Effect of the Ratio of Non-fibrous Carbohydrates to Neutral Detergent Fiber and Protein Structure on Intake, Digestibility, Rumen Fermentation, and Nitrogen Metabolism in Lambs

  • Ma, T. ;
  • Tu, Y. ;
  • Zhang, N.F. ;
  • Deng, K.D. ;
  • Diao, Q.Y.
  • Received : 2015.01.08
  • Accepted : 2015.04.20
  • Published : 2015.10.01


This study aimed to investigate the effect of the ratio of non-fibrous carbohydrates to neutral detergent fibre (NFC/NDF) and undegraded dietary protein (UDP) on rumen fermentation and nitrogen metabolism in lambs. Four $Dorper{\times}thin-tailed$ Han crossbred lambs, averaging $62.3{\pm}1.9kg$ of body weight and 10 mo of age, were randomly assigned to four dietary treatments of combinations of two levels of NFC/NDF (1.0 and 1.7) and two levels of UDP (35% and 50% of crude protein [CP]). Duodenal nutrient flows were measured with dual markers of Yb and Co, and microbial N (MN) synthesis was estimated using $^{15}N$. High UDP decreased organic matter (OM) intake (p = 0.002) and CP intake (p = 0.005). Ruminal pH (p<0.001), ammonia nitrogen ($NH_3-N$; p = 0.008), and total volatile fatty acids (p<0.001) were affected by dietary NFC/NDF. The ruminal concentration of $NH_3-N$ was also affected by UDP (p<0.001). The duodenal flow of total MN (p = 0.007) was greater for lambs fed the high NFC/NDF diet. The amount of metabolisable N increased with increasing dietary NFC:NDF (p = 0.02) or UDP (p = 0.04). In conclusion, the diets with high NFC/NDF (1.7) and UDP (50% of CP) improved metabolisable N supply to lambs.


Non-fibrous Carbohydrate;Neutral Detergent Fibre;Undegraded Dietary Protein;Metabolisable N;Lambs


