The digestion of pasture plants by sheep. II. The digestion of ryegrass at different stages of maturity

1968 ◽  
Vol 19 (6) ◽  
pp. 963 ◽  
Author(s):  
RH Weston ◽  
JP Hogan
Keyword(s):  
Organic Matter ◽  
Propionic Acid ◽  
Volatile Fatty Acids ◽  
Metabolizable Energy ◽  
Water Soluble ◽  
Feed Consumption ◽  
Net Energy ◽  
Dietary Nitrogen ◽  
Ad Libitum ◽  
Ad Libitum Intake

Ryegrass harvested at various stages of maturity was dried and offered to sheep either ad libitum or at approximately 90% of the ad libitum intake. Feed consumption and the times spent by the sheep in ruminating and eating were measured when the forages were offered ad libitum, and several aspects of digestion were studied when the level of feeding approached 90% of ad libitum intake. The chemical composition of the grasses and the apparent digestibility of the constituents showed the usual changes with maturity. As the grass matured, there was a tendency for: (i) the rate of flow of digesta from the abomasum to increase relative to the flow from the rumen, (ii) the concentration of organic matter in digesta leaving the abomasum to decrease, (iii) the quantity of nitrogen leaving the stomach in digesta per unit intake of dietary nitrogen to increase, and (iv) the sheep to spend more time in ruminating and eating per unit feed intake. No differences attributable to maturity were observed in: (i) the rate of flow of digesta from the rumen, (ii) the retention time of a water-soluble marker in the rumen, (iii) rumen volume, (iv) the distribution of the digestion of organic matter and carbohydrate between the stomach and intestines, and (v) the apparent digestion of nitrogen in the intestines. Although the quantity of nitrogen provided by 100 g of forage organic matter decreased with maturity from 4.3 to 1.2 g, the corresponding change in the quantity of nitrogen, in forms other than ammonia, apparently digested in the intestines was only 2.6 to 1.5 g. It was calculated, after making several assumptions, that the net energy value of the metabolizable energy derived from volatile fatty acids produced in the rumen and from amino acids digested in the intestines was little affected by the stage of maturity. On the other hand, after making assumptions about the energy costs of ruminating and eating, it was calculated that the proportion of the metabolizable energy used in ruminating and eating could increase from 5% with the immature grass to 13% with mature grass. Intraruminal infusion of propionic acid did not increase the sheep's intake of one forage that provided a relatively small quantity of propionic acid during ruminal digestion.

The digestion of chopped and ground roughages by sheep. I. Movement of digesta through the stomach

1967 ◽  
Vol 18 (5) ◽  
pp. 789 ◽  
Author(s):  
RH Weston ◽  
JP Hogan
Keyword(s):  
Retention Time ◽  
Metabolizable Energy ◽  
Water Soluble ◽  
Ad Libitum ◽  
Ad Libitum Intake ◽  
Ad Libitum Feeding

Digestion studies were conducted with lucerne hay and wheaten hay prepared for feeding either by chopping or by grinding and pelleting. The sheep were offered food every 3 hr. The rates of flow of water and the rumen volumes were measured by reference to a water-soluble marker. The replacement of a diet of chopped roughage by an equal amount of ground roughage caused a decline in the rate of flow of water from the rumen. With wheaten hay this decreased flow was accompanied by a decline in rumen volume, the retention time of the marker in the rumen remaining constant; with lucerne hay the rumen volume remained constant and the retention time of the marker increased. When the quantity of ground roughage feed was increased, rates of flow from the rumen and abomasum were enhanced and marker retention time in the rumen decreased. Under conditions of ad libitum feeding, the sheep consumed 75% more chopped lucerne hay than chopped wheaten hay; grinding was accompanied by an increase of 50% in the consumption of each hay. When levels of feeding were approximately 90% of the ad libitum intake, it was found that: (i) the rate of flow from the rumen appeared to be independent of diet and method of preparation of the feed; (ii) the rate of flow from the abomasum was higher with the ground roughage; (iii) rumen volume with ground lucerne hay was higher than with chopped lucerne hay or ground wheaten hay; it was also higher with chopped wheaten hay as compared with ground wheaten hay. Sheep spent less time ruminating and eating when the roughages were ground. The amount of metabolizable energy available for production from 1000 g of ground lucerne hay was 950 kcal; it was calculated that this would have declined by 9% if the sheep ruminated for the same time on this ground hay as on the chopped hay.

