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The Relationship Of Acetylmethylcarbinol And Diacetyl To Butter Cultures, M. B. Michaelian, R. S. Farmer, B. W. Hammer 2017 Iowa State College

The Relationship Of Acetylmethylcarbinol And Diacetyl To Butter Cultures, M. B. Michaelian, R. S. Farmer, B. W. Hammer

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The value of selected cultures of bacteria for the development of a desirable flavor and aroma in butter has been thoroughly established through comparisons of butter made with and without culture and also through the extensive commercial use of cultures. There are two distinct types of organisms present in the butter cultures commonly used, one of which (Streptococcus lactis or, according to certain investigators, Streptococcus cremoris) attacks primarily the lactose with the formation of large amounts of lactic acid while the other type (Streptococcus citrovorus and Streptococcus paracitrovorus Hammer (4), or Betacoccus Cremoris Knudsen and Sorensen (11), or Leuconostoc dextranicus ...


Normal Growth In Dairy Cattle, D. L. Espe, C. Y. Cannon, E. N. Hansen 2017 Iowa State College

Normal Growth In Dairy Cattle, D. L. Espe, C. Y. Cannon, E. N. Hansen

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Male calves of all the breeds studied weighed more at birth than female calves. The birth weights of female calves were as follows: Holsteins, 89 pounds; Guernseys, 65 pounds; Ayrshires, 63 pounds; and Jerseys, 50 pounds.

There was considerable variation among individuals in their live weights. Coefficients of variation ranged from above 15 percent in calves to less than 10 percent in 2-year old heifers.

The data show that the time of first freshening marks the greatest change in the rate of growth in live weight.

Very little difference can be observed in the relative rates at which animals of ...


Length And Floor Construction Of Dairy Stalls, Henry Giese, C. Y. Cannon 2017 Iowa State College

Length And Floor Construction Of Dairy Stalls, Henry Giese, C. Y. Cannon

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

One of the problems confronting the designer of a dairy barn is to determine the proper length of the stall platform. Cows vary considerably in length, and the stall length should vary to to meet the requirements of individual cows. Stalls that are too short make uncomfortable beds, force the cows to stand with one or both hind feet in the gutter and cause them, in reaching for hay in the manger, to carry manure to the stall floor. Long stalls are equally objectionable as the droppings fall on the platform rather than in the gutter. Adjustable stanchions are available ...


Studies On The Development Of Butter Cultures From Mixtures Of Organisms, R. S. Farmer, B. W. Hammer 2017 Iowa State College

Studies On The Development Of Butter Cultures From Mixtures Of Organisms, R. S. Farmer, B. W. Hammer

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Studies on the bacteriology of butter cultures have shown that two types of bacteria are normally present, one which attacks primarily the lactose with the formation of large amounts of lactic acid, while the other is characterized by its production of volatile acid from citric acid. These findings suggest the development of butter cultures under carefully controlled conditions by making mixtures of the two types of organisms. While many satisfactory butter cultures have been secured with this procedure, mixtures made with organisms that appear typical on the basis of morphology, cultural characteristics and the usual biochemical tests, often fail to ...


Bacteriology Of Butter Iv. Bacteriological Studies On Surface Taint Butter, H. A. Derby, B. W. Hammer 2017 Iowa State College

Bacteriology Of Butter Iv. Bacteriological Studies On Surface Taint Butter, H. A. Derby, B. W. Hammer

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

1. The surface taint butter examined often contained large numbers of bacteria, as determined by the plate method, and with some of the samples the counts were very high; with a few samples the counts were comparatively low. The counts were higher on the surface portion of a sample than on the interior portion in all but 1 of 20 comparisons.

2. The surface taint butter examined usually contained large numbers of yeasts, with the surface portion of a sample commonly containing a larger number than the interior portion; the butter showed some mold counts that were high and a ...


Chemistry Of Butter And Butter Making I. A Comparison Of Four Methods For The Analysis Of Butter With An Explanation Of A Discrepancy Found To Exist In The Fat Determinations, E. W. Bird, D. F. Breazeale 2017 Iowa State College

Chemistry Of Butter And Butter Making I. A Comparison Of Four Methods For The Analysis Of Butter With An Explanation Of A Discrepancy Found To Exist In The Fat Determinations, E. W. Bird, D. F. Breazeale

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

1. A modification of the A. O. A. C. method for complete butter analysis is described. The method is considered applicable for use in control laboratories, in which eight or more samples are analyzed at a time.

2. This method, together with the Kohman and Mojonnier analyses for butter, was compared with the A. O. A. C. method as a standard. The modified official and the Kohman methods check closely with the A. O. A. C. method for all constituents of butter. With the 50 samples analyzed in duplicate the fat content was 0.22 percent lower by the Mojonnier ...


