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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 unobserved traits from the available data on bodyweight and feed consumption; and (2) characterisation of the distributions and correlations of these unobserved traits to generate accurate estimates of individual level variation among pigs. Here, alternative quantitative approaches to these challenges, based on the principles of inverse modelling and separately inferring individual level distributions within a Bayesian context were developed and incorporated in a proposed precision feeding modelling framework. The objectives were to: (i) determine the average and distribution of individual traits characterising growth potential and body composition in an empirical population of growing-finishing barrows and gilts; (ii) simulate the growth and excretion of nitrogen and phosphorus of the average pig offered either a commercial two-phase feeding plan, or a precision feeding plan with daily adjustments; and (iii) simulate the growth and excretion of nitrogen and phosphorus across the pig population under two scenarios: a two-phase feeding plan formulated to meet the nutrient requirements of the average pig or a precision feeding plan with daily adjustments for each and every animal in the population. The distributions of mature bodyweight and ratio of lipid to protein weights at maturity had median (IQR) values of 203 (47.8) kg and 2.23 (0.814) kg/kg, respectively; these estimates were obtained without any prior assumptions concerning correlations between the traits. Overall, it was found that a proposed precision feeding strategy could result in considerable reductions in excretion of nitrogen and phosphorus (average pig: 8.07 and 9.17% reduction, respectively; heterogenous pig population: 22.5 and 22.9% reduction, respectively) during the growing-finishing period from 35 to 120 kg bodyweight. This precision feeding modelling framework is anticipated to be a starting point toward more accurate estimation of individual level nutrient requirements, with the general aim of improving the economic and environmental sustainability of future pig production systems.
Maciej M. Misiura; Joao A. N. Filipe; Ilias Kyriazakis. A Novel Estimation of Unobserved Pig Growth Traits for the Purposes of Precision Feeding Methods. Frontiers in Veterinary Science 2021, 8, 1 .
AMA StyleMaciej M. Misiura, Joao A. N. Filipe, Ilias Kyriazakis. A Novel Estimation of Unobserved Pig Growth Traits for the Purposes of Precision Feeding Methods. Frontiers in Veterinary Science. 2021; 8 ():1.
Chicago/Turabian StyleMaciej M. Misiura; Joao A. N. Filipe; Ilias Kyriazakis. 2021. "A Novel Estimation of Unobserved Pig Growth Traits for the Purposes of Precision Feeding Methods." Frontiers in Veterinary Science 8, no. : 1.
Johannes Charlier; Eric R. Morgan; Ilias Kyriazakis. Quantifying the Interrelationship between Livestock Infections and Climate Change: Response to Ezenwa et al. Trends in Ecology & Evolution 2021, 36, 576 -577.
AMA StyleJohannes Charlier, Eric R. Morgan, Ilias Kyriazakis. Quantifying the Interrelationship between Livestock Infections and Climate Change: Response to Ezenwa et al. Trends in Ecology & Evolution. 2021; 36 (7):576-577.
Chicago/Turabian StyleJohannes Charlier; Eric R. Morgan; Ilias Kyriazakis. 2021. "Quantifying the Interrelationship between Livestock Infections and Climate Change: Response to Ezenwa et al." Trends in Ecology & Evolution 36, no. 7: 576-577.
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 understood. Here, we propose and implement a novel framework for environmental and economic evaluation of pig-cooling strategies in a whole farm context. We also demonstrate through a sensitivity analysis how such models can be integrated with projected climate data to investigate how climate change may affect the assessment of capital investments that are made over significant timescales. We considered two strategies implemented in a pig-fattening farm in south Sweden: pig-cooling with showers and with increased air velocity. Operation of the farm under non-cooling conditions was considered as the baseline system against which the analysis was conducted. We calculated whole-farm annual equivalent values (AEV) with the implementation of each strategy through a discounted cash flow analysis and annualised system environmental impact through a life cycle assessment. Both cooling strategies significantly reduced system environmental impact across all categories except water footprint. Acidification potential was reduced the most, exhibiting a −3.28% reduction with pig showers and −1.51% with increased air velocity. Farm profitability improved by +6.79% with showers and +3.37% with increased air velocity. Ambient temperature increase under non-cooling conditions significantly increased all impact categories with acidification being affected the most (+2.24%), and caused a −4.43% decrease in AEV. Both pig-cooling strategies mitigated these effects on system environmental performance. With increased air velocity we observed a +0.718% increase in acidification, while pig showers were the more resilient option exhibiting a +0.690% increase. The study represents a case-in-point for how to rationalise economically environmental management technologies in pig housing systems based on their cost-effectiveness in mitigating environmental impacts.
Georgios Pexas; Stephen G. Mackenzie; Knut-Håkan Jeppsson; Anne-Charlotte Olsson; Michael Wallace; Ilias Kyriazakis. Environmental and economic consequences of pig-cooling strategies implemented in a European pig-fattening unit. Journal of Cleaner Production 2021, 290, 125784 .
AMA StyleGeorgios Pexas, Stephen G. Mackenzie, Knut-Håkan Jeppsson, Anne-Charlotte Olsson, Michael Wallace, Ilias Kyriazakis. Environmental and economic consequences of pig-cooling strategies implemented in a European pig-fattening unit. Journal of Cleaner Production. 2021; 290 ():125784.
Chicago/Turabian StyleGeorgios Pexas; Stephen G. Mackenzie; Knut-Håkan Jeppsson; Anne-Charlotte Olsson; Michael Wallace; Ilias Kyriazakis. 2021. "Environmental and economic consequences of pig-cooling strategies implemented in a European pig-fattening unit." Journal of Cleaner Production 290, no. : 125784.
