244 research outputs found
Possibilities and requirements for organic dairy breeding lines
The potential of breeding lines that are genetically adapted to organic milk production is essentially unexploited even though specific lines offer the potential to breed for cows with characteristics specific for organic production systems
Koens gener kan afgøre mælkens sundhed
Stamtræet har i høj grad betydning for, hvilke kvaliteter koens mælk har, viser forskning fra Aarhus Universitet og SEGES. Det giver nye muligheder for at producere mælk med specifikke egenskaber
SOBcows posterpræsentation til statusmøde
Overblik over projektets baggrund, aktiviteter og resultate
COMPARISON OF GROWTH PERFORMANCE OF BEEF CALVES FROM DIFFERENT GENETIC STRAINS REARED UNDER ORGANIC CONDITIONs (D. 3.2)
The objective of the present study was to compare growth performance of 15 Danish Holstein bull (DHB) calves, 15 Limousine x Danish Holstein crossbred bull (CB) calves and 15 Limousine x Danish Holstein crossbred heifer (CH) calves reared under organic conditions. Spring-born calves were puchased at private farms and arrived at approximately 20 days of age with an average initial body weight of 52.9, 58.5 and 56.1 kg, (SEM 2.6) for DHB, CB and CH, respectively. Calves were kept indoor until weaning at 3 months of age. Calves were gradually introduced to a grass-silage based ration from 3 to 4 months of age. From 4 to 7 months calves were kept on mix grass pasture of ryegrass and white clover. There were significant differences between treatment groups in terms of average daily gain (ADGP1) during the first summer pasture period, average daily gain (ADGI) during the indoor winter period, and average daily gain (ADGP2) during the second summer pasture period (first 7 weeks). Thus, CB had significantly greater ADG than CH for all three periods with DHB being in between. CB had greater values than DHB and CH in terms of LWP1 144, 140 and 135 (SEM 4) kg, ADGP1 1.15, 1.04 and 0.95 (SEM 0.05) kg/d, LW Indoor 222, 213, and 201 (SEM 5) kg and ADGI 1.06, 1.02 and 0.95 (SEM 0.02) kg/d, LWP2 462, 445 and 414 (SEM 9) kg and ADGP2 1.24, 0.98 and 0.68 (SEM 0.04) kg/d for CB, DHB and CH, respectively. The final live weight were not different between CB and DHB but was significantly lower for CH than DHB and CB (483, 539 and 582 (SEM 8) kg, for CH, DHB and CB, respectively). Overall growth performance across all periods was 13% higher for CB than CH
Fedtsyreregistrering i Danmark
Det er første gang i historien, der findes fedtsyreregistreringer på alle køer i et land. Informationer om fedtsyreindholdet i mælken er indsamlet fra samtlige ydelseskontrollerede køer i Danmark
Økologer lægger vægt på høj mælkeydelse som avlsmål
En spørgeskemaundersøgelse foretaget i forskningsprojektet SOBcows viser, økologiske mælkeproducenter lægger større vægt på at højere mælkeydelse gennem avlsarbejdet, end forskerne havde forventet
Fedtsyreprofilen i mælk fra malkekøer - potentiale og perspektiver
Projektet SOBcows har i samarbejde med RYK gennem 16 måneder i 2015/16 analyseret for indholdet af fedtsyrer i kontrolmælken fra alle ydelseskontrollerede køer i Danmark. Rapporten præsenterer opgørelser på målingerne og evaluerer potentialet i at bruge viden om mælkens fedtsyreprofil i avl og produktion samt i forhold til fedtsyrernes betydning for human sundhed.
En litteraturgennemgang viser, at fedtsyresammensætningen i komælk varierer betydeligt og er påvirket af en række faktorer relateret til fodring, race og management. Fodring med græs- eller urtebaserede rationer øger mælkens indhold af umættede C18-fedtsyrer, og tilsvarende øger fodring med mættet fedt indholdet af palmitin– og stearinsyre (C16:0 og C18:0) i mælkefedtet. Litteraturen viser desuden en stor forskel i mæl-kens fedtsyreprofil både mellem køer indenfor racer og mellem racer. Til brug i produktionsovervågning kan ændringer i mælkens fedtsyreprofil afspejle store vægttab i starten af laktationen, mens et forhøjet indhold af fedtsyrer med ulige antal C-atomer kan tyde på køer med SARA (sur vom).
Effekten af forskellige fedtsyrer og fedtsyregrupper på den humane sundhed er under diskussion, og forsk-ningen er ikke entydig. Dog viser den aktuelle viden, at der sandsynligvis kan opnås en sundhedsfremmende profil i mælkefedtet ved at øge indholdet af umættede fedtsyrer og reducere andelen af palmitinsyre. Tek-nologisk vil det samtidig bidrage til smør med en blødere og mere smørbar tekstur. Flere umættede fedtsyrer og mindre palmitinsyre i mælkefedtet kan muligvis også påvirke smagen af osteprodukterne.
Resultaterne fra godt 3,5 mio. mælkeanalyser viser, at faktorerne race, laktationsstadie, laktationsnummer, produktionsform og måned alle har effekt på mælkens fedstyresammensætning. Udbinding og store mængder frisk græs i rationen ændrer fedtsyreprofilen i retning af flere umættede fedtsyrer og mindre pal-mitinsyre. Data viser også, at Jersey adskiller sig fra de øvrige racer ved en højere andel mættede fedtsyrer og en tilsvarende lavere andel umættede fedtsyrer. Resultaterne viser desuden, at fedtmobilisering i starten af laktationen påvirker fedtsyreprofilen i mælken, og andelen af monoumættede fedtsyrer er størst i perio-den, hvor køerne mobiliserer. Endelig viser data avlsmæssig variation for de enkelte fedtsyregrupper, og det er derfor muligt at påvirke sammensætning af mælkefedtet gennem avl.
