bluuebunny/crossref_metadata_2025_split huggingface dataset:
195. Urea as a protein substitute in the diet of young cattle
Authors: Bartlett S. , Cotton A. G. 
Published: June 2009

1. A 142-day feeding experiment with twenty-one dairy heifers aged 7–17 months is described.2. The addition of 0·127 lb. per animal per day of urea to a diet supplying a limited amount of protein resulted in an extra daily live-weight increase of 0·24 lb. per day. This increase was statistically significant and the animals appear therefore to have utilized the urea nitrogen in their metabolism.3. Animals receiving the same quantity of additional nitrogen in the form of protein showed slightly better live-weight gains than those receiving the urea; although the difference was not significant it seems probable that the protein was a more efficient nitrogen supplement than urea.
212. Studies in mastitis. IV. Mastitis in relation to the methylene blue reduction test
Authors: McClemont J. , Davis J. G. 
Published: June 2009

The adoption of the methylene blue test as an official method of grading milk in England makes this subject one of considerable importance. The predominating factor in this, as in other tests, is the condition of storage (time and temperature) of the sample. If mastitis affects the methylene blue reduction time of milk the factors responsible may be any or all of the following:(1) The mastitis organisms themselves.(2) Other organisms present (secondary invaders).(3) Body cells, e.g. the so-called leucocytes of milk and also blood cells.(4) Chemical changes in the milk as the result of the mastitis.A related aspect is the value of the methylene blue test on single cow or quarter samples as a test for mastitis.
215. The value of indirect methods for the detection of mastitis
Authors: Rowland S. J. , Zein-El-Dine M. 
Published: June 2009

The following indirect tests for the detection of subclinical mastitis were applied, under bacteriological control, to a series of milk samples from the individual quarters of cows in full milk: presence of clots, reaction to bromcresol-purple, reaction to brom-thymol-blue, amount and character of centrifuge deposit, catalase content, chloride content, casein number and solids-not-fat content.These tests detected 12, 61, 14, 55, 49, 77, 91, and 63% respectively of the infected quarters, and diagnosed 0, 16, 0, 3, 34, 0, 8, and 9% of the uninfected quarters as infected.For each indirect test the mean square contingency was calculated as a measure of agreement between it and the direct bacteriological method. The tests were placed in the descending order of their value for diagnosis thus: casein number, chloride content, centrifuge deposit, solids-not-fat content, brom-cresol-purple reaction, brom-thymol-blue reaction, presence of clots, catalase content.
236. The bacterial flora of New Zealand Cheddar cheese
Authors: Sherwood I. R. 
Published: June 2009

Of the lactic acid bacteria isolated, 720 strains from thirty-six typical Cheddar cheeses have been classified. The dominant organism in New Zealand cheese has been shown to beSbm. plantarum. Sbm. caseioccurs much less frequently, while betabacteria and betacocci are found in still smaller numbers. Betabacteria tend to replaceSbm. plantarumin the final stage of cheeseripening. The flora of good quality cheese has been found to consist mainly of one or two varieties ofSbm. plantarum, often associated with Sbm. casei or a small proportion of betabacteria. In poor-quality cheese a larger number of types of lactic acid bacteria frequently occur. A simple routine method is described for distinguishing the different groups present in cheese.The effects which different strains of lactobacilli and betacocci produce in cheese have been correlated with their biochemical characteristics.Sbm. caseiin general appears to be beneficial to cheese quality. The strains ofSbm. plantarumisolated have been grouped in four varieties, mainly on the basis of sugar reactions; one variety has been shown to be beneficial to cheese quality, another variety has very little apparent effect, while the remaining two varieties produce serious defects—bad flavours, discoloration and, occasionally, open texture. The same defects are produced by most strains of betabacteria and betacocci when present in large numbers.The biochemical characteristics of the lactobacilli studied have shown a more regular gradation fromSbm. caseithroughSbm. plantarumtoBbm. breve(the only species ofBetabacteriumisolated) than is indicated from the generally accepted systems of classification.
241. Kay and Graham's phosphatase test: (a) Modifications in technique (b) Effect of bacterial growth
Authors: Neave F. K. 
Published: June 2009

