Effect of forage:concentrate ratio on the quality of ewe's milk, especially on milk fat globules characteristics and fatty acids composition

2010 ◽  
Vol 77 (2) ◽  
pp. 239-244 ◽  
Author(s):  
Mina Martini ◽  
Gian Battista Liponi ◽  
Federica Salari

The aim of this study was to evaluate the milk quality of Massese ewes receiving diets with different forage:concentrate ratios (FC ratio), specially on milk fat globules characteristics and fatty acids composition. The diet is one of the main environmental factors that influence the lipidic content of milk. A trial was carried out on twenty ewes, which had been subdivided into two homogeneous groups and kept indoors at 25 days post partum. The experiment lasted 60 days, from 40 to 100 days post partum and the animals were fed two diets that differed in terms of the FC ratio: 60:40 and 40:60, as fed. The results obtained in this study showed that a greater proportion of forage, compared with an higher percentage of concentrate, led to an increase in the percentage of fat (+8·66%) and to a decrease in the percentage of milk fat globules with a size between 2 and 5 μm (−17·32%). However, the average diameter was not affected. There was also a decrease in the percentages of some medium chain fatty acids (C12:0, C14:0; −14·89% and −4·03 respectively) and an increase in mono and polyunsaturated ones such as trans11-C18:1 (+31·71%), total CLA (+22%), EPA (+18·18%) and DHA (+66·67%). In conclusion, a greater proportion of forage seem to improve the milk fatty acid profile by the increase of some fatty acid identified has being beneficial for human health.

2005 ◽  
Vol 72 (4) ◽  
pp. 476-481 ◽  
Author(s):  
Lars Wiking ◽  
Hanne C Bertram ◽  
Lennart Björck ◽  
Jacob H Nielsen

Cooling strategies for pumping of raw milk were evaluated. Milk was pumped for 450 s at 31 °C, or pumped after cooling to 4 °C and subsequently subjected to various incubation times. Two types of milk were used; i.e. milk from cows fed a diet high in saturated fat supplements resulting in significantly larger milk fat globules than the other type of milk which comes from cows fed a low-fat diet that stimulates high de novo fat synthesis. The content of liquid fat was determined by low-field 1H NMR, which showed that milk from cows given the saturated fat diet also contained less liquid fat at both 4 ° and 31 °C than the other type of milk. This can be ascribed to the differences in the fatty acid composition of the milk as a result of the fatty acid composition of the diets. After pumping of the milk at 31 °C, measurement of fat globule size distribution revealed a significant coalescence of milk fat globules in the milk obtained from the saturated fat diet due to pumping. Pumping at 4 °C or pumping the other type of milk did not result in coalescence of milk fat globules. Formation of free fatty acids increased significantly in both types of milk by pumping at 31 °C. Cooling the milk to 4 °C immediately before pumping inhibited an increased content of free fatty acids. However, when the milk was incubated at 4 °C for 60 min after cooling and then subjected to pumping, a significant increase in the formation of free fatty acids was observed in both types of milk. It is suggested that this increase in free fatty acids is caused by transition of polymorphic crystal forms or higher level of attached lipoprotein lipases to the milk fat globule before pumping.


2014 ◽  
Vol 81 (4) ◽  
pp. 485-493 ◽  
Author(s):  
Donato Casamassima ◽  
Maria Nardoia ◽  
Marisa Palazzo ◽  
Francesco Vizzarri ◽  
Angela Gabriella D‘Alessandro ◽  
...  

Milk yield and milk qualitative parameters were evaluated in Lacaune ewes on a diet supplemented with extruded linseed, verbascoside and vitamin E. A 98 d-trial was conducted on 44 ewes and started 40±2 d post partum. The animals were divided into four homogeneous groups of eleven animals each; one control group (CON) without extruded linseed and dietary supplements, and the diet of the other three experimental groups was enhanced with extruded linseed (L group), extruded linseed-verbascoside (LVB group), and extruded linseed-verbascoside-vitamin E (LVBE group). All animals individually received an isoenergetic diet, consisting of 700 g concentrated feed and meadow hay ad libitum. Body weight, body condition score, milk yield and milk qualitative parameters were assessed. LVB and LVBE groups resulted in a significant improvement (P<0·05) in milk yield due to the verbascoside supplementation. The extruded linseed supplementation L, LVB and LVBE groups produced a milk fat increase and a better milk fatty acid profile in terms of a higher monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA) and conjugated linoleic acid (CLA) content and a reduced saturated fatty acid (SFA) content, a lower n-6/n-3 ratio and atherogenic and thrombogenic index. The dietary verbascoside supplementation in the LVB and LVBE group resulted in a better milk quality due to the low cholesterol level and higher vitamin A and E contents, in addition to an increased oxidative stability highlighted by the lower thiobarbituric acid reactive substances (TBARS) level. Thus, the addition of extruded linseed and verbascoside supplements improved milk yield and quality both from a chemical and nutritive point of view.


