scholarly journals Contribution of rumen protozoa to duodenal flow of nitrogen, conjugated linoleic acid and vaccenic acid in steers fed silages differing in their water-soluble carbohydrate content

2006 ◽  
Vol 96 (5) ◽  
pp. 861-869 ◽  
Author(s):  
David R. Yáñez-Ruiz ◽  
Nigel D. Scollan ◽  
Roger J. Merry ◽  
Charles J. Newbold

The present experiment was designed to estimate the quantitative contribution of rumen protozoa to the total N, conjugated linoleic acid (CLA) and vaccenic acid (VA;trans-11–18:1) flow to the duodenum of steers fed two silage diets: control silage (CS) and silage high in water-soluble carbohydrates (HS). Protozoal duodenal flows were estimated using a real-time PCR assay to quantify the genes encoding protozoal 18S ribosomal RNA. Denaturing gradient gel electrophoresis was used to confirm that the rumen protozoa populations were similar to the protozoal population flowing to the duodenum. Estimated duodenal flow of protozoal N was 14·2 and 18·2 g/d (P>0·05) for animals fed the CS and HS diets respectively. Protozoal flow thus represented between 12 and 15 % of the total N duodenal flow. In terms of fatty acid flow, protozoa accounted for between 30 and 43 % of the CLA and 40 % of the VA reaching the duodenum. The contribution of protozoa to 16:0 and 18:0 flows to the duodenum was less than 20 and 10 %, respectively. These results show that the fatty acids within protozoa make up a significant proportion of the CLA and VA reaching the duodenum of ruminants.

1999 ◽  
Vol 69 (1) ◽  
pp. 143-146 ◽  
Author(s):  
M. Enser ◽  
N. D. Scollan ◽  
N. J. Choi ◽  
E. Kurt ◽  
K. Hallett ◽  
...  

AbstractWe have examined the effect of dietary fats containing n-3 polyunsaturated fatty acids on the conjugated linoleic acid (CLA) content of beef m. longissimus lumborum. Four groups of eight Charolais steers were given, for 120 days, grass silage plus a barley/sugar-beet feed concentrate containing one of four fat supplements: Megalac (saturated), linseed (high 18: 3),fish oil (high 20: 5 n-3, eicosapentenoic acid and 22: 6 n-3, docosahexaenoic acid) or linseed plus fish oil. The concentrates supplied 400 g/kg dry-matter (DM) intake and were designed to supply 45 g/kg of the total dietary fat calculated to be 60 g/kg of DM and to contain similar amounts of linoleic acid. Muscle from steers given the Megalac supplement contained 11·3 mg CLA per 100 g muscle and this was increased two- to three-fold in animals given the more unsaturated fat supplements. The increased deposition of CLA was similar for both linseed and fish oil supplements although the concentrations of total n-3 polyunsaturated fatty acids in the fish oil diet were much less than in the linseed diet. This suggests potent inhibition of conversion of CLA to trans vaccenic acid by fish oil fatty acids or their rumen metabolites.


2006 ◽  
Vol 136 (4) ◽  
pp. 992-997 ◽  
Author(s):  
Marianne Raff ◽  
Tine Tholstrup ◽  
Kristen Sejrsen ◽  
Ellen M. Straarup ◽  
Niels Wiinberg

1966 ◽  
Vol 66 (3) ◽  
pp. 351-357 ◽  
Author(s):  
W. Ellis Davies ◽  
G. ap Griffith ◽  
A. Ellington

The primary growth of eight varieties of three species–white clover (3), red clover (4) and lucerne (1)–was sampled at fortnightly intervals and the percentage dry matter, in vitro digestibility, crude protein, water soluble carbohydrates, P, Ca, K, Na and Mg were determined.Differences between species were nearly always significant and the general order of merit was white clover, red clover and lucerne. The exceptions were for dry-matter percentage where this order was reversed, and red clover had the lowest Na and highest Mg content.


2019 ◽  
Vol 17 (4) ◽  
pp. 539-544
Author(s):  
Md Juiceball Hassan ◽  
Md Masudul Karim ◽  
Md Amirul Islam ◽  
Md Habibur Rahman Pramanik ◽  
Md Alamgir Hossain

Submergence stress at early vegetative stage is one of the most important constraints in the productivity of rice in Bangladesh. Submergence causes yield loss of rice at Aman season in Bangladesh and therefore, it is necessary to develop submergence tolerant rice cultivars. A pot experiment was conducted at the net house of Department of Crop Botany, Bangladesh Agricultural University, during Aman season from July to December, 2017 to evaluate the changes in root porosity and water soluble carbohydrates (WSCs) associated with submergence tolerance in rice. The experiment consisted of two factors—(i) Rice cultivars (Binadhan-11, Binadhan-12, BRRI dhan51 and BRRI dhan52 as tolerant and BRRI dhan49 as susceptible) and(ii) Submergence stress: Submergence for 14 days at vegetative stage and control. Submergence stress was imposed by dipping of pots into a water tank with about 90 cm depth of water while the control plants are maintained in the pot house of the field laboratory. The plants were sampled at seven days interval during submergence to determine the changes in root porosity and to examine the contribution of shoot reserves for their survival. The root porosity was measured by pycnometer method and water soluble carbohydrate was measured by the anthrone method. Tolerant cultivars showed greater root porosity development in both control and stress condition but the susceptible cultivar showed significantly lower root development in stress condition. Higher root porosity might help tolerant cultivars to survive in submergence stress more efficiently. Tolerant rice cultivars had high initial soluble carbohydrate than the susceptible one. Under submergedcondition, the tolerant cultivars showed slow depletion of water soluble carbohydrate compared to susceptible cultivar. Higher carbohydrate contents in tolerant cultivars might act as buffer stock during submergence for their better survival and growth. J Bangladesh Agril Univ 17(4): 539–544, 2019