scholarly journals What is the digestibility and caloric value of different botanical parts in corn residue to cattle?1

2019 ◽  
Vol 97 (7) ◽  
pp. 3056-3070 ◽  
Author(s):  
Emily A Petzel ◽  
Evan C Titgemeyer ◽  
Alexander J Smart ◽  
Kristin E Hales ◽  
Andrew P Foote ◽  
...  
Keyword(s):  
Organic Matter ◽  
Nutrient Availability ◽  
Heat Production ◽  
Latin Square ◽  
Metabolizable Energy ◽  
Net Energy ◽  
Digestible Energy ◽  
Randomized Design ◽  
Corn Residue ◽  
Completely Randomized Design

AbstractTwo experiments were conducted to measure rates of ruminal disappearance, and energy and nutrient availability and N balance among cows fed corn husks, leaves, or stalks. Ruminal disappearance was estimated after incubation of polyester bags containing husks, leaves or stalks in 2 separate ruminally cannulated cows in a completely randomized design. Organic matter (OM) that initially disappeared was greatest for stalks and least for husks and leaves (P < 0.01), but amounts of NDF that initially disappeared was greatest for husks, intermediate for stalks, and least for leaves (P < 0.01). Amounts of DM and OM that slowly disappeared were greatest in husks, intermediate in leaves, and least in stalks (P < 0.01). However, amounts of NDF that slowly disappeared were greatest in leaves, intermediate in husks, and least in stalks (P < 0.01). Rate of DM and OM disappearance was greater for leaves, intermediate for husks and least for stalks, but rate of NDF disappearance was greatest for stalks, intermediate for leaves, and least for husks (P < 0.01). Energy and nutrient availability in husks, leaves, or stalks were measured by feeding ruminally cannulated cows husk-, leaf-, or stalk-based diets in a replicated Latin square. Digestible energy lost as methane was less (P = 0.02) when cows were fed leaves in comparison to husks or stalks, and metabolizable energy (Mcal/kg DM) was greater (P = 0.03) when cows were fed husks and leaves compared with stalks. Heat production (Mcal/d) was not different (P = 0.74) between husks, leaves, or stalks; however, amounts of heat produced as a proportion of digestible energy intake were less (P = 0.05) among cows fed leaves in comparison to stalks or husks. Subsequently, there was a tendency (P = 0.06) for net energy available for maintenance from leaves (1.42 Mcal/kg DM) to be greater than stalks (0.91 Mcal/kg DM), and husks (1.30 Mcal/kg DM) were intermediate. Nitrogen balance was greater when cows were fed leaves, intermediate for husks, and least for stalks (P = 0.01). Total tract digestion of NDF was greater (P < 0.01) for husks and leaves compared with stalks. Husks had greater (P = 0.04) OM digestibility in comparison to stalks, and leaves were intermediate. Apparently, greater production of methane from husks in comparison to leaves limited amounts of energy available for maintenance from husks even though total-tract nutrient digestion was greatest when cows were fed husks or leaves.

Factors limiting the intake of feed by sheep. I. The significance of palatability, the capacity of the alimentary tract to handle digesta, and the supply of glucogenic substrate.

