Application of the Dumas micromethod to pasture nitrogen analysis

White, E. P.; Thompson, F.B.; Brice, N.

doi:10.1039/an9487300146

Cited by 15 publications

(9 citation statements)

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“…Boron was determined spectrographically in a perchloric-nitric acid digest of the plant material by a porous cup spark method using gallium as an internal standard. Nitrogen in the plant material was determined by the Kjeldahl method of White, Thompson, and Brice (1948).…”

Section: Methodsmentioning

confidence: 99%

Boron deficiency in white clover (Trifolium repensL.) seedlings grown in an organic soil

Sherrell¹

1966

New Zealand Journal of Agricultural Research

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1025In a pot trial using Rukuhia peat, white clover (Trifolium repells L.) seedlings grown without added boron developed distinctive deficiency symptoms. The addition of borax at 20 lb per acre increased the dry matter yield five-fold at the first harvest. This response diminished in subsequent harvests, and after three harvests there was no response in dry matter yield.BOro'l application increased the boron content of the plants at all harvests but it affected the nitrogen content of the plants in the same way as it did dry matter yield. It is concluded that the effect of boron was an indirect one and that it operated through an effect on the nitrogen nutrition of the clovers.A considerable amount of the added boron was rendered insoluble in hot water during the period of the trial.

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Section: Methodsmentioning

confidence: 99%

Boron deficiency in white clover (Trifolium repensL.) seedlings grown in an organic soil

Sherrell¹

1966

New Zealand Journal of Agricultural Research

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“…A Kjeldahl method (White, Thompson & Brice, 1948) was used for nitrogen estimation, and ash was determined by ignition in a muffle furnace for 2 h at 600 °C. Silica is given as the portion of the ash insoluble in 2N-HC1 after evaporation to dryness with 6N-HC1 (Vogel, 1961).…”

Section: Methodsmentioning

confidence: 99%

Digestibility and chemical composition of fractions of lucerne during spring and summer

1970

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Bulk harvests of primary growth were made at intervals during the spring and summer of 2 consecutive years from an ungrazed area of lucerne (Medicago sativa) and the digestibility by sheep was measured. At the same times, shoots of known length representative of the sward were collected, divided into 7-5 cm lengths, and separated into leaf and stem for the determination of ash, nitrogen, cellulose, and in vitro organic matter digestibility.Digestibility and leaf: stem ratio of the bulk harvests decreased and dry matter increased as the season advanced. Leaf composition changed little, but stem increased in lignin and decreased in ash and in vitro digestibility. In vitro digestibility and leaf: stem ratio were highly correlated with sheep digestibility.Chemical composition of shoots of known heights was similar to that of the bulk harvests. Leaf weights/shoot tended to increase linearly with height of shoot, whereas stem increased nearly as the square of the height. Dry matter of leaf and stem were inversely related to leaf:stem ratio. Stem digestibility decreased with leaf:stem ratio and with increase in shoot height.Chemical components of shoot fractions were associated with each other and were largely dependent on the distance from the top of the shoot at which they had been taken, irrespective of shoot height or time of year. Bottom stems had lower ash, nitrogen and digestibility but higher cellulose, dry weight and dry matter than top stems, whose composition approached that of leaves. Leaf fractions showed little consistent trend with position on the shoot.Some of the difficulties in studying changes in plant composition under field conditions are discussed. INTRODUCTIONreported by Mowat et al. (1965a, 6) to be similar; they suggested that digestibility might be preDespite the large niunber of chemical analyses dieted on a date basis by adjusting for particular which have been carried out on lucerne (Medicago year effects. sativa), information on the comparative nutritional The nutritive value of the material eaten by the value of various parts of the plant at different grazing animal may be greatly influenced by the times of the year is limited. Terry & Tilley (1964) height and stage of growth of the pasture and by divided lucerne stems into 6 in lengths and found the degree of selection, and cannot be determined that there was a progressive decline in digestibility merely by whole plant analysis. This paper reports from top to bottom, though the digestibilities of work carried out during two seasons, in an attempt equivalent stem fractions in young and mature to characterize more clearly plants at different stages plants were very similar. Davies (1963) observed of growth so that general predictions of the quality that as the season advanced and plant height of herbage available to the grazing animal might be increased, the leaf and upper third of the stem made. maintained high digestibilities, but formed a de-MATERIALS AND METHODS creasing portion of the total yield; the lower stem fell steeply in digest...

