Search

International audience; Elevation of mean air temperature related to climate change speeds up plant maturity, which influences mostly forage feed value. The objective of the study was to assess variation in hay quality harvested over 32 years at the same experimental site, and whether feed value is better predicted by combining agro-climatic variables with chemical composition. From 1979 to 2010, the in vivo digestibility (OMd) and voluntary dry matter intake (VDMI) of 271 hays, harvested during the first vegetation cycle on permanent grasslands, were measured in sheep. Over 32 years, the mean air temperature between February and August increased significantly by 1.34 degrees C. Cutting date was advanced by 6 days, but the average sum of temperature at cutting (ST) increased significantly by 13%. Crude protein (CP) content declined (-22%, p < .001), crude fibre content increased (+8%, p < .001), OMd decreased (-3%, p = .012) and VDMI increased (+9%, p = .011). Changes in the chemical composition and OMd were consistent with the increase in ST. Finally, the prediction of OMd from CP and crude fibre contents (R-2 = .57, RMSE = 2.99) was slightly improved by the addition of ST and hay drying time (R-2 = .60, RMSE = 2.83). Climate change may have a negative indirect effect on hay quality if an earlier cutting date does not compensate for its effect on the faster maturation of the plants. Moreover, agro-climatic criteria could help to monitor and predict hay quality in relation to intra- and inter-annual climatic changes.

International audience; Long-term monitoring of animal activity can yield key information for both researchers in ethology and engineers in charge of developing precision livestock farming tools. First, a barn is segmented into delimited areas (e.g. cubicles) with which an activity can be associated (e.g. resting), then a real-time location system (RTLS) can be used to automatically convert cow position into behaviour. Working within the EU-PLF project, we tested a system already able to determine basic activities (resting, moving, eating…) and logged a “big data” set of billions of data points (123 days 190 cows 1 location-per-second readings). We then focused on integrating image analysis techniques to help visualise and analyse the dataset, first to validate the data and then to enrich the information extracted. The algorithm developed using freely available tools quickly confirmed the ability of the system to determine cows' main activities (except drinking behaviour), even with 11% of positions missing. The good localisation precision (16 cm) made it possible to enrich the time-budget with new activities such as using brushes and licking mineral blocks. For both activities, using visual observations as gold standard, activity profiles with excellent sensitivity (nearly 80%) were extracted. This validation procedure is both necessary and generalisable to other situations. The improvement of biological information contained in such data holds promise for people designing alarm devices and health and welfare indicators for farmers and/or vets.

In mountain areas, hays are the main forage in winter diets for livestock. Barn-dried hays can be an alternative to traditional hays, which are generally characterized by a low feed value. The aim of this study was to compare the feed value of barn-dried hays with that of the fresh forage from a permanent meadow. The study was carried out over three periods during the first growth cycle of the meadow&rsquo, s vegetation (from 30 May to 3 June, from 13 to 17 June, and from 27 June to 1 July). Fresh forage and barn-dried hays of the same fresh forages were tested for dry matter digestibility (DMD), organic matter digestibility (OMD), and voluntary intake (VI). Both types of forage obtained each period were tested with an interval of 15 days. Chemical composition and OMD of forages did not change (p &gt, 0.05) according to the feeding method. However, the DMD values for barn-dried hays were higher (p &lt, 0.05) than for fresh forages at the end of the cycle. VI and digestible organic matter intake of barn-dried hays were higher (p &lt, 0.05) than that of fresh forages. In conclusion, barn-dried hays obtained from permanent grasslands presented a higher feed value than fresh forages.

International audience; Milk fat content and its fatty acid (FA) profile are important components of both the milk nutritional and technological qualities. The present study was conducted to evaluate the influence of calf presence during milking and of cow breed on milk yield, gross composition, FA profile and milk lipolytic system. A total of 30 Prim’Holstein (PH) and Salers (S) primiparous lactating cows were milked in the presence or absence of their calves during 210 days of lactation and bulk milks were collected during 6 weeks in a restricted part of the whole experimental period for analyses. Calf presence increased milk yield and decreased the milk fat content in S cows, whereas no difference was observed for the PH cows. The PH milk had higher levels of short- and medium-chain FA and C18:2 n−6, whereas S milk had higher levels of C18:2 cis-9,trans-11 (conjugated linoleic acid, CLA), C18:3 n−3 and C20:5 n−3. The S milk also had higher initial lipolysis. Calf presence during milking increased the C16:0 percentage and decreased C18:0, C18:2 n−6, C18:3 n−3, total polyunsaturated FA percentages in milk fat. Calf presence decreased the milk trans-C18:1 level only in S cows. Cis-9,trans-11-CLA level increased in the calf presence in PH cows, whereas it decreased in S cows. Calf presence during milking increased milk lipolysis after 24 h only in the PH cows. Calf presence during milking had significant effects on the milk yield, gross and fine composition, and lipolysis but these effects differed according to the breed.

International audience; The phospholipid and sphingolipid composition of milk is of considerable interest regarding their nutritional and functional properties. The objective of this article was to determine the lipid composition of the milk fat globule membrane (MFGM) of milk from cows fed a diet rich in polyunsaturated fatty acids. The experiments were performed with 2 groups of 6 cows feeding on (i) maize silage ad libitum (+ grassland hay, mixture of cereals, soyabean meal) or (ii) the maize silage-based diet supplemented with extruded linseed (bringing a lipid proportion of 5% of dry matter). The phospholipid and sphingolipid composition of the MFGM was determined using HPLC/ELSD. The fatty acid (FA) composition of total lipids and phospholipids was determined using GC. As expected, the linseed-supplemented diet decreased the saturated FA and increased the unsaturated FA content in milk fat. MFGM in milk from cows fed the diet rich in polyunsaturated FA resulted in (i) a higher amount of phospholipids (+ 18%), which was related to a smaller size of milk fat globules (ii) an increase of 30% (w/w) of the concentration in sphingomyelin, (iii) a higher content in stearic acid (1.7-fold), unsaturated FA (1.36-fold), and C18:1 trans FA: 7.2 +/- 0.5% (3.7-fold). The MFGM contained a higher concentration of unsaturated FA (C18:1, C18:2, and C18:3) and very long-chain FA (C22:0, C23:0, C24:0, EPA, DHA) compared with total lipids extracted from milk. The technological, sensorial, and nutritional consequences of these changes in the lipid composition of the MFGM induced by dietary manipulation remain to be elucidated.

