The aim of the study was to investigate effect of transport times of up to 12 h on pigs＇ welfare. An observation box was located on the 3rd floor of the vehicle. Device to measure temperature, humidity and video came...The aim of the study was to investigate effect of transport times of up to 12 h on pigs＇ welfare. An observation box was located on the 3rd floor of the vehicle. Device to measure temperature, humidity and video camera to monitor pigs＇ behaviors were fitted in the box. Eighteen measurements were performed during two seasons for 4, 8, and 12 h of transport time with three replications. Meat samples were taken from longissimus dorsi （LD） and the carcases were chilled for 24 h at ＋4 ~C for pH determination. To determine cortisol, glucose, lactate, and creatine kinase concentration levels, blood samples were collected before and after transport from 90 pigs and from 20 controls that were not transported for control purposes. To evaluate behavioural alterations, frequency of events and durations were considered. Highest pH24 of 5.99 ＋ 0.29 occurred during summer at 12 h transport time. Cortisol concentrations elevated during short and decreased with an increase of transport time （P 〈 0.001）. Highest and lowest glucose concentrations for winter and summer were at 8 and 12 h transport time, respectively （P 〈 0.01）. Concentrations of lactate and creatine kinase positively correlated with transport time （P 〈 0.002）. Lying, sitting, rooting and vocalization behaviours correlated with transport time （P 〈 0.009）. Certain THI values during summer surpassed normal （〉 74） level during loading. The pH24 value correlated with transport time during summer. Lactate and creatine kinase concentrations increased with an increase in transport time but for Glucose, highest value was at 8 h transport time.展开更多
Social challenges from rival conspecifics are common in the lives of animals, and changes in an animal＇s social environment can influence physiology and behavior in ways that appear to be adaptive in the face of cont...Social challenges from rival conspecifics are common in the lives of animals, and changes in an animal＇s social environment can influence physiology and behavior in ways that appear to be adaptive in the face of continued social instability （i.e. social priming）. Recently, it has become clear that testosterone, long thought to be the primary mediator of these effects, may not always change in response to social challenges, an observation that highlights gaps in our understanding of the proximate me- chanisms by which animals respond to their social environment. Here, our goal is to address the degree to which testosterone me- diates organismal responses to social cues. To this end, we review the behavioral and physiological consequences of social chal- lenges, as well as their underlying hormonal and gene regulatory mechanisms. We also present a new case study from a wild songbird, the dark-eyed junco Junco hyemalis, in which we find largely divergent genome-wide transcriptional changes induced by social challenges and testosterone, respectively, in muscle and liver tissue. Our review underscores the diversity of mechani- sms that link the dynamic social environment with an organisms＇ genomic, hormonal, and behavioral state. This diversity among species, and even among tissues within an organism, reveals new insights into the pattern and process by which evolution may alter proximate mechanisms of social priming.展开更多
Phenotypic plasticity is nearly universal among organisms, and evidence indicates that plasticity can exhibit additive genetic variation and respond to selection. These findings have important implications for our und...Phenotypic plasticity is nearly universal among organisms, and evidence indicates that plasticity can exhibit additive genetic variation and respond to selection. These findings have important implications for our understanding of how plasticity may be constrained and how its mechanistic structure may affect its evolution. Many life history trade-offs may be conceptua- lized as plastic traits, with individuals varying in their position along trade-off axes due to genetic differences, developmental plasticity, or short-term plasticity occurring throughout an individual＇s lifetime. Behavioral plasticity is key to understanding when organisms are likely to encounter trade-offs, whether those trade-offs can be mitigated, and how the tradc-offs affect the ecology and evolution of populations. In this review, we discuss hormonal and neural mechanisms that may influence how plastic behavioral traits are expressed and evolve. We also outline a classification of life history trade-offs and their mechanistic bases and discuss the currencies most likely to mediate each category of trade-off and bow they are tied to the mechanisms by which animals express their behaviors.展开更多
文摘The aim of the study was to investigate effect of transport times of up to 12 h on pigs＇ welfare. An observation box was located on the 3rd floor of the vehicle. Device to measure temperature, humidity and video camera to monitor pigs＇ behaviors were fitted in the box. Eighteen measurements were performed during two seasons for 4, 8, and 12 h of transport time with three replications. Meat samples were taken from longissimus dorsi （LD） and the carcases were chilled for 24 h at ＋4 ~C for pH determination. To determine cortisol, glucose, lactate, and creatine kinase concentration levels, blood samples were collected before and after transport from 90 pigs and from 20 controls that were not transported for control purposes. To evaluate behavioural alterations, frequency of events and durations were considered. Highest pH24 of 5.99 ＋ 0.29 occurred during summer at 12 h transport time. Cortisol concentrations elevated during short and decreased with an increase of transport time （P 〈 0.001）. Highest and lowest glucose concentrations for winter and summer were at 8 and 12 h transport time, respectively （P 〈 0.01）. Concentrations of lactate and creatine kinase positively correlated with transport time （P 〈 0.002）. Lying, sitting, rooting and vocalization behaviours correlated with transport time （P 〈 0.009）. Certain THI values during summer surpassed normal （〉 74） level during loading. The pH24 value correlated with transport time during summer. Lactate and creatine kinase concentrations increased with an increase in transport time but for Glucose, highest value was at 8 h transport time.
文摘Social challenges from rival conspecifics are common in the lives of animals, and changes in an animal＇s social environment can influence physiology and behavior in ways that appear to be adaptive in the face of continued social instability （i.e. social priming）. Recently, it has become clear that testosterone, long thought to be the primary mediator of these effects, may not always change in response to social challenges, an observation that highlights gaps in our understanding of the proximate me- chanisms by which animals respond to their social environment. Here, our goal is to address the degree to which testosterone me- diates organismal responses to social cues. To this end, we review the behavioral and physiological consequences of social chal- lenges, as well as their underlying hormonal and gene regulatory mechanisms. We also present a new case study from a wild songbird, the dark-eyed junco Junco hyemalis, in which we find largely divergent genome-wide transcriptional changes induced by social challenges and testosterone, respectively, in muscle and liver tissue. Our review underscores the diversity of mechani- sms that link the dynamic social environment with an organisms＇ genomic, hormonal, and behavioral state. This diversity among species, and even among tissues within an organism, reveals new insights into the pattern and process by which evolution may alter proximate mechanisms of social priming.
文摘Phenotypic plasticity is nearly universal among organisms, and evidence indicates that plasticity can exhibit additive genetic variation and respond to selection. These findings have important implications for our understanding of how plasticity may be constrained and how its mechanistic structure may affect its evolution. Many life history trade-offs may be conceptua- lized as plastic traits, with individuals varying in their position along trade-off axes due to genetic differences, developmental plasticity, or short-term plasticity occurring throughout an individual＇s lifetime. Behavioral plasticity is key to understanding when organisms are likely to encounter trade-offs, whether those trade-offs can be mitigated, and how the tradc-offs affect the ecology and evolution of populations. In this review, we discuss hormonal and neural mechanisms that may influence how plastic behavioral traits are expressed and evolve. We also outline a classification of life history trade-offs and their mechanistic bases and discuss the currencies most likely to mediate each category of trade-off and bow they are tied to the mechanisms by which animals express their behaviors.
