bluuebunny/crossref_metadata_2025 huggingface dataset:
36. Cheese-Ripening Studies: Nitrogen Distribution in Kingston Cheese-Ripening
Authors: Eagles Blythe A. , Sadler Wilfrid
Published: June 2009

A study has been made of the nitrogen distribution in Kingston cheese, over a ripening period of 98 days. For the determinations, methods evolved and employed by Orla-Jensen, Barthel and others have been drawn upon. In addition, a departure has been made in applying to this study the method developed by Wasteneys and Borsook for the fractional analysis of incomplete protein hydrolysates.

Determinations were carried out on cheese of the same “make” from the day of making to the 98th day of ripening at intervals denned and recorded in the tables and figures.

Results obtained when employing the methods of Orla-Jensen and of Barthel have been complemented by the application of the Wasteneys and Borsook method, which defines the nature and the amount of various protein decomposition fractions (proteose, peptone and sub-peptone) formed as the ripening of the cheese proceeds.

Particularly striking is the finding that the difference in the results of the amide nitrogen determinations and the amino nitrogen determinations can be explained when interpreted in the light of data secured by the application of the method of Wasteneys and Borsook. The amide nitrogen curve has been found to coincide with the sub-peptone nitrogen curve, and the amino nitrogen curve to superimpose itself upon the curve depicting the sum of the subpeptone nitrogen and the peptone nitrogen.

The results of our study, subject to qualification as further data on the nature of specific enzymes may appear, suggest that after the first few hours of ripening the proteolytic breakdown in the ripening of Kingston cheese is of an associative peptic-tryptic-like nature.
41. Breeding for Milk Production in the Tropics
Authors: Edwards J.
Published: June 2009

A Fresh milk supply is as essential in the tropics as it is in the more temperate regions of the world. The most fundamental of the many problems connected with tropical dairying is that concerned with the establishment of breeds of dairy cattle which will live and thrive in their environment, and produce milk; the intensity of the problem varies with the degree of severity of the climatic and environmental conditions. The manner in which this problem has been dealt with at the Government Stock Farms at Kingston, Jamaica, together with the results, is discussed in the following study. The data were collected by Mr J. Hammond from the records of the herds at these farms. To Mr H. H. Cousins, the Director of Agriculture, who has not only built up the herd to its present state of excellence but has kept also a complete record of the pedigrees and performances of all the animals, and to Dr S. Lockett, Veterinary Officer for the Department, our thanks are due for having put these records at our disposal and for communicating to us the results of their experience.
45. The Ayrshire Breed of Cattle: A Genetic Study
Authors: Fowler Alexander Burn
Published: June 2009

1. A study has been made of the degree of inbreeding in the Ayrshire breed of cattle.

2. The coefficient of inbreeding for the whole breed, as calculated by Wright's “Approximate (or Short) Method,” showed a progressive increase from nil in 1877 to a mean value of 5·3 in 1927.

3. No difference was found in the coefficient of inbreeding as between registered bulls and cows.

4. A large proportion of the inbreeding was traced to two foundation sires, Burnhouses (8) and Hover-a-Blink of Drumjoan (892).

5. Using Wright's “Long Method,” it was found that high milk-yielding cows showed a markedly lower coefficient of inbreeding than the breed average. On the other hand, when the coefficient of inbreeding of high milk-yielding cows (over 1000 gallons) was compared with that of cows giving average yields (under 800 gallons) it appeared that inbreeding itself had no detrimental effect on milk yield.

6. In 1923, 39 per cent, of the inbreeding ties of high milk-yielding cows were traced to the Drumjoan herd, as against the next highest herd which had only 6·37 per cent, of ties. Of the total coefficient of inbreeding the Drumjoan herd was responsible for 18·36 per cent., whereas the next highest herd was only responsible for 8·35 per cent. The 1928 results also demonstrated the marked influence of the Drumjoan herd. Practically 50 percent, of these ties were traced to animals related to the foundation sire, Hover-a-Blink of Drumjoan. These results demonstrate the profound influence which one herd, and indeed one bull, may exert in the genetic construction of a recently established breed.

7. It is pointed out that Wright's “Long Method,” when applied to breeds of relatively recent origin, gives far more reliable results than his “Short Method.”
48. Investigations on the Milk of a Typical Herd of Shorthorn Cows. I
Authors: Golding J. , Mackintosh J. , Mattick E. C. V.
Published: June 2009

An investigation of the milk of a typical herd of Shorthorn cows kept under south of England conditions has been carried out.

The results of the first three years of the investigation are now recorded. The plan of the experiment, the history of the cows during the period, the management, feeding, milking, and milk yields are described and illustrated in Tables I and II.
Phosphorus Compounds of Milk. V. The Phosphorus Partition in Milk, with Preliminary Observations on Milk Phosphatase
Authors: Graham W. R. , Kay H. D.
Published: June 2009

1. Using the method described by Sanders for protein and fat precipitation from cow's milk, a fairly satisfactory method of determining the phosphorus partition in cow's milk has been devised.

