This experiment was conducted to determine the association between several risk factors which may affect culling of the Iranian Holstein cows. The data consisted of 329,772 lactation records collected by the Animal Breeding Center of Iran (2003 to 2012).The logistic regression was applied to investigate the associations between the response variable, the risk of culling, and predictor variables...

The effect of calving ease on the fertility and production performance of both dam and calf was studied in approximately 50,000 and 10,000 UK Holstein-Friesian heifers and heifer calves, respectively. The first objective of this study was to estimate the effect of a difficult calving on the subsequent first-lactation milk production by estimating lactation curves using cubic splines. This metho...

New maternal breeding values have been developed for use in UK beef evaluations. To undertake multitrait BLUP evaluations, it is necessary to have a full covariance matrix. This study outlines the approach taken to construct the full covariance matrices for the four beef breeds that most widely contribute to suckler beef cows in the United Kingdom. The maternal traits investigated were age at f...

Context An ability to predict calving difficulty could help farmers make better farm-management decisions, thereby improving dairy farm profitability and welfare.Aims This study aimed in Iranian herds using machine-learning (ML) algorithms evaluate sampling methods deal with imbalanced datasets.Methods For this purpose, the history records of cows that calved between 2011 2021 on two commercial...

In this study, the detection of dairy cows with difficult calvings using artificial neural networks (ANN) and classification functions (CF) is presented. The set of 15 classification variables was used. The dependent variable was the class of calving difficulty: difficult or easy. Perceptrons with one (MLP1) and two (MLP2) hidden layers as well as radial basis function (RBF) networks were analy...

There is considerable concern about the consequences on fitness-related traits of using narrow breeding objectives for production traits. The aim of this study was to assess the potential consequences of selection for growth in French beef cattle breeds by estimating genetic correlations between growth, reproduction, calving and suckling traits of Charolais, Limousin and Blonde d’Aquitaine heif...

Two trials were conducted to evaluate effects of Synovex C implants on replacement heifers, given at two different ages. Crossbred heifer calves (n = 370) were allotted to four treatments: 1) nonimplanted controls, 2) implanted at 2 mo, 3) implanted at 6 mo, and 4) implanted at both 2 and 6 mo of age. Heifers implanted at 2 mo gained 7 kg more (P = .01) by 6 mo than those not implanted at 2 mo....