The Effects of Sublethal Concentrations of Whole Bleached Kraftmill Effluent on the Growth and Food Conversion Efficiency of Underyearling Sockeye Salmon (Oncorhynchus nerka)

1972 ◽  
Vol 29 (11) ◽  
pp. 1555-1563 ◽  
Author(s):  
P. W. Webb ◽  
J. R. Brett
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Sockeye Salmon ◽  
Condition Factor ◽  
Dry Weight ◽  
Food Conversion ◽  
Response Curves ◽  
Threshold Response ◽  
Exposure Temperature ◽  
Sublethal Concentrations

Changes in growth rate and gross conversion efficiency were measured for underyearling sockeye salmon during and after exposure to full bleached kraftmill effluent (BKME). Five groups of fish were exposed for 56 days to 0, 1.0, 2.5, 10, and 25% BKME (v/v). Fresh 24-hr composite effluent at pH 6.8 was used daily after filtering. Growth was followed for a further 56 days after BKME exposure. Temperature was held at 15 C and dissolved oxygen between 90 and 100% air saturation. Growth rate and conversion efficiency were unaffected at 1.0 and 2.5% BKME. Reduced mean growth rate and conversion efficiency at 10% BKME were not statistically significant from controls but were considered to be biologically important in estimating threshold response levels. Significant reductions were found at 25% BKME. No recovery in retarded growth was found after exposure to BKME. Condition factor and percentage dry weight were not affected. It was concluded from computed response curves that the EC50 of the effluent was approximately 3.7% (v/v).

Effects of Sublethal Concentrations of Sodium Pentachlorophenate on Growth Rate, Food Conversion Efficiency, and Swimming Performance in Underyearling Sockeye Salmon (Oncorhynchus nerka)

1973 ◽  
Vol 30 (4) ◽  
pp. 499-507 ◽  
Author(s):  
P. W. Webb ◽  
J. R. Brett
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Sockeye Salmon ◽  
Swimming Performance ◽  
Oncorhynchus Nerka ◽  
Dry Weight ◽  
Food Conversion ◽  
Ration Level ◽  
Sodium Pentachlorophenate ◽  
Sublethal Concentrations

Tests were performed at 15 C, pH 6.8, and dissolved oxygen values of 90–100% air saturation. Growth rate and conversion efficiency were measured by feeding a ration level of 15% body dry weight/day to underyearling sockeye salmon (Oncorhynchus nerka) held at sodium pentachlorophenate (PCP) concentrations of 0, 1.14, 1.99, 3.49, 7.16, 13.60, 27.73, 31.57, and 47.18 ppb. Swimming performance was measured at PCP concentrations of 0, 7.21, 19.00, and 50.00 ppb. The 96-hr LC50 was 63 ppb PCP. Growth rate and conversion efficiency were almost equally affected by PCP, the EC50 values being 1.74 ppb for growth rate and 1.80 ppb for conversion efficiency. This is approximately 2.8% of the 96-hr LC50. Swimming performance was unaffected by PCP at the concentrations used.

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

The relative protein and energy requirements of boars, gilts and barrows

1977 ◽  
Vol 17 (87) ◽  
pp. 574 ◽  
Author(s):  
M Taverner ◽  
RG Campbell ◽  
RH King
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Dietary Protein ◽  
Protein Level ◽  
Crude Protein ◽  
Regression Equations ◽  
Food Conversion ◽  
Response Curves ◽  
Digestible Energy ◽  
Food Conversion Efficiency

Two experiments were conducted to study the response of boars, gilts and barrows to increasing levels of dietary crude protein and digestible energy. In the first experiment boars, gilts and barrows were fed diets ranging in crude protein from 14.6 to 22.7 per cent in restrictive amounts between 20 and 70 kg liveweight. Growth rate and food conversion efficiency measurements ranked the sexes in order of superiority as boars, gilts and barrows. Boars contained more lean in their hams than gilts or barrows and had lower back fat measurements than barrows. Although analysis of variance indicated there was no significant sex by protein interaction, the multiple regression equations of growth rate and the proportion of lean in the ham for the three sexes were significantly different from one another. The response curves based on the regression equations indicated that for optimum growth, boars and gilts required 19.6 per cent crude protein whereas barrows required only 18.4 per cent crude protein. The proportion of lean in the ham was maximized with 21 per cent crude protein for boars and 20 per cent crude protein for the gilts and barrows. There was a significant quadratic relationship between economic returns and dietary protein. The relationship was the same for boars and gilts and significantly different from that for barrows; returns were maximized at approximately the same protein level as growth rate for the three sexes. In the second experiment, 30 boars and 30 gilts were allocated to 30 treatment groups involving the two sexes, three levels of digestible energy (14.59, 15.51 and 16.22 MJ kg-1) and five levels of crude protein (18.2, 19.4, 20.6, 21.8 and 23.0 per cent). All diets were fed restrictively and pig performance was compared over the liveweight range 20 to 80 kg. Boars grew significantly faster, had a significantly lower food conversion ratio and produced leaner carcases than gilts. Increasing the DE level of the diet improved growth rate and food conversion efficiency but reduced carcase quality. Dietary protein level had no effect on any performance or carcase quality measurement.

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.

Effect on pig performance of varying the level of meat meal in cereal grain-meat meal diets

1976 ◽  
Vol 16 (81) ◽  
pp. 478
Author(s):  
VF Fagan ◽  
PR Gillis
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Optimum Level ◽  
Optimum Growth ◽  
Food Conversion ◽  
Lean Meat ◽  
Stage Of Development ◽  
Meat Meal ◽  
Cereal Grain ◽  
Food Conversion Efficiency

A pig feeding experiment was conducted in which six levels of meat meal ranging from 5 per cent to 30 per cent in increments of 5 per cent were fed throughout the experiment. Two additional treatments were included in which an initial meat meal level of 20 per cent was changed to 10 per cent in one treatment (20-10 per cent) and 0 per cent in the other (20-0 per cent) at 54.6 kg liveweight. The optimum level of meat meal was found to vary with the stage of development of the animals. At 30 kg liveweight optimum growth rate and food conversion efficiency occurred at a meat meal level of approximately 21.0 per cent. At 70 kg liveweight optimum growth rate and food conversion efficiency occurred on a diet with approximately 14.5 per cent meat meal. Reducing the level of meat meal at 54.6 kg from 20 per cent to 10 per cent had no adverse effect on any of the attributes measured. However, the reduction from 20 per cent to 0 per cent had a highly significant depressive effect on growth rate, food conversion efficiency and lean meat development. For the treatments fed at constant levels of meat meal, fat cover decreased with increasing meat meal whereas lean meat development increased with increasing meat meal up to 25 per cent but then showed a decline at 30 per cent.

scholarly journals Quality of Nephrops as food for Atlantic cod (Gadus morhua L.) with possible implications for fisheries management

2004 ◽  
Vol 61 (6) ◽  
pp. 983-991 ◽  
Author(s):  
Björn Björnsson ◽  
Maria Álvaro Dongala Dombaxe
Keyword(s):  
Growth Rate ◽  
Gadus Morhua ◽  
Specific Growth ◽  
Condition Factor ◽  
Atlantic Cod ◽  
Gonadosomatic Index ◽  
Conversion Ratio ◽  
Food Conversion ◽  
The Mean

Abstract Nephrops was found to be of low quality as food for cod. In a laboratory experiment the mean specific growth rate of 1 kg cod was 0.184 and 0.415% d−1 when fed to satiation on Nephrops and capelin, respectively. This large difference in growth rate resulted not only from less intake of Nephrops (1.19 kg cod−1) than capelin (1.55 kg cod−1) but also because more Nephrops (4.6 kg) than capelin (2.2 kg) were required to produce each kilogramme of cod. Higher food conversion ratio was consistent with lower fat content of Nephrops (1.3%) than capelin (9.2%) but the exoskeleton also reduced the digestion rate of Nephrops. In the groups where Nephrops and capelin of equal mean weight were offered simultaneously, 40% of the diet consisted of Nephrops during the first week and 10% during the final seven weeks of the experiment. At the end of the experiment, condition factor, liver index, and gonadosomatic index were significantly lower for cod fed on Nephrops (0.967, 5.7, 7.1, respectively) than for those fed on capelin (1.086, 15.8, 11.2, respectively). These results suggests that predation by cod on Nephrops might be reduced by regular release of capelin or other similar food in the distributional areas of Nephrops.

The food conversion efficiency in lambs of two crosses of sheep

1967 ◽  
Vol 7 (26) ◽  
pp. 199 ◽  
Author(s):  
ME Bourke
Keyword(s):  
Growth Rate ◽  
Organic Matter ◽  
Conversion Efficiency ◽  
Animal Tissue ◽  
Food Conversion ◽  
Factors Associated ◽  
Digestible Organic Matter ◽  
High Level ◽  
Food Conversion Efficiency

The experiment investigated factors associated with differences in growth rate from birth to seven weeks, by two crossbreeds of lamb. The Dorset Horn x Border Leicester-Merino grew at 0.18 kg per day, and the Dorset Horn x Merino grew at 0.14 kg per day (P<0.001) although both crosses consumed the same digestible organic matter intake. Thus the second cross was significantly more efficient (P<0.05) than the first cross. Two levels of milk were also fed to both crosses and, although the high level improved growth rate (P <0.001), it did not effect the efficiency of conversion of food to animal tissue.

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