CAUSAL EFFECTS AMONG FORAGE YIELD AND QUALITY MEASURES OI SMOOTH BROMEGRASS

1986 ◽  
Vol 66 (3) ◽  
pp. 591-600 ◽  
Author(s):  
M. D. CASLER
Keyword(s):  
Cell Wall ◽  
Path Analysis ◽  
Indirect Effects ◽  
Crude Protein ◽  
Dry Matter ◽  
Bromus Inermis ◽  
Forage Yield ◽  
Smooth Bromegrass ◽  
Dry Matter Digestibility

Future improvement of forage quality in smooth bromegrass (Bromus inermis Leyss.) and other species will require a knowledge of the chemical and structural factors most limiting to digestibility and intake of dry matter by ruminants. The objective of this study was to estimate direct and indirect effects from path analysis of several forage constituents on in vitro dry matter digestibility (IVDMD) and forage yield of smooth bromegrass. Six hundred and fifteen spaced plants of B8HD smooth bromegrass were harvested at Arlington, Wis. in June 1982 to assess dry matter yield and forage constituents. Near-infrared reflectance (NIR) spectroscopy was used to estimate IVDMD, crude protein, neutral detergent fiber, acid detergent fiber, cellulose, acid detergent hemicellulose, acid detergent lignin, and ash based on a random calibration subset of 75 plants. Five independent variables comprised the path analysis model: crude protein, cellulose, hemicellulose, lignin, and ash. None of the variables directly or indirectly affected forage yield. Lignin and cellulose concentrations had the overwhelmingly largest direct effects on IVDMD, while hemicellulose was important only when expressed as a percentage of the cell wall. Crude protein was important, but only to a small extent, while ash had no effect on IVDMD. The largest indirect effects on IVDMD were generally indirect effects of each character through correlated changes in lignin and indirect effects of lignin through correlated changes in other characters. The large effects of lignin support previous work establishing lignin as the primary factor limiting IVDMD. The importance of cellulose compared to hemicellulose, a result contrary to many current theories on the role of cell walls in rumen digestion, emphasizes at least three factors contributing to differences between this study and previous studies: (1) species differences, (2) genetic vs. species and maturity effects, and (3) analytical procedures. Current evidence suggests a cell wall ideotype should have reduced cellulose and lignin with either reduced or unchanged hemicellulose concentration.Key words: Bromus inermis Leyss., cellulose, hemicellulose, in vitro dry matter digestibility, lignin, forage yield

scholarly journals Agronomic Comparison and In Vitro Dry Matter Digestibility of Eight Sorghums at Two Locations in Puerto Rico.

1969 ◽  
Vol 70 (1) ◽  
pp. 37-44
Author(s):  
Salvio Torres-Cardona ◽  
Antonio Sotomayor-Ríos ◽  
Fred Miller
Keyword(s):  
Puerto Rico ◽  
Leaf Area ◽  
Crude Protein ◽  
Dry Matter ◽  
Matter Content ◽  
Forage Yield ◽  
Dry Matter Content ◽  
High Positive Correlation ◽  
Dry Matter Digestibility

Eight sorghum (Sorghum bicolor L. Moench) genotypes were evaluated during four consecutive 60-day cuttings at two locations in Puerto Rico. Differences between genotypes and cuttings were significant for the eight traits studied (green forage yield, content and yield of dry matter and crude protein, in vitro dry matter digestibility, plant height and leaf area). The location x genotype interaction was significant for most traits except dry matter content and in vitro dry matter digestibility (IVDMD). At both locations the best dry forage producers over the 240-day period were ATx623 x Rio and ATx623 x TMTx430 with 34 and 30 t/ha, respectively, al Isabela; and 20 and 19 t/ha, respectively at Mayagüez. Average IVDMD and crude protein values of hybrids were 58 and 10.2%, respectively. Rio was lowest in dry forage yield but highest in IVDMD value: 62%. Leaf area had a high positive correlation with the three yield criteria. A rough estimate of net profit from growing forage sorghum in Puerto Rico for milk production is $1,211/ha.

