Pulmonary mechanics measurements in normal calves.

The mechanics of ventilation were assessed in 25 normal conscious crossbred calves and immature cattle, aged 24-406 days and weighing 60-360 kg. An oesophageal balloon was used to measure transpulmonary pressure and a pneumotachograph attached to a face mask measured respiratory flows. A regression analysis with body weight as the independent variable and pulmonary function values as the dependent variables demonstrated growth related changes in pulmonary function, confirming those previously described. Mean pulmonary function values differed in a number of respects from previously reported values for cattle of similar size. The response of individual cattle to the pulmonary function testing procedure probably accounted for a major part of these differences.     

Volume-controlled bronchopulmonary lavage of normal and pneumonic calves

Saline bronchopulmonary lavage of the right lung of 16 anesthetized calves was performed using a single-lumen cuffed endotracheal tube. The initial volume of saline introduced was based on the functional residual capacity (FRC) of the right lung lobes as determined from the proportional weights of the right (58% of total FRC) and left (42% of total FRC) lung lobes. Calves were divided into "pneumonic" and "normal" groups based on clinical signs. Five sequential washes were done on each calf. There was no difference in the percentage of total lavage fluid volume recoverable between normal (83.8 +/- 4.2%) and pneumonic (81.1 +/- 8.2%) calves. Cell yield in the initial wash was consistently greater than in subsequent washes for both normal (12.7 +/- 6.6 X 10(6) cells/kg body weight) and pneumonic (58.1 +/- 37.6 X 10(6) cells/kg body weight) calves, and constituted 62.0% (normal) and 75.4% (pneumonic) of the total recoverable cell yield. Total cell yields were higher (P less than 0.05) in pneumonic calves, primarily due to neutrophil leukocytes (PMN). Neutrophils constituted 53.7 +/- 25% of the total cell yield in the pneumonic calves, but only 12.3 +/- 9.5% in the normal calves. The pulmonary alveolar macrophage (PAM) was the major recoverable cell in normal calves (85.7 +/- 8.7% of total lavage cells). Macrophages constituted a smaller (42.9 +/- 23.5) percentage of the total lavage cells in the pneumonic group due to increased PMN numbers. Viability of recovered cells from the pneumonic calves (91.5 +/- 4.8%) was lower than for the normal calves (94.1 +/- 2.5%), but the difference was not significant.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ferrokinetic studies in normal and iron deficiency anemic calves.

Ferrokinetic studies were performed on control calves and on calves with experimentally induced iron deficiency anemia, all 15 weeks old.The plasma iron clearance half time was about 4 times shorter in the experimental than in the control group. The low plasma iron concentration in the anemic calves was partially compensated by a more rapid plasma iron disappearance. Therefore the difference in the plasma iron turnover rate was reduced.The mean value of plasma iron daily renewal rate was about 3 times higher in the experimental than in the control group.The maximum uptake of injected ⁵⁹Fe into blood cells was reached 14 to 16 days after injection. The uptake of ⁵⁹Fe was about 10% higher in the control than in the experimental group.Using the values from the ferrokinetic study, the iron need for calves could be estimated. The requirement of iron to maintain a normal and constant Hb in a calf weighing 100 kg at a growth rate of 1 kg/daily was estimated as being 17.5 mg/day. Based on information in the literature and assuming a retention of dietary Fe of 25%, the total daily iron need for such a calf gaining 1 kg/day would be 160–180 mg.     

Pathology of natural rotavirus infection in clinically normal calves

During a longitudinal study of the epidemiology of rotavirus infection in a calf rearing unit, excretion of virus in faeces was detected by enzyme-linked immunosorbent assay in 40 of 48 (83 per cent) unweaned calves aged between three days and five weeks. Fifty per cent of the infected calves had no clinical signs of disease. Enterocytes containing rotavirus antigen and intestinal lesions were found in all of 12 clinically normal calves selected for necropsy between days 1 and 4 of virus excretion. Stunting and fusion of villi, exfoliation, disarrangement and vacuolation of enterocytes and the presence of cuboidal enterocytes were observed in infected calves but not in rotavirus-free control calves. Lesions predominated in the upper small intestine, where rotavirus was most abundant, especially on the first two days of virus excretion. The numbers of enterocytes infected with rotavirus diminished before the lesions resolved.     

Peritoneal fluid values and collection technique in young,normal calves

Peritoneal fluid from 10 healthy young male Holstein calves was analyzed three times (2 to 3 days, 12 to 15 days and 27 to 30 days) during the first month of life. A new technique for collection of peritoneal fluid from calves positioned in left lateral recumbency was developed. The technique was found to be reliable and without noticeable complications. Mean peritoneal fluid nucleated cell counts, red blood cell counts, and absolute counts for mononuclear cells, lymphocytes and eosinophils did not change significantly (P 相似文献   

Plasma growth hormone and insulin concentrations in double-muscled and normal bull calves

Blood samples were taken from 19 double-muscled (DM) and 20 normal (N) bull calves at the ages of 1.5, 2, 2.5, 3, 3.5, 4, 5.5, 6.5 and 9 mo to compare the plasma concentrations of growth hormone and insulin in DM with those in N bull calves and to relate these to differences in growth rate between the two breed groups. Double-muscled bull calves were lighter (P less than .0001) than N calves at all ages and had lower (P less than .001) preweaning and postweaning rates of gain. Double-muscled bull calves had lower (P less than .01) mean growth hormone concentration than N calves. Mean growth hormone concentration was correlated positively with body weight and preweaning rate of gain. The effect of age on growth hormone concentration was linear (P less than .05); however, mean growth hormone concentration fluctuated between ages 1.5 to 4.5 mo but stabilized after 5.5 mo of age in both breed groups. Mean insulin concentration was lower (P less than .01) in DM than in N bull calves. The effect of age on insulin concentration was both linear and quadratic (P less than .0001). Mean insulin concentration generally was constant in both breed groups, at around .75 ng/ml, from 1.5 to 6.5 mo of age but rose sharply to around 1.67 ng/ml after weaning when the bulls were put on a high-energy diet.     

