Ilias Kyriazakis

Queen's University Belfast | QUB · Institute for Global Food Security

1. Shifting to higher welfare systems is expected to increase their environmental impact and mitigation strategies need to be identified. The environmental impacts associated with various broiler production systems (BPS: conventional, higher welfare indoors, free-range or organic) and the characteristics of BPS which contribute to these impacts wer...

Enterococcus cecorum (EC) infection is an emerging endemic disease in UK and global broiler poultry with major economic impact and welfare concerns. There are significant research gaps with regards to EC pathogenesis, source of infection, transmission routes and early detection of disease, which this study aimed to address. In this prospective stud...

Greenhouse gas (GHG) emissions from livestock production must be urgently tackled to substantially reduce their contribution to global warming. Simply reducing livestock numbers to this end risks impacting negatively on food security, rural livelihoods and climate change adaptation. We argue that significant mitigation of livestock emissions can be...

Investigations into the role of vitamin D (vitD) in the immune response of cattle are limited. The objectives of this study were therefore to investigate the association between circulating vitD concentration, tuberculosis (TB) vaccination, and Mycobacterium bovis infection outcomes in 24 dairy calves (<8 wk old) that were housed throughout and fed...

We investigated the effects of supplementing low protein diets with methionine (Met) or threonine (Thr) during a mixed Eimeria (consisting of E. acervulina, E. maxima and E. tenella) challenge in broilers. All birds were fed the same starter diet (d1–9) and finisher diet (d28–35) which met Cobb 500 nutrient specifications. Birds were allocated to 1...

A 35-d study investigated the impact of dietary supplementation with Arginine (Arg) or branched-chain amino acids (BCAA) of broilers receiving low-protein diets whilst infected with mixed Eimeria species. All birds were given the same starter (d0–10) and finisher (d28–35) diets. The 4 grower diets used were a positive control (PC) with adequate pro...

Although pig systems start from a favourable baseline of environmental impact compared to other livestock systems, there is still scope to reduce their emissions and further mitigate associated impacts, especially in relation to nitrogen and phosphorous emissions. Key environmental impact hotspots of pig production systems are activities associated...

The feed-food competition for environmental and economic resources raises increasing concerns about the production and supply of protein for the global livestock sector. Risks to food-security and approaching deadlines for global sustainable development, means exploring alternative protein feed ingredients is imperative. This Review discusses the p...

We investigated the effects of supplementing arginine (Arg) and branched-chain amino acids (BCAA) in broilers fed reduced-protein diets and challenged with Eimeria spp. All birds were fed the same starter diet meeting Cobb 500 nutrient specifications from d 1 to 9. Four grower diets: positive control (PC) with 20.0% crude protein (CP); reduced-prot...

The solution to the central problem of nutritionists, of what will happen if a particular animal is fed in a particular way whilst kept in a specific environment at a specific point in time, relies on sufficient and accurate descriptions of animal genotype and phenotype, feeding regime, and other dimensions of the environment. Such descriptions are...

Provision of feeding strategies tailored to the dynamic, preferably individual-level nutrient requirements is expected to greatly reduce the mismatch between nutrient supply and demand of most animals and could lead to minimisation of excess nutrient excretion observed in many pig production systems. Approaches to account for the individual variati...

The objective of this study was to develop a fully automated multiple-cow real-time lameness detection system using a deep learning approach for cattle detection and pose estimation that could be deployed across dairy farms. Utilising computer vision and deep learning, the system can analyse simultaneously both the posture and gait of each cow with...

Gastrointestinal nematode (GIN) infections are ubiquitous and often cause morbidity and reduced performance in livestock. Emerging anthelmintic resistance and increasing change in climate patterns require evaluation of alternatives to traditional treatment and management practices. Mathematical models of parasite transmission between hosts and the...

The feed-food competition for environmental and economic resources raises increasing concerns about the production and supply of protein for the global livestock sector. Risks to food-security and approaching deadlines for global sustainable development, means exploring the potential for alternative protein feeds is imperative. However, as the use...

We modified an automated method capable of quantifying behaviors which we then applied to the changes associated with the post-weaning transition in pigs. The method is data-driven and depends solely on video-captured image data without relying on sensors or additional pig markings. It was applied to video images generated from an experiment during...

Ear biting is a welfare challenge in commercial pig farming. Pigs sustain injuries at the site of bite paving the way for bacterial infections. Early detection and management of this behavior is important to enhance animal health and welfare, increase productivity whilst minimizing inputs from medication. Pig management using physical observation i...

Background Pig production has been highlighted as one of the highest users of antibiotics amongst livestock, with several studies suggesting a variety of approaches to antibiotic reduction. We aimed to investigate links between antibiotic use (defined as total amount of critically (CIA) and non-critically important antibiotics, and as mg per kg of...

Change in the frequency of contact between pigs within a group may be indicative of a change in the physiological or health status of one or more pigs within a group, or indicative of the occurrence of abnormal behaviour, e.g. tail-biting. Here, we developed a novel framework that detects and quantifies the frequency of interaction, i.e., a pig hea...