1966 ◽  
Vol 17 (6) ◽  
pp. 939 ◽  
Author(s):  
RH Weston
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Polyvinyl Chloride ◽  
Dry Matter ◽  
Alimentary Tract ◽  
Control Period ◽  
Feed Consumption ◽  
Ad Libitum

Voluntary feed consumption (VFC) decreased when a quantity of the diet being consumed by the sheep was introduced into the rumen. On diets of lucerne hay, lucerne hay plus maize, wheaten hay, and wheaten straw, the decreases in VFC ranged from 90 to 110% of the quantity introduced intraruminally when this quantity varied from 20 to 60% of the VFC during control periods. When sheep consumed wheaten straw ad libitum, and a quantity of coarsely ground wheaten straw equal to 140% of the VFC during a control period was given intraruminally, VFC ceased and digesta accumulated in the rumen. VFC decreased when indigestible materials were introduced into the rumen. The voluntary consumption of lucerne hay decreased by 15% when sawdust was introduced into the rumen at a rate equivalent by weight to 17% of the VFC during a control period ; decreases of 7 and 9% were found when finely ground polyvinyl chloride was introduced at rates equivalent by weight to 25 and 50% respectively of VFC during control periods. The voluntary consumption of wheaten hay decreased by 16 and 19% when sawdust was introduced into the rumen at rates equivalent by weight to 25 and 18% respectively of VFC during control periods. Intraruminal infusions of acetic acid, propionic acid, or a mixture of acetic, propionic, and butyric acids providing 290–510 kcal of energy daily were accompanied by decreases in the voluntary consumption of lucerne hay and wheaten hay; the decreases ranged from 0.29 to 0.86 g dry matter per kcal of energy infused; similar decreases were obtained when propionic acid was infused into the abomasum of sheep given lucerne hay. The intake of lucerne hay was 9% higher when given alone than when supplemented with 6% propionic acid. The results are discussed in relation to factors limiting the intake of lucerne hay and wheaten hay.

Effect of intraruminal infusion of urea on the response in voluntary food intake by sheep

1985 ◽  
Vol 36 (3) ◽  
pp. 483 ◽  
Author(s):  
JK Egan ◽  
PT Doyle
Keyword(s):  
Organic Matter ◽  
Food Intake ◽  
Dry Matter ◽  
Block Design ◽  
Ammonia Nitrogen ◽  
Dry Matter Intake ◽  
Plant Cell Walls ◽  
Randomized Block Design ◽  
Ad Libitum ◽  
Ad Libitum Intake

Six mature Merino sheep received three treatments in a randomized block design experiment. The treatments were: chopped oaten hay diet at 90% of ad libitum intake without urea (L); the ciet offered at the same level as for L with urea infused into the rumen at 11.5 g kg-1 dry matter intake (LU); and the diet offered at 90% of the ad libitum intake achieved with urea infused at 11.5 g kg-1 dry matter intake (HU). Sheep given HU consumed 37% more (P < 0.01) organic matter (OM) than those fed L or LU, but the apparent digestibility of OM did not vary (59.2-61.8%) between treatments. The addit onal food consumption was associated with c. 20% increase (P < 0.05) in the weight of OM in the reticulorumen and significantly higher (by 10-35%; P < 0.05) fractional outflow rates of most dietary and microbial constituents of digesta. The fractional digestion rate of potentially digestible plant cell walls was not affected by urea, but the flow of microbial non-ammonia nitrogen from the abomasum was enhanced (L, 7.0; LU, 8.2; HU, 12.5 g day-1; P < 0.05). The results of this study suggest that the stimulatory effect of urea upon food intake was associated with the provision of additional microbial protein for digestion in the intestines, rather than changes in the rate or extent of organic matter fermentation in the reticulorumen.

Studies on the production of volatile fatty acids from grass by rumen liquor in an artificial rumen: II. The volatile fatty acid production from dried grass

1957 ◽  
Vol 49 (2) ◽  
pp. 171-179 ◽  
Author(s):  
A. John ◽  
G. Barnett ◽  
R. L. Reid
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Propionic Acid ◽  
Metabolic Pathways ◽  
Volatile Fatty Acid ◽  
Volatile Fatty Acids ◽  
Water Soluble ◽  
Fatty Acid Production ◽  
Growing Seasons ◽  
Titration Curves

