Effect of quebracho-chestnut tannin extracts at 2 dietary crude protein levels on performance, rumen fermentation, and nitrogen partitioning in dairy cows

Abstract

Our objective was to determine the effects of a tannin mixture extract on lactating cow performance, rumen fermentation, and N partitioning, and whether responses were affected by dietary crude protein (CP). The experiment was conducted as a split-plot with 24 Holstein cows (mean ± standard deviation; 669±55kg of body weight; 87±36 d in milk; 8 ruminally cannulated) randomly assigned to a diet of [dry matter (DM) basis] 15.3 or 16.6% CP (whole plot) and 0, 0.45, 0.90, or 1.80% of a tannin mixture in three 4×4 Latin squares within each level of CP (sub-plot). Tannin extract mixture was from quebracho and chestnut trees (2:1 ratio). Dietary CP level did not influence responses to tannin supplementation. A linear decrease in DM intake (25.5 to 23.4kg/d) was found, as well as a linear increase in milk/DM intake (1.62 to 1.75) and a trend for a linear decrease in fat-and-protein-corrected milk (38.4 to 37.1kg/d) with increasing levels of tannin supplementation. In addition, there was a negative linear effect for milk urea N (14.0 to 12.9mg/dL), milk protein yield (1.20 to 1.15kg), and concentration (2.87 to 2.83%). Furthermore, the change in milk protein concentration tended to be quadratic, and predicted maximum was 2.89% for a tannin mixture fed at 0.47% of dietary DM. Tannin supplementation reduced ruminal NH3-N (11.3 to 8.8mg/dL), total branched-chain volatile fatty acid concentration (2.97 to 2.47mol/100mol), DM, organic matter, CP, and neutral detergent fiber digestibility. Dietary tannin had no effect on intake N (587±63g/d), milk N (175±32g/d), or N utilization efficiency (29.7±4.4%). However, feeding tannin extracts linearly increased fecal N excretion (214 to 256g/d), but reduced urinary N (213 to 177g/d) and urinary urea N (141 to 116g/d) excretion. Decreasing dietary CP did not influence milk production, but increased N utilization efficiency (milk N/N intake; 0.27 to 0.33), and decreased milk urea N (15.4 to 11.8mg/dL), ruminal NH3-N (11.0 to 9.3mg/dL), apparent digestibility of DM (66.1 to 62.6%), organic matter (68.2 to 64.3%), and CP (62.9 to 55.9%), as well as urinary N excretion (168 vs. 232g/d). Results of this study indicated beneficial effects of 0.45% tannin extract in the diet on milk protein content. Increasing tannin extract levels in the diet lowered urinary N excretion, but had detrimental effects on DM intake, milk protein content, milk protein yield, and nutrient digestibility.

The role of condensed tannins in ruminant animal production: advances, limitations and future directions

“…However, the effective reduction of CP degradation was not proportional to the two-fold increase in CT (Bruno- Soares et al, 2011). Quebracho tannin extract (QTE) is a commercially available CT source from Schinopsis spp., consistently reported to decrease ruminal CP degradation at multiple dietary fiber (Dschaak et al, 2011) and CP levels (Aguerre et al, 2016). Responses appear to be doserelated as increasing inclusion from 1 to 6% of DM linearly decrease ruminal CP degradation (Ahnert et al, 2015).…”

“…However, microbial protein production was improved in a birdsfoot trefoil diet suggesting a more efficient use of dietary N when a CT-containing forage was offered in replacement for alfalfa. As rumen NH 3 is reduced, CT shift N excretion from the urine to feces (Deaville et al, 2010;Williams et al, 2011;Hymes-Fecht et al, 2013;Ahnert et al, 2015;Orlandi et al, 2015;Aguerre et al, 2016), which may substantially improve environmental sustainability of ruminant production through reduced nitrous oxide emissions from manure (Powell et al, 2010). The effect of CT on microbial protein synthesis and microbial growth efficiency are much less clear compared with the well-established responses on ruminal CP degradation and NH 3 concentrations.…”

Effect of sainfoin hay and pomegranate peel extracts on in vitro fermentation and protein degradation using the RUSITEC technique

“…The effects of plant extracts rich in polyphenolic compound on total VFA and VFA profiles varied among studies, and are dependent on source, rate and dosage of polyphenolic compound. On the other hand, Carulla et al (2005) found no effect of tannins on total VFA in sheep supplemented with black wattle tree, whereas, Beauchemin et al (2007) reported a decrease in acetate molar proportion when cattle were fed quebracho, with a tendency to a decrease in total VFA. In the present study, PPE decreased the concentration of BCVFA and increased the concentration of acetate.…”

“…Aguerre et al (2010) reported that at a lower concentration of condensed tannins (4.5 g tannins extracts kg…”

“…Residues were ground through a 1-mm screen (standard model 4, Arthur Thomas Co., Philadelphia, PA) for chemical analysis. Organic matter (OM) was analyzed according to AOAC (1995); method 942.05). Total N was determined using a combustion analyzer (NA 2100, Carlo Erba Instruments, Milan, Italy).…”