Higher Dry Matter Digestibility Research Articles

Selecting for nutritive value in Digitaria milanjiana. 3. Relation of chemical composition and morphological and anatomical characteristics to the difference in digestibility of divergently selected full sibs, and comparison with D. eriantha ssp. pentzii

Comparisons were made of the dry matter digestibility (DMD) and yield of plant fractions harvested from long-established swards of 6 genotypes of Digitaria milanjiana selected from 3 F1 families for high and low leaf digestibility, and D. eriantha ssp. pentzii (pangola grass). Defined leaf blade, sheath and stem internode fractions were collected at different sward development stages and analysed for DMD, chemical composition, and tissue morphological and anatomical characteristics. The leaf blade of each high-digestibility genotype was consistently superior (1.9-4.5 percentage units) in DMD to that of its low digestibility counterpart, and to pangola grass, at both vegetative and reproductive -- stages. For leaf sheath and stem, the superiority in DMD of the high digestibility group was not evident or was less pronounced. The high DMD selections had green leaf dry matter yields comparable to those of the low DMD group but higher than those of pangola grass. The gain in DMD for leaf blade of the high over the low digestibility selection was consistently correlated with a decrease in cell wall content, acid detergent fibre or lignin, and poorly correlated with other chemical and leaf morphological characteristics. High and low DMD genotypes did not differ in the proportion of cell types in leaf or stem, or in other measured anatomical characteristics.

Effect of feeding some plant foods as source of dietary fibre on biological utilisation of diet in rats

Isoproteinous diets containing 1% cholesterol and 10% fibre derived from plant foods namely, peepalbanti (Ficus religiosa), barbanti (Ficus bengalensis), gullar (Ficus glomerata), teent (Capparis decidua) and khejri beans (Prsopsis cineria) or pure cellulose, were fed to rats for 40 days. Effect of incorporation of these whole plant parts on feed intake, weight gain, feed efficiency ratio (FER), dry matter digestibility (DMD) and true protein digestibility (TPD) in weanling rats was studied. Their inclusion did not affect the weight gain significantly whereas all other parameters were influenced to a varying extent. Foods rich in lignin had relatively lower FER, DMD and TPD whereas cellulose and pectin rich foods had higher DMD and TPD.

The effect of continuous and rotational grazing of sourveld on the selection of plant fractions by simmentaler heifers

Abstract In a grazing trial conducted at the Kokstad Agricultural Research Station, the selection of six plant fractions by cattle grazing sourveld was investigated. Relations between the selectivity of the cattle and the dry matter digestibility (DMD) and crude protein (CP) content of these fractions were examined. The effects of continuous and six‐paddock rotational grazing (each at 1,0 and 2,3 animals/ha) on selectivity were examined. In general, cattle preferentially selected the glabrous foliar components, which constituted 31,3 % of herbage on offer and had the highest DMD (56 %) and CP content (5,77 %) of the grass fractions. With the exception of broad hairy leaves, rejection of the other components appeared to be primarily related to their lower nutritive value. Rotational grazing per se did not significantly decrease selectivity. In the heavily stocked, rotational grazing treatment cattle consumed a greater proportion of the stem fraction but rejected more of the hairy leaves than in the other treatments. It was thus concluded that cattle continued to graze selectively regardless of the grazing method or the stocking intensity.

The digestibility by sheep and goats of five roughages offered alone or with concentrates

