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- Historical Research Bulletins of the Nebraska Agricultural Experiment Station (14)
- All Graduate Theses and Dissertations, Spring 1920 to Summer 2023 (2)
- Dairy Science (1)
- Department of Animal Science: Dissertations, Theses, and Student Research (1)
- Department of Animal Science: Faculty Publications (1)
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Comparing Strategies For Selection Of Low-Density Snps For Imputation-Mediated Genomic Prediction In U.S. Holsteins, Jun He, Jiaqi Xu, Xiao-Lin Wu, Stewart Bauck, Jungjae Lee, Gota Morota, Stephen D. Kachman, Matthew L. Spangler
Comparing Strategies For Selection Of Low-Density Snps For Imputation-Mediated Genomic Prediction In U.S. Holsteins, Jun He, Jiaqi Xu, Xiao-Lin Wu, Stewart Bauck, Jungjae Lee, Gota Morota, Stephen D. Kachman, Matthew L. Spangler
Department of Animal Science: Faculty Publications
SNP chips are commonly used for genotyping animals in genomic selection but strategies for selecting low-density (LD) SNPs for imputation-mediated genomic selection have not been addressed adequately. The main purpose of the present study was to compare the performance of eight LD (6K) SNP panels, each selected by a different strategy exploiting a combination of three major factors: evenly-spaced SNPs, increased minor allele frequencies, and SNP-trait associations either for single traits independently or for all the three traits jointly. The imputation accuracies from 6K to 80K SNP genotypes were between 96.2 and 98.2%. Genomic prediction accuracies obtained using imputed 80K …
Efficiency Of Energy Utilization And Fecal Mineral Excretion In Holstein And Jersey Dairy Cows, Gabriel Garcia Gomez
Efficiency Of Energy Utilization And Fecal Mineral Excretion In Holstein And Jersey Dairy Cows, Gabriel Garcia Gomez
Department of Animal Science: Dissertations, Theses, and Student Research
Eight multiparous Holstein and 8 Jersey dairy cows were used to complete energy balance trials designed to determine the effect of breed on the production and energy efficiency of milk, and energy partitioning. A repeated switchback design was used to compare the effect of cow breed. Diets consisted of 24.5% corn silage, 18.4% alfalfa hay, 6.9% grass hay, with either 22.9% rolled corn and 14.8% soybean meal (CON) or 8.95% rolled corn and 28.8% reduced fat distillers grains (RFDDGS) DM-basis. Diets were offered ad libitum for a 28 d adaptation period and 95% ad libitum for a 4 d collection …
Ghrelin Concentrations In Milk And Plasma Of Dairy Cows During Early Lactation, Sameer M. Alhojaily
Ghrelin Concentrations In Milk And Plasma Of Dairy Cows During Early Lactation, Sameer M. Alhojaily
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Ghrelin is a hormone produced mainly by the cells lining the gastric mucosa. Ghrelin was first extracted from human and rat stomachs, and identified as an endogenous stimulator of growth hormone release. Ghrelin is synthesized and produced in several tissues, but the gastric mucosa remains the major source of circulating ghrelin. Besides growth hormone release, ghrelin stimulates appetite and plays some major roles in different organs. In several studies, ghrelin was described as a hormone with multiple functions and diverse biological actions. Ghrelin exists in two major forms, active ghrelin and inactive ghrelin, and only the active from binds to …
A Comparison Of The Efficiency And Profitability Of Holsteins And Jerseys, Kelli Ann Carstensen
A Comparison Of The Efficiency And Profitability Of Holsteins And Jerseys, Kelli Ann Carstensen
Dairy Science
The efficiency and profitability of Holstein and Jersey cows has been scrutinized, compared, and debated for many years. In response, this study was conducted with the objective of incorporating reviews and results collected from numerous studies relating to Holstein and Jersey efficiency and profitability to determine if a breed advantage existed in any or all related areas. Articles reviewed were obtained from the Journal of Dairy Science, the New Zealand Journal of Agricultural Research, and the Journal of Dairy Research. Jerseys were found to demonstrate breed advantages in pasture systems, longevity, stayability, productive life, calving ease, reproduction, heat stress under …
Influence Of Age On Milk Production Of Holstein Cows In Utah, Marvin R. Green
Influence Of Age On Milk Production Of Holstein Cows In Utah, Marvin R. Green
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Production of dairy cows is influenced by many factors, among which are: genetics, nutrition, management, disease and age. Most of these factors can be modified to maintain a high level of production. Age, however, is beyond the influence of mankind; therefore, it is important to understand the effect of age on milk and butter-fat production.
