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The effects of dietary nitrogen to water-soluble carbohydrate ratio on isotopic fractionation and partitioning of nitrogen in non-lactating sheep

Published online by Cambridge University Press:  18 March 2013

L. Cheng*
Affiliation:
Faculty of Agriculture & Life Science, Lincoln University, PO Box 84, New Zealand
A. M. Nicol
Affiliation:
Faculty of Agriculture & Life Science, Lincoln University, PO Box 84, New Zealand
R. J. Dewhurst
Affiliation:
Teagasc, Animal & Grassland Research and Innovation Centre, Grange, Dunsany, County Meath, Ireland
G. R. Edwards
Affiliation:
Faculty of Agriculture & Life Science, Lincoln University, PO Box 84, New Zealand
*
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Abstract

The main objective of this study was to investigate the relationship between partitioning and isotopic fractionation of nitrogen (N) in sheep consuming diets with varying ratios of N to water-soluble carbohydrate (WSC). Six non-lactating sheep were offered a constant dry matter (DM) allowance with one of three ratios of dietary N/WSC, achieved by adding sucrose and urea to lucerne pellets. A replicated 3 dietary treatments (Low, Medium and High N/WSC) × 3 (collection periods) and a Latin square design was used, with two sheep assigned to each treatment in each period. Feed, faeces, urine, plasma, wool, muscle and liver samples were collected and analysed for 15N concentration. Nitrogen intake and outputs in faeces and urine were measured for each sheep using 6-day total collections. Blood urea N (BUN) and urinary excretion of purine derivative were also measured. Treatment effects were tested using general ANOVA; the relationships between measured variables were analysed by linear regression. BUN and N intake increased by 46% and 35%, respectively, when N/WSC increased 2.5-fold. However, no indication of change in microbial protein synthesis was detected. Results indicated effects of dietary treatments on urinary N/faecal N, faecal N/N intake and retained N/N intake. In addition, the linear relationships between plasma δ15N and urinary N/N intake and muscle δ15N and retained N/N intake based on individual measurements showed the potential of using N isotopic fractionation as an easy-to-use indicator of N partitioning when N supply exceeds that required to match energy supply in the diet.

