Publications of Yves Beckers
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See detailVulnerability assessments in dairy cattle farms based on individual sensitivity to heat stress
Amamou, Hajer ULiege; Mahouachi, Mokhtar; Beckers, Yves ULiege et al

Poster (2020, January 31)

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See detailStrategies of the Walloon dairy producersfaced to the uncertain dairy future
Dalcq, Anne-Catherine ULiege; Dogot, Thomas ULiege; Soyeurt, Hélène ULiege et al

Conference (2020, January 31)

This study observes the strategies, and their determinants, of the Walloon dairy producersfaced to the post quota perspective through the realisation of 245 surveys, conducted from November 2014 to ... [more ▼]

This study observes the strategies, and their determinants, of the Walloon dairy producersfaced to the post quota perspective through the realisation of 245 surveys, conducted from November 2014 to February 2015. It highlights how dairy production companies plan to evolve to cope with this great change in the sector and so how will move the production of our dairy products. Three kinds of strategical variables were defined and related to the evolution of milk production (MP) [the producerswho increase MP (HighMP) vs. keep constant MP (ConstantMP) vs. stop MP]; the valorisation of MP [alternative (ValMP)vs. classical] and the diversification of activities [with (DivMP) vs. without such activities]. The relationships between the chosen strategies and the quantitative technical variables were studied using generalised linear models. The independence between qualitative technical variables and the strategical variables was tested using Chi Square test. HighMP and ConstantMP producersrepresent 38.4% and 53.9% of respondents, respectively. HighMP producerswere significantly more declared as legal entity (p-value = 0.03), had more family members on the farm (p-value<0.01), larger agricultural area in property (p-value = 0.03) and higher MP quota(p-value = 0.01)compared to ConstantMP producers. Only 9.8% of respondents decide to valorise differently MP. ValMP producerstend to have more employees (p-value = 0.08) and an agricultural area less fragmented (p-value = 0.07)than classical producers. A total of 7.8% of respondents decide to develop other activities. DivMP producerstend to have more employees (p-value = 0.10), more agricultural area in property (p-value = 0.03) and a more recent year of installation (p-value < 0.01). Finally, 44.9% of ConstantMP producersdo not want to start an alternative valorisation of MP and diversify their activities. In conclusion, a relationship exists between, amongst others, the legal status, workforce available, characteristics of the agricultural area, the dairy production and the strategy chosen by the Walloon dairy producers. [less ▲]

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See detailEtude de l’impact de la fertilisation azotée et de la fauche à l’automne sur les différentes productions d’une culture céréalière pérenne (Th. intermedium).
Fagnant, Laura ULiege; Duchêne, Olivier; Bindelle, Jérôme ULiege et al

Poster (2020, January 29)

Th. intermedium could, in the future, be used in European crop rotations. As a perennial cereal crop, the species provides over many years grains, forage and various ecosystem services. Since the species ... [more ▼]

Th. intermedium could, in the future, be used in European crop rotations. As a perennial cereal crop, the species provides over many years grains, forage and various ecosystem services. Since the species has never been studied in Belgium, the evaluation of its diverse performances and their optimization seem essential. Thus, the yields and their components were evaluated according to two agronomic levers (nitrogen fertilization and mowing). This has shown that the nitrogen fertilization of 100 Kg N/ha at tillering is particularly useful in the year of establishment, increasing grain and total dry matter yields at harvest from 0,8 to 1,5T/ha and from 4,3 to 10,6T/ha respectively. In the second year, it was the autumn mowing that had an overall positive effect on production by allowing the valorization of good quality fodder. Future researches will make it possible to refine agronomic knowledge on the crop and to establish a technical itinerary adapted to the multiple services of the species. [less ▲]

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See detailThe drying temperature and the moisture content at harvest affect the apparent metabolisable energy of two maize varieties in broiler chickens
Huart, François ULiege; Malumba Kamba, Paul ULiege; Bera, François ULiege et al

in British Poultry Science (2020)

1. The grain drying process may affect the feeding value of maize but until now, no general consensus has been reached. This knowledge is essential to manage maize nutritional value in feed and ensure ... [more ▼]

