+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Levels of total nitrogen and total volatile fatty acids in the rumen fluid of sheep under different grazing management systems

, : Levels of total nitrogen and total volatile fatty acids in the rumen fluid of sheep under different grazing management systems. Aust J Exp Agr Anim Husb 7(28): 434-440

Concentrations of total N and total volatile fatty acids (VFA) in the rumen fluid of sheep grazing improved pastures were measured for 10 months in a dry year on the southern tableland of New South Wales, and the concentrations of N and VFA were related to season, wool production, and grazing management. The observations were made during 2 long-term grazing management experiments. In the 1st experiment 4 groups of breeding Merino ewes grazed a Wimmera ryegrass-subterranean clover (Lolium rigidum Gaud.-Trifolium sub-terraneum Lpasture. A deferred grazing system (autumn saving) of pasture management was compared with continuous grazing at stocking rate treatments equivalent to 7.0 and 3.5 ewes to the acre. In the 2nd experiment 2 groups of Merino weaners grazed a Phalaris tuberosa-subterranean clover pasture at a stocking rate equivalent to 8.6 sheep to the acre. One group received a hay supplement, the other did not. In both experiments N values were low between late autumn and mid-winter and again between late spring and summer, and high in early autumn and again in spring (P< 0.05). The low levels were about 55% of peak autumn and spring levels in (experiment 1) and 60% of peak autumn and spring levels in (experiment 2). Total VFA did not vary significantly between seasons in either experiment. At the higher stocking rate the ewes had lower levels of rumen total N than at the lower stocking rate. VFA did not vary consistently between stocking rates. At both stocking rates ewes on the autumn saving system of grazing management had more N in the rumen fluid during late pregnancy and early lactation than did those on the continuous grazing system (P< 0.001). After the ewes had access to the saved pasture, autumn saving resulted in a higher concentration of VFA than continuous grazing (P> 0.05). Although feeding a hay supplement benefited the weaners the concentrations of total N in the rumen fluid of the 2 groups of sheep were similar. There was a fairly consistent tendency for the group receiving hay to have lower concentrations of VFA in their rumen fluid. Possible reasons for these effects are discussed.


Other references

Tilden, V., 1985: Development and use of computer managed instruction. Computers in Nursing 3(5): 207-211

Lebedeva, I.V.; Kudrin, V.S.; Balitskaya, N.V., 1997: Comprehensive assessment of the labor of laboratory physicians of clinical diagnostic laboratories at therapeutic and prophylactic institutions. Presents a system of quantitative criteria for comprehensive assessment of the labor of laboratory physicians based on the results of a comparative quantitative analysis of the actual labor, standards, and mean values. The labor of a laboratory ph...

Brownell, K.D.; Hayes, S.C.; Barlow, D.H., 1977: Patterns of appropriate and deviant sexual arousal: the behavioral treatment of multiple sexual deviations. Journal of Consulting and Clinical Psychology 45(6): 1144-1155

Saragih, B., 1995: Indonesian coffee: performance, problems and prospects. Important features relating to the biology, agronomy, production practices and postharvest handling of coffee in Indonesia are explored in order to shed light on the problems within the sector. The focus is on robusta coffee, the major coffee prod...

Vigh, J.; Rapp, K.; Lasater, E.M., 2002: Caffeine Inhibits GABA- and Gly-evoked Chloride Currents Via Different Mechanisms in Wide Field Amacrine Cells. Purpose: To determine whether inhibitory amino acid evoked currents (GABA and Gly) of wide field amacrine cells (WFACs) are modulated by intracellular Ca++ release by caffeine. Methods: Isolated WFACs from white bass retina were recorded from usin...

Dubey, J.P., 1977: Toxoplasma, Hammondia, Besnoitia, Sarcocystis, and other tissue cyst-forming Coccidia of man and animals. Toxoplasma, Hammondia, Sarcocystis, Frenkelia, Besnoitia, Isospora and Levineia n.g. are reviewed with over 18 pages of references. H. heydorni n. comb. for I. heydorni is temporarily placed in Hammondia because of structural and life-cycle simila...

Saito, H.; Goovaerts, P., 2003: Selective Remediation of Contaminated Sites Using a Two-Level Multiphase Strategy and Geostatistics. Selective soil remediation aims to reduce costs by cleaning only the fraction of an exposure unit (EU) necessary to lower the average concentration below the regulatory threshold. This approach requires a prior stratification of each EU into small...

Harman, D.M.; Brown, M.L., 1974: Leader and bark characteristics in different growth categories of White Pine (Pinus strobus L. and Pinus monticola Dougl.) in Maryland. A study made to elucidate leader characteristics of possible relevance to attack by Pissodes strobi [cf. FA 33, 6621]. Dimensional and chemical characteristics of leaders and bark were examined in tall trees (40-75 ft), and smaller trees (12-25 ft...

Sauka-Spengler, T.; Bronner, M., 2010: Snapshot: neural crest. Cell 143(3): 486-486.E1

BErland, L., 1947: Croisiere du Bougainville aus ils australes franYaises (2e Fascicule). XVI. Araignees. Araignees Mem Mus nat Hist nat Paris NS: 201: 53-64