Effects of Salinity on the Survival and Growth of Pre-Smolt Coho Salmon (Oncorhynchus kisutch)

1971 ◽  
Vol 28 (3) ◽  
pp. 343-349 ◽  
Author(s):  
Robert G. Otto
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Conversion Efficiency ◽  
Salinity Tolerance ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Management Tool ◽  
Food Conversion ◽  
Survival And Growth ◽  
Food Conversion Efficiency

Salinity tolerance of juvenile coho salmon (Oncorhynchus kisutch) increased markedly during the period from approximately [Formula: see text] months after emergence from the gravel to the onset of the smolt transformation, except for a decline in the fall. In January, salinity tolerance ceased to limit dispersal to the sea. The limiting effects of high salinities on survival were less for larger fish than for smaller individuals and were substantially reduced by a period of exposure to dilute salinities. Growth rate, food intake, and gross food conversion efficiency had the highest values at salinities of 5–10 ppt throughout the pre-smolt period. The results are discussed in relation to the feasibility of using saltwater impoundments as a management tool in increasing coho production.

Influence of shearing and level of concentrates offered on the performance of lambs

1990 ◽  
Vol 1990 ◽  
pp. 164-164
Author(s):  
H.J. Black ◽  
D.M.B. Chestnutt
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Conversion Efficiency ◽  
Food Conversion ◽  
Ad Libitum ◽  
Food Conversion Efficiency ◽  
Voluntary Food Intake

It has been clearly established that shearing ewes during pregnancy increases lamb birthweight (Austin and Young, 1971; Rutter, Laird and Broadbent, 1971; Black and Chestnutt, 1990). Fewer studies have examined the response of fattening lambs to shearing although both Salman and Owen (1981) and Marai, Nowar and Bahgat (1987) noted a significant increase in growth rate. This was accompanied by an increase in voluntary food intake and consequently little change in the food conversion efficiency.The objective of these experiments was to study the influence of shearing on voluntary food intake and growth rate of fattening lambs offered various levels of concentrate feeding plus ad libitum forage.

Age- and sex-dependent stimulation of growth rate in rats by the adrenal inhibitor trilostane

1987 ◽  
Vol 113 (3) ◽  
pp. 479-484 ◽  
Author(s):  
M. N. Sillence ◽  
R. G. Rodway
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Conversion Efficiency ◽  
Plasma Corticosterone ◽  
Female Rats ◽  
Male Rats ◽  
Dependent Manner ◽  
Food Conversion ◽  
Male And Female Rats ◽  
Food Conversion Efficiency

ABSTRACT The effects of the adrenal inhibitor trilostane were examined in male and female rats to determine whether growth rate could be improved by lowering circulating plasma corticosterone concentrations. Dose–response studies revealed that in young female rats (125 g) trilostane lowered peak plasma corticosterone levels in a dose-dependent manner. In male rats plasma corticosterone concentrations were reduced only by very high doses of trilostane (200 mg/kg), while lower doses (2–8 mg/kg) actually increased them. Five growth studies were conducted using a total of 90 rats. In female animals, daily injections of trilostane (10 mg/day) caused an age-dependent increase in growth rate ranging from 11% in 127 g rats to 30% in 164 g rats. In three out of four experiments using females, food intake was slightly increased by the drug. Food conversion efficiency was improved consistently by trilostane by up to 18%. Trilostane-treated females had significantly heavier adrenal glands and livers, but lighter kidneys than control rats. When a complete carcass analysis was performed on one experimental group, no significant differences were found. Carcass component weights relative to control values were: body weight (103%), body water (105%), fat-free solids (103%), carcass weight (103%), body length (103%), body fat (95%) and gut content (96%). In male rats (160 g), daily injections of trilostane (10 mg) resulted in a steady and sustained depression of growth rate reflecting a similar fall in food intake, with no change in food conversion efficiency. It is concluded that in older female rats growth rate is constrained by physiological concentrations of glucocorticoids. Younger females are either less sensitive to trilostane or to changes in plasma corticosterone levels. Male rats are less responsive to adrenal suppression by trilostane than are females of a similar age and do not exhibit an anabolic response to this drug. J. Endocr. (1987) 113, 479–484

Multibreed comparisons of British cattle. Variation in relative growth rate, relative food intake and food conversion efficiency

1985 ◽  
Vol 41 (2) ◽  
pp. 193-199 ◽  
Author(s):  
R. B. Thiessen ◽  
C. S. Taylor ◽  
J. Murray
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Genetic Variation ◽  
Food Intake ◽  
Relative Growth Rate ◽  
Conversion Efficiency ◽  
Food Conversion ◽  
Relative Growth ◽  
Breed Selection ◽  
Food Conversion Efficiency

ABSTRACTIn a multibreed experiment in which 292 heifers from 25 breeds were given a single complete pelleted diet ad libitum, body weight and food intake were recorded every 2 weeks. Relative growth rate, relative food intake and food conversion efficiency were calculated as the ratio of weight gain to body weight, food intake to body weight and weight gain to food intake respectively. The traits were measured over 12-week intervals from 12 to 72 weeks of age, and also over longer intervals of 24, 36, 48 and 60 weeks, each beginning at 12 weeks of age. Relative growth rate and food conversion efficiency declined continuously with increasing age, whereas relative food intake increased to a maximum in the 24- to 36-week period and then declined continuously.The between-breed genetic coefficient of variation (CVb) for relative food intake was very stable at about 0·04 whether measured over 12-week or longer intervals, whereas the CVVs for relative growth rate and food conversion efficiency were usually higher when measured over 12-week intervals compared with longer intervals. For the entire period from 12 to 72 weeks, the CVb was estimated as 0·029 for relative growth rate, 0·040 for relative food intake and 0·034 for food conversion efficiency. The corresponding intraclass correlations (t2) measuring the between-breed variation as a proportion of the total variation were estimated as 0·08, 0·18 and 0·15. Within-breed variation was thus much greater than between-breed variation for all three traits. Using published estimates of within-breed heritabilities, the parameters g21 measuring the between-breed genetic variation as a proportion of the total genetic variation, and g22, measuring the between-breed genetic variation as a proportion of the immediately selectable genetic variation, were estimated as 0·28 and 0·61 for food conversion efficiency and 0·25 and 0·57 for relative growth rate. Thus, for all three traits, despite their low CVb and t2 values, between-breed selection would be useful prior to within-breed selection.

Food intake, growth, maintenance and food conversion efficiency in the gilthead sea bream (Sparus auratus)

Aquaculture ◽  
1986 ◽  
Vol 51 (3-4) ◽  
pp. 217-224 ◽  
Author(s):  
S. Klaoudatos ◽  
J. Apostolopoulos
Keyword(s):  
Food Intake ◽  
Conversion Efficiency ◽  
Gilthead Sea Bream ◽  
Sea Bream ◽  
Food Conversion ◽  
Sparus Auratus ◽  
Food Conversion Efficiency

Breed and sex differences in equally mature sheep and goats 1. Growth and food intake

1987 ◽  
Vol 45 (2) ◽  
pp. 239-260 ◽  
Author(s):  
M. L. Thonney ◽  
St C. S. Taylor ◽  
T. H. McClelland
Keyword(s):  
Food Intake ◽  
Conversion Efficiency ◽  
Mammalian Species ◽  
The Body ◽  
Food Conversion ◽  
Size Scaling ◽  
Daily Food ◽  
Fleece Weight ◽  
Mature Size ◽  
Food Conversion Efficiency

ABSTRACTGenetic size-scaling accounts for most of the variation found among mammalian species in food intake and growth rate, with food conversion efficiency independent of the body size of the species. Is the same true of breeds and strains within species?Animals from Soay, Welsh Mountain, Southdown, Finish Landrace, Jacob, Wiltshire Horn and Oxford Down sheep breeds and from a breed of feral goats were grown to 0·40, 0·52, 0·64 or 0·76 of the mean mature weight of their breed and sex. Food was offered ad libitum and individually recorded.Allometric growth coefficients were obtained for fleece weight, femur weight and femur length. Fleece was late maturing and femur early.Breed and sex size-scaling coefficients, obtained by regression of breed and sex means on mature size, were similar to those found at the species level for age from conception to slaughter, time taken to mature and food conversion efficiency. Coefficients were higher than expected for total and daily food consumption, especially at early stages of maturity. Most breed coefficients were close to expectation while sex coefficients were somewhat higher than expected.There were significant breed deviations: Welsh Mountain, Oxford Down and probably Soay sheep required less time and Jacob sheep and feral goats required more time to mature than expected from differences in mature size. Soay and Welsh Mountain sheep appeared to be more efficient and feral goats and Jacob sheep less efficient food converters over the same maturity interval.

Selection indices to improve the efficiency of lean meat production in cattle

1986 ◽  
Vol 42 (2) ◽  
pp. 183-193 ◽  
Author(s):  
G. Simm ◽  
C. Smith ◽  
J. H. D. Prescott
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Conversion Efficiency ◽  
Breeding Value ◽  
Meat Production ◽  
Food Conversion ◽  
Lean Meat ◽  
Selection Indices ◽  
Efficiency Of Selection ◽  
Food Conversion Efficiency

ABSTRACTSelection indices to improve the efficiency of lean meat production in cattle were derived with an aggregate breeding value which comprised growth rate, food conversion efficiency, killing-out proportion and carcass lean proportion. Index measurements were growth rate, food conversion efficiency and ultrasonic fat area. Relative economic values of traits in the aggregate breeding value were calculated for an 18/20-month beef system, assuming a fixed national output of lean meat. Literature estimates of phenotypic and genetic parameters were used. Two indices were derived, one with a complete restriction on genetic changes in birth weight, and the other without restriction. Correlations between the index and the aggregate breeding value were 0·53 for the restricted index, and 0·57 for the unrestricted index. The maximum proportional reduction in expected economic response, due to complete restriction of birth weight was about 0·08. Selection on either index would actually lead to a slight decrease in carcass lean proportion, but this was less than the decrease expected from selection solely on growth rate. Correlations between the indices and the aggregate breeding value (measuring the accuracy of selection) fell by only about 0·01 when ultrasonic measurements were omitted from the index, but fell by about 0·09 when food conversion efficiency was omitted. Sensitivity of the indices to changes in parameters was also examined. With proportional changes of ±0·5 in individual economic weights, or absolute changes of ±0·2 in genetic correlations or −0·2 in heritabilities, the efficiency of selection ranged from 0·93 to 1·00.

The early weaning of pigs V. The inclusion of digestive enzymes and antibiotics in diets for pigs weaned at 6–7 lb. live weight

1959 ◽  
Vol 53 (1) ◽  
pp. 130-135 ◽  
Author(s):  
A. F. C. Calder ◽  
G. A. Lodge ◽  
R. Blair
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Live Weight ◽  
Food Conversion ◽  
Or Efficiency ◽  
Rate Of Growth ◽  
Reduced Rate ◽  
Second Period ◽  
Harmful Effects ◽  
Food Conversion Efficiency

1. Dry-meal diets for pigs weaned at 6–7 lb. mean live weight and 6·9 days mean age were supplemented with antibiotic, pepsin and an α-amylase preparation according to a factorial design involving sixty-four pigs on eight treatments. Antibiotic was included in the respective diets from weaning to 40 lb. live weight and the enzymes from weaning to 25 lb. live weight.2. Antibiotic supplementation gave a 12·5% increase in rate of growth from weaning to 40 lb. P < 0·001) by reducing the incidence of scour and increasing food consumption from weaning to 25 lb. Antibiotic exerted no effect upon efficiency of food conversion.3. Pepsin supplementation increased the incidence of scour and reduced rate of growth by 3·7% whilst being fed (P < 0·1) and by 8·6% after it was omitted at 25 lb. live weight (P < 0·01). Efficiency of food conversion was reduced by 5·5% when pepsin was fed (P < 0·05) and by 4·6% after it was omitted at 25 lb. live weight (P < 0·1).4. α-Amylase appeared to exert little influence upon either growth rate or efficiency of food conversion except in the presence of pepsin. It appeared to counteract the harmful effects of pepsin on growth rate from weaning to 25 lb. and on food conversion efficiency from 25 to 40 lb. This resulted in a 5·5% increase in growth rate during the first period (P < 0·01) and 5·7% improvement in food conversion efficiency during the second period (P < 0·05).5. The overall effects of antibiotic, pepsin and α-amylase supplementation upon time taken to reach 40 lb. live weight were a reduction of 5·6 days, an increase of 3·8 days and a reduction of 3·9 days, respectively.

Oxygen Requirements for Growth of Young Coho (Oncorhynchus kisutch) and Sockeye (O. nerka) Salmon at 15 °C

1981 ◽  
Vol 38 (4) ◽  
pp. 399-404 ◽  
Author(s):  
J. R. Brett ◽  
J. M. Blackburn
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Sockeye Salmon ◽  
Critical Level ◽  
Limiting Factor ◽  
Adaptive Mechanism ◽  
Food Conversion ◽  
Lower Oxygen ◽  
Oxygen Requirements ◽  
Food Conversion Efficiency

The growth rate and food conversion efficiency of young coho and sockeye salmon on a full ration were determined in freshwater at oxygen concentrations ranging from 2 to 15 mg/L (15 °C). The data, and a reanalysis of selected published records for bass, carp, and coho, were examined critically in relation to the Limiting Factor hypothesis. It was concluded for all species that above a critical level ranging from 4.0 to 4.5 mg O2/L, growth and conversion efficiency were not limited when tested for relatively short periods (6–8 wk) under the pristine conditions of laboratory tanks. A slight but significant trend to exhibit higher hematocrits at lower oxygen levels revealed the possible presence of an adaptive mechanism for improved respiratory capacity at subcritical oxygen concentrations.Key words: limiting oxygen, growth rate, blood hematocrits, salmon tolerance

Responses in growth, food intake and food conversion efficiency to different dietary protein concentrations in meat‐type lines of Japanese quail

1997 ◽  
Vol 38 (5) ◽  
pp. 564-570 ◽  
Author(s):  
L. Hyánková ◽  
L. D#akedková ◽  
H. Knížetová ◽  
D. Klecker
Keyword(s):  
Food Intake ◽  
Conversion Efficiency ◽  
Japanese Quail ◽  
Dietary Protein ◽  
Food Conversion ◽  
Food Conversion Efficiency ◽  
Meat Type
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