Emotional responses of piglets under long-term exposure to negative and positive auditory stimuli

The stress caused by sound is inevitable. The stress caused by noise and the positive effects of music can affect the endocrine of animals and their welfare. In this study, a total of 72 hybrid piglets (Large White × Duroc × Min pig) were randomly divided into 3 groups, including music (Mozart K.448, 60-70 dB), noise (recorded mechanical noise, 80-85 dB), and control (natural background sound, <40 dB) groups. S-IgA (secretory immunoglobulin A), IL-6 (interleukin-6), IL-8 (interleukin-8), and positive emotion-related behaviors were used as indicators to discuss whether noise induced stress and inflammation in piglets or whether music could have positive effects. Six hours of auditory exposure were given daily (10:00-16:00), which lasted for 56 days. Behavioral responses of the piglets were observed, and the concentrations of salivary S-IgA and serum IL-6 and IL-8 were measured. The results showed that the concentration of S-IgA increased in the noise and control groups on the 57th day (P < 0.05); S-IgA concentration in the music group was unchanged after long-term music exposure. The concentrations of IL-6 and IL-8 showed that long-term noise exposure might lead to stress and inflammation in piglets. Tail-wagging and play behaviors of the piglets in the music group were significantly greater than those in the noise and control groups, which implied that long-term music exposure improved the emotional state of the piglets in a restricted and barren environment.

[Development and performance test of the environment scale of unintentional injury in the home for children aged 0-6 years old in urban area of China]

Objective: To develop the environment scale of unintentional injury in the home for children aged 0-6 years living in urban area of China, and test its validity and reliability. Methods: The content of the environment scale was established through the literature review, expert consultation and pilot study. A total of 1 104 children aged 0-6 years in urban area of Changsha were enrolled in this study by using a multi-stage stratified cluster random sampling method. The questionnaire was used to collect the basic information of children, the incidence of unintentional injury and the status of home environment. The reliability of the scale was tested by using Cronbach's α coefficient and split-half reliability coefficient. The content validity and construct validity were tested by using Pearson correlation analysis and factor analysis. All children were divided into two groups according to the incidence of unintentional injury in the home and the discrimination validity of the scale was tested by using t-test. Results: The scale had 54 items in 6 dimensions. The number of eligible questionnaires was 1 074, including 554 (51.6%) from boys and 519 (48.3%) from children under 3 years old. The incidence rate of unintentional injury and in-home injury was 18.34% (197 children) and 10.71% (115 children). The internal consistency reliability (Cronbach's α) coefficient for the scale was 0.87 and the split-efficacy reliability coefficient was 0.82, both meeting the standard of reliability above 0.70. The Pearson correlation coefficient between each dimension and the whole scale ranged from 0.53 to 0.84 (all P values <0.001). The common factor cumulative variance contribution rate of the scale was 58.34%. There were 54 items with factor loadings greater than 0.30. The root mean square error of approximation, comparative fit index and goodness-of-fit index were 0.07, 0.61 and 0.71, respectively. The score of scale in children with injury was significantly higher than that in children without injury (P=0.022). Conclusion: The validity and reliability of the environment scale for unintentional injury in the home for children aged 0-6 years old in the urban area of China are good.