Using a complex non-TDN based model (the DVE/OEB system) to predict microbial protein synthesis, endogenous protein, degradation balance, and total truly absorbed protein supply of different varieties of cereal oats for ruminants

2009 ◽  
Vol 80 (3) ◽  
pp. 273-279 ◽  
Author(s):  
Peiqiang YU ◽  
Zhiyuan NIU
2015 ◽  
Vol 15 (2) ◽  
pp. 289-305 ◽  
Author(s):  
Maja Fijałkowska ◽  
Barbara Pysera ◽  
Krzysztof Lipiński ◽  
Danuta Strusińska

Abstract Losses of crude protein during ensiling of herbages, in contrast to carbohydrates, do not affect the reduction of its content; their form is changed into greater solubility non-protein compounds and also highly degraded forms, which lower the efficiency of the microbial protein synthesis in the rumen. These processes are accompanied by a change of amino acid composition of herbage protein and decrease in intestinal digestibility of protein from feeds as a result of the formation of indigestible complexes with carbohydrates (ADIN). Reduction of protein degradation in silages is achieved by accelerated acidity through addition of acids or dominance of homofermentative bacteria. The positive effects of fermentation inhibitors or sorbents use, as well as the wilting of raw material on the level and rate of protein degradation were demonstrated by many researchers. A greater contribution of protein nitrogen and reduction of deamination in silages can also be obtained by using bacteria inoculants. Increasing the proportion of protein nitrogen is accompanied by the improved efficiency of microbial protein synthesis.


2007 ◽  
Vol 2007 ◽  
pp. 216-216
Author(s):  
Yashar Vakil Faraji ◽  
Mojtaba Zahedifar ◽  
Jafari Khorshidi Kaveh

Rumen microbes are rich in nucleic acid: around 18% of total nitrogen is present on nucleic acids or 11% in purines. Rumen microbes constitue the major source of protein supply to the ruminant. The purines from the rumen microbes are metabolized and excreted in the urine as their end products: hypoxanthine, xanthine, uric acid and allantoin. In buffalo and cattle because of high xanthine oxidase activity in intestine and blood, hypoxanthine and xanthine convert to uric acid therefore only uric acid and allantoin excreted in urine way (Chen, X. B., Ørskov, E. R., 2003). This research carried out to use excretion of purine derivatives namely allantoin and uric acid as a parameter to estimate the microbial protein synthesis in the rumen of native swamp buffalo in north of iran, Mazandaran Province.


2000 ◽  
Vol 71 (2) ◽  
pp. 369-379 ◽  
Author(s):  
R. G. Wilkinson ◽  
L. A. Sinclair ◽  
J. Powles ◽  
C. M. Minter

AbstractThe response of lactating ewes grazing grass to variations in effective rumen degradable protein (ERDP) and digestible undegradable protein (DUP) supply from concentrates was investigated. During the spring and early summer of 1993, 36 Friesland and 12 Finn Dorset ewes were offered continuous access to permanent pasture (Lolium perenne) and allocated to one of six concentrates (1·2 kg/day) formulated to be iso-energetic and to supply 149 (H), 126 (M) or 103 (L) g ERDP and 70 (A) or 45 (B) g DUP per kg dry matter (DM) in a 3 ✕ 2 factorial design. Herbage intake was estimated using the n-alkane technique and herbage samples obtained for analysis. Ewe milk yields, milk composition, live weights (LW) and condition scores (CS) were recorded weekly. The DM and nitrogen degradability characteristics of the grass samples and concentrates were determined using four Friesland wether lambs fitted with permanent rumen cannulae. Throughout the experiment the grass ERDP: FME ratio was lower than the optimum for maximal microbial protein synthesis. However, using a rumen solid phase outflow rate of 0·05 per h, estimated concentrate ERDP and DUP supplies were similar to those predicted. Increasing concentrate ERDP supply had no effect on herbage intake or LW and CS change but reduced milk fat concentration (P < 0·05) and increased milk lactose concentration (P < 0·05) and the yields of milk (P < 0·01), protein (P < 0·05) and lactose (P < 0·01). There were no significant effects of concentrate DUP supply. In conclusion, it is suggested that concentrate ERDP increased microbial protein synthesis and metabolizable protein supply, a proportion of which may have been deaminated to provide precursors for milk lactose synthesis, such that the marginal response in milk protein yield was 0·210.


1981 ◽  
Vol 29 (4) ◽  
pp. 273-283
Author(s):  
S. Tamminga

The effect of different roughage:concentrate ratios on N entering the small intestine was studied in groups of 2 to 5 cows with a rumen fistula and re-entrant cannulae at the beginning of the small intestine. In 3 series there were 10 treatments in which DM intake ranged between 3.8 and 15.7 kg daily; the proportion of long roughage in the diet was from 29 to 81%. The apparent digestibility of organic matter (O), crude fibre (XF) and nitrogen-free extracts (XX) was 76, 69 and 81%, respectively. The proportion of the digestion taking place in the stomach was 59, 94 and 76%. A larger proportion of the apparently digestible organic matter tended to be digested in the stomach when there was a larger proportion of long roughage in the diet. The contribution of microbial N to the intestinal N was estimated. From this the efficiency of microbial protein synthesis was estimated and related to the amount of carbohydrates (XF + XX) fermented in the stomach. Per kg carbohydrates fermented, 32 plus or minus 1.5 g microbial N was produced. The percentage of dietary N not degraded in the stomach averaged 30 plus or minus 1.5. Varying the ratio between long roughage and pelleted concentrates seemed to have little effect on the degradation of dietary protein or on the efficiency of microbial protein synthesis. With long roughage in the diet between 29 and 81% there seems little effect of varying the roughage:concentrate ratio on the protein supply in dairy cows. (Abstract retrieved from CAB Abstracts by CABI’s permission)


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