Eight Holstein cows, 4 inoculated intracisternally in 1 quarter of the mammary gland with Escherichia coli and 4 noninfected controls, were administered ceftiofur sodium (3 mg/kg of body weight, IV, q 12 hours) for 24 hours, beginning at 14 hours after inoculation of infected cows. All challenge-exposed cows became infected, with mean +/-SEM peak log10 bacterial concentration in milk of 5.03 +/-0.69 colony-forming units/ml. The infection resulted in systemic signs (mean peak rectal temperature, 41.5 +/- 0.3 C; anorexia; signs of depression) and local inflammation (mean peak albumin concentration in milk, 7.89 +/- 1.71 mg/ml). Ceftiofur was detectable in milk from all challenge-exposed cows, compared with only 1 of 4 noninfected cows, and the mean period after inoculation that ceftiofur was detectable in milk was longer (P < 0.05) in infected (147.7 +/- 27.5 hours) than noninfected cows (1.3 +/- 1.3 hours). However, maximal ceftiofur concentration attained in milk for all cows was 0.28 micrograms/ml, and was 0.20 micrograms/ml or less for all but 2 milk samples collected for 10 days after challenge exposure. Mean serum concentration of ceftiofur peaked at 1.0 +/- 0.3 micrograms/ml and 0.7 +/- 0.1 micrograms/ml for infected and noninfected COWS, respectively. After each ceftiofur dose, mean peak and trough concentrations of ceftiofur in serum did not differ between groups; however, concentration of ceftiofur in serum was higher at 7 hours after each dose in noninfected cows, suggesting more rapid clearance of the drug in infected cows. Ceftiofur was not detected in serum (< 0.05 micrograms/ml) of any cow at or after 120 hours following inoculation of infected cows Storage of serum samples at -20 C for 3 weeks resulted in a 98.8% decrease in ceftiofur activity, compared with that in fresh serum samples. Eighty-seven percent of this loss occurred 30 minutes after mixing serum and ceftiofur; thus, about 13% of the original activity was lost in storage.

Effects of temperature and storage time on canine bone-transfixation pin specimens were tested by comparing pin pull-out forces. A total of 16 femurs from 8 mature dogs were tested. Five nonthreaded Steinmann pins were placed through both cortices in the diaphysis of each femur. The femurs were then sectioned transversely between each pin, with a bonepin specimen placed evenly into each of 5 groups prior to biomechanical testing. Four bone-pin specimen groups were stored at -20 or -70 C for 14 or 28 days, while 1 specimen group was immediately tested. Pull-out forces for frozen groups were compared with pull-out forces for the fresh group. Using two-way ANOVA, there was no statistical difference in mean axial-extraction forces among bonepin specimen in any of the tested groups. It is concluded that acute pin pull-out forces are not significantly affected by freezing temperature or time. However, specimens stored at -20 C for as few as 14 days had a trend for increased pull-out forces, compared with freshly harvested specimens. Therefore, the authors recommend storage of bone-pin specimens at -70 C when possible.

The current study was designed to evaluate the influence of three different ground vegetable oil seeds on various physico-chemical, microbiological and sensory attributes of chicken sausages from spent broiler breeder hen stored under frozen (-18±1°C) condition. Chicken sausages were incorporated with ground poppy, sesame and peanut seeds each at 10 % level separately as three treatments and were analyzed for their keeping quality along with high fat control. The mean values of FFA, TBARS, tyrosine values, standard plate count, psychrophilic count and yeast and moulds counts were significantly (P&lt;0.05) influenced by formulation during frozen storage and values increased significantly (P&lt;0.05) throughout the storage period in all chicken sausages. Chicken sausages with ground sesame scored lowest standard plate counts (5.66 log CFU/g) than any others after 180 days of storage at 18±1°C. Coli forms, lacto bacillus and anaerobic counts could not be detected during entire storage period. Scores for all sensory attributes decreased significantly (P&lt;0.05) during storage in all treatments irrespective of formulation. Study proved that, the three ground vegetable oil seeds were effective by delaying the lipid oxidation, microbial growth and preserving sensory quality during frozen storage and among them ground sesame seed was more potent to be a better preservative.

An ELISA containing lipoarabinomannan (LAM) antigen was used to detect antibodies in milk and serum for diagnosis of Mycobacterium paratuberculosis infection in dairy cattle. In experiment 1, milk and serum samples were obtained from 25 cows, and subjected to LAM ELISA testing immediately, and after 1 year of storage at -70 C. Milk samples, with and without a commonly used chemical preservative, were tested. There was no significant difference in LAM ELISA results between fresh and frozen samples or between preserved and unpreserved milk samples. In experiment 2, milk samples were collected daily from 30 cows over a 14-day period. The day-to-day coefficient of variation was 0.19 for milk LAM ELISA and was 0.15 for serum LAM ELISA, with no statistically significant time effect detected. In experiment 3, single milk, serum, and fecal samples were obtained from 764 cows. The fecal samples were cultured for M paratuberculosis to identify infected cows, and the serum and milk samples were subjected to LAM ELISA testing. Results were compared, using the area under the receiver operating characteristic curves. The milk LAM ELISA had specificity (+/- 95% confidence limits) of 87 +/- 8.1% when the cutoff was set at 50% sensitivity, and specificity of 83 +/- 9.1% when sensitivity was set at 60%. The area under the receiver operating characteristic curve was 0.85 +/- 0.03 for the milk ELISA and 0.75 +/- 0.02 for the serum ELISA. In this population of cattle, the milk LAM ELISA had comparable accuracy to serum LAM ELISA, although the milk LAM ELISA was slightly less reproducible (higher coefficient of variation).

A commercially available radioimmunoassay kit for measurement of human osteocalcin was validated for use in horses. For accurate measurement of equine serum osteocalcin, blood samples may be collected at a temperature between 20 and 25 C, then centrifuged within 90 minutes; serum may be stored at - 20 C in plastic tubes for up to 26 weeks. Serum may be thawed and refrozen up to 5 times without significant change in measured equine serum osteocalcin concentration. Assay sensitivity was 0.16 ng/ ml. Recovery of bovine osteocalcin standard added to equine serum was linear. Intra-assay coefficient of variation (x 100) for 2 equine serum pools was 6.9 (mean +/- SD, 13.9 +/- 1.0 ng/ml) and 7.5 (10.6 +/- 0.8 ng/ml) %. Interassay coefficient of variation for 3 equine serum pools measured in 12 assays was 12.5 (16.1 +/- 2.0 ng/ml), 12.7 (11.5 +/- 1.5 ng/ml), and 24.6 (3.0 +/- 0.7 ng/ml) %. Dilutional parallelism was documented by assaying pooled equine serum at 4 dilutions and correcting the mean result for dilution. Significant change was not observed in equine serum osteocalcin concentration for various time-of-day blood sample collections in horses housed under continuous lighting.

Epidermal growth factor was injected intracamerally into the anterior chamber of the right eye of 9 cats. The central portion of the cornea in 8 of the 9 cats that had been cryoinjured. Effect of epidermal growth factor on the repair of endothelial cells in cats was evaluated by endothelial specular microscopy. Endothelial cell density and corneal thickness were studied quantitatively, as a measure of endothelial cell function. The repair process also was evaluated qualitatively by studying morphologic changes, developing as a result of reendothelialization and return to normal function. Seemingly, differences between rate of healing of cryoinjured eyes injected with epidermal growth factor and that in nontreated eyes were not significant (P = 0.86). The endothelial repair process was characterized by enlargement and migration of adjacent noninjured cells.