Epidemiological and genetic factors affecting severe epizootic hemorrhagic disease in Spanish Holstein cattle during the Southern Europe outbreak of 2023.

Epizootic hemorrhagic disease (EHD) is a non-contagious viral infection that can cause important economic losses in dairy farms. This study aimed to identify epidemiological and genetic factors influencing the susceptibility and severity of EHD in Holstein dairy cattle during the 2023 outbreak in Spain. Data from 2852 animals in 7 affected farms from 5 Spanish provinces were used.

Modelling heat stress effects on milk production traits in Tunisian Holsteins using a random regression approach.

This study investigated the impact of temperature and humidity on milk production traits in Tunisian dairy cows, analysing population-level trends and individual cow responses using various modelling techniques and heat stress (HS) indices. Two distinct datasets were used for this purpose: the first included 551,139; 331,654 and 302,396 test-day records for milk, fat and protein yields, respectively. The second supplemented the production information with daily average (THIavg) and maximum (THImax) temperature-humidity index (THI) data.

Stress-induced epigenetic effects driven by maternal lactation in dairy cattle: a comethylation network approach.

Epigenetic marks do not follow the Mendelian laws of inheritance. The environment can alter the epigenotype of an individual when exposed to different external stressors. In lactating cows, the first stages of gestation overlap with the lactation peak, creating a negative energy balance that is difficult to overcome with diet.

Genome-Wide Association Study Reveals Quantitative Trait Loci and Candidate Genes Associated with High Interferon-gamma Production in Holstein Cattle Naturally Infected with .

() is the causative agent of bovine tuberculosis (bTb). Genetic selection aiming to identify less susceptible animals has been proposed as a complementary measure in ongoing programs toward controlling infection. However, individual animal phenotypes for bTb based on interferon-gamma (IFNɣ) and its use in bovine selective breeding programs have not been explored.

Ruminal microbiome changes across lactation in primiparous Holstein cows with varying methane intensity: Heritability assessment.

Methane is a potent greenhouse gas produced during the ruminal fermentation and is associated with a loss of feed energy. Therefore, efforts to reduce methane emissions have been ongoing in the last decades. Methane production is highly influenced by factors such as the ruminal microbiome and host genetics.