The fatty acid composition of milk triacylglycerols (TAGs) can be modified to improve their nutritional properties and the long-term health of consumers. However, the consequences of an increase in unsaturated fatty acid (UFA) content on the physical properties of milk TAGs remain to be elucidated. This study aimed at comparing the crystallisation properties and melting behaviour of control vs. UFA-enriched milk TAGs using the coupling of time-resolved synchrotron X-ray diffraction and differential scanning calorimetry on cooling and then heating at 3 °C/min. On cooling from the melt, high crystallisation temperature (HCT) TAGs solidify from 15.8 °C in α 2L (45–49 A) structures, then low crystallisation temperature (LCT) TAGs form α 3L structures with a higher thickness (75.5 A vs. 71.5 A) and a delay (8.5 °C vs. 12.1 °C) for UFA-enriched TAG. On heating, melting of TAGs crystals and formation of 3L 2 (64.7–80.1 A) and β′ 2L f (40–44 A) crystals associated with polymorphic reorganisations have been characterised. The organisation of TAG molecules in their liquid state revealed a higher thickness for UFA-enriched TAGs as compared to control TAGs. Such results improve the knowledge about the mechanisms of TAG crystallisation as a function of their FA composition and are important for the technological utilisation of UFA-enriched TAGs in food products.

Les modèles mathématiques tiennent de nos jours une place importante dans les recherches en biologie. En productions animales, notamment dans le domaine de la croissance des bovins, de nombreux modèles ont été élaborés. Leur degré de complexité et leur niveau d’intégration des connaissances des mécanismes varient notamment en fonction des objectifs qui leur sont assignés. La prise en compte de processus biologiques à des échelles fines, d’où un niveau d’agrégation faible du modèle, peut constituer une source d’incertitude sur la valeur des paramètres employés, et donc nuire au caractère opérationnel d’un modèle. Cet article classe et décrit dans un premier temps les différents types de modèles de croissance de bovins. Puis un modèle dynamique et mécaniste, que nous avons développé, fait l’objet d’une description détaillée. Ce modèle se veut suffisamment simple pour pouvoir être utilisé pour la prévision de la croissance des animaux en fonction de l’alimentation, tout en intégrant une formalisation mathématique des processus biologiques. Les résultats issus de ce modèle ont été confrontés avec des données expérimentales concernant des génisses Salers. Cette comparaison montre une assez bonne adéquation entre données simulées et expérimentales. Toutefois, pour certaines variables, telles que les lipides et les dépôts adipeux, des améliorations, notamment de la formalisation de nos connaissances, apparaissent nécessaires. L’intégration de tels modèles dans des outils de recommandations alimentaires est également discutée., Mathematical models play nowadays an important role in research in biology. In the field of animal production, for instance beef cattle growth, many models have been elaborated. Their degree of complexity and their level of integration of knowledge on mechanisms vary according to the objectives they are assigned. Considering biological processes on a fine scale, leading to a low aggregation level of the model, which may generate uncertainty in the value of the parameters, hamper the future applications of a model. This paper first deals with a classification and a description of the different types of beef cattle growth models. A dynamic and mechanistic model we have developed is then described. This model attempts to be simple enough in order to be used for the prediction of animal growth as a response to feeding, yet integrating a mathematical formalization of biological processes. Results from this model have been tested against experimental data on Salers heifers. This comparison shows globally a good agreement between simulated and observed data. However, for some variables, like lipids and adipose tissues, the model needs to be improved, for instance in the formalization of our knowledge. The integration of such models in feed allowances tools is also discussed.

ei saatavilla

The relation between the useful material content (protein+fat content) of milk and cheese yield was analyzed on 189 manufactures of pressed uncooked cheeses. These manufactures were realized under controlled conditions in the same experimental cheese dairy, within the frame- work of eight different experiments, from milks of high hygienic quality (cows free of clinical mas- titis) partially skimmed so as to have a fat/protein ratio of 1.15. The fat+protein content of manufactured milks varied from 55 to 85 g.kg -1 . The relation between fat+protein content and cheese yield was lin- ear for this wide range of variation. Fat+protein content accounted for 77% of fresh yield and 87% of dry matter yield variability. Once the effect of fat and protein contents have been taken into account, other milk parameters (pH, κ-casein variants) may have a significant effect on cheese yield, but in a marginal way. milk / fat and protein contents / cheese yield

The transfer of monoterpenes and sesquiterpenes from forages into milk fat was stud- ied in a group of cows fed successively with forages containing high and low amounts of these sub- stances. In a first 24-d period the cows received 11 kg of a cocksfoot hay containing low quantities of monoterpenes and sesquiterpenes. In a second 36-d period, 3 kg of the cocksfoot were replaced by 3 kg of yarrow, a plant rich in terpenoids. In a third 24-d period the cows returned to the cocksfoot- based diet they were fed in the first period. The quantities of monoterpenes and sesquiterpenes des- orbed from the milk fat were measured by dynamic headspace - gas chromatography - mass spec- trometry. Results showed that the quantities of monoterpenes had increased by the first milking carried out 8 h after ingestion of yarrow, whereas the increase in the quantities of sesquiterpenes was observed only after the third milking, 32 h after the diet change. The maximal quantities of monoterpenes and sesquiterpenes were measured after 4 d of the yarrow-enriched diet, after which the total quantities decreased, despite the constant supply of yarrow. Four days after discontinuing yarrow the amounts of monoterpenes and sesquiterpenes desorbed from the milk fat reverted to those measured during the first period. traceability / type of feeding / terpenoid analysis / purge-and-trap / gas chromatography-mass spectrometry

Forty-two multiparous dairy cows of 3 different breeds (Holstein, Montbeliarde and Taren- taise) were divided into 2 groups (A and B) according to β- and κ-casein genetic variants, and were fed 3 floristically different types of hay (cocksfoot, rye-grass-rich and native mountain grassland hay) according to a 3 〈 3 Latin-square design. The milk produced by these cows was used to make Saint-Nectaire-type cheese, using identical and controlled cheesemaking techniques. The cheeses made from cocksfoot diet milk had higher pH (P < 0.01), lower fat in dry matter ( P < 0.05), more elas- tic texture and a strong cellar odour ( P < 0.1). The cheeses produced from the milk of cows fed native mountain grassland hay exhibited a slightly gritty and yellower body, and had a pronounced vinegar and cabbage odour. Rheological analysis confirmed the beneficial effect of the B variant of β- and κ-caseins on milk rennet clotting ability. This effect did not seem to affect the cheeses because they could not be distinguished by any of their sensory characteristics. milk / cheese / genetic variant / diet

This study assessed the extent to which eating solid foods and social contacts influence nibbling objects and improve the welfare of veal calves. Animals were fed milk replacer only vs. supplemented with solid foods and were housed in individual stalls vs. together in pens. Time budget, reactions to handling in a weighing machine, growth, health (length of medical treatments) and abomasal lesions were assessed. In addition, chronic activation of the hypothalamo–pituitary–adrenocortical axis was evaluated after ACTH and CRF challenges, and that of the sympathetic nervous system, through activities of catecholamine-synthesising enzymes. The provision of solid foods reduced time spent nibbling objects and being inactive in proportion to and at the time of the increase in time spent eating and chewing. The calves housed together in pens had higher basal cortisol levels and they reacted to weighing. Health and physiological indices of chronic stress did not vary with feeding or housing conditions. It is concluded that nibbling in veal calves derives at least in part from a lack of development of feeding behaviour appropriate to ruminants. There was no clear evidence of poorer welfare due to feeding on milk replacer only or individual housing, but calves reared in groups seemed more stressed by handling than calves reared in individual stalls.

