فهرست مقالات lipid feed supplements

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  1 - Effect of Dietary and Animal Factors on Milk Fatty Acids Composition of Grazing Dairy Cows: A Review
  A.I. Roca Fernandez A. Gonzalez Rodriguez
  In pasture-based milk production systems, using available farm resources in order to reduce feeding costs, the composition and functional properties of dairy cows’ milk are of considerable importance to the dairy farmer, manufacturer and consumer. Basically, there چکیده کامل

  In pasture-based milk production systems, using available farm resources in order to reduce feeding costs, the composition and functional properties of dairy cows’ milk are of considerable importance to the dairy farmer, manufacturer and consumer. Basically, there are three options for altering the composition and/or functional properties of milk: 1) cow nutrition and grazing management, 2) cow genetics and 3) dairy manufacturing technologies. At the farm levels, manipulation of milk composition only occurs when it is perceived to be more profitable, normally, processing options are the option most considered. Nevertheless, opportunities exist for manipulation of milk composition on the farm to improve the human and physiological properties of milk and dairy products, such as enhanced concentrations of conjugated linoleic acid (CLA), or to improve its milk fatty acids (FA) composition for more efficient processing into a range of dairy products. This review considers the effect of dietary (pasture feeding, lipid feed supplements, seasonal and regional variations) and animal (breed, stage of lactation, parity and animal to animal) factors on milk FA composition of grazing dairy cows. Furthermore, it highlights the relevance that these factors, in the context of an integrative-view, might play on the sustainability of pasture-based milk production systems in humid areas in terms of milk differentiation and higher added value which profit would be directly reached for the milk producer on the farm. پرونده مقاله
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  2 - Effects of Concentrate Source (Cottonseed vs. Barley)on Milk Performance and Fatty Acids Profile of Holstein-Friesian Dairy Cows
  A.I. Roca-Fernandez A. Gonzalez-Rodriguez O.P. Vazquez-Yanez J.A. Fernandez-Casado
  Milk performance (protein and fat content) and milk fatty acids (FA) profile of dairy cows under supplementation with two sources of concentrate, oilseeds (C, cottonseed) at two levels, low (5kg DM/cow/day) and high (7 kg DM/cow/day), and cereal grains (B, barley) at hi چکیده کامل

  Milk performance (protein and fat content) and milk fatty acids (FA) profile of dairy cows under supplementation with two sources of concentrate, oilseeds (C, cottonseed) at two levels, low (5kg DM/cow/day) and high (7 kg DM/cow/day), and cereal grains (B, barley) at high rate (7 kg DM/cow/day), were studied in three herds (n=36) of spring calving Holstein-Friesian dairy cows (200 days in milk). Animals were randomly assigned to one of three indoors (n=12) silage feeding regimes (C5, C7 and B7), using a TMR (total mixed ration) basal diet, containing 70-80% silage (grass: maize, 36: 64) and 30-20% concentrate. Daily milk yield (MY) was higher (P<0.001) at high level of supplementation (B7, 18.1andC7, 17.9 kg/cow/day, respectively) compared to low level (C5, 15.7 kg/cow/day), and dairy cows at the highest level of concentrate showed the highest (P<0.05) body weight (B7, 605 and C7, 598, respectively). Milk protein content was lower (P<0.05) in the high level of cottonseed (C7, 30.7 g/kg DM) than in the barley treatment (B7, 32.7 g/kg DM). There were no differences among treatments in milk fat and milk urea content.Weekly milk FA profile of cow milk was determined using gas chromatography-mass spectrometry,during seventy days in autumn, and no differences were found among treatments in short, medium and long chain FA. Despite this, higher (P<0.05) contents of polyunsaturated fatty acids (PUFA) and linoleic acid were found in the C7 treatment compared to the C5 treatment (2.48 and 2.22 vs. 2.16 and 1.92 g/100 g of FA methyl esters, respectively). Including the high levels of cottonseed and barley as a concentrate source for feeding dairy cattle revealed similar MY and milk fat content. However, the high level of cottonseed in the diet of dairy cows showed decreased milk protein content and increased linoleic acid and PUFA levels. پرونده مقاله