Background: Post-weaning diarrhoea (PWD) is a significant gastrointestinal disease in pigs. It is... more Background: Post-weaning diarrhoea (PWD) is a significant gastrointestinal disease in pigs. It is considered a multifactorial disease associated with proliferation of enterotoxigenic Escherichia coli in the intestinal tract of affected pigs. The aim of this study was to analyse risk factors related to the occurrence of PWD on Finnish piglet producing farms.
ABSTRACT The oxygen consumption of adult burbot, Lota lota (L.), was examined to determine the ef... more ABSTRACT The oxygen consumption of adult burbot, Lota lota (L.), was examined to determine the effects of fasting and meal ration on oxygen consumption rates. The temperature (2.1 °C) was selected to represent ambient conditions for burbot in winter. The average pre-feeding oxygen consumption rate was 29.5 mg kg-1 h-1. Feeding affected the oxygen consumption rates since the apparent heat increment correlated significantly with the meal ration. However, the meal ration (i.e. vendace, Coregonus albula L.) did not affect the proportion of the ingested meal energy used in the apparent heat increment. When the meal ration was increased, peak oxygen consumption ranged from 1.2 to 2.2 times higher than the fasting level. Observed low oxygen consumption values suggest that the metabolic processes of burbot are strongly reduced in low temperatures.
Underyearling Lake Inari Arctic charr Salvelinus alpinus were acclimated to 11·0 C for 3 weeks, a... more Underyearling Lake Inari Arctic charr Salvelinus alpinus were acclimated to 11·0 C for 3 weeks, and then one group was maintained at 11·0 C and others were exposed to 14·4 C const , 17·7 C const or a diel fluctuating temperature of 14·3 C 1 C (14·3 C fluc ). Routine rates of oxygen consumption and ammonia excretion were measured over 10 days before the temperature change and over 31 days following the change. Measurements were made on fish that were feeding and growing. The temperature increase produced an immediate increase in oxygen consumption. There was then a decline over the next few days, suggesting that thermal acclimation was rapid. For groups exposed to constant temperature there was an increase in oxygen consumption (M accl , mg kg 1 h 1 ) with increasing temperature (T), the relationship being approximated by an exponential model: M accl =46·53e 0·086T . At 14·3 C fluc oxygen consumption declined during the 3-4 days following the temperature shift, but remained higher than at 14·4 C const . This indicates that small temperature fluctuations have some additional influences that increase metabolic rate. Ammonia excretion rates showed diel variations. Excretion was lower at 11 C const than at other temperatures, and increases in temperature had a significant effect on ammonia excretion rate. Fluctuating (14·3 C fluc ) temperature did not influence ammonia excretion relative to constant temperature (14·4 C const ). 1998 The Fisheries Society of the British Isles
Underyearling Arctic charr were acclimated to six temperatures between 6 and 21·5 C and thermal t... more Underyearling Arctic charr were acclimated to six temperatures between 6 and 21·5 C and thermal tolerance and resistance were tested after an acclimation period of at least 2 weeks. Resistance times were influenced by acclimation temperature and the highest upper incipient lethal temperature was 23-24 C. An upper limit for cultivation of Lake Inari charr is suggested to be 21 C which is the intercept of the function which represents the upper limit of the thermal tolerance zone. 1997 The Fisheries Society of the British Isles
ABSTRACT The oxygen consumption of adult burbot, Lota lota (L.), was examined to determine the ef... more ABSTRACT The oxygen consumption of adult burbot, Lota lota (L.), was examined to determine the effects of fasting and meal ration on oxygen consumption rates. The temperature (2.1 °C) was selected to represent ambient conditions for burbot in winter. The average pre-feeding oxygen consumption rate was 29.5 mg kg-1 h-1. Feeding affected the oxygen consumption rates since the apparent heat increment correlated significantly with the meal ration. However, the meal ration (i.e. vendace, Coregonus albula L.) did not affect the proportion of the ingested meal energy used in the apparent heat increment. When the meal ration was increased, peak oxygen consumption ranged from 1.2 to 2.2 times higher than the fasting level. Observed low oxygen consumption values suggest that the metabolic processes of burbot are strongly reduced in low temperatures.