SUMMARYThe digestive efficiency, rumen fermentation pattern, nitrogen balance, water intake and urine excretion were compared using four mature vasectomized Chios rams and four Damascus goats for each of five roughages (barley, lucerne or sudax hay, barley straw and leaves and twigs of acacia) offered alone or with concentrates (1:1 ratio), at approximately the maintenance energy level.There were no species differences in the apparent digestibility of nutrients when the roughages were offered alone except for the significantly higher digestibility of dry matter, organic matter (OM), and gross energy (GE) of straw by goats. Sheep exceeded goats significantly in the digestibility of D.M., OM, GE and crude protein (CP) of lucerne hay plus concentrate and of CP when barley hay or sudax hay were supplemented with concentrate.Compared with sheep, goats tended to consume more D.M. per kg W0·75 and drink less water and excrete less urine, but significant differences for water were obtained only with barley straw plus concentrate and for urine with barley hay and acacia.Daily protein retention (g/kg W0·75) was consistently lower in goats than sheep but significant difference was obtained with acacia and with lucerne hay or straw plus concentrate. These results would suggest that Damascus goats require more protein for maintenance than sheep.Compared with sheep, goats had significantly higher rumen NH3·N concentration with both acacia diets but lower with lucerne hay.Total VFA concentration tended to be higher in sheep with all diets, but significance was observed only with barley hay although rumen pH was lower (acacia diets) or similar compared with goats. The molar proportion of acetic was significantly higher in sheep than goats with barley hay plus concentrate. Goats exceeded sheep significantly in the proportion of propionic with straw, of butyric with both barley hay and sudax hay plus concentrate diets, and of isobutyric with barley hay or acacia plus concentrate; with the other diets goats tended to have higher proportions of butyric and isobutyric.

Nutritive Value of Oatlage, Barley/Pea, Pea, Oat/Pea, Pearl Millet, and Sorghum as Silage Ground under a Double Cropping Forage System for Dairy Heifers

Feeding value of cool season (oatlage, barley/pea, pea, oat/pea) and warm season (pearl millet and sorghum) silages for dairy heifers was determined utilizing a double cropping forage system. Cell wall and crude protein concentrations were inverse due to delayed harvesting of cool season forages. Cell wall content increased 20.6 percentage units and crude protein decreased 7.0 percentage units between June 22 and July 6, 1983, as oat/pea silage advanced from early head to early dough stage. Average dry matter yield was lowest for sorghum and highest for oat/pea silage. Holstein heifers offered pea silage had greater dry matter consumption (2.6% of body weight) and higher dry matter digestibility (64.8%) than from the other silages. However, heifers consumed more dry matter of warm season forages.Acid detergent lignin concentrations in double crop forages had a higher correlation with dry matter digestibility than dry matter intake while neutral detergent fiber, acid detergent fiber, and crude protein content were better correlated with dry matter intake than dry matter digestibility. Heifers fed warm season forages had higher molar percentages of acetate but had lower molar percentages of propionate, butyrate, and valerate compared with cool season forages. Acetate-to-propionate ratio was similar between pearl millet and sorghum silage.

Urea Levels and Supplemental Energy Sources in Sugarcane Diets

Two experiments, each involving a digestion-N balance trial and a feedlot trial, determined the replacement value of urea-corn meal (UC) for cottonseed meal (CSM) and the value of molasses in sugarcane diets. Steers fed 70% sugarcane-30% concentrate diets with 0, 28 or 56% of the dietary N as urea had a slight reduction (P<.28) in dry matter (DM) intake and an increase (P<.01) in crude protein digestibility as dietary urea increased. Urea level did not affect the digestibility of other dietary components. Urea N appeared to be utilized less efficiently than CSM N. In the feedlot, steers were fed 71% sugarcane-29% concentrate diets with 0, 25 or 50% of the dietary N as urea during a 93-d growing phase, then 39.5% sugarcane-60.5% concentrate diets with 0, 20 or 40% of the dietary N as urea, respectively, during a 63-d finishing phase. Growing steers fed urea gained slower (P<.01), consumed less DM and required more DM/kg of gain (P<.05). Dietary urea level did not affect gain, DM intake or DM utilization during finishing, nor did it affect carcass quality. Steers fed 70% sugarcane-30% concentrate diets, with urea and CSM as N supplements and molasses and corn as energy supplements to the high-urea diet, had higher DM digestibility (P<.01) for the urea-molasses (UM) supplemented diet than for the CSM diet. Digestibilities of all components of the UM and UC diets were similar. Retention of N was similar for steers fed the UC and CSM diets, but both groups retained more N than steers fed the UM diet. In the feedlot, steers fed the UM diet gained slower (P<.01) with lower efficiency than steers fed the CSM or UC diets. Performance of steers fed CSM or UC diets was similar. This study showed that urea was inferior to CSM as a crude protein source in sugarcane diets, especially when molasses was used as an energy supplement.