1. The grain drying process may affect the feeding value of maize but until now, no general consensus has been reached. This knowledge is essential to manage maize nutritional value in feed and ensure optimal growth performance of broiler chickens. 2. A total of 72 male Ross 308 were used in a complete randomised block design to assess the effect of initial moisture content (MC) at harvest (high or low MC after the appearance of the black layer) and drying temperature (54°C, 90°C or 125°C) on the apparent faecal digestibility and the AMEn value of two maize grain types (flint and flint-dent varieties). Moreover, the relationship between in vitro dry matter digestibility coefficient (IVDMD) and salt-soluble protein (SSP) content of dried maize grain with AMEn was assessed. 3. High drying temperature (125°C) significantly decreased the AMEn (by 0.41 MJ/kg) of the maize. Maize with high-moisture content at harvest had significantly higher AMEn than maize with low moisture content (0.38 MJ/kg) depending on the variety. Based on the combination of MC at harvest and drying temperature, an AMEn difference of about 0.65 MJ per kg of dry matter was measured during this experiment. The faecal digestibility of starch remained close to 98% with low variation between the treatments. The decrease in AMEn at high drying temperature was related to the decrease in non-starch organic matter retention (NSOMR). IVDMD and SSP content were not correlated with AMEn of dried maize (R2 < 0.1). 4. This study showed that using drying temperature below 90°C for maize grain harvested at high MC, just after the black layer development, can enhance its AMEn. The IVDMD and SSP content failed to predict the AMEn of the dried maize, but further research is required to validate the results of this study. © 2020, © 2020 British Poultry Science Ltd. [less ▲]

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See detailThe effect of hydrodynamic conditions on the monogastric-like in vitro digestion of maize flours dried at different temperatures
Huart, François ULiege; Peclers, N.; Bera, François ULiege et al

in LWT (2020), 120

The effect of hydrodynamic conditions on the in vitro digestion of two maize varieties (flint-dent and flint maize), dried at different temperatures (54 °C, 90 °C or 130 °C), was assessed. During the ... [more ▼]

The effect of hydrodynamic conditions on the in vitro digestion of two maize varieties (flint-dent and flint maize), dried at different temperatures (54 °C, 90 °C or 130 °C), was assessed. During the digestion assay, maize flours were mixed using either gentle agitation (a shaking bath) or rotational agitation at four different speeds. Increasing rotational agitation gradually increased the digestibility of the in vitro dry matter (IVDMD) and of starch (IVSD) by 15 and 20%, respectively, and also affected the rate of starch amylolysis. The increase in digestion with the mixing rate was modulated by the thermal history suffered by the feedstuff materials. The variability introduced by flour thermal histories makes it difficult to compare the digestibility of such materials of unknown origin without the standardization of mixing procedures. Flour thermal history also results in different rheological properties of samples, with potential implications for enzymatic digestion that current static in vitro protocols are not able to reproduce. In order to improve the predictive quality of static in vitro models and for a reliable comparison of the digestibility of foods and feedstuffs, hydrodynamic and mixing procedures need to be optimized and standardized. © 2019 Elsevier Ltd [less ▲]

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See detailEffects of hydrolysable tannin-treated grass silage on milk yield and composition, nitrogen partitioning and nitrogen isotopic discrimination in lactating dairy cows
Herremans, Sophie; Decruyenaere, Virginie; Cantalapiedra-Hijar, G. et al

in Animal (2020), 00

The objective of this study was to evaluate the effects of oak tannin extract (OTE) added in forage before ensiling on dairy cows fed at 92% of their digestible protein requirements. Six multiparous ... [more ▼]