Rapid structural change and concentration of pig production in regions with most intensive produc... more Rapid structural change and concentration of pig production in regions with most intensive production has raised concerns about whether the risk of large-scale disease losses has increased in Finland. This paper examines the pig industry's losses due to classical swine fever (CSF) epidemics. The work is based on economic and epidemiological models providing insights to the consequences of epidemics to infected and uninfected farms, government and meat processing. The economic analysis was carried out by use of a sector model, which simulated the recovery of pig production, starting from the recognition of the disease in the country and ending at a steady-state market equilibrium about 12 years later. The model explicitly took into account profit-maximising behaviour of producers and the effects of decrease in export demand.
2 Risk classification of livestock farms can help stakeholders design and implement risk manageme... more 2 Risk classification of livestock farms can help stakeholders design and implement risk management measures according to the possessed risk. Our goal is to examine how differently pig farms may contribute to the societal costs of an animal disease outbreak, how valuable this information is to different stakeholders, and how it can be used to target risk management measures. We show that the costs of an outbreak starting from a certain farm can be quantified for the entire sector using bio-economic models. In further studies, this quantified risk can be differentiated so that farms and slaughterhouses internalise the full cost of risk in production decisions and inhibit animal densities, animal contact structures or other characteristics which pose a threat to the sector.
Increasing farm size and regional concentration of pig production have raised questions on whethe... more Increasing farm size and regional concentration of pig production have raised questions on whether the potential costs of animal disease epidemics have in- creased. The goal of this study was to estimate how large classical swine fever losses could be if the disease were introduced into, and detected in Finland. Furthermore, the goal was to study which factors would cause
Background: Post-weaning diarrhoea (PWD) is a significant gastrointestinal disease in pigs. It is... more Background: Post-weaning diarrhoea (PWD) is a significant gastrointestinal disease in pigs. It is considered a multifactorial disease associated with proliferation of enterotoxigenic Escherichia coli in the intestinal tract of affected pigs. The aim of this study was to analyse risk factors related to the occurrence of PWD on Finnish piglet producing farms.
ABSTRACT The oxygen consumption of adult burbot, Lota lota (L.), was examined to determine the ef... more ABSTRACT The oxygen consumption of adult burbot, Lota lota (L.), was examined to determine the effects of fasting and meal ration on oxygen consumption rates. The temperature (2.1 °C) was selected to represent ambient conditions for burbot in winter. The average pre-feeding oxygen consumption rate was 29.5 mg kg-1 h-1. Feeding affected the oxygen consumption rates since the apparent heat increment correlated significantly with the meal ration. However, the meal ration (i.e. vendace, Coregonus albula L.) did not affect the proportion of the ingested meal energy used in the apparent heat increment. When the meal ration was increased, peak oxygen consumption ranged from 1.2 to 2.2 times higher than the fasting level. Observed low oxygen consumption values suggest that the metabolic processes of burbot are strongly reduced in low temperatures.
