Download or read book Estimation of Genetic Parameters for Health Problems in Holstein Cows written by Hsueh-Kung Lin and published by . This book was released on 1987 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evolution and Selection of Quantitative Traits written by Bruce Walsh and published by Oxford University Press. This book was released on 2018-06-21 with total page 1504 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantitative traits-be they morphological or physiological characters, aspects of behavior, or genome-level features such as the amount of RNA or protein expression for a specific gene-usually show considerable variation within and among populations. Quantitative genetics, also referred to as the genetics of complex traits, is the study of such characters and is based on mathematical models of evolution in which many genes influence the trait and in which non-genetic factors may also be important. Evolution and Selection of Quantitative Traits presents a holistic treatment of the subject, showing the interplay between theory and data with extensive discussions on statistical issues relating to the estimation of the biologically relevant parameters for these models. Quantitative genetics is viewed as the bridge between complex mathematical models of trait evolution and real-world data, and the authors have clearly framed their treatment as such. This is the second volume in a planned trilogy that summarizes the modern field of quantitative genetics, informed by empirical observations from wide-ranging fields (agriculture, evolution, ecology, and human biology) as well as population genetics, statistical theory, mathematical modeling, genetics, and genomics. Whilst volume 1 (1998) dealt with the genetics of such traits, the main focus of volume 2 is on their evolution, with a special emphasis on detecting selection (ranging from the use of genomic and historical data through to ecological field data) and examining its consequences.