2. It is found that the gravimetric procedure of the American Association of Official Agricultural Chemists ((10), p. 3), which was not, in any case, specifically recommended for the analysis of milk, cannot be applied with safety to the determination of inorganic phosphate in filtrates prepared by Sanders' (1932) method, and that the conclusion that there is no appreciable amount of organically combined phosphorus in these filtrates is therefore invalidated.

3. The ester P (organically combined, acid-soluble P) in milk obtained by the usual milking routine varies from 1/7 to 1/4 of the inorganic P of the milk (from 7 to 21 mg. P per 100 c.c. milk).

4. An active phosphatase is present in cow's milky, and brings about changes in the ester P content of the milk on standing, possibly within and certainly without the mammary gland. Like phosphatases of all mammalian tissues, its optimumpH is in the neighbourhood of 9·0. In freshly drawn milk it is working, therefore, considerably on the acid side of its optimum.

5. The phosphoric ester P of the milk appears to vary with the breed of cow, being low in the miiy of Canadian Holstein-Friesian cows and higher in that of Jersey cows.
81. Variations in the Solids-not-fat Content of Milk. III. The Lactation Yield and Factors Affecting it
Authors: Bartlett S.
Published: June 2009

1. The influence of the age of cows on the milk yield and on the milk solids is traced. The milk yield reaches a maximum at about the sixth lactation and then declines. The concentration of fat and solids-not-fat shows a gradual decline from the first lactation onwards.

2. During lactations in which the yield is below the normal productivity of a cow, the quality of the milk also tends to be subnormal.
85. Non-pathogenic Haemolytic Streptococci Occurring in Milk
Authors: Minett F. C. , Stableforth A. W.
Published: June 2009

A description is given of the characters of certain streptococci which in small numbers are sometimes found in the milk of individual cows. Although the organisms possessed high haemolytic activity, they showed no evidence of pathogenic power, either for the cow's udder or for ordinary small laboratory animals. Not only are they different from the streptococci of bovine mastitis, but they are also to be distinguished from streptococci of theStr. pyogenesgroup which are occasionally found in milk. One of their principal characters is the formation on solid media of minute colonies, consisting of relatively minute cocci, which grow in broth as very short chains.

The fifty-eight strains studied could be divided into two groups on biochemical grounds: (a) those fermenting glucose and lactose with production of small amounts of acid, (b) those which ferment mannite and salicin as well. The former are referred to as “low-acid” strains and the latter asStr. infrequens, as they bear a resemblance to the organism given this name in Holman's classification. Fermentation of sorbite and trehalose occurred with streptococci of both groups.

The two groups could be distinguished fromStr. pyogenesand the ordinary mastitisStreptococcusby direct agglutination. For distinguishing the two groups from each other, agglutinin absorption methods were required. It was then found that the low-acidStreptococcuspossessed two antigens of which one only was represented inStr. infrequens.
90. Investigations on the Milk of a Typical Herd of Shorthorn Cows. II
Authors: Golding J. , Mackintosh J. , Mattick E. C. V.
Published: June 2009

This paper contains the results obtained in the fourth and fifth, years of a study of the milk of a typical herd of healthy Shorthorn cows. The period of drought in the summer of 1933 is included and furnishes analyses which differ so much from the four previous years that the daily figures are given in Chart 1. In the earlier paper (i) weekly averages only could be published. The greatest seasonal variations which have been demonstrated by the daily analyses are:

(1) A fall of the percentage of fat in the morning's milk in the spring when the cows were on young grass. This was clearly shown in each of the five years.

(2) A fall in the percentage of solids-not-fat in the evening's and morning's milk during the period of drought in 1933, to an extent which had not previously been recorded.

The causes of these changes in the composition of milk will be further studied using the milk of individual cows.

The weekly analyses of morning's milk have also shown seasonal variations.

Relatively high values of the titratable acidity, formol titration, ash, calcium and phosphorus were observed from October 1931 to February 1932, followed by a general decrease in the summer months, while in the late autumn somewhat higher values were again found.

During the summer and early autumn of 1933 values which were lower than any previously obtained during this investigation were recorded for formol titration and for phosphorus, while the time of coagulation with rennet was longer.

Preliminary consideration of the data has revealed the possibility that the fall in non-fatty solids may be particularly associated with the phosphorus content.
126. Note on the Sulphydryl Compounds of Milk
Authors: Jackson Christopher James
Published: June 2009

No sulphydryl compound in free solution could be found in cow's milk. It is suggested that the positive nitroprusside test obtained in milk treated with sodium cyanide is traceable to the cystine in the protein complex.
128. The Determination of Lactose and Glucose in Milk
Authors: Jones Tudor Stanley George
Published: June 2009

1. The application of the method of Somogyi to the determination of the reducing sugar in milk, with a precision of ± 0·36 per cent., is described.

2. Washed yeast does not ferment lactose and does not add reducing material to tungstic acid nitrates.

3. The reducing substance in milk removable by yeast can be determined with an accuracy of ± 3 per cent.
139. A Comparison between Blood Meal and Wheat Gluten as a Supplement to a Low-Protein Diet for Dairy Cows
Authors: Bartlett S.
Published: June 2009

1. A ration for dairy cows which supplied less protein than the recognized protein standards for milk production and contained less lysine than most rations normally used in English farming practice was selected. A comparison was then made between cows receiving this ration supplemented with (a) wheat gluten, a lysine-poor protein, and (b) blood meal, a lysine-rich protein. The addition of blood meal produced no measurable effect on the milk yields, but there was a small and almost significant advantage in the live weights of the cows.

