Showing papers in "Journal of Dairy Science in 1975"

TL;DR: Formulation of dairy cow rations should consider the following points regarding nitrogen utilization by lactating cows: a scheme based upon metabolizable protein (absorbable protein) for calculating requirements and comparing protein sources is superior to crude or digestible protein designations.

TL;DR: Future research to delineate limiting nutrients for postruminal supplementation should prove fruitful and should make a major contribution to improved production by ruminant animals.

TL;DR: A feasible approach to production of animal protein from ruminants would be utilization of nonprotein nitrogen for rumen protein production, maximization of rumen bypass of dietary protein, and supplementation with rumen nondegradable amino acids.

TL;DR: More research on factors affecting digestive efficiency of the structural carbohydrate of plant cell walls is needed to develop a precise method for predicting total ration nutritive value of diets fed to the high producing dairy cow.

TL;DR: Mixed bacterial cultures derived from the rumen were grown in a remen fluid medium in a chemostat at three dilution rates at four growth-limiting glucose concentrations and a theoretical maximum yield glucose of 89.3 and a maintenance requirement of .26 mmol glucose per g cells per h were calculated.

TL;DR: Radioimmunoassay results are consistent with the hypothesis that an increase at proestrus in estradiol rather than progestins triggers the preovulatory surge of luteinizing hormone in the bovine.

TL;DR: As size of herds increased, reproductive efficiency, as indicated by conception rate, declined; however, milk produced per cow increased, and lengths of dry period were not influenced by production or herd size but did increase with age of cow.

TL;DR: The protease rapidly spoiled sterile milk with the development of bitter flavor, clearing, or coagulation; and the susceptibility of sterile milk to protease increased during storage of the milk.

TL;DR: For visual detection of estrus to be highly effective, sufficient time must be taken at least twice a day to catch animals with a short estrus period, and there are two visual aids to estrus detection which provide potential 24-h surveillance.

TL;DR: Milks from commercial dairy herds in Southeastern Pennsylvania were analyzed for total protein, casein, whey protein, beta-lactoglobulin, nonprotein nitrogen, and lactose contents and Brown Swiss ranked highest in yield of protein.

TL;DR: Prolonged exposure to heat of Guernsey heifers increased plasma progesterone on days 2 to 19 of the first cycle and only on days2 to 8 of the second cycle, but heat stress depressed plasma cortisol in both cycles and reduced the correlation coefficient between these steroids relative to specific stages of the estrous cycle.

TL;DR: In this paper, a simple and rapid technique for finding this inverse directly from a list of sires and dams, bypassing computation of the matrix whose inverse is wanted, is presented, which can be used to evaluate all relationships among animals to be evaluated.

TL;DR: A liquid product with the same composition as a cheese can be obtained by ultra-filtration of milk under appropriate conditions as mentioned in this paper, where rennetting and addition of starter, soft fresh or ripened cheeses have successfully been prepared from the pre-cheese.

TL;DR: Cadmium, mercury, and lead are toxic to humans and animals, but apparently cattle are more tolerant of cadmium than are other animal species, and the alkyl mercuries, especially methyl mercury, are more toxic than inorganic mercury compounds.

TL;DR: Data from 10 herds on a herd reproductive status program supported estimates of lost reproductive days per cow per year due to conception failure and missed heat as 23 and 10 days.

TL;DR: Data representing 5,062 services during 1960 to 1971 in the Florida Agricultural Experiment Station dairy herd were analyzed by least squares to delineate factors affecting conception rates and there was no evidence of breed by month or breed by season interactions.

TL;DR: A review of the relationship between lipolysis and flavor, which involves a variety of tissue and microbial lipase or esterase enzymes, can be found in this article, where the technology of application of lipolytic enzymes to flavor development in dairy products is described.

TL;DR: The current nutritional status of ruminant animals in many geographical areas and involving various feeding programs with this element has not been established, and the recent widespread deficiency problems with nonruminants suggest that such an assessment should be made.

TL;DR: Differences among teat-swab counts of cow groups and among experimental periods indicated the importance of individual cow factors and uncontrolled environmental factors on teat end bacteria.

TL;DR: It is postulated that mean ruminal ammonia concentration may be a useful criterion for predicting efficacy of non protein nitrogen supplementation and a quantitative approach for evaluating nonprotein nitrogen supplementation based upon determination of the point at whichRuminal ammonia exceeds the requirement of the ammonia-utilizing bacteria.

TL;DR: In this article, a method of writing the inverse rapidly without computing the relationship matrix itself all relationships can now be used in intraherd cow evaluation, and tests of progeny by artificial insemination on sires used in the herd can be incorporated.

TL;DR: Forty-one strains of Kluyveromyces fragilis (Jörgensen) van der Walt 1909 varied 60-fold in ability to produce lactase (beta-galactosidase) and Supplementary growth factors were unneccessary for good lactase yeilds when yeast was grown on whey media.

TL;DR: Metabolic systems in rumen mucosa of physiologically mature ruminants seem to adapt little to varying individual volatile fatty acids available for absorption in vivo.

TL;DR: In this paper, the inverse of a large numerator relationship matrix is used to compute the relationship matrix with little additional labor and the number of equations for groups to account for genetic trend and for differences among subpopulations is reduced.

TL;DR: This paper analyzes the current knowledge of mild protein chemistry to explain the reactions and their control for the major processes utilized by the modern milk processing industry.

TL;DR: In this paper, the most important identifiable relationships among sires used in artificial insemination are due to common sires and maternal grandsires and a rapid method for finding the inverse of a numerator relationship matrix resulting from use of these two points in the pedigree has been developed.

TL;DR: Cows secrete less iodine into milk than most other species and have an efficient iodine recycling system via the gastrointestinal tract which conserves iodine and can protect them against low dietary iodine.

TL;DR: Results raise possibilities that mammary gland of the lactating cow may concentrate preferentially estrone or convert estradiol to estrone, but estimated excretion of estrogen through the milk represents no more than a fraction of 1% of the total excreted during the estrous cycle, and the proportion becomes less as gestation progresses up to at least 7 mo.

TL;DR: The role of routine dry cow therapy in decreasing the number of infections in dairy herds by preventing new infections and removing old infections is demonstrated.