Download or read book Estimation of Genetic Parameters and Sire Rankings for Holstein Linear Type Scores and Milk Production by Multiple Trait Analysis written by Bobby Dennis Banks and published by . This book was released on 1986 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimation of Genetic and Phenotypic Parameters of Milk Fat and Protein Yields of Holstein Cattle Under Selection written by Thomas Joseph Lawlor and published by . This book was released on 1984 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Genetic Parameters of Dairy Calf and Heifer Health written by Isaac William Haagen and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective of this dissertation was to evaluate genetic parameters of dairy calf and heifer health which are important considerations for animal wellbeing and farm profitability. Despite this, little research has been conducted regarding the genetics of health in dairy youngstock. In Chapters 2 and 3, we report genetic parameters for serum total protein in calves and the genetic correlations between serum total protein and other calf health traits. In Chapter 2, we explore serum total protein as a novel trait for selection in dairy calves. Serum total protein was measured and recorded by producers on-farm and then extracted from herd management software. Failure of passive transfer of immunity was declared for serum total protein values less than 5.2 g / dL. Stayability until 365 days of age was defined as a binary trait where calves were assigned a value of 2 if they remained in the herd and 1 if they were removed from the herd for any reason. For each trait, two datasets were analyzed: one that included all Holstein sired calves (n = 16,725) and a more restrictive dataset that required Holstein sired calves to have a recorded Holstein maternal grandsire (n = 7,518). Heritability estimates for serum total protein ranged from 0.06 to 0.08, and heritability estimates for failure of passive transfer of immunity ranged from 0.04 to 0.06. Stayability heritability estimates ranged from 0.08 to 0.11. The genetic correlation estimate between serum total protein and failure of passive transfer of immunity was near 1 while the genetic correlation estimates between serum total protein and stayability ranged from 0.19 to 0.25. Approximate genetic correlations were estimated between serum total protein and predicted transmitting abilities for health, fertility, and production traits evaluated by the Council on Dairy Cattle Breeding. Serum total protein exhibited positive approximate genetic correlations with cow livability, productive life, net merit dollars, and milk yield, and favorable correlations were also found with calving traits. Our results suggest that serum total protein is heritable and favorably correlated with measures of cow health and production. After showing that serum total protein is heritable in Chapter 3, we explore the genetic relationship between serum total protein and three additional measures of calf health: respiratory disease until 365 days of age, scours until 60 days of age, and stayability until 365 days of age. Genetic correlations were generally low between serum total protein and respiratory disease, scours, or stayability and ranged from 0.010 to 0.137 for respiratory disease and scours, respectively, with large posterior standard deviations. While numerically serum total protein exhibited an unfavorable genetic correlation with scours risk, the magnitude was small. We further explored regions of the genome explaining additive variance for serum total protein, respiratory disease, scours, and stayability through a genome-wide association analysis. The results from the genome-wide association analysis suggest that these calf traits are largely polygenic and influenced by many regions of the genome. The objectives of Chapter 4 were to estimate genetic parameters of calf health in organic US Holstein calves for three calf health traits: calf respiratory disease until 365 days of age, calf scours until 60 days of age, and heifer stayability until 365 days of age. Heritability estimates were 0.100, 0.075, and 0.085 for respiratory disease, scours, and stayability, respectively. Signs were reversed when presenting correlations such that higher correlations between scours, respiratory disease and stayability were all favored and corresponded with resistance to disease rather than risk. The genetic correlation estimate between respiratory disease resistance and stayability was 0.675. However, genetic correlation estimates between respiratory disease and scours (0.148) and between scours and stayability (0.165) were low. We also estimated approximate genetic correlations of calf health traits with other traits evaluated nationally by the Council on Dairy Cattle Breeding. These were generally low to moderate in magnitude. The strongest genetic correlation estimates were with longevity, particularly between stayability and heifer livability (0.417) and between stayability and cow livability (0.475); respiratory disease was also favorably correlated with heifer (0.355) and cow (0.296) livability. Because the approximate genetic correlation between stayability and heifer livability was only moderate in magnitude, we evaluated the random interaction of herd by sire which may indicate potential genotype by environment interaction effects; results showed that herd by sire interaction accounted for approximately 2 % of total variance. Overall, results suggest there is significant genetic variation in organic calf health, and there was potential evidence of genotype by environment interaction. Finally, in Chapter 5, we estimated genetic parameters for direct treatment costs in US organic Holstein nulliparous animals (n = 17,936). Producers provided cost estimates for veterinary treatment, on-farm supplies, and on-farm labor for respiratory disease and scours. Unique events were declared if 4 and 5 days elapsed between events for scours and respiratory disease, respectively, and treatment costs for scours and respiratory disease per animal were calculated as the product of mean treatment cost and number of unique event occurrences. Total treatment cost was calculated as the sum of respiratory disease cost, scours cost, and disposal cost (fixed at $6.00) for animals that were removed from the herd. All treatment costs were summed until 18 months of age. Average treatment costs were $56.37 and $25.21 for respiratory disease and scours, respectively. The average cost per animal were $10.19, $25.03, and $25.00 for respiratory disease, scours, and total costs, respectively. Heritability estimates ranged from 0.047 for total treatment cost to 0.057 for scours treatment costs. Total treatment cost was genetically correlated with both respiratory disease cost (0.495) and scours cost (0.465). The genetic correlation estimate between respiratory disease cost and scours cost was -0.331. Because total treatment cost was semi-continuous and right-skewed, we investigated various response variables for total treatment cost; these included total treatment cost, log-transformed treatment cost, and 2-trait conditional model with response variables any treatment cost (0 = no treatment costs; 1 = treatment cost greater than $0) and log-transformed total treatment cost conditional on treatment cost being greater than $0. The model with log-transformed total treatment cost as the response variable resulted in the highest heritability and reliability estimates while the response variable in the 2-trait model had the lowest. Predicted transmitting ability correlations with traits evaluated by the Council on Dairy Breeding were low and mostly not significant. This suggests that calf and heifer treatment costs are generally not genetically correlated with current national traits in the United States. While genetic variation for youngstock heath treatment costs was detected, heritability estimates were comparable to estimates for binary disease events despite the continuous nature of treatment costs. In conclusion, significant additive variance exists for dairy calf and heifer health traits such as serum total protein, youngstock disease, and youngstock disease treatment costs. In addition, disease and disease treatment costs were generally lowly to moderately correlated with current genetic evaluations in the United States. These results suggest there is potential to improve calf and heifer health through genetic selection.