Systemic mycotic lesions in apparently normal bobby calves: Incidence and appearance

Extract

During the routine examination of slaughtered bobby calves at the Westfield Freezing Works, Otahuhu, liver lesions thought to be either an atypical form of congenital tuberculosis or actinobacillosis were encountered. Further investigations showed these lesions to be of fungal origin (D. O. Cordes, pers. comm.). The purpose of this communication is to describe the incidence and macroscopic appearance of these mycotic lesions.     

高原山羊血气分析

有血气分析仪对２１只高原山羊进行血气分析，结果：ｐＨ７．３５±０．０５，ＰＣＯ２４．７４±０．４２ｋＰａ，ＰＯ２３．７９±１．０５ｋＰａ，ＨＣＯ－３２０．０８±３．０３ｍｍｏｌ／Ｌ，ＴＣＯ２２１．９±３．０７ｍｍｏｌ／Ｌ，ＢＥ－４．９８±２．３１ｍｍｏｌ／Ｌ，ＳＢＣ　２０．２５±２．６５ｍｍｏｌ／Ｌ，ＳＢＥ－６．１９±２．８６ｍｍｏｌ／Ｌ，Ｏ２Ｓ％４９．４７±１４．８。表明血气值在不同性别、不同年龄间无显著差异（Ｐ＞０．０５）。     

The kinetics of mononuclear phagocytes in normal calves given Corynebacterium parvum.

Two groups of calves, three in each group, were used to determine the kinetics of mononuclear phagocytes in normal calves and in calves given Corynebacterium parvum intravenously, using tritiated thymidine as an in vivo deoxyribonucleic acid label. In normal calves, the mean production time of labelled monocytes in the bone marrow was 36.4 +/- 2.04 hours. The turnover rate of labelled monocytes from the bone marrow into the peripheral blood was 5.4 +/- 0.3% per hour and the disappearance rate of labelled monocytes from the circulation was 0.9 +/- 0.3%. The half lives of labelled blood monocytes were 22.5 hours for cells with 16-30 grains and 19.5 hours for cells with 31-50 grains. Alveolar macrophages were derived from peripheral blood monocytes. In calves given C. parvum, the production time, turnover rate and half lives of labelled monocytes did not differ significantly (p greater than 0.05) from the values in normal calves.     

黑白花奶牛静脉血血气分析

用IL 130 2型血气分析仪对 2 1头黑白花奶牛的静脉血血样进行血气分析。结果 :pH7 35± 0 0 3,Pco2 4 .82± 0 52kPa ,Po2 3 79± 0 57kPa ,O2 S % 50 6 1± 10 .0 8,HCO3- 2 0 12±2 .71mmol/L ,Tco2 2 1 18± 2 81mmol/L ,BE 5.0 2± 2 45mmol/L ,SBE 6 .14± 2 .82mmol/L ,SBC2 0 2 2± 2 0 5mmol/L     

ELISA to determine anti-K99 pilus antibody in the sera of normal and diarrhoeic calves

An ELISA to detect circulating antibodies against K99 pili, a major attachment factor to intestinal epithelial cells of Escherichia coli in calves, was performed. Two methods of K99 pili purification were attempted. Best results in terms of purity of the K99 antigen were achieved following the method described by Karkhanis and Bhogal (1986). This procedure included a heat shock at 65°C during 25 min to release the pili and ultracentrifugation steps to purify the antigen. SDS-PAGE showed an 18 KDa major band, identified as the K99 pilus antigen after immunoblotting against reference antisera. The purified K99 antigen was then adsorbed to the ELISA microplates. High optical density was obtained in the ELISA using a pool of sera from immunized cows. No differences in antibody levels (P ≥ 0.05) could be detected between clinically healthy calves and those showing diarrhoea.     

Isolation of Pasteurella haemolytica and correlation with serum antibody response in clinically normal beef calves

Bacteria from the nasal cavity and trachea were cultured, and serum antibody titers determined for Pasteurella haemolytica serotype 1 in 164 beef calves obtained from a closed herd on range pasture. At the first sampling, P. haemolytica serotype 1 was cultured from 16.4% of the calves. Antibody titers were determined by a quantitative fluorimetric method and the mean titer was 9.5 +/- 5.8. Fifty-seven randomly selected calves were used to study the correlation of serum antibody response and positive culture of P. haemolytica under natural conditions. Clinical signs of respiratory disease were not observed in those calves. During the observation periods, there was a two-fold increase in the percentage of calves that were culture positive. There was no significant difference between mean serum antibody titers or frequency distribution of antibody titers from the two samplings. Comparisons between serum antibody titers, rise in titers, and P. haemolytica isolation failed to reveal any significant correlation. Of the 9 calves that had a decline in antibody titer to P. haemolytica, none was culture positive. Seroconversion to respiratory viruses did not correlate with P. haemolytica related variables.