The objective of this study was to evaluate the effects of oak tannin extract (OTE) added in forage before ensiling on dairy cows fed at 92% of their digestible protein requirements. Six multiparous lactating Holstein cows were used in a crossover design (two treatments × two periods). The control treatment (CON) was based on a diet including 50% of grass silage, whereas the experimental treatment (TAN) included grass silage sprayed with OTE (26 g/kg DM) just before baling. Milk yield (on average 24 kg fat protein corrected milk per day) was not affected, but both milk and rumen fatty acids profiles were impacted by OTE. Nitrogen intake (415 g N per cow per day) and nitrogen use efficiency (NUE; 0.25 on average) were not affected, but a shift from urine (-8% of N intake relatively to control, P = 0.06) to faecal N (+5%; P = 0.004) was observed with the TAN diet (P ≤ 0.05). Nitrogen apparent digestibility was thus reduced for TAN (-3%; P ≤ 0.05). The effect of OTE on ruminal and milk FA profiles suggests an impact on rumen microbiota. Nitrogen isotopic discrimination between animal proteins and diet ("15N) was evaluated as a proxy for NUE. While no differences in NUE were observed across diets, a lower "15N of plasma proteins was found when comparing TAN v. CON diets. This finding supports the concept that "15N would mainly sign the N partitioning at the metabolic level rather than the overall NUE, with the latter also being impacted by digestive processes. Our results agree with a N shift from urine to faeces, and this strategy can thus be adopted to decrease the environmental impact of ruminant protein feeding. © The Animal Consortium 2019. [less ▲]

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See detailQuel fourrage pour quelle autonomie ?
Beckers, Yves ULiege

Conference given outside the academic context (2019)

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See detailPhysiological processes as linked to heat stress effects on production traits of Holstein cows
Amamou, Hajer ULiege; Mahouachi, Mokhtar; Beckers, Yves ULiege et al

Poster (2019, August 26)

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See detailSuccessful economic management differs between intensive and extensive dairy farms
Dalcq, Anne-Catherine ULiege; Beckers, Yves ULiege; Wyzen, Benoit et al

Conference (2019, August 26)

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See detailRestoring a worn-out pasture: what impact on N2O exchanges ?
Lognoul, Margaux ULiege; Gourlez de la Motte, Louis ULiege; Naiken, Alwin ULiege et al

Poster (2019, April 08)

A paired-flux tower experiment was set up in a 40 y-o grazed pasture managed by a local farmer. A parcel under restoration was compared to a control plot. In addition to N2O flux monitoring, soil mineral ... [more ▼]

A paired-flux tower experiment was set up in a 40 y-o grazed pasture managed by a local farmer. A parcel under restoration was compared to a control plot. In addition to N2O flux monitoring, soil mineral N content (ammonium and nitrate) was measured every 10-15 days. [less ▲]

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See detailHerd position habits can bias net CO2 ecosystem exchange estimates in free range grazed pastures.
Gourlez de la Motte, Louis ULiege; Dumortier, Pierre ULiege; Beckers, Yves ULiege et al

Conference (2019, April)

The eddy covariance (EC) technique has been widely used to quantify the net CO2 ecosystem exchange (NEE) of grasslands, which is an important component of grassland carbon and greenhouse gas budgets. In ... [more ▼]

The eddy covariance (EC) technique has been widely used to quantify the net CO2 ecosystem exchange (NEE) of grasslands, which is an important component of grassland carbon and greenhouse gas budgets. In free range grazed pastures, NEE estimations are supposed to also include cattle respiration. However, cattle respiration measurement by an EC system is challenging as animals act as moving points emitting CO2 that are more or less captured by the EC tower depending on their presence in the footprint. Often it is supposed that, over the long term, cattle distribution in the pasture is homogeneous so that fluctuations due to moving sources are averaged and NEE estimates are reasonably representative of cattle respiration. In this study, we test this hypothesis by comparing daily cow respiration rate per livestock unit (LU) estimated by postulating a homogeneous cow repartition over the whole pasture with three other estimates based on animal localization data, animal scale carbon budget and confinement experiments. We applied these methods to an intensively managed free range grassland and showed that the NEE estimate based on a homogeneous cow repartition was systematically lower than the three other estimates. Consequently, in order to allow estimating the validity of this hypothesis but also to improve inter site comparisons, we advocate to compute separately pasture NEE and grazer’s respiration. In the presentation, we will propose a method based on cattle presence detection using CH4 fluxes, elimination of data with cattle and gap filling on the basis of data without cattle. For the second we propose three independent methods (animal localization with GPS, animal scale carbon budget, confinement experiments) to estimate the cattle respiration rate and discuss their use depending on site specificities. [less ▲]

