Spray-topping annual grass pasture with glyphosate to delay loss of feeding value during summer. II . Herbage intake, digestibility, and diet selection in penned sheep

1999 ◽  
Vol 50 (4) ◽  
pp. 465 ◽  
Author(s):  
B. J. Leury ◽  
C. Siever-Kelly ◽  
R. J. Simpson ◽  
K. L. Gatford ◽  
H. Dove
Keyword(s):  
Volatile Fatty Acids ◽  
Nutritive Value ◽  
Soluble Carbohydrates ◽  
Soluble Carbohydrate ◽  
Individual Plant ◽  
Plasma Urea ◽  
Preference Testing ◽  
Plant Parts ◽  
Seed Head ◽  
Herbage Intake

The treatment of annual ryegrass–silver grass pasture with the herbicide glyphosate at seed head emergence delayed the loss of soluble carbohydrates and improved herbage digestibility. The present study investigated whether this improvement in nutritive value had any influence on the diet preference, intake, and performance of housed sheep. Since the effects of glyphosate on digestibility were most marked in stem tissue, preference was examined not only in relation to sprayed v. unsprayed herbage, but also in terms of preference for individual plant parts. In the preference testing, sheep showed a marked preference for sprayed rather than unsprayed herbage. They also consumed more of it, such that their digestible dry matter intake from sprayed herbage was nearly twice that from unsprayed herbage. When sheep were offered different plant fractions from the control herbage, they selected against stem material and preferred leaf or seed head. By contrast, when offered fractions from the sprayed material, they preferred stem to leaf, but showed no strong preference for stem over seed head. Preference was related more to the soluble carbohydrate content of a plant part than its digestibility, and only when soluble carbohydrate contents were similar was there preference for the more digestible material. The consumption of sprayed herbage, compared with control herbage, led to higher concentrations of rumen volatile fatty acids in the period 4 h after feeding. Moreover, the feeding of these herbages over a 6-week period resulted in significant reductions in pre-feeding plasma urea and β-hydroxybutyrate concentrations. When control herbage was fed with supplements of fructose, urea, or fructose+urea, in an attempt to mimic the possible differences in nutritive value between control and sprayed herbage, the responses in rumen and blood metabolites were less marked than when sprayed herbage was fed. As a consequence of the higher nutritive value of the sprayed herbage and the higher intakes by the animals fed this material, sheep fed sprayed herbage were able to maintain weight over the feeding period, whereas those offered the control herbage lost weight at 130–150 g/day

Spray-topping annual grass pasture with glyphosate to delay loss of feeding value during summer. III. Quantitative basis of the alkane- based procedures for estimating diet selection and herbage intake by grazing sheep

1999 ◽  
Vol 50 (4) ◽  
pp. 475 ◽  
Author(s):  
H. Dove ◽  
J. T. Wood ◽  
R. J. Simpson ◽  
B. J. Leury ◽  
T. A. Ciavarella ◽  
...  
Keyword(s):  
Diet Composition ◽  
Nutritive Value ◽  
Diet Selection ◽  
Leaf Sheath ◽  
Multivariate Statistical ◽  
Plant Parts ◽  
Seed Head ◽  
Herbage Intake ◽  
Quantitative Basis ◽  
Objective Basis

Previous papers in this series have demonstrated that, when annual pastures were sprayed at seed head emergence with low rates of the herbicide glyphosate, the nutritive value of the sprayed herbage was improved. Housed sheep preferred sprayed herbage to unsprayed herbage and, within sprayed herbage, appeared to have a preference for stem material. The housed sheep ate more of the sprayed material and their weight gains were improved. If such responses occurred in grazing animals, they could result in substantial improvements in animal liveweights or wool production. The present paper describes the alkane-based procedures used to investigate diet selection and herbage intake in grazing animals, with the emphasis placed on methodological and statistical issues. The alkane concentrations in the plant fractions (leaf, leaf sheath, stem, seed head) of sprayed and unsprayed herbage are reported. Similarly, the alkane concentrations in extrusa samples collected by oesophageally fistulated sheep given access to the grazed areas, and in the faeces of sheep grazing the areas, are reported. Patterns of alkane concentrations in extrusa and faeces were similar and indicated that, in the short term, oesophageally fistulated animals consumed a diet of similar composition to that selected by the animals resident on the plots. Using these data for alkane concentrations, multivariate statistical analyses are presented which provide an objective basis for selecting the alkanes to be used in the estimation of diet selection. The results of the first of 4 grazing periods are presented, as an example of the application of the alkane-based procedures for estimating herbage intake and, in particular, diet composition. Use of these techniques indicated that, when given access to sprayed senescent pasture, sheep consumed more digestible dry matter and selected more of it from the stem fraction than was the case with unsprayed herbage. These results are similar to those found with housed animals and demonstrate that patterns of herbage and faecal alkane concentrations can be used to estimate diet composition of grazing animals in terms of the plant parts on offer

