bluuebunny/crossref_metadata_2025_split huggingface dataset:
442. Variations in composition of cows' milk during a period of 12 weeks
Authors: Featherstone J. , Rickaby C. D. , Cavell A. J. 
Published: June 2009

The milk from twelve individual cows in a mixed herd in Shropshire was sampled twice weekly over a period of 12 weeks, which covered the transition from winter to summer conditions of feeding. Detailed analytical results are tabulated, and certain figures presented in graphical form. In addition, bulk samples of both morning's and evening's milk were obtained and tested for fat and solids-not-fat.On the whole the results show great individual consistency of composition, but an appreciable rise in the crude protein content of the milk from all cows took place in late April and in May, this effect being attributed to the change-over in feeding to an all-grass diet. From a consideration of the figures obtained, it is deduced that:(1) The average composition of mid-lactation milk may differ markedly from cow to cow, but appears to be unchanged by minor alterations in the winter rations, provided these are reasonably satisfactory to begin with. There is, however, a marked increase in total protein resulting from the introduction of spring-grass feeding.(2) The results show that a herd, although well-fed and efficiently managed, may produce milk in the late winter months, and even in the early spring, which is below the legal standard of 8·50% in s.n.f.
478. Hard cheese made from Egyptian cows' and buffaloes' milks
Authors: El-Sokkary A. M. , Hassan H. A. 
Published: June 2009

1. Hard cheese of Cheddar, Derby and Manfis types was made from cows' milk and from buffaloes' milk. Buffaloes' milk curd of the Derby type was also milled at different acidities.2. Initial acidity was higher and rate of acid development was greater in cows' milk and curd, whilst loss of fat in the whey was lower.3. Cows' milk cheese contained more moisture, more total, soluble, and non-protein nitrogen, but less fat than buffaloes' milk cheese.4. During ripening, the rate of acid development and protein degradation was greater in cows' milk cheese, whilst loss of moisture was usually smaller.5. Buffaloes' milk cheese was inferior in grading quality to cows' milk cheese.6. Attempts to improve the quality of buffaloes' milk cheese were made by altering the Derby cheese-making process as follows:(a) ripening milk longer before renneting;(b) modification of the milk casein/fat ratio;(c) combining (a) and (b);(d) modification of the casein/fat ratio plus scalding of the curd at a lower temperature and for a shorter time.7. The last treatment (d) proved most effective and yielded cheese of very similar chemical composition and grading quality to that obtained from cows' milk.
509. Bacteriological studies on pasteurized milk
Authors: Alexander Hazel , Higginbottom Constance 
Published: June 2009

1. The numbers and species of micro-organisms surviving in commercial high-temperature short-time pasteurized milks sampled direct from the cooling section of the pasteurizer have been determined and compared with those in the corresponding raw milk and in the raw milk after low-temperature pasteurization in the laboratory.2. The geometric mean counts at 37° C. for twenty-five samples of raw, L.T. and H.T.S.T. pasteurized milks were 74,130, 1,740 and 3,200 per ml. respectively. The corresponding figures at 30° C. were 123,030, 7,080 and 8,510 per ml.3. The percentage destruction of the bacteria was slightly smaller at all four plants for the H.T.S.T. pasteurized milks than for the corresponding L.T. pasteurized milks. The mean percentage destruction for the L.T. pasteurized milks was 97·7% for bacteria growing at 37° C. and 94·3% for bacteria growing at 30° C. The corresponding figures for the H.T.S.T. pasteurized milks were 95·9 and 93·1%.
521. Normal variations in the rate of machine milking
Authors: Dodd F. H. 
Published: June 2009

1. A study has been presented of the machine milking rate of 141 cows recorded in 326 lactations.2. The coefficients of variation between cows of various measures of machine milking rate are usually in the range 30–40%, whilst the within-cow variations are of the order of 8–11%.3. The differences between the milking rates of cows in a single herd are given, together with the distribution of these differences.4. Milking rate declines as lactation advances, the decline being greater for fast milking cows.5. Lactation decline in milking rate is related independently to change in milk yield and to interval since calving.
527. A study of variation in twin cattle: II. Fertility
Authors: Donald H. P. , Anderson D. 
Published: June 2009

