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Hristov AN, Bannink A, Crompton LA, Huhtanen P, Kreuzer M, McGee M, Nozière P, Reynolds CK, Bayat AR, Yáñez-Ruiz DR, Dijkstra J, Kebreab E, Schwarm A, Shingfield KJ, Yu Z. Invited review: Nitrogen in ruminant nutrition: A review of measurement techniques. J Dairy Sci 2019; 102:5811-5852. [PMID: 31030912 DOI: 10.3168/jds.2018-15829] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 02/27/2019] [Indexed: 01/17/2023]
Abstract
Nitrogen is a component of essential nutrients critical for the productivity of ruminants. If excreted in excess, N is also an important environmental pollutant contributing to acid deposition, eutrophication, human respiratory problems, and climate change. The complex microbial metabolic activity in the rumen and the effect on subsequent processes in the intestines and body tissues make the study of N metabolism in ruminants challenging compared with nonruminants. Therefore, using accurate and precise measurement techniques is imperative for obtaining reliable experimental results on N utilization by ruminants and evaluating the environmental impacts of N emission mitigation techniques. Changeover design experiments are as suitable as continuous ones for studying protein metabolism in ruminant animals, except when changes in body weight or carryover effects due to treatment are expected. Adaptation following a dietary change should be allowed for at least 2 (preferably 3) wk, and extended adaptation periods may be required if body pools can temporarily supply the nutrients studied. Dietary protein degradability in the rumen and intestines are feed characteristics determining the primary AA available to the host animal. They can be estimated using in situ, in vitro, or in vivo techniques with each having inherent advantages and disadvantages. Accurate, precise, and inexpensive laboratory assays for feed protein availability are still needed. Techniques used for direct determination of rumen microbial protein synthesis are laborious and expensive, and data variability can be unacceptably large; indirect approaches have not shown the level of accuracy required for widespread adoption. Techniques for studying postruminal digestion and absorption of nitrogenous compounds, urea recycling, and mammary AA metabolism are also laborious, expensive (especially the methods that use isotopes), and results can be variable, especially the methods based on measurements of digesta or blood flow. Volatile loss of N from feces and particularly urine can be substantial during collection, processing, and analysis of excreta, compromising the accuracy of measurements of total-tract N digestion and body N balance. In studying ruminant N metabolism, nutritionists should consider the longer term fate of manure N as well. Various techniques used to determine the effects of animal nutrition on total N, ammonia- or nitrous oxide-emitting potentials, as well as plant fertilizer value, of manure are available. Overall, methods to study ruminant N metabolism have been developed over 150 yr of animal nutrition research, but many of them are laborious and impractical for application on a large number of animals. The increasing environmental concerns associated with livestock production systems necessitate more accurate and reliable methods to determine manure N emissions in the context of feed composition and ruminant N metabolism.
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Affiliation(s)
- A N Hristov
- Department of Animal Science, The Pennsylvania State University, University Park 16802.
