GENETIC VARIATION FOR FORAGE QUALITY OF ALFALFA STEMS

1987 ◽  
Vol 67 (4) ◽  
pp. 1057-1067 ◽  
Author(s):  
D. R. BUXTON ◽  
G. C. MARTEN ◽  
J. S. HORNSTEIN

When normally harvested for hay, the basal portion of alfalfa (Medicago sativa L.) stems is low in forage quality. This study was conducted to determine whether genetic variation for in vitro digestible dry matter (IVDDM) and crude protein (CP) concentration of stems of perennial Medicago spp. could be identified and whether morphological and chemical traits were associated with variation in these characteristics of stems. The lower six nodes and internodes of stems and total herbage from 64 Plant Introduction (PI) accessions and five cultivars of field-grown plants were harvested twice when most plants were at the early seed-pod stage of maturity. Several morphological and growth traits were measured, and both stems and total herbage were evaluated for IVDDM and CP concentration. Covariant analysis was used to adjust in IVDDM and CP concentration of stems for differences in plant maturity. Significant variation for IVDDM and CP concentration in stems existed among the cultivars and among the accessions. Some accessions had significantly higher stem IVDDM or CP concentration than control cultivars. The M. sativa accession, PI 440496, had the fourth highest stem IVDDM and third highest stem CP, with concentrations of 374 and 79 g kg−1, respectively. The number of ridges on stems (stem shape) was significantly correlated with stem IVDDM and CP concentration with average correlation coefficients of 0.30 and 0.35, respectively. Cell-wall concentration and lignin concentration per unit cell wall of stems were both negatively correlated with stem IVDDM and CP concentration. Selection for improved nutritive value of stems may have potential for improving the nutritive value of alfalfa herbage.Key words: Alfalfa, forage quality, crude protein, in vitro digestibility, Medicago sativa L.

2004 ◽  
Vol 44 (8) ◽  
pp. 763 ◽  
Author(s):  
K. F. Smith ◽  
R. J. Simpson ◽  
R. N. Oram

The effects of site and season on the nutritive value of 16 perennial ryegrass cultivars and 60 half-sib families were assessed at 2 locations in South West Victoria. Crude protein, water-soluble carbohydrates, neutral detergent fibre and in vitro digestibility were measured on vegetative herbage, harvested in either autumn or spring. While no heritable genetic variation for nutritive value parameters was detected in this set of families, consistent differences in the nutritive value of cultivars were measured across sites and seasons. The cultivars Yatsyn1 and Ellett were consistently high in both water-soluble carbohydrates and in vitro digestibility. The differences in mean nutritive value between high and low ranking cultivars were ~40 g/kg water-soluble carbohydrates and 3–5% in vitro digestibility. These consistent differences in forage quality demonstrate the value of measuring forage quality during cultivar evaluation. The identification of cultivars with improved nutritive value will also facilitate the crossing of the alleles that confer this improvement into other genetic backgrounds.


1972 ◽  
Vol 52 (6) ◽  
pp. 941-948 ◽  
Author(s):  
L. B. MacLEOD ◽  
H. T. KUNELIUS ◽  
F. W. CALDER

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.


1967 ◽  
Vol 47 (2) ◽  
pp. 161-167 ◽  
Author(s):  
S. Smoliak ◽  
L. M. Bezeau

Five native grasses and one sedge of the Stipa-Bouteloua prairie, three introduced grasses collected at five stages of growth, and four shrubby species collected at three stages of growth were analyzed for proximate chemical constituents.The amounts of phosphorus and digestible and crude protein of all species decreased with maturity, while the cellulose increased. Introduced grasses generally contained more crude protein than native grasses. Shrubby species were higher in crude protein and phosphorus than native grasses. No consistent trend was observed in relative total ash and calcium content at progressive stages of development. The estimated nutritive value index was high for all grasses and low for two Artemisia species. The seasonal declines in crude protein and phosphorus suggest that protein and phosphorus supplements are desirable for range cattle during the fall, winter, and early spring.