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 dimension responsible for limiting feed intake (FI). About 528 day-old broilers were allocated to 48 pens and offered a common starter feed until day 8, and 1 of 7 feeds from day 8 to 36 of age: a basal control (B), which was diluted to 3 levels (15, 30, or 45%) with either oat hulls (OH) or sugar beet pulp (SBP). Feed intake was measured daily and birds were dissected for GIT measurements at day 15, 22, and 36. Feed intake increased in birds offered OH15 (135 g/d), OH30 (140 g/d), and SBP15 (138 g/d) compared with birds offered the B feed (106 g/d; SEM 2.4). By increasing FI, birds were able to compensate for the lower energy content of their feeds. The greatest increase in FI was seen on OH30: its energy content (2,273 kcal/kg) was 26% lower than the B feed (3,081 kcal/kg). There was evidence of adaptation on the bulky feeds, as during the last week only birds on SBP45 were limited in FI and performance. The relative weights of the GIT were greater in the SBP than OH series, suggesting that the former needed to accommodate a higher bulk intake. For the OH series the increase in the relative GIT weights was confined to the gizzard and small intestine; whereas for the SBP series, the increase was extended to proventriculus and large intestine. Because only SBP45 was limiting FI, we were unable to identify a bulk dimension to be used to predict FI. Our data reject the suggestion that modern broilers have a reduced ability to cope with reductions in feed energy content.
James Taylor; Panagiotis Sakkas; Ilias Kyriazakis. What are the limits to feed intake of broilers on bulky feeds? Poultry Science 2020, 100, 100825 .
AMA StyleJames Taylor, Panagiotis Sakkas, Ilias Kyriazakis. What are the limits to feed intake of broilers on bulky feeds? Poultry Science. 2020; 100 (3):100825.
Chicago/Turabian StyleJames Taylor; Panagiotis Sakkas; Ilias Kyriazakis. 2020. "What are the limits to feed intake of broilers on bulky feeds?" Poultry Science 100, no. 3: 100825.
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 ventilation and unit B (1264 pigs) with natural ventilation. Animal genetics, nutrition, stocking density and health management were the same for both units. Key environmental indicators were monitored in real-time (temperature, humidity, CO2 and NH3) and the daily prevalence of respiratory disease cases was recorded to monitor the temporal expression of disease over time within a farm environment. The welfare status of the animals was assessed twice per production round (batch) with a simplified version of the Welfare quality® protocol. Serological tests for the most prevalent respiratory infectious agents (Mycoplasma hyopneumonniae, swine influenza virus (subtypes H1N1, H1N2 and H3N2), Actinobacillus pleuropneumoniae serotypes 1-2-9-11 and porcine circovirus type 2) were performed during the first, second and final third of each fattening period. Finally, key performance parameters were calculated (average daily growth, feed conversion ratio) and upon slaughter lungs from pigs from unit A (n: 782) and from unit B (n: 544) were assessed for the presence of lung lesions, pleurisy and fissures. To identify the associations of ventilation on the aforementioned parameters, statistical models were run that also included other factors (when applicable) namely production batch, season, age and sampling. Overall, the use of natural ventilation was associated with a less optimal environment with regards to thermal comfort (p < 0.001), CO2 (p < 0.001) and NH3 (p < 0.001). A higher daily prevalence of respiratory disease cases was seen in the naturally-ventilated unit (p < 0.001). Concerning the sero-prevalence of the infectious agents tested, the odds to have a positive H1N1 sample were 3.17 higher in the naturally-ventilated unit (p = 0.003). From the visual assessment of the lungs no statistically significant associations were seen between ventilation type and the presence of lesions, fissures or pleuritis. Yet, the lung lesion score was expected to be lower in the naturally-ventilated unit (p = 0.010). Regarding performance parameters, feed conversion ratio and average daily gain were overall better in the mechanically-ventilated unit (descriptive results). Finally, a better welfare score was seen in the mechanically-ventilated unit in all three production batches (descriptive results). In conclusion, the mechanically-ventilated farm was associated with better environmental conditions for the fattening pigs. Yet, further research is needed to reach definite causal claims.
Ilias Chantziaras; Dimitri De Meyer; Lode Vrielinck; Tommy Van Limbergen; Carlos Pineiro; Jeroen Dewulf; Ilias Kyriazakis; Dominiek Maes. Environment-, health-, performance- and welfare-related parameters in pig barns with natural and mechanical ventilation. Preventive Veterinary Medicine 2020, 183, 105150 .
AMA StyleIlias Chantziaras, Dimitri De Meyer, Lode Vrielinck, Tommy Van Limbergen, Carlos Pineiro, Jeroen Dewulf, Ilias Kyriazakis, Dominiek Maes. Environment-, health-, performance- and welfare-related parameters in pig barns with natural and mechanical ventilation. Preventive Veterinary Medicine. 2020; 183 ():105150.
Chicago/Turabian StyleIlias Chantziaras; Dimitri De Meyer; Lode Vrielinck; Tommy Van Limbergen; Carlos Pineiro; Jeroen Dewulf; Ilias Kyriazakis; Dominiek Maes. 2020. "Environment-, health-, performance- and welfare-related parameters in pig barns with natural and mechanical ventilation." Preventive Veterinary Medicine 183, no. : 105150.
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 identify pig postures and drinking behaviours of group-housed pigs. We first tested the system ability to detect changes in these measures at group-level during routine management. We then demonstrated the ability of our automated methods to identify behaviours of individual animals with a mean average precision of $$0.989 \pm 0.009$$ 0.989 ± 0.009 , under a variety of settings. When the pig feeding regime was disrupted, we automatically detected the expected deviations from the daily feeding routine in standing, lateral lying and drinking behaviours. These experiments demonstrate that the method is capable of robustly and accurately monitoring individual pig behaviours under commercial conditions, without the need for additional sensors or individual pig identification, hence providing a scalable technology to improve the health and well-being of farm animals. The method has the potential to transform how livestock are monitored and address issues in livestock farming, such as targeted treatment of individuals with medication.