Spray-topping annual grass pasture with glyphosate to delay loss of feeding value during summer. IV. Diet composition, herbage intake, and performance in grazing sheep

1999 ◽  
Vol 50 (4) ◽  
pp. 487 ◽  
Author(s):  
B. J. Leury ◽  
C. Siever-Kelly ◽  
R. J. Simpson ◽  
K. L. Gatford ◽  
H. Dove
Keyword(s):  
Diet Composition ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Sheep Grazing ◽  
Annual Grass ◽  
Plant Parts ◽  
Seed Head ◽  
Herbage Intake ◽  
Grazing Sheep ◽  
Days After Anthesis

We report the effects of spray-topping annual grass pasture with glyphosate (180 g a.i./ha as Roundup CT, at the seed head emergence stage) on the nutritive value of herbage and on subsequent performance of grazing sheep. Eight 1-ha plots, consisting of 4 sprayed and 4 unsprayed (control) plots, were set-stocked with Merino wethers (18 months old, 12 sheep/ha) from 8 days after anthesis in the control plots (late spring) until 165 days after anthesis (mid-autumn). In 4 periods (15–20, 36–41, 71–76, and 99–104 days after anthesis; Periods 1–4, respectively) sheep were dosed with synthetic alkanes and herbage and faecal samples were taken, in order to estimate diet composition (in terms of plant parts), faecal output, herbage intake, and the digestibility of the whole diet. As described in our earlier papers, spray-topping reduced the yield of pasture dry matter, but also slowed the loss of water-soluble carbohydrate (WSC) and digestibility during pasture senescence. The present paper shows that as a result, sheep grazing sprayed herbage in Periods 1 and 2 consumed significantly more organic matter (OM) and digestible OM (DOM) than sheep grazing the control pasture. Their diet contained a higher proportion of stem with a higher WSC concentration than that of the sheep grazing the control plots. The proportions of different plant parts (leaf blade+sheath, stem, seed head) in the diet of both the plot sheep and oesophageally fistulated (OF) sheep, which grazed treatments for short periods, differed significantly between treatments in all periods. However, the compositions of the diets selected by plot and OF sheep were similar. These results confirmed diet preferences measured using housed sheep and demonstrate the usefulness of alkane-based procedures for quantifying diet composition and intake in grazing animals. As a result of their higher intake of DOM, sheep grazing sprayed herbage had a significantly higher liveweight gain over the first 2 periods (40 g/day). In Period 3, sheep grazing sprayed herbage consumed more OM than sheep grazing control herbage. However, DOM intakes from sprayed or control plots were not significantly different in either Period 3 or Period 4, and were lower than in Periods 1 and 2. Sheep grazing both treatments lost liveweight at a similar rate over this time. Wool growth in sheep grazing sprayed herbage was improved by 10% during the experimental period; wool strength was also improved significantly. The implications for the management of sheep grazing spray-topped pastures over summer are discussed.

