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Effect of the lactation stage and body condition score on the fatty acid profile of milk fat
Get PDFKäesolev magistritöö on osa institutsionaalsest uurimisprojektist (IUT8-1) ,,Piimalehmade
sigimine ja tervis“.
Magistritöö ülesanneteks oli anda kirjanduse põhjal ülevaade piimarasvas leiduvatest
rasvhapetest ja nende päritolust ning selgitada laktatsioonijärgu ja lehmade poegimiseelse
toitumishinde mõju piimarasva rasvhappelisele profiilile. Katse käigus koguti piimaproovid
Eerika Farm OÜ laudas viieteistkümnelt katselehmalt alates seitsmendast poegimisjärgsest
lüpsist kuni laktatsiooni lõpuni. Toitumushinde alusel jaotati lehmad kolme rühma: esimesel
rühmal oli toitumushinne ≤3,0 palli, teisel 3,25-3,5 palli ning kolmandal rühmal ≥3,75 palli.
Piimaproovidest määrati piimarasva rasvhappeline koostis ning rasvhapete osakaalud Eesti
Maaülikooli piima kvaliteedi uurimise laboris.
Uurimustöö käigus leiti, et laktatsiooniperiood mõjutas oluliselt enamiku rasvhapete osakaalu
piimarasva rasvhapetes ning suurimad muutused piimarasva rasvhappelises profiilis toimusid
laktatsiooni 1.-12. nädalani. De novo sünteesitud rasvhapete osakaal piimarasvas suurenes
kuni 12. laktatsiooninädalani ning seejärel stabiliseerus. Ka enamiku vatsamikroobidest
pärinevate hargnenud ja paarituarvulise süsinikahelaga rasvhapete osakaalud piimarasva
rasvhapetes suurenesid laktatsiooni jooksul, seejuures olid muutused suuremad laktatsiooni
alguses. Rasvkoest pärinevate rasvhapete osakaal oli laktatsiooniperioodi alguses suurem kui
oli laktatsiooni edenedes.
Lehmade poegimiseelne toitumushinne mõjutas oluliselt piimarasva rasvhappelist profiili - de
novo sünteesitud rasvhapete osakaal oli laktatsiooni kümnendal nädalal väikseim (23,0 g/100
g rasvhapetes) suurima poegimiseelse toitumushindega (BCS3,75) lehmade piimarasva
rasvhapetes. Alates laktatsiooni kümnendast nädalast oli monoküllastamata rasvhapete
osakaal suurim (32,0-25,5 g/100 g rasvhapetes) suurima poegimiseelse toitumushindega
(BCS3,75) lehmade piimarasva rasvhapetes. Laktatsiooni esimesel nädalal oli hargenud
ahelaga rasvhapete osakaal suurim (1,60 g/100 g rasvhapetes) madalaima toitumushindega
(BCS≤3,0) lehmade piimarasva rasvhapetes.The master’s thesis is a part of the institutional research project (IUT8-1) „Fertility and health
of dairy cattle“.
The objective of the thesis was to give an overview of the literature on milk fat fatty acids and
their origin and to explain the effect of lactation stage and body condition score (BCS) at
drying off on the milk fatty acid profile. Milk samples for fatty acid analyses were collected
throughout lactation from 15 cows at Eerika Farm OÜ. Cows were divided into three groups
according to their body condition score at drying off: first group BCS ≤3,0, second group
BCS 3,25-3,5 and third group BCS≥3,75. The milk fatty acid profile was analysed using gas
chromatograph in the Laboratory of Milk Quality at the Estonian University of Life Science.
The lactation period affected the proportion of most fatty acids in milk fat and most noticeable
changes took place between the 1
st and 12th week of lactation. The proportion of de novo
synthesized fatty acids increased until the week 12 of the lactation and then stabilized. The
proportions of most odd- and branched-chain fatty acids in milk fat increased during lactation
and the increase was more distinct in early lactation. The proportions of fatty acids originating
from adipose tissue were higher at the beginning of lactation.
