Urine cortisol in pigs of different MH-genotypes | Koncentracija kortizola v urinu pri prašičih različnih MH-genotipov

English. Urine cortisol concentration was evaluated in German Landrace barrows of two MH-genotypes (NN, Nn) housed in metabolic cages. Furthermore, cortisol in urine was evaluated as a substitute measure of plasma cortisol values in pigs. Three replicates were done, each including 4 animals. Altogether there were 12 animals included in the experiment. The effect of MH-genotype on urine cortisol concentration was evaluated and correlations between urine and plasma cortisol were calculated. Higher urine cortisol values in NN- in comparison to Nn-pigs indicated stronger response to stressors by stress resistant NN-genotype. The correlation between urine (12-hr urine values) and plasma (the average of 12 collections per day, taken between 8.00 a.m. and 11.00 a.m.) cortisol values was practically negligible in samples taken on the same day (r = 0.07, P = 0.71). In time-lag samples (urine taken the day after blood collection) correlation was increased (r = 0.22), but still not significant (P = 0.22). A connection between plasma and urine cortisol values was indicated, but it should be better understood before urine cortisol is used as a substitute of plasma cortisol measuring in pigs.

Slovenian. Namen raziskave je bil oceniti koncentracijo kortizola v urinu pri prašičih dveh MH-genotipov (NN, Nn). Poleg tega smo ocenili koncentracijo kortizola v urinu kot nadomestilo določanju koncentracije kortizola v plazmi pri prašičih. Prašiči so bili pasme nemška landrace, uhlevljeni v metabolne kletke. Opravljeni so bili trije poskusi (tri ponovitve), v vsakem so bili 4 kastrati. Skupno je bilo v raziskavo vključenih 12 živali. Ovrednotili smo vpliv MH-genotipa na koncentracijo kortizola v urinu in izračunali korelacije med vrednostmi kortizola v urinu (12-urne vrednosti) in plazmi (povprečje 12-ih dnevnih odvzemov, odvzetih med 8.00 in 11.00 uro). Večja koncentracija kortizola v urinu pri NN- v primerjavi z Nn-genotipom kaže na močnejši odziv na stresorje pri NN-genotipu, odpornem na stres. Korelacija med koncentracijo kortizola v plazmi in urinu je bila statistično neznačilna pri odvzemu vzorcev na isti dan (r = 0,07, p = 0,71) in višja (r = 0,22), vendar še vedno statistično neznačilna pri odvzemu urina dan po odvzemu krvi (p = 0,22). Povezava med koncentracijo kortizola v krvi in urinu je nakazana, vendar jo je potrebno bolje pojasniti pred rutinsko uporabo kortizola v urinu kot nadomestila za določanje kortizola v plazmi pri prašičih.