Estimating soil degradation in montane grasslands of North-eastern Italian Alps (Italy)

Grasslands cover a large portion of the terrestrial ecosystems, and are vital for biodiversity conservation, environmental protection and livestock husbandry. However, grasslands are degraded due to unreasonable management worldwide, i.e., soil erosion indirectly due to the damage of overgrazing on vegetation coverage and soil texture. An in-depth investigation is necessary to quantify soil erosion in alpine pastures, in order to manage grasslands more sustainably. In this work, we collected freely available satellite images and carried out intensive field surveys for the whole Autonomous Province of Trento (Northeastern Italian Alps) in 2016. The area (and volume) of soil erosions were then estimated and shown in maps. The average of the depths of soil erosion measured in field was used as a reference for estimating soil erosion of the entire study area. High-resolution DEMs difference in soil surface conditions was also computed in two representative areas between pre- and post-degradation to estimate the volume and the average depth of eroded soils. The degradation of soil in the study areas has been estimated in 144063 m2 and an estimated volume of 33610 ± 1800 m3. Results indicate that our procedure can serve as a low-cost approach for a rapid estimation of soil erosion in mountain areas. Mapping soil erosion can improve the sustainability of grazing management system and reduce the risk of pastureland degradation at large spatial scales

Factors affecting daughters distribution among progeny testing Holstein bulls

The aim of this study was to investigate factors influencing the number of daughters of Holstein bulls during the progeny testing using data provided by the Italian Holstein Friesian Cattle Breeders Association. The hypothesis is that there are no differences among artificial insemination studs (AIS) on the daughters distribution among progeny testing bulls. For each bull and beginning from 21 months of age, the distribution of daughters over the progeny testing period was calculated. Data were available on 1973 bulls born between 1986 and 2004, progeny tested in Italy and with at least 4 paternal half-sibs. On average, bulls exited the genetic centre at 11.3±1.1 months and reached their first official genetic proof at 58.0±3.1 months of age. An analysis of variance was performed on the cumulative frequency of daughters at 24, 36, 48, and 60 months. The generalized linear model included the fixed effects of year of birth of the bull (18 levels), artificial insemination stud (4 levels) and sire of bull (137 levels). All effects significantly affected the variability of studied traits. Artificial insemination stud was the most important source of variation, followed by year of birth and sire of bull. Significant differences among AI studs exist, probably reflecting different strategies adopted during progeny testing

Short communication: Genetic aspects of milk differential somatic cell count in Holstein cows: A preliminary analysis

The aim of the present study was to assess genetic variation and heritability of a novel indicator of udder health, milk differential somatic cell count (DSCC), which represents the percentage of neutrophils plus lymphocytes in the total somatic cell count (SCC). Furthermore, we estimated genetic and phenotypic correlations of DSCC with other milk traits routinely measured in Italian Holstein cows. Besides DSCC, test-day data included milk yield, composition traits (i.e., fat, protein, casein, and lactose percentages), pH, milk urea nitrogen, and SCC. After editing, the final data set included 10,709 test-day records of 5,142 cows in 299 herds. Mean of DSCC was 62.07%, which means that macrophages were approximately 38% of total SCC. Comparing our results with the literature offered compelling evidence of the importance of acquiring information about the proportion of the different cell types in milk to better define the udder health status. In addition, our analysis revealed, for the first time, that DSCC is a heritable trait, and heritability (0.08 ± 0.02) was higher than that of traditional somatic cell score (0.04 ± 0.02). Nevertheless, heritability of DSCC is still low compared with milk yield and quality traits. Single-trait analysis within parity showed that DSCC was less heritable in primiparous than in multiparous cows, whereas bivariate analysis confirmed that DSCC and somatic cell score were 2 different traits, as their genetic and phenotypic correlations differed from unity. From a genetic point of view, the DSCC was positively weakly associated with milk yield, lactose percentage, and milk urea nitrogen, and negatively associated with pH. Our findings contributed to the understanding of the genetic background of DSCC and are a precursor to the potential use of DSCC in breeding programs to enhance cow resistance to mastitis. However, further research is needed to determine the weight this novel trait should receive in a selection program aimed to reduce udder health problems

Short communication: Effects of pregnancy on milk yield, composition traits, and coagulation properties of Holstein cows.

