During the war a shortage of fish oils developed in Palestine owing to the interruption of imports. Green plants had therefore to supply most of the vitamin A requirements of poultry. In order to determine the amounts of green plants necessary to cover this requirement, systematic analyses were made of their respective carotene content. These investigations were further to determine which fodder plants and hays are the most suitable for the feeding of cows for production of butter fat rich in carotene and vitamin A.The carotene content of the usual fodder plants was determined with special regard to the influence of the season of growth and of the age of the plants. Influences of this kind are of special importance in Palestine, where plants are cultivated all the year round and where summer and winter climates diverge widely, rain falling only in the winter months between October and March (annual average in Rehovot 577 mm.). Additional determinations of carotene were carried out on vegetables, their refuse and some wild plants, all of which are employed for poultry feeding. METHODSFrom each forage plant to be investigated at least two representative samples of about 1 kg. were collected by cutting off the plants about an inch above ground. Small handfuls were taken at random throughout the field. The fields to be sampled were in the neighbourhood of Rehovot, and the samples were forwarded to the laboratory immediately after cutting. About 300 g. fresh material were ground through a food chopper, mixed thoroughly (see Snyder & Moore, 1940), and 10-25 g.-according to the expected carotene content-were at once weighed for carotene determination in a mortar and covered with ethanolic potassium hydroxide. Sand was added and the tissue was ground thoroughly. The carotene content was then determined by Guilbert's method (1934) as modified by Peterson, Hughes & Freeman (1937). The different steps of this method were carried out in dim light and as rapidly as possible. To accomplish the determination rapidly only a small number of samples were investigated simultaneously. Experiments carried out by Pepkovitz (1944) showed that these precautions-particularly rapid separation of carotene and chlorophyll-assure that losses of carotene are avoided. The carotene was not separated into several fractions, since according to Kemmerer, Journ. Agric. Soi. 36Fudge & Fraps (1942) carotene in green plants contains 94-98 % of /S-carotene.The results of two or more different samples from the same field, as described above, were in close agreement and the differences did not exceed 5 %. Other authors, such as Fraps (1938), Moore (1940), Benne (1942), etc., found that the method of Peterson et al. is entirely satisfactory for carotene determination in green plants. According to Moore (1940) practically identical results are obtained with this method as with methods developed recently • and based on cold extraction with different solvents and on the separation of pigments by adsorption.Determinations of dry matter were carried out separ...
1. Egyptian clover, sweet lupin, Lathyrus ochrus, Eragrostis tef and Vicia narbonnensis have been analysed as to their hexosan, pentosan and lignin content. The major part of the pentosan is soluble in 2 % HCl and therefore belongs to the hemicellulose fraction, whereas most of the hexosan is insoluble in 2 % HCl and forms part of the cellulose fraction.2. The digestibility of hexosan, pentosan and lignin has been determined by experiments with sheep. The digestibility of soluble pentosan and of insoluble hexosan (2 % HCl) was found to be very constant. It ranged from 64·0 to 66·2 % for pentosan and from 74·1 to 76·5 % for hexosan. ·Lignin was in all cases digested comparatively well, the digestibility coefficients being markedly variable, depending on the plant material. They ranged between 35·1 and 64·0.3. Faeces lignin yields lower methoxyl values than plant lignin. Therefore lignin appears to have been changed during passage through the animal body.4. The partition of hexosan, pentosan and lignin on crude fibre and N-free extract prepared from different plant materials is markedly variable.5. The major portion and best digestible fraction of plant lignin is soluble in alkali and is, therefore, contained in the N-free extract.
The objectives of this experiment were to assess effects of animal age and castration on activities of calpain I, calpain II, and calpastatin in sheep skeletal muscle. Ten newborn male lambs (2.9 kg), six weaned wethers (23.2 kg), six weaned rams (22.2 kg), six market wethers (55.4 kg), and six market rams (60.2 kg) were slaughtered and samples of biceps femoris were taken for assay of calpain I (micromolar calcium-dependent proteinase), calpain II (millimolar calcium-dependent proteinase), and calpastatin. Preweaning weight gain was similar for rams and wethers; however, postweaning ram growth exceeded (P less than .05) that of wethers. Ram biceps femoris weights at market were greater than those of wethers (P less than .05). Irrespective of age or gender, activity of calpain II was two- to threefold greater than that of calpain I. Muscle calpastatin activity was severa fold higher than calpain I and II activities. Activities of calpains and calpastatin declined (P less than .05) between birth and weaning. A portion of these losses were due to a dilution effect caused by accumulation of muscle proteins. Neonatal attenuation of calpain activities may underlie age-related attenuation of fractional rates of muscle protein degradation. Although ram muscle growth exceeded that of wethers, no differences (P greater than .05) in activities of muscle calpains or calpastatin were detected between these two groups at weaning or at market weight. Hence, castration did not influence lamb muscle growth by altering muscle calpain or calpastatin activities.
A suitable modification of the microbiological method for assaying pantothenic acid was developed and the pantothenic acid content in various kinds of poultry-feeding stuffs determined by its use. To assure quantitative liberation of the total amount of the pantothenic acid from the samples it is recommended to digest the samples first with Clarase.Pantothenic acid content was determined in poultry feeds of animal origin, such as fish-meal, meat-scrap, liver-meal and different kinds of milk-powder. It is remarkable that different kinds of fish-meal differ markedly in their pantothenic acid content.
Digestibility trials with poultry were carried out with dura, carobs and hide-fleshings.1. Dura equals the feeding value of corn and exceeds that of wheat, barley and oats. The high feeding value of dura is due to the large amount of easily digestible starch, and to the very small percentage of crude fibre.2. Carobs. The main nutrient factor in carobs is represented by the totally digestible sugars contained in the N-free extract. Protein and crude fibre are not digested to any appreciable extent. The feeding value of carobs was compared with that of grain foodstuffs.3. Hide-fleshings are a by-product of the tanneries. They contain 66·25 % of protein, which is digested by poultry like meat-meal protein (89·9 %).The authors wish to thank Mrs Gnessia Rabinovicz for her untiring assistance in the execution of these experiments.
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