Effect of dietary quebracho tannin extract on milk fatty acid composition in cows

Abstract

The aim of this study was to examine the capacity of quebracho tannin extract (QTE) to modulate the fatty acid (FA) profile in the milk fat of cows. Fifty Holstein cows yielding 33.2 ± 8.2 kg/d of milk were divided into 2 groups. The cows were fed a basal diet with a forage-concentrate ratio of 66:34 on a dry matter (DM) basis. Diets tested were control (CON, basal diet without QTE) and basal diet plus 15 or 30 g of QTE/kg of DM (QTE and QTE, respectively). Two treatments could be tested simultaneously and were arranged along 6 periods. The milk FA profile was characterized by increments in the proportion of linoleic (LA) and α-linolenic acid (α-LNA) (QTE = 10 and 6.1%; QTE = 28 and 25%, respectively) compared to CON, which might indicate reduced ruminal biohydrogenation (BH) of both dietary LA and α-LNA. Vaccenic acid (VA) in the milk fat was reduced (QTE 8.9% and QTE 12%) compared to CON, which may be linked to inhibited BH of LA and α-LNA. Rumenic acid (RA), a conjugated LA (cis-9,trans-11 conjugated linoleic acid) and an important human health promoter, was unfortunately decreased (QTE 8.3% and QTE 16%) in the milk compared with CON, probably because of inhibited ruminal BH of LA. However, reduced RA in the milk was probably due to reduced availability of VA produced in the rumen and the consequently low VA available to be desaturated to RA in the mammary gland by Δ-desaturase. The proportions of total polyunsaturated FA were increased with QTE and QTE by 4.7 and 15% compared to CON, respectively, and the long-chain FA proportions were also increased (QTE 2.0% and QTE 8.2%). Moreover, myristic and palmitic acid were reduced by QTE (9.6 and 3.3%, respectively) compared to CON, which also contributed to increasing the nutritional quality of milk because they are recognized to increase high-density lipoprotein in humans. Branched-chain FA in milk was reduced with QTE treatments, which indicates inhibited ruminal BH and microbial activity. In general, our findings suggest that dietary QTE have the potential to modulate FA profile of milk fat, and this effect is dosage dependent. Because QTE influenced the FA profile of milk fat both positively and negatively, further research is needed before concluding that QTE may improve the nutritional quality of cow milk fat in human diets.

Sainfoin (Onobrychis viciifolia) silage in dairy cow rations reduces ruminal biohydrogenation and increases transfer efficiencies of unsaturated fatty acids from feed to milk

“…The transfer efficiency from feed to milk of C18:3n-3 in cows fed the sainfoin diet was correspondingly increased. The current results are in agreement with findings of Henke et al. (2017) and Kälber et al.…”

Effects of berry seed residues on ruminal fermentation, methane concentration, milk production, and fatty acid proportions in the rumen and milk of dairy cows

“…Phytofactors including tannins can reduce the number of protozoa and microorganisms actively influencing rumen fermentations (Makkar et al, 1995;Szumacher-Strabel and Cieslak, 2010;Henke et al, 2017). It has been shown that increasing concentrations of condensed tannins from quebracho extract decreased entodiniomorph (0.2 mg of tannins/mL of rumen fluid) and holotrich (0.05 and 0.1 mg of tannins/mL of rumen fluid) populations (Carulla et al, 2005).…”

“…The bioactive substances may also modulate ruminal fatty acid (FA) biohydrogenation leading to changes in rumen and milk FA profile (Henke et al, 2017). For instance, quebracho condensed tannins inhibit one of the bacterial species involved in ruminal biohydrogenation, Butyrivibrio proteoclasticus (Buccioni et al, 2015) and consequently may improve the quality of milk by increasing UFA contents (Henke et al, 2017). The possibility of using berry by-products in animal nutrition may allow for the production of healthy animal-derived foods and mitigation of enteric methane emission, hence an environmentally friendly production system.…”

The effect of oak tannin (Quercus robur) and hops (Humulus lupulus) on dietary nitrogen efficiency, methane emission, and milk fatty acid composition of dairy cows fed a low-protein diet including linseed

“…Studies on the effects of tannins on milk fatty acid profile are more limited and inconsistent. Henke et al (2017) reported that the addition of quebracho tannin (15 and 30 g/kg of DM) to diets of lactating dairy cows modulates the fatty acid profile of milk fat with a dose-dependent effect. The concentrations of LA and ALA were increased and concentrations of myristic acid (14:0) and palmitic acid (16:0) were reduced at the highest dosage of tannin.…”