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Effects of new n-3 fatty acid sources on milk fatty acid profile and milk fat properties in dairy cows.
- Source :
-
The Journal of dairy research [J Dairy Res] 2018 Aug; Vol. 85 (3), pp. 265-272. Date of Electronic Publication: 2018 Jun 26. - Publication Year :
- 2018
-
Abstract
- Feeding livestock with n-3 fatty acid (FA) sources (linseed, for example) is a common strategy to improve lipid quality of meat and milk products. However, in monogastric animals, linseed tegument decreases digestibility and alphalinolenic acid (ALA) uptake, while the whole linseed is well used by ruminants. In a context of increasing sustainability of feeding systems, providing monogastric animals and ruminants with linseed products adapted to their digestive systems is an important issue. This research paper addresses the hypotheses: (i) sieved extruded linseed (SEL) specific for ruminants is as or more effective than standard extruded linseed (ii) microalgae DHA Gold® is an interesting source of docosahexaenoic acid (DHA) in feedstuff and (iii) the effects of SEL and microalgae on milk characteristics are complementary and additive. Thirty-two cows were divided into 4 groups with different dietary n-3 fatty acid sources using a continuous design. All the diets were fed as mixed rations based on maize silage, energy concentrate and soybean meal. The first group received a control diet (CTRL) with no additional fat. The 3 other groups received SEL, microalgae DHA Gold® (ALG) and a mixture of microalgae DHA Gold® and SEL (SEL/ALG). Milk was collected from morning milkings after six weeks of dietary treatment. In SEL and SEL/ALG, ALA increased (+0·32 and +0·26% unit, respectively), and DHA increased in ALG and SEL/ALG (+0·43 and +0·15% unit, respectively) compared to CTRL, as a consequence of the initial composition of the n-3 FA sources. In SEL, milk yield, fat and protein contents, milk fat globule size and spontaneous lipolysis (measured to evaluate suitability for milk processing) were not different compared with CTRL. In ALG and SEL/ALG, milk yield decreased (-2·8 and -6·0 kg/d, respectively), fat content was halved, and fat globule size was reduced (-1·46 and -1·31 µm, respectively) compared to CTRL. Spontaneous lipolysis increased in ALG (+0·12 mEq/kg of milk) compared to CTRL. Protected microalgae and the doses of microalgae in the diet need further investigation to prevent FA modification in the rumen and the consequent deleterious effects on milk fat.
- Subjects :
- Animals
Dairying
Diet veterinary
Digestion
Docosahexaenoic Acids administration & dosage
Female
Flax chemistry
Glycolipids
Glycoproteins ultrastructure
Lipid Droplets
Lipolysis
Microalgae chemistry
Milk Proteins analysis
Silage
Glycine max
Zea mays
Animal Feed analysis
Cattle metabolism
Fats analysis
Fatty Acids analysis
Fatty Acids, Omega-3 administration & dosage
Milk chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1469-7629
- Volume :
- 85
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- The Journal of dairy research
- Publication Type :
- Academic Journal
- Accession number :
- 29941054
- Full Text :
- https://doi.org/10.1017/S0022029918000390