Effects of Particle Size of Barley on Intestinal Morphology, Growth Performance and Nutrient Digestibility in Pigs

  • Morel, P.C.H. (Institute of Food, Nutrition and Human Health, Massey University) ;
  • Cottam, Y.H. (Institute of Food, Nutrition and Human Health, Massey University)
  • Received : 2006.11.10
  • Accepted : 2007.05.14
  • Published : 2007.11.01


A growth trial and a digestibility trial were conducted to examine the effect of feed particle size on the performance, nutrient digestibility, gastric ulceration and intestinal morphology in pigs fed barley-based diets. Barley was processed through a hammer mill to achieve four diets varying in particle size (average particle $size{\pm}standard $deviation): coarse ($1,100{\pm}2.19\;{\mu}m$), medium ($785{\pm}2.23\;{\mu}m$), fine ($434{\pm}1.70\;{\mu}m$) and mixed (1/3 of coarse, medium and fine) ($789{\pm}2.45\;{\mu}m$). Sixty-four entire male pigs were used in the growth trial and the diets were fed ad libitum between 31 kg and 87 kg live weight. Following slaughter, stomach and ileal tissues were scored for integrity (ulceration or damage) and histological measurements taken. Twenty-four entire male pigs were used in the digestibility trial, which involved total faecal collection. Over the entire growth phase, there were no differences (p>0.05) in average daily gain and feed conversion ratio between pigs fed diets of different particle size. Pigs fed the coarse and medium diets had lower (p<0.05) stomach ulceration scores (0.20 and 0.25, respectively, on a scale from 0 to 3) than those fed the mixed (0.69) or the fine diets (1.87). The stomachs of all animals fed the fine diet had lesions and stomach ulcerations were present only in this group. Pigs fed the fine diet had thicker (p<0.001) ileal epithelial cell layer with no differences (p>0.05) being observed for villous height or crypt depth. Faecal digestibility coefficients of neutral and acid detergent fibre were the highest (p<0.05) for the mixed diet, intermediate for the fine and coarse diets and the lowest for the medium diet. A similar numerical trend (p = 0.103) was observed for the apparent faecal energy digestibility coefficient. It is concluded that, with barley based diets, a variation in average particle size between $400{\mu}m$ and $1,100{\mu}m$ had no effect on pig performance but the fine dietary particle size affected the integrity of the stomach, as well as the structure of the small intestine, thus compromising overall gut health. Our data also demonstrate that changes in particle size distribution during the digestion process, rather than average particle size or particle size variation, are related to apparent faecal digestibility.


