Bovine mammary epithelial (MAC-T) cells are commonly used to study mammary gland development and mastitis. Lipopolysaccharide is a major bacterial cell membrane component that can induce inflammation. Autophagy is an important regulatory mechanism participating in the elimination of invading pathogens. In this study, we evaluated the mechanism underlying bacterial mastitis and mammary cell death following lipopolysaccharide treatment. After 24 h of 50 μg/mL lipopolysaccharide treatment, a significant decrease in the proliferation rate of MAC-T cells was observed. However, no changes were observed upon treatment of MAC-T cells with 10 μg/mL of lipopolysaccharide for up to 48 h. Thus, upon lipopolysaccharide treatment, MAC-T cells exhibit dose-dependent effects of growth inhibition at 10 μg/mL and death at 50 μg/mL. Treatment of MAC-T cells with 50 μg/mL lipopolysaccharide also induced the expression of autophagy-related genes ATG3, ATG5, ATG10, ATG12, MAP1LC3B, GABARAP-L2, and BECN1. The autophagy-related LC3A/B protein was also expressed in a dose-dependent manner upon lipopolysaccharide treatment. Based on these results, we suggest that a high dose of bacterial infection induces mammary epithelial cell death related to autophagy signals.

South Korea has a temperate climate with four distinct seasons. However, summers are extremely hot and humid, which negatively affects industrial animal production. Hanwoo are native cattle that have traditionally been raised in the natural environment of Korea. The present study investigated the effects of birth and lactation season on the birth and weaning weights of Hanwoo calves. Data were collected from 100 local breeding farms between 2016 and 2021. A total of 56,970 (males, 29,530; females, 27,440) Hanwoo calves were classified according to sex or birth and weaning season (March-May, spring; June-August, summer; September-November, fall; and December-February, winter). The birth weight of Hanwoo calves differed according to the birth season. As such, birth weight of the summer-born calves was the lowest. Additionally, the 90-day weaning weight was positively correlated with birth weight. Interestingly, however, the 90-day weaning weight was not related to the birth season but was related to the 2-month seasonal effect during the lactation period. Furthermore, the 90-day weaning weight was the lowest during the summer lactation period. In the beef cattle industry, daily weight gain is an important economic characteristic related to feed efficiency and growth. Our findings will contribute the management of Hanwoo cattle and analysis of changes in economic characteristics due to high temperatures.

South Korean summers are hot and humid, negatively affecting the pig industry. This study investigated the effects of season on farrowing rate, litter size, litter per sow per year, and piglets per sow per year on pig farms. The data were collected from local pig farms in Jeongeup-si, South Korea. The four seasons were classified as spring (March-May), summer (June-August), fall (September-November), and winter (December-February). The temperatures of the farrowing houses in summer differed for each of the four pig farms analyzed. Farm 1 and farm 2 regulated their temperatures. In contrast, farm 3 and farm 4 did not control their temperatures. Consequently, the pig production efficiency of farm 1 and farm 2 did not differ between the four seasons. Although the farrowing rate and litter size did not differ with the season, the number of weaning piglets was significantly reduced in the summer on farm 3 and farm 4. In farm 3, the farrowing interval was significantly increased, and the litter per sow per year was the highest in winter. In addition, the litter per sow per year was significantly lower in the summer at farm 4. Furthermore, the number of piglets per sow per year was significantly reduced in the summer at farm 3 and farm 4. These data indicate that the thermoregulation of farrowing houses during the summer is important for efficient pig production in Korea.