EN
Our objective was to compare the effects of a conventional antiparasitic chemical drug and a lick block containing plant-based compounds on the economic value of lambs. Ewes and their new-born offspring were allocated among three treatments: a group receiving standard drenching with an albendazole-containing drug, a group supplied with a lick block containing essential oils from 10 plant species having antiparasitic properties, and a control group that was not dewormed. During the experiment, all lambs were given periodic birth weighings at 28, 56, 70 and 100 days of age. The results obtained were the basis for the estimation of the economic value of lambs reared in particular experimental groups of the observed animals. The average price earned for slaughter material in each weight standard was used to calculate the differences between the groups. The current prices were made available by the Regional Association of Sheep and Goat Breeders in Lublin. All lambs (live at 56, 70, 100 and 120 days) were included in calculations of the average value of the animals. In the case of lambs falling within the standard 0 to 12 kg, a value for 0 PLN per kilogram was assumed because of the lack of sales potential. At 56 days, the value of the lambs in the group receiving feed with the addition of essential oils was 11.90% higher than that of the lambs from control group. At 70, 100 and 120 days, the value of those lambs was higher than that of the lambs from control group by 21.13%, 4.99% and 5.51%, respectively. The value of the lambs from the group receiving standard drenching with an albendazole-containing drug was similar to that of the lambs from the undewormed group. The results of the research indicate that it is beneficial to use natural substances in the prevention of parasitic invasion. The use of natural methods to reduce parasitic infestations will reduce the application of chemicals, which is extremely important due to the increasing resistance of parasites and the preferences of consumers, who search for products free of harmful residues of medicinal substances.