A Histological Study Of The Postnatal Development Of The Bovine Testis, R. G. Fossland, A. B. Schultze
A Histological Study Of The Postnatal Development Of The Bovine Testis, R. G. Fossland, A. B. Schultze
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
A limited number of detailed studies on the development of the bovine testis from birth to sexual maturity have been reported. Further study of bovine testis development appears desirable to furnish additional observations and to note variations that may occur during the developmental process. Information on the process of spermatogenesis should furnish a basis for experimental work designed to promote increased spermatogenic activity in the postpubertal testis as well as for work directed toward promoting complete spermatogenesis at an earlier than usual age. This report is a study of the histological picture of the testes from 56 bulls varying from …
Relation Of Heart Girth To Weight In Holsteins And Jerseys, H. P. Davis, W. W. Swett, W. R. Harvey
Relation Of Heart Girth To Weight In Holsteins And Jerseys, H. P. Davis, W. W. Swett, W. R. Harvey
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
Body weight is the one measurement most extensively used to evaluate growth, condition, and value for beef, and as a basis for calculating feed requirements for cattle. Weight can be determined readily by scales but unfortunately scales of a capacity adequate for weighing cattle are not always available. Thus there is a real need for a basis of estimating weight from some body measurement that can be obtained easily and at a minimum of cost and time. It is the aim of this study to utilize additional data now available to increase further the accuracy and reliability of estimating weight …
Growth Measurements Of Holstein, Ayrshire, Guernsey And Jersey Males, H. P. Davis, I. L. Hathaway
Growth Measurements Of Holstein, Ayrshire, Guernsey And Jersey Males, H. P. Davis, I. L. Hathaway
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
This study was based on monthly observations of all Holstein, Ayrshire, Guernsey and Jersey males born in the University of Nebraska dairy herd between 1922 and 1942. There were varying numbers of animals for the different months of age for the several breeds. Measurements of weight, slope of the rump, thickness of skin, and 13 linear measurements were taken monthly, from birth to disposal of the animals. The linear measurements were of heights at withers, hooks and rump; of lengths-diagonal (shoulder point to pinbone), body and rump; of widths at chest, hooks and pinbones; of depths at chest and barrel; …
Comparative Measurements Of Holstein, Ayrshire, Guernsey, And Jersey Females From Birth To Seven Years, H. P. Davis, I. L. Hathaway
Comparative Measurements Of Holstein, Ayrshire, Guernsey, And Jersey Females From Birth To Seven Years, H. P. Davis, I. L. Hathaway
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
Body measurements are important for a proper understanding of how growth takes place in animals. Unfortunately, few growth data other than for weight have been published concerning dairy cattle. This is a report of measurements of females in the University of Nebraska dairy herd made as part of a long-time growth study. During the period 1922 to 1942 each animal born into the herd was weighed and measured at regular intervals. Presented here are the data for weight, height, length, width, depth, girth and hide thickness for females of the Holstein, Ayrshire, Guernsey, and Jersey breeds. The average body measurements …
Growth Measurements Of Holstein Females From Birth To Seven Years, H. P. Davis, I. L. Hathaway
Growth Measurements Of Holstein Females From Birth To Seven Years, H. P. Davis, I. L. Hathaway
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
Measurements of growth, to be meaningful, must be taken of various parts of the body, at regular intervals, under standardized environmental conditions, from birth through the growth span of the animal. From these measurements skeletal growth standards may be prepared for the several ages. Such standards can be used to measure growth at any age period. They will serve the research worker as a guide for experimental procedure and will provide the livestock raiser a basis with which his animals may be compared. Present standards of growth for dairy cattle are based mostly upon live weight, although considerable data are …
Breeding Efficiency In Dairy Cattle From Artificial Insemination At Various Intervals Before And After Ovulation, George W. Trimberger
Breeding Efficiency In Dairy Cattle From Artificial Insemination At Various Intervals Before And After Ovulation, George W. Trimberger
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
The length of estrus and the time of ovulation were determined for 46 heifers and 86 cows of the Ayrshire, Guernsey, Jersey, and Holstein breeds by testing for end of estrus and ovulation at 2-hour intervals. Services were given by artificial insemination at various intervals before and after ovulation to determine the influence of this factor on the rate of conception. No significant breed or seasonal differences were found for length of estrus and ovulation time after end of estrus among the four dairy breeds represented in the experiment.
Distillers' By-Products And Soybean Meal In Dry Calf Starters For Calves On Limited Quantities Of Milk, H. P. Davis, G. W. Trimberger
Distillers' By-Products And Soybean Meal In Dry Calf Starters For Calves On Limited Quantities Of Milk, H. P. Davis, G. W. Trimberger
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
Whole milk is recognized to be very satisfactory as the principal source of nutrients for young growing calves. But the price of milk and its importance as food for human beings has tended to introduce the use of substitutes. Skim milk has been demonstrated to be a satisfactory substitute when fed with grain after the first few weeks of feeding; but since skim milk, too, has become of increased usefulness for human nutrition, this experiment, one of a series, was designed to determine whether or not combinations of various grains, when fortified with vitamins, could be substituted for the solids …
Protein Supplements In Dry Calf Starters For Calves On Limited Quantities Of Milk, George W. Trimberger, Herbert Perry Davis
Protein Supplements In Dry Calf Starters For Calves On Limited Quantities Of Milk, George W. Trimberger, Herbert Perry Davis
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
This experiment was undertaken to determine the usefulness of various high protein concentrates of animal and plant sources in comparison with dried skim milk in calf starters during the early stages of calf growth.
