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191.
Radiocarbon dates associated with engraved stones from sealed archeological deposits at Wonderwerk Cave in the northern Cape Province indicate that rock engraving in South Africa is at least 10,000 years old.  相似文献   
192.
Antibodies specific for Brucella abortus were purified from the serum of hyperimmunized sheep using immunochemical procedures. They were conjugated to fluorescein isothiocyanate and used in a fluorescent antibody (FA) test for B. abortus. The conjugate did not stain any heterologous bacterial or fungal species tested and background fluorescence associated with its use on smears and sections of abortion materials was particularly low. Of 239 cases of abortion examined fluorescent microscopy demonstrated B. abortus in all 12 cases in which the organism was isolated. A few areas of fluorescence typical of B. abortus were also seen in 3 cases from which the organism was not cultured. B. abortus was demonstrated in lymph nodes from 6 of 36 Brucella reactor cows by culture and 7 by the FA test. However, only very low numbers of B. abortus were isolated or seen and sampling errors would have been significant. Use of the FA test allows diagnosis of Brucellosis to be made in 2 hours, compared to 6 days by the usual cultural procedures.  相似文献   
193.
The effect of seven fertilizers on the viability of Taenia saginata eggs was tested in vitro. The most destructive effect was produced by lime-nitrogen, in which the eggs survived only for 24 hours in the substance and for two days in a saturated solution. In the limestone the eggs survived for three days.  相似文献   
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1. The α‐tocopherol (AT) content of abdominal fat and fat stability increased as a function of the duration of α‐tocopheryl acetate (ATA) feeding in broilers fed on diets containing either 40 g acidulated soyabean‐oil soapstock (ASS) or tallow/kg. A linear relationship was observed between AT content of the adipose tissue and its stability with both types of fat supplements.

2. The stabilities of carcass fat and meat of 9‐week‐old broilers fed on diets containing ASS with 300 mg ethoxyquin (EQ)/kg or diets containing tallow with 20 mg ATA/kg from weeks 5 to 9 were comparable with those obtained by feeding these antioxidants and fats throughout the growth period.

3. ATA added to a diet containing ASS, and EQ, added to a diet containing tallow did not improve meat stability despite such an effect on adipose tissue when fed for 9 weeks. The results emphasise the importance of using the dietary antioxidant appropriate to the fat supplement to improve carcass stability.  相似文献   

196.
1. n‐Paraffin‐grown yeast and a mixture of soyabean meal and fish meal were compared in the net protein utilisation (NPU) test, and as protein supplements in diets for broilers up to 4 weeks of age.

2. The difference between the NPU values, 0.66 for yeast and 0.80 for the soyabean meal and fish meal mixture, could largely be attributed to the high nucleic acid content of the yeast.

3. Chicks given the diet containing yeast (190 g/kg) did not grow as rapidly as those given the soyabean meal and fish meal reference diet, and the reduced growth could only partly be explained by a marginal deficiency of methionine.

4. Food conversion efficiency with the yeast diet was improved by maize oil while responses to α‐tocopheryl acetate and sodium selenite were inconsistent.

5. Chicks grew well when yeast replaced fish meal in the mixture of soyabean meal and fish meal, and when fish meal (194 g/kg diet) was the sole protein supplement.  相似文献   

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Parainfluenza-3 (Pi3) virus infection in a group of 25 calves is described. The virus was isolated from the lungs of four calve at days 6, 7, 13 and 55 after they were housed together at birth. Intracytoplasmic inclusion bodies were seen by light microscopy in bronchial and bronchiolar epithelial cells of two of these calves. Virus infected cells were detected by electron microscopy in three of the four calves. Haemagglutination inhibition antibodies to Pi3 virus were found in the sera of the calves. Despite the virus being present in the group from one week, a significant increase in antibody titre was found in only two animals although all the calves were in contact with each other during the study period. The pulmonary lesions in the four infected calves consisted of a bronchitis and bronchiolitis with infiltration of the walls and lumena of these structures by neutrophils and an adjacent neutrophil infiltration of alveoli some of which were collapsed.  相似文献   
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