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

The effect of feeding sequence on fat concentration in milk

International audienc

Facteur de variation du taux butyreux du lait: effet de l'ordre de distribution des aliments

National audienc

Vitamin B9 and B12 contents in cow milk according to production system

International audienceThe factors of variation for vitamin B9 and B12 content in cow's milk have not been studied intensively. Nevertheless, these vitamins are of great nutritional interest and the consumption of a large glass of milk could provides up to 15% of the recommended daily allowances for vitamin B9 and 90% for vitamin B12. The objective of this study was therefore to describe the variability of the levels of vitamins B9 and B12 in 100 bulk milk samples produced under four French major production systems (plain or mountain and forage system based on grass or maize silage). For each production system, milk was sampled and analyzed at five periods over the year 2008. The characteristics of these milks differed according to the production system. The highest levels of vitamin B9 were generally associated with diets based on hay in the winter period and with diets based on pasture during the grazing season. Conversely, the highest levels of vitamin B12 were principally measured in milks produced with diets based on maize silage

Co-construction of an assessment method of the environmental sustainability for cattle farms involved in a Protected Designation of Origin (PDO) cheese value chain, Cantal PDO

In France, numerous Protected Designation of Origin (PDO) cheese value chains have revised their specifications to address environmental protection, particularly at the farm level. In this stage, it is nevertheless impossible to state whether the proposed modifications may ensure the sustainability of environmental protection as no environmental sustainability diagnostic has been conducted. The aim of this study is to construct an assessment method for the Cantal PDO farms.A multi-criteria assessment approach was implemented in the following 5 steps: definition of the framework of the study, determination of the principles and criteria, definition of the indicators, aggregation of all elements of the assessment, and finally, test of the assessment method on farms. Focus groups meetings were organised for the first four steps. The panel discussions were based on data obtained from both the literature and surveys of stakeholders operating in the value chain and within the territory.The obtained assessment method comprises 4 principles characterised by 33 indicators. The most important principle (45%), management of grassland resources, is a key economic and environmental point of the studied farms. It reflects the necessary intensive use of grass by the animals in the PDO farms. Few existing methods addressed this principle that required the design of several new indicators. The second principle, impact of agricultural practices (25%), is often included in environmental sustainability assessment methods The adopted indicators are, thus, drawn from existing methods and adapted to the context of the farms studied. The management of the farm buildings and the landscape principle (18%) is often considered in social sustainability. Its role in environmental sustainability can be explained by its strong link with the image of PDO products. Primarily drawn from the literature, the used indicators have been extended to make the assessment method as objective as possible. Finally, the management of local, energy and water resources principle has the lowest weighting (12%). This can be explained by the limited number of indicators.This assessment method was constructed for the Cantal PDO farms by considering their environment and particularities. In consequence, the stakeholders have taken ownership of it. It could be used by other ruminant systems based on grassland. The development of numerous indicators enhanced the pool of existing indicators. This assessment method was sensitive and allowed for the discrimination between farms

Tanker milk variability in fatty acids according to farm feeding and husbandry practices in a French semi-mountain area