1. Results from a uniformity trial with fifteen pairs each of one-egg and two-egg twins and pairs of half-sibs are described.2. Intra-pair variance in age at the first observed heat was less for the one-egg than for the other pairs but not significantly so. The slowest growing pairs showed delay in onset of heat.3. 71·8% of the intervals between heats shown by unserved heifers were 17–27 days in length. No genetic variation and no individuality could be detected in either this character or the number of services per conception.4. The variance in the gestation period was less within the one-egg than within the other pairs but not significantly so.
539. The effect of temperature treatment of cream before churning on the consistency of butter
Authors: Dolby R. M. 
Published: June 2009

1. Measurements of hardness and ‘free-oil’ content of samples of butter from cream held at various temperatures before churning were made before and after storage. Hardness was determined by the sectility method, while free-oil content was estimated from the weight of oil exuding from thin slices of butter sandwiched between filter-papers and held at 64–4° F. (18° C).2. Butter from cream held at 60° F. and churned at 45° F. was much softer and contained more free oil than butter from cream held and churned at 45° F.3. If the cream was precooled to 45° F. before being held at 60° F. the butter was very slightly softer than that from cream held at 60° F. without precooling, but the difference disappeared after storage. It contained rather less free oil, but the softening point of the oil was lower. Fat losses in churning which were high where cream was held at 60° F. were reduced almost to normal when cream was precooled before being held at 60° F.4. Cream slowly cooled to 45° F. yielded butter which was softer and contained more free oil than that from cream cooled rapidly to 45° F. and held at that temperature. The butter, however, was not so soft as that from cream held at 60° F.5. Butter from cream held at a temperature below that at which it was to be churned did not differ significantly in hardness or free-oil content from that produced from cream held at the churning temperature.6. Present commercial methods of cream treatment in New Zealand (rapid cooling to churning temperature and holding at that temperature) give butter of almost maximum hardness for the type of fat involved at each stage of the season.7. More uniform consistency of butter throughout the season could be achieved only by reducing the hardness of the firmer butter and not by increasing the firmness of the ofter butter.
557. Studies of the secretion of milk of low fat content by cows on diets low in hay and high in concentrates: IV. The effect of variations in the intake of digestible nutrients
Authors: Balch C. C. , Balch D. A. , Bartlett S. , Johnson V. W. , Rowland S. J. , Turner Jill 
Published: June 2009

1. Digestibility trials were conducted, and the rate of passage of hay was measured, with five Shorthorn cows during a period of normal diet and during two experimental periods in which diets low in hay and high in concentrates were given. In the first experimental period the concentrates were cubes of the wartime type sold as National Cattle Food No. 1, and containing a variety of constituents; in the second they were a mixture offlakedmaize (50%), weatings (35%) and decorticated ground-nut cake (15%). For convenience these are referred to as concentrate ‘cubes’ and ‘mixture’ respectively.2. During the initial and final control periods the cows consumed daily 17–21 lb. hay, and about 4·5 lb. concentrates per 10 lb. of milk produced. In the initial control period the concentrates were the concentrate cubes, and in the final they were the concentrate mixture. The hay was reduced to 4 lb. daily during the two experimental periods and the remainder of the standard requirements of the animals were met by concentrates. The concentrates were the cubes in the first experimental period and the mixture in the second experimental period.3. Seducing the hay to 4 lb. did not affect the fat content of the milk when the other food in the diet was the concentrate cubes, but there was a striking mean fall of 1·04% fat when the cubes were replaced by the concentrate mixture. This represented a loss of over 30% in the yield of fat.4. Digestibility trials, conducted in the initial control and first and second experimental periods, indicated that the fall in milk fat content was not the result of changes in the amounts of dry matter, crude protein, ether extract, crude fibre, cellulose, cellulosans or pentosans not in cellulose digested. The essential difference between the diet of low hay with the concentrate mixture and the other diets given in this experiment was that it provided a high intake of starch yet had little of the physical property of roughage. It is concluded that depression of milk fat content results from a combination of these two factors and probably originates from changes in the physical and biochemical processes of the reticulo-rumen.5. The intake of starch equivalent, as calculated from the intake of digestible nutrients, was close to standard requirements in all periods of the experiments, but there was a surplus of digestible crude protein.6. The mean solids-not-fat content of the milk rose 0·48% at the time of the fall in milk fat, and this was entirely due to an increase in milk protein. After the return to normal diets the recovery of solids-not-fat was slower, but no less complete, than the recovery in milk fat.
558. The secretion of a single tracer dose of labelled iodide in the milk of the lactating cow
Authors: Glascock R. F. 
Published: June 2009