Forage Yield and Quality of Brassicasp. Established Using Preemergence Herbicides1

abstractBrassica sp. may serve as high energy forage crops at times when forage availability may be limited. Field studies were conducted in the Northeast to assess forage yield and quality of 'Sirius' turnips (Brassica rapa L.) and 'Perko' rape (B. napus L.) planted on a Hagerstown silt loam (fine, mixed, mesic Typic Hapludalf) soil in late May (1978) and late April (1979). Preemergence herbicides including metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐ l‐methylethyl) acetamide], pendimethalin [Nl‐ethylpropyl)‐3,4 dimethyl‐2,6‐dinitrobenzeneamine], and nitrofen [2,4‐dichlorophenyl p‐nitrophenyl ether] were applied alone and in various combinations to determine effectiveness in reducing weed competition. Forage yields of turnips and rape 100 days after seeding were generally not affected by the herbicide treatments. However, associated weed yields in both turnips and rape were significantly reduced with all herbicide treatments applied. Pendimethalin applied at 2.2 kg ha−1was phytotoxic to both turnips and rape reducing yields 67 and 17%, respectively, as compared to the untreated control. Forage dry matter yields of turnips and rape with adequate weed control were as high as 5068 and 6711 kg ha−1, respectively. In 1978, turnip whole plant crude protein (CP) concentration was highest (227 g kg−1) where pendimethalin was applied at 2.2 kg ha−1. The 2nd year CP levels for turnip leaves were similar for all herbicide treatments, but root levels were highest where pendimethalin at 2.2 kg ha−1was used. The high rate of pendimethalin severely inhibited root development resulting in smaller roots with higher CP. Rape CP levels in 1978 were generally highest where herbicides were used, but in 1979, rape CP was not affected by herbicide application. Averaged across herbicide treatments, turnip (whole plant) and rape CP levels averaged 121 and 106 g kg−1, respectively. In vitro dry matter disappearance for turnips and rape were similar averaging 898 g kg−1and were not affected by herbicide application. Results indicate that appropriate preemergence herbicides will reduce early season weed competition and will enhance early production of turnips and rape. The high production potential and the high dry matter digestibility 100 days after seeding warrant consideration of turnips and rape for use as supplemental summer forage crops.

Effects of Diet, Dry Matter Level and Sodium Hydroxide Treatment on the Ensiling Characteristics and Utilization by Lambs of Cattle Waste-Rye Straw Mixtures

A 2 × 3 × 2 factorial arrangement of treatments was used to study the effect of diet, dry matter level and sodium hydroxide (NaOH) on the ensiling characteristics of cattle waste and rye straw mixtures. Waste collected from cattle fed high roughage or high concentrate diets was mixed with ground rye straw in a ratio of 60:40, wet basis. Mixtures were adjusted with water to 30, 40 or 50% dry matter and were treated with 0 or 4% NaOH, dry basis, prior to ensiling. Untreated silages exhibited more (P<.01) desirable fermentation characteristics, as measured by pH, lactic acid and water soluble carbohydrate content. Ensiling eliminated coliforms and Proteus organisms in untreated silages but not in NaOH-treated silages. In a digestibility trial with lambs, silages containing waste collected from cattle fed high concentrate diets had higher dry matter digestibilities (P<.01) than silages containing waste from cattle, fed a high roughage diet. Treatment with NaOH increased dry matter and organic matter digestibilities (P<.01) but decreased crude protein digestibility (P<.01). Dry matter level did not affect dry matter digestibility.

