Se emplearon 5 vacas Holstein fistuladas del rumen para comparar el uso de marcadores internos y externos como estimadores de la tasa de recambio de la fase solida del rumen durante el ultimo tercio de la lactacion y el periodo seco, alimentadas cuatro veces al dia cada seis horas. Los marcadores extermos fueron: Cromo mordantado a la fibra detergente neutra del heno (Cr-FDN) e Iterbio unido a la FDN del residuo de destileria del concentrado (Yb-FDN). Se administraron 100 g de cada marcador directamente al rumen inmediatamente antes de cada alimento, divididos en 10 dosis de 10 g cada una (4 dosis al dia). La lignina y la fibra detergente neutra indigestible (FDNI) presentes en la racion fueron los marcadores internos. Cuatro horas despues de la ultima dosis de los marcadores externos, el contenido total del rumen fue evacuado manualmente, pesado y separado en contenido mixto, solido y liquido. La tasa de recambio de la fase solida se calculo como la relacion entre el contenido neto del rumen y el consumo de cada marcador. Se encontro una interaccion significativa entre marcadores y tipo de contenido en ambos estados fisiologicos, pero durante la ultima etapa de la lactacion los valores del contenido mixto tendieron a ser mas lentos para el Cr y el Yb (26.1 y 21.9 h, respectivamente) que para la FDNI y la lignina (22.9 y 16.0 h). La relacion entre los valores de tasa de recambio obtenidos con los marcadores internos y externos fue mejor en el contenido solido. En el contenido solido la correlacion entre Cr-FDNI y Cr-lignina fue de 0.76 y 0.72, y entre el Yb-FDNI e Yb-lignina 0.64 y 0.69, respectivamente. La tasa de recambio de la lignina y de la FDNI tuvieron una correlacion de 0.85 y 0.93 en los contenidos mixto y solido, respectivamente.

Se emplearon 5 vacas Holstein fistuladas del rumen para comparar el uso de marcadores internos y externos como estimadores de la tasa de recambio de la fase solida del rumen durante el ultimo tercio de la lactacion y el periodo seco, alimentadas cuatro veces al dia cada seis horas. Los marcadores extermos fueron: Cromo mordantado a la fibra detergente neutra del heno (Cr-FDN) e Iterbio unido a la FDN del residuo de destileria del concentrado (Yb-FDN). Se administraron 100 g de cada marcador directamente al rumen inmediatamente antes de cada alimento, divididos en 10 dosis de 10 g cada una (4 dosis al dia). La lignina y la fibra detergente neutra indigestible (FDNI) presentes en la racion fueron los marcadores internos. Cuatro horas despues de la ultima dosis de los marcadores externos, el contenido total del rumen fue evacuado manualmente, pesado y separado en contenido mixto, solido y liquido. La tasa de recambio de la fase solida se calculo como la relacion entre el contenido neto del rumen y el consumo de cada marcador. Se encontro una interaccion significativa entre marcadores y tipo de contenido en ambos estados fisiologicos, pero durante la ultima etapa de la lactacion los valores del contenido mixto tendieron a ser mas lentos para el Cr y el Yb (26.1 y 21.9 h, respectivamente) que para la FDNI y la lignina (22.9 y 16.0 h). La relacion entre los valores de tasa de recambio obtenidos con los marcadores internos y externos fue mejor en el contenido solido. En el contenido solido la correlacion entre Cr-FDNI y Cr-lignina fue de 0.76 y 0.72, y entre el Yb-FDNI e Yb-lignina 0.64 y 0.69, respectivamente. La tasa de recambio de la lignina y de la FDNI tuvieron una correlacion de 0.85 y 0.93 en los contenidos mixto y solido, respectivamente.

The responses to high temperature of the cyanobacterial symbiont and the host fern in tile Azolla–Anabaena symbiosis were studied by using Azolla strains with heterologous Anabaena azollae Strasburger of without Anabaena. At 26/18°C, symbiotic Azolla grew better than the corresponding Anabaena‐free Azolla. A high temperature‐sensitive species Azolla filiculoides Lamarck, produced smaller biomass under conditions of 37 °C (day)/29 °C (night) than the corresponding Anabaena‐free Azolla grown in N‐containing medium. A. filiculoides with Anabaena from temperature tolerant Azolla microphylla Kaulfuss was more effective at N₂ fixation than A. filiculoides with homologous Anabaena. A microphylla with Anabaena from A. filiculoides grew more slowly and fixed less N₂ than the strains with homologous Anabaena. In the presence of combined N at 37°/29 °C, A. microphylla grew better than A. filiculoides with Anabaena from A. microphylla. Tolerance of the Azolla‐Anabaena association to high temperature is, therefore, determined both in the host fern and symbiont Anabaena.

