The influence of selected factors on wool cortisol concentration in alpacas (Vicugna pacos).

Several internal and external factors can influence animals' hormonal activity. Cortisol level in hair and wool determines chronic stress, which is connected with the long-term HPA axis effect. Wool cortisol levels in alpacas have never been determined to this time. The study aimed to assess the influence of selected factors on wool cortisol concentration in alpacas. The study included 36 alpacas. Wool samples were collected during shearing in June 2021, cut with an electric clipper from the right shoulder and the rump. Wool samples were fragmented into proximal (winter-spring regrowth) and distal (summer-fall regrowth) segments. Alpacas' Heat Stress Index (HSI) for the summer of 2020 was 139.4, and 116 for the winter of 2021. The cortisol levels in the wool samples were determined with the General Cortisol ELISA Kit assay. The most significant differences in wool cortisol concentrations were caused by two factors: the wool segment (P < 0.001; η2 = 0.889) and the region on the body (P < 0.001; η2 = 0.876). Wool cortisol level was higher in the distal segment (referring to the summer-fall season) than in the proximal one (referring to the winter-spring season). It is suggested that alpacas can feel heat stress in summer (HSI = 139.4), which could influence higher cortisol levels in the distal segment. The wool cortisol level was higher in the rump samples than the shoulder ones. Therefore, it is essential in future studies that wool samples from all tested animals should be completed from the same body region. Differences among age and sex groups were also observed. Wool cortisol level was higher in older animals, as differences between age groups were observed in samples from the rump in the distal and proximal segments (distal, the rump younger*older: P < 0.001; η2 = 0.321; proximal, the rump older*younger: P = 0.007; η2 = 0.195). Males showed higher cortisol levels than females, as a difference between sexes was observed in samples from the rump in the proximal segment (P = 0.001, η2 = 0.271). This study emphasizes that various factors may significantly influence wool cortisol levels, which can be helpful in alpacas' welfare estimation using this hormonal indicator as a noninvasive long-term stress assessment method.

Reproductive Losses and Their Causes in Alpacas-A Survey-Based Study.

The profitability of alpaca breeding depends on satisfactory reproductive results. The study aimed to analyze the frequency and causes of reproduction-related problems in alpacas, in particular miscarriages, stillbirths, preterm births, twin pregnancies, and falls of crias within 12 months after birth. This analysis was carried out with the use of questionnaires completed voluntarily by 109 alpaca owners in three regions (British Isles, Continental Europe, and North America). Cases of miscarriage and stillbirths were reported from 44% and 36% of the farms, respectively. In half of the farms, the cases of falls of crias and young alpacas within 12 months after birth were reported. Preterm births were reported from almost half of the farms. A large number of alpaca owners did not identify the cause of fetal death. An important element increasing the cria survival rate of is the birth weight (the higher cria birth weight, the lower risk of perinatal complications and less necessity of bottle feeding). Crias from dams receiving mineral supplements had higher birth weight. This study indicated a relationship between fetal death and the occurrence of infectious diseases and scabies infestation in the herd. They may be potential causes of reproduction-related problems that are not discerned in time.