1. A study has been made of the production of volatile fatty acids obtainable from dried grass and its gross water-soluble and water-insoluble separates, in the artificial rumen, over two growing seasons.2. In contradistinction to fresh grass, the dried grass gives a consistent production of acetic acid proportionately greater than propionic acid, at all stages of maturity, but when aqueous extracts of the dried grass, and the resultant extracted grass, respectively, are examined separately in the artificial rumen, it is found that the former yield preponderating amounts of acetic acid while the latter give amounts of propionic acid equal to, or exceeding, the corresponding productions of acetic acid.3. An examination of the titration curves for the total acids obtained from the dried grass, extracted grass and grass extract runs, indicates an approach to an incomplete relationship between the residual carbohydrate in the extracted grass and cellulose, while the grass extract reveals itself as the chief source of acetic acid in the whole dried grass, the acid being formed very speedily at the start of the run.4. The suggested sources and some of the possible metabolic pathways involved in the formation of v.f.a. from grass are discussed in the text.

Determination of the yield characteristics and in vitro digestibility of barley forage harvested in different vegetation periods

2016 ◽  
Author(s):  
Mehtap Guney ◽  
Cagri Kale ◽  
Duran Bolat ◽  
Suphi Deniz
Keyword(s):  
Organic Matter ◽  
Dry Matter ◽  
Energy Content ◽  
Vegetation Period ◽  
Metabolizable Energy ◽  
Mature Stage ◽  
In Vitro Digestibility ◽  
Net Energy ◽  
Seed Formation

This study planned to determine the differences among nutrient composition, in vitro digestibility, energy content, digestible dry matter and organic matter yields of barley forage harvested at three different stages of maturity. Each vegetation period (heading stage, seed formation stage and mature stage) was randomly assigned to 5 replication from 1 square meter area and fifteen samples were harvested in total. DM, ADF (p<0.001), and NDF (p<0.05) contents were different in each stages of barley forage. In vitro dry matter (IVDMD), organic matter digestibility (IVOMD), metabolizable energy (ME), and net energy for lactation (NEL) values of samples were determined to be lower than the other two stages at the mature stage (p<0.05). Yield parameters of barley were significantly affected by vegetation period (p<0.001). It can be concluded that all three vegetation period had significantly higher digestibility. Digestible DM, OM and energy yields were higher when harvested at the mature stage of vegetation.

Net energy value of timothy and bromegrass silages for beef cattle

1998 ◽  
Vol 78 (1) ◽  
pp. 107-114 ◽  
Author(s):  
D. R. Ouellet ◽  
J. R. Seoane ◽  
H. Lapierre ◽  
P. Flipot ◽  
J. F. Bernier
Keyword(s):  
Beef Cattle ◽  
Heat Production ◽  
Stem Elongation ◽  
Prediction Equation ◽  
Metabolizable Energy ◽  
Net Energy ◽  
Beef Steers ◽  
Boot Stage ◽  
Ad Libitum ◽  
Net Energy Value

Metabolizable energy (ME), net energy for maintenance and net energy for growth of grass silages were evaluated by the comparative slaughter technique using a 2 × 2 × 3 factorial design. Sixty medium frame beef steers (259 ± 29 kg BW) were divided in groups of five and fed during 3 months either Timothy (T) or Bromegrass (B) harvested at stem elongation (S) of the first cut or at boot stage of the aftermath (A). Forages were fed at one of three levels of intake: ad libitum (FF), 80% of FF, or 65% of FF. Silages averaged 26.9% DM, 16.0% CP and 37.7% ADF. Regression of logarithm of heat production (HE) against ME intake were similar for all silages (log HE = 0.00046*ME + 2.4923; r2 = 0.89). From this equation, fasting HE of 311 kJ kg−0.75 d−1, ME for maintenance of 559 kJ kg−0.75 d−1 and efficiency of utilization of energy for maintenance of 56% were determined. Regression of ME intake against retained energy (RE) were similar for all silages. Efficiency of ME utilization for growth was 33% using the regression of ME over RE with a ME requirement for maintenance fixed at 559 kJ kg−0.75 d−1. Net energy for maintenance and growth were similar for all silages, averaging 6.17 and 3.70 MJ kg−1, respectively. The use of a prediction equation based on ADF of forages underestimated ME values of silages by approximately 25%. Moreover, NRC (1984) equations that estimate NE from experimentally estimated ME values tended to overestimate the net energy of our grass silages. Key words: Net energy, grass silages, timothy, bromegrass, beef cattle