Comparisons of five pairs of isogenk lines of peas, differing only in the A gene for seed coat colour showed that white seeds (genotype aa) imbibed more rapidly than coloured seeds (AA), suffered greater imbibition damage revealed by dead tissue on the cotyledons, and higher solute leakage. Seed-coat pigmentation was closely associated with slow water uptake, since when expression of the A gene was suppressed by the recessive pollens gene, the resulting white seeds {palpal AA) imbibed rapidly. The slow water uptake by coloured seeds was not due to the restriction of water entry by the seed coat since the differences in imbibition rate were maintained when a portion of the seed coat was removed and seeds were imbibed with the exposed cotyledon in contact with moist filter paper. Imbibition of similarly treated seeds by immersion in polyethylene glycol solutions (1–4%) which increased the seed/solution wettability, had little effect on the water uptake of coloured seeds compared to imbibition in water whereas that of white seeds increased in the first 10 mins imbibition. Poor wettability of the inner surface of coloured seed coats did not therefore explain the slow imbibition of these seeds. The white seed coats loosened rapidly during imbibition whilst the coloured seed coats remained closely associated with the cotyledons suggesting that the adherence of the seed coat to the cotyledons and therefore the ease of access of water between the testa and cotyledons determines the rate of imbibition. The rapid water uptake by white-coated seeds and the subsequent imbibition damage may explain the high incidence of infection of these seeds by the soil-bome fungus Pythhan after 2 d in soil. Improved seed quality and emergence may therefore be achieved by breeding for seed coat characteristics leading to reduced rates of imbibition.

Im Rahmen der zweiseitigen Zusammenarbeit zwischen dem Institut fuer Zootechnik Krakow/Balice und dem VE Kombinat Tierzucht Paretz wurden in den PS Pawlowice und Ruhlsdorf die Schlachtleistungsparameter von Prueftieren nach den in beiden Laendern gueltigen Methoden parallel erfasst. Aufgrund von Regressionsrechnungen wurden Vergleichstabellen fuer die Parameter Fleischanteil (aus Regressionsgleichung) und Anteil Fleischteilstuecke, Fleisch der Keule und Anteil Keule, mittlere Rueckenspeckdicke, Rueckenmuskelflaeche sowie Baconlaenge und Innere Schlachtlaenge aufgestellt

Correlation between the quantity of haemolysin of 12 L. monocytogenes strains with different virulence grades and mouse virulence was investigated. The quantity of haemolysin was determined in a system using Cr51 marked ovine erythrocytes. The activity was expressed in the germ counts of bacterial suspensions showing a 50 per cent haemolysis. Mouse virulence of strains was calculated by the method of Reed and Muench, following intaperitoneal inoculations. Based on the correlation calculations of the results of repeated investigations in case of 9 strains, numerical correlation could not be found between the quantity of haemolysin produced by the Listeria strains and mouse virulence under the applied experimental conditions. It has been pointed out that the quantity of haemolysin does not play a decisive role in the mechanism of virulence of Listeria strains.

The specificity factors for ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) from six species of photosynthetic organisms are compared. The values were determined by measuring the oxygen uptake during the total consumption of ribulose-P2 in the presence of various concentrations of O2 and CO2. The specificity factors determined in this way were similar to values previously published; small but significant differences were found between the specificity factors of rubisco from C3 higher plant species.