Ali Alameer; Ilias Kyriazakis; Jaume Bacardit. Automated recognition of postures and drinking behaviour for the detection of compromised health in pigs. Scientific Reports 2020, 10, 1 -15.
AMA StyleAli Alameer, Ilias Kyriazakis, Jaume Bacardit. Automated recognition of postures and drinking behaviour for the detection of compromised health in pigs. Scientific Reports. 2020; 10 (1):1-15.
Chicago/Turabian StyleAli Alameer; Ilias Kyriazakis; Jaume Bacardit. 2020. "Automated recognition of postures and drinking behaviour for the detection of compromised health in pigs." Scientific Reports 10, no. 1: 1-15.
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 risk- and/or protective factors for poor health and performance in conventional broiler-farms in Europe by developing eight multivariable linear mixed models. Three different models were used to investigate mortality (overall, first week, after first week), three models for performance variables (growth, feed conversion, European production index) and two models were related to slaughterhouse data (i.e. dead on arrival and condemnation rate). Results Several factors related to management and housing were significantly associated with health and performance of broilers. The following factors were associated with increased mortality: floor quality, neonatal septicemia, ventilation type and other professional activities of the farmer. The factors associated with performance were chick sex, coccidiosis infections, necrotic enteritis, dysbacteriosis, light intensity adaptations, ventilation type, comparing daily flock results with previous flock results by farmer, daily check of feed and water system and type of feed. For dead on arrival three risk factors were identified i.e. daily growth, type of light adaptation and type of drinkers system. For condemnation rate seven risk factors were found, i.e. type of drinking system, daily growth, feed withdrawal time, type of ventilation, house size, septicemia after seven days and type of feed. Conclusions These results imply that a multifactorial approach is required with adaptations involving both improvements in management, housing, health programs and an increasing level of professionalism of the farmer in order to improve broiler performance and health.
Tommy Van Limbergen; Steven Sarrazin; Ilias Chantziaras; Jeroen Dewulf; Richard Ducatelle; Ilias Kyriazakis; Paul McMullin; Jesús Méndez; Jarkko K. Niemi; Sotiris Papasolomontos; Piotr Szeleszczuk; Johan Van Erum; Dominiek Maes; PROHEALTH consortium. Risk factors for poor health and performance in European broiler production systems. BMC Veterinary Research 2020, 16, 1 -13.
AMA StyleTommy Van Limbergen, Steven Sarrazin, Ilias Chantziaras, Jeroen Dewulf, Richard Ducatelle, Ilias Kyriazakis, Paul McMullin, Jesús Méndez, Jarkko K. Niemi, Sotiris Papasolomontos, Piotr Szeleszczuk, Johan Van Erum, Dominiek Maes, PROHEALTH consortium. Risk factors for poor health and performance in European broiler production systems. BMC Veterinary Research. 2020; 16 (1):1-13.
Chicago/Turabian StyleTommy Van Limbergen; Steven Sarrazin; Ilias Chantziaras; Jeroen Dewulf; Richard Ducatelle; Ilias Kyriazakis; Paul McMullin; Jesús Méndez; Jarkko K. Niemi; Sotiris Papasolomontos; Piotr Szeleszczuk; Johan Van Erum; Dominiek Maes; PROHEALTH consortium. 2020. "Risk factors for poor health and performance in European broiler production systems." BMC Veterinary Research 16, no. 1: 1-13.
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. Additionally, such systems, which rely on pig tracking, often overestimate the actual time spent feeding, due to the inability to identify and/or exclude non-nutritive visits (NNV) to the feeding area. To tackle these problems, we have developed a robust, deep learning-based feeding detection method that (a) does not rely on pig tracking and (b) is capable of distinguishing between feeding and NNV for a group of pigs. We first validated our method using video footage from a commercial pig farm, under a variety of settings. We demonstrate the ability of this automated method to identify feeding and NNV behaviour with high accuracy (99.4% ± 0.6%). We then tested the method's ability to detect changes in feeding and NNV behaviours during a planned period of food restriction. We found that the method was able to automatically quantify the expected changes in both feeding and NNV behaviours. Our method is capable of monitoring robustly and accurately the feeding behaviour of groups of commercially housed pigs, without the need for additional sensors or individual marking. This has great potential for application in the early detection of health and welfare challenges of commercial pigs.
Ali Alameer; Ilias Kyriazakis; Hillary A. Dalton; Amy L. Miller; Jaume Bacardit. Automatic recognition of feeding and foraging behaviour in pigs using deep learning. Biosystems Engineering 2020, 197, 91 -104.
AMA StyleAli Alameer, Ilias Kyriazakis, Hillary A. Dalton, Amy L. Miller, Jaume Bacardit. Automatic recognition of feeding and foraging behaviour in pigs using deep learning. Biosystems Engineering. 2020; 197 ():91-104.
Chicago/Turabian StyleAli Alameer; Ilias Kyriazakis; Hillary A. Dalton; Amy L. Miller; Jaume Bacardit. 2020. "Automatic recognition of feeding and foraging behaviour in pigs using deep learning." Biosystems Engineering 197, no. : 91-104.