Factors limiting the intake of feed by sheep. VIII.* The roughage requirement of the ruminant lamb fed on concentrate diets based on wheat

1974 ◽  
Vol 25 (2) ◽  
pp. 349 ◽  
Author(s):  
RH Weston
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Volatile Fatty Acids ◽  
Body Weight Gain ◽  
Whole Grains ◽  
Water Soluble ◽  
Feed Consumption ◽  
Whole Grain ◽  
Wheat Grain ◽  
Whole Wheat

The voluntary feed consumption (VFC) and body weight gain of lambs initially 12 weeks old and weighing 22 kg were measured when diets based on whole wheat grain and varying in straw content were offered. The basal diet comprised, on an organic matter (OM) basis, about 82 parts whole wheat grain and 18 parts protein concentrate; ground wheaten straw was added to provide diets with 2%, 7% or 13% straw. Daily VFC, expressed in relation to body weight in kg0.75 (BW0.75), increased from 85.6 with 2% straw through 90.4 with 7% straw to 94.2 with 13% straw. The corresponding OM digesti bilities were calculated to range from 84.8 to 77.6%. However, the intake of digestible OM and the rate of body weight gain were not affected by the straw content of the diet, the respective mean values for all lambs being 73g/day BW0.75 and 293 g/day. Lambs initially 25 weeks old and weighing 38 kg were offered a diet (2% straw) based on wheat in which the wheat was presented either as whole grains or in ground and pelleted form. With the whole grain diet the daily rates of OM intake, digestible OM intake and body weight gain were 75.6 g/ BW0.75, 64.7 and 254 g respectively; the corresponding values with the ground grain diet were about 20% lower. Studies involving the slaughter of animals showed that a large proportion of the wheat grain consumed reached the rumen in the form of whole grains and these contributed significantly to the dry matter of the ruminal digesta. The rate of ruminal digestion of whole wheat grains was slow (37% in 96 hr) when the sheep were given a diet based on wheat. By contrast, when a roughage diet was consumed the rate was high (81% in 96 hr). Fractured grain was rapidly digested in the rumen (67% in 20 hr). The mean residence time of water-soluble marker in the rumen and the rate of digesta flow from the rumen were greater in fistulated sheep given a whole grain diet than with a ground grain diet. The diets also differed with respect to the concentration of potassium in rumen liquor, the rumen potassium pool size and the rate of flow of sodium and volatile fatty acids to the omasum. It was concluded that the roughage requirement of the ruminant lamb fed on concentrate diets based on whole wheat did not exceed the equivalent of 2 g ground straw per 100 g diet. The possibility of a higher roughage requirement with ground wheat diets is suggested. ___________________ *Part VII, Aust. J. Agric. Res., 24: 387 (1973).

scholarly journals Alfalfa Protein Concentrate as a Less Ruminally Degradable Protein Source for High-Producing Dairy Cows

1997 ◽  
Vol 2 ◽  
pp. 31
Author(s):  
C.D. Lu ◽  
NA. Jorgensen
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Crude Protein ◽  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Ammonia Nitrogen ◽  
Neutral Detergent Fiber ◽  
Net Energy ◽  
Protein Concentrate ◽  
Dietary Nitrogen

