The cultivation of Chondrus crispus. Factors affecting growth under greenhouse conditions

1977 ◽  
Vol 55 (16) ◽  
pp. 2263-2271 ◽  
Author(s):  
A. C. Neish ◽  
P. F. Shacklock ◽  
C. H. Fox ◽  
F. J. Simpson
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Continuous Illumination ◽  
Chondrus Crispus ◽  
Optimum Conditions ◽  
High Nitrogen ◽  
Good Source ◽  
Factors Affecting ◽  
Rapid Growth Rate ◽  
The Mean

Two methods of growing Chondrus crispus in flowing seawater in tanks in a greenhouse were used in determining some of the conditions required for the cultivation of C. crispus. In one system, individual plants were tethered to a fixed support, and in the other, the plants were allowed to float freely in circulating seawater. The addition of nitrate or ammonia and phosphate increased the growth rate, whereas iron did not. Urea was not a good source of nitrogen. Well nourished plants had a relatively high nitrogen and water content and were richly pigmented. Such plants, when grown in nutrient-deficient seawater, gradually bleached and the percentage of dry matter and carrageenan increased. Growth under conditions of continuous illumination was superior to normal illumination with alternating day and night periods. Seasonal variation in growth rates was closely correlated with the mean ambient temperature of the seawater. Epiphytes were a serious problem but became less so as optimum conditions for growth of C. crispus were approached. A single plant (T4), observed to have a relatively rapid growth rate, was selected and a clone was established by vegetative propagation.

Patterns of metamorphic age and length in marine fishes, from individuals to taxa

2000 ◽  
Vol 57 (4) ◽  
pp. 856-869 ◽  
Author(s):  
Hugues P Benoît ◽  
Pierre Pepin ◽  
Joseph A Brown
Keyword(s):  
Growth Rate ◽  
Population Level ◽  
Individual Variability ◽  
Marine Fishes ◽  
Exponential Relationship ◽  
Factors Affecting ◽  
The Mean ◽  
Time Required ◽  
Increasing Temperature ◽  
Dominant Influence

We present a summary of variability in age and length at metamorphosis for marine fishes. Data from the literature were partitioned into taxonomic, population, and individual levels of resolution to examine the factors affecting the timing of metamorphosis. Temperature appears to be a dominant influence on timing, likely due to its effect on growth rate. Interspecifically, length at metamorphosis correlated poorly with that at hatching but was significantly related to temperature. This pattern was inconsistent for population-level comparisons. Metamorphic age decreased exponentially with increasing temperature in interspecific and population-level comparisons but did not covary with length for either level of resolution. This suggests that age at metamorphosis largely reflects the time required to grow to a given metamorphic length. Within populations, the correlation between metamorphic age and length increases with growth rate, a reflection of variance in age and length. A strong exponential relationship between mean metamorphic age and length and their associated variability (SD) exists, with a slope greater than unity in both cases (i.e., variability increases relative to the mean). With these relationships, we can infer the manner in which individual variability in metamorphic traits is generated throughout ontogeny. These results are considered in light of recruitment variability in marine fishes.

scholarly journals Factors affecting growth and yield of short-duration pigeonpea and its potential for multiple harvests

1987 ◽  
Vol 109 (3) ◽  
pp. 519-529 ◽  
Author(s):  
Y. S. Chauhan ◽  
N. Venkataratnam ◽  
A. R. Sheldrake
Keyword(s):  
Short Duration ◽  
Dry Matter ◽  
Total Yield ◽  
Sowing Date ◽  
Growth And Yield ◽  
First Flush ◽  
Factors Affecting ◽  
Northern India ◽  
The Mean ◽  
Seed Yields

SummaryEnvironmental and cultural factors that may limit the yield of short-duration pigeonpea were investigated over three seasons. Plants in the peninsular Indian environment at Patancheru grew less and produced less dry matter by first-flush maturity than at Hisar, a location in northern India where the environment is considered favourable for the growth of short-duration pigeonpea. However, with a similar sowing date in June, the mean seed yields of three genotypes, ICPL 4, ICPL 81 and ICPL 87, were very similar, at about 2·3 t/ha, in both environments. This was mainly due to the higher ratio of grain to above-ground dry matter at Patancheru. In addition to the first harvest, all genotypes showed a potential for two more harvests owing to the warm winters at Patancheru. The potential for multiple harvests was particularly high in ICPL 87, which yielded 5·2 t/ha from three harvests in 1982–3, 3·6 t/ha from two harvests in 1983–4, and 4·l t/ha from three harvests in 1984–5. The optimum plant population density at Patancheru was 25–35 plants/m2 for ICPL 87, but was higher for the other two genotypes.At Patancheru, the total dry-matter and seed yield of first and subsequent harvests were significantly reduced by delaying sowing beyond June. Generally, the second- and the third-harvest yields were lower on vertisol than on alfisol under both irrigated and unirrigated conditions.The total yield of ICPL 87 from two harvests was far higher than that of a well-adapted medium-duration genotype BDN 1, grown over a similar period. The yield advantage was greater on the alfisol because of the better multiple harvest potential of this soil. The results of this study demonstrate that properly managed short-duration genotypes of pigeonpea may have considerable potential for increased yield from multiple harvests in environments where winters are warm enough to permit continued growth.

Effects of close cutting and nitrogen fertilizer on growth of a Siratro (Phaseolus atropurpureus) pasture at Samford, south-eastern Queensland

1967 ◽  
Vol 7 (25) ◽  
pp. 157 ◽  
Author(s):  
RJ Jones
Keyword(s):  
Growth Rate ◽  
White Clover ◽  
Low Temperatures ◽  
Dry Matter ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Cutting Frequency ◽  
Cutting Interval ◽  
The Mean ◽  
Tropical Grass

Uninterrupted growth of Siratro (Phaseolus atropurpureus) in a Siratro-grass pasture was slow in spring, increased rapidly in mid-December, and attained a maximum growth rate of 79 lb dry matter an acre a day in February-March. The slow spring growth appeared to be associated with low temperatures. Yield and percentage of Siratro increased for at least 191 days after commencement of growth in spring. Yields of Siratro increased linearly from 1400 lb to 6500 lb dry matter an acre as the cutting interval increased from 4 to 16 weeks. Yields of other species declined as the cutting interval increased. With a 4-weekly cutting regime, the stand of Siratro was greatly reduced after one season. Lucerne subjected to the same treatment gave higher yields and the stand remained good. Urea reduced the mean yield of Siratro by 16 per cent and 33 per cent at the N,, and N,,, levels respectively, but increased total dry matter yields. The response of Siratro to cutting frequency was quite different from that reported for white clover. This difference may be of fundamental importance in the management of sub-tropical grass-legume pastures.

The nutritional value of four tropical grasses when fed as chaff and pellets to sheep

1968 ◽  
Vol 8 (32) ◽  
pp. 270 ◽  
Author(s):  
DJ Minson ◽  
R Milford
Keyword(s):  
Nitrogen Content ◽  
Dry Matter ◽  
Physical Structure ◽  
Tropical Grasses ◽  
Factors Affecting ◽  
Digitaria Decumbens ◽  
Acid Detergent Fibre ◽  
The Mean ◽  
Voluntary Intake ◽  
Nitrogen Contents

Pangola (Digitaria decumbens), kikuyu (Pennisetum clandestinum), setaria (Setaria sphacelata), and buffel grasses (Cenchrus ciliaris) were cut at different stages of growth and artificially dried to provide ten feeds with a range of leaf percentages (13-56), nitrogen contents (0.42-3.70 per cent), and acid detergent fibre percentage (26.3-43.3). Half of each cut was chaffed and the remainder pelleted. Both pellets and chaff were fed to Merino wethers in metabolism cages. Pelleting decreased the mean digestibility of dry matter by 6.8 percentage units, nitrogen by 2.2 percentage units, and ADF by 11.5 percentage units. Pelleting increased the mean voluntary intake by sheep 47 per cent for dry matter and 27 per cent for digestible dry matter with only minor differences in response to pelleting mature and young grass. The smallest increase from pelleting was 4.1 per cent for buffel grass containing 0.42 per cent N. In grass of the same age in which the nitrogen content had been increased to 0.75 by fertilizer nitrogen, pelleting increased intake by 26.6 per cent. It was concluded that with mature tropical grasses the response to pelleting may be limited by a low nitrogen content. Pelleting may be a useful technique for eliminating the effect of physical structure when studying factors affecting the voluntary intake of pasture plants.

A note on the effect of variety, type of straw and ammonia treatment on digestibility and on growth rate in steers

1988 ◽  
Vol 47 (1) ◽  
pp. 157-160 ◽  
Author(s):  
G. W. Reid ◽  
E. R. Ørksov ◽  
M. Kay
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Spring Barley ◽  
Live Weight ◽  
Ammonia Treatment ◽  
Golden Promise ◽  
Predicting Performance ◽  
Chemical Measurements ◽  
The Mean ◽  
Voluntary Intake

Forty Hereford cross steers of 350 kg live weight were allocated to 10 treatments in which straw was offered ad libitum. The straws comprised two varieties of winter barley (Gerbel (G) an Igri (I)), two varieties of spring barley (Corgi (C) and Golden Promise (GP)) and one variety of winter wheat (Norman (N)). Each straw was offered either untreated (with 20 g urea per kg added at feeding), or treated (with 30 g anhydrous ammonia). After 10 weeks the treatments were changed. The mean growth rates for steers receiving the untreated straws were 0·11, 0·13, 0·40, 0·20 and 0·27 kg/day and for treated straws were 0·36, 0·33, 0·61, 0·60 and 0·52 kg/day for G, I, C, GP and N respectively. The straw intakes for untreated straws were 3·4, 3·6, 5·2, 4·4 and 4·6 kg dry matter per day and for treated straws 4·7, 4·8, 5·9, 4·9 and 5·8 kg dry matter per day for G, I, C, GP and N respectively. Chemical and biological measurements were compared as predictors of voluntary intake of straw and growth rate in the steers. Biological measurements were very efficient in predicting performance of the steers while chemical measurements were much less valuable.

Straw degradability as a predictor of intake and growth rate in sheep

1998 ◽  
Vol 67 (3) ◽  
pp. 485-490 ◽  
Author(s):  
S. Yalçin ◽  
A. Şehu ◽  
A. G. Önol
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Correlation Coefficients ◽  
Exponential Model ◽  
Apparent Digestibility ◽  
Rumen Degradation ◽  
Acid Detergent Fibre ◽  
The Mean ◽  
Ad Libitum ◽  
Male Sheep

AbstractThe dry-matter (DM) intake and growth rate in male lambs were predicted from rumen degradability characteristics, rumen DM losses at different times, neutral- or acid-detergent fibre (NDF or ADF) contents and DM apparent digestibility of roughages. Four different straws consisting of wheat, barley, oat and rice were each offered ad libitum to 24 Merino male lambs with 200 glday concentrate for 4 weeks to determine DM intake and growth rate. Apparent digestibilities of the straws were measured with three Merino male sheep. Measurements were made during the last 10 days of each 20-day period. The degradation characteristics of the straws were measured by incubating samples in nylon bags for 8, 16, 24, 48, 72 and 96 h in the rumens of three Merino male sheep fitted with rumen cannulae. The exponential model p = a + b(l - er^) was fitted to the data. Potential degradabilities of DM (defined as a + b) and apparent digestibilities of DM ranged from 530 to 679 and 440 to 560 g/kg, respectively. The mean DM intake of the straws varied from 543 to 745 glday, the digestible DM intake from 236 to 417 glday and growth rate from 17 to 95 glday. Using the degradation characteristics A, B and c in a multiple regression analysis, the correlation coefficients with DM intake and growth rate were 0·79 and 0·70, respectively. NDF and ADF were related to DM intake (i = 0·65; r = 0·64) and growth rate (r = 0·55; r = 0·56). The correlation coefficient between DM apparent digestibility and DM intake was 0·76. It is concluded that the rumen degradation characteristics have potential for predicting intake of straws and growth rate in sheep.

scholarly journals Factors Affecting Birth Weight And Growth Rate In Friesian X Bunaji Calves

2021 ◽  
Vol 19 ◽  
pp. 101-106
Author(s):  
O. W. Ehoche ◽  
A. E. O. Malau-aduli ◽  
B. Y. Abubakar
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Birth Weight ◽  
Significant Influence ◽  
Season Of Birth ◽  
Correction Factors ◽  
Wet Season ◽  
Factors Affecting ◽  
Body Weights ◽  
The Mean

Calving records from 1984 - 1989 were studied to determine the influence of rearing method, sex of calf, season of birth, dam breed and year of birth on body weight at birth, 3,6 and 12 months of age in Friesian x Bunaji calves. The mean weights of calves at birth, 3, 6 and 12 months of age were 22.0, 68.2, 96.7 and 137.4 kg, respectively. Sex of calf had a significant effect, with male calves being heavier than the females by 1.2, 5.9 and 9.7 kg at birth, 3 and 6 months of age respectively. The effect of season of birth on calf body weights was not significant except at 6 months of age, when calves born during the wet season were heavier (P<0.01) than those born in the harmattan period by 9.5 kg. Year of birth had a highly significant effect (P<0.01) on calf weights from birth to yearling. Method of rearing and dam breed had no significant influence on all the weights. The results suggest the need to develop correction factors for standardisation of weight records when comparing dams on the basis of body weights of their calves.

Response to supplementary sorghum grain by cattle grazing oats

1976 ◽  
Vol 16 (82) ◽  
pp. 646 ◽  
Author(s):  
B Gulbransen
Keyword(s):  
Growth Rate ◽  
Avena Sativa ◽  
Dry Matter ◽  
Cattle Grazing ◽  
Animal Performance ◽  
The Mean ◽  
Ad Libitum ◽  
Sorghum Grain ◽  
Feeding Systems

Seven groups each of five 18-month-old steers grazed oats (Avena sativa) at allowances ranging from 0.40 to 0.08 ha head-l. A further group in a concrete yard was fed ad libitum a diet consisting solely of sorghum grain. Six of the grazing groups were supplemented with ad libitum sorghum grain. The steers were slaughtered after an average of 100 days on trial. The mean daily grain dry matter consumption of grazing steers ranged from 2.90 to 6.52 kg head-1. Carcase gain ha-1 was linearly related to grain consumption ha-l and increased by 0.097 kg for each kg of grain dry matter consumed. Fasted liveweight gain and growth rate were shown to be unsatisfactory measures of animal performance in pasture/grain feeding systems.

THE RATE OF DRY WEIGHT ACCUMULATION IN MARQUIS WHEAT AS AFFECTED BY TEMPERATURE AND LIGHT INTENSITY

1962 ◽  
Vol 40 (7) ◽  
pp. 939-955 ◽  
Author(s):  
D. J. C. Friend ◽  
V. A. Helson ◽  
J. E. Fisher
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Relative Growth Rate ◽  
Growth Period ◽  
Dry Weight ◽  
Continuous Illumination ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
The Mean

Plants were grown to the stage of anthesis at constant temperatures from 10 to 30 °C and under continuous illumination at intensities ranging from 200 to 2500 ft-c. The absolute growth rate was maximal at the time of ear emergence. The relative growth rate declined continuously with time; the rate of decline was greatest at the higher temperatures and light intensities. The optimal temperature for the mean absolute growth rate over the whole growth period was 20–25 °C. The optimum for the mean relative growth rate was 15–20 °C. This difference is attributed to the faster rate of floral development at high temperatures. Both absolute and relative growth rates increased with increasing light intensity up to 2500 ft-c.

scholarly journals Factors affecting the voluntary intake of food by cows

1966 ◽  
Vol 20 (2) ◽  
pp. 229-244 ◽  
Author(s):  
R. C. Campling ◽  
M. Freer
Keyword(s):  
Dry Matter ◽  
Alimentary Tract ◽  
Crude Fibre ◽  
Factors Affecting ◽  
The Poor ◽  
Food Digestibility ◽  
Oat Straw ◽  
The Mean ◽  
Voluntary Intake ◽  
The Relationship

1. Two experiments were conducted to examine the effect of grinding and pelleting roughages on the voluntary intake of food, digestibility, time of retention of food in the digestive tract, amounts of digesta in the recitulo-rumen and eating and ruminating behaviour of adult, non-lactating, non-pregnant cows. The first experiment was with artificially dried grass and the second with oat straw; also, with a diet of ground, pelleted oat straw the effect was studied of giving a daily intraruminal infusion of 150 g urea. The size of the particles of the ground roughages are given. 2. The mean voluntary intakes of long and ground dried grass were similar, the voluntary intake of ground, pelleted oat straw was 26% greater than that of long straw and the daily infusion of urea increased the voluntary intake of ground, pelleted oat straw by 53%. 3. The digestibility of the ground roughages was lower than that of the long roughages, the lower digestibility of the ground roughages was due mainly to the poor digestibility of crude fibre in the reticulo-rumen. The rate of disappearance of cotton thread placed in the ventral sac of the rumen was slower with ground than with long roughages. 4. The mean times of retention of ground roughages were shorter than those of long roughages when equal and restricted amounts of each food were given; with food offered ad lib. there was little difference between the mean times of retention of long and ground roughages in the alimentary tract. 5. On average, the mean amounts of digesta dry matter in the reticulo-rumen immediately after a meal were about the same with long and ground dried grass, with long and ground oat straw the amounts of dry matter were similar, but when the intraruminal infusion of urea was given the amount of dry matter increased by 49%. 6. The rate of eating (min/kg food) ground, pelleted roughages was much faster than that with long roughages; when the cows received ground roughage rumination did not occur but during short periods triple reticular contractions were seen. 7. The relationship between the voluntary intake of food, the amount of digesta in the reticulo-rumen and the rate of disappearance of digesta from the alimentary tract is discussed.

Sign in / Sign up

Export Citation Format

Share Document