Effects of feeding micronised flaxseed on yield and composition of milk from Holstein cows

Abstract

Nine multiparous Holstein cows were used in three 3 × 3 Latin squares to investigate the effects of feeding unheated and micronised flaxseed on milk yield and milk fatty acid composition. Three diets were formulated to meet the nutrient requirement of dairy cows in early lactation: a control diet with no added flaxseed (NFS), an unheated flaxseed diet (UFS) and a micronised flaxseed diet (MFS). The level of flaxseed in UFS and MFS was 70 g kg −1 of the diet dry matter (DM). Feeding flaxseed to dairy cows had no effect on DM intake or milk yield. However, energy-corrected milk was higher (P < 0.05) for cows fed MFS than for those fed UFS or NFS. Supplemental flaxseed reduced (P < 0.05) the milk fat percentage without affecting the concentration of milk protein or milk lactose. However, the yield of milk components was not affected by feeding flaxseed. The concentrations of short-chain (C 4:0 to C 12:0 ) and medium-chain (C 14:0 to C 17:0 ) fatty acids were decreased (P < 0.05) while those of long-chain fatty acids (C 18:0 to C 18:3 ) were increased (P < 0.05) in the milk of cows fed UFS and MFS compared with cows fed NSF. Feeding flaxseed to dairy cows can alter the milk fatty acid composition, but only minor effects on milk fatty acid composition can be expected by feeding micronised versus unheated flaxseed.

Colostrum and milk fatty acids of dairy cows as influenced by extruded linseed supplementation during the transition period

“…Colostrum and Milk as well as Efficiency of 18:3 Transfer from Feed to Milk In general, the present results agree with the literature (Mustafa et al 2003;Petit and Benchaar 2007), with linseed supplementation increasing concentrations of various 18 FA, while the control supplement favoured 16:0. In addition, the associated changes in the other FA and respective groups of FA were as expected.…”

Feeding micronized and extruded flaxseed to dairy cows: Effects on digestion and ruminal biohydrogenation of long-chain fatty acids

“…The FA profiles of the three flaxseed treatments were similar, although some small differences in C 18:3 and total fatty acids were noted. Fatty acid concentrations of flaxseed were similar to those reported by other researchers (Petit 2003;Mustafa et al 2003a). Total FA of dietary treatments increased from 35 g kg -1 for C to 72 g kg -1 for the flaxseed supplemented diets (Table 3).…”

“…Flaxseed (Linum usitatissimum) contains 400 g kg -1 fat with α-linolenic acid constituting approximately 55% of total FA (Mustafa et al 2002;Petit 2003). Feeding flaxseed to dairy cows increased the concentrations of short-and mediumchain FA and increased the concentrations of LCFA (Mustafa et al 2003a;Petit 2003). However, the increase in α-linolenic acid content was small (i.e., 13%), suggesting that the majority of unsaturated FA were subjected to extensive biohydrogenation (BH) in the rumen (Palmquist and Jenkins 1980).…”

Use of flaxseed (Linum usitatissimum) in the diet of dairy cows: Review

“…However, this treatment had no effect on the biohydrogenation of the fatty acids from flaxseed and did not affect the amount of amino acids post-ruminal (Mustafa et al, 2003).…”

“…The extrusion of oil seeds tends to reduce protein in the rumen degradation and increase milk production (Grumpelt & Ingalls, 1984). However, in extruded linseed seeds is not effective in increasing the supply of amino acids postruminal (Mustafa et al, 2003), increasing the protein in the rumen, but reducing the same digestibility in lactating cows (Gonthier et al, 2004). Dairy cows in the middle of lactation, when fed with 12.6% of extruded linseed seed, in the dry matter, and compared to the control treatment (without linseed) 0.4% reduction in milk production (Martin et al, 2008).…”