1. A tracer dose of 131I in the form of radioactive potassium iodide of about 50µg. in weight has been administered to a lactating cow and the secretion of the radioactivity in the milk studied.2. The highest activity was found in the milk on the 1st day after dosing and was only slightly lower than that expected if the iodide had been uniformly distributed throughout all the water in the animal's body.3. The secretion of labelled iodine in the milk attained a maximum on the 1st day after dosing and thereafter declined exponentially with a half period of 1·5 days until the 9th day. The rate of secretion, though still approximately exponential, then had a much longer half period (about 10 days) but was too small to study at the dose level used.4. Owing to the decay of the element the observed secretion of radioactivity declined more rapidly than that calculated for labelled iodine and over the first 9 days of the experiment had a half period of approximately 1·2 days. Thereafter the radioactivity declined more slowly with a half period of approximately 3·5 days.5. From these findings it is calculated that regular daily dosing at the same rate would result in an equilibrium level in the milk about 2·3 times the maximum arising from a single dose.6. Less than 5 % of the original dose was recovered from the milk over the period of the experiment by which time the concentration had declined to 0·5 % of its maximum.7. The radioactivity in the milk was found to be in the chemical form of iodide ion.
566. Studies of the secretion of milk of low fat content by cows on diets low in hay and high in concentrates: V. The importance of the type of starch in the concentrates
Authors: Balch C. C. , Balch D. A. , Bartlett S. , Hosking Zena D. , Johnson V. W. , Rowland S. J. , Turner Jill 
Published: June 2009

1. Three comparable groups of cows were used to investigate the effect, on milk composition and yield, of diets consisting of 4 lb. hay daily and concentrates containing 35% weatings, 15% decorticated groundnut cake and 50% of either flaked maize, maize meal or dredge corn (crushed oats and barley) respectively.2. During initial and final control periods all the cows received 16 lb. hay daily and, per 10 lb. of milk produced, they received about 4 lb. of the concentrate mixture containing flaked maize. During the experimental period of 6 weeks all the cows received 4 lb. hay, concentrates according to milk yield, and an extra 7 lb. of concentrates daily. One group of cows received the concentrate mixture containing flaked maize, a second group the mixture with maize meal and the third group that with dredge corn. The mean daily intakes of starch for the different groups were respectively 6·0, 6·4 and 5·8 lb. per cow.3. The diet containing flaked maize caused a marked, and that containing maize meal a small fall in the fat content of the milk, but the diet containing dredge corn was without effect. In the last 2 weeks of experimental treatment the adjusted mean fat percentage for the group of cows receiving flaked maize was 0·51 and 0·71 below the percentages for the groups receiving maize meal and dredge corn respectively. The yields of milk and of milk fat were also lower in the group receiving flaked maize than in either of the other groups, but the experimental treatments produced no changes in the milk solids-not-fat percentage.4. This experiment has shown that when diets low in hay and high in concentrates are given to lactating cows, the type of starch in the concentrates is of great importance in determining the extent of the depression in milk fat percentage. The greater depression with flaked maize than with maize meal or dredge corn is thought to be associated with the effect of the starch on the flora of the reticulo-rumen.
649. The effect of design of teat-cup liners on mastitis incidence
Authors: Dodd F. H. , Oliver J. , Neave F. K. 
Published: June 2009