The reprocessing-conditioning-recycling (RCR) strategy experimented by COGEMA drastically reduces the volume and the radiotoxicity of ultimate residues to be disposed. Technical improvements at the La Hague reprocessing plant, including compaction of hulls and end-fittings, decreases the volume of long-lived residues to less than 0.5 m3 per t HM (heavy metal), far less than 2 m3 yielded for direct disposal of spent fuel. Moreover, a Universal Canister of same shape and dimensions as a glass canister for vitrified fission products has been designed to standardize these residues. Respectively, the new management of short-lived technological wastes will lessen their volume from 1.4 m3 per t HM in 1995 down to around 0.6 m3 by 2000.

Cinquante-quatre vaches laitieres multipares en milieu de lactation ont ete utilisees dans un essai en carre latin 3x3. Pendant chaque periode de 3 semaines, les animaux ont recu une ration de fourrage isoenergetique, a base d'ensilage de ray-grass anglais (11 kg de matiere seche/j), de foin de seconde coupe de dactyle (13 kg de matiere seche/j) ou d'ensilage de mais (11 kg de matiere seche/j). Chaque ration a ete complementee avec la meme quantite d'un melange d'orge, de tourteau de soja et d'uree dont les proportions ont ete calculees de maniere a ce que les apports azotes soient voisins et non limitants dans les 3 traitements. Les vaches recevant de l'ensilage d'herbe ont produit respectivement 0,4 (P > 0,05) et 1,9 kg/j (P < 0,01) de lait de plus que celles recevant de l'ensilage de mais ou du foin, mais leur lait a ete significativement plus pauvre en proteines et en caseines. Ce resultat est lie a un partage de l'energie ingeree plus favorable a la production de lait qu'a la reconstitution des reserves corporelles avec la ration a base d'ensilage d'herbe. Le rapport caseines/proteines, la teneur en calcium, le pH et les caracteristiques rheologiques du lait n'ont pas ete significativement differents selon le type de ration de base.

The present study was conducted in order to evaluate the effects of calf presence during milking and cow breed on milk fatty acid (FA) profile. 30 Prim’Holstein (H) and Salers (S) primiparous lactating cows were milked in the presence (CP) or in the absence (CA) of their calves, during the 9 months of lactation. Milk FA profile was significantly influenced by breed: 4:0, 12:0, 18:2 n-6 and cis-18:1 had higher concentrations in milk from H cows, whereas 14:0, 18:3 n-3, cis-9,trans-11-CLA and trans-18:1 had higher concentrations in milk from S cows. The presence of the calf during milking also had an important effect: it decreased the milk fat content, as well as 18:0, 18:2 n-6, 18:3 n-3 and trans-18:1 levels and it increased 16:0 level. Cis-9,trans-11-CLA concentration increased in the presence of the calf, for H cows, whereas it decreased for S cows.

Increasing the unsaturated fatty acid (UFA) content in milk fat is of primary importance to improve the long-term health of consumers. However, such changes can affect the crystallization properties of milk triacylglycerols (TAG) and their functional properties. The objectives of this study were to investigate the crystallization properties of milk fat as a function of its FA composition and emulsion droplet size upon storage at refrigerated temperature. UFA-enriched TAG were obtained using cow diet supplemented with linseed oil and compared to control TAG. Homogenization was used to vary the size of emulsion droplets, from 1.7 to 0.2 μm. The crystallization properties of TAG were studied using synchrotron X-ray diffraction coupled to differential scanning calorimetry. We characterized the coexistence of several solid fat phases with a liquid phase, the characteristics of which depended on the temperature, FA composition and droplet size. The enrichment in UFA from 29 to 51 wt.% led to a decrease in the enthalpy ratio (ΔH partial /ΔH total ) from 64 ± 4 to 54 ± 4% at 4 °C and to the formation of 2 L (41.8 A) structure with β 1 , β′ 1 , and β′ 2 polymorphic forms while 2 L (39.5 A) and 3 L (56.6 A) structures with β 1 , β 2 , β′ 1 and β′ 2 polymorphic forms were formed with control TAG. The size of the emulsion droplets also affected the structural and thermal properties of milk TAG. Such experiments increased the knowledge about the crystallization properties of TAG dispersed in emulsion and will be useful for industrial applications and the development of UFA-enriched dairy products with improved nutritional properties.

International audience; A large number of in vivomeasurements of forage digestibility and intake is difficult to obtain, especially for permanent grasslands that cannot easily be studied outside their location. A study was conducted to estimate the variability of forage in vivo digestibility and voluntary intake in sheep between and within experimental stations. Bales from two permanent grassland hays harvested on the same plots were delivered to five experimental stations. Samples were analysed for ash, crude protein and neutral detergent fibre. Digestibility and intake trials for both hays were performed simultaneously in the five experimental stations. Repeatability (error within laboratories) and reproducibility (error between laboratories) for these measures were assessed. Chemical composition variability between forage samples at each station was important for ash. For dry matter digestibility (DMD), organic matter digestibility (OMD) and neutral detergent fibre digestibility (NDFD), the variability between animals was greater than between stations and repeatability and reproducibility values were close (0.04 and 0.05 respectively for OMD). For dry matter intake (DMI) and digestible organic matter intake (DOMI) the variability of the measurement was more than three times greater within an experimental station and more than four times greater between experimental stations than for digestibility. For DMI the variability associated with animals within a station was also the greatest source of variation in reproducibility. However, for this measure, the between-stations variability was greater than that found for digestibility. The repeatability and reproducibility obtained for the DOMI were similar to those obtained for the DMI (15.20 and 20.45 respectively for DMI and 10.81 and 13.76 for DOMI). Our results suggest that data obtained in different locations for the in vivo OMD using the same methodology, may be pooled without significantly decreasing the precision of the measurement. However, precision for the DMI might be adversely affected by pooling data obtained in different stations.

