Skip to main content Accessibility help

Hydrolysable tannin-based diet rich in gallotannins has a minimal impact on pig performance but significantly reduces salivary and bulbourethral gland size

  • G. Bee (a1), P. Silacci (a1), S. Ampuero-Kragten (a1), M. Čandek-Potokar (a2), A. L. Wealleans (a1) (a3), J. Litten-Brown (a3), J.-P. Salminen (a4) and I. Mueller-Harvey (a3)...


Tannins have long been considered ‘anti-nutritional’ factors in monogastric nutrition, shown to reduce feed intake and palatability. However, recent studies revealed that compared with condensed tannins, hydrolysable tannins (HT) appear to have far less impact on growth performance, but may be inhibitory to the total activity of caecal bacteria. This in turn could reduce microbial synthesis of skatole and indole in the hindgut of entire male pigs (EM). Thus, the objective of this study was to determine the impact of a group of dietary HT on growth performance, carcass traits and boar taint compounds of group housed EM. For the study, 36 Swiss Large White boars were assigned within litter to three treatment groups. Boars were offered ad libitum one of three finisher diets supplemented with 0 (C), 15 (T15) or 30 g/kg (T30) of HT from day 105 to 165 of age. Growth performance, carcass characteristics, boar taint compounds in the adipose tissue and cytochrome P450 (CYP) isoenzymes CYP2E1, CYP1A2 and CYP2A19 gene expression in the liver was assessed. Compared with C, feed efficiency but not daily gain and daily feed intake was lower (P<0.05) in T15 and T30 boars. Except for the percentage carcass weight loss during cooling, which tended (P<0.10) to be greater in T30 than C and T15, carcass characteristics were not affected by the diets. In line with the numerically lower androstenone level, bulbourethral and salivary glands of T30 boars were lighter (P<0.05) than of T15 with intermediate values for C. Indole level was lower (P<0.05) in the adipose tissue of T30 than C pigs with intermediate levels in T15. Skatole levels tended (P<0.10) to be lower in T30 and C than T15 pigs. Hepatic gene expression of CYP isoenzymes did not differ between-treatment groups, but was negatively correlated (P<0.05) with androstenone (CYP2E1 and CYP1A2), skatole (CYP2E1, CYP2A) and indole (CYP2A) level. In line with the numerically highest androstenone and skatole concentrations, boar taint odour but not flavour was detected by the panellists in loins from T15 compared with loins from C and T30 boars. These results provide evidence that HT affected metabolism of indolic compounds and androstenone and that they affected the development of accessory sex glands. However, the effects were too small to be detected by sensory evaluation.

  • View HTML
    • Send article to Kindle

      To send this article to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the or variations. ‘’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Hydrolysable tannin-based diet rich in gallotannins has a minimal impact on pig performance but significantly reduces salivary and bulbourethral gland size
      Available formats

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Hydrolysable tannin-based diet rich in gallotannins has a minimal impact on pig performance but significantly reduces salivary and bulbourethral gland size
      Available formats

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Hydrolysable tannin-based diet rich in gallotannins has a minimal impact on pig performance but significantly reduces salivary and bulbourethral gland size
      Available formats


This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (, which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.

