Effect of Grazing on the Fatty Acid Composition of Goat´s Milk or Cheese

Abstract

The objective of this study was to compare the fatty acid profile of caprine milk or cheese from animals raised under extensive, semi-extensive or full confinement production system in México. Feeding systems particularly grazing have been shown to affect essential fatty acid profiles, particularly the ω6/ω3 balance. Utilization of concentrates probably raises the omega 6 contents, or decreases omega 3 concentration, often exceeding 4:1 ω6/ω3 ratio, diminishing beneficial effects of ω3 regarding consumer health. The present study was conducted for two years (2016 and 2017) on 5,079 lactating goats from the states of Querétaro, Guanajuato, Colima, San Luis Potosí and Michoacán in México. Average milk production was 1.5/d liters (DS ± 0.9). Of the 98 farms studied, 35% were in full confinement, feeding basically alfalfa hay and concentrate (18% CP), 22% grazed rye grass, 17% pastured alfalfa (45% of these grazing systems were supplemented), finally 26% grazed were in silvopastoral surroundings, mainly without supplement. The use of concentrate in more than 35% of total feed consumption had an effect on the profile of essential fatty acids exceeding ω6/ω3 4/1 ratio. In 36 of the studied farms levels of ω6/ω3 exceeded 4:1, all of them were supplemented with 700 g /d or more concentrate. In those units the use of the supplement decreased ω3 or increased ω6.

Considerations on goat milk biochemical composition

“…By reducing this ratio, the inflammatory reaction of the body decreases and the risk of chronic diseases is reduced. The recommended optimum ratio is less than 5, but in animal products this ratio is different, between 10 and 15 [19,20]. Our data indicate that Carpathian females, whose food comes mostly from grazing, produce milk with a ratio below 4 during the summer.…”

Effect of Feeding Systems on Bovine Milk Quality in Mexico

“…Similarly, in the present study, the highest content of linoleic acid was in milk from FC while that of linolenic acid in milk from EG. Decreasing milk ω6/ω3 ratio showed several beneficial effects for human health [5,15], particularly with values lower than 4, since higher levels could modify the beneficial effects of ω3 [14,15]. In present trial, the relationship between breeding system and milk ω6/ω3 ratio was shown feeding animals with higher quantity of concentrates increased milk yield and ω6/ω3 ratio.…”

“…In recent years, the consumers' demand for foods with high nutritional value has strongly increased [1]. Concerning those of animal origin, it is accepted that animal diet can affect their quality [2][3][4][5]; in particular, foods produced by grazing ruminants are recognized by nearly all consumers, and farmers themselves, as high-quality foods [6]. On the other hand, dairy specialization and intensive farming have brought about an increase in the use of concentrates, thus reducing or even eliminating pasture as a feed source in many countries [7].…”

Fatty Acids of Semi-Hard Cheese Made from Milk of Goats Fed Diets Enriched with Extruded Linseed or Pumpkin Seed Cake

“…Pasture feeding and fat supplementation in diets have been proven to be a good dietary strategy in small ruminants’ feeding, in order to increase beneficial FAs, among them CLA, vaccenic acid (C18:1 t11), and ALA, which have been shown to possess nutritional properties that reduce cardiovascular risk in humans [ 33 , 34 ]. The inclusion of ELS and PSC in diet caused an increase in the proportion of C18:0 in cheeses, which increased from 11.8 in the control to an average 14.7 in ELS and 13.5 g/100 g FAME in PSC.…”