Life Sciences Commons^™

Characterisation Of Sex Chromosome Aneuploidy In Female Cattle Using Genotype Information, Cliona Ryan

ORBioM (Open Research BioSciences Meeting)

Background

Aneuploidy is a genetic condition characterized by the loss (monosomy) or gain (trisomy) of one or more chromosomes. Aneuploidy affecting the sex chromosomes often leads to infertility. The objective of this study was to estimate the prevalence of sex chromosome aneuploidy in a large juvenile population using routinely available genotype intensity information.

Methods

Genotype and genotype intensity data was available on 145,476 female dairy and beef cattle below 15 months of age at the time of genotyping, with no recorded progeny. Genotype intensity data included the LogR Ratio (LRR), R-value (the sum of X and Y SNP probe intensities), …

Grass-Based Supplementation To Reduce Slaughter Age In Dairy-Beef Steers, Jamie O'Driscoll

ORBioM (Open Research BioSciences Meeting)

Background

Reducing slaughter age, while maintaining carcass output, will improve the sustainability of beef production systems. This will result in lower lifetime emissions from cattle, while also reducing the carbon equivalent per kilogram of beef carcass. The objective of this study was to investigate the strategic use of concentrate feed within pasture-based dairy-beef steer production systems, to establish its effectiveness in reducing slaughter age in differing animal genotypes.

Methods

Three contrasting supplementation strategies were implemented: 1) grass only (GO), pasture only diet in the first and second grazing season, 2) intermediate (INTER), concentrate supplementation throughout the first grazing season, pasture …

The Detection Of Putative Recessive Lethal Haplotypes In Irish Sheep Populations, Rory Mcauley

ORBioM (Open Research BioSciences Meeting)

In livestock populations, recessive lethal alleles are a known contributor to poor reproductive performance due to embryonic death in homozygous individuals. Despite their lethal effect in the recessive form, these alleles may be maintained at high frequencies among carrier animals because of their positive pleiotropic effects on economically important traits. Although several such recessive alleles have been identified in cattle and pig populations, limited studies have been completed in sheep, and none within Irish sheep populations. Genotype data for 69,034 animals from five major Irish sheep breeds genotyped on a variety of panels was available for this study. Only animals …

Clearing The Air Between Methane And Commercial Beef Cattle In Ireland, Clodagh V. Ryan

ORBioM (Open Research BioSciences Meeting)

Background

Rumen methanogenesis is the single most significant source of anthropogenic methane (CH₄) emissions. This research aimed to analyse CH₄ data recorded by GreenFeed systems by assessing the repeatability of such phenotypic measures, estimating the heritability of CH₄, and generating CH₄ estimated breeding values (EBVs) for inclusion in the national breeding index_.

Methods

CH₄ measurements were recorded on 979 cattle for 20 to 83 days using GreenFeed machines, resulting in 211,136 individual CH₄ observations. The phenotypic repeatability of CH₄ was estimated for six different averaging periods using a linear mixed …

Genetic Variations In The Myostatin Gene Among Irish Cattle Breeds, Cliona Ann Ryan

ORBioM (Open Research BioSciences Meeting)

No abstract provided.

Mining Of Producer Recorded Data; Using Beef Calf And Cow Live-Weight Data As A Case Study, Shauna Walsh

ORBioM (Open Research BioSciences Meeting)

Animal live-weight contributes to profitability in beef herds and is a key determinant of overall efficiency of the beef sector. The objective was to develop a novel editing criteria for anomaly detection of beef cow and calf live-weight data. Live-weight data from five sources (i.e., professionally-recorded, owned-scales, borrowed-scales, scales hired from a depot, other) were available from the Irish Cattle Breeding Federation.

A number of alternative methods were used for anomaly detection including: generation of within-herd regression estimates, partial correlations between cow and calf live-weight records and mahalanobis distance. Across each method a value was calculated for each herd based …

Validation Of The Irish National Sheep Genetic Evaluations, Niamh Barry

ORBioM (Open Research BioSciences Meeting)

Background: In Ireland, national sheep genetic evaluations have been implemented since 2009, however, to date no large scale study has been undertaken to investigate the accuracy of genetic evaluations in a large multi-breed population. The aim of this study was to validate the estimated breeding values (EBV) on a range of traits, using national data comprising 203,469 records across a range of phenotypic traits from 9,377 flocks.

Methods: The association between direct and maternal EBV on a range of lamb growth traits was quantified using a fixed effects model. For the lambing traits the association between direct and maternal EBV …

An Investigation Of The Novel Use Of Bacteriophages To Diagnose And Treat Johne's Disease In Cattle, Max Kevane-Campbell

ORBioM (Open Research BioSciences Meeting)

Johne’s disease is a scourge to dairy farmers all over the world. It is an infectious disease that causes chronic inflammation and lesions along the inside of the small intestine of, primarily, ruminant animals (i.e., cattle and sheep). It is an incurable disease and urgently requires new and radical intervention strategies. Apart from careful on-site farm management practices, little can be offered to farmers to reduce the risk of infection, and nothing short of livestock culling is effective once an animal becomes infected. Currently, there are no vaccines licensed in Ireland or antibiotic treatment strategies available for Johne’s disease. This …