Summer forages under irrigation. 2. Forage composition

1985 ◽  
Vol 25 (2) ◽  
pp. 402 ◽  
Author(s):  
DK Muldoon

Summer forages, including Sorghum bicolor hybrids, S. sudanense, S. bicolor x S. sudanense hybrids, perennial sorghum, maize and Pennisetum and Echinochloa millets, were grown on an alkaline clay soil at Trangie, New South Wales. Primary growth was sampled every 3 weeks and the plant components analysed for nitrogen, sulfur, sodium and in vitro dry matter digestibility. Whole plants were analysed for calcium, magnesium, phosphorus, potassium and chloride content. Fresh leaf samples were analysed for potential hydrocyanic acid (HCN) yield. The quality attributes were regressed on time in order to describe accurately the quality of a forage at different times in its growth. Sorghum species, particularly the sweet sorghum hybrids and perennial sorghum, had high HCN potentials (0.15 and 0.14, respectively, at 8 weeks). They had low contents of sulfur, especially in the stem fraction and this decreased with time. Hence the nitrogen:sulfur ratio was always marginally high or, in sweet sorghum hybrids and perennial sorghum, above the recommended optimum of 15:1 for animal nutrition. Furthermore, they were deficient in sodium, particularly in the leaf fraction, while digestibility decreased rapidly with age. Nevertheless, Piper Sudangrass had a low HCN potential, which would allow it to be grazed early when digestibility was high (70% at 7 weeks). Maize had a negligible HCN potential, a nitrogen: sulfur ratio consistently below 15: 1 and a sodium content intermediate between sorghum and millet species. Millets had a negligible HCN potential and high sodium content, particularly Echinochloa utilis. This species also had a high sulfur content and hence very low nitrogen: sulfur ratio; it is recommended for early grazing to obtain high quality forage.

1985 ◽  
Vol 25 (2) ◽  
pp. 411 ◽  
Author(s):  
DK Muldoon

Sorghum bicolor x S. sudanense hybrid cv. Sudax ST6 and Echinochloa utilis cv. Shirohie were grown under irrigation at Trangie, New South Wales. Six rates of nitrogen (N) fertilizer were applied at sowing: 0, 25, 50, 120, 300, 450 kg N/ha. Height and dry matter yield were recorded at head emergence, together with the leaf hydrocyanic acid (HCN) potential, and leaf and stem dry matter digestibility, nitrogen, sulfur and sodium contents. Both the sorghum hybrid and the millet reached maximum forage yields (16.1 and 7.6 t/ha, respectively) at 350 kg N/ha. However, the tall-growing forage sorghum produced more dry matter than millet and consequently was more responsive to fertilizer nitrogen. In sorghum the leaf HCN potential increased linearly in response to N (8.5 x 10-4 %/kg N.ha). Since there was no compensating increase in the sulfur content (0.072%), and, assuming a requirement of 1.2 g S/g of HCN detoxified, sorghum lacked sufficient sulfur to detoxify the HCN potentially released in the rumen from sorghum receiving 150-200 kg N/ha. At this rate of nitrogen application, sorghum was producing only two-thirds of its forage yield potential. The sodium content of sorghum (0.013%) was not affected by nitrogen. In millet the nitrogen and sodium contents increased as applied nitrogen promoted growth. Plant sulfur was diluted initially but the nitrogen: sulfur ratio increased steadily (0.0067 units/kg N.ha). In contrast to sorghum, therefore, nitrogen fertilizer can be used to increase the dry matter yield of millet without jeopardizing forage quality and hence animal production.


