Assessment of the heritability coefficients of longevity traits in the population of Black and White cows was performed on a data set that included production results of 16,539 of black and white culled cows, which reached a total of 50,382 lactations in the period from 1985 to 2012. The cows were grown on 7 farms of the Agricultural Corporation Belgrade and are progeny of 277 bulls. The analysis covered the following traits: length of productive life (LPL), lifetime milk yield (LMY) and number of lactations (NL). Variance components of longevity traits were estimated using a BLUP linear mixed model with animal as a random effect. Cows included in the analysis calved for the first time in the average age of 26.86 months, while the average length of productive life amounted to 1,299.9 days and during that time the animals achieved an average of 3.04 lactations and life time production of 21,016 kg of milk. The values of the heritability coefficients of longevity traits ranged from 0.066; 0.061 and 0.074 regarding the length of productive life, lifetime milk yield and number of lactations respectively.

This study analyzes the micromorphological and mineralogical properties of a Terra Rossa soil under a traditional Mediterranean olive grove. It highlights the microscopic and sub-microscopic features generated by the permanent crop cover. The study area, where the land use has remained unchanged for the last 150 years, is near Sassari (Sardinia, Italy) and is characterized by dominant Terra Rossa developed on Miocene marine limestone. Two soil profiles were opened and described in July 2009, 1 under the canopy of an olive tree and 1 between the trees. Chemical and physical analyses were carried out. Undisturbed aggregates were collected from all the sampled horizons for thin section and scanning electron microscope (SEM) analysis, complemented by mineralogical analyses (X-ray diffractometry, XRD). The results obtained highlighted the effects of vigorous bioturbation and stress actions that have occurred on the pedogenetic features inherited from complex genetic processes.

No abstract

In this study, the authors focused on the evaluation of the genetic parameters of longevity, milk yield traits, and type traits in dairy cattle populations in the Republic of Serbia. The total dataset used consisted of production records and pedigree data for 32,512 Holstein cows that calved from 1981 to 2015. The animal model was applied to determine the variance and covariance components and genetic parameters of the analyzed traits by applying the restricted maximum likelihood (REML) approach and using the programs VCE6 and PEST. The heritability of longevity traits was estimated using the Survival Kit V6.0 software package. Variance and covariance were estimated for five production traits: milk yield (MY), fat yield (FY), protein yield (PY), milk fat content (MC), and protein content (PC), and three longevity traits: length of productive life (LPL), lifetime milk yield (LMY), and the number of lactations achieved (NL) as well as for 18 standard type traits. Heritabilities for the milk, fat, and protein yield traits were 0.20 (MY), 0.15 (FY), and 0.19 (PY), respectively. The estimated coefficients of heritability for the longevity traits were higher when using the Weibull proportional hazards model compared to the traditional linear methods and ranged from 0.08 for NL to 0.10 for LPL. Heritability values for the type traits varied from a low of 0.10 (RLSsv—rear legs set–side view) to medium values of 0.32 (ST-stature). Genetic correlations were found between MY and the following longevity traits: LPL, LMY, and NL with values of −0.18, −0.11, and −0.09, respectively. Genetic correlations were found between MY and a number of linear type traits and varied from 0.02 (between MY and RUH-rear udder height) to 0.28 (between MY and FUA-fore udder attachment). Genetic correlations between the 18 investigated type traits ranged from −0.33 between TL (top line) and RTP (rear teats position) to 0.71 between AN (angularity) and RUH (rear udder height). Genetic correlations between most linear type traits and longevity traits (LPL, LMY, and NL) were generally negative and very low. The highest positive genetic correlation was found between UD and LPL (rxy = 0.38).

No abstract