Nina Melzer

Nina Melzer
Research Institute for Farm Animal Biology (FBN)

About

66
Publications
4,769
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381
Citations
Citations since 2016
43 Research Items
343 Citations
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2016201720182019202020212022020406080
2016201720182019202020212022020406080
2016201720182019202020212022020406080
Introduction
Skills and Expertise

Publications

Publications (66)
Conference Paper
Full-text available
The welfare of farm animals plays an increasingly important role in society, administration, and food production. Over the past 20 years, there has been increasing interest in a more comprehensive knowledge of how farm animals perceive and interact with their physical and social environment. This information is critical to applied ethology because...
Conference Paper
The arrangement of markers on the genome can be defined either in physical or linkage terms. While a physical map represents the inter-marker distances in base pairs, a linkage map pictures the recombination frequency between pairs of markers. The rate by which two measures are correlated varies along the chromosomes and provides insights into the...
Conference Paper
Interest is growing in practical ways to gain more insights about the social bonds in dairy cow groups and new technologies, such real-time location system (RTLS), are becoming more popular for this purpose. We investigated the influence of RTLS data quality and parameter settings on detecting direct neighbor cows in lying stalls and at the feed bu...
Article
Full-text available
Tracking data are increasingly used for studying social behavior in dairy cows but guidelines are not available regarding the appropriate system setup and data quality. In this study, we investigated the effects of system calibration, as well as data filtering and smoothing methods on the detection of the location and neighbor preferences of dairy...
Article
Full-text available
Regrouping is common practice when managing dairy cow groups, and it is known to have disruptive effects on behavior and production. The presence of a small group of familiar cows upon regrouping may provide social support and mitigate some of the negative effects. In this study we investigated (1) how regrouping affects social relationships among...
Article
Full-text available
Accurate assessments of social behavior and dominance relationships in cattle can be time consuming. We investigated whether replacements at the feed bunk and water trough—one type of agonistic interaction—can be used to automatically assess dominance relationships. Our study set out to (1) validate a replacement detection algorithm using combined...
Article
Full-text available
Delay-of-gratification paradigms, such as the famous “Marshmallow Test,” are designed to investigate the complex cognitive concepts of self-control and impulse control in humans and animals. Such tests determine whether a subject will demonstrate impulse control by choosing a large, delayed reward over an immediate, but smaller reward. Documented r...
Data
Overview of the performance of single pigs in the two groups (“quantity”: with a quantitative difference in reward, i.e., 1 vs. 4 pieces of the most preferred reward; “quality”: with a qualitative difference in reward, i.e., 1 piece of the most preferred vs. 1 piece of the least preferred reward) during the course of the delay maintenance test with...
Data
Video sample of a pig of the “quantity group” (amount: left = 1 piece vs. right = 4 pieces) choosing the small, immediate reward (left side).
Data
Overview of the performance of each pig during the discrimination test over the course of the sessions for both groups (“quantity”: with a quantitative difference in reward, i.e., 1 vs. 4 pieces of the most preferred reward; “quality”: with a qualitative difference in reward, i.e., 1 piece of the most preferred vs. 1 piece of the least preferred re...
Data
Video sample of a pig of the “quantity group” (amount: left = 1 piece vs. right = 4 pieces) switching from the larger (right side) to the smaller reward (left side) during the delay of 8 s.
Data
Overview of the omissions during the preference test: percentage of omissions with regard to the number of total trials (N = 45) per animal, percentage of items refused by the individual animals (group = “quantity” [amount: 1:4], “quality” [differentially preferred items: low:high]; animal = 1-10) from both groups (group = “quantity” [amount: 1:4],...
Data
Video sample of a pig of the “quantity group” (amount: left = 1 piece vs. right = 4 pieces) choosing to wait a delay of 8 s for the larger reward (right side).
Data
Overview of the choices during the preference test: percentage of choices made with regard to the number of total trials (N = 45) per animal, percentage of items chosen by individual animals (group = “quantity” [amount: 1:4], “quality” [differentially preferred items: low:high]; animal = 1-10) from both groups (group = “quantity” [amount: 1:4], “qu...
Article
Full-text available
Full text is freely available at: https://www.sciencedirect.com/science/article/pii/S0168159118303915
Article
Full-text available
Recent research suggests that personality, defined as consistent individual behavioral variation, in farm animals could be an important factor when considering their health, welfare, and productivity. However, behavioral tests are often performed individually and they might not reflect the behavioral differences manifested in every-day social envir...