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See detailInfluence of adding fibrolytic enzymes on the ruminal fermentation of date palm by-products
Abid, Khalil; Jabri, Jihene; Beckers, Yves ULiege et al

in Archiv für Tierzucht (2019), 62

This study was conducted in order to assess the influence of four doses (0, 0.5, 1, and 2 mg (g dry matter)􀀀1 of commercial fibrolytic enzymes (MAXFIBER-Ir, SHAUMANN GmbH, Wahlstedt, Germany) on in vitro ... [more ▼]

This study was conducted in order to assess the influence of four doses (0, 0.5, 1, and 2 mg (g dry matter)􀀀1 of commercial fibrolytic enzymes (MAXFIBER-Ir, SHAUMANN GmbH, Wahlstedt, Germany) on in vitro fermentation of date palm (Phoenix dactylifera) by-products: date kernels, wasted dates, floral stems, and palm fronds. Rumen contents were obtained from two non-lactating Holstein cows. Enzyme supplementation to by-products was carried out 12 h prior to incubation. Compared to the control, the enzymatic supplementation quadratically increased the extent but not the gasproduction rate of date kernel fermentation. Indeed, the potential gas production increased notably by 14.8% with the lowest enzymes dose following recorded gas production after 48, 72, and 96 h of incubation. The estimated organic-matter digestibility, metabolisable energy, and total volatile fatty acids in the incubation fluid tended to be increased with the lowest dose by 7.8 %, 8.4 %, and 13.9% respectively. For the wasted dates, this feed additive tended to linearly increase the gas production rate of fermentation with the highest dose. On the other hand, this supplementation had no effect on the ruminal fermentation of the floral stems and palm fronds. The exogenous fibrolytic enzymes were more effective on fibrous but not on lignified date palm by-products. [less ▲]

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See detailThermotolerance indicators related to production and physiological responses to heat stress of holstein cows
Amamou, Hajer ULiege; Beckers, Yves ULiege; Mahouachi, M. et al

in Journal of Thermal Biology (2019), 82

Heat stress (HS) adversely influences dairy cattle welfare and productivity. This study aimed to investigate the effects of HS on production and physiological parameters of Holstein cows. Two experiments ... [more ▼]

Heat stress (HS) adversely influences dairy cattle welfare and productivity. This study aimed to investigate the effects of HS on production and physiological parameters of Holstein cows. Two experiments each lasted 6 weeks were conducted in four Tunisian farms, firstly during summer under HS (n = 80, THI = 77) and later during autumn under thermo-neutral (n = 80, THI = 54) conditions. Respiration rate (RR), skin temperature (ST), rectal temperature (RT) and milk yield were measured, and milk samples were collected on 2 days every week during each experimental period. Temperature and relative humidity were measured inside the barn to calculate the temperature-humidity index (THI). Mixed models were used to evaluate the effects of period and the relationships between THI and physiological and production traits. Reaction norm models were applied to quantify the individual responses of cows across the trajectory of THI during the HS period. A clustering methodology was developed to identify tolerant and sensitive cows to HS based on their slope for response of physiological and production traits during HS period. In summer, RR (61 breaths/min) and ST (37.7 °C) were 2.3- and 1.3-fold higher, whereas milk yield per milking was 24% lower compared with thermo-neutral conditions. Linear relationship between THI and RR, ST and RT was observed and showed increases by 2 breaths/min, 0.5 °C and 0.04 °C per increase in one THI unit, respectively. Inversely, milk, fat and protein yields showed a drop of 0.13 kg, 0.4 g and 0.3 g per milking per increase in one THI unit, respectively. Cows qualified to be heat tolerant by our work tended to have higher RR, ST, and RT and lower to almost no decay in milk yield compared to cows qualified to be heat sensitive. Specifically, RR could be used as a reliable indicator for thermotolerance. The results of this study deepen our understanding of different aspects of HS resilience. © 2019 Elsevier Ltd [less ▲]

