Effects of supplementing fish oil in the drinking water of dairy cows on production performance and milk fatty acid composition1

Abstract

The objective of this study was to determine the effects of supplementing fish oil (FO) in the drinking water of dairy cows on production performance and milk fatty acid composition. Sixteen multiparous Holstein dairy cows (741 +/- 84 kg of BW; 60 +/- 2.3 d in milk, mean +/- SD) housed in a tie-stall facility were used in the study. The study was conducted as a completely randomized design with repeated measurements. The cows were blocked by days in milk and allocated to 1 of 2 treatments: 10 g of menhaden FO/kg of DM top-dressed on the total mixed ration (FOT), and 2 g of menhaden FO/L delivered in the drinking water (FOW). The trial lasted for 5 wk: a 1-wk pretreatment adjustment period and 4 wk of treatment. The animals were fed and milked twice daily (feeding at 0830 and 1300; milking at 0500 and 1500) and had unlimited access to water. Dry matter intake (21.3 kg/d for FOT vs. 22.7 +/- 0.74 kg/d for FOW), milk yield (38.2 kg/d for FOT vs. 39.5 +/- 1.9 kg/d for FOW), and water intake (101 L/d for FOT vs. 107 +/- 4.4 L/d for FOW) were not affected by treatment. The mode of delivery of FO had no effect on milk fat percentage, but milk fat percentage declined linearly with time. The fatty acid contents of 7:0; 8:0; 9:0; 10:0; 12:0 in the milk of FOT cows were lower than for FOW cows, whereas 18:1 trans-12; 18:1 trans-13 and 14; 18:1 trans-16; and trans-9, trans-11 plus trans-10, trans-12 CLA were greater for FOT than for FOW. The contents of 24:1 in the milk of FOW cows were 48% greater than for FOT cows, although the concentrations were low in both groups. There was a tendency for the contents of 14:0 and 22:5n-6 to be greater in FOW cows than FOT cows and for the contents of iso-18:0 to be lower for FOW cows than for FOT cows. Although it appears that the amount of FO added in the study did not bypass the rumen as hypothesized, these results suggest that drinking water can be an alternative for supplementing FO to dairy cows without decreasing feed or water intake relative to cows fed FO in the diet.

Branched Chain Fatty Acid Content of United States Retail Cow's Milk and Implications for Dietary Intake

“…The mean BCFA levels reported in the present study fall within the range previously reported in studies that measured cow’s milk FA in response to various diets in small scale experimental studies [3-5, 8, 10]. …”

“…Both iso - and anteiso -13:0 BCFA in cow’s milk have been reported by some [3, 5, 8, 11] but not by others [4, 6, 26]. In the present study, retail milk samples were obtained from processing plants and represent pooled milk from many farms; use of specific feeds on some farms that may support small amounts of ruminal C13 BCFA could be diluted to below detection limits by the milk from other farms [10, 27].…”

Effect of dietary fish oil on milk yield, fatty acids content and serum metabolic profile in dairy cows

“…Concentration of VA in milk fat followed the same pattern of temporal changes as cis ‐9 trans ‐11 CLA. FOM supplementation in TMR doses of cows resulted in a higher increase in the concentration of cis‐ 9, trans ‐12 CLA isomer (1.33%) in milk fat compared with FO supplementation in drinking water (0.88%) (Osborne et al., 2008). Our experiment as well as other studies (AbuGhazaleh et al., 2004; Castañeda‐Gutieérrez et al., 2007) demonstrated a significant increase in VA content in milk after FO supplementation.…”

“…This study contained 33% of herring‐sprat oil, which characterized high percentage of 40.43% of PUFA including 29.5% the omega‐3 family (n‐3), polyunsaturated fatty acids n‐3 such as EPA (8.19%) and DHA (13.83%). In other studies, mainly fish oil delivered from menhaden fish, which contained the lower DHA content (ranging 10.95–11.92 g/100 g fatty acids), was used (AbuGhazaleh et al., 2003; Osborne et al., 2008). In the beginning of the study, the content of DHA was below detection (<10 −3 ) in the milk fat of the control cows.…”

“…The addition of FO to dairy cow diets resulted in incorporation of long chain omega‐3 FA like eicosapentaenoic (EPA; C20:5 n‐3), and docosahexaenoic acids (DHA; C22:6 n‐3) into the milk (Chouinard et al., 2001; AbuGhazaleh et al., 2003; Osborne et al., 2008). The ability of fish oil to promote VA accumulation in the rumen has been attributed largely to its docosahexaenoic count (Chilliard et al., 2001; AbuGhazaleh and Jenkins, 2004).…”