International audience; The effect of animal feeding on milk volatile organic compounds (VOCs) of metabolic origin was tested on a hay-based diet (H), a highly diversified pasture under continuous grazing (CG), or a less diversified pasture under rotational grazing (RG). Individual milk of 24 Montbeliarde cows (8 per treatment) were sampled after 2 weeks. Pasture-derived milk was richer (p < 0.05) in camphene, sabinene, beta-caryophyllene, and skatole than H milk. Neither milk yield nor fat content affected the majority of VOCs measured. Skatole increased slightly with milk yield, while indole and cineole decreased slightly with milk fat content but with poor regression (R(2) < 0.54). Multivariate analysis showed that, on the basis of those VOCs of metabolic origin whose concentration differed between treatment (dimethyl-sulfone, skatole, toluene, undecanoic acid, 1-octadecene, benzeneacetaldehyde, octanoic acid, and 2-pentanone-4-hydroxy-4-methyl), it was possible to obtain good discriminations among feeding systems. This study is promising for a future use of VOCs of metabolic origin to trace animal feeding systems.

In the mining district of Bou Azzer, garnierites containing variable proportions of Ni-kerolite and Ni-lizardite occur within a serpentinized ultramafic body of Precambrian-II age. These garnierites have high Ni-contents partially substituted by Co. Their oxygen isotope composition (δ 18 O = + 16.5‰) and the random distribution of Ni and Mg cations in the octahedral sheet of kerolites indicate a formation temperature higher than 25°C. These data and the occurrence of gamierites within veins, located along faults and associated with Ni-arsenate ores, show that these garnierites were formed during an early low-temperature hydrothermal event. This is the first record of such a garnierite occurrence since all the other ones, recent or ancient, are considered as lateritic weathering products of ultramafic rocks

International audience; We describe 6 cases of severe filamentous fungal infections after widespread tissue damage due to traumatic injury in previously healthy people. Additionally, we report 69 cases from an exhaustive 20-y review of the literature to investigate the epidemiological and clinical features, the prognosis and the therapeutic management of these post-traumatic severe filamentous fungal infections. Traffic (41%) and farm accidents (25%) were the main causes of injury, which involved either the limbs only (41%) or multiple sites (41%). Necrosis was the main symptom (60%) and Mucorales (72%) and Aspergillus (11%) were the 2 most frequent fungi causing infection. These infections required substantial surgical debridement or amputation (96%) associated with aggressive antifungal therapy (81%), depending on the responsible fungi. This study underlines the need for early, repeated and systematic mycological wound samples to guide and adapt surgical and antifungal management in these filamentous fungal infections.

Mesocestoides corti (syn. vogae), as many other cestode platyhelminthes, contains abundant mineralized structures called calcareous corpuscles. These concretions may constitute as much as 40% of the dry weight of the organisms, but their function remains poorly understood. In this work, we reviewed the mineral composition of the calcareous corpuscles of M. corti. X-ray diffraction pattern showed that the major mineral component of the corpuscles is a hydrated form of calcium carbonate, monohydrocalcite, also confirmed by infrared spectrometry. The baseline shift of the X-ray diffraction spectra suggested the presence of amorphous calcium carbonate, accordingly to previous reports, and an organic matrix was confirmed by FTIR. Monohydrocalcite is a rare mineral unusually found in biominerals. Although the significance of monohydrocalcite in biominerals has not been determined, the knowledge of corpuscles composition is of relevance to establish their function and for the elucidation of the mechanisms involved in mineralization processes.

Phenolics contribute to the micronutrient composition of forages, which in turn may affect animal product composition. To assess the importance of these compounds, the polyphenolic and botanical composition of a permanent mountain pasture in the Massif Central (France) were studied at three stages of growth. Phenolic fractions (acids, flavonoids and total) were analysed using HPLC and specific colorimetric methods over the whole pasture and in nine main species. On a botanical level, 43 species including 31 dicotyledons composed a mountain variant of Cynosurion grouping. Over time, the species growing on the field changed, the main plants being Festuca nigrescens and eight dicotyledons. In whole pasture, about 170 different compounds were separated by HPLC, of which only 30 were common to all stages. The total polyphenolic content was estimated as 31, 32 and 19 g kg−1 DM for the three stages. They were mainly composed of dihydroxycinnamic derivatives (3,5-di-O-caffeoylquinic, chlorogenic, 1,5-di-O-caffeoylquinic acids), and of flavonoids in lesser proportions. Some polyphenols were peculiar to a few species and others were ubiquitous. The two major dicaffeoylquinic acids were identified for the first time in Achillea millefolium and Knautia arvernensis. Colorimetric measurements of phenolic fractions were in good agreement with HPLC analysis (P < 0.01) for all species studied. Thus, on the mountain pasture studied, a cow would be expected to ingest up to 500 g of polyphenols daily, which could affect the quality of animal products. Copyright © 2007 Society of Chemical Industry

This paper analyses the consequences of repeated regrouping of dairy heifers according to their behaviour, stress physiology and production. Thirty-two Holstein heifers were housed in pairs. Between 11 and 13 months of age, half were subjected to 16 pen relocations each time with a new peer (regrouped heifers), while the other half remained in the same pen with the same peer (controls). The heifers were observed in standardised behavioural tests comprising sudden (opening of an umbrella), novel (an unfamiliar arena) or predator-related (dog) stimuli. All behavioural tests were conducted on three sessions between the 13th and the 16th regroupings. The functioning of the HPA axis was assessed through blockade by dexamethasone and stimulation by ACTH after the 14th regrouping and stimulation by CRF after the 15th regrouping. Weight gain was assessed during the regrouping period and reproduction (No. of inseminations before successful insemination) thereafter. Regrouped heifers reacted less than the controls to the umbrella ( = 8.23, P < 0.05). They started eating more quickly in the arena (F = 10.8, P < 0.01). In the presence of the dog, they were less active (F = 6.26, P < 0.05) and tended to look at the dog less often (F = 3.63, P < 0.10). The reduction in behavioural responses from one session to the next one was more pronounced in regrouped heifers (e.g. number of eating bouts: F (session treatment) = 4.23, P < 0.05). Regrouped heifers had lower cortisol responses to CRF. In conclusion, repeatedly regrouped heifers appear less disturbed by unusual situations and habituate to those more quickly. According to the behaviour of heifers and as suggested by their lower cortisol responses, diversity rather than stability of the social environment appears more beneficial to them., Cet article rapporte les conséquences de mélanges répétés d'animaux sur le comportement, le stress et la production de génisses de race laitière. Trente deux génisses Holstein ont été élevées par paires. Au sein de huit paires, les animaux ont changé de partenaires une à deux fois par semaine entre 11 et 13 mois d'âge, pour un total de 16 mélanges (génisses " mélangées "). Ces mélanges s'accompagnaient également de changements de parc. Les huit autres paires sont restées inchangées (génisses " témoins "). La réactivité comportementale a été mesurée en exposant les génisses à un événement soudain (ouverture d'un parapluie), à un environnement nouveau (alimentation dans un nouvel enclos) et à un prédateur (chien). Chaque test était répété trois fois, entre le 13 et le 16 mélange. Le fonctionnement de l'axe corticotrope a été évalué à l'aide d'un test de freination par la dexamethasone puis stimulation par l'ACTH après le 14 mélange et par un test de stimulation au CRF après le 15 mélange. Le gain de poids a été évalué par pesée hebdomadaire au cours des 16 mélanges. Par la suite, le nombre d'inséminations avant insémination fécondante a été relevé. Les génisses mélangées ont réagi à l'ouverture du parapluie moins fortement que les témoins ( = 8,23, P < 0,05). Elles ont commencé à manger plus rapidement dans l'enclos nouveau (F = 10,8, P < 0,01). En présence du chien, elles ont été moins actives (F = 6,26, P < 0,05) et tendaient à le regarder moins souvent (F = 3,63, P < 0,10). En outre, la diminution des réponses comportementales d'une séance sur l'autre était plus marquée chez les génisses mélangées (par exemple, nombre de prises alimentaires : F (séance traitement) = 4,23, P < 0,05). Par ailleurs, l'élévation du taux plasmatique de cortisol consécutive à l'injection de CRF a été moins prononcée chez les génisses mélangées. En conclusion, les génisses préalablement exposées à des réallotements répétés sont moins perturbées par des situations non familières et s'y habituent plus facilement par comparaison aux génisses maintenues avec le même partenaire. Dans ces conditions, il semblerait que ce soit la diversité de l'environnement social plutôt que sa stabilité qui ait permis d'améliorer la réactivité émotionnelle des génisses.