Utilization of Micronized Sorghum Grain by Dairy Calves

Forty-two heifers (24 Holsteins and 18 Ayrshires) were used to compare utilization of rations containing 60% dry rolled and micronized sorghum grain. Calves within each breed were assigned to three groups: (a) control (dry rolled), (b) micronized (380 g/liter), and (c) micronized (230 g/liter). During an 8-wk trial, weights were recorded weekly and rumen samples for volatile fatty acid determination were taken 4 to 5h after feeding during the 4th wk. Nine bull calves (six Holsteins and three Ayrshires) were in a 3×3 Latin square design to determine digestibility of rations in the heifer trial. Mean weight gains were 46.9, 46.0, and 43.8kg for heifers fed dry rolled, micronized (380 g/liter), and micronized (230 g/liter) sorghum grain. Average feed intake was higher in the group of heifers fed the dry rolled grain ration, i.e., 164.7kg compared to 150.0 and 142.4kg for the above groups fed micronized grain. There was a trend for greater feed efficiency by calves fed micronized grain which was consistent with slightly higher digestibility of dry matter and organic matter in the micronized rations. Micronized sorghum grain was accepted readily by young dairy calves.

The effect of experimental variation in the quantity of pancreatic secretion on the digestion and utilization of milk-substitute diets by the calf.

1. Apparent digestibility, apparent absorption and nutrient-balance studies were made with two Ayrshire and three Friesian calves given milk-substitute diets. Cannulas were inserted into the duodenum of the calves at about 21 d old, so that the quantity of pancreatic secretion entering the duodenum could be varied.2. After cannulation, there was a significant reduction in the apparent digestibility of the dry matter, organic matter, crude protein and fat, and in the apparent absorption of calcium and phosphorus from a milk-substitute diet containing ‘mildly’ pre-heated, spray-dried skim-milk powder. The amounts of nitrogen and P retained by the calves were also significantly reduced.3. Collection and removal of the pancreatic secretion for a period of 12 h/d resulted in a further significant reduction in the apparent digestibility of the dry matter, organic matter and crude protein of the milk-substitute diet.4. At 77 d of age, there was no significant effect on the nutrient balance or on the digestibility of a diet containing a ‘severely’ pre-heated, spray-dried skim-milk powder when the normal secretion of the pancreas was supplemented for 12 h/d with additional pancreatic secretion collected from the same calf.5. Friesian calves, in comparison with Ayrshires, tended to have a higher digestibility of dry matter, organic matter and fat, apparent absorption of Ca and P and retention of N, Ca and P. These differences were apparent both before and after the calves were cannulated.

ORGANIC ACID TREATMENT OF HAY

Orchard grass, alsike clover, and an alfalfa–brome mixture were field treated before baling with either formic acid, acetic acid, propionic acid, ChemStor, or HaySavor at levels between 0.05–0.11% on a fresh weight basis. The temperature of the untreated orchard grass hay was 137 F (58 C) and mold was visible after 3 days; formic acid-treated orchard grass hay was 102 F (39 C) and showed traces of mold; no mold was visible in the ChemStor-treated orchard grass bales and temperature was 91 F (33 C). Acetic acid treatment seemed to encourage mold growth in alsike clover hay over 30% moisture at the time of baling. Dry matter (DM) intake by sheep was significantly higher (P &lt; 0.05) for the untreated hay compared with the propionic acid-treated alfalfa–brome hay. The lowest intake was with the formic acid-treated hay. Acid treatment did not significantly affect (P &gt; 0.05) the DM digestibility of the alfalfa–brome hay, although the untreated hay had a higher DM digestibility than the acid-treated hay in the same treatment square.

The effect of age and method of haymaking on the digestibility and voluntary intake of the forage legumes Dolichos lablab and Vigna sinensis

Cowpea sown in January and harvested in April had a higher dry matter digestibility and voluntary intake in comparison with Dolichos. When field cured for 20 days, differences in digestibility and voluntary intake were not significant between species, and levels of both were markedly reduced. Intermediate levels for digestibility and voluntary intake were obtained after field curing for 8 days. Dry matter digestibility of Dolichos declined at subsequent first growth harvests in May, July, and August but voluntary intake for the April, May, and August cuts was similar.