Agrégateur de flux

Interpretive Summaries, December 2017

Journal of Dairy Science -

Invited review: Sustainable forage and grain crop production for the US dairy industry. By Martin et al., page 9479. There are multiple threats to the sustainability of feed production for the US dairy industry, and these are being magnified by climate change. In the coming years, improved crops, more diverse cropping systems, and enhanced crop management systems are needed to withstand climate change, reduce carbon and water footprints, improve soil health, minimize nutrient losses, and limit competition for land, all while ensuring profitability for producers and acceptance by consumers and by society more broadly.

Journal of Dairy Science Volume 100 Special Issue: Introduction

Journal of Dairy Science -

Humans have used cattle for food, power, fertilizer, clothing, and medicines for at least 10,000 years. The domestication of cattle allowed early humans to settle in one location or to move while maintaining an adequate food supply. As humans migrated around the planet, they took cattle with them. It is not by chance that cattle became and continue to be symbols and items of wealth and power in many cultures and regions. The ability to find and manage pasture, to store dried forages and grains, to implement systems for breeding, and to harvest both milk and meat sustainably were key in the advancement of civilizations that depended on cattle for food.

A 100-Year Review: The production of fluid (market) milk

Journal of Dairy Science -

During the first 100 years of the Journal of Dairy Science, dairy foods and dairy production dairy scientists have partnered to publish new data and research results that have fostered the development of new knowledge. This knowledge has been the underpinning of both the commercial development of the fluid milk processing industry and regulations and marketing policies for the benefit of dairy farmers, processors, and consumers. During the first 50 years, most of the focus was on producing and delivering high-quality raw milk to factories and improving the shelf life of pasteurized fluid milk.

A 100-Year Review: A century of dairy processing advancements—Pasteurization, cleaning and sanitation, and sanitary equipment design

Journal of Dairy Science -

Over the past century, advancements within the mainstream dairy foods processing industry have acted in complement with other dairy-affiliated industries to produce a human food that has few rivals with regard to safety, nutrition, and sustainability. These advancements, such as milk pasteurization, may appear commonplace in the context of a modern dairy processing plant, but some consideration of how these advancements came into being serve as a basis for considering what advancements will come to bear on the next century of processing advancements.

A 100-Year Review: Progress on the chemistry of milk and its components

Journal of Dairy Science -

Understanding the chemistry of milk and its components is critical to the production of consistent, high-quality dairy products as well as the development of new dairy ingredients. Over the past 100 yr we have gone from believing that milk has only 3 protein fractions to identifying all the major and minor types of milk proteins as well as discovering that they have genetic variants. The structure and physical properties of most of the milk proteins have been extensively studied. The structure of the casein micelle has been the subject of many studies, and the initial views on submicelles have given way to the current model of the micelle as being assembled as a result of the concerted action of several types of interactions (including hydrophobic and the formation of calcium phosphate nanoclusters).

A 100-Year Review: Microbiology and safety of milk handling

Journal of Dairy Science -

Microbes that may be present in milk can include pathogens, spoilage organisms, organisms that may be conditionally beneficial (e.g., lactic acid bacteria), and those that have not been linked to either beneficial or detrimental effects on product quality or human health. Although milk can contain a full range of organisms classified as microbes (i.e., bacteria, viruses, fungi, and protozoans), with few exceptions (e.g., phages that affect fermentations, fungal spoilage organisms, and, to a lesser extent, the protozoan pathogens Cryptosporidium and Giardia) dairy microbiology to date has focused predominantly on bacteria.

A 100-Year Review: Cheese production and quality

Journal of Dairy Science -

In the beginning, cheese making in the United States was all art, but embracing science and technology was necessary to make progress in producing a higher quality cheese. Traditional cheese making could not keep up with the demand for cheese, and the development of the factory system was necessary. Cheese quality suffered because of poor-quality milk, but 3 major innovations changed that: refrigeration, commercial starters, and the use of pasteurized milk for cheese making. Although by all accounts cold storage improved cheese quality, it was the improvement of milk quality, pasteurization of milk, and the use of reliable cultures for fermentation that had the biggest effect.

A 100-Year Review: Sensory analysis of milk

Journal of Dairy Science -

Evaluation of the sensory characteristics of food products has been, and will continue to be, the ultimate method for evaluating product quality. Sensory quality is a parameter that can be evaluated only by humans and consists of a series of tests or tools that can be applied objectively or subjectively within the constructs of carefully selected testing procedures and parameters. Depending on the chosen test, evaluators are able to probe areas of interest that are intrinsic product attributes (e.g., flavor profiles and off-flavors) as well as extrinsic measures (e.g., market penetration and consumer perception).

A 100-Year Review: Yogurt and other cultured dairy products

Journal of Dairy Science -

The history of the last 100 years of the science and technology of yogurt, sour cream, cultured butter, cultured buttermilk, kefir, and acidophilus milk has been one of continuous development and improvement. Yogurt leads the cultured dairy product category in terms of volume of production in the United States and recent research activity. Legal definitions of yogurt, sour cream and acidified sour cream, and cultured milk, including cultured buttermilk, are presented in the United States Code of Federal Regulations and summarized here.