2014 ◽  
Vol 54 (12) ◽  
pp. 1971 ◽  
Author(s):  
P. C. Beukes ◽  
P. Gregorini ◽  
A. J. Romera ◽  
S. L. Woodward ◽  
E. N. Khaembah ◽  
...  

The largest contributor to nitrogen (N) leaching from ryegrass-clover pasture based dairy farms is the surplus feed N excreted as urinary N (UN) onto pastures. Pastures consisting of mixtures of ryegrass, herbs and legumes (diverse pastures) have shown potential to yield similar DM, but with a lower N content and a higher water soluble carbohydrate : crude protein ratio compared with standard ryegrass–clover pastures. These diverse pastures have shown the potential to lower the UN excreted by dairy cows in short-term, late-lactation studies. This modelling study was designed to scale the results from component studies up to farm and over a full season to evaluate the potential of diverse pastures to become a suitable strategy for reducing N leaching on New Zealand dairy farms. The Molly cow model was tested against observed data from one indoor and one outdoor study where feeding diverse pasture resulted in UN (N excreted in urine g/day) reductions of 50% and 17%, respectively. The model predicted UN reductions of 23% and 17%. Farm-scale model scenarios, where 20% or 50% of the farm was sown with diverse pastures, resulted in 2% and 6% reductions in UN deposited onto paddocks. This reduction was smaller than expected with some system interactions related to seasonal feed supply, diet composition and total N intake being likely to play a role. The reduction in UN onto paddocks, together with a dilution effect from larger urine volumes per cow per day as a result of lower DM% of diverse pastures, resulted in N leaching reductions of 11% and 19% for the two scenarios, respectively. This potential to reduce N leaching needs to be evaluated further in the context of farm profitability when other aspects of diverse pastures such as yield, persistency, drought resistance and ability to extract N from the soil becomes part of the farm-system analysis.


2005 ◽  
Vol 81 (3) ◽  
pp. 431-436 ◽  
Author(s):  
M. A. Valvo ◽  
M. Lanza ◽  
M. Bella ◽  
V. Fasone ◽  
M. Scerra ◽  
...  

AbstractTwenty pregnant Comisana ewes were divided into two groups of 10. One group was allowed to graze a vetch pasture (grass). The second group of animals was housed collectively in a pen and was given hay and concentrates (concentrate). After lambing, all the ewes were allowed to stay with the respective lambs between 18:00 h and 07:00 h of the following day in two different pens. Therefore all the lambs were raised exclusively on maternal milk. The lambs were slaughtered at 38 days of age. Milk and lamb meat (longissimus dorsi muscle) fatty acids were analysed. Ewes on grass produced milk with a lower (P < 0·001) proportion of saturated fatty acids and with a higher proportion of both monounsaturated (P < 0·05) and polyunsaturated fatty acids (P < 0·01) than ewes given concentrates. Trans-vaccenic acid was significantly higher (P < 0·001) in milk from grass-fed animals compared with ewes given concentrates. Linoleic acid (C18: 2 n-6) tended to be higher (P = 0·06) in milk from ewes on concentrates while linolenic acid (C18: 3 n-3) was significantly higher (P < 0·001) in milk from animals grazing pasture. Conjugated linoleic acid (cis-9, trans-11 C18: 2) was almost double in milk from grass-fed ewes compared with animals given concentrates (P < 0·001). Regarding lamb tissue, trans-vaccenic acid (C18: 1 trans-11) was higher (P = 0·01) in the fat from lambs raised by grazing ewes. Linoleic acid (C18: 2 n-6) was at higher concentration (P < 0·001) in the fat from lambs raised by ewes given concentrates. Linolenic acid (C18: 3 n-3) was increased three-fold (P < 0·001) in the fat of lambs from the grass group compared with lambs suckled by ewes given concentrates. The isomer cis-9, trans-11 of conjugated linoleic acid was present at double concentration (P < 0·001) in the fat from animals raised by grazing ewes. Eicosapentaenoic (C20: 5 n-3; EPA) and docosaesaenoic (C22: 6 n-3; DHA) acids were higher (respectively P < 0·001 and P = 0·01) in the intramuscular fat from lambs from the grass group compared with animals from the concentrate group. The n-6/n-3 ratio was lower (P < 0·001) in the meat from lambs raised by grazing ewes. Overall this trial showed that ewe feeding system strongly affects intramuscular fatty acids even in lambs raised exclusively on maternal milk.


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