2. In a subsidiary experiment a large increase in the dietary protein produced a very small and non-significant increase in milk yield.
148. Diacetyl in cold-stored butters. II
Authors: Barnicoat C. R.
Published: June 2009

1. Acetylmethylcarbinol in cream is partly destroyed by neutralization and pasteurization, but the diacetyl content is practically unchanged.

2. Diacetyl and carbinol are retained in butter with the butter-milk fraction.

3. Diacetyl is present in butter: (a) sweet-cream 0·05 p.p.m., (b) “mild starter” 0·3–0·4 p.p.m., and (c) “high acid” 1·5 p.p.m. The diacetyl content remains fairly constant during 3½ months' storage at 14° F.

4. Diacetyl in butter does not affect the keeping quality or vitamin A content.

5. The diacetyl content tends to increase when butter is held at 40° F. for several days after manufacture. The change is not caused by oxidation with air, but is probably due to dehydrogenase activity of the “starter” organisms or their enzymes.

6. Experiments with butter “starters” are described.
154. Studies in Cheddar cheese. V. The effect of chemical substances on the ripening process
Authors: Davies W. L. , Davis J. G. , Dearden D. V. , Mattick A. T. R.
Published: June 2009

A number of chemical substances that might be expected, or have been claimed, to affect the rate of chemical ripening have been incorporated in cheese at “salting”. The effect in most cases has been insignificant. It would appear that cheese is a remarkably stable system, the chief factors in the rate of chemical ripening being the concentration of rennet, salt and free water. The importance of the interrelationship between the last two factors has been discussed.
155. The composition of mare's milk. II. The variation in composition during lactation. III. The influence of intra-mammary pressure on the composition of milk with special reference to the mare and cow
Authors: Linton R. G.
Published: June 2009

1. The investigation was for the purpose of ascertaining the cause of the variations previously noted by the author as occurring in mare's milk.

2. Determinations have been made of the composition of the milk of eight Shetland ponies and one Clydesdale mare throughout the lactation period, with observations on the milk of numerous thoroughbred mares. The constituents estimated were the total solids, solids-not-fat, protein, fat, lactose, total ash, CaO, P2O5, and chlorine. The CaO, P2O5and chlorine percentages in the ash of the milk were also determined. The freezing-point and pH were recorded in a number of samples. The animals were kept under natural conditions at grass.

3. It was found that as lactation advanced the percentage of total solids, lactose and fat of the milk increased in a linear manner, whereas the percentage of solids-not-fat, protein, CaO, and P2O5decreased linearly.

4. The regression of the total solids and the chlorine was parabolic in character as also was that of the chlorine-lactose index.
157. The creaming power of heated milk. The relationship between the denaturation of albumin and globulin and the reduction in creaming power
Authors: Rowland Samuel J.
Published: June 2009

1. The effect of heating on the creaming power of milk and the role of truly hydrophilic colloids in increasing the creaming power of raw and of heated milk are discussed. The suggestion is made that a proper understanding of changes underlying the reduced creaming power of heated milk has been handicapped by a lack of reliable data on the extent to which the hydrophilic colloid content of milk is reduced by denaturation of albumin and globulin.

2. Information is obtained concerning the relationship between the denaturation of albumin and globulin and the reduction in creaming power from a series of determinations of the amounts of protein denatured, and of the changes in creaming power produced, by heating samples of the same milk for 30 min. at temperatures of 57·5, 60·0, 61·5, 63·0, 65·0, 67·5, 70·0, 74·8 and 80·0° C.
161. Studies in Cheddar cheese. VI. The degradation of milk proteins by lactic acid bacteria isolated from cheese, alone, with sterile rennet and with whole rennet
Authors: Davis J. G. , Davies W. L. , Mattick A. T. R.
Published: June 2009

It has been shown by experiments in milk that the enzymes of commercial rennet in conjunction with the lactic acid bacteria occurring in Cheddar cheese can bring about protein breakdown similar in extent to that found in the ripe cheese as far as the non-protein nitrogen is concerned. The amino nitrogen produced is, however, much less than in cheese. This may be ascribed to the higher pH of cheese as compared with that of the milk cultures, since acidity adversely affects the peptidases present. Attention is drawn to the differences between the conditions.
163. A new method for the determination of butterfat in dairy products
Authors: Golding John
Published: June 2009

As a member of Committees of the Empire Marketing Board and subsequently of the British Standards Institution, the author has had experience in methods of milk testing which has led to the discovery of a simplified test for butterfat, which may be of value in filling some of the gaps in the application of the present known methods.
191. The spreading capacity of butter. I
Authors: Blair G. W. Scott
Published: June 2009

1. The problem of the physical nature of spreading capacity of butter is discussed, and the advantages of methods measuring individual physical properties in absolute units are given.