Spray-topping annual grass pasture with glyphosate to delay loss of feeding value during summer. I. Effects on pasture yield and nutritive value

1999 ◽  
Vol 50 (4) ◽  
pp. 453 ◽  
Author(s):  
B. J. Leury ◽  
C. Siever-Kelly ◽  
R. J. Simpson ◽  
K. L. Gatford ◽  
T. A. Ciavarella ◽  
...  
Keyword(s):  
Nutritive Value ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Annual Grass ◽  
Plant Parts ◽  
Seed Head ◽  
Grass Sward ◽  
Pasture Yield ◽  
Days After Anthesis

Annual grass pasture (mainly annual ryegrass) was treated at seed head emergence (12 October 1990) with the herbicide glyphosate to delay loss of digestibility during late spring and summer. The lowest rate of glyphosate application needed to retain a high digestibility in the dry matter (DM) of the senescent grass sward was 180 g a.i./ha. The in vitro DM digestibility of control (unsprayed) pasture declined rapidly from relatively high levels near anthesis (28 October) (77–86%, leaves and seed head; 66%, stems) until about 38 days after anthesis (51–71%, leaves and seed head; 24%, stem). Thereafter, the digestibility of the plant parts did not change appreciably over at least 4 months. Treatment with glyphosate significantly slowed the loss in digestibility of stem, leaf sheaths, and seed head but did not affect the decline in digestibility of leaf blades. For example, the digestibility of stem in the sprayed pasture was 26 percentage units higher than that in the control pasture 38 days after anthesis. If the time at which digestibility of stems reached 50% is taken as an indication, the effective delay in loss of digestibility was of the order of 5 weeks. However, improved digestibility in the treated pasture was achieved at the expense of pasture yield, with the peak yield of control pasture being 4 t DM/ha (45%) higher than that of the treated pasture. Improved digestibility in treated grass pasture was mainly associated with delayed loss of water-soluble carbohydrates (WSC), except in the seed head. Improved cell wall (neutral detergent fibre) digestibility also contributed to varying degrees and was the main factor contributing to improved digestibility in the seed head. The major WSC present in the treated pasture was fructan. The crude protein concentrations of all plant parts of the senescent pasture, except the leaf blades, were also increased by treatment with glyphosate.

NUTRITIVE VALUE OF FORMALDEHYDE-TREATED RAPESEED MEAL FOR DAIRY CALVES

1972 ◽  
Vol 52 (2) ◽  
pp. 363-371 ◽  
Author(s):  
H. R. SHARMA ◽  
J. R. INGALLS ◽  
J. A. McKIRDY
Keyword(s):  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Nutritive Value ◽  
Rumen Fluid ◽  
Protein Digestibility ◽  
Rapeseed Meal ◽  
Dairy Calves ◽  
Plasma Urea ◽  
Significant Difference ◽  
Daily Gain

Treatment of oilseed meals with formaldehyde (FA) and glutaraldehyde (GA) significantly (P < 0.01) reduced the solubility of protein in 0.02 N NaOH and the production of NH3 in the artificial rumen. Ten Holstein and Holstein × Brown Swiss calves of both sexes were fed two test rations containing either 26% untreated or formaldehyde-treated (5.6 g FA per 100 g protein) rapeseed meal (FA-treated RSM) for 14 weeks. Plasma urea nitrogen (N) and rumen NH3 levels were significantly (P < 0.01) lower in the FA-treated RSM calves compared with the control calves during the first 8 weeks of the growth trial. No significant difference (P > 0.05) in dry matter consumption, daily gain, or feed efficiency was observed. Total volatile fatty acids (VFA) (mmoles/100 ml) concentration was significantly higher (P < 0.05) in rumen fluid from the control calves compared with those receiving treated RSM. Molar percentages of the VFA’s were not significantly different (P > 0.05) between the two groups. In the N balance and digestibility trial, dry matter consumption did not differ significantly (P > 0.05); however, the FA-treated RSM resulted in decreased (P < 0.05) dry matter and crude protein digestibility. Calves receiving the treated RSM had reduced (P < 0.01) urinary N excretion; however, there was no significant effect (P > 0.05) on N consumption and retention.