Carotenoids are involved in the sensorial and nutritional values of dairy products. In grazing systems, both herbage maturity stage and grazing management may affect the amount of carotenoid ingested, thus these factors may affect carotenoid concentrations in milk. Two homogenous plots of mountain grassland (1.4 and 2.0 ha) were grazed during two cycles of growth by 6 dairy cows in mid lactation, in strip (SG) and rotational grazing (RG), respectively. We monitored the changes in carotenoid concentrations in sward and milk, measured by HPLC twice a week. Seven carotenoids were identified in the sward: violaxanthin, antheraxanthin, epilutein, lutein, zeaxanthin, ß-carotene and 13-cis ß-carotene. Forage quality decreased throughout the course of the first growth stage, but carotenoid concentration in sward did not significantly change. In early regrowth, forage quality was high and the concentration of ß-carotene and xanthophylls also tended to be higher. Carotenoid concentrations in sward were not affected by grazing management, averaging 350 g per g DM. The carotenoids identified in milk were -carotene (75%) and lutein (25%). A significant decrease in ß-carotene concentration in milk was observed throughout the course of the first growth stage, from 5.37 to 3.87 g per g fat, whereas it increased to 4.91 g per g fat in early regrowth. -carotene concentration in milk was not affected by grazing management, averaging 4.72 and 5.03 g per g fat for RG and SG, respectively. However, lutein concentration was slightly lower for RG than for SG, averaging 1.39 and 1.74 g per g fat, respectively. It is concluded that carotenoids in milk were only slightly affected by herbage maturity stage, and to a lesser extent by grazing management., Les caroténoïdes sont impliqués dans les caractéristiques sensorielles et nutritionnelles des produits laitiers. Au pâturage, les teneurs en caroténoïdes du lait pourraient dépendre du stade de l'herbe et du mode de pâturage, qui conditionnent la quantité et la qualité de l'ingéré. Pour valider cette hypothèse, deux prairies naturelles de montagne homogènes, de 1,4 et 2,0 ha, ont été exploitées par 6 vaches en milieu de lactation, en pâturage tournant rapide (SG) et lent (RG), respectivement, pendant deux cycles de végétation. Nous avons suivi l'évolution des teneurs en caroténoides de l'herbe et du lait, déterminées par HPLC sur deux prélèvements par semaines. Dans l'herbe, sept caroténoïdes ont été identifiés: violaxanthine, anthéraxanthine, épilutéine, lutéine, zéaxanthine, ß-carotène et 13-cis ß-carotène. Au cours du premier cycle de végétation, la valeur nutritive de l'herbe a fortement diminué, mais sa teneur en caroténoïdes n'a pas été significativement modifiée. Les teneurs en ß-carotène et xanthophylles et la valeur nutritive de l'herbe étaient les plus élevées au début du deuxième cycle. La concentration en caroténoïdes de l'herbe n'a pas été affectée par le mode de pâturage, et était en moyenne de 350 g par g MS. Dans le lait, les caroténoïdes identifiés ont été le ß-carotène (75 %) et la lutéine (25 %). La concentration en ß-carotène dans le lait a diminué significativement de 5,37 à 3,87 g par g MG pendant le premier cycle de végétation, et était la plus élevée au début du deuxième cycle (4,91 g par g MG). La concentration en ß-carotène dans le lait n'a pas été affectée par le mode de pâturage, en moyenne 4,72 et 5,03 g par g MG pour RG et SG, respectivement. Cependant, la concentration en lutéine était légèrement plus faible avec RG (1,39 g par g MG) qu'avec SG (1,74 g par g MG). En conclusion, la concentration en caroténoïdes dans le lait a été légèrement affectée par le stade de l'herbe, et dans une moindre mesure par le mode de pâturage.

Deux lots de genisses Salers conduites en croissance continue (lot CG, n = 9 ) ou discontinue (DG, n = 14) ont ete compares pendant deux annees de croissance post-sevrage. Pendant toute l'experience, les animaux etaient alimentes a volonte. Les ecarts hivernaux de croissance etaient dus a la distribution de foins de qualite distincte. En ete, les genisses restaient a l'etable et recevaient un foin identique de bonne qualite. Les evolutions de la composition corporelle et des caracteristiques musculaires (type et surface des fibres, collagene) susceptibles d'influer sur la qualite de la viande, ont ete estimees apres des abattages en serie. Ce schema experimental a permis de simuler deux types de milieu nutritionnel (pauvre et riche) et d'en etudier l'impact sur l'ingestion, la croissance, la composition corporelle et les caracteristiques musculaires des animaux. Le lot DG a systematiquement realise une croissance compensatrice estivale, bien qu'incomplete, par rapport au lot CG. Du fait d'un abattage final a meme poids vif, environ 700 kg, les animaux DG ont ete abattus en moyenne 56 jours plus tard que les genisses CG. Les differences de gains de poids moyens valent toujours environ 300 g.j - 1 , en faveur respectivement de CG en hiver et de DG en ete. La compensation etait due a une ingestion accrue en ete (entre +6 et +7 %) et a une tendance pour une meilleure efficacite de la croissance des animaux DG. Aucune difference notable de composition corporelle n'a ete observee entre lots apres l'abattage final. Le poids des carcasses etait alors legerement inferieur a 400 kg et celui des tissus adipeux totaux atteignait environ 130 kg (21,5 % du poids vif vide). Le type de croissance n'a pas non plus influe sur les caracteristiques musculaires finales. En conclusion, l'itineraire de croissance de l'animal peut varier en fonction de la disponibilite alimentaire, sans modifier les caracteristiques des carcasses finies a poids constant.