2. A simple rheometer is described with which the rate of compression of cylinders of butter can be measured. A simple equation for calculating absolute (mean) viscosities from the data obtained with the apparatus is given.

3. Preliminary experiments, in which temperature control was not as exact as might be desired, nevertheless gave an effective measure of hardness. These are quoted to show the applicability of the method, but they also show the extent to which the phenomenon of “false body” occurs when butter is reworked.

4. A preliminary experiment on the work-hardening of butter is described.
196. The influence of various fodder supplements on the production and the nutritive value of winter milk
Authors: Bartlett S. , Cotton A. G. , Henry K. M. , Kon S. K.
Published: June 2009

1. An experiment is described in which comparisons were made between the effect of (a) mangels (control feeding), (b) artificially dried grass, (c) sprouted maize, and (d) kale used as dietary supplements on the production and nutritive properties of the milk of dairy cows.

2. No significant differences were found between any of the foods in their effect on yield of milk, or its content of fat or solids-not-fat.

3. The feeding of kale and of artificially dried grass markedly increased the colour and vitamin A content of the milk, but sprouted maize had no more effect in this respect than mangels.

4. As compared with the feeding of mangels, sprouted maize and artificially dried grass had no measurable effect on the vitamin B complex level of the milk.

5. The vitamin B2 (complex) level was more variable and was lowest in the milk from the sprouted maize cows. It is not known, however, whether the difference was due to the feeding or to differences in the cows themselves.

6.The same statement applies to figures for the vitamin C level which was highest in the sprouted maize milk.

7. The growth-promoting properties of the milks produced on mangels, artificially dried grass and sprouted maize were compared. The milks were fed, supplemented either with minerals alone, or with minerals plus sugar as a source of energy. In one series of experiments the milks were given adlibitum, in another the intake was “equalized.” No differences were found and it is concluded that under English conditions, this technique does not disclose the presence in milk of a new essential factor.
206. Gas production by Bacterium coli and by lactic acid streptococci under different conditions
Authors: Hassouna M. M. , Allen L. A.
Published: June 2009

In a previous paper (Allen (1)) some methods have been described for measuring gas production by micro-organisms. The objects of the work described here were (1) to measure the gas production (if any) by pure strains of lactic acid streptococci and by starters growing in milk; (2) to measure the total gas evolved by Bact. coli in the early stages of growth in different media, particularly milk; (3) to find the effect on gas production by Bact. coli of growing Str. lactis in the same medium with it and to measure the proportion of Str. lactis relative to Bact. coli required to inhibit gas production completely—information which has a bearing on the defects due to coliforms growing in the early stages of cheese making; (4) to find the influence on gas production by Bact. coli, with and without the concomitant growth of Str. lactis, of subjecting it to anaerobic conditions from the outset; and (5) to measure the effect due to the hydrogen alone (by absorbing the carbon dioxide) on the gas produced by Bact. coli under different conditions.
219. The nutritive value of proteins for milk production. V. The effect of high temperature and of season on the nutritive value of grass proteins, the supplementary effect of the maintenance ration on the production ration, and the effect of feeding a high-protein ration
Authors: Morris S. , Ray S. C.
Published: June 2009

1. As regards the nutritive value of artificially dried spring grass, the protein appears to be unaffected by the temperature of drying even to the extent of scorching the grass. Early autumn dried grass has a biological value intermediate between spring and late autumn grass, while linseed cake has a very low value.

2. The supplementary effect of the maintenance on the production ration has been shown when hay was substituted for straw in the maintenance ration together with a production protein intake of poor biological value.

3. With an excess of protein in the ration most of the excess nitrogen was excreted in the urine, while both the milk yield and the biological value of the food protein fell considerably. It is possible that, together with an adequate amount of lysine in the protein ingested, a certain mixture of amino-acids is essential before maximum milk yield can be obtained.

4. A study of the nitrogen metabolism shows that high-temperature drying has no effect, whereas marked effects were noted with the early autumn grass and more especially with the linseed cake. The hippuric acid nitrogen output decreased with the high-temperature dried grass, possibly the effect of a loss on drying of benzoic acid. With the high-protein diet an increased excretion of creatinine was noted with no alteration in the creatinine intake. The purin metabolism varies with the total nitrogen excretion, the allantoin increasing markedly in the high-protein period. This is due to an increased intake of purin base.

5. The sulphur metabolism shows the results to be expected from previous publications except in the case of the high-temperature dried grass. It appears that the high-temperature treatment has in some way affected the nature of the sulphur compounds in the grass, with a consequent diminution in the retention.
220. The nutritional requirements of the lactic acid bacteria
Authors: Davis J. G.
Published: June 2009

1. Sucrose and maltose behaved like dextrose, only more specifically in relation to type, in acclerating the rate of growth of lactic acid bacteria in milk. Sucrose was greatly superior to maltose but was never superior to dextrose.

2. Citrate was without significant effect.

3. The sterilization of yeast and dextrose in the medium produced a medium superior to milk + separately heated yeast and dextrose for Streptococcus III. For other types marked differences were not observed.