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 birthweight pigs (n = 13)] and performance [“good” or “poor” average daily gain (ADG) class]. Furthermore, the study determined whether the taxonomic markers were longitudinal, or time point specific in their ability to identify low birthweight pigs who could exhibit compensatory growth. Faecal samples were collected and liveweight recorded at 10 different time points from birth to 56 days of age. No consistent associations between birthweight, performance and gut microbiota were found across all time points. However, there was a significant (P < 0.05) effect of birthweight on microbiota richness at 21, 27, 32 and 56 days of age. Significant differences (P < 0.05) in genera abundance according to birthweight and performance were also identified. Low birthweight pigs had a significantly (P < 0.05) lower abundance of Ruminococcaceae UCG-005, but a significantly (P < 0.05) higher abundance of Ruminococcaceae UCG-014 on days 21 and 32, respectively. Piglets classified as having a “good” ADG class had a significantly (P < 0.05) higher abundance of Lactobacillus, unclassified Prevotellaceae and Ruminococcaceae UCG-005 on days 4, 8 and 14, respectively. Furthermore, Ruminococcaceae UCG-005 was significantly more abundant at 14 days of age in normal birthweight pigs with a “good” ADG class compared to those classified as “poor.” The results of this study indicate that there are time point-specific differences in the microbiota associated with birthweight and performance, corresponding to the period in which solid feed intake first occurs. Identifying early-life microbiota markers associated with performance emphasises the importance of the neonatal phase when considering intervention strategies aimed at promoting performance.
Clare H. Gaukroger; Christopher J. Stewart; Sandra A. Edwards; John Walshaw; Ian P. Adams; Ilias Kyriazakis. Changes in Faecal Microbiota Profiles Associated With Performance and Birthweight of Piglets. Frontiers in Microbiology 2020, 11, 917 .
AMA StyleClare H. Gaukroger, Christopher J. Stewart, Sandra A. Edwards, John Walshaw, Ian P. Adams, Ilias Kyriazakis. Changes in Faecal Microbiota Profiles Associated With Performance and Birthweight of Piglets. Frontiers in Microbiology. 2020; 11 ():917.
Chicago/Turabian StyleClare H. Gaukroger; Christopher J. Stewart; Sandra A. Edwards; John Walshaw; Ian P. Adams; Ilias Kyriazakis. 2020. "Changes in Faecal Microbiota Profiles Associated With Performance and Birthweight of Piglets." Frontiers in Microbiology 11, no. : 917.
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 potential for these in diagnosing coccidiosis in broiler flocks. miRNA expression, in the ilea of Ross 308 broilers, was compared between chickens naturally clinically or sub-clinically infected with Eimeria maxima and Eimeria acervulina using NextSeq 500 sequencing. 50 miRNAs with greatest coefficient of variance were determined and principal component analysis showed that these miRNAs clustered within the clinical and sub-clinical groups much more closely than uninfected controls. Following false detection rate analysis and quantitative PCR we validated 3 miRNAs; Gallus gallus (gga)-miR-122-5p, gga-miR-205b and gga-miR-144-3p, which may be used to diagnose sub-clinical coccidiosis.
Tim Giles; Tommy van Limbergen; Panagiotis Sakkas; Lily Quinn; Aouatif Belkhiri; Dominiek Maes; Ilias Kyriazakis; Paul Barrow; Neil Foster. Diagnosis of sub-clinical coccidiosis in fast growing broiler chickens by MicroRNA profiling. Genomics 2020, 112, 3218 -3225.
AMA StyleTim Giles, Tommy van Limbergen, Panagiotis Sakkas, Lily Quinn, Aouatif Belkhiri, Dominiek Maes, Ilias Kyriazakis, Paul Barrow, Neil Foster. Diagnosis of sub-clinical coccidiosis in fast growing broiler chickens by MicroRNA profiling. Genomics. 2020; 112 (5):3218-3225.
Chicago/Turabian StyleTim Giles; Tommy van Limbergen; Panagiotis Sakkas; Lily Quinn; Aouatif Belkhiri; Dominiek Maes; Ilias Kyriazakis; Paul Barrow; Neil Foster. 2020. "Diagnosis of sub-clinical coccidiosis in fast growing broiler chickens by MicroRNA profiling." Genomics 112, no. 5: 3218-3225.
Feeding strategies for growing monogastric livestock (particularly pigs) must focus on maximising animal performance, while attempting to reduce environmental 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 along with Ca, P is the most researched macromineral in pig nutrition, knowledge gaps still exist in relation to: (1) the effects of P feed content on feed intake (FI); (2) the impact of P intake on body composition; (3) the distribution of absorbed P to pools within the body. Here, we address these knowledge gaps by gathering empirical evidence on the effects of P-deficient feeds and by developing a predictive, mechanistic model of P utilisation and retention incorporating this evidence. Based on our statistical analyses of published literature data, we found: (1) no change in FI response in pigs given lower P feed contents; (2) the body ash–protein relationship to be dependent upon feed composition, with the isometric relationship only holding for pigs given balanced feeds and (3) the priority to be given towards P retention in soft tissue over P retention in bones. Subsequent results of the mechanistic model of P retention indicated that a potential reduction in P feeding recommendations could be possible without compromising average daily gain; however, such a reduction would impact P deposition in bones. Our study enhances our current knowledge of P utilisation and by extension excretion and could contribute towards developing more accurate P feeding guidelines.
Maciej M. Misiura; João A. N. Filipe; Carrie L. Walk; Ilias Kyriazakis. How do pigs deal with dietary phosphorus deficiency? British Journal of Nutrition 2020, 124, 256 -272.
AMA StyleMaciej M. Misiura, João A. N. Filipe, Carrie L. Walk, Ilias Kyriazakis. How do pigs deal with dietary phosphorus deficiency? British Journal of Nutrition. 2020; 124 (3):256-272.
Chicago/Turabian StyleMaciej M. Misiura; João A. N. Filipe; Carrie L. Walk; Ilias Kyriazakis. 2020. "How do pigs deal with dietary phosphorus deficiency?" British Journal of Nutrition 124, no. 3: 256-272.