1. An experiment was carried out to study the effect on udder health and milk yield when half-udders of dairy cows were milked with either a moulded or an extruded teat-cup liner.2. There was a higher incidence of mastitis in quarters that were milked with moulded than with extruded liners, but the incidence of new infection was similar for each group of quarters.3. The types of liners used had no measurable effect on teat orifice erosion or leucocyte content of the milk, nor was the decline in milk yield with advance in lactation significantly different for the groups of quarters.We wish to thank Dr A. T. R. Mattick and Mr A. S. Foot for advice and encouragement, and Miss H. R. Chapman for assistance in the cleaning of teat-cup liners. We are indebted to Miss M. S. Hawkins and Messrs T. M. Higgs and D. S. Simpkin for technical assistance.
684. Factors influencing the vitamin content of milk fat: VII. The possible existence of protein-bound carotenoids and vitamin A alcohol in mammary secretion
Authors: McGillivray W. A. 
Published: June 2009

1. The distribution of carotenoids and vitamin A in milk-fat globules has been further investigated. The results obtained support previous observations that the carotenoid content of the fat obtained by solvent extraction from the smaller globules in milk is greater than in the fat obtained from the larger globules. It has also been shown that the vitamin A alcohol content of the extracted fat varies in the same way as the carotenoid content, but that the reverse appears to be the case for vitamin A ester.2. It is suggested that these differences in concentration are not due to a surface layer of carotenoids and vitamin A alcohol on the fat globule but to the presence in mammary secretions, as in blood, of protein-bound forms of these substances. In support of this it has been shown that when fat is obtained by centrifuging rather than by solvent extraction, its carotenoid and vitamin A content appears to be almost independent of globule size. Furthermore, some vitamin A and carotenoids remained in the virtually fat-free serum obtained from normal milk, colostrum and pre-partum secretion and was precipitated with the various serum proteins, particularly the globulin fraction. The increased carotenoid and vitamin A alcohol content of mastitis milk may also be explained by the presence of abnormally large amounts of these protein-bound forms.The author is grateful to the Department of Scientific and Industrial Research for a grant towards the cost of the investigation; also to the farm staff of The Dairy Research Institute (N.Z.) for assistance with the collection of milk and colostrum samples.
692. The influence of carbon dioxide on the growth of lactic streptococci
Authors: Whitehead H. R. , Jones P. A. , Robertson P. S. 
Published: June 2009

The initial rate of growth ofStr. lactisandStr. cremorisin skim-milk depends upon the proportion of CO2present in solution. When CO2is constantly swept from the milk medium by a stream of CO2-free gas all strains show a very prolonged lag period. They eventually emerge from this lag period after more than 8 hr. and grow well enough to coagulate the milk within 24 hr. For optimal initial growth the lactic streptococci require the presence in solution in the milk of proportions of CO2within the range 0·2 and 2·3% by volume. Some strains have a higher CO2requirement within this range than others. Skim-milk after sterilization contains less than the optimum proportion of CO2for many strains of lactic streptococci.Yeast extract in a proportion of about 0·5% can substitute for CO2in skim-milk.The periodic inversion of cultures in plain skim-milk reduces the initial rate of growth of some of the streptococci, particularly those which form long chains. The reason for this is unknown. It does not occur when yeast extract is present.
699. Lactobacilli in Cheddar cheese: 1. The use of selective media for isolation and of serological typing for identification
Authors: Naylor Jill , Sharpe M. Elisabeth 
Published: June 2009

A comparison of three different media, yeast dextrose agar, tomato dextrose agar and acetate agar (which is selective for lactobacilli) showed that the acetate medium was satisfactory for the isolation and counting of lactobacilli from Cheddar cheese during ripening. Lactobacilli were isolated on this medium in the early stages of ripening when the large numbers of starter streptococci growing on the other media were completely suppressed. Lactobacilli isolated were identified biochemically and serologically. Serological typing was found to be a useful method of identifying large numbers of isolates and of assessing the incidence and distribution of particular types in the cheese.We wish to thank Dr A. T. R. Mattick for his interest and helpful advice in this work; Dr L. A. Mabbitt for preparation of the cheese samples; Miss H. R. Chapman for making the experimental cheese; and Mrs P. Jarrett for technical assistance.
700. Factors influencing the activity of cheese starters. The role of milk peroxidase
Authors: Wright R. C. , Tramer J. 
Published: June 2009

