Analysis of hematologic and biochemical values in pigs is an important basis for biomedical research and veterinary clinical diagnosis. Reference values for specific-pathogen-free (SPF) 1-month-old Yorkshire (Y) pigs and Yorkshire-Landrace crossbred (YL) pigs are limited. The present research aimed to describe and compare the reference values for hematologic and biochemical parameters in such pigs. Blood samples were obtained from 90 Y pigs (52 males and 38 females) and 88 YL pigs (55 males and 33 females), all 1 month old and bred in an SPF environment. Among the 16 hematologic and 15 serum biochemical parameters tested, no significant differences between the Y and YL pigs were found except in the concentration of triglyceride (P < 0.05), and heterosis was not observed. Thus, the values determined in this study can be used as basic reference values for 1-month-old Y and YL pigs and will contribute to the use of SPF pigs in biomedical research.

Striped bass (Morone saxatilis) exposed to a standardized confinement stress had markedly different clinical and endocrinologic responses, compared with hybrid striped bass exposed to the same stress. Plasma cortisol concentration increased at a faster rate and appeared to reach a higher value in striped bass than in hybrid bass. Mean plasma cortisol concentration was 742 +/- 43 ng/ml in striped bass, compared with 490 37 and 531 +/- 40 ng/ml in striped bass x white perch (M americana) and striped bass x white bass (M chrysops) hybrids, respectively, after a 45-minute net confinement. Plasma cortisol concentration also remained significantly (P = 0.003) higher in striped bass for at least 48 hours after the net confinement. These hormonal differences were associated with a markedly lower survival and resistance to infection in striped bass, compared with the hybrids.