. The maximum reduction showed by Crude Methanolic extracts at the dose rate of 3 gm/kg body weight were 75.8 % and 79.03 % respectively at 5 and 10 days post treatment. The positive control treated with Levamisole HCl showed the maximum reduction of 98.68 % in eggs per gram (EPG).
The data organized from this study were helpful to know the anthelmintic efficacy of Nicotiana tabacum leaves aqueous and methanol extracts against gastro intestinal nematode H. placei in cattle and the treatment trials provided the most reliable and cost effective treatment for round worms infestation in cattle.