Ten multiparous Holstein cows were used in a 105-day continuous feeding trial to compare soybean meal (SBM) and alfalfa protein concentrate (APC) as supplemental protein sources for high-producing dairy cows. Dairy cows with an average milk production of 35.2 kg/day were paired and randomly assigned to one of the treatments. A double reversal design was employed With 35 days per period. The comparison between treatments was made during the last 21 days of each period. Experimental diets, containing 60% corn silage and 10% alfalfa hay, were formulated to be isonitrogenous and isoenergetic (crude protein. 15.6%; net energy tor lactation, 1.60 Mcal/kg DM). Fifty percent of dietary nitrogen was provided by test proteins. Animals were fed four times daily. Chromie oxide boluses, 50 g/day were used to estimate digestion coefficients. Ruminal protein degradability in viva (%) and in situ(%)were 56.8, 68.3 and 47.3. 35.3 for SBM and APC, respectively. Dry matter intake (kg/day) was 19.1 and 18.6 for cows fed SBM and APC. respectively. Rummal parameters cows fed SBM vs APC were, pH. 6.6 vs 6.7, ammonia nitrogen(mg/dI) 10.8 vs 6.2(p less than 0.01); total volatile fatty acids (mM), 86.3 VS 84.6(P LESS THAN 0.05), acetate (%) , 50.8 vs 64.9 (p less than 0.01); propionate dry matter , 65.3 vs 61.8; crude protein . 67.6 vs 61.1 (P less than 0.05 ) neutral detergent fiber , 51.1 vs 52.5 ; acid detergent fiber, 47.7 vs 49.0 . A slightly higher (P more than 0.05 ) amount of milk was produced by cows fed APC(28.6+_ 3.5 vs 28.2+- 3.8 kg/day). Each additional gramof undergradable intake protein provided by APC continued to a 5- gram increase in 4% fat-corrected milk production.

scholarly journals Influence of sulfur on the fermentation characteristics of corn distiller’s dried grains with solubles in in vitro culture

2017 ◽  
Vol 62 (No. 10) ◽  
pp. 417-425
Author(s):  
L. He ◽  
H. Wu ◽  
W. Chen ◽  
Q. Meng ◽  
Z. Zhou
Keyword(s):  
In Vitro Culture ◽  
Production Rate ◽  
Volatile Fatty Acids ◽  
Ammonia Nitrogen ◽  
Gas Production ◽  
Metabolizable Energy ◽  
Composition Analysis ◽  
Sulfur Source ◽  
Net Energy

The effects of sulfur on the fermentation characteristics of corn distiller’s dried grains with solubles (DDGS) in in vitro culture were investigated. Samples (DDGS) were analyzed for nutrient values and then two independent in vitro experiments were conducted to study the effects of various sulfur sources (Na<sub>2</sub>S, Na<sub>2</sub>S<sub>2</sub>O<sub>4</sub>, Na<sub>2</sub>SO<sub>3</sub>, and Na<sub>2</sub>SO<sub>4</sub>) and different sulfur levels (0.346, 0.692, and 1.038%) on the fermentation characteristics of DDGS. Based on sampling and chemical composition analysis, there existed a great variation in the concentrations of sulfur and proximate nutrients of DDGS. In Experiment 1, sulfur source showed a significant (P &lt; 0.01) effect on the gas production parameters (asymptotic gas production (b) and gas production rate (c)) and gas production of DDGS – sulfur from Na<sub>2</sub>SO<sub>4</sub> and Na<sub>2</sub>S produced more (P &lt; 0.01) gas within 48 h with a faster gas production rate as well as higher digestibilities (dry matter degradability and organic matter digestibility) and more energy supplies (metabolizable energy), net energy for maintenance and gain, and net energy for gain than sulfur from Na<sub>2</sub>SO<sub>3</sub> and Na<sub>2</sub>S<sub>2</sub>O<sub>4</sub>. Neither ammonia-nitrogen (NH<sub>3</sub>-N) concentration nor volatile fatty acids (VFA) profile (total VFA and individual VFA proportion) were affected by sulfur source (P &gt; 0.05). In Experiment 2, no significant (P &gt; 0.05) effect on the fermentation characteristics of DDGS with increasing sulfur content was found. The collective findings suggest that regular chemical analyses are necessary to make full use of DDGS, and that the valence state of sulfur in DDGS exerts an effect on its in vitro fermentation characteristics and there appears no dose-related effect of sulfur on the fermentation of DDGS in a short-term in vitro culture.

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