Technical note: a double L intestinal cannula for cattle

A double L-shaped intestinal cannula was developed in an attempt to overcome problems observed previously with simple T-type cannulas. The cannula was constructed from cyclopolyvinyl chloride water pipe fittings. Construction materials were fairly rigid, but by connecting the split cannula pieces with elastic castration bands the cannula had some flexibility. Placing a short cone over the exposed cannula barrel reduced mechanical damage to the intestine. The double L cannula required a much smaller incision in the intestine during surgical insertion than a T-type cannula; it also simplified replacement. Construction is described; use and performance of the cannula has been satisfactory.     

Prolongation of xylazine/ketamine induced recumbency time with temazepam in horses

Short term anaesthesia induced with xylazine and ketamine was compared to a combination of xylazine, ketamine and temazepam (a benzodiazepine) in six adult horses. Duration of recumbency was significantly prolonged when temazepam was administered with xylazine and ketamine. No significant differences in heart rate, respiratory rate, blood pressure or arterial pH, pCO2 and pO2 were seen between the xylazine and ketamine combination plus temazepam, and xylazine and ketamine combination only treated horses.     

Comparison of culture, peroxidase-antiperoxidase reaction, and serum latex agglutination methods for diagnosis of chlamydiosis in pet birds

Comparison was made among results of cloacal specimen culture, and cloacal swab specimen (cytologic) peroxidase-antiperoxidase (PAP), serum latex agglutination (LA), and tissue PAP assays for diagnosis of chlamydiosis in 144 birds. Swab specimen PAP findings correlated poorly with LA results and failed to predict the LA test result in any bird. Only 1 cloacal swab specimen was regarded as PAP-positive and was from the cloaca of a bird from which chlamydiae were isolated in culture. The sensitivity of swab specimen PAP, compared with culture results, was 33%, whereas specificity was 94%. In this study, swab specimen PAP was a less sensitive test, compared with culture, than was reported in a previous study. The sensitivity of LA in identifying birds that were cloacal culture-positive was poor; true-positive results were not detected, compared with culture results. The specificity of the LA method was 93%, compared with culture results. Results of the tissue PAP method correlated with culture results in the 3 birds for which both tests were performed.     

Feedlot performance of Brahman x Angus versus Angus steers during cold weather

Ten Angus and 10 Brahman x Angus F1 steers were used in a 184-d trial to compare feedlot performance during cold weather (-9 to 26 degrees C). Both groups of steers were exposed to the same environment for the same amount of time. All steers were fed for the same number of days regardless of frame score to avoid frame score x environment interactions. Brahman x Angus steers were 30.7 kg heavier (P less than .05) than Angus steers at the start of the trial. Differences in age (Brahman x Angus 40 d younger) for the two breed groups did not affect final live weight or carcass weight. Brahman x Angus steers consumed .2% less feed (P less than .05) as a percentage of BW than Angus steers; however, there was no difference in overall feed efficiency. Angus steers had a higher yield grade, more fat at the 12th rib (P less than .05), and graded 90% Choice; only 10% of the Brahman x Angus were graded Choice. Brahman x Angus steers were taller at the hip (P less than .05) and longer from first rib to aitch bone (P less than .05) and from thoracic vertebrae (T12/T13) to point of hock (P less than .05). Hide thickness determined at the neck, belly, and rump was found to be similar (7.7 mm) between the two groups. Sample hair weight and diameter did not differ between groups. Fiber, fat, protein, and DM digestibility coefficients were similar between groups but Brahman x Angus feces had a higher DM content.(ABSTRACT TRUNCATED AT 250 WORDS)     

Resistance of Pasteurella multocida A:3,4 to phagocytosis by turkey macrophages and heterophils

A virulent field isolate and 2 vaccine strains of Pasteurella multocida A:3,4 were compared for resistance to phagocytosis by turkey macrophages and heterophils, using in vitro assays. The least virulent vaccine strain (M-9) was phagocytosed to a greater degree than was the field isolate or the other vaccine strain (Clemson University). All 3 bacteria differed significantly from each other in the amount of capsular material present as measured by polycationic ferritin labeling and electron microscopy. Removal of the capsule with hyaluronidase resulted in a significant increase in phagocytosis of the field isolate.     

