Publications by authors named "C Maltecca"
Homozygosity, which can arise from several genetic mechanisms including inbreeding, is frequently observed in the offspring of related parents. This inbreeding can lead to a reduced performance, due to a phenomenon known as inbreeding depression. This study assessed inbreeding depression using whole genome and regional approaches in first-lactation Australian Holsteins and Jerseys, involving approximately 33,000 Holstein and 7,000 Jersey cows born between 2000 and 2017.
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- Climate change is increasingly threatening the livestock industry by affecting animal productivity, welfare, and management, prompting a focus on enhancing livestock's climatic resilience (CR).
- A study performed genome-wide association studies on lactating sows under heat stress, identifying 31 significant single nucleotide polymorphisms (SNPs) linked to nine CR indicators and revealing that CR is a polygenic trait with small effect sizes across various chromosomes.
- Key candidate genes related to heat stress response and various physiological processes were identified, along with relevant pathways indicating links to stress, immune responses, and various traits like health and production quality in livestock.
Background: In recent years, interest has grown in quantifying resilience in livestock by examining deviations in target phenotypes. This method is based on the idea that variability in these phenotypes reflects an animal's ability to adapt to external factors. By utilizing routinely collected time-series feed intake data in pigs, researchers can obtain a broad measure of resilience.
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- - The study evaluated the genetic factors influencing Stay-ability (STAY) in Italian Charolais and Limousine beef cattle using advanced genomic prediction methods, focusing on various calving stages and their impact on longevity and farm profitability.
- - Data from over 56,000 cows across multiple herds was analyzed to establish genetic parameters and correlations between STAY and other traits like fertility and conformation, revealing distinct genetic profiles for STAY traits based on calving intervals.
- - Results indicated heritability for STAY traits, with differing levels in Limousine and Charolais breeds, and highlighted potential routes for genetic improvement in cow longevity through selective breeding practices.
Although genomic selection has led to considerable improvements in genetic gain, it has also seemingly led to increased rates of inbreeding and homozygosity, which can negatively affect genetic diversity and the long-term sustainability of dairy populations. Using genotypes from US Holstein animals from 3 distinct stud populations, we performed a simulation study consisting of 10 rounds of selection, with each breeding population composed of 200 males and 2,000 females. The investigated selection strategies consisted of selection using true breeding values, EBV, EBV penalized for the average future genomic inbreeding of progeny (PEN-EBV), or random selection (RAND).
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