Terpene profiles in cheese can be considered a ‘terroir’ fingerprint as the information contained in it should enable the pastures on which the animals were fed to be recognised. Yet a certain elasticity of the signature must be taken into account when determining authentication strategies, since products acknowledged as containing a common signature may have undergone certain procedures, such as cheese making and milk pasteurisation, that could have potentially altered their terpene profiles. In this study, Cantal and Saint-Nectaire-type cheeses were made from both raw and pasteurised milk from the same herd of dairy cows that had been grazed on natural grassland. Cheeses from raw and pasteurised milk were made from the same milking on the same days. Cantal and Saint-Nectaire-type cheeses were made on 4 different days, alternatively over four weeks. The terpenes in the cheese fat were analysed by dynamic headspace/gas chromatography/mass spectrometry. A great diversity of monoterpenes, sesquiterpenes and oxygen-containing derivatives were identified. The major terpenes identified in most cheeses were β-caryophyllene, α- and β-pinene and limonene. Milk pasteurisation did not induce changes in the terpene profile of the cheese. Significant differences (p < 0.001) were observed between Cantal and Saint-Nectaire cheeses: α-pinene, β-myrcene and β-phellandrene were, respectively, three, five and five times more abundant in Cantal cheese, while tricyclene, α-phellandrene and geraniol were found exclusively in Cantal cheese. In contrast, unidentified sesquiterpenes with retention indices (KI) = 1342 and 1511, α-cubebene, longifolene and γ-elemene were more abundant or exclusively found in Saint-Nectaire cheese. A significant relationship with the date of milking (p < 0.01) was observed for α-pinene and tricyclene in Cantal, for β-myrcene, δ-3-carene, p-cymene and α-terpinene in Saint-Nectaire cheese. Copyright © 2005 Society of Chemical Industry

Regrouping of cattle according to age, live weight or production stage is a common practice on farms. Our study aimed at determining how repeated regrouping modifies the social behaviour of dairy heifers, and more specifically if dominance relationships are formed more rapidly when animals become more familiar with regrouping. Thirty-two Holstein heifers were housed in pairs. From the age of 11 months, half of the heifers were placed in a new pen with a new penmate once or twice weekly for a total of 16 times over 11 weeks (regrouped heifers), while the other half remained in the same pen with the same penmate (controls). The heifers were monitored (a) for 3 h immediately after the 2nd, 7th, 13th and 16th regrouping, (b) for 24 h before the 1st regrouping, and after the 5th, 12th and 16th regrouping and (c) during a social confrontation test (with one animal for each treatment placed together in an arena) just before the 16th regrouping. Regrouping consistently induced agonistic interactions. Heifers exchanged the fewest agonistic interactions on the 7th regrouping and the greatest on the 16th. Dominance relationships were established most rapidly on the 7th regrouping (84 ± 20 min), but developed over the longest period on the 16th regrouping (158 ± 56 min). Observations for 24 h after the 16th regrouping showed that regrouped heifers moved and changed their activity more often than the controls. No treatment differences were observed in the social confrontation test. In conclusion, heifers do not habituate to regrouping and repeated regroupings have little effect on their subsequent social behaviour. An optimum of around seven regroupings appear to produce the fewest agonistic interactions and allow dominance relationships to be established more rapidly.

Twenty-eight multiparous dairy cows were divided into 2 groups: one group (S) was fed a ray-grass silage diet and the other one (H) a hay-based diet. The milk produced by these cows was used to make Saint-Nectaire-type cheese on one day and Cantal cheese on the following day, using identical, controlled cheesemaking techniques for each model. The S cheeses, regardless of the model, had higher fat (P < 0.01) and fat in dry matter (P < 0.05) contents but lower total nitrogen content (P < 0.001) and exhibited a more yellow tone. The differences in sensory characteristics were more pronounced in Cantal cheeses: H cheeses had more "butter" and "grass" odours, "citrus fruits" - "hay" -"hazelnut" aromas and more persistent flavour than S cheeses, which showed more "alcohol" odour, "chemical" aroma and had a less "melting", "mellow" texture. The dietary effect was greater with Cantal cheese because of a diet / cheese model interaction., Effet d'une alimentation à base d'herbe ou de foin sur les caractéristiques du fromage : interactions avec le modèle technologique. Vingt-huit vaches laitières ont été divisées en deux groupes : l'un (S) a reçu un régime à base d'ensilage de ray-grass et l'autre (H) à base de foin. Le lait de ces animaux a été transformé un jour en fromage de type Saint-Nectaire et un autre jour en fromage de Cantal, dans des conditions technologiques contrôlées et identiques d'une fabrication à l'autre pour chaque type de fromage. Quelque soit le modèle fromager, les fromages S ont eu des taux plus élevés de matière grasse (P < 0,01) et d'extrait sec (P < 0,05) mais une plus faible teneur en azote total (P < 0,001) et ils ont été plus jaunes. Les différences de caractéristiques sensorielles ont été plus marquées dans le cas du Cantal : les fromages H ont été caractérisés par des odeurs " beurre " et " herbe ", des arômes " agrumes ", " foin ", " noisette ", et une flaveur plus persistante que les fromages S, qui ont révélé une odeur d'" alcool ", un arôme " chimique " et une texture moins " fondante " et " moelleuse ". L'effet régime alimentaire a été plus marqué dans le cas du fromage de Cantal révélant une interaction entre l'alimentation des animaux et le modèle fromager.

The effect of mastitis and related-germs on milk chemical composition (protein and lac- tose contents) and milk somatic cell count (SCC) was investigated in 501 milk quarter samples during two consecutive years in cows from three experimental herds. Each infected quarter was matched by a healthy one in the same udder, as a control. Milk protein and mineral assays were performed in a sub- sample of 128 milks. Staphylococci were the most frequently isolated germs (Staphylococcus aureus: 27%, coagulase-negative Staphylococci: 26%, Streptococci: 21%). Major milk pathogens (Staphylococcus aureus, Streptococcus uberis or Escherichia coli) associated with clinical signs of mastitis were accompanied by higher SCC (+1.6 log·mL -1 , P < 0.01), lower lactose concentration (-7.6 g·kg -1 , P < 0.01), higher protein concentration (+3.3 g·kg -1 , P < 0.01) and higher soluble protein concentrations (IgG and BSA), hence a sharp decrease in the casein/protein ratio (-10 percentage points, P < 0.01). Changes were more marked when Escherichia coli was present. Corynebacterium bovis did not alter milk chemical composition whereas coagulase-negative Staphylococci slightly re- duced lactose concentration (-1.8 g·kg -1 ) and increased SCC (+0.37 log·mL -1 ). Calcium and phos- phorus milk contents were hardly modified by the presence of microorganisms. The decrease in milk yield during clinical mastitis varied from 1.6 kg·d -1 in the presence of Staphylococcus aureus to 15 kg·d -1 in the presence of Escherichia coli.