Most pigs in slatted systems are provided with enrichment meeting only minimum legal requirements. We aimed to explore the effects of a novel enrichment treatment consisting of daily provided fodder beet and jute bags for pigs in slatted systems, and investigate the timing of enrichment provision on performance, health and stress resilience. We use...

Gastrointestinal nematode (GIN) parasites in grazing cattle are a major cause of production loss and their control is increasingly difficult due to anthelmintic resistance and climate change. Rotational grazing can support control and decrease reliance on chemical intervention, but is often complex due to the need to track grazing periods and infec...

HIGHLIGHTS • Nematode control in cattle is complicated by drug resistance and climate change • A model was developed to predict GIN epidemiology under varying conditions • The model incorporates cattle growth, infection and immunity, grass availability, weather • Predictions were validated against empirical studies of GIN in N Europe • The mode...

Background Piglet perinatal and pre-weaning mortality is a welfare problem causing economic losses in pig production. In this study, the effects of housing and management interventions on the economic result of sow enterprises representing six European countries (Belgium, Denmark, Finland, Germany, The Netherlands and Spain) were tested. Interventi...

A systematic review and meta-analysis was conducted to investigate the role of Eimeria species, dose and inoculation time, on performance and infection outcomes of different broiler strains infected for different study durations. The meta-analysis addressed E. acervulina, E. maxima, E. tenella and mixed species infections, and involved data from 72...

Models of pig growth seek to predict the rates of retention of protein and lipid from a knowledge of the pig and the diet fed. The first, and crucial, part of the problem is to predict the rate of protein retention. A simple rule, which we have advocated, is that the marginal efficiency of retention of dietary ideal protein, e p , is the same at al...

Precision feeding and management of growing-finishing pigs typically require mathematical models to forecast individual pig performance from past data. The current approaches, namely double exponential smoothing (DES) and dynamic linear regression are likely to have some limitations in their applicability since they: (1) assume that responses can b...

In two experiments, we investigated whether diet composition plays a role in pathogen-induced anorexia, the voluntary reduction in ADFI during infection in broilers. We hypothesised that either energy or CP dietary content could influence the extent of anorexia in Ross 308 broilers and infection outcomes with Eimeria maxima. From d13 of age, half o...

The use of alternative, often bulky ingredients is becoming widespread in poultry diets as the industry seeks to reduce its economic and environmental costs. Consequently, there is an increased need to accurately predict the performance of birds given such diets and identify their maximum capacity for bulk. We offered diets diluted with a range of...

Recent technological advances make it possible to deliver feeding strategies that can be tailored to the needs of individual pigs in order to optimise the allocation of nutrient resources and contribute toward reducing excess nutrient excretion. However, these efforts are currently hampered by the challenges associated with: (1) estimation of unobs...

The focus of this chapter is on the environmental impact consequences of endemic livestock health challenges that lead to deterioration in animal health, and on the potential impacts arising from their mitigations. The first part of the chapter concentrates on the potential of animal health to affect the environmental impact of livestock systems. S...

Purpose The environmental and economic impacts of livestock production systems are typically assessed using global characterisation factors and data, even though several impact categories call for site-specific assessments. Here, we account for spatial variability by addressing potential interactions between geographic locality and the cost-effecti...

Context The aims of global pig production systems include a reduction of their environmental impacts, which can be achieved through an increase in outputs whilst minimising inputs. Objective The aim of this paper was to develop a novel method to enable estimation of the changes in the environmental impacts based on sparse data from the British pig...

The increased frequency of hot days due to climate change can potentially impair the environmental and economic performance of pig-fattening farms. Several pig-cooling strategies have been proposed to address these impacts, however their implementation is not always economically viable and the potential environmental-economic trade-offs not well un...

This chapter focuses on the epidemiology, transmission routes, and biosecurity measures of bacterial diseases in pigs and poultry raised in intensive production systems. Bacterial pathogens are highly prevalent in these systems and cause major animal health, welfare, and production problems. There are numerous transmission routes by which bacterial...

Improved animal health can reduce greenhouse gas (GHG) emissions intensity in livestock systems while increasing productivity. Integrated modelling of disease impacts on farm-scale emissions is important in identifying effective health strategies to reduce emissions. However, it requires that modellers understand the pathways linking animal health...

Improved animal health can reduce greenhouse gas (GHG) emissions intensity in livestock systems while increasing productivity. Integrated modelling of disease impacts on farm-scale emissions is important in identifying effective health strategies to reduce emissions. However, it requires that modellers understand the pathways linking animal health...

Knowledge of periparturient longitudinal changes in sow microbiota composition is necessary to fully understand her role in the development of the piglet microbiota, but also to improve gut health and performance of the sow in lactation. Primiparous sows face the challenge of partitioning nutrients to support maternal growth in addition to supporti...