1. By the use of sodium hexametaphosphate it is possible to eliminate the final filtration in the phosphatase test, and thus appreciably to shorten the time required for the test.2. It is necessary to avoid direct sunlight during that part of the test in which Folin's reagent is in use. Other minor precautions are mentioned in the paper.3. The pH. of the milk samples tested was found to vary naturally before pasteurization from pH 6·5 to 6·9 without affecting the validity of the test.4. The test is also unaffected by the presence in milk of bacteria which produce reducing substances or which hydrolyse the substrate (sodium phenyl phosphate) unless the organisms are present in very large numbers.
243. Factors affecting the solubility of milk powders. IV. The influence of speed and duration of stirring on solubility, with a description of a rapid method for solubility determinations
Authors: Howat G. R. , Smith J. A. B. , Waite R. , Wright N. C. 
Published: June 2009

1. The effects of alterations in the duration and speed of stirring on the apparent solubility of milk powders have been investigated. It is concluded that 30 sec. shaking of the powder reconstituted in a 10 % mixture is sufficient to dissolve the truly soluble portion of the dried milk, but that the protein which has become denatured during the drying process tends to pass into solution with increasing speed and duration of stirring.2. A rapid method for estimating the solubility of milk powders on a total solids basis involving only 1 min. shaking is described and discussed.3. The sediment method frequently used in industry as a guide to the solubility of dried milks is compared with the rapid method described in the present paper. At higher solubilities the sediment volume may serve as a guide to small changes in solubility, but in the lower solubility ranges its usefulness is very limited. It is shown that the washing of the sediment with one or more changes of water merely introduces additional errors into this method of solubility determination.
252. The effect of commercial pasteurization and sterilization on the vitamin B1 and riboflavin content of milk as measured by chemical methods
Authors: Houston J. , Kon S. K. , Thompson S. Y. 
Published: June 2009

1. Fluorimetric tests applied to commercially pasteurized and commercially sterilized milk showed that in the former some 10% and in the latter up to 50% of vitamin B1 was destroyed in the course of the heat treatment.2. Riboflavin withstood both treatments without loss.3. These findings are in satisfactory agreement with the results of earlier biological tests.
285. Studies on experimental teat and mammary development and lactation in the goat
Authors: Folley S. J. , Watson Helen M. Scott , Bottomley A. C. 
Published: June 2009

1. Observations on five animals indicate that the teats of immature castrated male goats grow isometrically. Less extensive data on three animals allow of the tentative conclusion that the same is true of immature normal males. In the male goat therefore teat growth appears to be uninfluenced by the testes.2. Administration of diethylstilboestrol or its dipropionate to normal or castrated immature male goats causes the teats to grow allometrically for a time.3. No externally visible udder growth occurred even when oestrogen treatment was prolonged for periods of over a year and was supplemented by progesterone or ethinyltestosterone. Whole mounts of glands from treated animals indicated that some mammary growth had occurred. In two cases microscopic examination showed the presence of alveoli. No explanation can be offered of the failure to develop the udder in the male goat experimentally.4. Endocrine activity of the ovary as evidenced by a change from isometric to allometric teat growth often manifests itself in the young female goat at an early age. In one case allometric teat growth was in progress at 41 days of age. During the allometric phase the data agree with the simple allometric law.5. During the rutting season following its birth, teat growth ceases completely in the female goat; allometric growth is resumed when the rutting season ends. It therefore appears that the corpus luteum inhibits teat growth.6. Administration of diethylstilboestrol or its dipropionate (by inunction of the udder region) causes, in the virgin female, an increase in the rate of teat growth accompanied by udder growth.
293. Bacteriological aspects of the manufacture of spray-dried milk and whey powders, including some observations concerning moisture content and solubility
Authors: Crossley E. L. , Johnson W. A. 
Published: June 2009