The body condition score of the cows at drying off significantly affected the fatty acid profile
of the milk fat. The proportion of the sum of de novo synthesized fatty acids in week 10 of
lactation was the smallest (23,0 g/100 g fatty acids) in cows with the highest body condition
score (BCS3,75) Starting from the 10th week of lactation the proportion of the sum of
monounsaturated fatty acids was the biggest (32,0-25,5 g/100 g fatty acids) in cows with the
highest body condition score (BCS3,75). At the first week of lactation, the proportion of the
sum of odd- and branched-chain fatty acids was the biggest (1,60 g/100 g fatty acid) in cows
with the smallest body condition score (BCS≤3,0)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Factors affecting milk yield in dairy cows
No full textPiima tootmine on Eestis viimase 40 aastaga arenenud kõrgele tasemele – uuenenud on nii
farmides kasutatav tehnika, tehnoloogia ning märkimisväärselt paranenud
piimajõudlusnäitajad.
Piimajõudlust mõjutavad tegurid võib jagada kaheks – pärilikud ja mittepärilikud tegurid.
Neist esimesed mõjutavad piimajõudlust 30% ja teised 70%.
Valides kõrge aretusväärtusega pulle, suurendatakse tütarde piimajõudlusnäitajaid.
Mittepärilikest teguritest mõjutab piimajõudlust kehaehitus, poegimisvahemik, söötmine,
pidamistingimused, lüpsmine ja töövõtted lüpsil, lehma tervis jm. Mitme uurimustöö
analüüsist selgus, et mida suuremad kehamõõtmed ja –mass ning rinna sügavus, seda suurem
on toodang.
Poegimisvahemik võiks olla mitte üle 390 päeva. Uuslüpsiperiood mitte üle kolme kuu. Et
lehm saaks puhata ja anda järgmisel laktatsiooniperioodil võimalikult palju toodangut, oleks
sobiv kinnisperioodi pikkus keskmiselt 60 päeva.
Lehma piimajõudlus kasvab koos vanusega kuni kuuenda laktatsioonini ning pärast seda
hakkab tasapisi langema, kuid kaasaegsetes farmides püsivad lehmad karjas keskmiselt neli
aastat ja seitse kuud. Lehma karjaspüsimist mõjutab tervis, samas suur osa lehmi praagitakse
haiguse tõttu. Tervise tagab lehmade õige söötmine ja head pidamistingimused. Oluline on ka
veisefarmi mikrokliima, kui temperatuur on liiga kõrge, väheneb loomadel söömuse tase ning
ainevahetus aeglustub ja piimatoodang väheneb.
Lüpsitehnika ja töövõtted lüpsil on olulised piima jõudlusnäitajatele ning piima kvaliteedile.
Tänapäeva uutes farmides on kasutusel lüpsirobotid, mis võivad olla üheks teguriks
piimajõudluse suurenemisel, sest selline lüpsiteholoogia ei vaja inimese osalemist
lüpsiprotsessis, vaid inimene jälgib lüpsi arvuti vahendusel.
Toetudes kirjandusallikatele võib järeldada, et veiste piimajõudlus oleneb nii piimalehma
pärilikest kui ka mittepärilikest teguritest.Dairy farming has evolved rapidly over the last 40 years. New technologies have been
introduced while the average milk yields per cow have been steadily increasing. The aim of
this study was to describe the key factors affecting milk production on dairy farms.
Factors affecting milk production can be divided into two categories – genetic and nongenetic
factors. The impact of non-genetic factors is more significant.
Breeding value helps to assess the gene effects of a breeding animal – the daughters of the
bulls of higher genetic merit have potential for higher milk yield.
Non-genetic factors affecting milk production are body measurements, calving interval,
feeding, housing, milking (including the quality and performance of milking staff, cow health
and farm microclimate. Multiple reseach analyses have shown that body weight as well as,
breast size and depth are related to the milk yield of cows. Calving intervals between 320 and
365 days maximize the milk production. Days open should last for about three months and the
average dry period for 60 days, so that a cow has enough time to rest and can produce more
milk.
Milk yield increases with age until about the sixth lactation, after which it slowly starts to
decline. On modern farms, however, a cow remains in the dairy herd until four years and
seven months of age as an average. Health problems are the main reason for culling of dairy
cows. Pproper feeding and adequate housing conditions provide for better herd health and
welfare. Optimal keeping conditions reduce stress and guarantee maximum productivity of
cattle. Microclimatic conditions also affect the milk yield. For instance,e, if the temperature is
too high, feed intake is lower, metabolism slows down and and milk production will decrease.
Milking techniques and technologies affect the composition of milk. The quality and
efficiency of the milking staff is also very important as it may affect the somatic cell count in
milk and udder health
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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