The use of sheep fitted with oesophageal fistulas to measure diet quality

1964 ◽  
Vol 4 (12) ◽  
pp. 71 ◽  
Author(s):  
GW Arnold ◽  
WR McManus ◽  
IG Bush ◽  
J Ball
Keyword(s):  
Daily Intake ◽  
Sampling Period ◽  
Complete Recovery ◽  
Mean Value ◽  
Soluble Carbohydrates ◽  
Soluble Carbohydrate ◽  
Botanical Composition ◽  
Herbage Intake ◽  
Sources Of Variation ◽  
Sampling Procedures

Ewes and wethers with oesophageal fistulas were compared with normal sheep in several experiments over three years. The grazing behaviour, herbage intake, liveweight changes, and ability to bear and rear lambs were altered little by fistulation, provided fistulas were less than 5 cm in length and closure of the fistulas was good. This was so even at a relatively high stocking rate of G ewes to the acre. These findings infer that studies with fistulated sheep provide information validly applicable to normal sheep. Fistulas that allowed good closure control (<5 cm in length) did not always allow complete recovery of ingested material. However, with incomplete recovery representative diet samples were obtained. Sampling procedures for obtaining adequately representative diet samples for individual sheep, and for obtaining estimates of diet composition for flocks of sheep on different pastures were established. The routine that must be followed to avoid obtaining untrue diet samples is to sample sheep when they are accustomed to a pasture, without prior fasting, and at the time(s) of the day when sheep are normally grazing. An hour's sampling period will collect about l/l0th of the total daily intake and longer periods may cause rumen dysfunction. Pooling data from once-a-day samples for two successive days for an individual sheep seemed to give accurate values for the whole diet over those two days for sheep set stocked on pasture. Variation between-sheep, between-days, and within-days in the nitrogen and soluble carbohydrate content and botanical composition of extrusa samples was studied. The contribution of these sources of variation to total variation differed for different diet constituents. For nitrogen, between-sheep variation was greater than between-day variation but for soluble carbohydrates the position was reversed. Within-day variation was much the same as between-day variation in a constituent. The standard deviations of nitrogen and soluble carbohydrate contents and botanical composition were large and a true mean value for any of these parameters for a flock of sheep, could only be obtained by pooling data for several sheep on several successive days.

scholarly journals Fermentation and nutritive value of silage and hay made from the aerial part of cassava (Manihot esculenta Crantz)

2004 ◽  
Vol 61 (4) ◽  
pp. 364-370 ◽  
Author(s):  
Eduardo Zambello de Pinho ◽  
Ciniro Costa ◽  
Mario De Beni Arrigoni ◽  
Antonio Carlos Silveira ◽  
Carlos Roberto Padovani ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Manihot Esculenta ◽  
Aerial Part ◽  
Volatile Fatty Acids ◽  
Nutritive Value ◽  
Animal Feed ◽  
Soluble Carbohydrates ◽  
Manihot Esculenta Crantz ◽  
Cassava Plant ◽  
Dry Matter Concentration

Cassava (Manihot esculenta Crantz), although native to Brazil, is still underutilized, especially when it comes to using its aerial part. In order to study the potential of the cassava plant for use as animal feed, the present work evaluated the characteristics of the aerial part of cassava when submitted to the processes of ensiling and haymaking. Treatments consisted of: aerial part of the plant ensiled without wilting (PAS); aerial part ensiled after wilting (PAE), and aerial part made into hay (PAF). Chemical analyses were run in order to evaluate the traits that determine the nutritional value of silage and hay. Wilting increased dry matter concentration from 25% to 27.7%, without changing the concentration of soluble carbohydrates (33.3 and 35.5% in the PAS and PAE, respectively), as well as buffer capacity (204 mmol kg-1 DM in PAS and 195 mmol kg-1 DM in PAE). Neither pH (3.57 in fresh silage and 3.60 in PAE) nor the ADIN concentration (11.32% of total nitrogen in PAS and 9.99% of total nitrogen in PAE) differed between the silages, but ADIN concentration was higher in hay (15.39%). Wilting caused an increase in the concentration of ammonia (from 6.5% of total nitrogen in PAS to 13.0 of total nitrogen in PAE). The levels of volatile fatty acids did not change with wilting. The ensiling process reduced the concentrations of free hydrocyanide (HCN), without, however, affecting cyanohydrin.

