Publications by authors named "Laila T Dias"
This study aimed to estimate genetic parameters for race time in seconds and final ranking, as well as to analyze the genetic trends associated with race time. The study utilized a dataset consisting of 23,290 records of race times and final ranks at distances of 1,000, 1,600, and 2,000 m from 6,213 Thoroughbred horses from the São Paulo Jockey Club. Our model considered the year of the run, animal sex, race class, track conditions, the linear effect of horse weight and age, and the quadratic effect of age as fixed covariates.
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- The study examined different methods of assessing feeding behavior in Nellore cattle, focusing on "feed events" versus "meals" to understand their genetic relationships and feed efficiency.
- It analyzed multiple traits related to feeding events and meals, calculating heritabilities and correlations using sophisticated genetic models.
- Results showed that more efficient cattle had shorter feeding times and faster eating rates, suggesting a genetic link between feeding behavior and feed efficiency traits.
Correction to: Influence of different environmental challenges on the expression of reproductive traits in Holstein cattle in Southern Brazil.
Trop Anim Health Prod
October 2024
Article Synopsis
- The study evaluated how genotype-environment interactions (GEI) affect traits in Holstein cattle, specifically age at first calving (AFC), age at first service (AFS), and calving interval (CI), using data from 179,492 animals in Paraná, Brazil.
- Researchers applied a reaction norm model to assess environmental gradients and heritability of these traits, finding moderate heritability for AFC (0.23) in easier environments, but low heritability for others.
- Significant GEI effects were noted for AFC and AFS, indicating that cattle that perform well in one environment may not do so in another, highlighting the complexity of breeding strategies.
Article Synopsis
- White striping (WS) is a myopathy found in broiler chickens, marked by white stripes in muscle tissue and linked to economic losses, with its causes still unclear.
- A study identified 30 differentially expressed genes in the breast muscle of affected chickens, highlighting 14 new candidates connected to muscle development, lipid metabolism, and collagen.
- The findings suggest that while some genes might play a role in the early development of WS, the expression of others may change as the condition progresses.
Genetic association between fat-to-protein ratio and traits of economic interest in early lactation Holstein cows in Brazil.
Trop Anim Health Prod
February 2024
Article Synopsis
- The study aimed to analyze genetic factors related to the fat-to-protein ratio (F:P) in Holstein cows during early lactation, considering its relationship with milk yield, somatic cell score, and calving intervals.
- It used extensive data from over 77,000 cows collected between 2012 and 2022 and employed advanced statistical models to estimate heritability and correlations between traits.
- Findings indicated low heritability for F:P and other traits, with certain genetic correlations suggesting potential conflicts that could hinder overall genetic improvement in milk production and quality.
Cattle have a complex social organization, with negative (agonistic) and positive (affiliative) interactions that affect access to environmental resources. Thus, the social behaviour has a major impact on animal production, and it is an important factor to improve the farm animal welfare. The use of data from electronic bins to determine social competition has already been validated; however, the studies used non-free software or did not make the code available.
View Article and Find Full Text PDFThe aim of this study was to evaluate the genotype x environment interaction (GxE) for scrotal circumference (SC) measured at different ages using pedigree-based (A-1) and pedigree and genomic-based (H-1) relationship matrices. Data from 1,515 Brahman bulls, from the Cooperative Research Centre for Beef Genetic Technologies (Beef CRC) experimental dataset, were used in this study. SC was adjusted to age and body weight measured at 6 mo (SC6), 12 mo (SC12), 18 mo (SC18), and 24 mo of age (SC24).
View Article and Find Full Text PDFMilk fever is an important metabolic disorder that affects dairy cows around parturition. It is associated with a breakdown in the mechanisms of calcium homeostasis, resulting in very low blood calcium levels (hypocalcemia). The main objective of this study was to dissect the genetic basis underlying milk fever incidence in Holstein cattle.
View Article and Find Full Text PDFThis study aimed to investigate the following environmental effects in Suffolk lambing: contemporary groups, type of birth, and age of animal and age of dam at lambing on conformation (C), precocity (P), musculature (M), and body weight at postweaning (W), and the heritability coefficients and genetic correlations among these traits. Contemporary groups, type of birth, and age of animal and age of dam at lambing were significant for W. For C, all the effects studied were significant, except linear and quadratic effects of age of the animal.
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