Bacteriology Of Butter Iii. A Method For Studying The Contamination From Churns, B. W. Hammer, H. C. Olson 2017 Iowa State College

Bacteriology Of Butter Iii. A Method For Studying The Contamination From Churns, B. W. Hammer, H. C. Olson

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

A method for the study of the contamination from churns is suggested. It consists of allowing a small amount of an agar medium containing 2.5 percent air-dried agar to solidify in contact with the surface to be studied, the transferring of the agar preparation thus formed to a sterile petri dish and finally the counting of the colonies that develop on incubation. With surfaces nearly horizontal the agar is poured on, while with surfaces not nearly horizontal the medium is poured behind a glass plate held a short distance from the surface by a gasket. The results are expressed ...


Bacteriology Of Butter Ii. A Method For The Microscopic Examination Of Butter, B. W. Hammer, J. A. Nelson 2017 Iowa State College

Bacteriology Of Butter Ii. A Method For The Microscopic Examination Of Butter, B. W. Hammer, J. A. Nelson

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Routine determinations of the numbers of bacteria in market milk, market cream and ice cream are being used extensively in the control of the quality of these products. Comparable determinations are only occasionally employed with butter. One of the reasons for this is that many butter plants regularly add enormous numbers of bacteria in the form of butter culture to the cream that is to be churned, and, while a large percentage of these organisms is carried away in the buttermilk, the bacterial content of the butter is nevertheless greatly increased. The addition of butter culture in order to give ...


Supplements To A Milk Diet For Dairy Calves, C. Y. Cannon 2017 Iowa State College

Supplements To A Milk Diet For Dairy Calves, C. Y. Cannon

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The two factors probably responsible for the inability to raise calves on a ration of whole milk alone are the development of rickets and anemia. Tetanic convulsions in calves probably arise in association with rickets. None of the calves in the experiments reported in this bulletin developed tetany as they were protected against rickets by feeding cod-liver oil and bone meal.

Blood pictures of the calves on a milk diet disclosed an anemic condition as measured by a reduced quantity of hemoglobin, a subnormal erythrocyte count and a lower specific gravity of the blood. The calves also became dyspneic, showed ...


Bacteriology Of Butter I. Influence Of The Distribution Of The Non-Fatty Constituents On The Changes In Bacterial Content During Holding, B. W. Hammer, R. V. Hussong 2017 Iowa State College

Bacteriology Of Butter I. Influence Of The Distribution Of The Non-Fatty Constituents On The Changes In Bacterial Content During Holding, B. W. Hammer, R. V. Hussong

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

1. Unsalted butter held at 21°C. showed a rapid increase in the number of bacteria it contained, whether it was held in the normal physical condition or with the serum largely separated. In general, the multiplication of bacteria was much more rapid when the serum was separated than when it was not.

2. Unsalted butter held at 7°C. also showed an increase in the number of bacteria contained, whether it was held in the normal physical condition or with the serum largely separated, but the increase was much less rapid than at 21°C. The multiplication was, in ...


Proteolysis By Streptococcus Lactis With Special Reference To Butter Cultures And Butter, B. W. Hammer, V. H. Patil 2017 Iowa State College

Proteolysis By Streptococcus Lactis With Special Reference To Butter Cultures And Butter, B. W. Hammer, V. H. Patil

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

1. Certain cultures of S. lactis definitely proteolyzed milk while others did not.

2. Proteolysis by S. lactis did not require extended incubation periods but was evident even in as short a time as one and one-half days without the addition of CaCO3 to the milk.

3. Proteolysis was evident in freshly coagulated butter cultures grown in pasteurized or sterilized milk.

4. With both S. lac tis and butter cultures, proteolysis was more pronounced on extended holding when CaC03 was added to the milk than when it was not.

5. The organisms associated with S. lactis in butter ...


The Influence Of Temperatures And Certain Other Factors Upon The Percentage Of Fat In Milk, Earl Weaver, C. A. Matthews 2017 Iowa State College

The Influence Of Temperatures And Certain Other Factors Upon The Percentage Of Fat In Milk, Earl Weaver, C. A. Matthews

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The percentage of fat in cows' milk varied definitely with seasonal changes. The fat test was highest during the first half of winter, or January. It gradually declined to the second half of summer, August and early September, when the lowest test occurred, and then it rose rather rapidly in the fall.

Ayrshire and Holstein tests were approximately 0.6 percent lower in the second half of summer than in the first half of winter. Guernsey and Jersey tests were approximately 1.1 percent lower.

The butterfat tests were found to be lower with higher outside and inside temperatures.

As ...


Studies On Starters, B. W. Hammer, M. P. Baker 2017 Iowa State College

Studies On Starters, B. W. Hammer, M. P. Baker

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

For a number of years the dairy section of the Iowa Agricultural Experiment Station has devoted considerable effort to an investigation of starters. This has seemed advisable because good starters have been shown to be very helpful in improving the quality of butter, which is the important dairy product of the state.