Data fra mælkeanalyserne er anvendt til en foreløbig beregning af arvbarheden hen over laktationen, og de beregninger viser, at alle fedtsyrekategorier har en genetisk variation og enkeltfedtsyrerne har arvbarheder på højde med den samlede fedtydelse. Det betyder arvbarheder i intervallet 0,25-0,44 afhængig af race og paritet. De genetiske sammenhænge varierer betydeligt gennem laktationen og er påvirket af den øgede kropsmobilisering i de første måneder efter kælvning. En anvendelse af fedtstyrebestemmelserne i avlen vil derfor kræve en opdeling af laktationen i mindst to perioder. En eventuel fremtidig selektion for fedtsyre-grupper bør desuden ske ved at konstruere et indeks, som samtidig kan sikre fremgang for de ønskede fedt-syregrupper (mono- og polyumættede samt kortkædede fedtsyrer) og tilbagegang for den mættede pal-mitinsyre, samt sikre at uønskede sideeffekter for andre egenskaber ikke indtræffer.
Perspektiverne i at avle efter ændret fedtsyreprofil i mælken afhænger af, om mejerierne og markedet i fremtiden vil afregne mælken for de enkelte fedtsyrefraktioner frem for betaling for den samlede fedtfraktion som i dag. Samlet kan det konkluderes, at der er et betydeligt avlsmæssigt potentiale, og hvis der kommer et dansk marked for mælkeprodukter med særlige egenskaber, vil det være oplagt at ændre det avlsmæssige niveau i gunstig retning og samtidigt udnytte de fodringsmæssige muligheder for at producere mælk med en sundhedsfremmende fedtsyreprofil. Datamaterialet her og fedtsyremåling af samtlige mælkeprøver i ydelseskontrollen giver en unik position i forhold til det
Large scale screening of milk fatty acid profile: new possibilities for dairy product development
In the Danish dairy industry milk fatty acid (FA) composition has an increasing interest to develop products following new consumers’ trends. Furthermore, FA profiles of the milk have the potential to be used as a management tool to predict eg the energy balance in the cow. The golden standard to measure milk fat composition is based on gas chromatography, however this method is time consuming and costly. Therefore, to be able to provide the Danish dairy industry with routine milk FA composition data, mid-infrared spectroscopy prediction models have been applied since May 2015. [Read more in attached abstract
Norwegian dairy farmer's preferences for breeding goal traits and associations with herd and farm characteristics
The aims of this study were to investigate variation and clustering in breeding goal trait preferences among Norwegian dairy farmers and to identify factors with a systematic influence on their preferences. An internet-based questionnaire was sent out to dairy farmers connected to the Norwegian co-operative breeding organization Geno (N = 8222), of which 10.8% answered (N = 888). Of the 15 suggested traits fertility had the highest overall ranking, while parasite resistance and methane emission had the lowest. Four distinct preference clusters were identified by the means of cluster analysis, of which two had a high preference for milk production. Differences in terms of farm and herd characteristics between clusters suggests a mixture of systematic and
intrinsic effects on breeding goal trait priorities. This study shows that Norwegian dairy farmers’ preferences for breeding goal traits fall into four distinct clusters, both affected by herd and farm characteristics along with intrinsic value
The fatty acid profile of the milk is measured on all cows in Denmark
The fatty acid profile of the milk is measured on
all cows in Denmark
The GUDP financed project SOBcows has in collaboration with RYK (Registration and Milk recording) collected a detailed fatty acid profile
on all the cows, which are in the Danish milk recording system. In the past 16 months during 2015 and 2016, we have collected
approximately 3.5 million milk samples.
The samples were analyzed with the Foss application note 64, which registers 11 fatty acids or fatty acid groups. It is the first time that the
milk fat from so many cows is registered in such detail. The data can be used to exploit the possibilities for genetic selection and feeding
strategies to change the fatty acid profile in the milk into a desired direction.
The initial genetic analysis showed that the heritability across the lactation was between 0.25 and 0.44 depending on the breed and parity of
the cow. During the lactation, the cow mobilizes fat especially in the first part of the lactation to fulfill the energy requirement to produce
milk. This was reflected in the change of the genetic variation over the lactation. This implies that if you would like to change the fatty acid
profile of the cows by genetic selection you need to divide lactation in at least two periods.
Additionally, the collected data showed that the feeding regime of cows had significant influence. Milk from organic farms shows a much
larger variation in saturated fatty acids over the year compared to conventional farms. Especially when cows are going outside on fresh grass,
the favorable unsaturated fatty acids increase, while the unfavorable fatty acid, like C16:0 decreases.
At the moment there is still an ongoing discussion on the effects of the different fatty acids on human health. With today’s knowledge, one
would like to have fat with a reduced saturated fatty acid content and increased unsaturated fatty acid content. However, it is more
complicated because the chain length of the (unsaturated) fatty acids also has an influence on human health, where the short chain fatty acids
lean towards a positive to neutral effect, the middle chain fatty acids, especially C16:0 lean towards the negative side. With regard to human
nutrition it is most likely that changes in the fat composition would benefit those products with high fat content, like butter and cheese. As an
example, on the English market a special milk with lower saturated fat content than the regular milk is sold.
In conclusion we showed that when there is a Danish market for milk products with special fatty acid profiles we will be able to change the
milk fatty acid profile, both by genetics and feeding into the desired direction
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