4. The plant extracts used were found to fall into the following order of ability to accelerate growth: yeast autolysed for 6 days, malt = beer wort, potato, alfalfa, carrot, tomato, clover, yeast autolysed for 2 days, and bean. Malt and beer wort were superior to yeast for some group III organisms.

5. Malt extract and beer wort contain growth factors for some lactic acid bacteria that are not present, or are present only to a small extent in yeast.

6. Alfalfa and clover appear to contain substances specifically stimulating gas production for group III types, especially the streptococci.

7. Normal variations in the content of vitamins B1 and B2 and co-carboxylase in milk do not appear to affect the rate of growth of starter organisms.
231. The assessment of curd firmness prior to cutting
Authors: Coppen F. M. V.
Published: June 2009

The reproducibility of Scott Blair's method for measuring curd firmness has been tested and measurements of the “firmness” of cheese curds immediately prior to cutting have been made and related to an expert's opinion. Contrary to her beliefs it was found:

(1) that the mean firmness for normal Cheshire and Double Gloucester curds was the same as that for normal Cheddar curds,

(2) that normal curds, regardless of type, were softer in the summer months than in the winter.

Though confident opinions are often expressed on very small differences in firmness, the smallest difference in modulus which can be correctly appreciated appears to be of the order of 8%.
233. The effect of increased iodine feeding upon the iodine content of cows' milk
Authors: Matthews Norman L. , Curtis George M. , Meyer J. H.
Published: June 2009

1. The milk and blood iodine of a herd of thirty Guernsey and thirty Holstein cows has been determined, previous to and during prolonged increased iodine feeding to one-half of the herd. The increased amount of iodine was fed as potassium iodide which was mixed uniformly with a grain feed.

2. The blood iodine of the iodized cows was greatly and uniformly increased.

3. The milk iodine was increased. This increase was principally dependent on the amount of iodine which was fed. During late spring, however, the milk iodine from both the iodized and control cows was unusually low. During early autumn the milk iodine from the iodized cows was low.

4. The milk from the iodized cows contained 7–26 times as much iodine as that from the control cows. An average milk iodine of 80μg. % was obtained from the iodized cows throughout a mid-year period of 5 months.

5. This experiment reveals that a milk of increased iodine content can be readily produced by increased iodine feeding.
247. The problem of variations in the growth-promoting value of milk for rats
Authors: Bartlett S. , Henry K. M. , Kon S. K.
Published: June 2009

1. Three Shorthorn cows were grazed on the best available permanent pasture when the growth of grass was vigorous, and three other cows of similar lactational history continued to be stall-fed. At the time of the experiment they had been on winter rations for 6 months.

2. By suitable blending of morning and evening milkings the fat content of the milk from both groups of cows was adjusted daily to a common level. A part of each milk was then holder-pasteurized.

3. Four groups of specially prepared litter-mate male rats were fedad lib., for a period of 8 weeks, on raw and pasteurized milks, both being supplemented with minerals. There were no differences in appetite or gain in weight.

4. In similar experiments sugar was added to the milks to double their caloric value. Again the growth and appetite of the animals were the same on the raw summer and “winter” milks. Pasteurization did not alter significantly the value of the milks, but the summer milk, whether raw or pasteurized, was superior to the pasteurized “winter” milk.

5. Guinea-pigs receiving the raw mineralized milks alone or with sugar died within a comparatively short time. There was no difference in growth performance or time of survival between the summer and “winter” milk groups.

6. These experiments give no indication of the presence of a specific new appetite or growth factor in pasture milk.
253. The measurement and significance ofpH values in cheesemaking
Authors: Davis J. G. , Thiel C. C.
Published: June 2009

1. The application of the colorimetric dilution method for the determination ofpH values in cheesemaking is discussed and the necessary precautions for accuracy described.

2. Bromthymol blue is recommended for milk and whey ofpH. > 5·8 and the B.D.H. 4460 indicator for whey of pH < 5·8.

3. Titratable acidities andpH values each afford an incomplete picture of the working of a curd. Together they afford a valuable indication of the normality or otherwise of the making process.

4. The buffer value of whey rises steadily during manufacture. ThepH rises abruptly after salting, although the titratable acidity continues to increase.

5. The buffer value of whey is controlled chiefly by the rate of working but tends to be lower with pasteurized milk.

6. A diagrammatic method for summarizing the “behaviour of a vat” and for detecting abnormal working is described.
265. On the use of various sera for the determination of the soluble calcium and phosphorus of milk
Authors: Pyne G. T.
Published: June 2009

A comparison of the value of various milk sera for the determination of the soluble phosphate and calcium of milk, using dialysis at 0–5° C. as a standard method, gave the following results:

(i) Rennet whey was the most satisfactory; with fresh milk it yields fairly accurate values for calcium, slightly low (average 5 %) for phosphate. With increasing acidity of the milk both sets of values tend to rise somewhat relatively to those of the dialysate, phosphate approaching the true value and calcium rising slightly above it.

(ii) Mercuric chloride borax serum gives high results for the soluble phosphate of fresh milk With increasing acidity of the milk, the results fall steadily.