Data
Stability of the rotated component (RC1 and RC2) scores for 33 cows in the two-dimensional space. Positions of cows are represented by a gray square in the spring and by a black triangle in the autumn. (PDF)
Data
Group novel object test results and fixed effects in spring (left) and autumn (right) for the three groups. Retested cows are marked in gray. Mean values for the retested cows are indicated by Mean rep. (XLS)
Data
Spearman’s rank correlation matrices based on the individual test parameters used in three different principal component analyses. ** P < 0.05, * P <0.1 (XLS)
Data
Arena test parameters used in the analysis and the corresponding fixed effects for each cow in the spring and autumn. (XLS)
Data
Descriptive statistics for the behavioral parameters used in three different principal component analyses and in the group test. All of the behavioral parameters were measured in seconds. (XLS)
Data
Novel object in the individual arena test (A) and group test (B). (JPG)
Data
Results of Horn’s parallel test: (A) spring, 39 cows; (B) spring, 33 cows and (C) autumn, 33 cows. (PDF)
Data
Tucker’s congruence coefficients for the similarity of the rotated components (RC1 and RC2) obtained from three different principal component analyses. (XLS)
Conference Paper
Full-text available
Investigations of socio-positive and socio-negative interactions in animal groups are relevant for animal welfare. Social tension from group composition may negatively affect individuals even in a well-designed and healthy environment. New technologies allow the automated acquisition of data suitable to assess social behavior. However, for the eval...
Conference Paper
Full-text available
The weeks after calving represent a highly sensitive period for dairy cows characterized by metabolic changes, negative energy balance and high disease prevalence. Previous work suggests that recognizing behavioural changes related to illness may help to identify cows with a higher risk of developing clinical signs. When animals become ill, they ma...
Article
Full-text available
Background: While autozygosity as a consequence of selection is well understood, there is limited information on the ability of different methods to measure true inbreeding. In the present study, a gene dropping simulation was performed and inbreeding estimates based on runs of homozygosity (ROH), pedigree, and the genomic relationship matrix were...
Conference Paper
Impulse control is the ability to resist the impulse taking an immediate but smaller/ worse reward instead of choosing a delayed but bigger/better reward. Only one study showed that pigs have the ability to show impulse control. The present study first examined whether there are differences in impulse control when the food reward differs in quality...
Conference Paper
We investigated the relationship between personality traits and the social behavior within a group using socio-negative (displacement) as well as socio-positive (grooming) interactions. In a group of 14 lactating Holstein-Friesian cows (no mother-daughter relations), we determined displacement (N=403) and grooming (N=63) events from a 2-day continu...
Article
Fitting of lactation curves is a common tool to obtain the entire milk yield as well as to estimate the main curve characteristic (such as day of peak milk yield) for a lactation. These models are primarily designed for dairy cattle, but have been applied to nondairy cattle breeds and also for other species. In this study we considered milk yield d...
Article
Full-text available
Since the introduction of the backtest for the early detection of coping strategies in piglets by Hessing in the 1990s, this behavioural test has been intensively investigated with ambiguous results. One possible explanation for this lack of consistency might be the different classification methods used in many studies, so the first aim of this res...
Conference Paper
Gene expression profiling in farm animal science becomes more and more important to gain deeper insights into molecular mechanisms of complex traits. In the recent literature the analysis of gene expression data focused frequently on tissues important for energy metabolism and health. Due to their relevance in udder health, milk production, ener...
Conference Paper
Full-text available
Abstract Text: Most biological processes, like the production of milk in cattle, are the consequence of a complex network of interacting genes. The data-driven inference and analysis of regulatory networks is a crucial step towards a better understanding of such complex phenotypic traits. It is therefore one of the main challenges in computational...
Article
Full-text available
Milk performance traits are likely influenced by both additive and non-additive (e.g. dominance) genetic effects. Genetic variation can be partitioned using genomic information. The objective of this study was to estimate genetic variance components of production and milk component traits (e.g. acetone, fatty acids), which are particularly importan...
Thesis
The presented work covers a broad spectrum of investigations, where methods and approaches from the fields of bioinformatics, biostatistics, animal breeding, genetics and systems biology were used regarding the question of improved genetic value prediction for cattle considering molecular data in addition to SNP-genotypes from cattle. In modern bre...
Conference Paper