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See detailThe use of inulin and wheat bran only during the starter period or during the entire rearing life of broilers: effects on growth performance, small intestinal maturation, and cecal microbial colonization until slaughter age.
Li, Bing ULiege; Schroyen, Martine ULiege; Leblois, Julie et al

in Poultry Science (2019)

Inulin and wheat bran were added to broiler diets during the starter period or during the entire rearing period to investigate whether the effects of using these ingredients remained until slaughter age ... [more ▼]

Inulin and wheat bran were added to broiler diets during the starter period or during the entire rearing period to investigate whether the effects of using these ingredients remained until slaughter age. Diets containing no inulin and no wheat bran (CON), 2% inulin (IN), 10% wheat bran (WB), or 2% inulin + 10% wheat bran (IN+WB) were provided until day 11. Thereafter, each dietary treatment was further divided into a continued diet with supplementation or a control diet, resulting in 7 groups (CON, IN/IN, IN/CON, WB/WB, WB/CON, IN+WB/IN+WB, or IN+WB/CON). On day 40, 12 chickens per group were euthanized. The IN/IN group increased the cecal molar ratio of butyrate but had a lower relative abundance of Lactobacillus (P < 0.05). Additionally, the cecal molar ratio of propionate was higher in the IN/CON group compared to the IN/IN group (P = 0.034). The WB/CON group had the best results on BW and feed conversion ratio (FCR) (P < 0.05). Only the cecal molar ratio of iso-butyrate was higher in the WB/WB group (P = 0.013). Moreover, compared to the CON group, both WB/WB and WB/CON groups reduced the relative abundances of Bifidobacterium and Escherichia coli, and only the WB/WB group reduced the relative abundance of Enterobacteriaceae (P < 0.05). Both IN+WB/IN+WB and IN+WB/CON groups increased BW until day 21 and lowered the relative abundance of Bifidobacterium (P < 0.05). The IN+WB/IN+WB group increased the cecal molar ratio of butyrate but reduced the molar ratio of propionate with a higher relative abundance of Enterobacteriaceae (P < 0.05). In conclusion, the lack of positive effects induced by inulin might be explained by the dose being too high. The beneficial effects on BW, FCR, and microbiota induced by wheat bran during the starter period were lasting when supplementation was stopped, suggesting that wheat bran could be a favorable ingredient during the starter period. [less ▲]

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See detailSilage additives to reduce protein degradation during ensiling and evaluation of in vitro ruminal nitrogen degradability
Herremans, Sophie ULiege; Decruyenaere, Virginie; Beckers, Yves ULiege et al

in Grass and Forage Science (2019)

Despite the high degradability of their proteins, grass and legume silages represent an important option to reach more sustainable livestock systems. To improve the nitrogen use efficiency of these crops ... [more ▼]

Despite the high degradability of their proteins, grass and legume silages represent an important option to reach more sustainable livestock systems. To improve the nitrogen use efficiency of these crops, this study assessed the potential of several additives (chestnut tannins, oak tannins, zeolite, erythritol by-product solution and wood molasses) to reduce proteolysis in the silo and in vitro nitrogen degradability. Ryegrass (Lolium multiflorum) and red clover (Trifolium pratense) were ensiled in varying proportions in laboratory-scale silos made of vacuum-packed plastic bags. Dry-matter content, chemical composition, pH, ammonia and volatile fatty acids content were analysed after 34 days of ensiling. Ruminal nitrogen degradability was assessed in vitro (Aufrère & Cartailler, 1988). We observed that the proportion of ammonia in silage was reduced by the addition of oak tannin (−12%) and zeolite (−16%). The addition of zeolite lowered in vitro organic matter digestibility. Rapidly degradable nitrogen (1-hr degradability) was reduced in vitro by both tannins (−6.8% for chestnut and −6.6% for oak) and zeolite (−5.8%), but total degradable nitrogen (24-hr degradability) was only reduced by oak (−6.5%) and chestnut tannins (−7.3%). It suggests that tannins protected proteins from plant and bacterial enzymes by forming a complex that better resists silage fermentations and in vitro protease action. The reduction effects on proteolysis in the silo and on in vitro ruminal nitrogen degradability are limited individually but could be cumulative. Erythritol by-product solution and wood molasses had no effect on silo or in vitro proteolysis. [less ▲]