(iii) Papain whey gives somewhat low results for both the phosphate and calcium of raw and pasteurized milk, with the same tendency as rennet whey to yield higher and improved results as the acidity of the milk: increases. With boiled milk it gives abnormally high results for both constituents. The additional phosphate and calcium appear to arise from the solution of colloidal calcium phosphate.
266. The influence of “mastitis” upon the yield and quality of Cheddar cheese
Authors: Johns C. K. , Hicks T. J. , Gibson C. A.
Published: June 2009

Milk of normal appearance from cows having a latent infection with Str. agalactiae yielded definitely less cheese than that from normal cows. Milk from cows free from “agalactiae” infection, yet classed as “abnormal”, behaved similarly. The lowered yield appeared to result from the lower casein and solids-not-fat contents of these “mastitis” milks.

With a single exception, the cheese made from these “mastitis” milks were not inferior in quality to those made from normal milks.
296. The effect of varying pitching point and rate of scald on the physical properties and general quality of cheese made from milk of varying acidity and from pasteurized milk
Authors: Blair G. W. Scott , Coppen F. M. V. , Dearden D. V.
Published: June 2009

1. Following the experiences gained from an earlier experiment, cheese were made at varying controlled pitching points and rates of scald, the experiment being done both with sweet milk and comparatively acid milk.

2. One of the two cheese made from each vat was submitted to physical tests at regular intervals during the ripening process and the other cheese, when ripe, were judged by a panel of experts who also, together with non-experts and routine analysts, gave judgements of firmness and ‘spring’.

3. Tables were drawn up in which the rank orders of the cheese for each objective physical test and subjective judgement are compared with one another.

4. With the possible exception of vapour pressure and ‘spring’, the effect of pitching consistency was much more marked than that of the differences in rate of scald although the latter were considerable. Many physical properties were well correlated with pitching consistency.

5. The cheese makers are shown to have a greater self-consistency as individuals in picking out replicates and as a group in their decisions as to the rank order, by comparison with the other categories.
The influence of abnormal (‘non-acid’) milk on cheese starter cultures
Authors: Hunter G. J. E. , Whitehead H. R.
Published: June 2009

If milk containing the inhibitory substance produced by growth of ‘non-acid’ streptococci is used for the propagation of starter, it can cause delayed coagulation, simulating a starter failure caused by bacteriophage. ‘Non-acid’ milk in the starter culture milk affects cultures differently according to the particular strains of streptococci present; some strains are considerably less inhibited than others.
312. The persistence and recovery of bacteriophage in cheese
Authors: Nichols Agnes A. , Wolf J. Z.
Published: June 2009

Several cheese made from milk after the starter had failed, or during outbreaks of ‘slowness’ at three different places, were found to contain bacteriophage, which it is now possible to isolate from cheese where the whey is no longer available. The concentration of phage in cheese was found to be fairly constant when tested periodically during one year. The significance of such persistence on phage dispersal, its reintroduction into the dairy, and carry-over from one season to the next is pointed out.
331. The effect of feeding shark-liver oil to cows on the yield and composition, and on the vitamin A and carotene content of the milk
Authors: Blaxter K. L. , Kon S. K. , Thompson S. Y.
Published: June 2009

1. An experiment with ten dairy cows has shown that the daily feeding of 30 or 60 g. of shark-liver oil containing 80,000 i.u. of vitamin A/g. is without effect on milk yield, fat yield, the fat and solids-not-fat percentage of the milk and on the health and wellbeing of the cow.

2. The concentration of aneurin, riboflavin and vitamin C in the milk was not affected by the feeding of shark-liver oil.

3. The total carotenoids of the milk fat decreased when shark-liver oil was fed. The vitamin A content of the fat increased 1100% when 30 g. were given and 1850% when 60 g. were fed. The highest individual value reached was 390 i.u./g. fat.
334. A simple agar medium for the growth of lactic streptococci: the role of phosphate in the medium
Authors: Hunter G. J. E.
Published: June 2009

A cheap, easily prepared and relatively uniform agar medium, containing beef extract, lactose, peptone, yeast extract and phosphate, is described. It gives excellent results with lactic streptococci and a good growth with many other organisms.

The role of phosphate and agar in the medium and the effect of filtration is discussed. It is suggested that the value of phosphate is due partly to its buffering effect and partly to its combination with some constituent of agar to form a substance which has a growth-promoting action on the lactic acid bacteria. This active substance is largely removed from the medium if filtration through paper pulp is practised.
350. The effect of sodium chloride on thepH values of milk and of butter serum
Authors: Hills G. Loftus
Published: June 2009

The addition of 10% of sodium chloride to milk caused an average drop inpH of 0·42 unit. Different workers have found very variable relations between thepH of cream and thepH of salted butter churned from it. When 10% of sodium chloride is added to 0·2% solutions of sodium citrate or sodium phosphate there is a drop inpH of the order of 1 unit. When an alkaline solid phase is present as in the serum of neutralized cream and butter, and in milk, this change inpH may be diminished or reversed, possibly by increased solubility of the alkaline precipitate in sodium chloride solution. Factors are listed which will cause thepH of salted butter to differ from that of the cream from which it was made. In the churning of alkaline creams there occurs in the butter an increase in the proportion to the serum water of calcium phosphate and of other solids-not-fat.
376. Experiments on milking technique: 3. Combined effect of reducing the milking time and washing the udder with hot water: 4. Effect of increasing the milking time
Authors: Dodd F. H. , Foot A. S.
Published: June 2009

1. An experiment is reported in which the influence of washing the udder with hot and cold water and of reducing the milking time to 60% of the normal flow period (interval between putting on teat cups till main flow ceased) was studied over a period of 9 weeks in twenty cows.