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 intensification, maximizing animal protein production efficiency on a limited land surface at the same time as minimizing environmental impacts. The second scenario is a reduced input-reduced output system based on selecting animals that are more robust to climate change and are better adapted to transform low quality feed (local feeds, feedstuff co-products, food waste) into meat. However, in contrast to the first scenario, the latter scenario results in reduced predicted yields, reduced production efficiency and possibly increased costs to the consumer. National evaluation of the availability of local feed and feedstuff co-product alternatives, determination of limits to feed sourced from international markets, available land for crop and livestock production, desired production levels, and a willingness to politically enforce policies through subsidies and/or penalties are some of the considerations to combine these two scenarios. Given future novel sustainable alternatives to livestock animal protein, it may become reasonable to move towards an added general premium price on 'protein from livestock animals' to the benefit of promoting higher incomes to farmers at the same time as covering the extra costs of, politically enforced, welfare of livestock animals in sustainable production systems. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Wendy M Rauw; Lotta Rydhmer; Ilias Kyriazakis; Margareth Øverland; Hélène Gilbert; Jack Cm Dekkers; Susanne Hermesch; Alban Bouquet; Emilio Gómez Izquierdo; Isabelle Louveau; Luis Gomez‐Raya. Prospects for sustainability of pig production in relation to climate change and novel feed resources. Journal of the Science of Food and Agriculture 2020, 100, 3575 -3586.
AMA StyleWendy M Rauw, Lotta Rydhmer, Ilias Kyriazakis, Margareth Øverland, Hélène Gilbert, Jack Cm Dekkers, Susanne Hermesch, Alban Bouquet, Emilio Gómez Izquierdo, Isabelle Louveau, Luis Gomez‐Raya. Prospects for sustainability of pig production in relation to climate change and novel feed resources. Journal of the Science of Food and Agriculture. 2020; 100 (9):3575-3586.
Chicago/Turabian StyleWendy M Rauw; Lotta Rydhmer; Ilias Kyriazakis; Margareth Øverland; Hélène Gilbert; Jack Cm Dekkers; Susanne Hermesch; Alban Bouquet; Emilio Gómez Izquierdo; Isabelle Louveau; Luis Gomez‐Raya. 2020. "Prospects for sustainability of pig production in relation to climate change and novel feed resources." Journal of the Science of Food and Agriculture 100, no. 9: 3575-3586.
Coccidiosis penalizes calcium (Ca), phosphorus (P), and fat-soluble vitamin status, as well as bone mineralization in broiler chickens. We hypothesized that dietary vitamin D (VitD) supplementation in the form of 25-hydroxycholecalciferol (OHD), compared to cholecalciferol (D3), would improve bone mineralization in broilers receiving marginally deficient Ca/P diets, with more pronounced effects during malabsorptive coccidiosis. In a 2 VitD source × 2 Ca/P levels × 2 levels of infection factorial experiment (n = 6 pens per treatment, 6 birds/pen), Ross 308 broilers were assigned to an Aviagen-specified diet supplemented with 4,000 IU/kg of either OHD or D3 between days 11 and 24 of age. The diet contained adequate (A; 8.7:4.4 g/kg) or marginally deficient (M; 6.1:3.1 g/kg) total Ca and available (av)P levels. At day 12 of age, birds were inoculated with water (C) or 7,000 Eimeria maxima oocysts (I). Pen performance was measured over 12 days post-infection (pi). One bird per pen was assessed for parameters of bone mineralization and intestinal histomorphometric features (day 6 and 12 pi), as well as E. maxima replication and gross lesions of the small intestine (day 6 pi). There was no interaction between infection status and Ca/avP level on bone mineralization. Bone breaking strength (BS), ash weight (AW), and ash percentage (AP) were highest in broilers fed the OHD-supplemented A diets irrespective of infection status. Eimeria maxima infection impaired (P < 0.05) ADG and FCR pi; Ca and P status at day 6 pi; OHD status, BS, AW, and AP at day 12 pi; and intestinal morphology at day 6 and 12 pi. A- compared to M-fed broilers had higher BS, AW, and AP at day 6 pi, and AW at day 12 pi. VitD source affected only OHD status, being higher (P < 0.001) for OHD- than D3-fed broilers at day 6 and 12 pi. In conclusion, offering OHD and adequate levels of Ca and P improved bone mineralization, with no effect on performance. Dietary D3 and OHD supplemented at 4,000 IU/kg had similar effects on coccidiosis-infected and uninfected broilers, which led to the rejection of our hypothesis.
Idiegberanoise Oikeh; Panagiotis Sakkas; Damer P Blake; Ilias Kyriazakis. Interactions between dietary calcium and phosphorus level, and vitamin D source on bone mineralization, performance, and intestinal morphology of coccidia-infected broilers. Poultry Science 2019, 98, 5679 -5690.
AMA StyleIdiegberanoise Oikeh, Panagiotis Sakkas, Damer P Blake, Ilias Kyriazakis. Interactions between dietary calcium and phosphorus level, and vitamin D source on bone mineralization, performance, and intestinal morphology of coccidia-infected broilers. Poultry Science. 2019; 98 (11):5679-5690.
Chicago/Turabian StyleIdiegberanoise Oikeh; Panagiotis Sakkas; Damer P Blake; Ilias Kyriazakis. 2019. "Interactions between dietary calcium and phosphorus level, and vitamin D source on bone mineralization, performance, and intestinal morphology of coccidia-infected broilers." Poultry Science 98, no. 11: 5679-5690.