1. A bacteriological study was made of the commercial operation over a period of 4½ years of two Kestner evaporating and spray-drying plants, handling a fairly good and a very poor milk supply respectively. Processes investigated comprised handling of raw milk, pasteurization, climbing film evaporation, handling of evaporated milk, and spray drying. Data were also obtained showing the influence of variations during processing on the moisture content and solubility of powders. Separated milk, full-cream milk, and whey were handled.2. The general bacterial flora of spray-dried powders and the influence of individual manufacturing processes, packing and storage were studied and possible control methods suggested. Data showing the extent of both hourly and seasonal variations were also obtained.3. A method of bacteriological analysis is described which gave reasonably good agreement between different workers.4. Examination of 671 powder samples showed a wide variation in individual plate counts from 200 to 19,500,000 per g. The flora on standard milk agar at 37° C. was of a specialized type and comprised comparatively few species. Thermoduric streptococci of the ‘enterococcus’ and ‘viridans’ groups predominated,Str. duransandStr. thermophilusbeing the commonest species; in addition, five species of micrococci, probably non-thermoduric, also occurred commonly. Aerobic spore-forming bacilli and threeAchromobacterspecies were found regularly, but their numbers were not of practical importance. Spore-forming anaerobic bacilli were present in 14% of powder samples, probably in very small numbers, and were most frequent during the winter months.5. Coliform organisms were rarely found in 1 ml. of reconstituted milk, but were isolated from 25% of powder samples when 20 ml. of reconstituted milk was examined; coliforms occurred most frequently during the winter months. False positives due to anaerobes were common, especially in stored powders, and confirmatory tests of presumptive positives were essential. Examination of 198 coliform strains from powders and 164 strains from raw milk showed thatcolitypes occurred less frequently in the powders, whilstaerogenes-cloacaetypes, particularlycloacae, were more frequent. 48·5% of the powder strains were heat resistant, as compared with 2·2% of the raw-milk strains. It was shown that the coliform flora of powder was partly due to plant contamination by heat-resistant strains, although some non-heat-resistant strains could survive spray drying. It seemed possible that coli types were less resistant to drying thanaerogenes-cloacae.
304. The gas-packing and storage of milk powder
Authors: Lea C. H. , Moran T. , Smith J. A. B. 
Published: June 2009

The following summary of the effect of increasing quantities of oxygen in producing ‘off’ flavour in gas-packed full-cream milk powder during storage for long periods has been based on observations made in the present series of experiments, supplemented to some extent by results from later work on the gas storage of spray-dried powder which is not here reported in detail.(a) Full-cream powders stored in the presence of up to 0.01 ml. of oxygen per g. of powder kept very well at both normal and high temperatures. This figure corresponds to 1 % of oxygen (after completion of desorption) in the free-space gas of a can of spraydried powder packed to a bulk density of 0.55 g./ml., or to 0.5 % of oxygen in a can of roller powder packed to a bulk density of 0.35 g./ml. Tallowiness was never definitely detected under such conditions, and there seems to be little or no advantage to be gained, at least so far as palatability is concerned, by improving on this figure. An atmosphere containing not more than 0.01 ml. of oxygen per g. of powder can therefore be considered an ideal pack for milk powder.
343. Studies of the Biological Value of the Proteins (Nitrogen) of Dried Skim Milk: Value As An Addition to Bread; Tests With Young and Olderrats; Effects of Storage
Authors: Henry Kathleen M. , Rowland S. J. 
Published: June 2009

1. A sample of roller-dried skim-milk powder, found to possess the very low biological value of 55.2, supplemented slightly but definitely the proteins of national wheatmeal bread when it supplied 23% of the total nitrogen. No such effect was observed with another sample of milk with a biological value of 71.1 when it supplied 17 % of the total nitrogen, or with a further sample of milk with a biological value of 81.3 when added to bread at a 6 % level supplying about 15 % of the total nitrogen. On the first two occasions the biological value for two different samples of national wheatmeal bread was 48.9 and 55.0 respectively for young rats; for the same rats when mature the values were 55.8 and 64.6. No differences attributable to age were found with milk. Baking did not affect the biological value of the proteins of the milk added to the flour.2. The biological value of a sample of spray.dried skim milk declined from a value of 88.5, observed 18 months after manufacture, to 71.1 some 36 months later. The true digestibility remained unchanged.3. Commercial samples of spray.dried and roller.dried skim milk of good quality, and of over.neutralized and overheated roller.dried skim milk, yielded biological values of 78.6, 80.9, 78.2 and 76.2 respectively and true digestibilities of 90.5, 90.1, 89.4 and 88.8 respectively.
344. A Note on Certain Vitamins of Sow's Colostrum
Authors: Braude R. 
Published: June 2009