THE INTAKE AND DIGESTIBILITY OF AMMONIATED CEREAL STRAWS BY CATTLE

1978 ◽  
Vol 58 (3) ◽  
pp. 471-478 ◽  
Author(s):  
G. M. J. HORTON
Keyword(s):  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Nutritive Value ◽  
Latin Square ◽  
Crude Fiber ◽  
Plasma Urea ◽  
Ambient Temperatures ◽  
Ruminal Ph ◽  
Dry Matter Digestibility ◽  
Oat Straw

The effects of treatment with 3.5% anhydrous ammonia on the nutritive value of straws from Neepawa wheat, Bonanza barley and Random oats were investigated with growing Hereford steers. Ambient temperatures during the 6-wk post-treatment period were 0.1 °C for wheat and barley straws and 15 °C for oat straw. The four treatments were untreated and ammoniated straw, fed with or without 4-kg supplements per day over four periods to four steers in a 4 × 4 latin square design. Crude protein was doubled in wheat and barley straws and trebled in oat straw following ammoniation. The consumption of all three straws without concentrates was increased significantly by ammoniation. Apparent digestibility of dry matter and crude fiber on straw rations were higher (P < 0.05) in ammoniated wheat and oat straw than in the corresponding untreated straws. Neither straw intake nor dry matter digestibility were improved (P > 0.05) by ammoniation when supplements were fed, though crude fiber digestibility was increased (P < 0.05) in wheat and oat straw rations. Straw treatment had no effect (P > 0.05) on ruminal pH, dehydrogenase activity, or total or molar proportions of volatile fatty acids. Ruminal ammonia concentrations were higher (P < 0.01) for ammoniated than for untreated straws fed alone and similar to those when concentrates were also fed. Plasma urea, measured 0, 0.5, 1, 2, 4 and 7 h post-prandial, was highest in steers fed ammoniated wheat and oat straw and lowest when untreated straw was fed alone.

Effect of condensed tannins inLotus pedunculatuson the nutritive value of ryegrass (Lolium perenne) fed to sheep

1995 ◽  
Vol 125 (2) ◽  
pp. 291-297 ◽  
Author(s):  
G. C. Waghorn ◽  
I. D. Shelton
Keyword(s):  
Lolium Perenne ◽  
Condensed Tannins ◽  
Volatile Fatty Acids ◽  
Nutritive Value ◽  
Major Effect ◽  
Substantial Effect ◽  
Feeding Trial ◽  
Plasma Urea ◽  
Principal Finding ◽  
Lotus Pedunculatus

SUMMARYA feeding trial was undertaken in Palmerston North, New Zealand in 1991, to determine the extent to which condensed tannins (CT) inLotus pedunculatuswere able to affect the nutritive value of ryegrass (which does not contain CT) for sheep. The trial involved three groups of 11 male cryptorchid sheep held in metabolism crates so that intakes, digestibilities and nitrogen balances could be measured over a 42-day feeding period. One group was fed freshly cut ryegrass (Lolium perenneL.) as a sole diet (Grass group) and the other two groups were given a mixture of about one third freshly cut lotus and two thirds ryegrass (dry matter (DM) basis). This mixture containedc. 1·8% CT in the DM. One group given the mixed diet was drenched twice daily with polyethylene glycol (PEG; PEG group) to bind and remove the effects of the CT from the diet, whilst those not drenched were designated the ‘Tannin’ group. Intakes of all groups were constrained to that of the Grass group of sheep.Condensed tannins in the lotus had a major effect on the digestion of ryegrass. When the forages were immature, apparent digestibility of nitrogen (N) was substantially reduced in the Tannin sheep (65·3%)compared to the PEG (77·5%) and Grass (77·9%) groups (P< 0·001). With mature forages, the respective values were 48·8, 62·5 and 53·7% (P< 0·01). Rumen ammonia concentrations and plasma urea concentrations were also reduced by CT. Condensed tannins reduced DM digestibility by 3·7 percentage units (P< 0·05) mainly through the effects on N digestion. Concentrations of acetate, propionate and butyrate in rumen liquor were not affected by treatment, but CT reduced the proportions of the minor volatile fatty acids (VFA; isobutyrate, valerate and isovalerate). Treatment did not affect liveweight gain (131—164 g/day), or wool growth from mid-side patches, and N retention was not reduced by CT, so that the nutritive value of the forage was maintained despite the reduction in N digestibility. The principal finding was that CT inLotus pedunculatuswere able to affect the digestibility of both grass and lotus when fed together, and that as little as 1·8% of CT in the dietary DM had a substantial effect on rumen function.