1992 ◽  
Vol 55 (1) ◽  
pp. 29-34 ◽  
Author(s):  
P. Kamatali ◽  
E. Teller ◽  
M. Vanbelle ◽  
G. Collignon ◽  
M. Foulon

AbstractLeaves of Leucaena leucocephala, Sesbania sesban and Calliandra callothyrsus were harvested in Rwanda from young shoots at 8 weeks after the first cutting. They were dried, ground and incubated at the same time in polyester bags in three non-lactating Holstein-Friesian cows each fitted with a ruminal cannula. The bags were removed at 0, 2, 4, 8, 24, 48, 72 and 144 h after the start of incubations. The different parameters characterizing extent and rate of ruminal degradation of organic matter (OM), neutral-detergent fibre (NDF), and crude protein (CP) were calculated. In vitro digestibility of residual protein after 24 h and 48 h incubation was also determined. Sesbania sesban had lowest cell wall contents and gave highest ruminal degradability for OM, NDF and CP. Leucaena leucocephala was degraded to a lesser extent, but its undegraded protein had a somewhat higher in vitro digestibility. In contrast, protein of Calliandra callothyrsus was poorly degraded and digested. The proportion and composition of cell wall could not explain these differences in digestion characteristics and other measurements, such as tannins, were incriminated. Increased ruminal incubation time augmented the extent of ruminal degradation and reduced in vitro digestibility of undegraded protein but did not affect the undigestible protein fraction.


1969 ◽  
Vol 20 (4) ◽  
pp. 643 ◽  
Author(s):  
RJ Clements

In a highly variable breeding population of P. tuberosa, marked responses were obtained to three generations of selection for high and low crude protein concentration (percentage nitrogen x 6.25) in whole tillers at heading. Total response was similar in each direction, and realized heritability estimates were h2 = 0.25 and h2 = 0.20 in the high and low directions respectively. The responses were accompanied by positively correlated changes in in vitro digestibility and in characters commonly used as indicators of nutritive value of herbage. However, there were large negatively correlated changes in seedling vigour, relative growth rates, and other morphological and physiological characters. The implications of the results for pasture plant breeding are discussed.


1991 ◽  
Vol 71 (1) ◽  
pp. 87-96 ◽  
Author(s):  
W. D. Willms ◽  
K. A. Beauchemin

An experiment was conducted to determine the qualitative response of rough fescue (Festuca scabrella var. campestris) and Parry oat grass (Danthonia parryi) to five cutting frequencies and three cutting heights Beginning in mid-May, the same plants were cut every 1, 2, 4, 8, or 16 wk. during a 16-wk period, at heights of either 5, 10, or 15 cm above ground level. The treatments were repeated in 3 consecutive years on the same plants. Crude protein (CP), lignin, and calcium (Ca) were significantly greater for Parry oat grass than for rough fescue, which had greater acid detergent fiber (ADF) and phosphorus (P) concentrations. Increasing cutting frequency in the first year reduced acid detergent-insoluble nitrogen (ADIN), ADF, and lignin but increased CP and in vitro digestibility of dry matter (IVD) in both forages. Repeated treatment over 3 yr tended lo increase ADF and Ca but reduce CP, P, and IVD. In the first year of treatment, CP yields in rough fescue and Parry oat grass were greatest with 2 or 4 cuts during the growing season. However, in the second year of treatment, CP yield was greatest with one or two cuts in rough fescue and with four cuts in Parry oat grass. The data confirm the benefits of repeated grazing within a year to maintain high quality forage but demonstrate the need to limit the frequency of repeated grazing to avoid deterioration and maximize nutrient yield. Nutrient yields and, presumably, benefits to livestock would be greater at a lower grazing frequency on rough fescue than on Parry oat grass. Key words: Festuca scabrella var. campestris, Danthonia parryi, crude protein, acid detergent fiber, in vitro digestibility, forage quality


1992 ◽  
Vol 6 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Douglas J. Doohan ◽  
Gilles Belanger ◽  
Russ R. King ◽  
Jerry A. Ivany

Fluazifop-P, applied in the spring or fall and pronamide, applied in the fall only, reduced quackgrass infestation in established alfalfa and increased the dry matter yield of alfalfa. Herbicides did not improve alfalfa in vitro digestibility or crude protein content. Average residues of fluazifop-P in alfalfa treated with rates of 0.25 or 0.5 kg ai ha–1, were 0.1 mg kg–1when harvested 280 d after application, and 0.06 mg kg–1when harvested 295 d after application. Average residues in alfalfa harvested 41 and 55 d after application were 0.13 mg kg–1and 0.1 mg kg–1, respectively, with a 0.25 kg ha–1treatment and 0.19 mg kg–1and 0.05 mg kg–1, respectively, with a 0.5 kg ha–1treatment.


Crop Science ◽  
1994 ◽  
Vol 34 (6) ◽  
pp. 1672-1678 ◽  
Author(s):  
J. P. Lundvall ◽  
D. R. Buxton ◽  
A. R. Hallauer ◽  
J. R. George

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