1. Eighteen samples of colostrum obtained from Large White sows during parturition were examined for total solids, fat, vitamin A, vitamin B^ riboflavin and vitamin C.2. The mean values and ranges for the total solids (fourteen samples) and fat (fifteen samples) were 23.9% (20.6–27.2%) and 3.4% (1.7–5.8%) respectively.3. The mean vitamin A content of eighteen samples was 247 i.u./100 ml. with a range of 103.462 i.u./lOO ml., or 89 i.u./g. fat with a range of 42–137 i.u./g. fat. No β-.carotene was detected in any of the samples.4. The mean vitamin B1 content of seventeen samples was 145 /µg./100 ml. with a range of 81.260 µg./100 ml.5. The mean riboflavin content of sixteen samples was 45.6 µg./100 ml. with a range of 21–78 µg./100 ml.6. The mean ascorbic acid content of seventeen samples was 23.8 mg./100ml. with a range of 12–36 mg./100 ml.
361. Reactions of Jersey calves to hot atmospheres
Authors: Riek R. F. , Lee Douglas H. K. 
Published: June 2009

Four grade Jersey calves were exposed for 7 hr. twice a week to each of several atmospheres having dry-bulb temperatures ranging from 85 to 110° F. and absolute humidities ranging from 6 to 16 gr./cu.ft. The following reactions were studied: rectal temperature; pulse rate; respiratory rate; respiratory volume; evaporative loss; calcium, phosphate, sugar and erythrocyte composition of the blood; behaviour.Rectal temperatures rose rapidly to a higher level than was shown by cows under similar conditions, but maintained a steady equilibrium thereafter, except under the most severe conditions.Respiratory rate responses resembled those of rectal temperature, the difference from those of cows being even more striking.Humidity had relatively less effect upon the rectal temperature and respiratory rate responses of calves than of cows.Pulse rate and tidal respiratory volumes were relatively unaffected, but minute respiratory volumes rose.Evaporative loss per unit body weight resembled that of cows, except that humidity again had less effect. Pulmonary ventilation was inadequate to account for the observed losses.Behavioural changes resembled those of the cows but weakness of the hind limbs was observed at rectal temperatures above 106° F. Blood calcium, phosphate, sugar and erythrocyte levels were not essentially affected.Possible explanations for the lower thermal tolerance of calves, as compared with cows, are considered.
367. Bacterial growth in reconstituted spray-dried milk
Authors: Higginbottom Constance 
Published: June 2009

1. Over 200 samples of spray-dried milks from eight British plants have been examined for total and spore counts, numbers of β-haemolytic colonies and for moulds, yeasts and conliform bacteria.2. The mean count and standard deviation range for total and spore count are reported. No β-haemolytic colonies other than those due to spore-forming bacilli were detected.3. After ageing the reconstituted milk for 24 hr. at 15–5° C. the mean count (37° C.) was unchanged; at 22° C. the increase was 2000-fold and at 37° C. the milk had clotted within this time.4. The predominating organisms in a random selection of the reconstituted milks are described, both for the fresh milk and after ageing at 15·5 and 22° C. A marked increase i n spore-forming bacilli was noted at 22° C.5. The relation of the flora of reconstituted milk to its food-poisoning potentialities is briefly discussed.
369. Determination of the free amino-nitrogen of casein and of fresh and deteriorated milk protein by the Van Slyke method
Authors: Lea C. H. 
Published: June 2009

The reaction of casein and of fresh and deteriorated milk protein with nitrous acid has been followed at constant temperature for 4 hr. in the manometric apparatus of Van Slyke, and simplified procedures suggested whereby the method can be utilized for investigation of the deterioration of the protein of separated milk powder during storage.Technical assistance in this work was given by Mr L. J. Parr: The work was carried out as part of the programme of the Food Investigation Board of the Department of Scientific and Industrial Research.
388. The colorimetric determination of lactic acid in milk and milk products
Authors: Davidson J. 
Published: June 2009

