Effects of increased supplementation of n-3 fatty acids to transition dairy cows on performance and fatty acid profile in plasma, adipose tissue, and milk fat

Abstract

The objective of this study was to determine the effects of feeding an increased amount of extruded flaxseed with high proportions of n-3 fatty acids (FA) to transition dairy cows on performance, energy balance, and FA composition in plasma, adipose tissue, and milk fat. Multiparous Israeli-Holstein dry cows (n = 44) at 256 d of pregnancy were assigned to 2 treatments: (1) control cows were fed prepartum a dry-cow diet and postpartum a lactating-cow diet that consisted of 5.8% ether extracts; and (2) extruded flaxseed (EF) cows were supplemented prepartum with 1 kg of extruded flaxseed (7.9% dry matter)/cow per d, and postpartum were fed a diet containing 9.2% of the same supplement. The EF supplement was fed until 100 d in milk. On average, each pre- and postpartum EF cow consumed 160.9 and 376.2g of C18:3n-3/d, respectively. Postpartum dry matter intake was 3.8% higher in the EF cows. Milk production was 6.4% higher and fat content was 0.4% U lower in the EF group than in the controls, with no differences in fat and protein yields. Energy balance in the EF cows was more positive than in the controls; however, no differences were observed in concentrations of nonesterified fatty acids and glucose in plasma. Compared with controls, EF cows had greater proportions of C18:3n-3 in plasma and adipose tissue. The proportion of n-3 FA in milk fat was 3.7-fold higher in the EF cows, and the n-6:n-3 ratio was decreased from 8.3 in controls to 2.3 in the EF cows. Within-group tests revealed that the C18:3n-3 content in milk fat in the EF cows was negatively correlated with milk fat percentage (r = -0.91) and yield (r = -0.89). However, no decrease in de novo synthesis of less than 16-carbon FA was found in the EF group, whereas C16:0 yields were markedly decreased. It appears that the enrichment of C18:3n-3 in milk fat was limited to approximately 2%, and the potential for increasing this n-3 FA in milk is higher for cows with lower milk fat contents. In conclusion, feeding increased amounts of C18:3n-3 during the transition period enhanced dry matter intake postpartum, increased milk production, decreased milk fat content, and improved energy balance. Increased amounts of EF considerably influenced the FA profile of plasma, adipose tissue, and milk fat. However, the extent of C18:3n-3 enrichment in milk fat was limited and was negatively correlated with milk fat content and yield.

Effects of flaxseed, raw soybeans and calcium salts of fatty acids on apparent total tract digestibility, energy balance and milk fatty acid profile of transition cows

“…In addition, cows fed diets containing WS and CSFA (n-6 FA sources) exhibited higher C18:1 trans-11 and C18:2 in milk fat than WF, which are related to human health benefits (Lock and Bauman, 2004). These results are similar to those previously cited in literature (Petit et al, 2007;Zachut et al, 2010), which reported higher concentration of C18:2 FA when cows were fed WS and CSFA. When a FA source is added to ruminant diets, most of the FA can be modified through the biohydrogenation process, which is usually not completed resulting in a wide variety of FA.…”

“…During the postpartum period, the higher EB of cows fed supplemental FA was primarily due to the increased NE L intake without decrease of DMI. Zachut et al (2010) reported higher EB when cows were fed WF than CON (2.3 and 0.8 Mcal/day, respectively); however, when evaluating EB nadir (the lowest value of EB), the authors observed −7.7 and −3.6 Mcal/day for WF and CON diet, respectively. Caldari-Torres et al (2011) also observed greater EB during postpartum for animals fed a diet rich in C18:3 FA when compared with the other diets, with the values obtained during the 7 th week of lactation (2.10, −0.10 and 4.70 Mcal/day for diets rich in saturated, C18:2 and C18:3 FA, respectively).…”

Linseed: a valuable feedstuff for ruminants

“…Nevertheless, results from feeding linseeds on reproductive variables are inconsistent. Some authors reported an improved increased follicular and corpus luteum growth , oocyte (Moallem et al, 2013;Zachut et al, 2010) and embryo quality (Thangavelu et al, 2007), decreased pregnancy loss (Ambrose et al, 2006), reduced plasma prostaglandin (Petit et al, 2002), and increased serum progesterone concentration (Jahani-Moghadam et al, 2015), reduced interval from calving to ovulation (Colazo et al, 2009). In contrast, others noted no changes in milk progesterone concentration or corpus luteum activity (Ponter et al, 2006), or oocyte quality (Bilby et al, 2006, Fouladi-Nashta et al, 2009.…”

Improving the fatty acid profile of winter milk from housed cows with contrasting feeding regimes by oilseed supplementation

“…Also in agreement with previous studies (Akraim et al, 2007;Collomb et al, 2004;Glasser et al, 2008), both oilseed supplements improved milk composition by reducing concentrations of the main nutritionally undesirable SFA (C12:0, C14:0, and C16:0) and total SFA. This may be explained by greater intake of unsaturated fats, reported to inhibit the de novo synthesis of short and medium chain saturated FA, including palmitic acid (Akraim et al, 2007;Chilliard et al, 2007;Zachut et al, 2010).…”

“…This is even more marked for longer chain n-3, such as eicosapentaenoic acid (EPA, c6c9c12c15c18 C20:5), docosapentaenoic acid (DPA, c7c10c13c16c19 C22:5) and docosahexaenoic acid (DHA, c4c7c10c13c16c19 C22:6) . Transfer rates are also reported to depend on the type of oilseed supplement used, the proportion and composition of FA in the diet, productivity of the cows and the proportion of concentrate in the diet Zachut et al, 2010). The metabolism of dietary MUFA and PUFA in the rumen involves hydrogenation to SFA; in addition, SFA leaving the rumen can be further transformed in the mammary gland before being secreted into milk.…”