Dairy Science Commons^™

Rapid Acid Tests For Cream, E. W. Bird, D. F. Breazeale

Bulletin (Iowa Agricultural Experiment Station)

The Farrington rapid acid test has been employed for many years by the fluid milk industry for grading samples on the borderline of acidity set for their purchase. In performing the test, neutralizing solutions (containing phenolphthalein) used are of such strength that 1 dipper of solution added to 1 dipper (of the same size) of milk gives a pink mixture if the milk is 0.1 percent acid or less; 2 dippers of neutralizing solution grade at the 0.2 percent point and so on. By adjusting the neutralizing strength the grades corresponding to 1 and 2 dippers of neutralizing ...

Tests For Cream Sediment, E. W. Bird, D. F. Breazeale, H. P. Guest

Bulletin (Iowa Agricultural Experiment Station)

Commercial milk plants have employed the sediment test for milk for many years. In fact, the milk sediment test has its place on the milk score card. The amount of sediment is always determined in scoring milk. The test is extremely simple; it consists of passing 1 pint of milk through a sediment tester and catching the sediment present in the milk on a circular pad 1 inch in diameter.

The application of a sediment test to cream, on the other hand, has been attempted only very recently. A test as simple as that for milk is impossible. The cream ...

Iowa Blue Cheese, E. F. Goss, V. Nielsen, M. Mortensen

Bulletin (Iowa Agricultural Experiment Station)

Iowa is an importer of cheese. In 1933 Iowa dairy plants manufactured 1,491,822 pounds of cheese.2 In the same year consumption is estimated to have been 10,254,397 pounds, using the 1933 United States Department of Agriculture figure of 4.15 pounds per capita and 1930 Iowa census figures as a basis of computation. In 1933 Iowa dairy plants produced 14.6 percent of the cheese consumed in the state. If this percentage could be greatly increased it would result in a larger and more diversified market for Iowa milk.

Production of cured cheese in Iowa ...

The Agar Disc Method For Studying The Contamination From Metal Surfaces, H. C. Olsen, B. W. Hammer

Bulletin (Iowa Agricultural Experiment Station)

A procedure, designated the agar disc method, has been developed at the Iowa Agricultural Experiment Station² for the study of the contamination from churns. It consists of allowing a small amount of a special agar medium to solidify in contact with the surface to be studied, the transferring of the disc thus formed to a sterile petri dish and, finally, the counting of the colonies that develop on incubation. The usefulness of the method for the examination of churns, especially when the churns are at some distance from the laboratory³, suggests its application to the study of the ...

The Use Of Water Bowls In The Dairy Barn, C. Y. Cannon, E. N. Hansen, James R. O'Neal

Bulletin (Iowa Agricultural Experiment Station)

1. Dairy cows, watered by means of water bowls, drank approximately 18 percent more water and yielded 3.5 percent more milk and 10.7 percent more butterfat than cows that were watered twice per day at an outside tank.

2. Cows watered with water bowls drank an average of about 10 times in each 24 hours. Approximately two-thirds of the water was consumed in the daytime, that is between 5 a. m. and 5 p. m., and the other one-third at night.

3. Cows watered at the outside tank frequently drank but once per day. This occurred about 30 ...

The Effect Of Processing, Handling And Of Testing Procedures On The Fat Content Of Ice Cream, E. W. Bird, Elgin A. Johnson

Bulletin (Iowa Agricultural Experiment Station)

A number of inquiries received from Iowa ice cream manufacturers shows that they believe that some steps in the processing or handling of ice cream cause a lower fat percentage in the frozen product than in the mix. From a theoretical viewpoint, no such fat lowering should occur in the product. A sufficient number of inquiries has been received, however, to warrant studying the causes of any irregularities which might result from the processing and the handling of the mix and of the frozen ice cream, and likewise, any winch might be introduced by the methods of obtaining and mixing ...