scholarly journals Production of alfalfa hay under different drying methods

2010 ◽  
Vol 39 (8) ◽  
pp. 1676-1683 ◽  
Author(s):  
Marcela Abbado Neres ◽  
Deise Dalazen Castagnara ◽  
Eduardo Eustáquio Mesquita ◽  
Maximilliane Alavarze Zambom ◽  
Leiliane Cristine de Souza ◽  
...  
Keyword(s):  
Cell Wall ◽  
Crude Protein ◽  
Dry Matter ◽  
In Vitro Digestibility ◽  
Drying Methods ◽  
Drying Process ◽  
Dry Matter Digestibility ◽  
Alfalfa Hay ◽  
Number Of Leaves

This trial aimed at determining the dehydration curve at nine times (0, 3, 6, 9, 24, 27, 30, 33 and 46 hours after cuting of the plants); the leaf/stem ratio and number of leaves per stem in alfalfa submitted to four managements during the drying process. It was also evaluated the bromatologic composition and in vitro digestibility of the dry matter and cell wall of alfalfa hay before storage. The drying methods applied for alfalfa were the following: drying in the field until 50% DM and drying conclusion in an airy shed; drying in the field without turning; drying with only one turning and drying with two turnings. The experimental design was completely randomized with four drying methods and five replications. Leaf dehydration was faster when compared to the stems in all drying methods. Drying in the shed promoted the lesser re-hydration of the plants at night due to dew. It was also verified that alfalfa hays that remained under the sun and were turned showed the worst quality with reduction in crude protein contents and increase in NDF, ADF, NDIN and ADIN. However, in vitro dry matter digestibility and cell wall digestibility did not suffer any alteration because of the different dehydration methods (69.79 and 41.39%, respectively). There is a market fall of leaves and a reduction on the number of leaves per stem with the turnings.

Divergent Selection for In Vitro Dry Matter Digestibility in Smooth Bromegrass 1

Crop Science ◽  
1986 ◽  
Vol 26 (6) ◽  
pp. 1123-1126 ◽  
Author(s):  
N. J. Ehlke ◽  
M. D. Casler ◽  
P. N. Drolsom ◽  
J. S. Shenk
Keyword(s):  
Dry Matter ◽  
Divergent Selection ◽  
Smooth Bromegrass ◽  
Dry Matter Digestibility ◽  
Selection For

EFFECT OF STRUCTURAL AND CHEMICAL FACTORS OF FORAGES ON POTENTIALLY DIGESTIBLE FIBER, INTAKE, AND TRUE DIGESTIBILITY BY RUMINANTS

1988 ◽  
Vol 68 (3) ◽  
pp. 787-799 ◽  
Author(s):  
V. GIRARD ◽  
G. DUPUIS
Keyword(s):  
Cell Wall ◽  
Dry Matter ◽  
Plant Cell Wall ◽  
Neutral Detergent Fiber ◽  
Optimum Number ◽  
Apparent Digestibility ◽  
Cool Season ◽  
Dry Matter Digestibility ◽  
True Digestibility