Effect of coliform bacteria, feed deprivation, and pH on ruminal D-lactic acid production by steer or continuous-culture microbial populations changed from forage to concentrates

Fecal coliform bacteria were isolated from three herbivores (cattle, horse, and red panda) and shown to produce primarily the D-form of lactate, plus acetate and ethanol when grown anaerobically in 1.0% glucose broth. To evaluate coliform contribution to D-lactate acidosis in cattle, experiments involving a forage-adapted steer (fasted or normally fed) and four 500-ml fermentors were compared during 3 d of grain overload. In both systems, coliforms and D- and L-lactic acid production were greater from fasted than from normally fed steer inoculum. With fasted inoculum, coliform counts peaked (3 x 10(7)/ml at 7 h after initial engorgement) and receded to 10(3)/ml by the time D-lactate concentration peaked, indicating that bacteria other than coliform were responsible for the delayed peaking of D- (48 h) compared with L-lactate (24 h). Increases in lactobacilli more closely mimicked D-lactate increases than did changes in coliforms. The comparisons between the steer and fermentors showed many similar shifts in end-products and groups of bacteria, more so with the experiment initiated with fasted than with normal inoculum. With normal inoculum, VFA content and moles of butyrate/100 mol of VFA were greater in vitro than in vivo; VFA content presumably was larger because of VFA absorption in vivo. In a separate experiment, cultures initiated with identical inoculum and given the same amount of feed accumulated more lactate when pH was permitted to decrease to 5.0 than when pH was maintained at 5.5 for 6.0 or above, indicating the role buffers can have in controlling acidosis during diet change to concentrates.     

Relationship between virulence and adherence of various enterotoxigenic Escherichia coli strains to isolated intestinal epithelial cells from Chinese Meishan and European large white pigs

In vitro adherence to intestinal epithelial cells by enterotoxigenic Escherichia coli strains bearing K88, K99, F41, or 987P adhesins and of their variants not bearing adhesins (K88-, K99-, or F41-) was investigated in European Large White and Chinese Meishan pigs. Possible relationship between adherence and virulence was also examined. The K88-positive (K88+) strain strongly adhered to intestinal epithelial cells from 26 of 28 Large White pigs. This strain had previously been found to be highly virulent for Large White pigs. The only surviving pig was of nonadherent phenotype, and cells from 4 dehydrated moribund pigs had strong adherence. By contrast, the same K88+ strain found previously to have little pathogenicity for Meishan pigs adhered with variable intensity to cells from 17 of 23 Meishan pigs; correlation was not evident between adherence and virulence. The K99+ F41+ strain of porcine origin and the F41+ strain generally adhered strongly to cells from 24 and 23 Meishan pigs, respectively, and to cells from 25 of 26 Large White pigs. Correlation was not found between adherence and virulence for the 2 strains. A K99+ F41+ strain of bovine origin adhered to cells from 20 of 22 Meishan and 22 of 23 Large White pigs, and a K99- F41+ variant adhered to cells from 19 of 23 Meishan and 23 of 24 Large White pigs. The adhesin-negative variants never adhered to intestinal epithelial cells. Strain 987 known not to readily produce 987P adhesin after in vitro growth never adhered to cells during the test.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of nutrition and body condition on pituitary, ovarian, and thyroid function of nonlactating beef cows

Nonpregnant Hereford cows (n = 70) were used to determine the effect of nutrient intake and body condition on reproductive and thyroid function. Body condition scores (BCS; 1 = emaciated; 9 = obese) of cows averaged 5.0 +/- .2 on July 1, and cows were fed for 4 mo either to lose weight and BCS (thin; n = 22), to maintain weight and BCS (moderate; n = 24), or to gain weight and BCS (fat; n = 24). After November 1, cows received a complete ration to maintain weight and BCS. Cows were slaughtered in December (six thin, eight moderate, and eight fat cows) or the subsequent March (16 cows per group). Before slaughter, cows were given two injections of prostaglandin F2 alpha (PGF) 11 d apart. Six days after the second PGF injection, cows were simultaneously treated with 100 micrograms of gonadotropin releasing hormone (GnRH; i.m.) and 100 micrograms of thyrotropin releasing hormone (TRH; i.v.) and serum samples were obtained. The BCS of cows at slaughter (8 d after PGF) averaged 3.4, 5.3, and 7.1 (P less than .01) and carcass energy content averaged 243, 432, and 714 Mcal (P less than .01) for thin, moderate, and fat cows, respectively. Wet ovarian (P less than .001) and corpora lutea (P less than .01) weights were heavier for fat cows. Content of LH in the pituitary gland and concentrations of thyroxine (T4) in serum after GnRH/TRH were not influenced by nutrient intake or BCS. However, thin cows had greater concentrations (P less than .05) of LH in serum after GnRH/TRH than did moderate or fat cows. We conclude that nutrient intake and body energy reserves of beef cows influenced ovarian function and LH in serum after treatment with GnRH.