The aim of this study was to investigate the effect of pregnancy stage on milk yield, composition traits, and milk coagulation properties in Italian Holstein cattle. The data set included 25,729 records from 3,995 first-parity cows calving between August 2010 and August 2013 in 167 herds. The traits analyzed were milk yield (kg/d), fat (%), protein (%), casein (%), and lactose (%) contents, pH, somatic cell score, rennet coagulation time (min), and curd firmness (mm). To better understand the effect of gestation on the aforementioned traits, each record was assigned to one of the following classes of pregnancy stage: (1) nonpregnant, (2) pregnant from 1 to 120d, (3) pregnant from 121 to 210d, and (4) pregnant from 211 to 310d. Gestation stage significantly influenced all studied traits with the exception of somatic cell score. Milk production decreased and milk quality improved from the fourth month of pregnancy onward. For all traits, nonpregnant cows performed very similarly to cows in the first period of gestation. Rennet coagulation time and curd firmness were influenced by pregnancy stage, especially in the last weeks of gestation when milk had better coagulation characteristics; this information should be accounted for to adjust test-day records in genetic evaluation of milk coagulation properties

Comparison between automatic and conventional milking systems for milk coagulation properties and fatty acid composition in commercial dairy herds

AbstractThe aim of this study was to investigate the effect of milking dairy cows using conventional milking parlour (CMP) and automatic milking system (AMS) on milk coagulation properties and fatty acid (FA) composition. Milk coagulation traits were rennet coagulation time, curd-firming time and curd firmness. Data consisted of 10,476 individual milk samples collected from 918 Holstein–Friesian cows in 8 herds: four herds milked cows using a CMP and four using an AMS. A linear mixed model was used to investigate sources of variation for milk yield, traditional quality traits, coagulation properties and FA profile. On average, cows from AMS produced 1 kg/d more milk than cows from CMP. Rennet coagulation time was slightly longer (+1.2 min) and free FA content was greater (+0.16 mmol/100 g milk fat) in milk from cows milked in AMS than CMP. Overall, the milking system did not affect the FA concentration of milk. Results of the present study suggest that AMS can be adopted without detrimental effects on mil..

Short communication: Genetic aspects of milk urea nitrogen and new indicators of nitrogen efficiency in dairy cows.

Milk urea nitrogen (MUN), a trait routinely measured in the national milk recording system, is a useful indicator of nitrogen utilization efficiency of dairy cows, and selection for MUN and MUN-derived traits could be a valid strategy to produce better animals with regard to efficiency of nitrogen utilization. Therefore, the aim of the present study was to explore the genetic aspects of MUN and new potential indicators of nitrogen efficiency, namely ratios of protein to MUN, casein to MUN, and whey protein to MUN, in the Italian Brown Swiss population. A total of 153,175 test-day records of 10,827 cows in 500 herds were used for genetic analysis. Variance components and heritability of the investigated traits were estimated using single-trait repeatability animal models, whereas genetic and phenotypic correlations between the traits were estimated through bivariate repeatability animal models, including fixed effects of herd-test-date, stage of lactation, parity, calving year, and calving season, and the random effects of additive genetic animal, cow permanent environment, and the residual. Heritability estimates for MUN (0.20 ± 0.01) and the 3 new indicators of nitrogen utilization efficiency (0.15 ± 0.01 for protein-to-MUN and casein-to-MUN ratios, and 0.12 ± 0.01 for ratio of whey protein to MUN) suggested that additive genetic variation exists for these traits, and thus there is potential to select for greater organic nitrogen and lower inorganic nitrogen in milk. Genetic association between MUN and the 3 ratios was high (-0.87 ± 0.01) but not unity, suggesting that ratios could provide some further information beyond that provided by MUN with regard to efficiency of nitrogen utilization. Genetic trend of the investigated traits by year of birth of Brown Swiss sires showed how the selection applied in the last 30 yr has led to an increase of both quantity and quality of milk, and a decrease of somatic cell score and MUN. The inclusion of MUN in breeding programs could speed up the process of increasing organic nitrogen such as protein, which is useful for cheese-making, and reducing inorganic nitrogen (MUN) in milk

Cluster Analysis on Across Country Genetic Correlations for Conformation Traits in Holstein Cattle Breed