The view that genetic selection for carcass yield has limited the size of the gastrointestinal tract (GIT) of modern broilers has sparked concerns that their capacity to cope with energy dilution or bulk is also limited. We investigated the capacity of male Ross 308 broilers to deal with increasing levels of bulk and aimed to identify a feed bulk d...

This study aimed (1) to quantify the effects of positive status and vaccination practices for porcine reproductive and respiratory syndrome virus (PRRSv), swine influenza virus (SIV) and Mycoplasma hyopneumoniae (MHYO) on the profitability of farrow-to-finish pig farms and (2) to examine the financial impact of vaccination status in PRRSv and SIV p...

A multifactorial approach using environmental, performance, health and welfare parameters was used to investigate the numerous associations of ventilation throughout three consecutive fattening batches (08/2015 to 12/2016) in a farrow-to-finish commercial pig farm in Belgium. Two fattening pig units were used, unit A (1256 pigs) with mechanical ven...

Automated, vision-based early warning systems have been developed to detect behavioural changes in groups of pigs to monitor their health and welfare status. In commercial settings, automatic recording of feeding behaviour remains a challenge due to problems of variation in illumination, occlusions and similar appearance of different pigs. Addition...

Changes in pig behaviours are a useful aid in detecting early signs of compromised health and welfare. In commercial settings, automatic detection of pig behaviours through visual imaging remains a challenge due to farm demanding conditions, e.g., occlusion of one pig from another. Here, two deep learning-based detector methods were developed to id...

Background: Conventional broilers are currently one of the most efficient protein converters. Although decades of progress in genetic selection and feed formulation have lead to high standards of efficient broiler production, still a lot of variability is found between farms and between successive flocks. The aim of this study was to investigate r...

Introduction of infectious agents (e.g. African swine fever) in a farm could have severe implications beyond the farm level. Among the solutions required to minimize the risk of disease introduction and spread, the strengthening of biosecurity is a priority. Yet, although the pig fattening (finishing) herds comprise 41.2% of the pig herds on a Euro...

The gastrointestinal tract microbiota interacts with the host to modulate metabolic phenotype. This interaction could provide insights into why some low birthweight pigs can exhibit compensatory growth whilst others remain stunted. This study aimed to identify microbiota markers associated with birthweight [low birthweight (n = 13) or normal birthw...

Many emerging technologies and alternative farm management practices have the potential to improve the sustainability of pig production systems. The implementation of such practices is not always economically viable. The goal of this study was to assess the cost-effectiveness of such environmental mitigation strategies in pig systems, using an Envi...

The potential of modifications in the housing conditions and manure management to reduce the environmental impact of a European pig production system were evaluated. The study was carried out using a cradle-to-farm gate life cycle assessment (LCA), with a functional unit of 1 kg of live weight pig at farm gate. The study used Danish pig systems as...

Feeding strategies for growing monogastric livestock (particularly pigs) must focus on maximising animal performance, while attempting to reduce environmental phosphorus (P) load. Achieving these goals requires a comprehensive understanding of how different P feeding strategies affect animal responses and an ability to predict P retention. Although...

Pig production systems provide multiple benefits to humans. However, the global increase in meat consumption has profound consequences for our earth. This perspective describes two alternative scenarios for improving the sustainability of future pig production systems. The first scenario is a high input–high output system based on sustainable inten...

Purpose The environmental impacts (EIs) of the global pig production sector are expected to increase with increasing global pork demand. Although the pig breeding industry has made significant progress over the last decades in reducing its EI, previous work has been unable to differentiate between the improvements made through management improvemen...

Coccidiosis in broiler chickens, caused by infection with Eimeria spp. remains one of the most economically important production diseases. Development of a genetic biomarker panel of sub-clinical infection would be an important biological tool for the management of broiler flocks. We analysed expression of MicroRNAs (miRNAs) to determine the potent...

Several advantages would arise from the automated detection of pathologies of pig carcasses, including avoidance of the inherent risks of subjectivity and variability between human observers. Here, we develop a novel automated classification of two porcine offal pathologies at abattoir: a focal, localized pathology of the liver and a diffuse pathol...

The majority of livestock in high-income countries is raised in intensive production systems, with pigs being one of the most important food-producing animals. Worldwide, pork accounts for approximately 35% of all meat production. Intensive pig production is characterized by a high biological and economic productivity with a simultaneously low inpu...

The aim was to investigate the effect of weaning age, weaning weight, and nursery feeding regime on post-weaning performance. The focus was on pigs weaned light, as they may be better off when weaned at a later age and/or offered a specialist nursery feeding regime. Piglets (n = 1448) from one farrowing batch of 110 sows that farrowed over 2 wks, w...

There is a paradigm shift from the traditional focus on the “average” individual towards the definition and analysis of trait variation within individual life-history and among individuals in populations. This is a result of increasing availability of individual phenotypic data. The shift allows the use of genetic and environment-driven variations...

Background Conventional broilers are currently one of the most efficient protein converters. Although decades of progress in genetic selection and feed formulation have lead to high standards of efficient broiler production, still a lot of variability is found between farms and between successive flocks. The aim of this study was to investigate ris...