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 to assess robustness to challenge, gain greater understanding of organismal biological processes, or deliver individual-targeted treatments or genetic selection. These consequences apply, in particular, to variation in ontogenetic growth. We propose an approach to parameterise mathematical models of individual traits (e.g., reaction norms, growth curves) that address two challenges: 1) Estimation of individual traits while making minimal assumptions about data distribution and correlation, addressed via Approximate Bayesian Computation (a form of nonparametric inference). We are motivated by the fact that available information on distribution of biological data is often less precise than assumed by conventional likelihood functions. 2) Scaling-up to population phenotype distributions while facilitating unbiased use of individual data; this is addressed via a probabilistic framework where population distributions build on separately-inferred individual distributions and individual-trait interpretability is preserved. The approach is tested against Bayesian likelihood-based inference, by fitting weight and energy intake growth models to animal data and normal- and skewed-distributed simulated data. i) Individual inferences were accurate and robust to changes in data distribution and sample size; in particular, median-based predictions were more robust than maximum- likelihood-based curves. These results suggest that the approach gives reliable inferences using few observations and monitoring resources. ii) At the population level, each individual contributed via a specific data distribution, and population phenotype estimates were not disproportionally influenced by outlier individuals. Indices measuring population phenotype variation can be derived for study comparisons. The approach offers an alternative for estimating trait variability in biological systems that may be reliable for various applications, for example, in genetics, health, and individualised nutrition, while using fewer assumptions and fewer empirical observations. In livestock breeding, the potentially greater accuracy of trait estimation (without specification of multitrait variance-covariance parameters) could lead to improved selection and to more decisive estimates of trait heritability.
Joao A.N. Filipe; Ilias Kyriazakis. Bayesian, Likelihood-Free Modelling of Phenotypic Plasticity and Variability in Individuals and Populations. Frontiers in Genetics 2019, 10, 1 .
AMA StyleJoao A.N. Filipe, Ilias Kyriazakis. Bayesian, Likelihood-Free Modelling of Phenotypic Plasticity and Variability in Individuals and Populations. Frontiers in Genetics. 2019; 10 ():1.
Chicago/Turabian StyleJoao A.N. Filipe; Ilias Kyriazakis. 2019. "Bayesian, Likelihood-Free Modelling of Phenotypic Plasticity and Variability in Individuals and Populations." Frontiers in Genetics 10, no. : 1.
Very little has been reported comparing resistance to coccidiosis in fast or slow growing broilers, the latter of which are becoming more prevalent in the broiler industry. We examined mRNA expression in the intestines of fast and slow growing broilers following Eimeria infection. We show that by day 13 post-infection (d pi) with 2500 or 7000 oocysts of Eimeria maxima, slower-growing (Ranger Classic) broilers significantly (P < 0.01) upregulated expression of proinflammatory cyclooxygenase genes (LTB4DH, PTSG1 and PTSG2) above that detected in fast growing (Ross 308) broilers. Expression of CD8α mRNA was downregulated in Ross 308 at day 6d pi with either 2500 or 7000 oocysts of E maxima (P < 0.05), compared to uninfected controls, but was not differentially expressed in Ranger Classic. CD4 genes were not differentially expressed in either chicken line infected with either infectious oocyst dose at d6 pi, compared to uninfected controls. However, at d13 pi, CD4 expression was significantly upregulated in both chicken lines infected with either infectious oocyst dose, compared to uninfected controls (P < 0.05) but this was significantly greater in Ranger Classic broilers compared to Ross 308 (P < 0.05). At d13 pi, expression of CD3 chains (required for T lymphocyte activation) was significantly increased in Ranger Classic compared to Ross 308, infected with either oocyst dose (P < 0.05-0.01). Expression of IL-2 and IL-15 mRNA, required for T lymphocyte proliferation was also significantly upregulated, or maintained longer, in Ranger Classic broilers compared to Ross 308. These differences in immune response to E maxima corresponded with a reduction in E maxima genome detected in the intestines of Ranger Classic compared to Ross 308.
Tim Giles; Panagiotis Sakkas; Aouatif Belkhiri; Paul Barrow; Ilias Kyriazakis; Neil Foster. Differential immune response toEimeria maximainfection in fast‐ and slow‐growing broiler genotypes. Parasite Immunology 2019, 41, e12660 .
AMA StyleTim Giles, Panagiotis Sakkas, Aouatif Belkhiri, Paul Barrow, Ilias Kyriazakis, Neil Foster. Differential immune response toEimeria maximainfection in fast‐ and slow‐growing broiler genotypes. Parasite Immunology. 2019; 41 (9):e12660.
Chicago/Turabian StyleTim Giles; Panagiotis Sakkas; Aouatif Belkhiri; Paul Barrow; Ilias Kyriazakis; Neil Foster. 2019. "Differential immune response toEimeria maximainfection in fast‐ and slow‐growing broiler genotypes." Parasite Immunology 41, no. 9: e12660.
Coccidial infections reduce fat-soluble vitamin status and bone mineralisation in broiler chickens. We hypothesised that broilers infected with Eimeria maxima would benefit from increased dietary supplementation with vitamin D (vitD) or with 25-hydroxycholecalciferol (25(OH)D3 or 25D3). Broilers were assigned to diets with low (L) or commercial (M) vitD levels (25 v. 100 μg/kg) supplemented as cholecalciferol (D3) or 25D3. At day 11 of age, birds were inoculated with water or 7000 E. maxima oocysts. Pen performance was calculated over the early (days 1–6), acute (days 7–10) and recovery periods (days 11–14) post-infection (pi). At the end of each period, six birds per treatment were dissected to assess long bone mineralisation, plasma levels of 25D3, Ca and P, and intestinal histomorphometry. Parasite replication and transcription of cytokines IL-10 and interferon-γ (IFN-γ) were assessed at day 6 pi using quantitative PCR. Performance, bone mineralisation and plasma 25D3 levels were significantly reduced during infection (P < 0·05). M diets or diets with 25D3 raised plasma 25D3, improved performance and mineralisation (P < 0·05). Offering L diets compromised feed efficiency pi, reduced femur breaking strength and plasma P levels at day 10 pi in infected birds (P < 0·05). Contrastingly, offering M diets or diets with 25D3 resulted in higher parasite loads (P < 0·001) and reduced jejunal villi length at day 10 pi (P < 0·01), with no effect on IL-10 or IFN-γ transcription. Diets with M levels or 25D3 improved performance and mineralisation, irrespective of infection, while M levels further improved feed efficiency and mineralisation in the presence of coccidiosis.