The Pasteurization Efficiencies Secured With Milk From Individual Farms, R. V. Hussong, B. W. Hammer

Bulletin (Iowa Agricultural Experiment Station)

The pasteurized milk coming from certain of the Iowa market milk plants contains larger numbers of bacteria than would be expected from the numbers present in the raw milk. These large numbers are sometimes due to contamination following pasteurization, but comparatively high counts are also encountered with carefully pasteurized milk taken directly from the pasteurizer so that there is no opportunity for contamination from the cooler, bottler, etc.

In order to determine whether or not certain milk supplies contain comparatively large percentages of heat resistant organisms, the pasteurization efficiencies¹ secured with milk coming from different farms were studied. The ...

Observations On The Counting Of Bacteria In Ice Cream By The Plate Method, N. E. Fabricius, B. W. Hammer

Bulletin (Iowa Agricultural Experiment Station)

The development of official or standard methods for various types of laboratory examinations represents a distinct advance from the standpoint of the usefulness of the results obtained. The standard methods for the bacteriological analysis of milk have made it possible to compare, on a satisfactory basis, the results secured in different laboratories and, undoubtedly, have been a factor in extending the use of bacterial counts for the control of milk supplies. The procedure at present required by Standard Methods of Milk Analysis¹ for the macroscopic colony count on milk has been developed over a period of years. It is ...

Creamery Organization And Construction, Henry Giese, M. Mortensen

Bulletin (Iowa Agricultural Experiment Station)

Since 1910 the Iowa Agricultural Experiment Station has taken an active part in assisting the farmers in the organization and erection of creameries.

The early creameries planned by the Iowa station in cooperation with the various creamery organizations were satisfactory at that time. Emphasis was placed primarily on sanitation, convenience, durability and economy in construction. These factors are not ignored today but are rather more strongly emphasized . In addition, much emphasis is placed on the appearance of the building, since the creamery of today is often centrally located in the town and is one of the important business institutions of ...

A Simple Linebreeding Program For Poultry Breeders, C. W. Knox

Bulletin (Iowa Agricultural Experiment Station)

It is practically impossible to increase egg production beyond a certain point in any flock of chickens without proper regard to mating and breeding. The old adage that it is impossible to squeeze blood out of a turnip also holds true in poultry keeping for, no matter how much care is given the birds, they cannot lay eggs beyond their HEREDITARY capacity.

As with egg production, hatchability, egg size and body weight cannot be increased beyond certain limits unless some constructive breeding program is followed. Altho this bulletin will deal with linebreeding for higher egg production, the same principles will ...

Influence Of Environment And Breeding In Increasing Dairy Production-Iii, Earl Weaver, C. A. Matthews, H. H. Kildee

Bulletin (Iowa Agricultural Experiment Station)

The constant growth of the dairy industry constitutes a notable phase in the history of American agriculture. That the industry will continue to grow is beyond question. The wider knowledge of the food value of dairy products, the increasing demands in America for intensive and economical production, to which demands dairying is especially adapted, and the more general recognition of . the financial possibilities that lie in dairy farming all attest the view that the greatest development of the industry is yet to be realized.

Good dairy cows are indisputably the foundation upon which this development will depend and what is ...

The Economy And Efficiency Of A Milking Machine, Charles A. Matthews, John M. Shaw, Earl Weaver

Bulletin (Iowa Agricultural Experiment Station)

Industry has progressed considerably in substituting mechanical appliances for hand labor, thereby vastly reducing unit production costs. In more recent years agriculture has been making wider uses of mechanical equipment with the result that production has been increased, altho the proportion of agricultural laborers has markedly declined. Kinsman¹ states that within the last 75 years a man's ability as a field worker on the farm has been trebled. As the future of agriculture is studied it seems likely that the greatest opportunity for reducing production costs is to increase the output per man thru mechanical equipment. It is ...

Succulent Feeds For Dairy Cows In Summer, H. H. Kildee, Earl Weaver, John M. Shaw, Fordyce Ely

Bulletin (Iowa Agricultural Experiment Station)

Profits in dairy operations are determined largely by the roughages available on a dairy farm. Successful dairymen plan feeding practices according to the roughages they have at hand. The kind and amount of grain they feed depends upon the roughage, being employed largely to supplement any possible deficiency in the roughages.

