118 research outputs found

    Effects of Îș-CN Glycosylation on Rennet Coagulation Properties of Milk in Simmental Cattle

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    Contents of casein fractions are known to affect coagulation properties and cheese yield of milk, but studies on the effects of Îș-CN composition on variation of coagulation properties of milk are still very scarce. Effects exerted by Îș-CN composition on variation of milk coagulation properties (MCP) were investigated using 2,084 individual milk samples of Simmental cows. Rennet coagulation time (RCT), and curd firmness (A30) were measured using a computerized renneting meter. Milk protein composition and genotypes at CSN2, CSN3 and BLG were obtained by reversed-phase HPLC. The percentage ratios of Îș-CN (ÎșCN%), of Glycosylated-Îș-CN (G-ÎșCN%), and Unglycosylated-Îș-CN (U-ÎșCN%) to total casein were measured. The degree of glycosylation (GD) was measured as the percentage ratio of glycosylated-Îș-CN to total Îș-CN. A difference of 1.7 min (corresponding to 0.37 SD of the trait) was observed for the average RCT of the two extreme classes of ÎșCN% content. RCT decreased when ÎșCN% and G-ÎșCN% increased, whereas U-ÎșCN% exhibited a slightly unfavourable effect on the onset of the coagulation process. A slight decrease of RCT was also observed for high GD, although this effect was less clear than that of G-ÎșCN%. A favourable effect of ÎșCN%, G-ÎșCN% and GD on A30 was also detected

    Analysis of genetic correlations between multivariate measures of lactation persistency and somatic cell score in Italian Simmental cattle

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    Genetic relationships between lactation curve traits and Somatic Cell Count are of great interest for dairy cattle breeding. Factor Analysis (MFA) and Principal Component Analysis (PCA) can be used to extract from the correlation matrix of milk test day records new unobservable (latent) variables that can be related to lactation curve shape. Previous researches report that MFA is particularly able to extract two latent variables related with level of production in early lactation (PEL) and lactation persistency (PERS), respectively, whereas PCA yields a leading component related to the average level of production (AVY) for the whole lactation and a second component negatively related with tests of early lactation and positively with tests of the second part of lactation (SLOPE). Aim of this work was to estimate genetic correlations between lactation curve shape traits and Somatic Cell Score (SCS). MFA and PCA were carried out on a data set of 16,020 lactations of Italian Simmental cows, each with six TD records for milk yield recorded with the A4 scheme. Genetic parameters were estimated with a bivariate animal model that included fixed effects of herd-test date, parity*age*lactation stage (only parity*age for lactation curve traits), calving season, and random effects of additive genetic and permanent environment. Heritability estimates were moderate for lactation curve traits (0.15, 0.15, 0.21 and 0.09 for PEL, PERS, AVY and SLOPE, respectively) and low for SCS (0.09). Correlations between lactation curve traits and SCS were favourable, i.e. negative, except for the level of production in early lactation. In particular, the genetic improvement of lactation persistency result in a contemporary reduction of SCS (rg -0.55 and -0.51 with PERS and SLOPE, respectively) whereas the increase of level of production in early lactation can lead to a moderate increase of SCS (rg 0.13). Finally, the two measures of persistency could be used for different selection strategies: the use of PERS may allow for the increase of persistency together with the total lactation yield whereas the use of SLOPE may result in an improvement of the lactation curve shape without modifying total lactation yield

    Heritabilities and Genetic Correlations of Body Condition Score and Muscularity with Productive Traits and their Trend Functions in Italian Simmental Cattle

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    With the aim to study the genetics of energy and muscle balance in the Italian Simmental breed, the objectives of this study were: i) the estimation of the genetic parameters for body condition score (BCS) and muscularity (MU) score; ii) the estimation of genetic correlations of BCS and MU with productive traits; iii) the estimation of the expected pattern of BCS and MU over lactation. A total of 47,839 records of first-parity lactating cows, collected from 1999 to 2007 in 2794 herds, were used. Two-trait animal models were analyzed using restricted maximum likelihood (REML) procedures to estimate (co)variance components. The expected patterns of BCS and MU along the lactation of first parity cows were estimated from the solutions of DIM fixed effect obtained from an univariate mixed model for both the traits. The heritability estimated was 0.18 for BCS, 0.38 for MU, and ranged from 0.13 to 0.18 for yield traits. The genetic correlations between BCS, MU and yield traits were negative (-0.17 to -0.63). The genetic correlation between BCS and MU was strongly positive (0.88), indicating that cows that genetically tend to have high BCS are more likely to have high values of MU. The genetic parameters estimated suggested that selection for BCS and MU in dual purpose breeds may be possible, and BCS may indirectly improve MU. The expected patterns for BCS and MU showed the trend of these two traits along the lactation and can help farmers in planning the best management of the lactating cows

