80 research outputs found
Authentication of cow feeding and geographic origin on milk using visible and near-infrared spectroscopy.
International audience; The ability of near-infrared spectroscopy to trace cow feeding systems and farming altitude was tested on 486 bulk milk samples from France and northwestern Italy. Milks were grouped into feeding systems according to the main forage in the diet. Partial least square discriminant analysis correctly classified 95.5, 91.5, and 93.3% of pasture versus maize silage, hay, and fermented herbage feeding systems, respectively. Discrimination was slightly less successful when diets with large proportions of the nondominant forage were included in each group. Near-infrared spectroscopy correctly discriminated no-pasture from pasture milk, even with only 30% of pasture in the diet (5.4% cross-validation error), and the error stabilized when pasture exceeded 70% (2.5% error). Near-infrared spectroscopy did not reliably trace milk geographic origin when the feeding system effect was isolated from the altitude effect. These findings may be usefully exploited for the authentication of dairy products
Prediction of bulk milk fatty acid composition based on farming practices collected through on-farm surveys
International audience; The aim of this study was to predict the fatty acid (FA) composition of bulk milk using data describing farming practices collected via on-farm surveys. The FA composition of 1,248 bulk cow milk samples and the related farming practices were collected from 20 experiments led in 10 different European countries at 44 degrees N to 60 degrees N latitude and sea level to 2,000 m altitude. Farming practice-based FA predictions [coefficient of determination (R-2) >0.50] were good for C16:0, C17:0, saturated FA, polyunsaturated FA, and odd-chain FA, and very good (R-2 >= 0.60) for trans-11 C18:1, trans-10 + trans-11 C18:1, cis-9,trans-11 conjugated linoleic acid, total trans FA, C18:3n-3, n-6:n-3 ratio, and branched-chain FA. Fatty acids were predicted by cow diet composition and by the altitude at which milk was produced, whereas animal-related factors (i.e., lactation stage, breed, milk yield, and proportion of primiparous cows in the herd) were not significant in any of the models. Proportion of fresh herbage in the cow diet was the main predictor, with the highest effect in almost all FA models. However, models built solely on conserved forage-derived samples gave good predictions for odd-chain FA, branched-chain FA, trans-10 C18:1 and C18:3n-3 (R-2 >= 0.46, 0.54, 0.52, and 0.70, respectively). These prediction models could offer farmers a valuable tool to help improve the nutritional quality of the milk they produce
Effet de la forme de présentation de l'orge sur la production et la composition du lait de vache
International audienc
The effect of feeding sequence on fat concentration in milk
International audienc
Facteurs de variation de la numeration cellulaire du lait en exploitation
International audienc
Facteurs de variations du rapport des teneurs en matiÚres grasses et protéiques du lait de vache : étude dans les exploitations des Alpes du Nord
Soixante deux exploitations laitiĂšres des Alpes du Nord ont fait lâobjet dâune enquĂȘte dĂ©taillĂ©e concernant Ă la fois la structure de lâexploitation et du troupeau, la qualitĂ© des fourrages et les pratiques alimentaires hivernales et estivales. Ces donnĂ©es ont permis dâanalyser les variations de la composition chimique du lait dâune exploitation Ă lâautre, et en particulier du rapport taux butyreux/taux protĂ©ique. Celui-ci a prĂ©sentĂ© des variations trĂšs importantes dâune exploitation Ă lâautre et dâun mois Ă lâautre. Selon les exploitations, ces variations sont dues surtout Ă celles du taux butyreux (cas le plus frĂ©quent), ou plutĂŽt Ă celles du taux protĂ©ique. Les diffĂ©rences de niveau de ce rapport dâune exploitation Ă lâautre sont difficiles Ă expliquer par les seules donnĂ©es disponibles : en particulier, compte tenu du type des vaches prĂ©sentes (Abondance, Tarine et MontbĂ©liarde), lâeffet de la race ne semble pas prĂ©pondĂ©rant. Ce sont les exploitations qui maĂźtrisent le mieux lâalimentation hivernale et estivale des animaux (et qui prĂ©sentent par ailleurs des effectifs importants et stables au cours de lâannĂ©e) qui ont prĂ©sentĂ© les rapports les plus stables au cours de lâannĂ©e.A detailed survey was conducted on 62 dairy farms located in the northen Alpes to determine some of the factors in herd management that influence milk fat content: protein content ratio (FC/PC). Large variations were noted between farms (1.10 to 1.25) and between months in the same farm. Depending on the farms, these variations result mainly either from differences of fat content (more frequent situation) or from differences of protein content. Differences of FC/PC among farms were not well related to the different herd characteristics avalaible. Low FC/PC variations between months in the same farm were associated with good feeding practices (during winter and summer)
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