The aim of this study was to evaluate the trend of adrenocorticotrophic hormone (ACTH) and cortisol levels in mares during peripartum period. Twelve pregnant mares (Group A) were weekly monitored from the last 6 weeks before foaling (6BF-1BF) until the first 3 weeks after foaling (1AF-3AF). Twelve non-pregnant non-lactating mares constituted the control (Group B). Jugular blood samples were analyzed for plasma ACTH and serum cortisol concentration. ACTH showed higher values (P<0.05) at 1BF compared to the postpartum data points (1AF, 2AF and 3AF) in Group A. Cortisol levels were higher (P<0.05) at 1BF and 2BF compared to the 3AF in Group A. A significant positive correlation between ACTH and cortisol values was found in mares from Group A throughout the peripartum period (Pearson’s r=0.40; P=0.0028). The Dunnet’s test showed lower ACTH values in Group A at postpartum data points than control, and higher cortisol levels in Group A throughout prepartum times and at 1AF than control (P<0.0001). The decrease of ACTH and cortisol levels found during the early postpartum period could indicate a reduced HPA response to physical and/or psychological stress during this physiological phase. This could help the mare to protect against stress-associated inhibition of lactation, relieve psychological stress, and enhance her immune function. Further studies involving the evaluation of prolactin and sex steroid hormones values are needed to fully understand the dynamic hormonal changes occurring in pregnant and lactating mares in order to permit clinicians to make appropriate interpretation of the results.
Preliminary study on the relation between polar vixens’ temperament type and the values of selected physiological indicators and cortisol level in the blood serum The aim of this study was to examine whether there is a correlation between temperament type of polar foxes females, determined with the behavioral tests, and the level of selected physiological indicators and the level of cortisol in blood serum. In the result of conducted studies, there were no differences found between the number of breaths or the number of heartbeats in animals of different temperament types. It was found a higher body temperature in vixens with aggressive temperament compared with the vixens of trustful temperament. The difference was statistically significant (p<0.05). The level of cortisol in the blood serum of aggressive and fearful foxes was higher compared with trustful animals. The observed trend was statistically confirmed (p<0.01). In conclusion it can be said that the study of body temperature and the cortisol level in a blood serum of vixens can be a complementary method to evaluate its suitability as a breeding animals. Full verification of observed dependencies requires confirmation from greater material.
4
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Levels of Cortisol in blood serum of 50- and 100-day-old rams of Kamieniecka sheep (K) and its crossbreds (F,) with Berrichon du Cher (KxBCH) and Blackhead (K x B) rams before pre-slaughter handling and after slaughter were determined. No relationship between the Cortisol levels and the genotype of the animals were found. However, age-dependent differences in the concentrations of the hormone (P ≤ 0.01) were disclosed. In the group of 50-day-old rams, the level of Cortisol was 48.69 nmol/1 whereas in older animals it was 61.53 nmol/1. After handling and slaughter a significant increase in the hormone levels from 39.51 to 70.72 nmol/1 was found, presumably reflecting a pronounced stress response of the animal organisms.
The experimental materials comprised 44 hybrid [ (♀Polish Large White x Polish Landrace) x ♂Duroc] growing-finishing pigs. The animals were randomly divided into two groups: 24 pigs were slaughtered immediately after transport and 20 pigs were slaughtered after a 24-hour rest period in the lairage. The meat content of pork carcasses, carcass dressing percentage, the proximate chemical composition, physicochemical and sensory properties of meat and shear force values were determined. Serum creatine kinase activity and cortisol levels were determined in blood samples collected before transport and during carcass bleeding. Pigs slaughtered immediately after transport, compared with those slaughtered after a 24-hour rest period, were characterized by a higher meat content of the carcass and a higher carcass dressing percentage. Pre-slaughter handling had no effect on pork quality. The incidence of normal-quality meat, partially PSE (pale, soft, exudative) meat and PSE meat was similar in both groups. Chemical analysis showed that the content of dry matter, total protein, fat and minerals in meat was comparable in both groups. As regards the functional properties of the pork, samples from the carcasses of pigs that had rested before slaughter had a higher contribution of the red color component. Meat from pigs slaughtered immediately after transport had more desirable sensory properties. Pre-slaughter resting had a significant effect on those analyzed physiological parameters which were found to be good indicators of pre-slaughter stress. Serum creatine kinase activity and cortisol levels were higher in blood samples collected after transport (during carcass bleeding) than in samples collected before transport, pointing to a strong stress response of animals to pre-slaughter treatment. The decrease in serum cortisol levels in blood samples collected during bleeding from the carcasses of pigs slaughtered after a 24-hour rest period, compared with samples collected from animals slaughtered immediately after transport, suggests that rest before slaughter alleviated stress induced by pre-slaughter handling operations.