1,720,984 research outputs found
Effect of crossbreeding on market value of calves from dairy cows
No full textMarket values (/kg) of calves obtained from six paternal breeds, Brown Swiss (BS), Holstein Friesian (HF), Simmental (SI), Alpine Grey (AG), Limousin (LI) and Belgian Blue (BB), and four maternal breeds (BS, HF, SI, AG), were studied in order to estimate the crossbreeding effects. A total of 58,877 calves sold during 143 weekly auctions from 2003 to 2005 in Bolzano in Italy near the Austrian border, were analyzed using ANOVA procedure according to a linear model that included the effects of cross, sex and age of the calf, year and month of the auction. Coefficient of determination (R-2) was 0.84; cross and sex effects resulted the most important. The BBxSI calves showed the highest commercial value (7.01 /kg), while the BS purebreds the lowest one (2.74 /kg). The LI and BB breeds used as sire breeds showed the greater commercial prices when crossbred with SI and AG respect to BS and HF. However, BB resulted the best sire breed. On average male calves showed greater commercial values than female ones (5.16 vs. 4.44 /kg), but in HF and BS purebreds the commercial value of males and females was similar
Genetic aspects of milk coagulation properties in Italian Holstein cows.
No full textThe aim of this study was to estimate heritability of milk coagulation properties and their genetic correlations
with protein contents for Holstein Friesian cattle breed.
Data. A total of 1071 Italian Friesian cows from 34 herds in Northern
Italy were sampled once during the period from January to July 2004. The milk samples came from the morning
milking and were collected during the milk recording. Samples were analyzed, within maximum 3 hours
from milking time (because they were without any preserving agent), for milk coagulation properties, milk
10 ITAL.J.ANIM.SCI. VOL. 4 (SUPPL. 2), 10-12, 2005
yield, fat and protein percentage, acidity (SH° 50), casein content and somatic cell count (SCC). The milk coagulation
properties (MCP) were determined using a Computerized Renneting Meter (Polo Trade, Italy), allowing
the milk samples to coagulate for a maximum time of 30 minutes, because, in cheese-making process for
most cheese type, curd is usually cut 30 minutes after the addition of the clotting enzyme. The three MCP
determined were milk coagulation time (R) in minutes, curd-firming time (K20) in minutes, and curd firmness
(A30) in millimeters. The R parameter was the time from the addition of rennet to milk to the beginning of
coagulation; K20 was the time from the beginning of coagulation to the moment the width of the curve was 20
mm; A30 was the width of the curve 30 minutes after the addition of rennet. The milk samples that did not
form curd in 30 minutes were defined as non-coagulated (NC) samples. Due to failed coagulation process, 107
samples were excluded so, finally, 964 samples were available for statistical analysis. Pedigree information was
provided by the Italian Holstein-Friesian Breeders Association (ANAFI, Cremona, Italy).
In conclusion, data from this study showed that heritability for MCP were moderate, suggesting that selection
for improving milk rennet-coagulation ability might be effective. Further researches to estimate genetic
parameters between MCP, production traits, casein content and milk protein polymorphism should be considered,
especially to evaluate the opportunity to integrate milk recording system with additional traits related
to milk rennet-coagulation ability, in order to create a possible selection index for cheese production in Italian
Holstein Friesian breed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Relations between different objective milking speed recording systems
No full textThis study aimed to analyse the sources of variation of milking speed assessed through automatic computerised
devices included in milking machines, to study the relationships between this trait and milking
speed assessed through stopwatch and to develop statistical procedures useful for converting automatic
device milking time into stopwatch milking time in order to obtain a fast, simple and cheap collection of
milking time records for genetic evaluation purposes.
A total of 571 records of stopwatch milking time (SMT), device milking time (DMT) and milk yield at milking
were collected in 23 herds of the Trentino Alto Adige region in Italy equipped with two types of automatic
milking devices. After log-transformation of SMT (lnSMT) and DMT (lnDMT) and a preliminary analysis
of sources of variation of lnDMT, dataset was partitioned into two mutually exclusive subsets: a calibration
one, used for statistical analysis, and a validation one, used as test set to validate the prediction
models. This procedure was replicated 6 times in order to repeat the cross validation accordingly. Three
conversion models have been compared, based on different combinations of the effects of lnDMT, milking
device and herd within milking device on lnSMT. Solutions of the models have been applied for each
replicate to the validation dataset for estimating lnSMT and the soundness of conversion equations have
been evaluated considering the correlation between estimated and actual lnSMT and bias and precision
of estimates. Milking time assessed through different procedures resulted in differences between methods
for both mean and distribution, and these suggested the need of developing statistical procedures
aimed to the conversion of DMT into SMT before their use in sire evaulation. The soundness of the models
tended to slightly increase with the increase in the number of effects considered. The correlation
between estimated and actual SMT was in the range of 0.80 to 0.86, the estimated bias was close to 0
for all models and the precision, i.e. the average standard deviation of the difference between estimated
and actual SMT, in the range of 8-9% of the mean of actual SMT. In conclusion, conversion equations proposed
for joining the two sources of information performed satisfactorily, giving rise to SMT accurate estimates,
which were not distorted and fairly precise. The use of such equations can support the integration
of automatically acquired milking time records into breeding schemes, which is advisable for increasing
the number of sires progeny tested and the accuracy of breeding values estimated
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