1975 ◽  
Vol 15 (73) ◽  
pp. 211 ◽  
Author(s):  
TH Stobbs

Yield and nutritive value of three summer annual forages, hybrid forage sorghum (Sorghum spp. hybrid cv. Zulu), bulrush millet (Pennisetum typhoides cv. Tamworth) and white panicum millet (Echinochloa crusgalli var. edulis) were determined in three experiments. Uninterrupted growth was measured every 2 weeks between 4 and 12 weeks after sowing, and leaf, stem and inflorescence components analysed for nitrogen, phosphorus, calcium, magnesium, sodium and potassium and dry matter digestibility by an in vitro technique. The value of 10-week-old herbage, from crops grown with 50 kg ha-1 N, was determined by grazing with 18 Jersey cows and by feeding chopped material to 12 cows indoors. White panicum was the lowest yielding forage (up to 6,360 kg ha-1 at 10 weeks) but contained the highest concentration of nitrogen, phosphorus, calcium and magnesium in both leaf and stem fractions at all stages of growth. After 10 weeks growth this feed contained a high proportion of seed and was eaten in arger quantities than zulu sorghum or bulrush millet. Cows grazing white panicum produced the highestr lmilk yields (6.5 and 7.1 kg cow-1 day-1 indoors and grazed) and milk from these cows contained a highe solids-not-fat and protein content than milk from cows fed bulrush millet or sorghum. Zulu sorghum was highest yielding (1 1,240 kg ha-1 at 12 weeks in experiment 1 and 81 50 kg ha-1 at 10 weeks in experiment 2). With advancing maturity stem content increased (>80 per cent from 8 weeks onwards) and the nitrogen content of both leaf and stem fractions rapidly declined to sub-optimum levels. Milk production of cows feeding on zulu sorghum was low, averaging 4.7 and 6.0 kg cow-1 day-1 for indoor and grazing experiments. Bulrush millet produced high forage yields with a higher leaf content than zulu sorghum and milk yields were higher. Butterfat content of milk from cows feeding on bulrush millet was lower than when cows were fed the other forages. It was concluded that these three forages are capable of providing a large bulk of feed but their feeding value at a semi-mature stage of growth is similar to perennial tropical pastures.


2016 ◽  
Vol 3 ◽  
pp. 48
Author(s):  
Carlos Rodríguez ◽  
Juan A. Quiñones ◽  
Rodrigo Arias

The trial was conducted at the Centro de Producción Agrícola of ICfA in Cuyuta, Escuintla-Guatemala in order to generate information on the yield and quality of edible mulberry (Morus sp.) roughage treatments consisted of three harvest frequencies (6; 9 and 12 weeks and three fertilization levels of nitrogen (0.40 and 80 kg/ha). A complete randomized block experimental design, with a factorial arrangement (3x3) was used. The cutting height was 0.3 m above the ground level with two sequencies: from August 2nd to September 13 th and from September 13th to December 6th, 1990. In both cases, the 12 week frequency cutting and 80 kg of N were superior to the others (P<=0.01), yielding 6.87 and 6.15 t/ha of dry matter respectively. The yields at 9 weeks were statistically higher than those at 6 weeks. The highest protein percentage of the whole plant, leaves and stalks were produced at 6 weeks. The dry matter digestibility values in vitro showed little variability among treatments, with averages for whole plants, leaves and stalks of 65, 91 and 41 %, respectively. The preceeding data suggests that the mulberry has an excellent potential as a balanced supplement (protein and energy) for dual purpose cattle on the Southern coast of Guatemala.


1984 ◽  
Vol 6 (2) ◽  
pp. 86 ◽  
Author(s):  
Rees H van ◽  
JA Beard

Seasonal trends in in vitro digestibility, nitrogen, calcium, magnesium, phosphorus, potassium and sodium content were assessed for 10 alpine plant species, during the summer months of 1981182, on an alpine range in north-east Victoria, Australia. In March, 1983, at the end of an unusually dry summer the same species were tested for in vitro digestibility and nitrogen content. In vitro digestibility and nitrogen content of the alpine plant species sampled were estimated to be sufficient for lactating pregnant cattle during December and January. Towards the end of the grazing season, from late February until late March, the in vitro digestibility and nitrogen content of some of the common alpine species had declined to a point where they were too low to provide cattle with sufficient energy and protein. In general, the level of the macro-element content of the plants, as sampled, was inadequate for optimum animal production throughout the season.


1987 ◽  
Vol 35 (1) ◽  
pp. 21-28
Author(s):  
M. Warndorff ◽  
A. Dovrat ◽  
T. Kipnis

Whole plants were sampled every 10 or 11 days from field-grown P. americanum X P. purpureum canopies which were cut at intervals of 3 or 6 weeks. Tillers of varying lengths were analysed for in vitro dry matter digestibility (IVDMD). During the growing period, average whole tiller digestibility decreased, as did differences between tillers of different lengths. In 42-day-old herbage, no difference in IVDMD was found between 10 and 70 cm tillers. The decline in digestibility with time was attributed to (1) the appearance of tall tillers and (2) the detrimental effects of low light intensities on tillers growing deep in the canopy. Results suggested that it is doubtful whether tiller length or other morphological or physiological traits can be used to predict herbage digestibility, and that in breeding for better digestibility selection for stem digestibility per se should be more promising than selection for reduced stem growth. (Abstract retrieved from CAB Abstracts by CABI’s permission)


