Energy and tannin extract supplementation for dairy cows on annual winter pastures

Abstract

Energy supplementation can increase the consumption of metabolizable energy and substrate for microbial growth, while condensed tannins aid in increasing the duodenal flow of metabolizable proteins. The objective of this study was to evaluate the effects of energy supplementation and the inclusion of tannin extract (TE) from Acacia mearnsii (Weibull Black, Tanac S. A., Montenegro, Brazil) on the production performance of dairy cows grazing on winter pastures. Nine multiparous Holstein cows in mid lactation were distributed in a 3 × 3 Latin square experimental design over three periods of 28 days (21 adaptation and 7 sampling). The treatments were: without supplementation (WS), supplementation with 4 kg of corn grain (CG), and corn grain + 80 g of tannin extract (TE). The dry matter (DM) intake from pastures was similar among treatments, but the consumption of DM of the supplement was higher in the CG treatment than that in the TE treatment. The total DM intake was higher for the supplemented animals (17.3 kg·day -1 ) than that for the unsupplemented animals (14.9 kg·day -1 ) and in the TE treatment (17.7 kg·day -1 ) than in the CG treatment (16.7 kg day -1 ). Milk production increased from the unsupplemented to the supplemented animals (20.9 to 23.5 kg, respectively), while the content of urea N in the milk decreased (12.6 to 10.5 mg·100 mL -1 , respectively). There were no differences in milk production or content of milk urea N between the CG and TE treatments. Energy supplementation is a tool for improving the nutritional profile and the performance of dairy cows in mid lactation grazing on annual winter pastures, while tannin extract aids in improving the energy balance.

Effect of using Acacia mearnsii tannin extract as a feed additive on nutritional variables and productive performance in dairy cows grazing a temperate pasture

“…There was no effect of TA on milk production or composition in the present study, which was in accordance with results reported in similar studies with dairy cows supplemented with 3.4–12.0 g/kg DM of TA (Alves et al., 2017; Griffiths et al., 2013). As a normal physiological process, dairy cows mobilize energy from body tissues to support energy requirements for milk production during early lactation and replete mobilized tissue reserves during mild and late lactation for the subsequent lactation (NRC, 2001).…”

Changing the grazing session from morning to afternoon or including tannins in the diet was effective in decreasing the urinary nitrogen of dairy cows fed a total mixed ration and herbage

“…When dairy cows were supplemented with tannin extract of Acacia mearnsii from 10.9 to 19.1 g/kg of diet DM, decreased urinary N excretion were observed, albeit in addition to negative effects on feed intake and milk yield (Grainger et al, 2009). However, milk yield did not change with inclusions below 11.0 g/ kg of diet DM (Griffiths et al, 2013;Alves et al, 2017), but neither digestibility nor urinary N excretion was evaluated in these studies.…”

“…Cows produced 7,320 kg (SD = 1,044) of milk yield in the previous lactation, and at the start of period 1, cows had an average BW of 546 kg (SD = 34), milk production of 23 kg (SD = 2.6), and were 197 DIM (SD = 12). The experiment was conducted throughout 3 successive 22-d periods, with 14 ) to determine the sample size required to detect a difference of 1 kg of milk produced, with a type I error (α) = 0.05 and a power of 80% (Festing and Altman, 2002), based on previous studies of the team and published information (Griffiths et al, 2013;Mendoza et al, 2016a,b;Ueda et al, 2016;Alves et al, 2017). The treatments tested within each Latin square consisted of a combination of PMR and 1 grazing session of 5 h, as follows: (1) morning grazing session and afternoon PMR meal (AM); (2) afternoon grazing session and morning PMR meal (PM); and (3) morning grazing session and afternoon PMR meal supplemented with 15.0 g of tannins/kg of PMR DM (TAN).…”

Extrato tanífero de Acacia mearnsii para ovelhas em lactação

“…This result is because the circulating amino acids that exceed the productive capacity of the animals can be deaminated, and N can be excreted in the urine in the form of urea. In this respect, it has been shown that the tannin extract had no significant effect on the yield and chemical composition of milk in dairy cows (ALVES et al, 2017). In contrast, cattle fed diets containing soybean meal or canola meal combined with 1.5% of the tannin extract of Acacia mearnsii presented an increase in the intestinal flow of α-amino N and non-ammonia non-microbial N, whereas the intestinal flow of microbial N and the efficiency of microbial protein synthesis were not affected (ÁVILA, 2013).…”