Terpenes have been proposed as potential biomarkers in verifying the diets of grazing animals. A study of the relationships between the intake of terpenes and their presence in animal tissues (blood and milk) as well as in the final product (cheese) was conducted. Eight dairy sheep were divided into two equal groups, representing control (C) and treatment group (T). In T group oral administration of a mixture of terpenes, α-pinene, limonene and β-caryophyllene, was applied over a period of 18 days. Blood and milk samples were collected regularly and terpenes were identified by extraction using petroleum ether and the solid phase micro-extraction (SPME) method, respectively, followed by GC-MS analysis. Cheese was produced, from C and T animals separately, twice during the period of terpenes oral administration. Terpenes contents and chemical properties of the produced cheeses were investigated. Limonene and α-pinene were found in all blood and milk samples of the T group after a lag-phase of 2 days, while β-caryophyllene was detected in few plasma samples and in all milk samples. None of the terpenes was traced in blood and milk of C animals. The contents of cheese, in dosed terpenes, presented a more complicated pattern suggesting terpenes non-credible as biomarkers. We conclude terpenes can be used as biomarkers for authentification of ewes' milk, but further research is required on factors affecting their transfer to dairy products from grazing diets.

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Anthelmintic resistance (AR) in sheep raised under mountain farming conditions in South Tyrol (Northern Italy) was assessed on eight farms (n=99 animals). A faecal egg count reduction (FECR) test was done after routine anthelmintic treatments. Furthermore, on 27 farms (n=306 animals), a FECR test was conducted after oral formulations of a macrocyclic lactone (ML), benzimidazole (BZ) (partly in combination with salicylanilide (SA)) or a combination of imidazothiazole and SA were applied under controlled conditions on the same farm. Following routine treatments, three of five ML-treated flocks showed an adequate efficacy, while the other two reached a FECR of only around 75 per cent. A wide range of gastrointestinal nematode genera were identified in one flock following the treatment. From the three BZ-treated flocks, only one showed an adequate FECR, both other farms reached 68 per cent and 84 per cent, respectively. Under controlled conditions, FECR ranged between 77 per cent and 81 per cent indicating AR for all the applied anthelmintics. Trichostrongylus species, Teladorsagia species and Haemonchus species were identified after ML treatment, Teladorsagia species after BZ treatment and Trichostrongylus species and Haemonchus species after combined BZ and SA application. Taking into consideration that underdosing might have affected results of the routine treatments, a high prevalence of AR was found in sheep under mountain farming conditions.

The objective of the present study was to investigate the relationships between terpenes’ intake and their presence in animal tissues (blood and milk) as well as in the final product (cheese). Eight dairy goats were divided in two balanced groups, representing control (C) and treatment (T) group. In T group oral administration of a mixture of terpenes (α-pinene, limonene and β-caryophyllene) was applied over a period of 18 d. Cheese was produced, from C and T groups separately, on three time points, twice during the period of terpenes’ oral administration and once after the end of experiment. Terpenes were identified in blood by extraction using petroleum ether and in milk and cheese by the use of solid phase micro-extraction (SPME) method, followed by GC-MS analysis. Chemical properties of the milk and the produced cheeses were analyzed and found not differing between the two groups. Limonene and α-pinene were found in all blood and milk samples of the T group after a lag-phase of 3 d, while β-caryophyllene was determined only in few milk samples. Moreover, none of the terpenes were traced in blood and milk of C animals. In cheese, terpenes’ concentrations presented a more complicated pattern implying that terpenes may not be reliable feed tracers. We concluded that monoterpenes can be regarded as potential feed tracers for authentification of goat milk, but further research is required on factors affecting their transfer.