Genetic evaluation of udder health traits in Spanish Holstein cows.

The aims of this study were to estimate the genetic parameters of clinical mastitis (CM) and SCS traits, and to compare the performance of genetic evaluations of CM traits using univariate and bivariate analyses (CM-SCS). Data were edited according to the Udder Health Golden Standard harmonization, and then 6 CM traits and 6 SCS traits were considered, as the result of combining 3 lactation classifications (1, 2, ≥3) and 2 milking periods (early, late). The linear mixed animal models included the ratio of period at risk as a covariate, herd-year of calving, month of calving, and lactation-age as fixed effects, and the permanent environmental effect for traits of ≥3 lactations.

Association between days open and milk spectral data in dairy cows.

Data on 19,489 Brown Swiss cows reared in northeastern Italy were used to associate absorbances of individual wavenumbers within the mid-infrared range with days open (DO). Different postcalving days in milk (DIM) intervals were studied to determine the most informative milk sampling periods for predicting DO. Milk samples were analyzed using a MilkoScan (Foss Electric, Hillerød, Denmark) Fourier-transform infrared (FTIR) spectrometer for 1,060 wavenumbers (wn) ranging from 5,011 to 925 cm.

Influence of age at first calving in a continuous calving season on productive, functional, and economic performance in a Blonde d'Aquitaine beef population.

The lifetime production of 7,655 cows with known age at first calving and a total of 27,118 parity records from 301 purebred Blonde d'Aquitaine herds were used to demonstrate the economic benefits of 2 yr of age at first calving. Ages at first calving ranged from 20 to 48 mo, and cows were divided into 5 calving groups, starting with early calving from age 20 to 27 mo up to late calving from age 40 to 48 mo. The information was gathered into 2 data sets, one for only primiparous cows and the second for all cows.

Effect of claw disorders on milk production, fertility, and longevity, and their economic impact in Spanish Holstein cows.

The aims of this study were (1) to estimate the phenotypic association between different degrees of severity of claw disorders and production, fertility performance, and longevity in Spanish dairy cattle, and (2) to quantify its economic impact at the animal and herd level. In this study, claw data comprised 108,468 trimmings collected between 2012 and 2014 by 25 trimmers from 804 Holstein dairy herds. The claw disorders considered were the 3 most frequent disorders in Spanish dairy herds: dermatitis (DE), sole ulcer (SU), and white line disease (WL).

Short communication: Association of foot and leg conformation and body weight with claw disorders in Spanish Holstein cows.

Data of first-lactation Holstein cows including claw disorders, foot and leg type traits, and structure and capacity type traits were used to study the phenotypic association of conformation and body weight with claw health status. The claw disorders studied were digital and interdigital dermatitis, sole ulcer, white line disease, and an overall claw disorder trait, indicating the presence of any of the 6 claw disorders recorded by the Spanish I-SAP program. Body weight was estimated indirectly with the Von Bertalanffy equation using live weight, which was also estimated from body depth, stature, and chest width.