Panagiotis Sakkas; Idiegberanoise Oikeh; Damer P. Blake; Sheralyn Smith; Ilias Kyriazakis. Dietary vitamin D improves performance and bone mineralisation, but increases parasite replication and compromises gut health in Eimeria-infected broilers. British Journal of Nutrition 2019, 122, 676 -688.
AMA StylePanagiotis Sakkas, Idiegberanoise Oikeh, Damer P. Blake, Sheralyn Smith, Ilias Kyriazakis. Dietary vitamin D improves performance and bone mineralisation, but increases parasite replication and compromises gut health in Eimeria-infected broilers. British Journal of Nutrition. 2019; 122 (6):676-688.
Chicago/Turabian StylePanagiotis Sakkas; Idiegberanoise Oikeh; Damer P. Blake; Sheralyn Smith; Ilias Kyriazakis. 2019. "Dietary vitamin D improves performance and bone mineralisation, but increases parasite replication and compromises gut health in Eimeria-infected broilers." British Journal of Nutrition 122, no. 6: 676-688.
Disease is a leading cause of diminished welfare and productivity in pig systems, but its spread among pigs within commercial herds can be limited through early detection. Identifying specific behavioral changes at the onset of disease can have a substantial diagnostic value by improving treatment success through timely intervention. Our study aimed to identify key behaviors that visibly change at the group level when only a few individuals are acutely sick. First, we quantified the behavioral changes seen during an acute health challenge in groups of pigs, using total pen vaccination as an artificial sickness model. Then we investigated the minimum proportion of sick pigs needed to detect group level behavioral changes using three treatments: a control (Con; 0% pigs), Low (±20% pigs), or a High (±50% pigs) number of pigs vaccinated in the pens. Total pen vaccination in Trial 1 produced group level behavioral changes, including reduced feeding (P < 0.001), non-nutritive visits to the feeder (NNV; P < 0.01), drinking (P < 0.001), standing (P < 0.001), and interaction with pen enrichment (P < 0.001), accompanied by increased lying rates (P < 0.01) and elevated body temperatures (P < 0.001), confirming that vaccination is an appropriate model to study effects of acute sickness. In Trial 2, group level declines in interaction with the enrichment device (P < 0.001) and standing rates (P = 0.064), along with an increase in pen lying rates (P < 0.001), were apparent in the Low treatment when compared to the Con rates, which suggests these key behaviors could serve an important diagnostic value for early disease detection in groups. These changes lasted for up to 3 h post vaccination. In contrast, feeding rates (treatment × time of day: P < 0.01) only showed a decrease from the Con in the High treatment after vaccination, with pen drinking showing a similar trend (treatment: P = 0.07) suggesting these behaviors would be more appropriate for confirming the spread of disease within a herd. Identifying key behaviors that alert to the presence of disease is critical to further refine automated early warning systems using pen level sensors for commercial pig operations.
Amy L Miller; Hillary A Dalton; Theo Kanellos; Ilias Kyriazakis. How many pigs within a group need to be sick to lead to a diagnostic change in the group’s behavior?1. Journal of Animal Science 2019, 97, 1956 -1966.
AMA StyleAmy L Miller, Hillary A Dalton, Theo Kanellos, Ilias Kyriazakis. How many pigs within a group need to be sick to lead to a diagnostic change in the group’s behavior?1. Journal of Animal Science. 2019; 97 (5):1956-1966.
Chicago/Turabian StyleAmy L Miller; Hillary A Dalton; Theo Kanellos; Ilias Kyriazakis. 2019. "How many pigs within a group need to be sick to lead to a diagnostic change in the group’s behavior?1." Journal of Animal Science 97, no. 5: 1956-1966.
We address the use of accelerometery to automatically monitor lying behaviour in free-farrowing sows; due to their freedom of movement and the consequent increased variety of movements the sows are able to exhibit, the challenges in automating this are greater than in sows housed in movement restricting farrowing environments. The methodology developed was applied to two salient applications: that of farrowing prediction through detection of nest building activity, and comparison of maternal lying behaviour in conventional movement-restricting and free-farrowing systems. Two sensors were attached at both the front and hind end to each of eight periparturient sows. Movement behaviour was recorded for a period of five days around parturition. Activity transitions were classified by a Support Vector Machine classifier, using data from both sensors individually, and combined; classifier output was validated against ground truth annotations collected from video data. We draw conclusions about the benefits of using multiple sensors over a single sensor, as well as the suitability of different sensor locations on the sow. Activity classification was found to improve through the use of multiple sensors, with a mean F1 score (a measure of predictive performance between 0 and 1) of 0.84, compared to use of the front sensor alone (mean F1 = 0.49) and the hind sensor alone (mean F1 = 0.57). Activity transitions were classified using the dual sensor setup with a mean F1 score of 0.77. Using a threshold-based approach, taking transition frequency as an indicator of nesting behaviour, we were able to detect the onset of nest building with an average latency to farrowing of 11.1 (±4.65) hours, and an average of 1 premature detection per sow; however, the majority of these premature were in a particular sow. We draw comparisons between the lying behaviour of free-farrowing and restricted sows. Using a mixed-design ANOVA we found a main effect of farrowing environment on transition duration (p=0.003), peak acceleration (p=0.007) and rate of change in pitch (p=0.009). Improving the classification accuracy of sow activity transitions through the addition of multiple sensors allows for improved performance in applications such as farrowing prediction, which has the capacity to reduce piglet mortality through enabling farrowing supervision. Understanding how movement restriction affects the lying behaviour of farrowing sows has the potential to inform decisions regarding restriction of sows and development of free-farrowing environments.