Factors Which Influence The Yield And Consistency Of Ice Cream, M. Mortensen

Bulletin (Iowa Agricultural Experiment Station)

The pasteurization, aging and homogenization of the cream used, the temperature of the circulating brine and the amount of the mix in the freezer all have an influence upon the yield and texture of ice cream. In some instances that influence is marked and has much to do with successful results in ice cream manufacture.

Just what influence these various factors exert was determined in a series of tests made by the author at the Iowa Agricultural Experiment station. The results of these tests are presented in this bulletin for the information of ice cream manufacturers. The bulletin also presents ...

Bacteria In Ice Cream---Ii, B. W. Hammer, E. F. Goss

Bulletin (Iowa Agricultural Experiment Station)

The work done in various laboratories during the last 10 to 15 years has clearly established that the ice cream ordinarily offered tor sale contains large and frequently enormous numbers of bacteria. As a result, certain health departments have begun to consider the sanitary as well as the chemical condition of the ice cream sold within their districts and have established various regulations intended to prevent the sale of a product that may contain organisms liable to set up diseased conditions in the persons consuming it. These regulations are undoubtedly of value and many of them have been of great ...

Influence Of Environment And Breeding In Increasing Dairy Production, H. H. Kildee, A. C. Mccandlish

Bulletin (Iowa Agricultural Experiment Station)

Data secured in an investigation which has now been under way for eight years at the Iowa Agricultural Experiment station give direct support to the belief that a good paying dairy herd can be built up from a foundation of common cows thru proper methods of feeding and management and thru the use of a good purebred dairy sire. The results of this work are presented in a preliminary way in this bulletin and will be given in more complete form when the investigation has been carried further.

Investigations of this kind are fundamental to the task of increasing dairy ...

Studies On The Market Milk Of Iowa, B. W. Hammer, A. J. Hauser

Bulletin (Iowa Agricultural Experiment Station)

A study of market milk conditions in Iowa by the market milk laboratory of the dairy department at Iowa State College reveals the fact that the state has a real milk problem to deal with.

In the cities and towns in which the investigation was carried on, the results indicate these facts:

The milk and cream, whether raw or pasteurized, commonly contains excessive numbers of bacteria, altho samples without excessive numbers were sometimes found.

The presence of large numbers of bacteria in pasteurized milk and cream indicates that the heat exposure used in some plants is too low, altho improper ...

Pasteurization Of Cream For Buttermaking, M. Mortensen, W. G. Gaessler, W. H. Cooper

Bulletin (Iowa Agricultural Experiment Station)

In some European countries the pasteurization of cream for buttermaking is extensively practiced. Butter manufacturers in the United States have long recognized that this is a desirable procedure and they have written numerous letters to the experiment stations seeking information regarding it. In many cases it has been more or less difficult to answer these inquiries because of the comparatively small amount of experimental work which has been done along this line.

The purpose of the experiments herein reported was to determine the value of pasteurization to those engaged in the manufacture of butter. In this connection the effect of ...

The Pasteurization Of Milk In The Final Package, B. W. Hammer, A. J. Hauser

Bulletin (Iowa Agricultural Experiment Station)

In the work reported in this bulletin an effort was made to determine the most favorable vat temperature and time of exposure for final package pasteurization. The only type of cap used was the Dacro cap, although; probably in a general way the results would be applicable also to other packages used for pasteurizing. The points considered in the determination were bacterial efficiency, creaming ability and the heated flavor produced.

High pasteurization temperatures are undesirable because of the reduced creaming ability and marked heated flavor of milk so treated.

Lacto, M. Mortensen, B. W. Hammer

Bulletin (Iowa Agricultural Experiment Station)

Interest in sour milk drinks has become quite general in recent years through the work and teaching of Metchnikoff, who believes that their use will aid materially in prolonging life and delaying the changes incident to old age. However, most people dislike sour milk and will not use it, so several years ago the writer undertook to prepare sour milk drinks so flavored with fruit juices as to make them more palatable. The dairy section of the Iowa Agricultural Experiment station took up these experiments and produced a frozen sour milk product of the consistency of ice cream and possessing ...