Studies On The Expression Of HSPs In Tissues Of The Stressed Cattle

Beef cattle are subjected to a variety of stresses, which can impact the efficiency of production and health of the animal at various stages of the production cycle. These stressors may involve the following: temperature extremes, nutritional deprivation, transport, weaning and vaccination, abrupt diet changes and lactic acidosis. Stress in animal production becomes a main restriction factor for the industry development. At present, the research focuses on understanding metabolic, energetic, endocrine, immune and digestive function as a result of cattle experienced particular types of stress. These have included cold, wind, heat, under-nutrition and aspects of handling and transport stress. Generally, blood levels of glucocorticoids or the ratio of glucocorticoids and adrenocoticotropin hormone (ACTH) have often been used as an index of stress but collection of samples is a sufficient stress to induce elevated glucocorticoid levels. Therefore, blood hormone, although providing useful information about how an animal is reacting to stress, do not appear to indicate either the severity of stress or situations where animal may suffer serious health problem as a result of the stress. Recent years, a group of stress proteins known as heat shock proteins (HSPs) are studied to show many stress may induce HSP besides heat stress. Stress proteins may play a role in aiding protein in repairing damaged cell protein in response to environmental stress. It is necessary to study whether the proteins are used as a potential candidate for use in the assessment of stress in cattle.A controlled environmental temperature in cold stress experiments, 12 cattle werr subdivided evenly into subgroups and assigned to one of the following: cold environment(-18 C ) and warm environmen(18C ).The cattle in cold environment were stressed for 96 h. Blood samples for Western blot were collected from each animal. After three weeks acclimation, 6 beef cattle were stressed to ship 5 h to assess stress responses. Blood samples for western blot and RT-PCR were taken via jugular puncture prior to loading for shipment and after loading. The body temperature was recorded with a thermocouple probe as well as various body surface and environmental temperatures with a hand-held, infra-redthermometer. 6 fistulated steers were used in a cross - over design experiment. The steers were fed the all roughage diet, and had their diet changed from roughage to concentrate diet. In this case, the diet was changed in three steps from all roughage diet: initially to a 30% concentrate diet for 3 days, then to a 50% concentrate diet for 3 days and finally to a 70% concentrate diet for a further 3 days. Blood samples for Western blot were collected via jugular catheters (inserted the previous day) just before feeding and every 2 h, for 6 h after feeding on day zero, day three, day six and day nine. Rumen samples for measuring pH were collected via the rumen cannula before feeding and every 3 h after feeding on day zero, day three, day six and day nine. Rumen papilla samples for Western blot and RT-PCR were taken via the rumen cannula.For all measures, the data were analyzed by SPSS. The results are as follows: the expression of HSP70 in skeletal muscles in cold stresses beef cattle was higher than that of control (PO.01). The body temperature of the transport stresses animal were 38.81 ?.16C just 1 h before loading, 39.18 + 0.42C just 0 h after shipping, 39.06?.34C just 1 h after shipping, respectively. The body temperature of the animal after shipping was higher than that, of the animal before shipping (P<0.01). The expression of HSP70 mRNA was significantly elevated between before and after shipping (P<0.05), HSC70 mRNA was not significant (P>0.05). HSP90, HSP70 and HSC70 in lymphocytes after shipping 0 h were significantly elevated (P<0.01). In diet changes experiment. The expression of HSP90 in lymphocytes for feeding 50% concentrate diet 2 h, 4 h after feeding were significantly higher (P<0.01) than that of animal for feed roughage .The expression of HSC70...