The objective of this study was to relate farm feeding practices in different production systems to milk fatty acid (FA) composition on the scale of round tankers. Milks from 10 collection rounds in the French department of the Haute-Loire (10 to 36 herds per collection round) were sampled twice and three times during winter and grazing periods, respectively. The collection rounds were principally characterised by the forage system (grass or maize silage). Nine variants of milk production conditions were defined: four for the winter feeding period (W1 to W4) and five for the grazing period (G1 to G5). Over the year rumenic acid was positively correlated with vaccenic acid (r = 0.99), all the other trans and c11 isomers of C18:l, oleic acid (r = 0.79), linolenic acid (r = 0.82) and eicosapentaenoic acid (C20:5n-3, EPA). The milk fat from cows grazed on grass had a higher proportion of total trans FA (including trans C18:l, non-conjugated C18:2 and c9t11-CLA) and total cis C18:1, and a lower proportion of medium-chain saturated FA (−9.50 g·100 g−1 for C16:0 between G5 vs. W1) and monounsaturated FA (mainly c9-C16:l) than that from grass silage-based (and concentrate-supplemented) diets. Also, anteiso-15, C18:0, c9-, t6+7+8-, t9-, t11- and t13+14-C18:1, c9t11-CLA (r = 0.65), t11c15-C18:2, C18:3n-3 (r = 0.68) and EPA (r = 0.64) were positively linked to permanent grassland forages (green or conserved) on the scale of the year. During winter, trans (t6+7+8, t10, t12 and t13+14) and cis (c12, c13 and t16+c14) isomers of C18:1 were positively correlated with the proportion of maize silage in the diet (r = 0.47 to 0.91). The wide range of milk FA composition from the rounds observed in this study was closely linked to the variants in feeding and husbandry conditions. Our data confirm the strong effect of nutritional factors on milk FA composition of tanker milk shown in experimental trials.L’objectif de cette étude était, à l’échelle de laits de tournées, d’établir des relations entre les pratiques d’alimentation et les conduites d’élevage de différents systèmes de production et la composition en acides gras (AG) de ces laits. Les laits de 10 tournées dans le département français de la Haute-Loire (10 à 36 troupeaux par tournée) ont été prélevés, respectivement, deux et trois fois pendant l’hiver et la période de pâturage. Neuf variants des conditions de production des laits ont été définis : quatre pour la période hivernale (W1 à W4) et cinq pour la période de pâturage (G1 à G5). Au cours de l’année, l’acide ruménique était positivement corrélé à l’acide vaccénique (r = 0.99), à l’ensemble des autres isomères trans et c11 du C18:l, aux acides oléique (r = 0.79), linolénique (r = 0.82) et EPA. La matière grasse laitière provenant du pâturage avait une proportion plus élevée en AG trans totaux (incluant les C18:1 trans, les C18:2 non conjugués et le CLA-c9t11) et en C18:1 cis totaux, et une proportion plus faible en AG saturés à chaîne moyenne (−9.50 g·100 g−1 pour le C16:0 entre G5 et W1) et d’AG monoinsaturés (principalement C16:l-c9) que celle produite à partir des rations àbase d’ensilage d’herbe (et supplémentées en concentré). De plus, l’antéiso — 15, le C18:0, le C18:1-c9, les isomères t6+7+8, t9, t11 et t13+14 du C18:l, le CLA-c9t11 (r = 0.65), le C18:2-t11c15, le C18:3n-3 (r = 0.68) et l’EPA (r = 0.64) étaient positivement liés aux fourrages de prairie permanente (verts ou conservés) à l’échelle de l’année. Durant l’hiver, les isomères trans (t6+7+8, t10, t12 et t13+14) ou cis (c12, c13 et t16+cl4) du C18:l étaient positivement corrélés à la proportion d’ensilage de maïs dans la ration (r = 0.47 à 0.91). La grande variabilité de la composition en AG des laits des tournées dans cette étude était fortement liée aux variants d’alimentation et aux conditions d’élevage. Nos données confirment l’effet important des facteurs nutritionnels sur la composition en AG des laits de grand mélange, démontré au cours d’études expérimentales

La sécrétion de riboflavine dans le lait de vache varie selon la composition de la ration et la saison

National audienceIn ruminants, B-vitamin supply from the diet and synthesis by the rumen microflora is considered sufficient to avoid deficiency. Nevertheless, factors affecting their concentrations in milk have never been studied in-depth, even if dairy products are among the best contributors of several vitamins (especially riboflavin) in human nutrition. We compared, during a year, riboflavin concentrations in bulk tank milks from 20 groups of 5 commercial farms divided among production systems mainly characterized by the forage nature (grass or maize silage). Riboflavin concentrations were greater in milks from grass-based than maize silage systems (1.91 vs 1.70 mg.L-1, P<0.001). Moreover, they increased during summer (from 1.71 to 1.99mg.L-1,P<0.001) whatever the feeding system. These differences were largely explained by a dilution effect due to the level of the milk yield but the mean amount of riboflavin secreted in milk per cow per day was higher when cows were fed a diet rich in maize silage by comparison to a herb-based diet (42.5 vs 33.4μg.d-1 , respectively, P< 0.001). Conversely to what should be thought, riboflavin concentrations in milk are submitted to variations, and more interestingly regulations, that influence the global nutritional quality of milkEn raison de leur double origine alimentaire et microbienne ruminale, la disponibilité en vitamines B chez les ruminants est considérée pouvoir couvrir les besoins de ces animaux. C’est la raison pour laquelle, la variabilité de leurs concentrations dans le lait n’a jamais été explorée, même si le lait et les produits laitiers sont parmi les premiers contributeurs de certaines vitamines (dont la riboflavine) en nutrition humaine. Nous avons déterminé les concentrations en riboflavine dans des laits de tournées simulées correspondant à 20 groupes de 5 fermes commerciales caractérisés par leur système fourrager (basé sur l’herbe ou l’ensilage de maïs). Les concentrations de riboflavine étaient supérieures dans les laits issus des systèmes à base d’herbe par rapport à ceux utilisant préférentiellement le maïs (1.91 vs 1.70 mg.L -1 , P<0 . 001). Elles ont augmenté également pendant l’été quel que soit le système considéré (de 1.71 à 1.99 mg.L -1 , P<0 . 001). Ces différences s’expliquent principalement par un effet de dilution lié à la quantité de lait produite ; cependant, la quantité moyenne de riboflavine sécrétée dans le lait par vache et par jour était supérieure lorsque les vaches recevaient une ration à base d’ensilage de maïs que lorsqu’elles recevaient une ration à base d’herbe (respectivement 42.5 vs 33.4 μg.j -1 , P<0.001). Contrairement au concept couramment admis, la concentration de riboflavine du lait est variable, et de manière encore plus intéressante, elle semble être régulée, ce qui impacte la qualité nutritionnelle globale du lait et des produits laitier