| | - A Bannink
- Wageningen Livestock Research, Wageningen University & Research, PO Box 338, 6700 AH Wageningen, the Netherlands
| | - L A Crompton
- School of Agriculture, Policy and Development, Centre for Dairy Research, University of Reading, PO Box 237 Earley Gate, Reading RG6 6AR, United Kingdom
| | - P Huhtanen
- Department of Agricultural Science, Swedish University of Agricultural Sciences, S-90, Umeå, Sweden
| | - M Kreuzer
- ETH Zurich, Institute of Agricultural Sciences, Universitaetstrasse 2, 8092 Zurich, Switzerland
| | - M McGee
- Teagasc, Animal & Grassland Research and Innovation Centre, Grange, Dunsany, Co. Meath, Ireland C15 PW93
| | - P Nozière
- Université Clermont Auvergne, INRA, VetAgro Sup, UMR Herbivores, F-63122 Saint-Genès-Champanelle, France
| | - C K Reynolds
- School of Agriculture, Policy and Development, Centre for Dairy Research, University of Reading, PO Box 237 Earley Gate, Reading RG6 6AR, United Kingdom
| | - A R Bayat
- Milk Production Solutions, Production Systems, Natural Resources Institute Finland (Luke), FI 31600 Jokioinen, Finland
| | - D R Yáñez-Ruiz
- Estación Experimental del Zaidín (CSIC), Profesor Albareda, 1, 18008, Granada, Spain
| | - J Dijkstra
- Animal Nutrition Group, Wageningen University & Research, PO Box 338, 6700 AH, Wageningen, the Netherlands
| | - E Kebreab
- Department of Animal Science, University of California, Davis 95616
| | - A Schwarm
- ETH Zurich, Institute of Agricultural Sciences, Universitaetstrasse 2, 8092 Zurich, Switzerland
| | - K J Shingfield
- Milk Production Solutions, Production Systems, Natural Resources Institute Finland (Luke), FI 31600 Jokioinen, Finland; Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3EB, United Kingdom
| | - Z Yu
- Department of Animal Sciences, The Ohio State University, Columbus 43210
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Dall-Orsoletta AC, Reiter T, Kozloski GV, Niderkorn V, Ribeiro-Filho HMN. Associative effects between Arachis pintoi and dwarf elephantgrass hays on nutritional value in sheep. ANIMAL PRODUCTION SCIENCE 2018. [DOI: 10.1071/an15864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aim of the present study was to evaluate the effect of including different levels of peanut (Arachis pintoi cv. Amarillo) hay (167 and 572 g/kg dry matter (DM) of crude protein and neutral detergent fibre respectively) on the nutritional value of diets based on dwarf elephantgrass (Pennisetum purpureum Shum, cv. Kurumi) hay (98 and 668 g/kg DM of crude protein and neutral detergent fibre respectively). Peanut hay was included in the proportions of 0.0, 0.33, 0.66 and 1.00 of total diet DM. Eight Texel × Suffolk crossbred wethers provided with duodenal cannula were assigned to the treatments in a replicated 4 × 4 Latin-square experiment. The organic matter (OM) intake increased linearly (P < 0.05) and the total apparent OM digestibility decreased linearly (P < 0.001) with an increasing inclusion of legume. The nitrogen (N) intake and N urinary excretion increased linearly (P < 0.05), whereas linear and quadratic responses were significant for digestible OM intake, N retention, and for the efficiency of rumen microbial protein synthesis. Cubic positive responses were significant (P < 0.05) for duodenal flow of total N, non-ammonia-N and rumen microbial-N. The inclusion of A. pintoi in dwarf elephantgrass-based diets improved the nutrient supply to sheep, but no additive effect was observed as a result of increasing the peanut proportion in the mixed diet.
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Kozloski GV, Stefanello CM, Oliveira L, Filho HMNR, Klopfenstein TJ. Technical note: Evaluation of urinary purine derivatives in comparison with duodenal purines for estimating rumen microbial protein supply in sheep. J Anim Sci 2017; 95:884-891. [PMID: 28380587 DOI: 10.2527/jas.2016.0840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A data set of individual observations was compiled from digestibility trials to examine the relationship between the duodenal purine bases (PB) flow and urinary purine derivatives (PD) excretion and the validity of different equations for estimating rumen microbial N (Nm) supply based on urinary PD in comparison with estimates based on duodenal PB. Trials (8 trials, = 185) were conducted with male sheep fitted with a duodenal T-type cannula, housed in metabolic cages, and fed forage alone or with supplements. The amount of PD excreted in urine was linearly related to the amount of PB flowing to the duodenum ( < 0.05). The intercept of the linear regression was 0.180 mmol/(d·kg), representing the endogenous excretion of PD, and the slope was lower than 1 ( < 0.05), indicating that only 0.43% of the PB in the duodenum was excreted as PD in urine. The Nm supply estimated by either approach was linearly related ( < 0.05) to the digestible OM intake. However, the Nm supply estimated through either of 3 published PD-based equations probably underestimated the Nm supply in sheep.
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