2. The temperature of the udder washing water had no measurable effect on output of milk or speed of milking. The reduction in milking time failed to increase rate of milk flow and resulted in a fall in milk yield.

3. An experiment with ten cows is reported in which the teat cups were, for periods of 6 weeks, left on at each milking twice as long as was necessary to carry out a normal milking.

Neither the yield and quality of milk nor the rate of milking were affected.
381. A rapid and simple phosphatase test for milk
Authors: Aschaffenburg R. , Mullen J. E. C.
Published: June 2009

A simple and rapid phosphatase test is described which is based on the use ofp–nitrophenylphosphate as the substrate. Execution of the test requires few and easy operations: incubation of the milk at 37° C. with a buffered solution of the substrate, followed directly by a visual comparison of the intensity of yellow colour of liberatedp–nitrophenol with that of boiled-milk standards containing known amounts ofp–nitrophenol. The test permits the detection of minor processing faults with an incubation time of only 30 min. In this form it should prove of value in creamery control. A more searching, but equally simple test is obtained by increasing the period of incubation to 2 hr.
392. Seasonal variations in the sales of calves in different parts of Great Britain, 1943–1947
Authors: Phillips R. , Brown E. H. , Davies J. L.
Published: June 2009

The records of calf sales to the Ministry of Food have been examined for the years 1943–7 and maps made to show variations in (a) the percentage disposal of the annual calf crop, and (b) the percentage autumn calf sales, in different parts of Great Britain. These have enabled the intensive dairying areas and the extensive rearing areas to be denned.

It is postulated that the variations in the seasonality of calf sales in different areas may be influenced by factors other than husbandry, and that climate may have both direct and indirect effects upon the development of winter oestrus in cattle.
398. The properties of New Zealand butters and butterfats: II. The relation of hardness of New Zealand commercial butter to composition of the butterfat
Authors: Dolby R. M.
Published: June 2009

Determinations of hardness were made on 324 samples of butter drawn monthly for 3 years from nine factories distributed throughout New Zealand. The results were compared by statistical methods with the iodine values and softening points of the corresponding butterfats which had been determined by Cox & McDowall(4). It was shown that the softness (reciprocal of hardness) was significantly correlated with both iodine value and softening point, which together explained 55 % of the variation in softness observed. Of the remaining variation, 59% was due to seasonal changes other than those in iodine value and softening point and 36 % to differences between factories. It is considered that manufacturing variations were responsible for very little of the seasonal variations, and that the differences between factories were due as much to district differences as to manufacturing differences. It is concluded that only a small part of the variation in softness of the butter samples was due to manufacturing variations, and that at least 80 % of the variation could be attributed to differences in the raw material.
427. The acid phosphatase of cows' milk: I. Some properties of the enzyme
Authors: Mullen J. E. C.
Published: June 2009

1. The acid phosphatase content of milk is reasonably constant from quarter to quarter in normal uninfected cows.

2. The acid phosphatase content of milk from infected quarters is enhanced in comparison with the uninfected quarters. The differences found were from 4·1 to over 50 enzyme units per 100 ml. milk.

3. It has been shown that a Streptococcus agalactiae suspension is capable of hydrolysing phenylphosphate at pH 4–1, and it is suggested that this organism is largely responsible for the enhanced enzyme content of the milk from the infected udder.
433. The design and use of a milking machine for sows
Authors: Smith D. M. , Whittleston W. G. , Allen J.
Published: June 2009

In the course of an investigation on the yield and composition of sows' milk, we have experienced difficulties in obtaining representative samples of milk for analysis.

The technique adopted was that described by Braude et al. (1) in which 5 units of pitocin were injected into the ear vein of the sow and the milk withdrawn by hand. Since the yield of these sows was being measured over a 24 hr. period each week, it was possible to compare the quantities obtained, following injection, with the average amount suckled by the litters during natural sucklings. The comparison was never particularly accurate as we found that two operators, each milking one teat, were all that could be conveniently accommodated on each side of the sow. This meant that only four glands could be milked properly. We found, too, that variations in teat size and mammary gland size affected the speed of withdrawal and the final amount obtained.
440. Determination of lactose in dairy products
Authors: Babad J. , Grunpeter A.
Published: June 2009

The necessity for a rapid and easy micro-method for the determination of lactose in dairy products arose during our work. The procedure for glucose determination in blood was adopted and modified for dairy products. Quantities of 1–10 mg. lactose can be estimated rapidly. Comparison with the macro-method of Lehman gave satisfactory results.
453. Nutritive value for rats of sow's milk in comparison with cow's milk
Authors: Braude R. , Henry K. M. , Kon S. K. , Mitchell K. G.
Published: June 2009

1. Four experiments with 108 rats to compare the nutritive value of sow's milk and cow's milk are described. In Exps. 1–3 the milks were fed on a comparable basis of caloric value.

