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peer reviewed | Growth-related changes in pulmonary function values (PFV) of cattle were investigated by a cross-sectional study of 40 healthy Dutch Friesian cattle, 3 days to 13 years of age and weighing 37 to 660 kg. Technical and methodologic procedures and body conformation and condition were standardized. A regression analysis was done with 4 independent variables (body weight, thoracic perimeter, body surface area, and age) and with PFV measured in this study. Ventilation values, dynamic lung compliance, and viscous work of breathing changed linearly with somatic growth. Respiratory frequency, total pulmonary resistance, and arterial oxygen tension showed an exponential relationship with all the independent variables. On the other hand, intrapleural pressure values were weakly correlated with body size indexes. The most important growth-related changes in PFV occurred at approximately 1 year of age. A significant (P less than or equal to 0.05) difference between immature and mature cattle was shown for the blood-gas values and the specific values of the breathing mechanics. The dynamic lung compliance/lung weight was lower and the total pulmonary resistance X minute volume was higher in cattle than in other domestic mammals. The regression equation, giving the best fit of the data, was selected for each PFV.

peer reviewed | Measurements of airflow (V), tidal volume (Vt), and intrapleural pressure (Ppl) were tested for accuracy in 5 healthy Dutch Friesian calves with an average body weight of 153 kg. A face mask was constructed, using fiberglass and polyester, taking into account the typical facial morphology of the calf. It was tested for airtightness, dead space, laminarity of the expiratory V, and absence of saliva into the pneumotachograph. Three different systems for measuring Ppl (pleura puncturing, esophageal balloon catheter, and esophageal saline solution-filled catheter) were tested in vitro, in a Woulfe's flask, and in vivo, in the 5 calves previously described. Moreover, Ppl measured at 3 different puncture sites of the thorax and at 3 different thoracic positions of the esophagus were compared. The frequency-response was flat to 5 Hz for the intrapleural needle and the balloon catheter, but not for the saline solution-filled catheter. The pulmonary function values obtained by puncture of the pleura at the right 9th intercostal space on a line running from the tuber coxae to the shoulder joint and by the esophageal balloon catheter, the balloon being positioned between the crossing point with the aorta and the 2 largest caudal mediastinal lymph nodes, did not differ significantly. The Ppl changes during normal breathing were greatest in the ventral site of the thorax and in the caudal thoracic portion of the esophagus, less in the dorsal site of the thorax and the middle thoracic portion of the esophagus, and least in the cranial site of the thorax and the cranial thoracic portion of the esophagus. When the balloon was positioned between the crossing point with the aorta and the 2 largest caudal mesiastinal lymph nodes, Ppl recordings showed a twice smaller variability than with the 2 other esophageal positions.

Ostertagia ostertagi, calves (nat. and exper.), type I ostertagiasis, assay of lymphocyte reactivity to O. ostertagi L3 antigen and phytohemagglutinin, possible lack of genus specificity to antigen shown by reaction using lymphocytes from Cooperia punctata-infected calves, kinetics of lymphocyte reactivity showed transient nonspecific suppression of cell-mediated immune responses during prepatent periods of type I ostertagiasis, immunosuppression phenomenon may have role in O. ostertagi pathogenesis and development of immunity

Boophilus microplus, B. annulatus, Hereford heifers (exper.), permethrin or fenvalerate applied as sprays, both pyrethroids could provide adequate reduction in control programs however both acaricides failed to provide the necessary reduction to achieve complete elimination

Trichinella spiralis, day-old chicks (exper.), most worms expelled, some matured in intestine and produced larvae which penetrated muscles, little or no development there, followed by death and degeneration, viability of larvae from chickens confirmed by mouse infection

acute Sarcocystis cruzi infection in calves (exper.), hematologic studies support claim that anemia is an extravascular hemolytic event, probably with immunologic basis; coagulation studies indicate that endothelial S. cruzi schizonts may cause endothelial damage, resulting in coagulation abnormalities that include disseminated intravascular coagulation

tick infestations did not cause suppressed immune responses to Anaplasma marginale vaccination in calves, anaplasmosis did not prevent calves from developing resistance to tick reinfestation which was accompanied by immediate hypersensitivity reactions against homologous tick extracts, Dermacentor albipictus did not seem to share common antigenic determinants with Boophilus microplus

helminths of naturally infected dogs and cats, effect of febantel/praziquantel paste

Ostertagia ostertagi, beef calves (exper.), levamisole gel formulation evaluated for efficacy, safety, and residues