Review: Placental physiology and fetal programming in ruminants under heat stress.

The placenta plays a crucial role in transferring nutrients and oxygen between the dam and fetus during pregnancy. It is highly influenced by environmental conditions, especially stressors such as heat and nutritional deficiencies, which can significantly impact the fetus's long-term health and development. Cattle, especially dairy cows, commonly experience stress during late gestation, which can lead to changes in behavior and physiology, affecting both subsequent milk production and fetal development.

A metastasis-associated pannexin-1 mutant (Panx1) forms a minimalist ATP release channel.

A truncated form of the ATP release channel pannexin 1 (Panx1), Panx1, is enriched in metastatic breast cancer cells and has been proposed to mediate metastatic cell survival by increasing ATP release through mechanosensitive Panx1 channels. However, whether Panx1 on its own [without the presence of wild-type Panx1 (wtPanx1)] mediates ATP release has not been tested. Here, we show that Panx1 by itself can form a constitutively active membrane channel, capable of releasing ATP even in the absence of wtPanx1.

Late gestation heat stress alters O regulation in placenta and neonatal heifers.

Introduction: Maternal hyperthermia (i.e. heat stress) can adversely affect placental development and function, with severity varying based on pregnancy stage.

Late-gestation heat stress alters placental structure and function in multiparous dairy cows.

The placenta plays a pivotal role in fetal development and the dam's subsequent lactation performance, because it facilitates nutrient transfer, heat dissipation, and gas exchange with the growing fetus, and regulates key hormones essential for mammary gland development. Heat stress experienced during gestation and lactation can significantly reduce the placenta's capacity to perform these critical functions. To investigate the impact of heat stress, trials were conducted over the summer months of 2020, 2022, and 2023 in Florida.

Effect of a nutritional immunomodulator in dry cows heat stressed with an electric blanket model.

Heat stress in the dry period reduces yield and health in the next lactation. Previous work indicates that feeding OmniGen AF (OMN; Phibro Animal Health) mitigates the detrimental effects of heat stress. Electric blankets (EB) can induce heat stress in lactating cows, but EB have not been used with dry cows.