Robin J. Thompson; Stephen Matthews; Thomas Plötz; Ilias Kyriazakis. Freedom to lie: How farrowing environment affects sow lying behaviour assessment using inertial sensors. Computers and Electronics in Agriculture 2019, 157, 549 -557.
AMA StyleRobin J. Thompson, Stephen Matthews, Thomas Plötz, Ilias Kyriazakis. Freedom to lie: How farrowing environment affects sow lying behaviour assessment using inertial sensors. Computers and Electronics in Agriculture. 2019; 157 ():549-557.
Chicago/Turabian StyleRobin J. Thompson; Stephen Matthews; Thomas Plötz; Ilias Kyriazakis. 2019. "Freedom to lie: How farrowing environment affects sow lying behaviour assessment using inertial sensors." Computers and Electronics in Agriculture 157, no. : 549-557.
We hypothesized that performance and bone mineralization of 2 broiler lines will benefit from increasing vitamin D (vitD) supplementation above current commercial levels and by partial substitution of D3 by 25-OH-D3. Male Ross 308 and 708 chicks (n = 576), were offered diets with low (LD; 1,000), medium (MD; 4,000) or high levels of D3 (HD; 7,000 IU/kg), and medium levels of vitD where the majority of D3 was substituted by 25-OH-D3 (25MD; 1,000 D3+3,000 25-OH-D3 IU/kg). Performance was measured at the end of starter (day 10), grower (day 24), and finisher periods (day 38). Three birds per pen were dissected at the end of each period to assess tibia and femur ash percentage (%), ash weight, bone breaking strength (BBS), and serum levels of 25-OH-D3. Remaining birds were gait scored (GS) at day 37 of age. Genotype and diet did not interact for any trait, whilst performance was not affected by diet. Ross 708 had lower body weight (P < 0.005), higher feed conversion ratio over the grower period (P < 0.05), similar levels of 25-OH-D3, but higher GS (P < 0.05) than Ross 308. Serum 25-OH-D3 levels were affected by diet at the end of the starter and grower periods (P < 0.05), being lowest for LD and highest for 25MD. Diet affected GS (P < 0.01), being higher in LD than 25MD. Femur ash % was higher at the end of the starter and grower periods for 25MD than LD and for both HD and 25MD than LD (P < 0.05). Femur and tibia ash weight were higher for 25MD in comparison to LD birds (P < 0.05) at the end of the grower period. Femur and tibia BBS were higher (P < 0.05) for 25MD in comparison to LD at the end of the grower and finisher periods, respectively. Overall, effects of vitD supply were more pronounced for femur than for tibia mineralization. Results do not suggest supplementation of vitD above current maximum levels and support partial substitution by 25-OH-D3.
P. Sakkas; S. Smith; T.R. Hill; I. Kyriazakis. A reassessment of the vitamin D requirements of modern broiler genotypes. Poultry Science 2019, 98, 330 -340.
AMA StyleP. Sakkas, S. Smith, T.R. Hill, I. Kyriazakis. A reassessment of the vitamin D requirements of modern broiler genotypes. Poultry Science. 2019; 98 (1):330-340.
Chicago/Turabian StyleP. Sakkas; S. Smith; T.R. Hill; I. Kyriazakis. 2019. "A reassessment of the vitamin D requirements of modern broiler genotypes." Poultry Science 98, no. 1: 330-340.
The choice of animal-based traits to identify and deal with production diseases is often a challenge for pig farmers, researchers and other related professionals. This systematic review focused on production diseases, that is, the diseases that arise from management practices, affecting the digestive, locomotory and respiratory system of pigs. The aim was to classify all traits that have been measured and conduct a meta-analysis to quantify the impact of diseases on these traits so that these can be used as indicators for intervention. Data were extracted from 67 peer-reviewed publications selected from 2339 records. Traits were classified as productive (performance and carcass composition), behavioural, biochemical and molecular traits. A meta-analysis based on mixed models was performed on traits assessed more than five times across studies, using the package metafor of the R software. A total of 524 unique traits were recorded 1 to 31 times in a variety of sample material including blood, muscle, articular cartilage, bone or at the level of whole animal. No behavioural traits were recorded from the included experiments. Only 14 traits were measured on more than five occasions across studies. Traits within the biochemical, molecular and productive trait groups were reported most frequently in the published literature and were most affected by production diseases; among these were some cytokines (interleukin (IL) 1-β, IL6, IL8 and tumour necrosis factor-α), acute phase proteins (haptoglobin) and daily weight gain. Quantification of the influence of factors relating to animal characteristics or husbandry practices was not possible, due to the low frequency of reporting throughout the literature. To conclude, this study has permitted a holistic assessment of traits measured in the published literature to study production diseases occurring in various stages of the production cycle of pigs. It shows the lack of consensus and common measurements of traits to characterise production diseases within the scientific literature. Specific traits, most of them relating to performance characteristics or immunological response of pigs, are proposed for further study as potential tools for the prognosis and study of production diseases.
S. Stavrakakis; F. Loisel; P. Sakkas; N. Le Floc’H; Ilias Kyriazakis; G. Stewart; L. Montagne. A systematic literature mapping and meta-analysis of animal-based traits as indicators of production diseases in pigs. Animal 2019, 13, 1508 -1518.
AMA StyleS. Stavrakakis, F. Loisel, P. Sakkas, N. Le Floc’H, Ilias Kyriazakis, G. Stewart, L. Montagne. A systematic literature mapping and meta-analysis of animal-based traits as indicators of production diseases in pigs. Animal. 2019; 13 (7):1508-1518.
Chicago/Turabian StyleS. Stavrakakis; F. Loisel; P. Sakkas; N. Le Floc’H; Ilias Kyriazakis; G. Stewart; L. Montagne. 2019. "A systematic literature mapping and meta-analysis of animal-based traits as indicators of production diseases in pigs." Animal 13, no. 7: 1508-1518.