2. In the first experiment, in which the milk intake was equalized, rats receiving diluted sow's milk grew at a significantly faster rate and utilized their calorie intake more efficiently than rats receiving cow's milk.

3. In the second experiment, again with equalized milk intake, rats receiving sow's milk utilized their calorie intake significantly more efficiently than rats receiving diluted evaporated cow's milk.

4. In the third experiment in which the milks were given without stint, rats receiving diluted sow's milk either with or without the addition of a synthetic vitamin supplement, grew at a faster rate, and utilized their calorie intake significantly more efficiently than rats receiving cow's milk either with or without the same vitamin supplement. The vitamin supplement did not improve the nutritive value of either milk.

5. In the fourth experiment the biological value of the proteins in freeze-dried sow's milk (85·1) proved significantly lower than in freeze-dried cow's milk (90·1).
464. A simple method for the routine determination of lactose in milk
Authors: Francis F. J. , Smith M. Doreen
Published: June 2009

A method for the determination of lactose in milk based on clarification with dialysed iron and oxidation of the filtrate with alkaline ferricyanide solution, followed by titration with sulphato-ceric acid, is proposed. It is simple, rapid and well adapted to the routine estimation of lactose in milk or to the determination of small quantities of lactose. The conditions of the reactions and comparison of results with other methods are discussed.
487. Studies on the origin of oxidized flavour in whole milk
Authors: Pont E. G.
Published: June 2009

With 1·0 p.p.m. of added copper, well-defined oxidized flavours described as cardboard, oily and metallic developed in pasteurized whole milk after ·2–3 days' storage at 3° C. With 0°1 p.p.m. copper only slight and irregular off-flavours, usually described as cardboard, appeared. Partial oxidation of the ascorbic acid of the milk with H2O2did not increase its susceptibility to oxidized flavour development.

Marked off-flavours were always associated with peroxide values in the milk fat of 0·2 and more (m.equiv. oxygen/kg.) determined by the ferric thiocyanate technique. With fat peroxide values of about 0·5, usually obtained after 6–7 days at 3° C. with 1·0 p.p.m. copper, the oxidized flavour was very strong and the milk usually undrinkable.
524. The influence of feeding tocopherol to dairy cows on the yield of milk and milk-fat and on the tocopherol content and keeping quality of the butter
Authors: Nielsen Jens , Fisker Anders N. , Pedersen Aage H. , Prange Inge , Søndergaard Ebbe , Dam Henrik
Published: June 2009

Supplementation of a typical Danish winter ration with 2 g. of DL-α-tocopherol acetate per cow per day did not result in an increased yield of milk or milk-fat. The keeping quality of the butter was practically uninfluenced or possibly slightly reduced by the supplementation. The supplementation caused a rise in the tocopherol content of the butter from 10 to 12µg./g. in the unsupplemented group to 23–26/µg./g. in the supplemented group. After the experimental period the amount of total tocopherol in the butter decreased rapidly. It increased again when the cows went to pasture.

Butter-fat obtained from the unsupplemented group with 9·6–13·2µg. tocopherol/g. and from the supplemented group with 27·3–31·2µg. tocopherol/g. did not produce encephalomalacia in chicks when incorporated at a level of 30% instead of lard in a suitable test diet, but the amount of tocopherol present, especially in the butter-fat from the unsupplemented group, was not sufficient to prevent white striation of breast muscles in chicks under the same conditions.
526. A study of variation in twin cattle: I. General description
Authors: Donald H. P.
Published: June 2009

A general preliminary description is given of a uniformity trial with twin cattle, the object of which was to study sources of variation within pairs by comparing one-egg and two-egg twins with pairs of contemporary half-sibs. Problems relating to equality of treatment and accuracy of diagnosis are discussed.
Section B. Bacteriology and mycology applied to dairying
Authors: Hiscox E. R. , Briggs C. A. E.
Published: June 2009

It is now some 6 years since the appearance in this series of a Review of Bacteriology and Mycology applied to Dairying (1) with sections on milk control, detergents and disinfectants, and pasteurization. Nearly 12 years have elapsed since a complete Review (2) including all the sections listed above was published in theJournal of Dairy Research; some attempt has been made to deal with the more important work going back to these Reviews.
530. The relative feeding value for milk production of two National Cattle Foods
Authors: Bailey G. L. , Broster W. H. , Brown B. B. , Foot A. S.
Published: June 2009

A feeding trial of the relative value for milk production of National Cattle Food No. 1 and National Cattle Food No. 6 is reported; forty-two first calvers were employed.

The two foods were shown to be of very similar feeding value for heifers giving two to four gallons daily, the difference between them being slightly in favour of the N.C.F. 1. Each pound of this food produced 0·109 lb. more milk than the same amount of N.C.F. 6, but this difference was statistically without significance.