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“…Dry-matter determinations were made by drying to constant weight at 100 °C in a forced-draught oven. Ash was measured on dried ground samples following incineration in a muffle furnace at 600 °C for 2 h. Nitrogen was estimated on dried ground-diet samples, macerated wet faeces and urine samples by a Kjeldahl method (White, Thompson & Brice, 1948).…”

Section: Live Weightmentioning

confidence: 99%

Retention of energy and nitrogen by young sheep on different feeding patterns

1972

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In each of two experiments the comparative slaughter technique was used to compare the retention of energy by young Border Leicester x Merino wethers when the same total amount of food was offered according to two different feeding regimens. These were designed to simulate, in pens with a diet of pelleted lucerne, feeding patterns typical of continuous and intensive rotational grazing.In the first experiment ten 9-month-old sheep that were offered the same amount of food daily (mean intake 367 g digestible organic matter) during each of 14 weeks made mean daily gains of 39 g live weight, 6-3 g body fat and 0-59 MJ (140 kcal) energy compared with a gain of 30 g live weight, a loss of 1-4 g body fat and a gain of 0-28 MJ (67 kcal) energy by a similar group that ate the same total quantity of food but in amounts that ranged, during each week, from 1-8 to 0-1 times the daily intake of the other group. This cyclic feeding pattern caused a small decrease in the digestibility of dietary organic matter.In the second experiment two similar feeding patterns were compared with ten pairs of 3-month-old sheep eating twice as much food each week as in the first experiment. One member of each pair was, in each of 13 weeks, offered food ad lib. for 3 days and then amounts falling to 20 % of voluntary intake on the seventh day; the other one ate the same amount of food each week but in seven almost equal feeds. The latter sheep gained, on average, 132 g live weight daily and retained 58 g body fat and 2-96 MJ (707 kcal) energy compared with 124 g live weight, 49 g body fat and 2-61 MJ (624 kcal) energy by the sheep on the cyclic feeding pattern. In neither experiment was wool growth affected by feeding pattern.The greater effect of the cyclic feeding pattern in reducing the efficiency of energy retention in the first experiment is attributed to the higher number of days each week during which these animals were estimated to be in negative energy balance. These results suggest that adverse nutritional effects of a fluctuating feeding pattern in rotational grazing are likely to be most important where sheep are being rationed near their maintenance level and only small where food is ample. Graham (1967) showed that adult sheep were less efficient when fed every fourth day than when fed Most of the experiments comparing continuous daily. and rotational systems of grazing management (seeThe two experiments described in this paper were Wheeler, 1960) have been designed to test the designed to compare, by means of the comparative possibility that intermittent grazing affects animal slaughter technique, the effect of two different production by changing the growth rate of herbage, feeding patterns, one simulating continuous grazing However, rotational grazing also imposes on the and the other rotational grazing, on the retention animal a cyclic pattern of food consumption that of energy by penned sheep. Young sheep were used follows the decreasing availability of herbage to give a more sensitive test of the feeding treatduring the grazi...

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Application of the Dumas micromethod to pasture nitrogen analysis

Cited by 15 publications

References 0 publications

Boron deficiency in white clover (Trifolium repensL.) seedlings grown in an organic soil

Boron deficiency in white clover (Trifolium repensL.) seedlings grown in an organic soil

Digestibility and chemical composition of fractions of lucerne during spring and summer

Retention of energy and nitrogen by young sheep on different feeding patterns

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