Beef Science Commons^™

Selecting For Less: How Much Methane Can We Truly Breed Away?, Sean B. Crowley

ORBioM (Open Research BioSciences Meeting)

Background

Genetic selection has potential to reduce enteric methane emissions from cattle, but a key challenge is determining how much of the genetic variation in methane traits is independent of traits already targeted in breeding programs, such as feed intake and growth.

Methods

Methane and carbon dioxide emissions were recorded in 1,700 crossbred, indoor-fed beef cattle using Greenfeed systems. Performance data included feed intake, metabolic liveweight, average daily gain, carcass weight, and ultrasound and skeletal traits. Genetic parameters and correlations among traits were estimated using animal linear mixed models to quantify the independence of methane-related genetic variation.

Results

Daily methane …

Exploring Definitions Of Daily Enteric Methane Emission Phenotypes For Genetic Evaluations Using A Population Of Indoor-Fed Multi-Breed Growing Cattle With Feed Intake Data, Clodgah V. Ryan, Thierry Pabiou, Deirdre C. Purfield, Donagh P. Berry, Stephen Conroy, Craig P. Murphy, Ross Evans

Department of Biological Sciences Publications

Genetic selection has been identified as a promising approach for reducing enteric methane (CH₄) emissions; a prerequisite for genetic evaluations; however, these are estimates of the necessary genetic parameters based on a population representative of where the genetic evaluations will be used. The objective of this study was, therefore, to derive genetic parameters for a series of definitions of CH₄, carbon dioxide (CO₂), and dry matter intake (DMI) as well as genetic correlations between CH₄, CO₂, and DMI in a bid to address the paucity of studies involving methane emissions …

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 …

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 …

Genetic Selection For Improved Efficiency And Profitability In Beef Cattle, David Kelly

Theses

Despite the importance of feed intake and efficiency in beef production, there are still gaps in our knowledge on optimal production efficiency traits and breeding strategies for improved feed, production and economic efficiency. The objectives of this thesis were to redefine production efficiency in growing cattle by exploiting carcass information and to validate current beef breeding goals for improving efficiency, and to investigate the relationships of feeding behaviour with performance, feed efficiency, and carcass merit. Feed intake and liveweight data were available on up to 6,088 cattle, of which 3,146 had carcass data, 4,672 had ultrasound data and 1,548 had …

Optimising The Carcass Merit Of Irish Beef Cattle Using Genetic And Non-Genetic Information At The Animal And Herd Level, David Kenny

Theses

Failure of beef carcasses to achieve desirable carcass specifications represent inefficiencies within the supply chain, namely greater carcass processing costs and the inability of the resulting primal cuts to conform to high-value market specifications. Analysis of a representative sample of prime Irish beef cattle conducted in this thesis determined that 59% of cattle fail to achieve the desired carcass specifications of the supply chain at slaughter. The objective of this thesis was to use readily available information to define strategies that could help to reduce this statistic. Firstly, the likelihood of Irish beef carcasses achieving the desired carcass specifications was …

Predicting Carcass Cut Yields In Cattle From Digital Images Using Artificial Intelligence, Darragh Matthews, Thierry Pabiou, Ross D. Evans, Christian Beder, Aengus Daly

Department of Mathematics Publications

Deep Learning (DL) has proven to be a successful tool for many image classification problems but has yet to be applied to carcass images. The aim of this study was to train DL models to predict carcass cut yields and compare predictions to more standard machine learning (ML) methods. Three approaches were undertaken to predict the grouped carcass cut yields of Grilling cuts and Roasting cuts from a large dataset of 54,598 and 69,246 animals respectively. The approaches taken were (1) animal phenotypic data used as features for a range of ML algorithms, (2) carcass images used to train Convolutional …

Predicting Carcass Cut Yields In Cattle From Digitalimages Using Artificial Intelligence, Darragh Matthews

Theses

Beef carcass classification in Europe is predicated on the EUROP grid for both fatness and conformation. Although this system performs well for grouping visually similar carcasses, it cannot be used to accurately predict meat yields from these groups, especially when considered on an individual cut level. Deep Learning (DL) has proven to be a successful tool for many image classification problems but has yet to be fully proven in a regression scenario using carcass images. Here we have trained DL models to predict carcass cut yields and compared predictions to more standard machine learning (ML) methods. Three approaches were undertaken …

Feed Efficiency And Carcass Metrics In Growing Cattle, David N. Kelly, Craig Murphy, Roy D. Sleator, Michelle M. Judge, Stephen B. Conroy, Donagh P. Berry

Department of Biological Sciences Publications

Some definitions of feed efficiency such as residual energy intake (REI) and residual gain (RG) may not truly reflect production efficiency. The energy sinks used in the derivation of the traits include metabolic live-weight; producers finishing cattle for slaughter are, however, paid on the basis of carcass weight, as opposed to live-weight. The objective of the present study was to explore alternative definitions of REI and RG which are more reflective of production efficiency, and quantify their relationship with performance, ultrasound, and carcass traits across multiple breeds and sexes of cattle. Feed intake and live-weight records were available on 5,172 …

Is Tb Testing Associated With Increased Blood Interferon-Gamma Levels?, Aideen E. Kennedy, Jim O'Mahony, Noel Byrne, John Macsharry, Riona G. Sayers

Department of Biological Sciences Publications

The Republic of Ireland reports a relatively low prevalence of Johne’s disease (JD) compared to international counterparts. Postulated reasons for this include a lower average herd size and a grass-based production system. Ireland also engages in high levels of bovine tuberculosis (bTB) testing. As interferon-gamma (IFN-γ) is believed to play a key role in protecting against JD, it is our hypothesis that administration of purified protein derivative (PPD), as part of the bTB test, is associated with a systemic increase in IFN-γ production, which may potentially limit clinical progression of the disease. We studied 265 cows (202 Friesian and 63 …

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 …

Prevalence And Distribution Of Gastrointestinal Nematode Parasites And Dung Beetles Associated With Upland And Lowland Grazing Of Irish Native Dexter Cattle, Noel Dineen

Theses

Diseases such as parasitic gastroenteritis are very common in cattle and can have detrimental economic consequences on agricultural productivity. This study was conducted to establish the prevalence and distribution of gastrointestinal nematode parasites associated with Dexter cattle under an organic lowland grazing regime and an extensive upland system. A secondary aim to the study was to investigate dung beetle assemblages in upland and lowland sites and their interactions with gastrointestinal nematode parasites as they offer an alternative method of natural control to organic farming systems in particular.

Cattle weights were recorded and faecal samples were collected at the beginning and …