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See detailHerd position habits can bias net CO2 ecosystem exchange estimates in free range grazed pastures.
Gourlez de la Motte, Louis ULiege; Dumortier, Pierre ULiege; Beckers, Yves ULiege et al

in Agricultural and Forest Meteorology (2019), 268

The eddy covariance (EC) technique has been widely used to quantify the net CO2 ecosystem exchange (NEE) of grasslands, which is an important component of grassland carbon and greenhouse gas budgets. In ... [more ▼]

The eddy covariance (EC) technique has been widely used to quantify the net CO2 ecosystem exchange (NEE) of grasslands, which is an important component of grassland carbon and greenhouse gas budgets. In free range grazed pastures, NEE estimations are supposed to also include cattle respiration. However, cattle respiration measurement by an EC system is challenging as animals act as moving points emitting CO2 that are more or less captured by the EC tower depending on their presence in the footprint. Often it is supposed that, over the long term, cattle distribution in the pasture is homogeneous so that fluctuations due to moving sources are averaged and NEE estimates are reasonably representative of cattle respiration. In this study, we test this hypothesis by comparing daily cow respiration rate per livestock unit (LU) estimated by postulating a homogeneous cow repartition over the whole pasture with three other estimates based on animal localization data, animal scale carbon budget and confinement experiments. We applied these methods to an intensively managed free range grassland and showed that the NEE estimate based on a homogeneous cow repartition was systematically lower than the three other estimates. The bias was about 60 g C m–2 yr–1, which corresponded to around 40% of the annual NEE. The sign and the importance of this bias is site specific, as it depends on cow location habits in relation to the footprint of the EC measurements which highlight the importance of testing the hypothesis of homogeneity of cattle distribution on each site. Consequently, in order to allow estimating the validity of this hypothesis but also to improve inter site comparisons, we advocate to compute separately pasture NEE and grazer’s respiration. For the former we propose a method based on cattle presence detection using CH4 fluxes, elimination of data with cattle and gap filling on the basis of data without cattle. For the second we present and discuss three independent methods (animal localization with GPS, animal scale carbon budget, confinement experiments) to estimate the cattle respiration rate. [less ▲]

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See detailOak or chestnut tannin dose responses on silage pH, proteolysis and in vitro digestibility in laboratory-scale silos
Herremans, Sophie ULiege; Decruyenaere, Virginie; Beckers, Yves ULiege et al

in Biotechnologie, Agronomie, Société et Environnement (2019), 23(2), 59-62

Description of the subject. This short note documents the use of hydrolyzable tannins as silage additives to reduce proteolysis thanks to a laboratory-scale ensiling method. Objectives. To study oak (OTE ... [more ▼]

Description of the subject. This short note documents the use of hydrolyzable tannins as silage additives to reduce proteolysis thanks to a laboratory-scale ensiling method. Objectives. To study oak (OTE) and chestnut tannin extract (CTE) dose responses on chemical composition, pH and ammoniacal nitrogen (N-NH3) content of silage. Method. A mixture of cocksfoot, white and red clovers was ensiled in vacuum packs, with OTE or CTE at doses of 0, 10, 30, 50 and 70 g.kg-1 DM. Results. Hydrolyzable tannin extracts decreased N-NH3 content of silage up to 18% (p < 0.05). For the investigated range of doses, OTE induced a linear decrease of N-NH3 content (R² = 0.76) whereas CTE resulted in a quadratic decrease (R² = 0.68). High doses of tannin extracts reduced in vitro organic matter digestibility (OMD) by 3% (p < 0.05). Conclusions. Both tannins reduced proteolysis in silos but highest doses induced a decrease in OMD. [less ▲]

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