2018 ◽  
Vol 69 (1) ◽  
pp. 160-165 ◽  
Author(s):  
Daniel Mierlita ◽  
Ioan Mircea Pop ◽  
Florin Lup ◽  
Daniel Simeanu ◽  
Simona Ioana Vicas ◽  
...  

This research was conducted to study fatty acids composition, especially content of n-3 FA; c9,t11-CLA (rumenic acid) and t11-C18:1 (vaccenic acid) and health lipid indices of milk according to the feeding practices in sheep. The exeperimental diets consisted of: P - pasture without any diet supplementation, PC - pasture + standard concentrate (500 g/d), PCs - pasture + fat-enriched concentrate (camelina seed-based concentrate: 500 g/d). Camelina seeds (Cs - Camelina sativa L) were used to increase the beneficial FA concentration in milk fat. PC diet as compared to P diet increases daily milk yield and the content of milk fat, but it adversely affects the quality of milk fats. Fat in the milk of PC ewes had a higher content of hypercholesterolemic FA, while the polyunsaturated FA (PUFA) concentration decreased (p [ 0.001). The use Cs in the concentrate mixture (PCs diet) increased by more than double the c9,t11-CLA, C20:5n-3 (EPA), C22:6n-3 (DHA), C18:3n-3 (ALA) and t11-C18:1 (VA) (p [ 0.001) in milk fat, without any negative effects on milk yield and composition. Beneficial changes of health lipid indices milk fat (atherogenic index, thrombogenic index, n-6/n-3 FA) were detected when the diet of ewes was supplemented with fat-enriched concentrate (PCs group) because of high concentration of c9,t11-CLA, n-3 FA which has sanogenic properties. It is concluded that, when pasture quality and availability do not limit dairy production, supplementation of grazing ewes with concentrate mixture is not recommended, because compromised the milk FA profile. The using camelina seeds in strategies for supplementing the diet of ewes on pastures is a good choice both for the daily milk yield and even more so for the sanogenetic quality of milk fats.


2003 ◽  
Vol 105 (11) ◽  
pp. 677-682 ◽  
Author(s):  
Valérie Briard ◽  
Nadine Leconte ◽  
Françoise Michel ◽  
Marie-Caroline Michalski

2009 ◽  
Vol 390 (1) ◽  
Author(s):  
Fernando Sánchez-Juanes ◽  
Josefa M. Alonso ◽  
Lorena Zancada ◽  
Pablo Hueso

AbstractSeveral components of milk fat globule membranes (MFGMs) have been reported to display beneficial health properties and some of them have been implicated in the defense of newborns against pathogens. These observations prompted us to determine the glycosphingolipid content of MFGMs and their interaction with pathogens. A comparative study with whole milk components was also carried out. Milk fat globules and MFGMs were isolated from milk. Gangliosides and neutral glycosphingolipids were obtained from MFGMs and whole milk and their fatty acid contents were determined by gas chromatography-mass spectrometry (GC-MS). MFGMs and whole milk showed similar ganglioside and neutral glycosphingolipid contents, with whole milk having more GM3 and glucosylceramide and less GD3,O-acetyl GD3,O-acetyl GT3, and lactosylceramide. The fatty acid content of gangliosides from both sources showed a similar composition. However, the neutral glycosphingolipid fatty acid content seemed to be quite different. Whole milk had fewer very-long-chain fatty acids (18.1% vs. 46.4% in MFGMs) and more medium-chain and unsaturated C18:1 and C18:2 fatty acids. Milk fat globules, MFGMs, lactosylceramide, and gangliosides GM3 and GD3 were observed to bind enterotoxigenicEscherichia colistrains. Furthermore, bacterial hemagglutination was inhibited by MFGMs and glycosphingolipids.


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