2002 ◽  
Vol 82 (2) ◽  
pp. 383-393 ◽  
Author(s):  
G. F. Tremblay ◽  
G. Bélanger ◽  
K. B. McRae ◽  
R. Michaud

Increased dry matter digestibility and ruminal undegradable protein (RUP) concentration are traits highly ranked to improve the nutritive value of forage legumes. Whole-plant, leaf, and stem samples of 27 alfalfa cultivars grown in eastern Canada were analysed for total nitrogen (TN), in vitro RUP, and in vitro dry matter digestibility (IVDMD). The objectives were to determine if significant variation exists among these cultivars, and to establish the relationship between nutritive value parameters of leaves and stems, and those of whole plants. Cultivars were seeded in triplicate on 2 consecutive years and evaluated during the 2 subsequent production years with two harvests per year. There were significant differences among cultivars in IVDMD of stems and plants in spring growth and summer regrowth. Cultivar differences in leaf IVDMD were significant only in spring growth, but this variation was negligible in practical terms. Cultivars with high forage IVDMD also had high stem IVDMD and this relationship was stronger in summer regrowth. Alfalfa plant IVDMD is a function of stem digestibility and the leaf weight ratio (LWR). Cultivar differences were significant for plant TN in spring growth and summer regrowth, and for stem TN in spring growth only. Leaf (270 to 306 g kg-1 TN) and stem (242 to 287 g kg-1 TN) RUP concentrations varied among cultivars in spring growth. Cultivars with high stem RUP also had high leaf RUP concentration but differences in plant RUP were not always attributed to leaf and stem RUP. The RUP concentration was on average 10% higher in leaves than in stems in spring growth, and this difference reached 15% in summer regrowth. The LWR varied among cultivars in spring growth and summer regrowth, and it was positively related to plant RUP in spring growth. Improved whole-plant RUP concentration is unlikely to be achieved by simply selecting for high RUP in leaves or stems; LWR has a principal role in determining alfalfa plant RUP concentration. Key words: Dry matter digestibility, ruminal undegradable proteins, alfalfa, genetic variation, stems, leaves


2012 ◽  
Vol 11 (2) ◽  
pp. 114-120 ◽  
Author(s):  
S. K. Pahuja ◽  
C. Aruna ◽  
P. K. Shrotria ◽  
Simarjit Kaur ◽  
B. R. Ranwah ◽  
...  

Improvement in multi-cut forage sorghum varieties that can perform better than SSG 59-3, a sweet Sudan grass released in 1974, has been a challenge. Efforts were made to create variability in SSG 59-3 through mutagenesis using both physical and chemical mutagens. Fifteen such mutants were evaluated for 2 years in different locations in India. Considerable variability was observed for important fodder yield and quality traits. SSG 237 flowered 10 d early than SSG 59-3. SSG 231, SSG 260, SSG 232 and SSG 237 had high protein percentage andin vitrodry matter digestibility (IVDMD) values compared with SSG 59-3. Hydrocyanic acid (HCN), a major anti-nutritional factor, was low in six mutants, the lowest being in SSG 226. This variability can be used in different breeding programmes aimed at improving multi-cut forage sorghum varieties. The lines with improved fodder quality (low HCN, high protein and IVDMD) can be used in the breeding programme for the improvement in multi-cut forage sorghum varieties.


Author(s):  
Janet H. Woodward ◽  
D. E. Akin

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1120G-1120
Author(s):  
J. L. Jacobs ◽  
C. T. Stephens

Several growth hormone combinations and silver nitrate concentrations were examined for their effect on regeneration of different pepper genotypes. Primary leaf explants from in vitro seedlings were cultured on a revised Murashige and Skoog medium supplemented with auxin, cytokinin and 1.6% glucose. Combinations of different concentrations of indole-3-acetic acid (IAA), 0-5 mg/l, and 6-benzylaminopurine (BAP), 0-5 mg/l, were tested to determine the most effective medium for shoot primordium formation. Experiments with IAA and BAP did not result in a specific growth hormone combination appropriate for regeneration of all genotypes tested. Of the silver nitrate concentrations tested, 10 mg/l resulted in the best shoot and leaf differentiation and reduced callus formation. Differences in organogenic response of individual genotypes were evaluated on a single regeneration medium. Whole plants were regenerated from 11 of 63 genotypes examined. Based on these experiments, a reproducible regeneration system for pepper was developed with a total of 500 plants regenerated to date.


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