Genomic information can be used to study the genetic architecture of some trait. In particular, when searching for eQTL, genome-wide available SNP data are employed to identify loci with impact on mRNA expression levels which are analysed successively gene by gene. For processing such multitudes of information, a rapid algorithm is desired for esti...
Article
Full-text available
In this study the benefit of metabolome level analysis for the prediction of genetic value of three traditional milk traits was investigated. Our proposed approach consists of three steps: First, milk metabolite profiles are used to predict three traditional milk traits of 1,305 Holstein cows. Two regression methods, both enabling variable selectio...
Data
Full-text available
Important SNP markers, occurring in more than seven cross-validation (CV) runs, for each milk trait obtained via the metabolite approach. For this analysis, the 10 training sets from the outer cross-validation was used. (PDF)
Data
Correlations between important milk metabolites for all investigated milk traits. The correlation values were adapted from [6]. (PDF)
Data
Known QTL regions or QTL peaks, which were filtered from the cattleQTL database [25]. The following criteria were applied: trait name equal to milk fat percentage and milk protein percentage, analysis type equal to QTL, breed equal to Holstein, and chromosome number and both flanking markers or peak markers had to be available. Based on the marker...
Article
Full-text available
Phenotypic variation can partly be explained by genetic variation, such as variation in single nucleotide polymorphism (SNP) genotypes. Genomic selection methods seek to predict genetic values (breeding values) based on SNP genotypes. To develop and to optimize these methods, simulated data are often used, which follow a rather simple genotype-phen...
Article
In the field of dairy cattle research, it is of great interest to improve the detection and prevention of diseases (e.g., mastitis and ketosis) and monitor specific traits related to the state of health and management. During the standard milk performance test, traditional milk traits are monitored, and quality and quantity are screened. In additio...
Article
Full-text available
The composition of milk is crucial to evaluate milk performance and quality measures. Milk components partly contribute to breeding scores, and they can be assessed to judge metabolic and energy status of the cow as well as to serve as predictive markers for diseases. In addition to the milk composition measures (e.g., fat, protein, lactose) tradit...
Conference Paper
The composition of milk is clue to evaluate milk performance and quality measures. Milk components partly contribute to breeding scores, and they can be assessed to judge metabolic and energy status of the cow as well as to serve as predictive markers for diseases. In addition to the milk composition measures (e.g. fat, protein, lactose) traditiona...
Conference Paper
Traditional milk phenotypes (e.g. fat, protein, lactose) are measured regularly during the standard milk performance test (MPT). To investigate the metabolic state of cow and to understand the interplay between different milk traits, it is necessary to study milk composition in more depth and to disassemble milk into its components. Using the gas c...
Data
Full-text available
The figure shows estimates of genetic effects and location if epistasis was present in the 23-QTL scenario: (a) additive, (b) dominance, (c) additive × additive and (d) additive × dominance effects for a single dataset with M2 using fBayesB. Filled circles were plotted for each estimated effect >10-4. Location of (e) additive × additive and (f) add...
Data
The fBayesB approach was applied to public data on a heterogeneous stock of mice. Genetic effects were estimated based on the different models including only additive effects (M0), additive and dominance effects (M1), additive, dominance and pairwise epistatic effects (M2).
Article
Full-text available
Molecular marker information is a common source to draw inferences about the relationship between genetic and phenotypic variation. Genetic effects are often modelled as additively acting marker allele effects. The true mode of biological action can, of course, be different from this plain assumption. One possibility to better understand the geneti...
Conference Paper
It is a challenging task to predict genetic values for traits in dairy cattle on the basis of genome-wide SNP markers. Methods including additive genetic effects have already been studied, but the importance of non-additive effects for the genetic variation is not fully understood. A better prediction of genetic values is intended, when additive, d...
Conference Paper
We are interested in predicting the genetic values for traits in dairy cattle on the basis of genome-wide SNP markers. The impact of additive genetic effects has been widely studied in the past, but the importance of non-additive effects for the genetic variation is not fully understood. From the biological perspective it is especially of interest...

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Projects

Projects (3)
Project
The complex topic of impulse/self control should be comprehensively investigated, especially related to other personality traits, cognitive abilities, social behaviour, emotional coping, etc.
Project
Statistical methods for the analysis of genetic architecture of quantitative traits
Archived project
Study of milk traits and milk components from experimental data