In test-day (TD) models, records from individual test days are used to determine lactation
production instead of aggregating records. Test-day models have recently gained …

Currently, most analyses of parameters in test-day models involve two types of models:
random regression, where various functions describe variability of (co) variances with regard …

Our data included 119,205 first-parity, test-day records from 15,002 Holsteins in 134 Georgia
farms with temperature and humidity data from 21 weather stations throughout Georgia. The …

Random regression models (RRM) have become common for the analysis of longitudinal
data or repeated records on individuals over time. Applications in animal breeding research …

Recently there has been considerable interest in modeling individual test-day records (TDR)
for genetic evaluation of dairy cattle as a replacement for the traditional use of estimated …

Variance components for weekly averages of daily milk yield were estimated by restricted
maximum likelihood (REML) using a random regression animal model. Additive genetic …

Test-day records of purebred Tsigai, Improved Valachian and Lacaune ewes were analysed
with a general linear model in order to investigate the effects of flock-test day, lactation …

Artificial neural networks (ANNs) have been shown to be a powerful tool for system
modelling in a wide range of applications. In this paper, we focus on the capability of ANNs …

Lactation persistency, often simply called persistency, in general can be defined as the
ability to maintain yields during the lactation. Persistency has an impact on food costs …

Covariance matrices and genetic parameters for milk production traits in sheep were
estimated for the Improved Valachian and Tsigai breeds. These multipurpose breeds are of …