  1. Agle, M., A. N. Hristov, S. Zaman, C. Schneider, P. M. Ndegwa, and V. K. Vaddella. 2010. Effect of dietary concentrate on rumen fermentation, digestibility, and nitrogen losses in dairy cows. J. Dairy Sci. 93:4211-4222.
  2. Ahvenjarvi, S., A. Vanhatalo, and P. Huhtanen. 2002. Supplementing barley or rapeseed meal to dairy cows fed grass-red clover silage: I. Rumen degradability and microbial flow. J. Anim. Sci. 80:2176-2187.
  3. Allen, M. S. 2000. Effects of diet on short-term regulation of feed intake by lactating dairy cattle. J. Dairy Sci. 83:1598-1624.
  4. AOAC. 1990. Official Methods of Analysis. 15th edn. Assoc. Off. Agric. Chem., Washington, DC, USA.
  5. Asman, W. A. H., M. A. Sutton, and J. K. Schjorring. 1998. Ammonia: Emission, atmospheric transport and deposition. New Phytol. 139:27-48.
  6. Bailey, R. W. and J. C. MacRae. 1970. The hydrolysis by rumen and caecal microbial enzymes of hemicellulose in plant and digesta particles. J. Agric. Sci. 75:321-326.
  7. Bartram, C. G. 1987. The Endogenous Protein Content of Ruminant Proximal Duodenal Digesta. Ph.D. Thesis, University of Nottingham, Nottingham, UK.
  8. Cantalapiedra-Hijar, G., D. R. Yanez-Ruiz, A. I. Martin-Garcia, and E. Molina-Alcaide. 2009. Effects of forage: Concentrate ratio and forage type on apparent digestibility, ruminal fermentation, and microbial growth in goats. J. Anim. Sci. 87:622-631.
  9. Carro, M. D., C. Valdes, M. J. Ranilla, J. S. Gonzalez. 2000. Effect of forage to concentrate ratio in the diet on ruminal fermentation and digesta flow kinetics in sheep offered food at a fixed and restricted level of intake. Anim. Sci. 70:127-134.
  10. Cecava, M. J., N. R. Merchen, L. L. Berger, R. I. Mackie, and G. C. Fahey. 1991. Effects of dietary energy level and protein source on nutrient digestion and ruminal nitrogen metabolism in steers. J. Anim. Sci. 69:2230-2243.
  11. Chaney, A. L. and E. P. Marbach. 1962. Modified reagents for determination of urea and ammonia. Clin. Chem. 8:130-132.
  12. Clark, J. H., T. H. Klusmeyer, and M. R. Cameron. 1992. Microbial protein synthesis and flows of nitrogen fractions to the duodenum of dairy cows. J. Dairy Sci. 75:2304-2323.
  13. Egan, A. R. and R. J. Moir. 1965. Nutritional status and intake regulation in sheep: I. Effects of duodenally infused single doses of casein, urea, and propionate upon voluntary intake of a low-protein roughage by sheep. Crop Pasture Sci. 16:437-449.
  14. Goering, H. K. and P. J. Van Soest. 1970. Forage fiber analysis: (Apparatus, reagents, procedures, and some applications). In: Agricultural Handbook no. 379. Agricultural Research Service, US Department of Agriculture, Washington, DC, USA.
  15. Hall, M. B. 2000. Calculation of non-structural carbohydrate content of feeds that contain non-protein nitrogen. University of Florida (Bulletin 339), Gainesville, FL, USA. pp. A-25.
  16. Hoekstra, N. J., R. P. O. Schulte, P. C. Struik, and E. A. Lantinga. 2007. Pathways to improving the N efficiency of grazing bovines. Eur. J. Agron. 26:363-374.
  17. Hristov, A. N., J. K. Ropp, K. L. Grandeen, S. Abedi, R. P. Etter, A. Melgar, and A. E. Foley. 2005. Effect of carbohydrate source on ammonia utilization in lactating dairy cows. J. Anim. Sci. 83:408-421.
  18. Kiran, D. and T. Mutsvangwa. 2007. Effects of barley grain processing and dietary ruminally degradable protein on urea nitrogen recycling and nitrogen metabolism in growing lambs. J. Anim. Sci. 85:3391-3399.
  19. Lord, E. I. 1996. Pilot nitrate sensitive area scheme: Report of the first 4 years. In: Diffuse Pollution and Agriculture (Eds. Petchey, A. M., B. J. D'Arcy, and C. A. Frost). The Scottish Agricultural College, Aberdeen, UK. pp. 64-72.
  20. Ma, T., K. D. Deng, C. G. Jiang, Y. Tu, N. F. Zhang, J. Liu, Y. G. Zhao, and Q. Y. Diao. 2013. The relationship between microbial N synthesis and urinary excretion of purine derivatives in Dorper $\times$ thin-tailed Han crossbred sheep. Small Rumin. Res. 112:49-55.
  21. Ma, T., K. D. Deng, Y. Tu, N. F. Zhang, C. G. Jiang, J. Liu, Y. G. Zhao, and Q. Y. Diao. 2014. Effect of dietary forage-toconcentrate ratios on urinary excretion of purine derivatives and microbial nitrogen yields in the rumen of Dorper crossbred sheep. Livest. Sci. 160:37-44.
  22. Mould, F. L. and E. R. Orskov. 1983. Manipulation of rumen fluid pH and its influence on cellulolysis in sacco, dry matter degradation and the rumen microflora of sheep offered either hay or concentrate. Anim. Feed Sci. Technol. 10:1-14.
  23. Mould, F. L., E. R. Orskov, and S. O. Mann. 1983. Associative effects of mixed feeds: I. Effects of type and level of supplementation and the influence of the rumen fluid pH on cellulolysis in vivo and dry matter digestion of various roughages. Anim. Feed Sci. Technol. 10:15-30.
  24. National Research Council. 2007. Nutrient requirements of small ruminants: Sheep, goats, cervids, and new world camelids. National Academies Press, Washington, DC, USA.
  25. Pina, D. S., S. C. Valadares Filho, L. O. Tedeschi, A. M. Barbosa, and R. F. D. Valadares. 2009. Influence of different levels of concentrate and ruminally undegraded protein on digestive variables in beef heifers. J. Anim. Sci. 87:1058-1067.
  26. Ramos, S., M. L. Tejido, M. E. Martinez, M. J. Ranilla, and M. D. Carro. 2009. Microbial protein synthesis, ruminal digestion, microbial populations, and nitrogen balance in sheep fed diets varying in forage-to-concentrate ratio and type of forage. J. Anim. Sci. 87:2924-2934.
  27. Reynal, S. M. and G. A. Broderick. 2005. Effect of dietary level of rumen-degraded protein on production and nitrogen metabolism in lactating dairy cows. J. Dairy Sci. 88:4045-4064.
  28. Stern, M. D., G. A. Varga, J. H. Clark, J. L. Firkins, J. T. Huber, and D. L. Palmquist. 1994. Evaluation of chemical and physical properties of feeds that affect protein metabolism in the rumen. J. Dairy Sci. 77:2762-2786.
  29. Van Soest, P. J., J. B. Robertson, and B. A. Lewis. 1991. Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74:3583-3597.
  30. Volden, H. and O. M. Harstad. 1995. Effect of rumen incubation on the true indigestibility of feed protein in the digestive tract determined by nylon bag techniques. Acta Agric. Scand. A-AN. 45:106-115.

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