Corresponding author


Hide All
Abarikwu, SO, Akiri, OF, Durojaiye, MA and Alabi, AF 2014. Combined administration of curcumin and gallic acid inhibits gallic acid-induced suppression of steroidogenesis, sperm output, antioxidant defenses and inflammatory responsive genes. The Journal of Steroid Biochemistry and Molecular Biology 143, 4960.
Aluwe, Md, Langendries, KCM, Bekaert, KM, Tuyttens, FAM, De Brabander, DL, De Smet, S and Millet, S 2013. Effect of surgical castration, immunocastration and chicory-diet on the meat quality and palatability of boars. Meat Science 94, 402407.
Ampuero Kragten, S, Verkuylen, B, Dahlmans, H, Hortos, M, Garcia-Regueiro, JA, Dahl, E, Andresen, O, Feitsma, H, Mathur, PK and Harlizius, B 2011. Inter-laboratory comparison of methods to measure androstenone in pork fat. Animal 5, 16341642.
Antongiovanni, M, Minieri, S and Petacchi, F 2007. Effect of tannin supplementation on nitrogen digestibility and retention in growing pigs. Italian Journal of Animal Science 6 (suppl. 1), 245247.
Bee, G, Chevillon, P and Bonneau, M 2015. Entire male pig production in Europe. Animal Production Science 55, 13471359.
Bee, G, Guex, G and Herzog, W 2004. Free-range rearing of pigs during the winter: adaptations in muscle fiber characteristics and effects on adipose tissue composition and meat quality traits. Journal of Animal Science 82, 12061218.
Bee, G, Jacot, S, Guex, G and Biolley, C 2008. Effects of two supplementation levels of linseed combined with CLA or tallow on meat quality traits and fatty acid profile of adipose and different muscle tissues in slaughter pigs. Animal 2, 800811.
Bi, J and O’Mahony, M 2007. Updated and extended table for testing the significance of the R-index. Journal of Sensory Studies 22, 713720.
Biagia, G, Cipollini, I, Paulicks, BR and Roth, FX 2010. Effect of tannins on growth performance and intestinal ecosystem in weaned piglets. Archives of Animal Nutrition 64, 121135.
Bonneau, M and Chevillon, P 2012. Acceptability of entire male pork with various levels of androstenone and skatole by consumers according to their sensitivity to androstenone. Meat Science 90, 330337.
Čandek-Potokar, M, Škrlep, M, Batorek Lukač, N, Zamaratskaia, G, Prevolnik Povše, M, Velikonja Bolta, Š, Kubale, V and Bee, G 2015. Hydrolysable tannin fed to entire male pigs affects intestinal production, tissue deposition and hepatic clearance of skatole. The Veterinary Journal 204, 162167.
Cantos, E, Espín, JC, López-Bote, C, de la Hoz, L, Ordóñez, JA and Tomás-Barberán, FA 2003. Phenolic compounds and fatty acids from acorns (Quercus spp.), the main dietary constituent of free-ranged Iberian pigs. Journal of Agricultural and Food Chemistry 51, 62486255.
Cousins, BW, Tanksley, TD, Knabe, DA and Zebrowska, T 1981. Nutrient digestibility and performance of pigs fed sorghums varying in tannin concentration. Journal of Animal Science 53, 15241537.
Cava, R, Ventanas, J, Florencio Tejeda, J, Ruiz, J and Antequera, T 2000. Effect of free-range rearing and α-tocopherol and copper supplementation on fatty acid profiles and susceptibility to lipid oxidation of fresh meat from Iberian pigs. Food Chemistry 68, 5159.
Dias, TR, Alves, MG, Oliveira, PF and Silva, BM 2014. Natural products as modulators of spermatogenesis: the search for a male contraceptive. Current Molecular Pharmacology 7, 154166.
Doran, E, Whittington, FW, Wood, JD and McGivan, JD 2002. Cytochrome P450IIE1 (CYP2E1) is induced by skatole and this induction is blocked by androstenone in isolated pig hepatocytes. Chemico-Biological Interactions 140, 8192.
Engström, MT, Pälijärvi, M and Salminen, J-P 2015. Rapid fingerprint analysis of plant extracts for ellagitannins, gallic acid, and quinic acid derivatives and quercetin-, kaempferol- and myricetin-based flavonol glycosides by UPLC-QqQ-MS/MS. Journal of Agricultural and Food Chemistry 63, 40684079.
Espín, JC, González-Barrio, R, Cerdá, B, López-Bote, C, Rey, AI and Tomás-Barberán, FA 2007. Iberian pig as a model to clarify obscure points in the bioavailability and metabolism of ellagitannins in humans. Journal of Agricultural and Food Chemistry 55, 1047610485.