In view of the large variation found in plant cell wall digestibilities with ruminants, an attempt was made to group 124 feeds into different lignification classes (clusters) on the basis of chemical characteristics. Each feed cluster was described using a structural coefficient [Formula: see text] that related the potentially digestible fiber (PDF, %) to the ratio between lignin and cell wall volume. The optimum number of clusters was determined iteratively by performing a regression of the apparent digestibility of dry matter at maintenance level (DDM1, %) against the PDF and cell soluble (SOL, %) contents of feeds. The [Formula: see text] coefficients varied from 0.05 (grains, N = 13) to 1.85 (corn silage, N = 3) and increased with the maturity of the grasses from 0.88 (legumes, vegetative cool season grasses, N = 26) to 1.33 (mature, cool season grasses, N = 19). Predicted PDF were closely correlated (r > 0.9, P < 0.01) to in vitro cell wall disappearances (IVCWD). Apparently digestible cell wall in four grasses and four legumes increased linearly with 96-h IVCWD and standard error (SE) was similar to the SE of predicted apparent digestible SOL from SOL concentrations. Assuming that similarity between SE could be also observed in larger samples, PDF and SOL were used in summative equations to predict apparent dry matter digestibility. DDM1 discounted for intake (DDM1 – 4, %) was regressed against SOL and PDF concentrations of 87 feeds:[Formula: see text]with ds and df, the true digestibilities of SOL and PDF. Estimates of ds and df were 0.98 and 0.95 for a zero-production (maintenance) level of intake, and 0.91 and 0.79 for an intake level four times maintenance. Since the true digestibility of the PDF component was only 4% – 13% lower than that of the cell soluble component, the concentration of PDF in cell wall was the major determinant in the variation in apparent digestibility of forages. Key words: lignin, neutral detergent fiber, true digestibility, cluster analysis, feeds

EFFECTS OF EARLY SUMMER AND FALL CUTTING MANAGEMENT ON DRY MATTER YIELDS, DIGESTIBILITY, CRUDE PROTEIN, AND SURVIVAL OF SARANAC AND NARRAGANSETT ALFALFAS

1972 ◽  
Vol 52 (6) ◽  
pp. 941-948 ◽  
Author(s):  
L. B. MacLEOD ◽  
H. T. KUNELIUS ◽  
F. W. CALDER
Keyword(s):  
Medicago Sativa ◽  
Crude Protein ◽  
Dry Matter ◽  
Early Summer ◽  
Good Survival ◽  
Considerable Decrease ◽  
Dry Matter Digestibility ◽  
Medicago Sativa L ◽  
Cutting Management

The effects of early summer and fall cutting managements on two alfalfa (Medicago sativa L.) cultivars were studied over a 3-year period. Removal of the first crop of Saranac and Narrangansett alfalfas at prebud stage, followed by two cuts at the early bloom stage before early September, and a late fall harvest on October 25, produced seasonal dry matter (DM) yields of 7.5–8.6 metric T/ha in the 1st year. Stand deterioration, however, was severe and by the 3rd year, practically all alfalfa had disappeared. Average percent crude protein (CP) in cut 1 was 17.7–21.9 and percent in vitro dry matter digestibility (IVD) 67.4–73.8. Removal of the first cut at bud stage with two subsequent harvests at the early bloom stage also allowed a total of three harvests before early September and resulted in seasonal DM yields of 8.6–8.8 in the 1st year. Although the survival of alfalfa was increased over the managements where cut 1 was at prebud stage, a considerable decrease of alfalfa was still observed in the 3rd year. Under this management, average CP in cut 1 was 15.8–16.3 and IVD 64.1–68.4. Harvesting the first crop at early to midbloom stage and the second crop at early bloom in early to mid-August, followed by third harvest in late October, resulted in good survival with seasonal DM yields of 6.1–10.6. Lower CP and IVD were recorded in cut 1 than in the more intensive managements. Under all managements, average CP in cuts 2 and 3 was 14.9–17.3 and 13.3–19.4, respectively. IVD was 54.5–60.7 in cut 2 and 56.0–64.4 in cut 3.

scholarly journals Effect of seedbed methods and time of harvest on the yield and nutritive value of some forage crops grown on Vertisol at Debre Zeit, Ethiopia

1992 ◽  
Vol 1 (5) ◽  
pp. 491-497
Author(s):  
Abate Tedla ◽  
Helena Airaksinen ◽  
M. A. Mohamed-Saleem
Keyword(s):  
Avena Sativa ◽  
Crude Protein ◽  
Dry Matter ◽  
Nutritive Value ◽  
Dry Matter Yield ◽  
Lablab Purpureus ◽  
Forage Crops ◽  
Dry Matter Digestibility ◽  
Time Of Harvest

