Genetic and genomic analysis of oxygen consumption in mice

Effect of ambient temperature on average daily gain of pigs evaluated using public weather data and a plateau-linear regression model

We performed a plateau-linear regression model analysis of the average daily gain (ADG) of pigs on daily average temperature at the end of performance testing (T). Records for performance testing between 30 kg and 105 kg of 2268 purebred Duroc pigs raised at the National Livestock Breeding Center Miyazaki Station were used. Off-farm ambient temperatures were measured at the nearest Automated Meteorological Data Acquisition System station at Kobayashi, Miyazaki (Kobayashi station). A plateau-linear regression equation was obtained in which ADG decreased by 12.6 g for every 1°C when T > 21.1°C. We calculated the expected age in day at the end of testing (D105) using the regression equation obtained and T observed at the Kobayashi station in 2020. The number of days that D105 was prolonged due to higher T was 125 days, corresponding to approximately one third of the year. These results could contribute to planning and management of stable pork production in response to heat in Japan.

Myeloperoxidase expression in diencephalon is potentially associated with fear‐related behavior in chicks of laying hen

Preventing feather pecking (FP) in adult laying hens is important for the welfare of intensively poultry farming. Fear-related behavior in growing female layer chicks may predict FP in adult hens. In this study, in two representative laying breeds (White Leghorn [WL] and Rhode Island Red [RIR]) that have different FP frequencies, we identified a candidate gene associated with fear-related behavior in chicks and FP in adult hens. In the tonic immobility test and open-field test, the behavioral activity was lower in WL chicks than in RIR chicks (P < 0.01), suggesting that WL chicks were more fearful than RIR chicks. Based on previous studies, 51 genes that have been found to be differentially expressed in the brain between high- and low-FP populations were chosen, and their expression levels were screened in the chick diencephalon. This analysis revealed that myeloperoxidase (MPO) gene expression level was higher in WL chicks than that in RIR chicks (P < 0.05). Furthermore, STRING analysis predicted the gene network including MPO and MPO-related genes and revealed the association of these genes with fear-related behavior. These results suggest that MPO is potentially associated with fear-related behavior in growing female layer chicks and FP in adult hens.