The effect of propionic acid on the storage losses of hay

Storage losses in moist hay treated with propionic acid were compared with those occurring in untreated moist hay in two experiments and with field-cured hay in three experiments. Dry matter losses in treated hays ranged from 41 to 8.6% and from 1.7 to 12.6% in untreated hays. Digestible organic matter losses in both treated and untreated hays were generally greater than dry matter losses. Only in one experiment did propionic acid application significantly reduce nutrient losses in moist hays. Nutrient losses, and water-soluble carbohydrate losses in particular, were shown to be correlated with maximum and cumulative bale temperatures during storage in two of the experiments. The rise in hale temperatures during storage was reduced in all three experiments, to a greater or lesser extent, by application of the additive. Loss of propionic acid from the hay during and after application was very large. In the three experiments 86.2, 85.3 and 85.6% of the acid applied was lost by the end of the storage period. Acid distribution studies indicated that variation in acid concentration within bales was as great as between bales. It was concluded that more research is needed into applicator design and position on the baler and into alternative application methods if the benefits of propionic acid as a moist hay preservative are to be fully exploited.     

Studies on Herpesvirus scophthalmi infection of turbot Scophthalmus maximus (L.): Histopathological observations

Abstract. The histological features of the disease caused by infection of turbot by Herpesvirus scophthalmi are described. Infection of epidermal cells of skin and gill resulted in the formation of giant cells showing a variety of nuclear and cytoplasmic changes associated with the replication of the virus. The effects of the condition together with possible control measures are discussed.     

INVESTIGATIONS ON THE DRYING OF HERBAGE AT TEMPERATURES UP TO 50°C*

Experiments to determine the exposed layer drying rate of cut leaves and stems of a tetraploid (Sabel) and diploid (S23) ryegrass are described. Drying was achieved by passing air through the crop; the changes in weight were monitored continuously. Airflow was fixed throughout the experiments at 37·5 ft/min (0·190 m/s) and the temperatures were controlled in the range 25°C to 50°C. Comparisons were also made of the drying rates at different stages of maturity. Drying curves were determined and moisture content was shown to decay exponentially with time, the relationship approximating closely to a two term exponential.     

THE EFFECT OF THE BIPYRIDYL HERBICIDES ON HILL COMMUNITIES AND THEIR ROLE IN THE IMPROVEMENT OF HILL GRAZING

The improvement of hill land is important to the national economy of the United Kingdom. An increase in the amount of enclosed productive land results in a greater stock-carrying capacity of a hill farm. Improvement is not always possible by conventional implements, and herbicides are being used to kill the old sward. The bipyridyl herbicides offer a means of destroying or modifying the indigenous vegetation. The application of low doses of paraquat or diquat to an association containing Molinia caerulea, Nardus sfricta and Festuca avina resulted in a change in equilibrium in favour of the fescues. The application of 2 lb paraquat per acre practically eliminates all grass species in a sward and it is then possible to establish desirable pasture species after lightly cultivating the dead surface litter.     

THE EFFECT OF HISTAMINE ON SILAGE DRY-MATTER INTAKE

The oral introduction of 0·5 g histamine as the diphosphate into the rumen of sheep produced no effect on the physiological condition of the animals. The feeding of histamine, as the dihydrochloride, in levels up to 1 g/day to sheep on silage diets did not affect the dry-matter intake.     

Nekrosen an kartoffelkeimen,ein Symptom von Mosaikviren

Zusammenfassung In Erg?nzung der Angaben vonMartin undQuemener übe eine Fleckung belichteter Dunkelkeime infolge Infektion durch Mosaikviren wurde festgestellt, da? auchNekrosen auftreten k?nnen. Diese sind das Anzeichen einer schweren Erkrankung. Bei den untersuchten Sorten waren sie in der überwiegenden Mehrzahl der F?lle durch Mischinfektion mit Y- und X-Virus verursacht, doch werden nicht alle diese Infektionen durch die Entwicklung von Nekrosen kenntlich. Keime mit Nekrosen bleiben meist in der Entwicklung zurück; bei Farbfleckung ist diese Wachstumsdepression im allgemeinen schw?cher ausgepr?gt.

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Summary Martin andQuemener found that tubers infected with mosaic viruses could be recognized by the irregular spotty coloration which, after exposure to light, developed on sprouts grown in the dark. If the symptoms are very marked (heavy crinkle or streak), especially in the case of mixed Y and X virus infections, necroses appear on the sprouts in addition to or instead of the coloured spots, especially at their bases. These necroses are very different from the nonviral “necrobioses” of the sprout apex or cell elongation zone 1–2 mm below the tip. The necrotic virus spots are of a lighter, brownish colour than the blackish-brown necrobioses, which frequently form stripes running from tip to base. Necrotic sprouts usually exhibit a pronounced decline in growth. Development of sprouts showing only irregular spotty coloration is less inhibited. When examining potato tubers for mosaic virus infection necroses can be regarded as a additional symptom to the irregular spotty coloration. Sprouts 3–5 cm in length grown in the dark were exposed to daylight for some days. The testing of sprouts developed after desprouting gives better results than the testing of the original sprouts. Moreover, the number of tubers with necrotic sprouts increases with increasing sprout age.

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Résumé Martin etQuemener signalent que les tubercules infectès par les virus des mosa?ques peuvent étre reconnus à la coloration en taches irrégulière qui apparait sur les germes cultivés dans l'obscurité lorsqu'on les expose à la lumière. Si les sympt?mes sont tres prononcés (forte frisolée ou bigarrure), surtout dans le cas des infections mixtes à virus Y et X, les colorations en taches des germes sont accompagnées ou remplacées par des nécroses, surtout à la base des germes. Ces nécroses sont toutes différentes des “nécrobioses” non provoquées par des virus, que l'on trouve à la pointe des germes ou dans la zone d'allongement cellulaire à 1 ou 2 mm au dessous de la pointe. Les nécroses à virus ont une couleur brune plus claire que les nécrobioses brun-noir, qui forment souvent des lignes allant de la pointe à la base ddu germe. En général, la croissance des germes nécrotiques est nettement réduite. Le développement des germes présentant uniquement une coloration en taches irrégulière est moins fortement retardé. A l'examen des tubercules de pomme de terre relatif aux virus des mosa?ques, les nécroses peuvent être considérées comme un sympt?me supplémentaire à c?té de la coloration en taches irrégulière. Les germes de 3 à 5 cm de longueur poussés dans l'obscurité sont exposés à la lumière du jour pendant quelques jours. L'examen des germes qui ont poussé après l'enlèvement des germes déjà présents fournit de meilleurs résultats que celui des premiers germes apparus. De plus, le nombre de tubercules à germes nécrotiques augmente avec l'age des germes.