Conception Rate In Dairy Cattle By Artificial Insemination At Various Stages Of Estrus, George W. Trimberger, H. P. Davis
Conception Rate In Dairy Cattle By Artificial Insemination At Various Stages Of Estrus, George W. Trimberger, H. P. Davis
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
A breeding experiment with 295 dairy cows and heifers of the Jersey, Guernsey, Ayrshire, and Holstein breeds was conducted in the University of Nebraska dairy herd. The females were given artificial services at various stages of estrus to determine the effect of time of service upon conception. The results obtained indicate the potential benefits in higher percentage of conception in females bred during the middle of estrus, toward the end of estrus, and those bred in full heat and rebred in 24 hours. The latter is usually not very practical, especially in artificial breeding rings, but there are occasions when …
Relation Of Height At Withers And Chest Girth To Live Weight Of Dairy Cattle Of Different Breeds And Ages, H. P. Davis, R. F. Morgan, Samuel Brody, A. C. Ragsdale
Relation Of Height At Withers And Chest Girth To Live Weight Of Dairy Cattle Of Different Breeds And Ages, H. P. Davis, R. F. Morgan, Samuel Brody, A. C. Ragsdale
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
The size of a dairy cow is important from the standpoint of feed consumption and economy of production and also as an indication of the expected size of offspring. The ultimate disposal of dairy cattle is for beef, and the measure of returns is based upon size and condition. A method for the determination of the approximate weights of dairy females, where scales are not available, is needed. Measurements of dairy cattle which show development and skeletal growth by ages in relationship to weight are presented here for four different dairy breeds.
The Effect Of Pregnancy And Parturition On The Weight Of Dairy Cows, R. F. Morgan, H. P. Davis
The Effect Of Pregnancy And Parturition On The Weight Of Dairy Cows, R. F. Morgan, H. P. Davis
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
A study was made of the effect of pregnancy and parturition upon the weight cycle of dairy cows of the Ayrshire, Guernsey, Holstein, and Jersey breeds according to gestation periods from data accumulated from records for the period 1922 to 1934 of the dairy herd of the Dairy Husbandry Department of the University of Nebraska. The weights of the cows were obtained from three consecutive weighings made at the middle of each month and daily weighings beginning at the 265th day of pregnancy and continuing for 30 days after calving. A total of 656 separate gestation periods were tabulated according …
The Vitamin A Content Of Skimmilk, Standardized Milk, And Cream From Different Breeds Of Cows, I. L. Hathaway, H. P. Davis
The Vitamin A Content Of Skimmilk, Standardized Milk, And Cream From Different Breeds Of Cows, I. L. Hathaway, H. P. Davis
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
A study was made of the vitamin A content of skimmilk, of milk standardized by the addition of separated milk, and of cream. Rats whose body stores of vitamin A had been depleted by being fed a vitamin A deficient ration were fed either skimmilk, standardized milk, or cream as a source of vitamin A. Approximately 750 rats were used in nine experiments. From the results of these experiments the following conclusions were drawn: (1) that the vitamin A content of milk is associated largely with the butterfat and that separated milk containing a small quantity of fat contains only …
The Influence Of Number Of Daily Milkings On The Production Of Dairy Cows, R. F. Morgan, H. P. Davis
The Influence Of Number Of Daily Milkings On The Production Of Dairy Cows, R. F. Morgan, H. P. Davis
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
High-producing Holstein, Jersey, Ayrshire, and Guernsey cows of various ages milked three times daily produced from 39.69 to 52.26 per cent more fat and from 44.98 to 65.18 per cent more milk than cows milked twice daily. When high-producing cows of all breeds milked four times daily were compared with cows milked twice daily, the fat production for the several age classes varied from 110.19 to 127.53 per cent and the milk production from 149.08 to 160.31 per cent greater for those milked four times. Milking high-producing cows four times as compared with three times daily showed an increased fat …
The Vitamin A Content Of The Milk Of Holstein, Ayrshire, Jersey, And Guernsey Cows, H. P. Davis, I. L. Hathaway
The Vitamin A Content Of The Milk Of Holstein, Ayrshire, Jersey, And Guernsey Cows, H. P. Davis, I. L. Hathaway
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
A comparative study of the vitamin A content of milk produced by Holstein, Ayrshire, Jersey, and Guernsey cows was made by comparing the growth produced by 560 rats receiving milk from these breeds as their only source of vitamin A. The results showed some slight irregular differences in the gains produced by the milk from the different breeds. When these differences were considered in view of the individual variation of the experimental animals, they appeared negligible. This conclusion was substantiated by a statistical examination of the data. From the results of this study in which the experiments were duplicated, it …
Feeding The Dairy Cow, H. P. Davis
Feeding The Dairy Cow, H. P. Davis
Nebraska Agricultural Experiment Station: Historical Circulars
Cows produce milk from feed and water only. Therefore feed in proper quantity and quality is usually the limiting factor governing a cow's production up to the limit of her capacity.