The effects of Salinity and Feeding Levels on the Growth Rate and Food Conversion Efficiency of the Shrimp Penaeus Aztecus

2009 ◽  
Vol 3 (1-4) ◽  
pp. 267-283 ◽  
Author(s):  
A. Venkataramaiah ◽  
G. J. Lakshmi ◽  
Gordon Gunter
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Food Conversion ◽  
Penaeus Aztecus ◽  
Food Conversion Efficiency

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

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.

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.

The early weaning of pigs IV. Comparisons of levels of antibiotic and sources of protein in diets for pigs weaned at 9 lb. live weight

1959 ◽  
Vol 53 (1) ◽  
pp. 125-129 ◽  
Author(s):  
I. A. M. Lucas ◽  
A. F. C. Calder ◽  
H. Smith
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Fish Meal ◽  
Skim Milk ◽  
Live Weight ◽  
Standard Diet ◽  
Food Conversion ◽  
Carry Over ◽  
Antibiotic Level ◽  
Food Conversion Efficiency

In Exp. 1 groups of piglets weaned at about 9 lb. live weight were fed one of three 29% protein diets up to 26 lb. live weight. These diets A, B and C contained 42, 20 and 0% dried skim milk, 15, 25 and 32% white fish meal and 22, 34 and 47% rolled oat groats, respectively. At 26 lb. all pigs were changed over to a standard 17% protein diet.The replacement of about one-half of the dried skim milk in diet A with white fish meal and rolled oat groats caused 4% faster growth from 9 to 26 lb. live weight, but the replacement of all the dried skim milk caused growth over the same weight range to be slower by 6%. The quadratic component of these treatment effects was significant at P < 0·0·25. The slower growth with the diet containing no dried skim milk was associated with a lower daily consumption of feed, and the improved growth rate with the intermediate skim milk level was probably associated with an improvement in food conversion efficiency. Treatment differences in food conversion efficiency before 26 lb. live weight, however, were not statistically significant. There were no significant carry-over effects of treatments upon performance from 26 to 50 lb. live weight.In Exp. 2 piglets weaned at about 9 lb. live weight were fed individually up to 40 lb. live weight. From 9 to 26 lb. antibiotic levels of 22, 45, 67 and 90 mg./lb. feed were compared, but from 26 to 40 lb. all pigs were fed a standard diet containing 18 mg. antibiotic/lb. In diets fed before 26 lb. the antibiotic was a mixture of 3 parts by weight chlortetracycline: 1 part by weight procaine penicillin. From 26 to 40 lb. live weight the antibiotic fed was chlortetracycline.Before 26 lb. live weight increases in antibiotic level caused average increases of up to 5% in growth rate and 4% in food conversion efficiency. Taken in conjunction with previous results the improvement in growth rate in favour of the highest antibiotic level was significant at P < 0·05.There were no carry-over effects of antibiotic level on growth rate from 26 to 40 lb., but there was the suggestion of a linear trend whereby each increase in antibiotic level fed before 26 lb. caused a decrease in food conversion efficiency between 26 and 401b. (P = 0·10).The results are discussed in relation to financial economies which may be made in diets for early weaned pigs.

The effects of quantity and distribution of milk substitute on the performance and carcass measurements of artificially reared lambs

1975 ◽  
Vol 20 (1) ◽  
pp. 111-121 ◽  
Author(s):  
P. D. Penning ◽  
T. T. Treacher
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Live Weight ◽  
Previous Treatment ◽  
Food Conversion ◽  
Milk Substitute ◽  
Weaning Age ◽  
Daily Allowance ◽  
The Mean ◽  
Food Conversion Efficiency

SUMMARYTwenty-seven groups of Finnish Landrace × Dorset Horn lambs each of 2 castrated males and 2 females were offered daily quantities of 180, 248 or 343 g of milk substitute dry matter (DM) for 21, 29 or 40 days. Concentrate pellets were available ad libitum and from 22 days of age 150 g of hay per week was offered. When the mean live weight of a group reached 35 kg two castrates and one female from each group were slaughtered and the carcasses appraised.The growth rate and daily concentrate intake of lambs from 48 days of age until slaughter (reported -in this paper) were not affected by previous treatment, but lambs weaned at 40 days had a higher food conversion efficiency in this period (0·266 kg gain/kg feed DM) than those weaned at 21 days (0·244) or 29 days (0·232).Delaying weaning from 21 to 29 and 40 days reduced overall concentrate DM intake from birth to slaughter (from 88·15 to 81·09 and 73·39 kg) but increased growth rate (261, 276 and 288 g/day) and the conversion of total DM consumed to live weight (0·300, 0·311 and 0·350 kg/kg). Increasing the daily allowance of milk substitute from 180 to 248 and 343 g/day also reduced total concentrate intake (84·18, 80·74 and 77·71 kg). Growth rate and food conversion efficiency tended to increase and concentrate DM intake to decrease when the same total quantity of milk substitute was given over a longer period. Castrated males grew faster than females (290 v. 260 g/day).Weaning age generally had a greater effect than daily allowance of milk substitute on carcass measurements. Fat in the carcass tended to increase with increasing weaning age and significant interactions between daily allowance of milk substitute and weaning age were found for some carcass measurements.

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.

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