The aim of this paper is to investigate across country genetic correlations of conformation traits of 21 Holstein bull populations, using cluster analysis. Data consisted of across country genetic correlations of 18 conformation traits estimated by Interbull for the April 2011 routine genetic evaluation. For cluster analysis, the distance measure (dij) between countries i and j was calculated as dij=1-rG2ij, where rGij is the genetic correlation between countries i and j. Traits showed different mean distances with the lowest value for udder depth (0.062) and the highest for locomotion (0.441). For traits with similar definition further investigation is needed to understand differences within cluster. Also, more attention needs to be paid to countries that define or record traits differently from what is suggested by World Holstein Friesian Federation

Milk Yield Traits, Somatic Cell Score, Milking Time and Age at Calving of Pure Holstein Versus Crossbred Cow

Pure Holstein (HO, n=430), crosses between Swedish Red and HO (SRxHO, n=41), Montbeliarde and HO (MOxHO, n=18), and MO and SRxHO (MOxSH, n=53) were compared for milk, fat and protein yield, fat and protein percentage, somatic cell count (SCC), milking time (MT), and age at first and second calving. A total of 180,933 test-day information for milk yield and MT, and 5,249 for fat and protein percentage and SCC were recorded on first and second parity cows milked in one herd of Cremona province (northern Italy). Somatic cell count and MT were log-transformed to somatic cells score (SCS) and LnMT, respectively, before statistical investigation. Production traits, LnMT and SCS were analyzed through a mixed model that included fixed effects of test-day, parity, days in milk (DIM), genotype and interaction between parity and genotype, and the random effects of cow nested within genotype and residual, whereas the model for age at calving included year and month of calving and genotype as fixed effects, and residual as random. MOxHO and pure HO cows differed only for age at second calving (70 d higher for purebreds; P<0.05). Holsteins produced more milk (+2.86 kg/d; P<0.01) and protein yield (+0.05 kg/d; P<0.05) than SRxHO crossbreds, but lower protein percentage (-0.09%; P<0.01), and age at second calving was 44 d (P<0.01) higher than SRxHO. Also, HO produced more milk and fat than MOxSH cows (+1.61 and +0.08 kg/d, respectively; P<0.05), but lower protein percentage (-0.11%; P<0.001), and calved later, both at first and second calving (+24 and +43 d, respectively; P<0.05). Results indicated that crossbred cows can compete with the cosmopolitan breed for several traits

Direct and indirect genetic indices for milk coagulation properties in Italian Holstein Friesian sires

Aim of this study was to define direct and indirect indices for milk coagulation properties (MCP) in Italian Holstein Friesian sires. A total of 315,700 individual milk samples from 49,183 cows were collected in 479 dairy farms from September 2011 to February 2014. Rennet coagulation time (RCT) and curd firmness (a30) were predicted using mid-infrared spectroscopy. Sire breeding values (EBV) for RCT and a30 were estimated using a repeatability single-trait animal model, which included herd-test-day, days in milk, age at parities and season of parity as fixed effects, and cow permanent environment and animal as random effects. The direct genetic index for milk coagulation ability (IAC) was defined as the combination of EBV for RCT and a30 with equal weight, and then expressed on a scale with mean 100 and standard deviation of 5. A stepwise method was chosen to combine official EBVs for traits published by the Italian Holstein Friesian Cattle Breeders Association in a genetic index able to predict the direct IAC. Only sires with at least 10 daughters (scored for MCP) in 5 different herds were considered. The official EBVs retained by the regression analysis were those of protein and fat content, somatic cell score and the genetic variants for k-casein. Results of direct and indirect selection for MCP are presented.Aim of this study was to define direct and indirect indices for milk coagulation properties (MCP) in Italian Holstein Friesian sires. A total of 315,700 individual milk samples from 49,183 cows were collected in 479 dairy farms from September 2011 to February 2014. Rennet coagulation time (RCT) and curd firmness (a30) were predicted using mid-infrared spectroscopy. Sire breeding values (EBV) for RCT and a30 were estimated using a repeatability single-trait animal model, which included herd-test-day, days in milk, age at parities and season of parity as fixed effects, and cow permanent environment and animal as random effects. The direct genetic index for milk coagulation ability (IAC) was defined as the combination of EBV for RCT and a30 with equal weight, and then expressed on a scale with mean 100 and standard deviation of 5. A stepwise method was chosen to combine official EBVs for traits published by the Italian Holstein Friesian Cattle Breeders Association in a genetic index able to predict the direct IAC. Only sires with at least 10 daughters (scored for MCP) in 5 different herds were considered. The official EBVs retained by the regression analysis were those of protein and fat content, somatic cell score and the genetic variants for k-casein. Results of direct and indirect selection for MCP are presented