J. C. Penney: The Man, The Store And American Agriculture (Under Contract), David Delbert Kruger 2017 University of Wyoming

J. C. Penney: The Man, The Store And American Agriculture (Under Contract), David Delbert Kruger

David Delbert Kruger

No abstract provided.


Classification Of The Streptococcus Lactis Group, B. W. Hammer, M. P. Baker 2017 Iowa State College

Classification Of The Streptococcus Lactis Group, B. W. Hammer, M. P. Baker

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

'l'he lactic acid producing streptococci show certain differences, some of which must be of importance from the standpoint of the growth of these organisms in dairy products. A classification of this group of organisms has been proposed; it is not presumed to be complete and other types will necessarily be added. The classification is as follows:

Typical S. lactis

Malty S. Iactis—S. lactis var. maltigenes

Ropy S. lactis—S. lactis var. hollandicus

Slow reducing S. lactis—S. lactis var. anoxyphilus

Slow coagulating S. lactis—S. lactis var. tardus

Heat resistant lactic acid streptococci—S. thermophilus


Influence Of Carbon Dioxide Upon Quality And Keeping Properties Of Butter And Ice Cream, F. F. Sherwood, F. G. Martin 2017 Iowa State College

Influence Of Carbon Dioxide Upon Quality And Keeping Properties Of Butter And Ice Cream, F. F. Sherwood, F. G. Martin

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

1. Carbon dioxide did not improve the quality of butter, but showed a tendency to lower the score of the butter.

2. The composition of the butter was not influenced by carbon dioxide.

3. The rate of oxidation in carbonated butter was as great as that in the uncarbonated product.

4. Carbon dioxide had no affect on the bacteria in carbonated butter.

5. No results were obtained to show that carbon dioxide improves the quality of ice cream.

6. The texture of ice cream was not influenced by the carbonating process.

7. The application of carbon dioxide to ice cream ...


Influence Of The Milk On The Starter Made From It, M. P. Baker, B. W. Hammer 2017 Iowa State College

Influence Of The Milk On The Starter Made From It, M. P. Baker, B. W. Hammer

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Altho the types of bacteria present is a very important consideration in the preparation of starters, the medium in which the organisms are to grow is also important. Normal milk, either whole or skimmed, is apparently the most satisfactory material as well as the most widely used. Milk reconstituted from mill} powder or condensed milk, and normal milk handled in various Ways by diluting and adding such fermentable substances as lactose and glucose have been employed for the making of starters\ but have not come into general usE and do not seem to yield as desirable a product as normal ...


Citric Acid Content Of Milk, F. F. Sherwood, B. W. Hammer 2017 Iowa State College

Citric Acid Content Of Milk, F. F. Sherwood, B. W. Hammer

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The citric acid which is normally present in milk and cream can be fermented by a number of organisms commonly present in· dairy products. Some of these, such as the citric acid positive colon-aerogenes organisms, are always objectionable in milk and its derivatives, while others, Streptococcus citrovorus and S. paracitrovorus, which are frequently associated with S. lactis, are important in the development of flavor and aroma in starter and in butter, and undoubtedly in other materials.


Part I—Influence On Starters And Of Air Air Supply, Temperature Of Incubation, And Rates Of Ripening, P. Toens, B. W. Hammer 2017 Iowa State College

Part I—Influence On Starters And Of Air Air Supply, Temperature Of Incubation, And Rates Of Ripening, P. Toens, B. W. Hammer

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Altho starters made with selected cultures have been used for many years, their satisfactory preparation in quantities still remains one of the big problems of the butter-making industry. Data recently reported have proven that starters contain at least two organisms instead of only the common acid producing type, Streptococcus lactis, and while this information has shown that it is necessary to keep a proper balance between the organisms and has indicated the reason for some of the unsatisfactory results in the carrying of starters, it has not provided methods that enable the butter manufacturer to prepare uniformly good starters. The ...


Studies On Streptococcus Paracitrovorus Group, B. W. Hammer, M. P. Baker 2017 Iowa State College

Studies On Streptococcus Paracitrovorus Group, B. W. Hammer, M. P. Baker

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

A study of 124 cultures of S. paracitrovorus from milk, cream and butter confirms the characterization of the group as those streptococci that produce a definite but variable increase in the acidity of milk and a high volatile acidity, which is greatly increased by the adding of citric acid to the milk to be fermented.

Organisms having the same general appearance in litmus milk as S. paracitrovorus. US but which fail to give a high volatile acidity or to show an increased volatile acidity when citric acid is added to the milk are readily isolated from dairy products. Cultures of ...


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