The influence of the improved drainage broadbed and furrow (BBF), as opposed to the traditional flat seedbed over the growing season on the dry matter yield and nutritive value of Avena sativa, Vigna unguiculata, Lablab purpureus, Vida dasycarpa, Trifolium steudneri and Sesbania sesban were studied on Vertisol. Up to 7 t/ha dry matter yield was recorded for Avena sativa and Lablab purpureus when planted on Vertisols with improved drainage. Dry matter yield of forage crops also increased with advance in stage of maturity or subsequent harvests. On both improved and traditional flat seedbed methods, the chemical analysis of forage crops showed similar declines in crude protein content and in vitro dry matter digestibility (IVDMD) levels as the maturity of forage crops progressed.

Dry matter intake, nutrient selection and milk production of dairy cows grazing rainfed perennial pastures at different herbage allowances in spring

1999 ◽  
Vol 39 (8) ◽  
pp. 923 ◽  
Author(s):  
P. J. Moate ◽  
D. E. Dalley ◽  
J. R. Roche ◽  
C. Grainger
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Crude Protein ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Neutral Detergent Fibre ◽  
Dry Matter Digestibility ◽  
Herbage Intake ◽  
Selection Differentials

Summary. The effect of herbage allowance (20, 30, 40, 50, 60 and 70 kg DM/cow. day) on the consumption of nutrients from herbage and milk production by cows in early lactation, was examined. The experiment was conducted on rainfed perennial ryegrass pastures in September and October 1997 in south-eastern Victoria, Australia. The herbage on offer comprised 64% perennial ryegrass, 21% other grasses, 1% white clover, 5% weeds and 9% dead material on a dry matter (DM) basis. The average pregrazing herbage height was 13 cm, at an estimated pregrazing herbage mass of 3.6 t DM/ha. The herbage on offer was of high quality containing 11.6 MJ metabolisable energy/kg DM, 202 g crude protein/kg DM and 525 g neutral detergent fibre/kg DM. Concentrations of calcium, magnesium, sodium, potassium, phosphorus, sulfur and chloride were 4.4, 2.2, 4.4, 31.2, 3.5, 2.7 and 11.4 g/kg DM, respectively. As daily herbage allowance per cow increased, dry matter intake increased curvilinearly (P<0.01) from 11.2 to 18.7 kg DM/cow. day. This was associated with a decrease in utilisation of herbage from 54 to 26% and an increase in milk production from 25.9 to 29.1 kg/cow. day. The cows on all treatments grazed for less than 8.7 h/day. The increase in intake was achieved by an increase in the rate of herbage intake from 1.5 to 2.2 kg DM/h for herbage allowances of 20 and 70 kg/cow.day, respectively. Irrespective of herbage allowance, cows selected a diet that was approximately 10% higher in in vitro dry matter digestibility and 30% higher in crude protein than that in the herbage on offer. The neutral detergent fibre content of the herbage selected was lower (P<0.05) than that on offer. The herbage consumed contained more (P<0.05) magnesium, potassium and sulfur, the same amount of calcium and phosphorus and less (P<0.05) sodium and chloride than the herbage on offer. For rainfed perennial pastures in spring, herbage allowance is an important factor in determining voluntary feed intake and production of dairy cows. To achieve 30 L from herbage, without supplementation, high herbage allowances are required. The increase in herbage intake, with increasing herbage allowance, resulted from an increase in rate of dry matter intake and not an increase in grazing time. No relationship was evident between herbage allowance and the selection differentials for in vitro dry matter digestibility, crude protein and neutral detergent fibre. Selection differentials for rainfed perennial pastures in spring are similar to those reported for irrigated perennial pastures in northern Victoria in spring and autumn. When determining nutrient requirements it is important to consider the interaction between herbage intake and nutrient concentration in the herbage.

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