scholarly journals Lipid metabolism in mixtures of red clover (Trifolium repens) and perennial ryegrass (Lolium perenne) in lab scale silages and in vitro rumen incubations

animal ◽  
2013 ◽  
Vol 7 (9) ◽  
pp. 1454-1463 ◽  
Author(s):  
G. Van Ranst ◽  
M. Vandewalle ◽  
F. Gadeyne ◽  
J. De Riek ◽  
V. Fievez
1999 ◽  
Vol 82 (2) ◽  
pp. 139-147 ◽  
Author(s):  
M. Reverter ◽  
T. Lundh ◽  
J. E. Lindberg

Two experiments were performed with post-valve T-cannulated growing pigs, using five animals in each experiment in a change-over design to evaluate the effect of inclusion of four different dried forage meals on ileal crude protein (CP) and amino acid (AA) digestibilities. The control diets (C1 and C2) were barley-based and the experimental diets were formulated by replacing the barley with 100 or 200 g/kg of either lucerne (Medicago sativa) or white clover (Trifolium repens) meal in Expt 1 and red clover (Trifolium pratense) or perennial ryegrass (Lolium perenne) meal in Expt 2. A decrease (P< 0·05) in the apparent ileal digestibility of CP and most of the essential and nonessential AA was found with the inclusion of lucerne, white clover and perennial ryegrass meal in the barley-based diets. When red clover meal was included, only the apparent ileal digestibilities of CP, leucine, phenylalanine, tyrosine and glutamic acid were found to decrease (P< 0·05). The estimated apparent ileal digestibilities of most essential AA in the forage meals were lower than in the barley-based diets. The ileal flow of glucosamine and ornithine was found to increase (P< 0·05) with increasing proportion of fibre in the diet, suggesting an increase in endogenous N secretions and small-intestinal microbial activity. With the minor changes found for ileal essential AA digestibilities with forage meal inclusion in the diet the present data confirm the potential of forage meals as a source of protein in pig diets.


1986 ◽  
Vol 106 (3) ◽  
pp. 445-448 ◽  
Author(s):  
T. Gerson ◽  
A. John ◽  
A. S. D. King

SummaryTwo experiments were carried out to test the effects of ryegrass maturity on rumen lipid metabolism. In the first experiment the effect of stage of maturity of perennial ryegrass on lipid metabolism in the rumen was studied with grazing sheep fitted with rumen cannulae. The pasture was either immature (13·8% crude protein), mature (8·1% crude protein) or senescent (5·5% crude protein).The ratesin vitroof triacyl glycerol lipolysis and linoleic acid (18: 2w6) hydrogenation were found to decrease with increasing age of the ryegrass.In the second experiment the sheep were dosed with emulsified linseed oil (30 g) via rumen cannulae while grazing immature or senescent ryegrass and the rumen digesta and blood plasma sampled at 0, 4 and 8 h after dosing.The proportions of linseed oil retained in the rumen were greater and blood plasma linoleic (18:2w6) and linolenic (18:3w3) acid concentrations higher when senescent ryegrass was fed.It was concluded that the rates of rumen lipolysis and hydrogenation decreased with the age of pasture and that after dosing with linseed oil the polyunsaturated fatty acid concentrations in blood plasma increased.


1973 ◽  
Vol 80 (2) ◽  
pp. 323-327 ◽  
Author(s):  
J. E. Newton ◽  
J. E. Betts

SummaryDuring 3 years, three groups of 20 Scottish half-bred ewes were grazed on perennial ryegrass, white clover or red clover. During this period the two legumes were oestrogenic, in terms of teat-length extension of wethers, but the perennial ryegrass was not. The white clover was only markedly oestrogenic when there was a high proportion of diseased leaves. The mean litter size and lambing percentage of the ewes grazed on red clover was significantly reduced. White clover, although it was oestrogenic, had no effect on mean litter size or lambing percentage. The mean litter size of the ewes on the perennial ryegrass was 2·35, 2·30 and 2·24, on the white clover was 2·20, 2·33 and 2·23 and on the red clover was 1middot;60, 1·67 and 1·78 for the three lambings. Lambing percentage of the ewes on the perennial ryegrass was 175, 225 and 218, on the white clover was 210, 222 and 189, and on the red clover was 160, 128 and 118 for the three lambings. The lambing date of the ewes grazing on the red clover was significantly later at the third lambing.


1985 ◽  
Vol 105 (1) ◽  
pp. 79-84 ◽  
Author(s):  
D. Wilman ◽  
S. K. Shrestha

SUMMARYEight canopy heights, maintained by weekly cutting, were compared during summer and early autumn on a perennial ryegrass (Lolium perenne L.)-white clover (Trifolium repens L.) sward.Perennial ryegrass adapted to a taller canopy by increasing the length of its leaf blades much more than it increased the length of its leaf sheaths, and by increasing the length of its blades proportionately more than their width. White clover adapted by increasing the length of its petioles much more than it increased the length of its leaflets. Canopy height did not affect the number of ryegrass leaves emerging or dying per tiller or the number of live, emerged leaves maintained by a tiller. The amount of herbage harvested at the weekly cuts was largely unaffected by canopy height once the swards had adapted to the particular management. Leaf blades in the taller canopies, therefore, lost a much lower proportion of their length to defoliation than those in the shorter canopies. Consequently, the length of blade dying per tiller per week was more strikingly affected by canopy height than was the rate of leaf extension. The increasing amount of material lost by death with increasing canopy height was confirmed by the weights of senescent and dead tissue collected weekly from a fixed area in each plot. Herbage in the lower compared with the upper layers of the taller canopies was much less digestible and lower in N content.


1996 ◽  
Vol 22 (3) ◽  
pp. 221-226 ◽  
Author(s):  
S. U. Sarathchandra ◽  
R. N. Watson ◽  
N. R. Cox ◽  
M. E. di Menna ◽  
J. A. Brown ◽  
...  

2021 ◽  
pp. 1-8
Author(s):  
Jesse Puka-Beals ◽  
Greta Gamig

Direct seeding into strip-tilled zones (STZs) of living mulches may require weed suppression tactics for soil surfaces exposed within the STZ. Three surface mulch options (hydromulch, compost blanket, and a no-mulch control) were evaluated for their ability to suppress weeds and improve crop performance when applied in STZs seeded to carrot (Daucus carota). These STZs were located within one of five living mulch options [red clover (Trifolium pratense), white clover (Trifolium repens), perennial ryegrass (Lolium perenne), a weed-free control, and a weedy control]. From measurements spanning 2 years at two North Dakota locations, dry weed biomass was lower in STZs where hydromulch or compost blankets were applied compared with the no-mulch control (12, 13, and 82 g·m−2, respectively). The presence of a living mulch adjacent to the STZ reduced carrot root biomass by 49% to 84% compared with the weed-free control. Further research should 1) investigate methods for reducing yield loss from living mulches, and 2) develop biodegradable alternatives to plastic mulches.


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