Animal Sciences Commons^™

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 …

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 …

Low Cost, Multi-Purpose Genotyping Panels For Dairy And Beef Cattle, Michelle Judge

Theses

rhe selection of animals based on DNA has revolutionised animal breeding, but the associated high cost of obtaining genotypes has limited its uptake. The objective of this thesis was to develop a low-cost, low-density, multi-purpose genotyping panel for the procurement of reliable genotype information, and to quantify the long-term consequences of using such low-density genotype panels in breeding programs. The objectives were achieved through a combination of real-life cattle genotype data and simulations to mimic a cattle population. The in-silico development of genotype panels was based on actual genotypes from up to 58,705 beef cattle. Alternative novel strategies were used …