    Temperature and humidity index (THI) affects salivary cortisol (HC) and dehydroepiandrosterone (DHEA) concentrations in growing bulls following stress generated by performance test procedures

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    The hypothalamus-pituitary–adrenal axis response to a challenge was proposed for genetic selection of robust and resilient animals. As ACTH (adrenocorticotropic hormone) test and hormone measurements in blood may result impractical, it may be useful to measure salivary hormones in response to natural stressors, after an accurate biological validation, to control factors that could contribute to the response. We evaluated whether animal handling during performance test affects salivary HC and DHEA secretion and could be used for selection. We tested the effects of habituation to repeated handling and THI as putative bias. Bull calves (N = 273) undergoing performance test were sampled at 8–9 and 11–13 months (N = 101), 8–9 months (N = 131), or 11–13 months (N = 41). On each test day (D0), calves were isolated, conducted to a squeeze chute and immobilized for 6 min. Saliva samples were collected in the morning after feed administration (T0), and after 6 min immobilization in the squeeze chute (T1) for HC and DHEA measurement. Environmental temperature and relative humidity were recorded every hour from 1:00 h to 24:00 h during the 6 days before the performance test and on D0. Salivary HC and DHEA concentrations were higher in T1 (p < 0.01), although a clear individual positive response to handling could be observed in less than 10% of subjects. The mixed model revealed: (i) HC and HC/DHEA were higher in Young bulls (p < 0.05). (ii) The time of T0 sample collection significantly affected DHEA (p < 0.01) and HC/DHEA (p < 0.05). (iii) THI affected both steroids (p < 0.001) but not HC/DHEA. Spearman correlations suggested that THI weakly affected salivary HC at T0 only (ρ = 0.150, p < 0.01), while moderate statistically significant correlations were found between DHEA and THI at T0 (ρ = 0.316, p < 0.001), and T1 (ρ = 0.353, p < 0.001). Salivary HC and DHEA in response to handling procedures might identify subpopulations of subjects with sensitive HPA axis. Habituation to repeated handling played a role, as the hormone response was lower in older animals. Chronic exposure to high THI had a minor effect on salivary HC visible at T0. A more intense THI effect was observed on salivary DHEA concentrations at both T0 and T1, which should be worth of further investigations

    Bioaccessibility of carotenoids, vitamin A and alpha-tocopherol, from commercial milk-fruit juice beverages: Contribution to the recommended daily intake

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    Twenty-two commercial milk-fruit juice beverages (MFJBs) were analysed by high performance liquid chromatography with diode array detector for carotenoids, retinol and α-tocopherol content. Bioaccessibility was also investigated by in vitro enzymatic digestion. Total carotenoids content and vitamin A calculated as retinol plus pro-vitamin A carotenoids varied widely among samples as well as the bioaccessibility, depending on the formulations. The predominant carotenoid present in all the samples was ÎČ-carotene, followed by α-carotene, ÎČ-cryptoxanthin and zeaxanthin, which were not detected in all the samples. One daily consumption of MFJB (200 mL) provides on average from 5% to 11% of the Recommended Dietary Allowance (RDA) for vitamin A, depending on the age group and a slightly higher value for α-tocopherol. The bioaccessibility of bioactive carotenoids in increasing order was the following: ÎČ-carotene < α-carotene < phytofluene = phytoene < lutein = ÎČ-cryptoxanthin < zeaxanthin. If we consider bioaccessibilities the contribution to the RDA is drastically reduced by 40% for vitamin A and about 13% for vitamin E.ConsejerĂ­a de InnovaciĂłn Ciencia y Empresa, Junta de AndalucĂ­a P11-AGR-7783CYTED 112RT044

    Effects of Îș-CN Glycosylation on Rennet Coagulation Properties of Milk in Simmental Cattle

