1,720,954 research outputs found
The role of age at first calving in shaping production and reproductive outcomes in Italian buffaloes
No full textThe age at first calving (AFC) is a critical parameter in dairy herd management due to its impact on feeding costs, genetic progress, longevity, and thus, farm profitability. With the growing global demand for buffalo milk products, recent advancements in reproductive practices and feeding techniques have contributed to a reduction in AFC in Italy. This study investigates the impact of AFC on the productive and reproductive performance of primiparous Italian Mediterranean buffaloes. Data were collected from 50,661 animals across 115 herds, covering 362,703 first-lactation test-day records from 2013 to 2023. The study analyzed productive traits, including milk yield (kg/d), days to milk peak (DMP, d), ECM (kg/d), fat and protein contents (%), and SCS. Reproductive traits, such as calving interval (CIN, d) and days open (DO, d), were analyzed from 2013 to 2021. Repeated mixed linear models were used to assess the effects of AFC on the afore-mentioned traits, accounting for DIM, calving year and season, and, when applicable, their interactions. Results highlighted a significant reduction in AFC (from 36 to 35 mo), CIN (from 457 to 447 d), and DO (from 147 to 136 d) over the studied period. Buffaloes with AFC >42 mo produced 0.52 kg/d more milk and 0.90 kg/d more ECM, with slightly higher fat content (+0.04%) compared with those with AFC ≤32 mo. This trend was consistent throughout DIM categories. Somatic cell score was significantly lower in buffaloes with AFC between 32 and 35 mo (2.78), whereas higher SCS was observed in those with AFC ≤32 mo (2.81) or >35 mo (2.80). Buffaloes with AFC comprised between 34 and 37 mo had significantly lower CIN and DO (449–450 and 137–139 d, respectively) compared with those with both lower or greater AFC (454 and 143 d, respectively), whereas DMP was not significantly affected by AFC. As expected, likely due to the out-of-breeding technique, the highest values for both CIN and DO were observed in buffaloes calving the first time in winter and spring (on average 455 and 145 d, respectively), and lower values were recorded for those calving in autumn and summer (on average 449 and 138 d, respectively). Buffaloes with AFC ≤30 mo that calved during winter exhibited significantly greater DO (>150 d) compared with those calving with AFC >42 mo during the same period (140 d). This is likely due to the lower capacity to restore ovarian activity that may reduce fertility in younger buffaloes compared with older ones. Conversely, buffaloes with AFC >42 mo that calved in summer tended to have extended DO (139 d) in respect to those with lower AFC (≤30 mo) in the same period (135 d). This may be due to the interaction between the increased photoperiod and the reduced feed intake caused by summer heat stress, which may have an effect on older buffaloes' fertility. Therefore, AFC between 34 and 37 mo represents the optimal window for Italian Mediterranean buffaloes, combining shorter CIN and DO with sustained milk production. The reduction of AFC could significantly enhance farm profitability and may be achievable through the integration of breeding programs, better reproductive technologies across seasons, and targeted nutritional strategies during the preweaning and prepartum phases
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
The role of age at first calving in shaping production and reproductive outcomes in Italian buffaloes
No full textThe age at first calving (AFC) is a critical parameter in dairy herd management due to its impact on feeding costs, genetic progress, longevity, and thus, farm profitability. With the growing global demand for buffalo milk products, recent advancements in reproductive practices and feeding techniques have contributed to a reduction in AFC in Italy. This study investigates the impact of AFC on the productive and reproductive performance of primiparous Italian Mediterranean buffaloes. Data were collected from 50,661 animals across 115 herds, covering 362,703 first-lactation test-day records from 2013 to 2023. The study analyzed productive traits, including milk yield (kg/d), days to milk peak (DMP, d), ECM (kg/d), fat and protein contents (%), and SCS. Reproductive traits, such as calving interval (CIN, d) and days open (DO, d), were analyzed from 2013 to 2021. Repeated mixed linear models were used to assess the effects of AFC on the afore-mentioned traits, accounting for DIM, calving year and season, and, when applicable, their interactions. Results highlighted a significant reduction in AFC (from 36 to 35 mo), CIN (from 457 to 447 d), and DO (from 147 to 136 d) over the studied period. Buffaloes with AFC >42 mo produced 0.52 kg/d more milk and 0.90 kg/d more ECM, with slightly higher fat content (+0.04%) compared with those with AFC ≤32 mo. This trend was consistent throughout DIM categories. Somatic cell score was significantly lower in buffaloes with AFC between 32 and 35 mo (2.78), whereas higher SCS was observed in those with AFC ≤32 mo (2.81) or >35 mo (2.80). Buffaloes with AFC comprised between 34 and 37 mo had significantly lower CIN and DO (449-450 and 137-139 d, respectively) compared with those with both lower or greater AFC (454 and 143 d, respectively), whereas DMP was not significantly affected by AFC. As expected, likely due to the out-of-breeding technique, the highest values for both CIN and DO were observed in buffaloes calving the first time in winter and spring (on average 455 and 145 d, respectively), and lower values were recorded for those calving in autumn and summer (on average 449 and 138 d, respectively). Buffaloes with AFC ≤30 mo that calved during winter exhibited significantly greater DO (>150 d) compared with those calving with AFC >42 mo during the same period (140 d). This is likely due to the lower capacity to restore ovarian activity that may reduce fertility in younger buffaloes compared with older ones. Conversely, buffaloes with AFC >42 mo that calved in summer tended to have extended DO (139 d) in respect to those with lower AFC (≤30 mo) in the same period (135 d). This may be due to the interaction between the increased photoperiod and the reduced feed intake caused by summer heat stress, which may have an effect on older buffaloes' fertility. Therefore, AFC between 34 and 37 mo represents the optimal window for Italian Mediterranean buffaloes, combining shorter CIN and DO with sustained milk production. The reduction of AFC could significantly enhance farm profitability and may be achievable through the integration of breeding programs, better reproductive technologies across seasons, and targeted nutritional strategies during the preweaning and prepartum phases
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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