The use of plant wax alkanes as marker substances in studies of the nutrition of herbivores: a review

1991 ◽  
Vol 42 (6) ◽  
pp. 913 ◽  
Author(s):  
H Dove ◽  
RW Mayes
Keyword(s):  
Plant Species ◽  
Chemical Constituents ◽  
Individual Plant ◽  
Botanical Composition ◽  
Plant Parts ◽  
Herbage Intake ◽  
Marker Substances ◽  
Pulse Dose ◽  
Sampling Procedures ◽  
Plant Wax

This review discusses the potential use of plant wax components, especially n-alkanes, as markers for estimating herbage intake, estimating the botanical composition of consumed herbage and studying digesta kinetics. Previous approaches to making these measurements are discussed briefly. Attention is drawn to the fact that current methods for estimating intake do not adequately allow for differences between individual animals. It is also suggested that the markers currently used to estimate botanical composition or study digesta kinetics are inadequate. The nature of the chemical constituents of plant waxes is briefly discussed and the concept of using alkanes to estimate intake is introduced. Particular emphasis is given to the fact that although the recovery of alkanes in faeces is not complete, intake can still be estimated using a pair of alkanes (one natural, one dosed) provided these have similar faecal recoveries. The accuracy of estimation of intake is discussed in terms of: obtaining a representative sample of herbage; alkane dosing and faecal sampling procedures; validity of the assumption of similar recoveries for the natural and dosed alkanes; sample preparation and analysis. Published comparisons of estimated and actual intakes are presented, with the conclusion that satisfactory results are obtained if intake is estimated using natural C33 alkane and dosed C32 alkane. The use of the different patterns of alkanes in herbage species, as a means of estimating botanical composition, is then discussed. Results are presented showing this can be done successfully with herbage mixtures or oesophageal extrusa. Procedures are then described for making the corrections for incomplete faecal alkane recovery, necessary to estimate the botanical composition of the herbage consumed by the free-grazing animal. This allows the quantification of the intake of individual plant species by individual animals, and it is suggested that this can be achieved without the need for oesophageally-fistulated (OF) animals. Differences in alkane levels between plant parts within a species are then discussed. It is suggested that these can lead to error in the estimation of intake, if OF animals should consume plant parts different from those consumed by the test animals. However, it is also suggested that differences in alkane levels between plant parts can be used to quantify the intake of these parts, in a manner analogous to the estimation of the intake of individual plant species. The usefulness of alkanes in studies of digesta kinetics is then discussed, principally in relation to the natural alkanes, which remain intimately associated with plant particles in the gut. It is suggested that natural alkanes could prove excellent markers for studies of particle breakdown and digesta flow. The preparation of natural 14C-labelled alkane, for use as a pulse dose in mean retention time studies, is also discussed.

scholarly journals GENOTYPIC AND ENVIRONMENTAL EFFECTS ON CARBOHYDRATE DISTRIBUTION IN POTATO

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 856f-856
Author(s):  
Peng Hwang ◽  
J. Creighton Miller ◽  
B. Greg Cobb
Keyword(s):  
Starch Content ◽  
Field Studies ◽  
Soluble Carbohydrates ◽  
Soluble Carbohydrate ◽  
Plant Parts ◽  
Study Results ◽  
Production Area ◽  
College Station ◽  
Growing Conditions ◽  
Major Production Area

Field studies were conducted at two Texas locations: Lubbock, near the major production area for Texas potatoes, and College Station which is hotter and more humid. Early and late plantings were established at each location to compare cool and hot growing conditions. Nine genetically diverse cultivars, including those previously reported to be heat resistant or susceptible, were used in this study. Results indicated that the distribution of soluble carbohydrate and starch differed significantly among plant parts. In leaves and stems, glucose and fructose were the major soluble carbohydrates, while sucrose was the major soluble carbohydrate in tubers. Total soluble carbohydrate and starch content in leaves, stems and roots from the early plantings were significantly higher than those from the late plantings. Inositol increased significantly in the College Station late stress environment.

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