Sudden abortion cases in masses existed in the pregnant Angora goats which were bought from Middle Anatolian region to be used in the scientific studies of our institute. On the date that thecase was seized it was observed that 10 of the 15 pregnant goatsmade abortion on ·the 130th- 140th days of their pregnancies andthere were no clinical symptoms in the mother goats. The placentalcotyledons and blood sera of the animals making abortion wereexamined in our laboratory for the direct and indirectdeterminationof the agent of the abortion in these goats. The blood seraof the mother goats were examined serologically iri regard to brucellosis,Salmonellosis, campylobacteriosis and chlamydiosis. 15 ofthe examined blood sera gave negative· reaction against bruceltosis.salmonellasis and campylobacteriosis. On the other· hand the presenceof the antibody titers which are specific in the diİution::: of1:32-1:128 for chlamydia psittaci infection were determined inthe same sera. The studies on the isolcition of agent of the chlamydla psittaci infection from the placental contyledons, kept in thedeep- frezer, fallawing the psitive results obtained from the serologicalexaminations the elementary corpuscles specific oor thechlamydia psittaci infection were determined in the microscopy ofthe preparations from the cotyledons. Thereupon the suspension ofplacental cotyledons: were prepared in the Tyrode solution ç:ontaining0.5 % streptomycine for the inoculatiıons of embryomıtedeggs and the guinea- pigs, for. the isolation of the agent. The cul~tivations and inoculations were done .in accordance with the techniques.The multiplication of the C. psittaci microorganisms were succededat -the end of the 4th guinea- pig passage and 2nd embryonatedeggs oulture passage.We have proven that the infection cousing to mass abortionsin the Angora goats, that were brought to our institute froriı MiddleAnatolia Region, is Chlamydia psittaci by the serological determinationof the antibodies which are specific for this disease by usingthe complementfixation tests. | İç Anadolu bölgesinden Enstitümüz, bilimsel çalışmalarında kullanılmak üzere satın alınan Ankara ırkı gebe tiftik keçilerinde ansızın kitle halinde yavru atma vak'ası çıkmıştır. Vak'aya el konulduğu tarihte 15 gebe keçiden 10 adedinin gebeliklerinin 130-140'ıncı günleri arasında abort yaptıkları ve ana keçilerde herhangi bir klinik hastalık belirtisinin bulunmadığı gözlenmiştir. Keçilerde çıkan abortuslarda etkenin direkt ve endirekt tespiti gayesiyle atık yapan hayvanların plasenta kotiladonlarıyla kan serumları alınarak laboratuvarımızda tetkik edildi. Ana keçilere ait kan serumları; brucellosis. salmonellosis, Campylobacteriosis ve chlamydiosis yönünden serolojik olarak muayene edildi. Tetkik edilen 15 kan serumu brucellosis. salmonellosis ve campylobacteriosis bakımından menfi reaksiyon vermiştir. Buna karşın aynı serumlarda Chlamydia psittaci enfeksiyonu için 1/32 1/128 dilüsyonlarda spesifik olan antikor titrelerinin varlığı saptanmıştır. Serolojik yoklamalarda alınan müsbet sonuç üzerine dipfrizde muhafaza edilen plesenda kotoladonlarından Chlamydia psittaci enfeksiyon etkeninin izolasyon çalışmalarına başlandı. Kotiladonlardan yapılan preparatlarda Chlamydia psittaci enfeksiyonu için spesifik olan elementer cisimcikler mikroskopide tespit edildi. Bunun üzerine etken izolasyonu için embryonlu tavuk yumurtası ve kobay inokulasyonu için plasenta kotiladonlarından % 0,5'lik streptomycinli Tyrode eriyiği içinde suspensiyon hazırlandı ve gerekli tekniklerine göre ekim ve enjeksiyon yapıldı. Dördüncü kobay ve ikinci embryonlu tavuk yumurtası kültürü pasajı sonunda Chlamydia psittaci mikroorganizmlerinin üretilmesine muvffak olundu. Kitle halinde yavru atan Ankara Tiftik keçilerine ait plesenta kotiladonlarından gerek embryonlu tavuk yumurtası kültürlerinde yumurta sarısı zarından ve gerekse kobay inokulasyonlarında Chlamydia psittaci mikroorganizmlerinin üretilmesi ve gerekse abort yapan ana keçilerin kan serumlarında Chlamydia psittaci enfeksiyonuna karşı bu hastalık için spesifik olan antikolarların serolojik olarak komplement-fixasyon testiyle tespiti: İç Anadolu bölgesinden Enstitümüze getirilern Ankara tiftik keçilerinde kitle halinde abortüslere neden olan enfeksiyonun 'Cylamydia psittaci' mikroorganizmlerinden ileri geldiği tarafımızdan kanıtlanmıştır.