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Evaluation of fecal sampling time points to estimate apparent nutrient digestibility in lactating Holstein dairy cows
Full text linkINTRODUCTION: The aim of this study was the evaluation of nutrient excretion patterns in samples of feces collected every 2 h to define the best sampling protocol for estimation of apparent digestibility. METHODS: Four multiparous mid-lactation Holstein cows, housed in a tie stall barn and milked twice a day (0800; 1900 h), were enrolled. Dry total mixed ration (TMR) without silages was fed once (0800 h) per day. Feces were sampled every 2 h for 72 h. Each sample was divided in 3 portions: hourly sample sample (8, 10, 12, 14, 16, 18, 20, 22, 00, 2, 4, 6), 8-h composite sample (00–06, 08–14 and 16–22), and a 24-h composite sample. Complete chemical analyses were performed and total tract nutrient digestibility was calculated using undegraded neutral detergent fiber at 240 h of in vitro fermentation (uNDF240h) as a marker. Feeding and rumination patterns were also recorded during the trial. RESULTS AND DISCUSSION: For some parameters, excretion was not constant throughout the day: neutral detergent fiber (aNDFom), undegraded neutral detergent fiber at 24 h of in vitro fermentation (uNDF24h), uDNF240h, total tract crude protein digestibility (TTCPD), total tract neutral detergent fiber digestibility (TTaNDFomD), total tract potentially degraded neutral detergent fiber at 240 h of in vitro fermentation digestibility (TTpdNDF240hD) with minimal values after new TMR delivery and maximal values 12 h after feed delivery. Feeding and ruminating behavior seemed to have an important role in the excretion pattern, due to the pushing and evacuating effect they have. Considering our results, two fecal samples at 12 and 24 h after the TMR delivery are suggested. For one daily sample, 12 h post time of most stable and constant rumination 0000–0600 h, which is also 8 h post feed delivery is suggested
Effects of a completely pelleted diet on growing performance of Holstein heifers.
Full text linkForage neutral detergent fiber (NDF) content and
particle size are important factors that affect rumen
function. The aim of the current study was to evaluate
the effects on rumen health, NDF digestibility, and animal
performance of pelleting a forage-based diet. Eight
Holstein heifers (age 336 ± 30 d, body weight 346 ±
35 kg) were randomly assigned to a repeated crossover
design. Animals were housed in tie-stalls and fed for ad
libitum intake. The study included 4 periods of 3 wk,
the first 2 wk for adaptation to the diet and the last
wk for data collection. Diets had the same ingredients
but had a different physical form: total mixed ration
(TMR) and pellet (diameter = 8 mm). The physically
effective NDF (peNDF) differed between the 2 treatments
(39.8 and 11.8% of NDF in the TMR and pellet
diets, respectively). During the trial, dry matter intake
(DMI), water intake, rumination time, rumen temperature,
and pH were evaluated daily. Fecal samples were
collected in wk 3 of each period to determine total-tract
digestibility of the potential digestible (pd)NDF. Average
daily gain and feed conversion ratio were calculated
at the end of each period. With the pellet diet, DMI,
DMI/body weight, and water consumption were higher.
We observed no significant difference in average daily
gain or feed conversion ratio. Rumination time was
lower for the pellet diet than for the TMR diet (241 vs.
507 min/d, respectively). Diet had no effect on rumen
temperature or rumen pH. The total-tract digestibility
of the pdNDF was greater with the TMR diet than
with the pellet diet (90.25 vs. 86.82% pdNDF, respectively).
The results of the current study suggest that
a complete-feed pellet diet was well accepted by the
animals, as demonstrated by higher DMI. Rumination
time was reduced with the pellet diet, but rumen pH
was not different. The pdNDF digestibility was high for
both diets, but significantly higher for the TMR diet.
Given that animal performance was similar between
the 2 diets, although they differed with respect to DMI
and fiber digestion, we hypothesize that the 2 diets
had different retention times, related to their physical
form. A complete-feed pellet diet formulated to provide
a sufficient level of NDF from forages could be fed to
growing ruminants without apparent negative effects
on rumen health and animal productivity, at least for
a short period. More research over a longer growing
period is needed before recommending this feeding
strategy for growing heife
Effect of feeding whole soybean and linseed on milk and Parmigiano Reggiano cheese lipid fraction
No full textAim of this study was to assess the effects of feeding whole soybean flakes and whole extruded
linseed to dairy cows on milk lipid fraction and Parmigiano Reggiano cheese produced from it; specifically,
PUFA and CLA contents were evaluated. For 14 weeks, a herd of 145 cows received a diet with a daily supplementation
of 1 kg of whole soybean flakes and 0.3 kg of whole extruded linseed. In the pre-trial period,
cows received an isoproteic ration devoid of both seeds. From 20 cows selected from the herd, individual milk,
bulk morning milk and vat milk samples of the entire herd were taken every 14 days. After 24 months of aging,
cheese samples were taken from twelve cheese wheels, obtained from milk produced at 0, 4, 8, 10, 12 and
14 weeks on the same days as bulk milk and vat milk samples were made. Fatty acid composition of the lipid
fraction was determined in all milk and cheese samples. Feeding whole extruded linseed and soybean flakes
has determined a decrease in short-chain fatty acids content and an increase in total CLA concentration of
the milk. Bulk milk, vat milk and aged cheese analysis samples confirmed a decrease of short-chain fatty acids
content in milk and revealed a decrease in n-6/n-3 fatty acid and in saturated/unsaturated fatty acid ratios. In
conclusion, feeding a ration including whole soybean flakes and extruded linseed can improve the nutritional
characteristics of milk and of Parmigiano Reggiano cheese, particularly with respect to their lipid fractions
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
Grains colonised by moulds: fungal identification and headspace analysis of produced volatile metabolites
Full text linkThe aim of this work was to verify if the headspace analysis of fungal volatile compounds produced by some species of Fusarium can be used as a marker of mould presence on maize. Eight samples of maize (four yellow maize from North Italy and four white maize from Hungary), naturally contaminated by Fusarium and positive for the presence of fumonisins, were analyzed to detect moisture content, Aw, volatile metabolites and an enumeration of viable moulds was performed by means of a colony count technique. Headspace samples were analysed using a gas-chromatograph equipped with a capillary column TR-WAX to detect volatile metabolites of moulds. Furthermore macro and microscopic examination of the colonies was performed in order to distinguish, according to their morphology, the genera of the prevalent present moulds. Prevalent mould of eight samples was Fusarium, but other fungi, like Aspergillus, Penicillum and Mucoraceae, were observed. The metabolites produced by F.graminearum and F. moniliforme were Isobutyl-acetate, 3-Methyl-1-butanol and, only at 8 days, 3-Octanone. The incubation time can affect off flavour production in consequence of the presence of other moulds. Further studies on maize samples under different conditions are needed in order to establish the presence of moulds using the count technique and through the identification of volatile compounds
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
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