Ferguson, NS, Gous, RM and Iji, PA 2003. Determining the source of anti-nutritional factor(s) found in two species of lupin (L. albus and L. angustifolius) fed to growing pigs. Livestock Production Science 84, 8391.
Hagerman, AE, Robbins, CT, Yohan, W, Wilson, TC and McArthur, C 1992. Tannin chemistry in relation to digestion. Journal of Range Management 45, 5762.
Hansen-Møller, J 1994. Rapid high-performance liquid chromatographic method for simultaneous determination of androstenone, skatole and indole in back fat from pigs. Journal of Chromatography B: Biomedical Sciences and Applications 661, 219230.
Johnson, MTJ, Ives, AR, Ahern, J and Salminen, JP 2014. Macroevolution of plant defenses against herbivores in the evening primroses. New Phytologist 203, 267279.
Knarreborg, A, Beck, J, Jensen, MT, Laue, A, Agergaard, N and Jensen, BB 2002. Effect of non-starch polysaccharides on production and absorption of indolic compounds in entire male pigs. Animal Science 74, 445453.
Koller, M 2013. Robust estimation of linear mixed models. PhD thesis, ETH Zurich, Zurich, Switzerland.
Koller, M 2014. robustlmm: Robust Linear Mixed Effects Models. R package version 1.4-2. Retrieved on 10 March 2015 from
Korobkova, EA 2015. Effect of natural polyphenols on CYP metabolism: implications for diseases. Chemical Research in Toxicology 28, 13591390.
Mariscal-Landín, G, Lebreton, Y and Sève, B 2002. Apparent and standardised true ileal digestibility of protein and amino acids from faba bean, lupin and pea, provided as whole seeds, dehulled or extruded in pig diets. Animal Feed Science and Technology 97, 183198.
Meier-Dinkel, L, Gertheiss, J, Müller, S, Wesoly, R and Mörlein, D 2015. Evaluating the performance of sensory quality control: the case of boar taint. Meat Science 100, 7384.
Moilanen, J, Sinkkonen, J and Salminen, JP 2013. Characterization of bioactive plant ellagitannins by chromatographic, spectroscopic and mass spectrometric methods. Chemoecology 23, 165179.
Mueller-Harvey, I 2006. Unravelling the conundrum of tannins in animal nutrition and health. Journal of the Science of Food and Agriculture 86, 20102037.
Nagata, Y and Takeuchi, N 2003. Measurement of odor threshold by triangle odor bag method. Odor Measurement Review 118, 118127.
O’Mahony, M 1988. Sensory difference and preference testing: the use of signal detection measures. In Applied Sensory Analysis of Food (ed. H Moskowitz), p. 148, CRC Press, Boca Raton, FL.
O’Mahony, M 1992. Understanding discrimination tests: a user-friendly treatment of response bias, rating and ranking R-index tests and their relationship to signal detection. Journal of Sensory Studies 7, 147.
Pauly, C, Spring, P, Doherty, JV, Ampuero Kragten, S and Bee, G 2008. Performances, meat quality and boar taint of castrates and entire male pigs fed a standard and a raw potato starch-enriched diet. Animal 2, 17071715.
Rasmussen, MK, Zamaratskaia, G and Ekstrand, B 2011. In vivo effect of dried chicory root (Cichorium intybus L.) on xenobiotica metabolising cytochrome P450 enzymes in porcine liver. Toxicology Letters 200, 8891.
Stukelj, M, Valencak, Z, Krsnik, M and Svete, AN 2010. The effect of the combination of acids and tannin in diet on the performance and selected biochemical, haematological and antioxidant enzyme parameters in grower pigs. Acta Veterinaria Scandinavica 52, 19.
Wesoly, R and Weiler, U 2012. Nutritional influences on skatole formation and skatole metabolism in the pig. Animals 2, 221242.
Wiercinska, P, Lou, Y and Squires, EJ 2012. The roles of different porcine cytochrome P450 enzymes and cytochrome b5A in skatole metabolism. Animal 6, 834845.
Xue, J and Dial, GD 1997. Raising intact male pigs for meat: detecting and preventing boar taint. Swine Health and Production 5, 151158.
Ye, J, Coulouris, G, Zaretskaya, I, Cutcutache, I, Rozen, S and Madden, T 2012. Primer-BLAST: a tool to design target-specific primers for polymerase chain reaction. BMC Bioinformatics 13, 134.


Type Description Title
Supplementary materials

Bee supplementary material
Table S1

 Word (27 KB)
27 KB


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed