Sulphur metabolism in sheep. IV. The effect of a varied dietary sulphur content on some body fluid sulphate levels and on the utilization of urea-supplemented roughage by sheep

1969 ◽  
Vol 20 (4) ◽  
pp. 759 ◽  
Author(s):  
AC Bray ◽  
JA Hemsley

A diet composed of oaten hulls, urea, and mineral mixture was shown to be deficient in sulphur with respect to the nutrition of sheep. Sulphate supplements to the diet increased both crude fibre digestion and nitrogen and sulphur retention. They also increased the concentration of inorganic sulphate in the blood and the levels of total sulphur and total sulphate sulphur in the parotid saliva, but decreased blood urea nitrogen levels and the concentration of residual nitrogen and residual sulphur (protein fraction) in the parotid saliva. The effect of these concentration changes is discussed with particular reference to the feeding of sheep on low sulphur, low nitrogen forages.

1972 ◽  
Vol 25 (6) ◽  
pp. 1377 ◽  
Author(s):  
RFH Dekker ◽  
GN Richards

The dry matter digestibility (DMD) of poor quality roughages such as spear grass (Heteropogon contortus) by sheep and cattle has been shown to increase on addition of sulphur to the diet. The sulphur is added most frequently as inorganic sulphate, either alone (Playne 1969) or supplemented with urea (Bray and Hemsley 1969; Kennedy and Siebert 1972; Siebert and Kennedy 1972) or gluten (Playne 1969). These supplements have also increased feed intake in sheep (Playne 1969; Kennedy and Siebert 1972; Siebert and Kennedy 1972) and cattle (Siebert and Kennedy 1972), and have improved the nitrogen and sulphur balance (Moir, Somers, and Bray 1967; Bray and Hemsley 1969; Playne 1969; Kennedy and Siebert 1972) within the animal. Sulphates have been shown to increase the in vitro rumen digestion of starch (Kennedy, Mitchell, and Little 1971), crude fibre (Bray and Hemsley 1969), and acid-detergent fibre and cellulose (Barton, Bull, and Hemken 1971).


1940 ◽  
Vol 18c (4) ◽  
pp. 136-141 ◽  
Author(s):  
R. Newton ◽  
R. S. Young

Proximate analyses of roots (to plow depth) and stubble in one-, three-, and five-year-old sods, considered in relation to sequence effects as judged by the nitrogen absorption of the first two wheat crops after each age of sod, indicated the nitrogen content of the hay crop residues to be the dominant influence. Alfalfa was much superior to the grasses, a result apparently of the higher quantity of nitrogen returned to the soil and of the narrower C:N ratio in its residues. Timothy led the grasses, contributing the highest quantity of nitrogen in residues with the lowest percentage of crude fibre and the narrowest ratio of crude fibre to nitrogen-free extract. Brome contributed more residual nitrogen than western rye, but was slightly inferior in sequence effects.


1979 ◽  
Vol 93 (3) ◽  
pp. 657-667 ◽  
Author(s):  
J. Valentine ◽  
A. H. Charles

SUMMARYThe associations between yield, nitrogen and soluble-carbohydrate concentration within S. 23 perennial ryegrass were investigated at three levels of nitrogen application. Controlled growth room conditions were used.The simple correlation between yield and nitrogen concentration was negative at the low rate of nitrogen application, not present at the intermediate rate of nitrogen and positive though not significant at the high rate of nitrogen. Yield and soluble-carbohydrate concentration were only correlated (positively) at the low nitrogen rate.At low nitrogen there were ‘efficient’ genotypes with relatively high yield and low nitrogen concentration. ‘Inefficient’ genotypes had relatively low yields and high nitrogen concentration. The majority of genotypes were neither markedly efficient or inefficient. The efficient genotypes at low nitrogen maintained their yield advantage at higher nitrogen levels with average nitrogen concentration and high numbers of tillers. Inefficient genotypes remained relatively stable in yield, numbers of tillers and nitrogen concentration.Partial correlation indicated an underlying high degree of dependence between yield, nitrogen and soluble-carbohydrate concentration at all nitrogen levels. The association of yield and nitrogen concentration showed a similar trend over nitrogen levels to that obtained using simple correlation. Yield and soluble-carbohydrate concentration were positively related, and nitrogen and soluble-carbohydrate concentration inversely related, when the effects of the remaining attribute were eliminated.Data extracted from Lee et al. (1977) confirmed that yield and nitrogen concentration for varieties under field conditions varied with level of nitrogen application in a similar manner to genotypes in the controlled growth room. The variety (Melle) could be characterized as being particularly efficient.Both sets of results indicate that selection for high yield of nitrogen in herbage can best be achieved through selection for yield alone.


1958 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
LF Myers ◽  
J Lipsett

The effect of skeleton weed competition on the yield of wheat and oats was investigated in seasons when rainfall was plentiful. Nitrogen was found to be the major factor limiting crop yields. In soils with comparable nitrogen-supplying powers, skeleton weed density governed the crop's response to applied nitrogen. Competition between skeleton weed and crop was severe at low nitrogen levels, but minor at the high nitrogen levels achieved either by nitrogen application, or when the crop followed a legume-rich pasture. Competition had its effect early in the crop's growth. Temporary removal of competition, by spraying with plant growth regulating substances (JICPA) at different times, was used to determine when competition was critical, and measure its effects. Skeleton weed reduced nitrogen supply early in the crop's growth, and so depressed yield. An application of 1 lb MCPA per acre in the fallow 54 days before sowing, or 10 days after crop emergence, increased the yield of oats from 710 to 1350 lb grain per acre: a response equal to that from 32 lb nitrogen per acre applied at planting in the same experiment. In each case, the response to spraying at the different times was analogous to the effect of a nitrogen application at these times. Early spraying gave responses in yield; later spraying gave responses in grain nitrogen. The results provide a new estimate of the reduction in crop yield due to skeleton weed.


Botany ◽  
2011 ◽  
Vol 89 (4) ◽  
pp. 255-261 ◽  
Author(s):  
Corinthe Zekveld ◽  
John Markham

Plants can respond to herbivore damage by mounting a resistance response or by compensating for lost fitness. Both plant nutrition and interactions with soil microbes can affect these responses. It has been shown that resistance responses can occur before plants have been attacked by herbivores. Here we show that a tolerance type of response can occur when plants are exposed to, but not fed on by, herbivores. Alnus viridis (Chaix) DC. spp. crispa (Ait.) Turrill were grown in sealed containers under positive air pressure with either 0.5 mmol·L–1 or 2.0 mmol·L–1 nitrate and either inoculated or not inoculated with Frankia , their nitrogen-fixing symbiont. Plants were then exposed to the genus-specific aphid Prociphilus tessallatus Fitch, which failed to establish feeding colonies. Exposure to aphids, formation of nitrogen-fixing nodules, and elevated soil nitrogen levels all significantly increased plant yield with no interaction among these factors. A combination of high soil nitrogen, nodulation, and exposure to aphids resulted in the lowest plant root:shoot ratio. Plants that were grown with low nitrogen and were exposed to aphids showed increased nitrogen-fixing activity within a day of being exposed. These results provide further evidence to support the observation that plants can respond to cues from other organisms prior to receiving herbivore damage.


1969 ◽  
Vol 9 (37) ◽  
pp. 181 ◽  
Author(s):  
RJ Jones ◽  
Davies J Griffiths ◽  
RB Waite

Eleven introduced tropical grasses were compared in single grass swards and nine of these were compared in mixtures containing two or three grasses. The pastures received 300 lb nitrogen an acre a year as urea and were grazed five times a year. A basal legume mixture of tropical legumes and white clover sown with the grasses failed to persist. There were large differences between the grasses in competitive ability and this varied with time. Samford Rhodes grass, Nandi setaria, and Pangola were the most aggressive, and the Paspalum species-P. plicatulum P. dilatum and P. commersonii the least aggressive. Hyparrhenia hirta, which had done well at low nitrogen levels, failed to compete with weed grasses at the higher nitrogen level used in this study. Rhyncheytrum repens and commercial Rhodes grass were the dominant weed grasses in the establishment year. These rapidly decreased with time, and Digitaria didacola-blue couch, became the dominant weed species. Plots containing Nandi setaria, Samford Rhodes grass, or Pangola, gave the highest yields, and plots containing P. dilatatum the lowest. There was no yield advantage in combining grasses in mixtures-the mixture giving similar or lower yields than the best grass in the mixture grown alone. Under a period of farm grazing the three Rhodes grasses used declined sharply and the proportion of blue couch increased. The high yields from plots dominated by blue couch indicate that, agronomically, this has been a neglected naturalized species. Only Nandi setaria and Pangola were able to compete effectively with blue couch under the 'farm grazing' management imposed.


2018 ◽  
Vol 67 ◽  
pp. 35-45 ◽  
Author(s):  
Rihana Funsho Asafa ◽  
Wasiu Babatunde Akanbi

The experiments were conducted at the Teaching and Research Farm, Ladoke Akintola University of Technology, Ogbomoso, Nigeria in 2010 and 2011 to determine the effect of propagule size and nitrogen levels on the growth and rhizome yield of ginger.The nitrogen source was from Tithonia compost (TC). Three propagule sizes were tested (20, 30 and 40 g) and seven nitrogen levels (0, 40, 60, 80, 100, 120 and 140g kg N/ha). The experimental pots were laid out in a randomized complete block design with three replicates. Data were collected on growth parameters (plant height, number of leaves, leaf length and leaf width); rhizome yield components (number of tillers and rhizomes, and rhizome weight and length); and proximate composition (crude protein (CP), crude fibre (CF), total lipid (TL); Total Ash (TA), Starch and water soluble extract). Data collected were subjected to analysis of variance and significant means were compared using Duncan Multiple Range Test (DMRT) (P ≤ 0.05). Propagule size, N levels and their interactions significantly (P≤ 0.05) influenced most of the parameters assessed. In most cases, the use of 30 and 40 g planting material gave similar results. Plants nourished with 140 kg N/ha significantly and consistently outperformed others fertilized with other nitrogen levels. Crude protein obtained from 40 g propagule size was significantly ( P ≤ 0.05) higher than other tested propagule sizes. The rhizome yields of fertilized plants were significantly higher than the non fertilized plants. Rhizome yields ranged from 1.57 t/ha in none fertilized plants to 3.71 t/ha in 140 kg N/ha. In conclusion, establishment of ginger with 40 g planting materials and its nourishment with 140 kg N/ha enhanced its growth, rhizome yield and proximate compositions of the plant.


1970 ◽  
Vol 48 (6) ◽  
pp. 1437-1442 ◽  
Author(s):  
David R. Klein ◽  
Fritz Schønheyder

Among black-tailed deer (Odocoileus hemionus sitkensis), roe deer (Capreolus capreolus), and reindeer (Rangifer tarandus), nitrogen levels in the contents of the rumen show consistent patterns of variation. Among deer of each species on the same range during the same season, the animal-derived nitrogen component of the rumen contents decreases as the vegetative nitrogen component increases. This inverse relationship may result from one, or more likely both, of the following causes. (1) The ability of the ruminant to maintain a fairly constant rumen environment to allow for its most efficient function. (2) An adaptability in these deer species to compensate for low nitrogen levels in the forage by recycling of nitrogen through the saliva and further conservation of ruminal nitrogen by recycling it through successive generations of microbial populations. The apparent ability to compensate for variations in forage nitrogen levels is limited when deer are on range of general poor quality or during fall and winter when forage nitrogen levels are reduced.


1967 ◽  
Vol 18 (1) ◽  
pp. 137 ◽  
Author(s):  
N McCGraham

Energy and nitrogen balance experiments with three subtropical forages, a legume and two grasses, are reported. Each forage was given to four sheep at several levels of feeding. One of the forages had a low nitrogen content (4% crude protein) and was supplemented with urea and molasses containing 7 g nitrogen and 56 kcal/day. This caused voluntary consumption to increase by 50% and digestibility of all chemical constituents to increase by 6–12 units. Utilization of metabolizable energy for maintenance also improved by approximately 10%. Digestible energy (42–62%) was predicted quite accurately from chemical composition by means of published equations which refer to forages grown in temperate climates. Metabolizable energy was close to 82% of digestible energy, as found with non-tropical forages. Net availability of metabolizable energy for maintenance ranged from a very low 60% to 80%. It was predicted more accurately from percentage metabolizable energy than from digestible crude fibre: the reverse applied to net availability for production (40–50%).


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