After a milk meal, bucket-fed calves show non-nutritive oral activities, including cross-sucking, and this can discourage producers from rearing them in groups. Sucking is known to induce a quiet state in humans and rats. We examined if nutritive sucking affects non-nutritive oral activities in calves, if it reduces arousal (assessed through behavior and cardiac activity), and if sucking a dry teat can compensate for the lack of nutritive sucking. In Exp. 1, the behavior and the cardiac activity of individually housed calves fed milk from a bucket were compared to those of calves fed milk through a teat. During the meal, the heart rate of bucket-fed calves was higher than that of teat-fed calves (P < 0.0001). After the meal, only bucket-fed calves displayed bar sucking. Compared to the teat-fed calves, they spent more time licking their pen or their neighbor (P < 0.001 and P < 0.05), their heart rate was less variable (P < 0.01), and they lay down with the head unsupported by the neck less quickly (latency to lie down: 51 min vs 42 min, P < 0.05). In Exp. 2, individually-housed bucket-fed and teat-fed calves were observed with or without access to a non-nutritive teat after the meal. Bucket-fed calves sucked the dry teat for longer than teat-fed calves (P < 0.001). In bucket-fed calves, access to the dry teat reduced the time spent nibbling (P < 0.01) and tended to shorten the latency to lie down (P < 0.10). In Exp. 3, group-housed bucket-fed calves were compared with group-housed calves fed with an automatic teat feeder system. Bucket-fed calves spent more time nibbling at 1 mo, but at 3 mo they spent less time nibbling and cross-sucking; they drank more milk and put on more weight. We conclude that, for calves housed individually, teat-feeding reduces non-nutritive oral activities after the meal and induces a calmer state than bucket-feeding. Providing calves with a dry teat partly compensates for the lack of nutritive sucking. For calves housed in groups, the use of an automatic teat feeder may not reduce calves' motivation for sucking. No improvement of growth was observed with teat-feeding either with a teat-bucket or with an automatic feeder.

Because of welfare concerns and increased labor efficiency, calves are increasingly housed in groups. To reduce variability in live weight within groups, farmers frequently regroup calves according to growth rate. We assessed the consequences of repeated regrouping and relocation on the welfare of 32 male Holstein calves housed in pairs. Animals of half of the pairs (regrouped calves) were placed in a new pen with a new partner once a week for 14 wk. Animals of the other half of the pairs (control calves) stayed in the same pen with the same partner. Behavior was observed for the 3 h following four mixings and for 24 h after all relocations were finished. The functioning of the hypothalamic-pituitary-adrenal axis and of the sympathetic nervous system were assessed. Calves were weighed once a week, their health was assessed daily, and abomasa were inspected when the calves were slaughtered. Calves reacted to the first mixing by interacting with the new partner and increasing their general activity (sniffing the partner in regrouped calves vs controls: 5.5 vs 2.9, P < 0.01; percentage time stepping: 3.2 vs 1.3, P < 0.001). This effect disappeared by the ninth mixing. After all relocations were completed, regrouped calves were more active at the end of the day and less active at night (P < 0.05). Cortisol responses to exogenous ACTH were higher in regrouped calves (integrated response: 6,688 vs 5,508 ng x min/mL, P < 0.01). Basal cortisol levels, ACTH responses to corticotropin-releasing hormone, activities of catecholamine-synthesizing enzymes (tyrosine hydroxylase and phenylethanolamine N-methyl transferase), and the incidence of health problems and growth rates did not differ between the two groups. Regrouped calves had fewer abomasal ulcers. Apart from the increased sensitivity of the adrenal cortex of regrouped calves to ACTH and the modification in the daily rhythm of activity, there was no clear evidence that repeated regrouping and relocation stresses calves. Aggression between calves was rare, and calves seemed to habituate to repeated mixing.

Two groups of 15 multiparous cows in mid-lactation were used in a Latin square design experiment with 4-week experimental periods. The genetic milk protein concentration level was high in the first group and low in the second. Each group of cows was given in a random order three feeding levels that covered 85, 100 and 115% of energy requirements and 90, 110 and 125% of nitrogen requirements, respectively. In both groups, increasing level of feeding induced a significant increase in milk yield (+2·4 kg/d between lowest and highest levels) and in protein concentration (+1·7 g/kg). The proportion of paracasein in total proteins was not altered by either genetics or nutrition. The proportion of casein in total proteins was slightly increased by 0·5 percentage points (PPn = 90), the relationships between casein or paracasein and total protein concentrations were linear and very narrow (R2 = 0·92 and 0·95, respectively). The proportion of casein or paracasein in total proteins significantly decreased as plasmin activity increased.

The composition and sensory characteristics of matured cheeses are controlled by a number of factors, among which the type of feed is important. The influence of feeding can be reflected by the presence in cheeses of terpenes and sesquiterpenes, compounds typically indicating their vegetable origin (Mariaca et al. 1997). Indeed, several investigators have already established that these compounds could characterize the forage even to a specific geographical location. Dumont & Adda (1978), Dumont et al. (1981), Guichard et al. (1987), Bosset et al. (1994) and Moio et al. (1996) were thus able to distinguish cheeses from lowland and upland regions. In most of these studies, the conditions under which milk was produced and processed were not completely controlled. Furthermore, all these studies analysed only the volatile fraction of cheeses and did not examine the volatile compounds in the forages used. Recently Bosset et al. (1994), in one part of the project described by Jeangros et al. (1997), showed that highland grass with a highly diversified botanical composition produces milk and cheeses with significantly different chemical compositions from those from lowland grass. To improve our understanding of the relationship between animal feed and cheese composition, we have investigated under controlled experimental conditions both the composition of the terpene and sesquiterpene fractions of four forages with different botanical diversities and the influence of those forages on the terpene fraction of cheeses.

Two groups of eight multiparous cows with different calving periods (November or February) were managed in the same way during lactation. During four 4 week experimental periods distributed over 12 months, the cows were fed on a diet composed of hay and concentrate (70[ratio ]30) in a restricted and controlled amount which varied according to their lactation stage, so as to cover the animals' requirements correctly. The animals' average lactation stage varied according to period from 26 to 298 d. Milk from each group was processed on two occasions during each period to make Saint-Nectaire-type cheese; the cheesemaking conditions were the same throughout. Lactation stage had an important effect on milk fat, protein and calcium contents but not on the casein[ratio ]protein ratio or phosphorus content. The milk pH and the urea content were higher in late lactation. The calcium concentration of milk was higher in late lactation but the soluble fraction was higher in early lactation. Despite higher protein contents, the maximal firmness of the coagulum of late-lactation milk was not different from that of early or mid-lactation milks. pH was higher in cheeses from late-lactation milks compared with those from early and mid-lactation milks. Cheeses from early lactation milks were more yellow than the others and had a lower dry matter fat content. In sensory analysis the odour of cheeses from early and late-lactation milks was less pleasant than that of those from mid-lactation milks. Cheeses from late-lactation milks were more melting and less firm than those from early or mid-lactation milks. Their taste was more intense and more persistent. At tasting, they were less appreciated than the others. These differences were linked to increased proteolysis in the cheeses made with late-lactation milks.