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    Contents of casein fractions are known to affect coagulation properties and cheese yield of milk, but studies on the effects of Îș-CN composition on variation of coagulation properties of milk are still very scarce. Effects exerted by Îș-CN composition on variation of milk coagulation properties (MCP) were investigated using 2,084 individual milk samples of Simmental cows. Rennet coagulation time (RCT), and curd firmness (A30) were measured using a computerized renneting meter. Milk protein composition and genotypes at CSN2, CSN3 and BLG were obtained by reversed-phase HPLC. The percentage ratios of Îș-CN (ÎșCN%), of Glycosylated-Îș-CN (G-ÎșCN%), and Unglycosylated-Îș-CN (U-ÎșCN%) to total casein were measured. The degree of glycosylation (GD) was measured as the percentage ratio of glycosylated-Îș-CN to total Îș-CN. A difference of 1.7 min (corresponding to 0.37 SD of the trait) was observed for the average RCT of the two extreme classes of ÎșCN% content. RCT decreased when ÎșCN% and G-ÎșCN% increased, whereas U-ÎșCN% exhibited a slightly unfavourable effect on the onset of the coagulation process. A slight decrease of RCT was also observed for high GD, although this effect was less clear than that of G-ÎșCN%. A favourable effect of ÎșCN%, G-ÎșCN% and GD on A30 was also detected

    Commissioning of the SPARC Movable Emittance Meter and Its First Operation at PITZ

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    For the SPARC Project a novel diagnostic device, called "Emittance-meter", has been conceived and constructed to perform a detailed study of the emittance compensation process in the SPARC photo-injector and to optimize the RF-gun and the accelerator working point. It consists of a movable emittance measurement system, based on the 1D pepper-pot method, installed between two long bellows with the possibility to scan a region 1.2 m long downstream the RF-gun. The construction of the device was completed in the first part of this year and a series of laboratory tests, to evaluate its performances, were carried out in Spring 2005. At the beginning of the summer the complete system was moved to DESY at Zeuthen to be installed on the Photo Injector Test Facility PITZ. After the commissioning it will used for measurements of the PITZ electron beam in the framework of a collaboration between the SPARC and PITZ Projects aiming on studies and operations with photo injectors

    Multiphoton photoemission from a copper cathode illuminated by ultrashort laser pulses in an RF photoinjector.

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    In this Letter we report on the use of ultrashort infrared laser pulses to generate a copious amount of electrons by a copper cathode in an rf photoinjector. The charge yield verifies the generalized Fowler-Dubridge theory for multiphoton photoemission. The emission is verified to be prompt using a two pulse autocorrelation technique. The thermal emittance associated with the excess kinetic energy from the emission process is comparable with the one measured using frequency tripled uv laser pulses. In the high field of the rf gun, up to 50 pC of charge can be extracted from the cathode using a 80 fs long, 2\text{ }\text{ }\ensuremath{\mu}\mathrm{J}, 800 nm pulse focused to a 140\text{ }\text{ }\ensuremath{\mu}\mathrm{m} rms spot size. Taking into account the efficiency of harmonic conversion, illuminating a cathode directly with ir laser pulses can be the most efficient way to employ the available laser power

    Fibrosis-4 (FIB-4) Index and mortality in COVID-19 patients admitted to the emergency department

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    Liver damage worsens the prognosis of coronavirus 19 disease (COVID-19). However, the best strategy to stratify mortality risk according to liver damage has not been established. The aim of this study is to test the predictive value of the validated Fibrosis-4 (FIB-4) Index and compared it to liver transaminases and to the AST-to-Platelet ratio index (APRI). Multicenter cohort study including 992 consecutive COVID-19 patients admitted to the Emergency Department. FIB-4 > 3.25 and APRI > 0.7 were used to define liver damage. Multivariable Cox regression and ROC curve analysis for mortality were performed. Secondary endpoints were (1) need for high-flow oxygen and (2) mechanical ventilation. 240 (24.2%) patients had a FIB-4 > 3.25. FIB-4 > 3.25 associated with an increased mortality (n = 119, log-rank test p  3.25 was also superior to APRI > 0.7 (AUC 0.58, 95% CI 0.553-0.615, p = 0.0008). Using an optimized cut-off > 2.76 (AUC 0.689, 95% CI 0.659-0.718, p  3.25 (p = 0.0302), APRI > 0.7 (p  51 (p = 0.0119) and ALT > 42 (p < 0.0001). FIB-4 was also associated with high-flow oxygen use (n = 255, HR 1.69, 95% CI 1.25-2.28, p = 0.001) and mechanical ventilation (n = 39, HR 2.07, 95% CI 1.03-4.19, p = 0.043). FIB-4 score predicts mortality better than liver transaminases and APRI score. FIB-4 score may be an easy tool to identify COVID-19 patients at worse prognosis in the emergency department
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