Pig;Particle Size;Intestinal Morphology;Barley


  1. Albar, J., F. Skiba and E. R. Garnier. 2000. Incidence de la granulometrie sur les performances en post-sevrage et la digestibilite de quatres aliments A base d'orge, de ble, de mais et de pois. In Journees de la Recherche Porcine en France 32. pp. 193-200.
  2. AOAC. 2000. Official methods of analysis of AOAC International. Horwitz W, editor. 17th ed: Washington, DC: The Association, USA.
  3. Healy, B. J., J. D. Hancock, G. A. Kennedy, P. J. Bramelcox, K. C. Behnke and R. H. Hines. 1994. Optimum particle size of corn and hard and soft sorghum for nursery pigs. J. Anim. Sci. 72(9):2227-2236.
  4. Dong, G. Z. and J. R. Pluske. 2007. The low feed intake in newlyweaned pigs: problems and possible solutions. Asian-Aust. J. Anim. Sci. 20(3):440-452.
  5. Eisemann, J. H. and R. A. Argenzio. 1999. Effect of diets differing in propensity to promote gastric lesions on defense systems in gastric mucosae. J. Anim. Sci. 77:2715-2720.
  6. Guillou, D. and E. Landau. 2000. Granulometrie et nutrition porcine. Prod. Anim. 13(2):137-145.
  7. Dirkzwager, A., A. R. W. Elbers, P. J. van der Aar and J. H. Vos. 1998. Effect of particle size and addition of sunflower hulls to diets on the occurrence of oesophagogastric lesions and performance in growing-finishing pigs. Livest. Prod. Sci. 56:53-60.
  8. Cole, J. T., J. L. Gookin, J. M. Gayle, J. H. Eisemann, R. A. Argenzio and A. T. Blikslager. 2002. Endoscopy via a gastric cannula to monitor the development of ulcers in the pars esophagea in pigs after consumption of a finely ground feed combined with a period of withholding of feed. Am. J. Vet. Res. 63(8):1076-1082.
  9. Brunsgaard, G. 1998. Effects of cereal type and feed particule size on morphological characteristics, epithelial cell proliferation, and lectin binding patterns in the large intestine of Pigs. J. Anim. Sci. 76:2787-2798.
  10. Choct, M., E. A. D. Selby, D J. Cadogan and R. G. Campbell. 2004. Effects of particle size, processing, and dry or liquid feeding on performance of piglets. Austral. J. Agric. Res. 55(2):237-245.
  11. Hedemann, M. S., L. L. Mikkelsen and P. J. B. Naughton. 2005. Effect of feed particle size and feed processing on morphological characteristics in the small and large intestine of pigs and on adhesion of Salmonella enterica serovar Typhimurium DT12 in the ileum in vitro. J. Anim. Sci. 83:1554-1562.
  12. Kim, I. H., J. D. Hancock, J. W. Hong, M. R. Cabrera, R. H. Hines and K. C. Behnke. 2002. Corn particle size affects nutritional value of simple and complex diets for nursery pigs and broilers chicks. Asian-Aust. J. Anim. Sci. 15(6):872-877.
  13. Lentle, R. G., V. Ravindran, G. Ravindran and D. V. Thomas. 2006. Influence of feed particle size on efficiency of broiler chickens fed wheat-based diets. J. Poult. Sci. 43:135-142.
  14. Livesey, G. 1991. Calculating the energy values of foods: towards new empirical formulae based on diets with varied intakes of unavailable complex carbohydrates. Eur. J. Clin. Nutr. 45:1-12.
  15. Laurinen, P., H. Siljander-Rasi, J. Karhunen, T. Alaviuhkola, M. Nasi and K. Tuppi. 2000. Effects of different grinding methods and particle size of barley and wheat on pig performance and digestibility. Anim. Feed Sci. Tech. 83(1):1-16.
  16. Lawrence, K. R., C. W. Hastad, R. D. Goodband, M. D. Tokach, S. S. Dritz, J. L. Nelssen, J. M. DeRouchey and M. J. Webster. 2003. Effects of soybean meal particle size on growth performance of nursery pigs. J. Anim. Sci. 81(9):2118-2122.
  17. Lawrence, T. L. J. 1970. Some effects of including differently processed barley in the diet of the growing pig: growth rate, food conversion efficiency, digestibility and rate of passage through the gut. Anim. Prod. 12:139-150.
  18. Mavromichalis, I. , J. D. Hancock, B. W. Senne, T. L. Gugle, G. A. Kennedy, R. H. Hines and C. L. Wyatt. 2000. Enzyme supplementation and particle size of wheat in diets for nursery and finishing pigs. J. Anim. Sci. 78(12):3086-3095.
  19. Morel, P. C. H., J. R. Pluske, G. Pearson and P. J. Moughan. 1999. A Standard Nutrient Matrix for New Zealand Feedstuffs. Massey University, Palmerston North, New Zealand.