A method is described for the colorimetric determination of lactic acid in milk and unsweetened milk products. The protein and lactose is removed after precipitation with copper sulphate and calcium hydroxide at 45° C, the lactic acid in an aliquot of the filtrate is oxidized to acetaldehyde in sulphuric acid in the presence of copper sulphate, a purple colour is developed withp–hydroxydiphenyl, and the colour intensity is measured in a photoelectric absorptiometer or other suitable instrument.Recoveries of from 96 to 103%, averaging 100%, were obtained when 20–400 mg. lactic acid/100 ml. were added to fresh milk.The proposed method has an advantage over existing methods in the ease and speed with which large numbers of determinations can be carried out simultaneously whilst retaining the essential accuracy.
410. The oxidation of ascorbic acid in dairy products
Authors: Allan J. E. 
Published: June 2009

1. The determination of ascorbic acid in butter by the usual macrotitration method was found to be impossible because this substance rapidly became oxidized while the butter was being melted, so that only about half could be recovered.2. A simple micro-titration procedure enabled more reliable results to be obtained, but the loss of ascorbic acid from smaller samples could not be reduced below about 10% under the most favourable conditions.3. Kinetic experiments have been carried out on butter serum and buttermilk to which ascorbic acid had been added, and from the results it has been deduced that the oxidation of ascorbic acid takes place by three distinct concomitant reactions: one catalysed by the original copper, one catalysed by added copper, and one catalysed by added ferric iron.4. It has been calculated that in an unsalted butter of normal metallic content half the ascorbic acid would be oxidized in about 12 hr. at cold storage temperature ( – 13° C). At this temperature, 0·1 p.p.m. of added copper is about twenty times as effective a catalyst as 1·0 p.p.m. of added iron. At room temperature the corresponding half-oxidation time would be about 2 hr., and here 0·1 p.p.m. of added copper is about four times as active as 1·0 p.p.m. of added iron. In salted butter the inhibitory effect of the chloride ion would increase these times somewhat.5. The chemical state in which copper and iron exist in milk and related products has been discussed, especially in relation to the kinetic results obtained.
435. Keeping quality and raw-milk grading: II. The effect of storage on the results of keeping quality and dye tests
Authors: Eddison R. T. , Kempthorne O. , Hosking Zena , Barkworth H. , Cox C. P. , Rowlands A. 
Published: June 2009

1. The experiments described in this part of the report were designed to obtain information about the effect of time and temperature of pre-test storage on test results and, in particular, about the possibility of a practical method of compensating test results to eliminate or minimize their dependence on the time and temperature of pre-test storage.2. Four separate experiments were planned and carried out in three widely separated areas in England and Wales. Samples of morning milk, brought to the laboratory with the minimum of delay, were divided into a series of subsamples which were subsequently stored at controlled temperatures ranging from 3 to 24°C, and at shade atmospheric temperature, for periods ranging from 7 to 30 hr. before examination by one or more of the following tests: keeping quality at 18, 22 and 24° C. using clot-on-boiling (C.O.B.), and precipitation with 68% alcohol (A.P.T.) or 50% alcohol; methylene-blue test at 37–5° C. and at 18, 22 or 24° C. The results for the different tests were the times to end-point after transfer from the storage to the incubation baths.
439. The rate of creaming of raw cows' and buffaloes' milk
Authors: Fahmi A. H. 
Published: June 2009

A preliminary investigation was carried out on the effects of two ranges of temperature (room and refrigerator) on the creaming properties of cows' and buffaloes' milk. The results reported show that:(1) While refrigerator temperature favoured the creaming of cows' milk, it greatly retarded the creaming of buffaloes' milk. This retarding effect was associated with a smaller cream-layer volume and a greater percentage of fat in the skim milk.(2) At room temperature, the creaming of buffaloes' milk proceeded much more rapidly, suggesting that fat clumping was probably being induced.(3) For both kinds of milk, when creamed at room temperature, the maximum values of the cream-layer volume and the specific cream-volume were found to be less than when creaming occurred in the refrigerator: reverse temperature relationships were observed in connexion with the maximum fat content of the skim milks.In conclusion, it may be added that the observed variations in the cream-layer volume, and the fat content of the skim milks resulting from creaming at the two different temperature levels and for the varying lengths of time, would clearly result in some variability in any cheese made from such milk. This would particularly affect the yield, quality, composition and nutritive value of the cheese.