1. Certain starter cultures have been found to be inhibited in the presence of milk peroxidase.2. A high correlation has been established between the inactivation of milk peroxidase and of the inhibitory action by use of critical values of any of the following: temperature, pH, concentration of either sodium azide or hydrogen peroxide.3. The inhibitory action can be overcome by the addition of certain reducing substances such as cysteine and sodium hydrosulphite.4. The inhibitory action is exhibited by the corresponding separated milk and whey.5. It is suggested that this inhibition may be due to the formation of a specific inhibitory oxidation product having a quinonoid structure.6. The addition of 1–2% of pasteurized milk or whey to autoclaved milk caused total inhibition, whereas such additions to milk heated to 190° F. showed no such effect. This is attributed to the presence of SH groups in the latter milk capable of reducing the oxidation product.7. It is suggested that the inhibition due to peroxidase is identical with that ascribed to lactenin 2, and that the inhibition described in our previous paper as due to ‘agglutinin’ is identical with that ascribed to lactenin 1.
719. Observations by fluorescence microscopy of casein in milk, curd and cheese
Authors: King N. 
Published: June 2009

Fluorescence microscopy was applied to the examination of casein in milk, curd and cheese, to check or support the picture obtained by electron microscopy. The best fluorochroming effect was shown by thioflavine T, acridine orange, coriphosphine and basic fuchsin.In milk, larger casein particles (0·1–0·8 μ in diameter) were rendered visible as minute nearly spherical corpuscles in lively Brownian movement. The sediment obtained on centrifuging the whole milk at about 900 g contained predominantly large particles (average diameter 0·;8 μ). On acid or rennet coagulation the casein particles aggregated to flocs, which finally formed a three-dimensional framework.From curd or cheese freezing-microtome sections (10 μ thick) were examined. The curds which did not possess the fibrous (‘chicken-breast’) texture, characteristic for wellcheddared curd, under the fluorescence microscope displayed a granular structure, whereas curds with a pronounced fibrous texture showed a network of thin micro-fibres, particularly in sections cut along the direction of macro-fibres.The sections (10 μ or less thick) of curd and cheese on the surface of water slowly spread out. The spreading was accompanied either by conversion of the form of casein from granular into fibrous, or by stretching of the micro-fibres in the already existing network.The grain boundaries in curd and cheese (Cheddar, Emmental, Edam) were almost free of fat. No grain boundaries existed in process cheese.
723. The effect of level of concentrate feeding and type of roughage on milk production
Authors: Castle M. E. , Maclusky D. S. , Waite R. , Watson J. N. 
Published: June 2009

1. In a short-term winter feeding trial using eight Ayrshire cows, a concentrate with a nominal starch equivalent of 68 was fed at 2 lb. and 4 lb./gal. of milk with either 16 lb. hay or 16 lb. dried grass. Silage (40 lb. per day) was also fed.2. The weight of dry matter from grass products eaten per day was similar on all four treatments. Differences in total daily dry-matter consumption were very largely attributable to differences in the consumption of concentrate dry matter.3. The daily dry-matter consumption as a percentage of live weight increased from 2·5 on the rations that included hay and 2 lb. concentrates per gal. to 3·2 on the rations that included dried grass and 4 lb. concentrates per gal.4. Milk yield was significantly increased from an average of 33·5 to 37·3 lb./day when the amount of concentrates fed increased from 2 to 4 lb./gal. and also significantly increased from 33·9 to 36·9 lb./day when dried grass was fed in place of hay.5. There was an increase of 0·9 lb. milk for each 1 lb. increase of starch equivalent plus 0·2 lb. digestible crude protein intake as a result of either increasing the rate of concentrate feeding, or of feeding dried grass instead of hay.6. The fat content of the milk was similar on all four rations, whereas the solids-not-fat varied from 8·42% on the ration that included hay +2 lb. concentrates/gal, to 8·59% on the ration that included dried grass +4 1b. concentrates/gal. This change in S.N.F. was almost entirely in the protein fraction of the milk.7. There was a gradation in live-weight change from -0·74 lb./day on the hay +2 lb. concentrates/gal, to +0·34 lb./day on the dried grass +4 lb. concentrates/gal.8. After a consideration of profit margins, milk quality and live-weight changes it was concluded that both treatments B (dried grass +2 lb./gal.) and C (hay +4 lb./gal.) gave optimum and almost identical results.