  20. Livesey, G., J. A. Wilkinson, M. Roe, R. Faulks, S. Clark, J. C. Brown, H. Kennedy and M. Elia. 1995. Influence of the physical form of barley grain on the digestion of its starch in the human small intestine and implications for health. Am. J. Clin. Nutr. 61:75-81.
  21. Seerley, R. W., W. L. Vandergrift and O. M. Hale. 1988. Effect of particle-size of wheat on performance of nursery, growing and finishing pigs. J. Anim. Sci. 66(10):2484-2489.
  22. Waghorn, G. C. 1986. Changes in rumen digesta of cows during a restricted feeding period when offered fresh red clover, lucerne or lucerne hay. New Zeal. J. Agric. Res. 29:223-241.
  23. Wondra, K. J., J. D. Hancock, K. C. Behnke and R. H. Hines. 1995a. Effects of dietary buffers on growth-performance, nutrient digestibility, and stomach morphology in finishing pigs. J. Anim. Sci. 73(2):414-420.
  24. Wondra, K. J., J. D. Hancock, K. C. Behnke, R. H. Hines and C. R. Stark. 1995b. Effects of particle-size and pelleting on growthperformance, nutrient digestibility, and stomach morphology in finishing pigs. J. Anim. Sci. 73(3):757-763.
  25. Wondra, K. J., J. D. Hancock, G. A. Kennedy, K. C. Behnke and K. R. Wondra. 1995d. Effects of reducing particle-size of corn in lactation diets on energy and nitrogen-metabolism in 2ndparity sows. J. Anim. Sci. 73(2):427-432.
  26. Wondra, K. J., J. D. Hancock, G. A. Kennedy, R. H. Hines and K. C. Behnke. 1995e. Reducing particle-size of corn in lactation diets from 1,200 to 400 micrometers improves sow and litter performance. J. Anim. Sci. 73(2):421-426.
  27. Wondra, K. J., J. D. Hancock, K. C. Behnke and C. R. Stark. 1995c. Effects of mill type and particle-size uniformity on growth-performance, nutrient digestibility, and stomach morphology in finishing pigs. J. Anim. Sci. 73(9):2564-2573.
  28. Wu, Y. U., V. Ravindran, D. G. Thomas, M. J. Birtles and W. H. Hendriks. 2004. Influence of phytase and xylanase, individually or in combination, on performance, apparent metabolisable energy, digestive tract measurements and gut morphology of broilers fed wheat-based diets containing adequate level of phosphorus. Br. Poult. Sci. 45:1-9.
  29. Robertson, J. B. and P. J. van Soest. 1981. The detergent system of analysis and its application to human foods. The Analysis of Dietary Fibre in Food. Marcel Dekker Incorporation, New York. pp. 123-158.
  30. SAS. 2003. SAS Institute, $SAS/STAT{\circledR}$ User's Guide: Statistics. Version 9.1. SAS Institute Inc., Cary, NC.
  31. Nielsen, E. K. and K. L. Ingvartsen. 2000. Effect of cereal type, disintegration method and pelleting on stomach content, weight and ulcers and performance in growing pigs. Lives. Prod. Sci. 66(3):271-282.
  32. Oryschak, M. A. and R.T. Zijlstra. 2002. Effect of dietary particle size and nutrient supply on energy digestibility and nitrogen excretion in ileal cannulated grower pigs. Can. J. Anim. Sci. 82(4):603-606.
  33. Kavanagh, N. 1994. Gastric ulcer in pigs. In Practice 16(4):209-213.
  34. Ayles, H. L., R. M. Frienship, G. A. Bubenik and R. O. Ball. 1999. Effect of feed particle size and dietary melatonin supplementation on gastric ulcers in swine. Can. J. Anim. Sci. 79:179-185.

Cited by

  1. Performance, gut morphology and carcass characteristics of fattening rabbits as affected by particle size of pelleted diets vol.64, pp.5, 2010,
  2. The influence of particle size and processing method for wheat-based diets, offered in dry or liquid form, on growth performance and diet digestibility in male weaner pigs vol.52, pp.10, 2012,
  3. Changes in pig diet particle size profile and nutrient content during on-farm storage and distribution to the feeders vol.68, pp.5, 2014,
  4. Different physical forms of one diet fed to growing pigs induce morphological changes in mandubular glands and local leptin (Ob) production and receptor (ObR) expression vol.100, pp.6, 2016,
  5. Protein structural changes during processing of vegetable feed ingredients used in swine diets: implications for nutritional value vol.29, pp.01, 2016,
  6. NONRUMINANT NUTRITION SYMPOSIUM: Controlling feed cost by including alternative ingredients into pig diets: A review1,2 vol.92, pp.4, 2014,
  7. The presence and distribution of cannabinoid type 1 and 2 receptors in the mandibular gland: The influence of different physical forms of diets on their expression in piglets vol.102, pp.2, 2017,