Underyearling Lake Inari Arctic charr Salvelinus alpinus were acclimated to 11·0 C for 3 weeks, a... more Underyearling Lake Inari Arctic charr Salvelinus alpinus were acclimated to 11·0 C for 3 weeks, and then one group was maintained at 11·0 C and others were exposed to 14·4 C const , 17·7 C const or a diel fluctuating temperature of 14·3 C 1 C (14·3 C fluc ). Routine rates of oxygen consumption and ammonia excretion were measured over 10 days before the temperature change and over 31 days following the change. Measurements were made on fish that were feeding and growing. The temperature increase produced an immediate increase in oxygen consumption. There was then a decline over the next few days, suggesting that thermal acclimation was rapid. For groups exposed to constant temperature there was an increase in oxygen consumption (M accl , mg kg 1 h 1 ) with increasing temperature (T), the relationship being approximated by an exponential model: M accl =46·53e 0·086T . At 14·3 C fluc oxygen consumption declined during the 3-4 days following the temperature shift, but remained higher than at 14·4 C const . This indicates that small temperature fluctuations have some additional influences that increase metabolic rate. Ammonia excretion rates showed diel variations. Excretion was lower at 11 C const than at other temperatures, and increases in temperature had a significant effect on ammonia excretion rate. Fluctuating (14·3 C fluc ) temperature did not influence ammonia excretion relative to constant temperature (14·4 C const ). 1998 The Fisheries Society of the British Isles
Underyearling Arctic charr were acclimated to six temperatures between 6 and 21·5 C and thermal t... more Underyearling Arctic charr were acclimated to six temperatures between 6 and 21·5 C and thermal tolerance and resistance were tested after an acclimation period of at least 2 weeks. Resistance times were influenced by acclimation temperature and the highest upper incipient lethal temperature was 23-24 C. An upper limit for cultivation of Lake Inari charr is suggested to be 21 C which is the intercept of the function which represents the upper limit of the thermal tolerance zone. 1997 The Fisheries Society of the British Isles
ABSTRACT The oxygen consumption of adult burbot, Lota lota (L.), was examined to determine the ef... more ABSTRACT The oxygen consumption of adult burbot, Lota lota (L.), was examined to determine the effects of fasting and meal ration on oxygen consumption rates. The temperature (2.1 °C) was selected to represent ambient conditions for burbot in winter. The average pre-feeding oxygen consumption rate was 29.5 mg kg-1 h-1. Feeding affected the oxygen consumption rates since the apparent heat increment correlated significantly with the meal ration. However, the meal ration (i.e. vendace, Coregonus albula L.) did not affect the proportion of the ingested meal energy used in the apparent heat increment. When the meal ration was increased, peak oxygen consumption ranged from 1.2 to 2.2 times higher than the fasting level. Observed low oxygen consumption values suggest that the metabolic processes of burbot are strongly reduced in low temperatures.
Rapid structural change and concentration of pig production in regions with most intensive produc... more Rapid structural change and concentration of pig production in regions with most intensive production has raised concerns about whether the risk of large-scale disease losses has increased in Finland. This paper examines the pig industry's losses due to classical swine fever (CSF) epidemics. The work is based on economic and epidemiological models providing insights to the consequences of epidemics to infected and uninfected farms, government and meat processing. The economic analysis was carried out by use of a sector model, which simulated the recovery of pig production, starting from the recognition of the disease in the country and ending at a steady-state market equilibrium about 12 years later. The model explicitly took into account profit-maximising behaviour of producers and the effects of decrease in export demand.
2 Risk classification of livestock farms can help stakeholders design and implement risk manageme... more 2 Risk classification of livestock farms can help stakeholders design and implement risk management measures according to the possessed risk. Our goal is to examine how differently pig farms may contribute to the societal costs of an animal disease outbreak, how valuable this information is to different stakeholders, and how it can be used to target risk management measures. We show that the costs of an outbreak starting from a certain farm can be quantified for the entire sector using bio-economic models. In further studies, this quantified risk can be differentiated so that farms and slaughterhouses internalise the full cost of risk in production decisions and inhibit animal densities, animal contact structures or other characteristics which pose a threat to the sector.
Increasing farm size and regional concentration of pig production have raised questions on whethe... more Increasing farm size and regional concentration of pig production have raised questions on whether the potential costs of animal disease epidemics have in- creased. The goal of this study was to estimate how large classical swine fever losses could be if the disease were introduced into, and detected in Finland. Furthermore, the goal was to study which factors would cause
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Papers by T. Lyytikainen