Forty-two multiparous dairy cows of three different breeds (Holstein, Montbéliarde and Tarentaise) were fed on the same type of forage (natural grassland) preserved in the form of either hay (H) or silage (GS), according to a changeover design (two 4 week periods). The proportion of concentrate in the diet and the energy and nitrogen contents were similar in both treatments. The milk produced by these cows was used for the manufacture of Saint-Nectaire type cheeses, under controlled and identical cheesemaking technological conditions. More cheese was produced with the H treatment milk. The cheeses made with the GS treatment milk were more yellow and tended to be more bitter. The other chemical and sensory characteristics did not differ much between the two treatments. Of the 51 volatile compounds identified, four were in significantly higher proportion in the GS than in the H cheeses. Cheeses produced from Tarentaise cows' milk were more yellow and their pH was higher than those made with the milk of Holstein or Montbéliarde cows. The cheeses from Montbéliarde and Tarentaise cows' milk were firmer, more melting and tastier than those made with the milk of Holstein cows. Although some trends were apparent, there were no significant differences in cheese volatile compounds for different breeds.

The aim of this work was to assess the role of social and physical enrichment in the adaptation of veal calves to their environment. We compared calves housed in individual stalls that varied in the extent of contacts they allowed between neighbors (16 calves: open partitions; 16 calves: solid partitions; 32 calves: solid and extended partitions preventing all contact). All but 16 out of the 32 isolated calves were provided with a piece of tire and a chain, objects they could easily nibble. We assessed time budget, behavioral reactions to a water throw, neuroendocrine responses to stress (ACTH challenge and catecholamine synthesis), health, and growth. Calves kept in isolation displayed more startled reactions (16 isolated calves vs 5 non-isolated calves were startled by the throw, P

Quarante-deux vaches laitieres multipares en milieu de lactation ont ete utilisees dans un essai en inversion. Pendant chacune des deux periodes de 4 semaines, les animaux ont recu une ration de fourrage isoenergetique, a base d'ensilage d'herbe (12 kg de matiere seche/jour) ou de foin (12,5 kg de matiere seche/jour). Ces deux fourrages avaient ete recoltes le meme jour sur la meme parcelle de prairie naturelle. Chaque ration a ete complementee avec la meme quantite d'un melange d'orge et de tourteau de soja dont les proportions ont ete calculees de maniere a ce que les apports azotes soient voisins et non limitants dans les deux traitements. Les vaches recevant de l'ensilage d'herbe ont produit 0,7 kg/jour (p < 0,05) de lait de plus que celles recevant du foin, mais leur lait a ete significativement plus pauvre en matieres grasses (-1,2 g/kg), en proteines (-1,0 g/kg) et en caseines. Les bilans energetiques et les variations de poids vif ayant ete voisins dans les deux lots, ces resultats sont essentiellement dus a un effet de dilution des matieres utiles secretees. Le rapport caseines/proteines et la teneur en proteines solubles du lait n'ont pas ete significativement differents selon le type de ration de base. La teneur en calcium du lait a ete significativement plus faible, et celle en phosphore plus elevee, avec la ration a base de foin.

parous dairy cows in mid-lactation were used in an experiment with a 2x 2 Latin-square design. During each 3-week period, the cows were offered a diet composed of native mountain grassland given as hay (first eut) or grazed (second eut of the same plot). The milk yielded by these cows was used in the manufacture of Saint-Nectaire cheeses, under controlled technology manufacturing conditions which were identical from one production ta another. Milk yield was higher at pasture (+ 1.8 kg/day, P < 0.01). Urea content was higher with hay (+ 5.6 mg/100 mL, P < 0.01), and calcium content was slightly lower (-0.05 g/kg, P < 0.05). Other chemical contents (fat, protein, casein), pH and renneting properties of milk were similar in bath treatments, as most of the chemical (dry matter, fat in dry matter, pH) and sensory characteristics (taste, odour, colour) of the cheeses. However, cheeses were firmer and more acid when forage was given as hay.

Des vaches laitieres de 3 types genetiques differents (Holstein, Montbeliarde et Tarentaise) ont recu, selon un dispositif experimental en carre latin 3 x 3, 3 natures de fourrage differentes (ensilage de ray-grass anglais, foin de seconde coupe de dactyle et ensilage de mais). La part de concentre dans la ration, et le niveau des apports energetiques et azotes ont ete semblables dans les 3 traitements alimentaires. Le lait de ces vaches a ete transforme en fromages de Saint-Nectaire, dans des conditions technologiques de fabrications controlees et identiques d'une fabrication a l'autre. Les fromages realises avec du lait d'ensilage d'herbe presentent une pâte plus jaune que celle des fromages realises avec du lait de foin de seconde coupe ou d'ensilage de mais. Les fromages au lait de foin de seconde coupe se differencient des autres par leur caractere collant et leur moindre fermete ; ils obtiennent une note globale superieure de 0,6 a 1 point (P < 0,05) a celles des autres types de fromages. Les fromages realises a partir du lait de vaches Montbeliardes et Tarentaises ont ete mieux notes que ceux realises a partir du lait de vaches Holstein. Les differentes origines de ces ecarts sont discutees en relation avec la composition chimique des aliments.

National audience

We studied theimportance of the stock-person’s behavior on veal calf behavior using 22 vealcalves housed in individual crates. Eleven calves re-ceived minimal contact from the stockperson, and theother 11 calves were stroked and allowed to suck thestockperson’s fingers after each meal during the entirefattening period (21 wk). The effects of this additionalcontact with the stockperson on the calves’ responsesto people was studied, when in their home environment(crate) or outside their home environment (singly in anovel arena). When tested in their home environment,the calves receiving additional contact withdrew lessfrom the approach of humans (familiar or unfamiliar)Key Words: Behavior, Calves, Fearfulness, Handling, Veal 2000 American Society of Animal Science. All rights reserved. J. Anim. Sci. 2000. 78:1213–1218 Introduction In veal calf production, animals receive little contactwith people, and this contact is largely restricted tothe period around feeding. The development of moreautomated farming systems and increased number ofanimalsperstockpersonwillthusdecreasetheopportu-nities to develop positive associations between thestockperson and animals (Jago et al., 1999). In the vealcalf industry, this might have detrimental effects onthe ease of handling, welfare, and productivity of theanimals, as reported in the pig and poultry industries