Type
Nutrition
Copyright
Copyright © The Animal Consortium 2013 

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References

Brand, TS, Frank, F, Cloete, SWP 1992. Substitution of lucerne hay by untreated, urea-enriched and urea-ammoniated wheat straw in diets for sheep. South African Journal of Animal Science 22, 185193.Google Scholar
Broderick, GA, Clayton, MK 1997. A statistical evaluation of animal and nutritional factors influencing concentrations of milk urea nitrogen. Journal of Dairy Science 80, 29642971.Google Scholar
Brookes, IM, Nicol, AM 2007. The protein requirements of grazing livestock. In Pasture and supplements for grazing animals (ed. PV Rattray, IM Brookes and AM Nicol), pp. 173188. New Zealand Society of Animal Production Occasional Publication No 14, Hamilton, New Zealand.Google Scholar
Burke, JL, Pacheco, D, Cosgrove, GP 2011. In vitro digestion of ryegrasses harvested in the morning and afternoon to manipulate water soluble carbohydrate concentrations. Proceedings of the New Zealand Society of Animal Production 71, pp. 229–233.Google Scholar
Castillo, AR, Kebreab, E, Beever, DE, Barbi, JH, Sutton, JD, Kirby, HC, France, J 2001. The effect of protein supplementation on nitrogen utilization in lactating dairy cows. Journal of Animal Science 79, 247253.CrossRefGoogle ScholarPubMed
Cheng, L, Kim, EJ, Merry, RJ, Dewhurst, RJ 2011. Nitrogen partitioning and isotopic fractionation in dairy cows consuming diets based on a range of contrasting forages. Journal of Dairy Science 94, 20312041.Google Scholar
Clarke, T, Flinn, PC, McGowan, AA 1982. Low-cost pepsin-cellulase assays for prediction of digestibility of herbage. Grass and Forage Science 37, 147150.Google Scholar
Edwards, GR, Parsons, AJ, Rasmussen, S 2007. Higher sugar ryegrasses for dairy systems. In Meeting the challenges for pasture-based dairying (ed. DF Chapman, DA Clark, KL Macmillan, DP Nation), pp. 307–334. Proceedings of the Australasian Dairy Science Symposium, Melbourne, Australia.Google Scholar
George, SK, Dipu, MT, Mehra, UR, Singh, P, Verma, AK, Rangaokar, JS 2006. Improved HPLC method for the simultaneous determination of allantoin, uric acid and creatinine in cattle urine. Journal of Chromatography 832, 134137.Google Scholar
Hilderbrand, GV, Varley, SD, Robbins, CT, Hanley, TA, Titus, K, Servheen, C 1996. Use of stable isotopes to determine diets of living and extinct bears. Canadian Journal of Zoology 74, 20802088.Google Scholar
Hobson, KA, Alisauskas, RT, Clark, RG 1993. Stable-nitrogen isotope enrichment in avian tissues due to fasting and nutritional stress: implications for isotopic analyses of diet. The Cooper Ornithological Society 95, 388394.Google Scholar
Kohn, RA, Dinneen, M, Russek-Cohen, E 2005. Using blood urea nitrogen to predict nitrogen excretion and efficiency of nitrogen utilization in cattle, sheep, goats, horses, pigs, and rats. Journal of Animal Science 83, 879889.Google Scholar
Koyama, M 1985. Fractionation of nitrogen isotopes by domestic animals. Japanese Journal of Zootechnical Science 56, 361362.Google Scholar
Litherland, AJ, Lambert, MG 2007. Factors affecting the quality of pastures and supplements produced on farms. In Pasture and supplements for grazing animals (ed. PV Rattray, IM Brookes and AM Nicol), pp. 8195. New Zealand Society of Animal Production Occasional Publication No 14, Hamilton, New Zealand.Google Scholar
MacRae, JC, Walker, A, Brown, D, Lobley, GE 1993. Accretion of total and individual amino acids by organs and tissues of growing lambs and the ability of nitrogen balance techniques to quantitate protein retention. Animal Production 57, 237245.Google Scholar
Macko, SA, Fogel, ML, Engel, MH, Hare, PE 1986. Kinetic fractionation of stable nitrogen isotopes during amino acid transamination. Geochim Cosmochim Acta 50, 21432146.Google Scholar
Männel, T, Auerswald, TK, Schnyder, H 2007. Altitudinal gradients of grassland carbon and nitrogen isotope composition are recorded in the hair of grazers. Global Ecology and Biogeography 16, 583592.Google Scholar
Miller-Graber, PA, Lawrence, LM, Foreman, JH, Bump, KD, Fisher, MG, Kurcz, EV 1991. Dietary protein level and energy metabolism during treadmill exercise in horses. Journal of Nutrition 121, 14621469.CrossRefGoogle ScholarPubMed
Miller, LA, Moorby, JM, Davies, DR, Humphreys, MO, Scollan, ND, MacRae, JC 2001. Increased concentration of water soluble carbohydrate in perennial ryegrass (Lolium perenne L.): Milk production from late-lactation dairy cows. Grass and Forage Science 56, 383394.Google Scholar
Moorby, JM, Evans, RT, Scollan, ND, MacRae, JC, Theodorou, MT 2006. Increased concentration of water-soluble carbohydrate in perennial ryegrass (Lolium perenne L.): Evaluation in dairy cows in early lactation. Grass and Forage Science 61, 5259.Google Scholar
Nicol, AM, Brookes, IM 2007. The metabolisable energy requirements of grazing livestock. In Pasture and supplements for grazing animals (ed. PV Rattray, IM Brookes and AM Nicol), pp. 151173. New Zealand Society of Animal Production Occasional Publication No 14, Hamilton, New Zealand.Google Scholar
Pacheco, D, Lane, GA, Burke, JL, Cosgrove, GP 2007. Water soluble carbohydrates relative to protein in fresh forage: impact on efficiency of nitrogen utilization in lactating dairy cows. Journal of Animal Science 85, 431432.Google Scholar
Rasmussen, S, Parsons, AJ, Bassett, S, Christensen, MJ, Hume, DE, Johnson, LJ, Johnson, RD, Simpson, WR, Stacke, C, Voisey, CR, Xue, H, Newman, JA 2007. High nitrogen supply and carbohydrate content reduce fungal endophyte and alkaloid concentration in Lolium perenne. New Phytologist 173, 787797.Google Scholar
Reynolds, CK, Kristensen, NB 2008. Nitrogen recycling through the gut and the nitrogen economy of ruminants: an asynchronous symbiosis. Journal of Animal Science 86 (E suppl.), E293E305.Google Scholar
Rogers, GE, Schlink, AC 2010. Wool growth and production. In International sheep and wool handbook (ed. DJ Cottle), pp. 373394. Nottingham University Press, Christchurch, New Zealand.Google Scholar
Sick, H, Roos, N, Saggau, E, Haas, K, Meyn, V, Walch, B, Trugo, N 1997. Amino acid utilization and isotope discrimination of amino nitrogen in nitrogen metabolism in rat liver in vivo. Zeitschrift für Ernahrungswissenschaft 36, 340346.CrossRefGoogle ScholarPubMed
Sponheimer, M, Robinson, T, Ayliffe, L, Roeder, B, Hammer, J, Passey, B, West, A, Cerling, T, Dearing, D, Ehleringer, J 2003. Nitrogen isotopes in mammalian herbivores: hairδ 15N values from a controlled feeding study. International Journal of Osteoarchaeology 13, 8087.Google Scholar
Steele, KW, Bonish, PM, Daniel, RM, O'Hara, GW 1983. Effect of rhizobial strain and host plant on nitrogen isotopic fractionation in legumes. Plant Physiology 72, 10011004.Google Scholar
Steele, KW, Daniel, RM 1978. Fractionation of nitrogen isotopes by animals: further complication to the use of variations in the natural abundance of 15N for tracer studies. Journal of Agricultural Science 90, 79.Google Scholar
van Vuuren, AM, van der Koelen, CJ, Valk, H, de Visser, H 1993. Effects of partial replacement of ryegrass by low protein feeds on rumen fermentation and nitrogen loss by dairy cows. Journal of Dairy Science 76, 29822993.Google Scholar
Varel, VH, Nienaber, JA, Freetly, HC 1999. Conservation of nitrogen in cattle feedlot waste with urease inhibitors. Journal of Animal Science 77, 11621168.Google Scholar
Wattiaux, MA, Reed, JD 1995. Fractionation of nitrogen isotopes by mixed ruminal bacteria. Journal of Animal Science 73, 257266.Google Scholar