A 100-Year Review: Milestones in the development of frozen desserts

Journal of Dairy Science -

Ice cream has come a long way since the first snow cone was made. Innovations in a variety of areas over the past century have led to the development of highly sophisticated, automated manufacturing plants that churn out pint after pint of ice cream. Significant advances in fields such as mechanical refrigeration, chilling and freezing technologies, cleaning and sanitation, packaging, and ingredient functionality have shaped the industry. Advances in our understanding of the science of ice cream, particularly related to understanding the complex structures that need to be controlled to create a desirable product, have also enhanced product quality and shelf stability.

A 100-Year Review: Advances in goat milk research

Journal of Dairy Science -

In the century of research chronicled between 1917 and 2017, dairy goats have gone from simply serving as surrogates to cows to serving as transgenic carriers of human enzymes. Goat milk has been an important part of human nutrition for millennia, in part because of the greater similarity of goat milk to human milk, softer curd formation, higher proportion of small milk fat globules, and different allergenic properties compared with cow milk; however, key nutritional deficiencies limit its suitability for infants.

A 100-Year Review: From ascorbic acid to zinc—Mineral and vitamin nutrition of dairy cows

Journal of Dairy Science -

Mineral and vitamin nutrition of dairy cows was studied before the first volume of the Journal of Dairy Science was published and is still actively researched today. The initial studies on mineral nutrition of dairy cows were simple balance experiments (although the methods available at the time for measuring minerals were anything but simple). Output of Ca and P in feces, urine, and milk was subtracted from intake of Ca and P, and if values were negative it was often assumed that cows were lacking in the particular mineral.

A 100-Year Review: Fat feeding of dairy cows

Journal of Dairy Science -

Over 100 years, the Journal of Dairy Science has recorded incredible changes in the utilization of fat for dairy cattle. Fat has progressed from nothing more than a contaminant in some protein supplements to a valuable high-energy substitute for cereal grains, a valuable energy source in its own right, and a modifier of cellular metabolism that is under active investigation in the 21st century. Milestones in the use of fats for dairy cattle from 1917 to 2017 result from the combined efforts of noted scientists and industry personnel worldwide, with much of the research published in Journal of Dairy Science.

A 100-Year Review: Carbohydrates—Characterization, digestion, and utilization

Journal of Dairy Science -

Our knowledge of the role of carbohydrates in dairy cattle nutrition has advanced substantially in the 100 years of the publication of the Journal of Dairy Science. In this review, we trace the history of scientific investigation and discovery from crude fiber, nitrogen-free extract, and “unidentified factors” to our present analytical schemes and understanding of ruminal and whole-animal utilization and effects of dietary carbohydrates. Historically, advances in research and new feeding standards occurred in parallel with and fostered by new methods of analysis.

A 100-Year Review: Protein and amino acid nutrition in dairy cows

Journal of Dairy Science -

Considerable progress has been made in understanding the protein and amino acid (AA) nutrition of dairy cows. The chemistry of feed crude protein (CP) appears to be well understood, as is the mechanism of ruminal protein degradation by rumen bacteria and protozoa. It has been shown that ammonia released from AA degradation in the rumen is used for bacterial protein formation and that urea can be a useful N supplement when lower protein diets are fed. It is now well documented that adequate rumen ammonia levels must be maintained for maximal synthesis of microbial protein and that a deficiency of rumen-degradable protein can decrease microbial protein synthesis, fiber digestibility, and feed intake.

A 100-Year Review: Metabolic modifiers in dairy cattle nutrition

Journal of Dairy Science -

The first issue of the Journal of Dairy Science in 1917 opened with the text of the speech by Raymond A. Pearson, president of the Iowa State College of Agriculture, at the dedication of the new dairy building at the University of Nebraska (J. Dairy Sci. 1:4–18, 1917). Fittingly, this was the birth of a new research facility and more importantly, the beginning of a new journal devoted to the sciences of milk production and manufacture of products from milk. Metabolic modifiers of dairy cow metabolism enhance, change, or interfere with normal metabolic processes in the ruminant digestive tract or alter postabsorption partitioning of nutrients among body tissues.

A 100-Year Review: Total mixed ration feeding of dairy cows

Journal of Dairy Science -

Total mixed rations (TMR) as we know them today did not exist in 1917. In fact, TMR are an invention of primarily the last half of the past 100 yr. Prior to that time many dairy herds were fed only forages, but dairy producers started moving toward TMR feeding as milk production per cow increased, herds became larger, freestall and large-group handling of cows became more common, and milking parlors became more prevalent. The earliest known reports in the Journal of Dairy Science of feeding “complete rations” or TMR may have appeared in the 1950s, but those studies were often reported only as abstracts at annual meetings of the American Dairy Science Association or in extension-type publications.

A 100-Year Review: Calf nutrition and management

Journal of Dairy Science -

The first calf paper, published in the May 1919 issue of the Journal of Dairy Science (JDS), described factors affecting birth body weight of different breeds of calves. Other studies were done on nonmilk ingredients, growth charts were developed, and early weaning was followed to conserve milk fed to calves. Calf papers did not report use of statistics to control or record variation or to determine whether treatment means were different. Many experiments were more observational than comparative.

A 100-Year Review: A century of dairy heifer research

Journal of Dairy Science -

The years 1917 to 2017 saw many advances in research related to the dairy heifer, and the Journal of Dairy Science currently publishes more than 20 articles per year focused on heifers. In general, nutrition and management changes made in rearing the dairy heifer have been tremendous in the past century. The earliest literature on the growing heifer identified costs of feeding and implications of growth on future productivity as major concepts requiring further study to improve the overall sustainability of the dairy herd.

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