Intra- and Inter-sample Variation in Wool Cortisol Concentrations of Australian Merino Lambs Between Twice or Single Shorn Ewes

Stress in Merino sheep can cause a reduction the quantity and quality of fine wool production. Furthermore, it has been found that environmental stress during pregnancy negatively affect follicles developing fetus. This study was part larger field investigation on effects maternal shearing frequency reproductive productivity outcomes. For this study, we investigated intra- inter- sample variation cortisol levels weaner lambs. We conducted two experiments, first to determine samples taken from topknot weaned lambs, other aim any difference between treatment (single or twice shearing) absolute In experiment, collected 10 each further divided into four subsamples, leading total 40 subsamples. second 23 lambs produced by ewes (once shorn). The were then extracted analyzed using commercially available enzyme-immunoassay order concentration samples. Statistical analysis for experiment showed there no significant subsamples lamb ( p = 0.39), but statistical < 0.001), which be expected. born one treatments 0.033), with sheared having higher average [2.304 ± 0.497 ng/g (SE); n 14] than ones once shorn [1.188 0.114 (SE), 8]. confirms sampling reliable method adapted researchers hormonal studies Second, mid-pregnancy gave birth concentrations remained unshorn pregnancy. result warrants controlled if access nutrition (feed water) may impact HPA-axis