Serum hormone and metabolite concentrations in fasted young bulls and steers.

The effect of dietary energy restriction on serum insulin, insulin-like growth factor I (IGF-I), growth hormone, (GH), cortisol, plasma urea nitrogen (PUN) and nonesterified fatty acid (NEFA) concentrations was examined. Angus bulls and steers (10 mo) were allotted to two groups of 12 animals and assigned a treatment order. In a switchback design, animals in order 1 were fed a high grain diet, then fasted, while order 2 animals were fasted, and then fed. Animals were allowed 60 hr to acclimate between treatments. Serum and plasma were obtained at 20 min intervals and 60 min, respectively, for 6 hr after feeding and for the last 6 hr of a 30 hr fast. Serum was assayed for insulin, IGF-I, GH, and cortisol (total and free). Plasma was assayed for PUN and NEFA. Mean insulin (ng/ml) differed between fed (.95 +/- .08) and fasted (.26 +/- .08) animals (P less than 01). Both mean total and free cortisol (ng/ml) were lower in fed (11.48 +/- .99) (1.06 +/- .12) than in fasted (17.10 +/- .93) (1.62 +/- .12) animals, respectively (P less than .01). Animals in order 1 differed in mean IGF-I (ng/ml) between fed (199.0 +/- 8.0) and fasted (116.5 +/- 7.2) treatments (P less than .01). Mean IGF-I for animals in order 2 was 146.7 +/- 7.2 in fed and 213.9 +/- 7.2 in fasted animals (P less than .01). Mean GH did not differ between treatments. Mean PUN and NEFA were higher in fasted than in fed animals (P less than .01). Except for % free cortisol (P less than .05), the hormones did not differ between bulls and steers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Avian leucocyte common antigens: molecular weight determination and flow cytometric analysis using new monoclonal antibodies.

New leucocyte common antigens expressed on all the normal chicken leucocytes have been characterized using two monoclonal antibodies designated as K-11 and K-55. These monoclonal antibodies stained virtually 100% of the leucocytes derived from various lymphoid organs including the spleen, thymus, bursa of Fabricius, caecal tonsil and peripheral blood, as well as a monocytic cell line (MC29), a B cell line (LSCC-RP9), and a T cell line (CU12). However, they did not stain mature erythrocytes, intestinal epithelial cells, or chicken embryonic fibroblasts. The two monoclonal antibodies showed different staining patterns and detected non-overlapping epitopes on MC29 cells in two color immunofluorescence analysis. Western blot analysis under non-reducing conditions showed that the monoclonal antibody K-11 recognized three splenic leucocyte proteins with molecular weights of 92, 42 and 41 kDa, whereas the monoclonal antibody K-55 recognized two proteins with molecular weights of 97 and 42 kDa. The data indicate that the monoclonal antibodies K-11 and K-55 recognize novel leucocyte-common antigens which have lower molecular weights than the previously reported leucocyte-common antigen family.     

Frictional properties of cattle hooves and their conformation after trimming

The conformation of the hooves of nine heifers obtained from an abattoir was measured and their coefficient of static friction (mu) was determined for movement in forward, backward and sideways directions. The hooves were trimmed by the Dutch method and their conformation and p were measured again. Trimming increased mu, and decreased the length of the digit and the angle between it and the floor. The value of mu was considerably greater for movement in a forward or backwards direction than sideways. The relationship between the value of mu for sideways movement and hoof conformation was examined by using 52 lower limbs from a variety of cattle breeds. Although mu was greater for Belgian blue than other cattle breeds, there were no relationships between mu and hoof conformation, including a measure of the roughness of the sole.     

Survival and Growth of White Bass Morone chrysops Reared at Different Salinities

Abstract.— Juvenile white bass Morone chrysops (age 158 d, 110.4 mm total length) were reared at salinity levels of 0, 4, 8, 12, 16, and 20 parts per thousand (ppt). Fish (10/tank) were stocked in 64-L tanks with four replicates/treatment ( N = 40heatment) and fed a pelleted feed daily. Fish were sampled semimonthly for 70 d. Fish reared at salinities of 12 ppt and below were significantly ( P ≤ 0.05) larger (mean = 151.5 mm total length; range 146.8–155.7 mm) than fish reared at salinities of 16 and 20 ppt (mean 133.7 mm total length; range 131.5–135.8 mm) after 70 d. Survival was also higher ( P ≤ 0.05) among fish reared at salinities of 12 ppt or lower (mean 85.6%; range 77.5%–92.5%) compared to those reared at the two highest salinities (42.5% survival at 16 ppt; 5.0% survival at 20 ppt). Thus, although typically found in freshwater habitats, white bass can survive and grow in brackish water.     

Transfer of drugs across the ruminal wall in goats.

The rates at which pentobarbital, salicylate, antipyrine, and quinine were transferred from the rumen of intact, conscious goats were measured. The rates at which the same drugs diffused from the blood plasma (under conditions of constant drug concentration) into the ruminal solution were also evaluated. These compounds were absorbed by simple diffusion, and the rates of transfer were a function of pH of the intraruminal solution. The diffusion of drugs from plasma into the reticulorumen allowed steady-state distributions to be established in some goats. The theoretical and observed steady-state distributions were compared. There were good correlations for pentobarbital and antipyrine, but not for salicylate and quinine. These findings confirm in vivo the general principles of drug transfer across ruminal epithelium that were derived from previous studies conducted in vitro.