Download or read book Estimation of Genetic Parameters for Health and Survival in a Population of Ontario Holstein Calves written by Catherine Ellen McCorquodale and published by . This book was released on 2011 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimates of Genetic and Phenotypic Parameters for Some Productive Characteristics of Holstein Friesian Cattle written by Leo Rudolph Hansen and published by . This book was released on 1964 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Categorizing Linear Type Traits on Estimates of Genetic Parameters and Sire Evaluations in Holstein Cattle written by Barbara Ann Pudalov and published by . This book was released on 1983 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy and Protein Metabolism and Nutrition written by Mario Luiz Chizzotti and published by Brill Wageningen Academic. This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Variations in feeding frequency may lead to difference in utilization of dietary nutrients. The effects of feeding frequency have been tested in growing pigs and finishing pigs using respiratory quotient and postprandial kinetics of plasma metabolites. A reduced feeding frequency resulted in an increased lipogenesis and proteolysis shortly after the meal both in growing and finishing pigs. Nevertheless, growing and finishing pigs exhibit different metabolic pathways when feeding frequency is reduced.

Download or read book The Estimation of Genetic Parameters of Test Day Dry Matter Intake Energy Intake and Milk Yield of Holstein Cows written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimation of Genetic Parameters for Live Weight in South African Holstein Cattle written by and published by . This book was released on 2014 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: A primary goal in dairy cattle breeding is to improve the profitability of milk production. Live weight is of economic importance in dairy production, but is not included in the selection objectives of South African dairy cattle. The aim of the study was to determine environmental factors influencing live weight, as well as to estimate genetic parameters for live weight in South African Holstein cattle.

Download or read book Manual of Quantitative Genetics written by Walter Alvin Becker and published by . This book was released on 1992 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Breeding for robustness in cattle written by Marija Klopcic and published by BRILL. This book was released on 2023-09-04 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: The past decade has revealed unfavourable trends in e.g. fertility, udder health and locomotion in some major dairy cattle breeds due to a large increase in production and insufficient consideration of functional traits in the breeding goals. Such unfavourable trends in some functional traits increase costs. Additionally, the enlargement of herds leads to less available labour time per individual cow. This asks for cows that are easy to handle. At the same time, society is demanding a higher welfare standard of animals. These contradicting developments have increased the desire for so called more robust animals. Robustness can be defined as 'the ability to maintain homeostasis in commonly accepted and sustainable herds of the near future'; or 'the ability of the cow to function well in the environment she lives in as well as in a wide range of climates and production systems'. This book contains a series of articles (26) dealing with the concept of robustness, including aspects like evolution, genetics, environment, animal health and welfare, and integrity. Besides the major functional traits also the links to energy balance, hot climatic conditions, and the attitude and input of stakeholders towards robustness as part of the breeding program are discussed. This book is the first attempt to summarise the available knowledge concerning this topic in cattle, making this book unique. The contributions are from authors of 16 countries from all over the world. However, the focus is presently on farm animal level, while in future robustness of the whole production system may also require additional attention.

Download or read book Population Genetics in Animal Breeding written by Franz Pirchner and published by Springer. This book was released on 1983-04 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Genetic structure of population; Changes in gene frequency; Inbreeding; Quantitative genetics; Repeatability; Heritability; Aids to selection; Empirical tests of selection theory; Crossbreeding; Breeding plans.

Download or read book Development and Categorization of Systems for Evaluating Health Fertility and Disease Resistance in Dairy Sires written by Nate Robert Zwald and published by . This book was released on 2004 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimation of Genetic Parameters and Evaluation of Breeding Program Designs with a Focus on Dairy Cattle in Low Input Production Systems written by Tong Yin and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to restrictions on feeding and management on low input farms, there are vast differences between cattle on low input and conventional farms. Therefore, variance components of the same traits recorded in low input and conventional populations might be different. Even if the variance components were different, the necessities of setting up an overall breeding goal and implementing an own breeding program in organic production system are still open to further discussion. The first objective of this study was to estimate variance components of production, reproduction and health traits meas ...

Download or read book Estimation of Genetic and Environmental Parameters of Lifetime Production Traits and Longevity in Holstein Friesian Cows written by Mozzamel Hoque and published by . This book was released on 1980 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: