Optimum Protein Level Research Articles

유기 산란계 에너지.단백질 수준이 산란 생산성 및 계란 품질에 미치는 영향

본 연구는 유기 산란계의 산란기 영양적 특성을 구명하고 산란기 성장기별 에너지와 단백질의 적정 수준을 설정하기 위해 실시하였다. 시험에 사용된 공시축은 산란계(Hy-Line) 360수이었으며, 시험 전 기간 평사에서 사육하였다. 시험 사료는 옥수수와 대두박 위주의 유기 사료를 이용하였다. 시험구 배치는 에너지 수준 3수준(2,800, 3,080, 3,360 kcal/kg), 단백질 수준 2수준(16, 18%)인 6처리 4반복 반복당 15수씩 총 360수를 공시하였다. 시험 사료는 산란 기간 동안 자유 채식시켰고 물은 자유로이 마시도록 하였으며, 점등은 자연 일조를 포함하여 14시간을 넘지 않도록 하였으며, 횃대와 산란 상자를 만들어 주었다. 그 외의 사양 관리는 유기 양계 규정에 맞도록 준수하였다. 산란기 생산성은 에너지 수준을 달리했을 때 산란율, 난중 및 산란량에서 NRC 에너지 수순과 비슷한 2,800 kcal/kg 수준이 3,080 및 3,360 kcal/kg 수준에 비해 시험 전 기간에 걸쳐 유의적으로 높은 생산성을 보였다(P< 0.05). 계란의 난각 강도는 에너지와 단백질 수준간 통계적인 유의차는 없었으나, 난각 두께는 50, 70주령에 에너지 수준이 높은 3,360 kcal/kg에서 유의적으로 두꺼웠다. 혈액생화학은 Total Cholesterol의 수치가 에너지 수준의 증가와 함께 유의적으로 높아졌다(P<0.05). 본 연구의 결과를 종합해 보면, 유기 산란계의 산란기 적정 에너지와 단백질 수준은 ME 2,800 kcal/kg, CP 16%에서 산란 생산성 및 계란의 품질을 높게 유지하였다. This experiment was conducted to determine optimum dietary levels of dietary energy and protein for laying performance and egg quality in organic laying hens. In a <TEX>$2{\times}3$</TEX> factorial arrangement, 360 Hy-Line pullets (21 wk of age) were randomly assigned to experimental diets with 2,800, 3,080, and 3,360 kcal of ME/kg of diet, each containing 16 and 18% CP, respectively. Each dietary treatment was replicated 4 times, and feed and water were provided ad libitum. Experimental birds were raised in floor and received 14h of light throughout 52 weeks of experimental period. The birds were observed for feed consumption, egg production, egg weight, egg mass, feed conversion ratio, Haugh unit, shell thickness, and shell color at 30, 50, and 70 wk of age. Egg production, egg weight, and egg mass were higher (P<0.05) in hens receiving diets with 2,800 kcal/kg of ME/kg of feed than those fed diets containing 3,080 and 3,360 kcal of ME/kg of diets. Eggshell breaking strengths were not significantly different among the dietary ME and CP concentrations. Eggshell thickness was higher (P<0.05) in hens receiving diets with 3,360 kcal of ME/kg of feed than those fed diets containing 2,800 and 3,080 kcal of ME/kg of diets at 50 and 70 week. With increasing in dietary energy levels, the concentrations of blood total cholesterol were also significantly increased. Overall, the laying hens fed organic diet of 2,800 kcal ME/kg and 16% CP showed superior egg production than those of other dietary regimens.

The Effect of Cucumber mosaic virus 2b Protein to Transient Expression and Transgene Silencing Mediated by Agro-infiltration

The transient and rapid expression system of a foreign protein in planta is a very useful technique in biotechnology application. We have investigated optimum condition of Agrobacterium-infiltration technique in which expression level of foreign proteins were maximized without detrimental effects on plants using GFP and Cucumber mosaic virus 2b protein, which is known as an enhancer of gene expression and a suppressor of post-transcriptional gene silencing(PTGS). The optimum expression level of both RNA and protein of GFP with minimum leaf impairment was obtained at

Modulation of key metabolic enzyme of Labeo rohita (Hamilton) juvenile: effect of dietary starch type, protein level and exogenous α-amylase in the diet

A 60-day feeding trial was conducted to delineate the effect of both gelatinized (G) and non-gelatinized (NG) corn with or without supplementation of exogenous alpha-amylase, either at optimum (35%) or sub-optimum (27%) protein levels, on blood glucose, and the key metabolic enzymes of glycolysis (hexokinase, HK), gluconeogenesis (glucose-6 phosphatase, G6Pase and fructose-1,6 bisphosphatase, FBPase), lipogenesis (glucose-6 phosphate dehydrogenase, G6PD) and amino acid metabolism (alanine amino transferase, ALT and aspartate amino transferase, AST) in Labeo rohita. Three hundred and sixty juveniles (average weight 10 +/- 0.15 g) were randomly distributed into 12 treatment groups with each of two replicates. Twelve semi-purified diets containing either 35 or 27% crude protein were prepared by including G or NG corn as carbohydrate source with different levels of microbial alpha-amylase (0, 50, 100 and 150 mg kg(-1)). The G corn fed groups showed significantly higher (P < 0.05) blood glucose and G6PD activity, whereas G6Pase, FBPase, ALT and AST activity in liver was higher in the NG corn fed group. Dietary corn type, alpha-amylase level in diet or their interaction had no significant effect (P > 0.05) on liver HK activity, but the optimum crude protein (35%) fed group showed higher HK activity than their low protein counterparts. The sub-optimum crude protein (27%) fed group showed significantly higher (P < 0.05) G6PD activity than the optimum protein fed group, whereas the reverse trend was observed for HK, G6Pase, FBPase, ALT and AST activity. Addition of 50 mg alpha-amylase kg(-1) feed showed increased blood glucose and G6PD activity of the NG corn fed group, whereas the reverse trend was found for G6Pase, FBPase, ALT and AST activity in liver, which was similar to that of the G or NG corn supplemented with 100/150 mg alpha-amylase kg(-1) feed. Data on enzyme activities suggest that NG corn in the diet significantly induced more gluconeogenic and amino acid metabolic enzyme activity, whereas G corn induced increased lipogenic enzyme activity. Increased amino acid catabolic enzyme (ALT and AST) activity was observed either at optimum protein (35%) irrespective of corn type or NG corn without supplementation of alpha-amylase irrespective of protein level in the diet.

The effects of feeding level upon protein and fat deposition in Iberian heavy pigs

Eighteen Iberian barrows of 100 kg initial BW were used in a comparative slaughter experiment to investigate the effects of feeding level (FL; 0.70 and 0.95 × ad libitum) on growth, protein- and fat-deposition rates and body composition. They were fed on a diet supplying the optimum level of digestible ideal protein:ME ratio (4.82 g/MJ) and slaughtered at 150 kg BW. The apparent digestibility of DM, OM, total N and GE, and the ME:GE and ME:DE ratios were not affected by FL. The average daily gain increased with the increase in FL (691 and 918 g/day respectively). Neither the gain:feed (g/g DM) nor the gain:ME intake (g/MJ) ratios were significantly affected however. An energy cost of 59.9 kJ ME/g gain was calculated. The rate of whole-body protein deposition was not significantly altered by FL. On average it reached 80 g/day. The pigs fed at the lowest level exhibited lower fat deposition ( P < 0.01) and total energy retention ( P < 0.01) than those in the group subjected to only a slight feed restriction. The overall efficiency of utilization of ME for energy gain (ER:ME intake) remained at 0.363 on average, irrespective of the FL imposed. Relative proportions of energy retained as protein and fat were not statistically altered by changes in FL. Mean values for ERP:ER and ERF:ER were 0.100 and 0.903 respectively. No differences between treatments were observed in fat, ash, water or energy content of the whole-body (g/kg) at 150 kg empty BW, the mean values ( n = 12) being 512 ± 8.5, 27.6 ± 0.63 and 353 ± 6.7 g/kg for fat, ash and water respectively and 22.90 ± 0.31 MJ/kg for energy. Nevertheless, the proportion of protein tended to decline with the increase in FL (111 vs 104; P = 0.069). At 150 kg the Iberian pigs contained more fat and energy and less ash and water than at 100 kg. Whilst the percentage of lean tissue decreased significantly ( P < 0.05) and protein content in the carcass showed a strong tendency to decline in the pigs fed close to ad libitum (104 vs 96; P = 0.056), the proportions of fat, ash, water and energy remained constant at 564 ± 9.0, 22.2 ± 0.91, 312 ± 6.6 g/kg, and 24.82 ± 0.32 MJ/kg, respectively. It was concluded that a degree of feed restriction may result in a discernible improvement in carcass quality.

Optimum protein level for growth in juvenile bullfrog ( Rana catesbeiana Shaw, 1802)

An estimate was made of the optimum protein level in growth diets for bullfrog Rana catesbeiana. A nested design of six treatments with three replicates per treatment was used. Juvenile bullfrogs (8.84 ± 1.42 g average initial weight) were fed in lots at 6% body weight per day with six practical diets containing 20, 28, 34, 42 50 or 58% crude protein from fish meal. Each batch contained 12 frogs placed randomly in plastic cages with an automatic water sprinkler system to keep the animals wet and the cages clean. Cages were installed under a controlled environment: 28 °C temperature; 100% relative humidity; and 14L:10D photoperiod. The diets were assigned randomly to the cages. Results were evaluated in terms of survival, growth and feed efficiency. All the treatments showed 83% survival except the 28% protein diet, which had 60.44%. Productive performance tended to improve as protein level increased. The greatest growth was observed in the 58% protein diet, although this was not statistically different from the 42 and 50% protein diets. Feed conversion ratio (FCR) also improved as dietary protein level increased, with the best FCR in the 58% protein diet, although this was not significantly different from the 42 and 50% protein diets. Optimum protein level was estimated using a second-order quadratic regression using weight gain (%) and established as 39.21% crude protein at a protein:energy ratio of 81.34 mg P/kcal. Under the experimental conditions applied, a 40% crude protein level is recommended for growth in juvenile R. catesbeiana.

Effects of dietary protein and lipid levels on growth and body composition of silver dollar (Metynnis schreitmuellerei) fry

The aims of this study were to determine the effects of different levels of protein and lipid on the growth and body composition of fry of the silver dollar, Metynnis schreitmuelleri (Ahl). The fry were first fed diets containing 25, 35, 45, or 55% protein to determine the optimum protein level. The best growth, body composition, protein efficiency ratio, and food conversion ratio were obtained with the 35% protein diet. The fry were next fed diets containing 35% protein and 0, 3, 6, 9, or 12% lipid. The best growth, body composition, protein efficiency ratio, and food conver- sion ratio occurred with the diet containing 35% protein and 6% lipid.

Effect of protein levels on growth, feed utilization, nitrogen and energy budget in juvenile southern flounder, Paralichthys lethostigma

A feeding trial with five crude protein levels (549, 513, 472, 445 and 399 g kg−1) was conducted to investigate the optimum protein level in diets of juvenile southern flounder (Paralichthys lethostigma). Budgets of nitrogen and energy were discussed. Fish (initial weight 32.9 ± 0.5 g fish−1, mean ± SD) were fed the experimental diets to satiation twice daily for 61 days. Protein levels affected specific growth rate in wet weight (SGRW) and protein (SGRP) significantly. SGRW and SGRP were highest at 512.5 g kg−1 protein level. SGRW was positively correlated to growth nitrogen (GN), growth energy (GE), nitrogen digestibility, energy digestibility, amount of digestible nitrogen and amount of digestible energy. Faecal nitrogen (FN) and faecal energy (FE) were affected significantly with trends contrary to SGRW. The nitrogen budget was described by the equation 100CN = 2.1FN + 34.4UN + 63.5GN (CN, nitrogen intake; UN, excretion nitrogen). The energy budget was 100IE = 4.04FE +3.32UE + 54.35GE + 38.30ME (IE, gross energy intake; UE, excretion energy; ME, metabolizable energy). The average proportion of GE and ME in assimilated energy (AE) was described by the equation 100AE = 58.65GE + 41.35ME.

사료의 조단백질 수준이 육성기 흑염소의 발육과 육질에 미치는 영향

본 시험은 사료의 조단백질 수준이 육성기 흑염소의 발육과 육질에 미치는 영향을 구명하기 하기 위하여 흑염소 육성축 수컷 40두를 공시하여 조단백질 수준을 각각 달리하여 2004년 4월 19일부터 2004년 9월 13일까지 시험을 실시하였으며 그 결과는 다음과 같다. 일당증체량은 CP 14%, CP 18%구가 각각 84.0, 83.0g으로 CP 12%구 69.2g 보다 높았으며(P<0.05) CP 16%구는 80.9g으로 비슷한 경향이었다. 1일 사료섭취량은 농후사료와 볏짚 각각 590g, 45g 내외로 처리구간에 비슷하였고 증체 g당 사료요구율은 CP 14%, 16%, 18%구간에는 7.0-7.3으로 비슷하였으나 CP 12%구는 다소 높은 경향이었다. 도체율은 CP 12%구가 61.7%로 CP 14와 CP 18%구 보다 높았으나(P<0.05) CP 16%구와는 비슷하였다. 정육율은 CP 16%가 51.7%로 CP 12와 CP 14%구 보다 높았다(P<0.05). 지방율은 CP 12%구가 12.8% 높았으며(P<0.05) 뼈율은 17.0% 내외로 처리구간에 비슷하였다. 고기의 물리적 특성인 전단력과 가열 감량은 CP 16%구와 CP 14%구가 다른 처리구보다 다소 낮은 경향이었고 보수력은 CP 16%구가 CP 18%구 보다 높았다(P<0.05). 관능검사결과 다즙성은 CP 16%구가 CP 12%구 보다 우수하였으며(P<0.05) 연도도 다른 처리구에 비해 우수한 경향이었다. 이러한 결과를 종합적으로 고려할 때 육성기 흑염소의 발육과 육질개선을 위한 사료의 적정 조단백질 수준은 14-16%가 적합한 것으로 사료된다. This study was conducted to investigate the optimal CP level in growing goat kids. Forty male goats were divided into four treatment groups fed diets containing CP 12, 14, 16, and 18% of concentrate feed, and rice straw, respectively. Results are summarized as follows. Average daily gain’s(ADG) of groups fed diets with CP 14% and CP 18% were 84.0 and 83.0g/d each, which were higher than group fed diets with CP 12% grown at 69.2g of ADG(P<0.05). Daily feed intakes of concentrate and rice straw were 590g and 45g each and there was no difference found between treatments. The amounts of feed required for body weight gain(g) were similar in the range of 7.0-7.3 for groups fed diets with CP 14%, 16% or 18%. But the group fed diets with CP 12% required somewhat more feed for gain at 8.8g. Dressing percentage of groups fed diet with CP 12% was 61.7%, which was higher than groups fed diets with CP 14% or CP 18%(P<0.05) but similar to that fed diet with CP 16%. Meat percentage from goats fed diet with CP 16% was 51.7%, which were higher than goats fed diets with CP 12% or CP 14%(P<0.05). Fat deposition of CP 12% group was higher than the other groups(P<0.05). Percentage of bone weight averaged 17.0% without any difference among treatment groups. Shear force and cooking loss, which are physical properties of goat meats, were lower in CP 16% and CP 14% groups than the other two groups. Water holding capacity of goats meats from CP 16% was higher than those from CP 18% group(P<0.05). Results from panel test showed that juiciness of meats from CP 16% group was higher than those from CP 12% group(P<0.05). Meats from CP 16% also was tested to be more tender than meats from the other groups. Results from this work suggest that the optimum crude protein level in growing goat's concentrate is 14-16% and that increase above this level seems not to improve meat production.

Solubility and peptide profile affect the utilization of dietary protein by common carp (Cyprinus carpio) during early larval stages

The present work aimed at evaluating whether solubility and peptide profile of dietary protein can affect survival and growth performance of common carp during early stages of life. Water-insoluble casein and two forms of soluble casein (non-hydrolysed and hydrolysed) were used as protein sources at different proportions in the experimental diets for first-feeding carp larvae. When provided as the only protein source water-insoluble casein led to high mortality and depressed growth after 21 days. The partial or total substitution of water-insoluble casein by soluble non-hydrolysed casein effectively improved survival and enhanced growth of larvae. An optimum level of soluble non-hydrolysed protein was found at 25% of total protein. The addition of some hydrolysed casein (25% of soluble protein) further improved results. However, high dietary levels of hydrolysed casein led to negative effects on larval performance, which would be related with a surplus of di-/tripeptides or/and amino acids. Protein solubility appears to have only a temporary effect on larval performance, probably related with the ontogeny of the digestive tract, since about 2 weeks after the onset of exogenous feeding larvae became able to use efficiently water-insoluble protein. Results also suggest the need for a balance in the peptide profile to optimise the utilization of dietary protein by fish larvae.

The effect of dietary crude protein level on growth, carcass and meat composition of male goat kids in Tunisia

Effects of concentrate protein content on growth performances and body composition were studied on fifteen local goat kids. All kids were male with an average body weight of 23.3 kg (S.D.=2.1 kg) at the beginning of the experiment. Animals were randomly divided into three groups of five kids each. Goats in each group received individually oat hay ad-libitum and one of three concentrates containing low, medium or high crude protein level. Low, medium, and high crude protein levels were 100, 130, and 160 g/kg of dry matter, respectively. All concentrates were isocaloric. The growth experiment lasted 12 weeks. In the following 2 weeks, digestibility was measured and then all kids were slaughtered. During the first 6 weeks of the experiment, kids fed low and medium crude protein diets gained less weight ( P<0.05) than those fed the highest protein level. In the rest of the experimental period, animals receiving the medium diet had the highest growth rate ( P<0.05). Digestibility of dry matter, organic matter, and crude protein was similar for the high and medium protein diets and was higher ( P<0.05) than that for the low diet. This same trend was found for the nitrogen balance except for the nitrogen retention. Diet content in crude protein seemed not to affect empty body and carcass weights, dressing percentage, and external (skin, head and feet) and thoracic organs (lungs and heart). However, goats fed medium protein level had the heaviest ( P<0.05) liver and gut among all animals. Muscle, bone and adipose tissue mean weights did not follow the increase of crude protein level in the diet. However, animals given medium crude protein diet had relatively more muscle ( P<0.01) and less fat ( P<0.05) than those fed high diets. Bone proportion was comparable among animals receiving the three diets. Animals fed high protein diet had more omental and mesenteric fat ( P<0.05) and total body fat in absolute ( P<0.05) and relative value ( P<0.01) than those offered the medium level, while values found for the low diet kids were intermediate. Meat of kids receiving the medium diet crude protein level was juicier than meat from other kids. It contented more protein ( P<0.05) and less fat ( P<0.01). Results from this work suggest that the optimum crude protein level in growing goats’ concentrate is approximately 130 g/kg DM and that any increase above this level seems no to improve meat production.

Effect of dietary protein level on growth and survival of juvenile freshwater crayfishCherax quadricarinatus(Decapoda: Parastacidae)

Protein requirements of juvenile freshwater crayfish Cherax quadricarinatus, with initial mean weight of 1.08 ± 0.34 g, were studied. Juveniles were fed experimental diets containing seven levels of crude protein (CP) (20, 25, 31, 37, 43, 49, and 55%) and 18.73–21.45 kJ g−1 of gross energy. The highest mean weight and specific growth rate (SGR) (P < 0.05), with values of 9.6 g, and 3.64% day−1, respectively, were achieved by feeding a diet of 31% CP. This diet resulted in a survival rate of 80% over 60 days of culture at 27 °C. The higher protein level tested (55% CP), yielded a significantly (P < 0.05) lower mean weight of 6.4 g. However, there were no significant differences in SGR among the 20, 25, and 49% CP diets. Feed Conversion Ratio (FCR) was close to 1 for all treatments except the lowest (20%) and highest (55%) CP. Optimum protein requirements were estimated by fitting mean weight gain data to a quadratic model (y = 1.142+0.484 − 0.0071x2, r2 = 0.952, P < 0.05). Optimal growth occurred with 34.2% CP, but the results suggest that optimum protein level for 1-g juvenile C. quadricarinatus is 31% in least-cost diets. The information obtained will contribute to the formulation of diets that will enhance production of C. quadricarinatus.

Effect Of Animal And Plant Protein Diets On Growth And Fecundity In Ornamental Fish, Betta Splendens (Regan)

The effects of different levels of animal and plant protein (10%, 15%, 25%, 35% and 45%) on growth and fecundity in Siamese fighting fish, Betta splendens, were tested over a period of 154 days. Fish fed 35% animal or plant protein had the highest mean body wet weight, growth rate, gonad weight and fecundity than any other tested level. Animal protein induced gonad develop- ment earlier than plant protein. Female B. splendens fed the 35% animal protein diet had a 79% higher gonad weight (87 mg wet weight) than those fed the diet with the same level of plant pro- tein (49 mg wet weight). Spawning trials showed that 35% animal or plant protein diets produced the highest number of eggs and the highest hatching rate compared to the other diets; hence, 35% animal or plant protein is considered the optimum level for B. splendens. Females fed the 35% animal protein diet laid 1044 eggs in three spawnings in contrast to 846 eggs produced by fish fed the 35% plant protein diet. The necessity of incorporating an optimum level of animal protein in the diet for maximum reproductive performance in B. splendens is discussed.

Use of the bacteria Streptococcus faecium and Lactobacillus acidophilus, and the yeast Saccharomyces cerevisiae as growth promoters in Nile tilapia ( Oreochromis niloticus)

This study evaluated the effects of three types of probiotics, two bacteria and one yeast on growth performance in Nile tilapia. Three diets were formulated containing the optimum protein level (40%) for tilapia fry: one supplemented at 0.1% with a bacterial mixture containing Streptococcus faecium and Lactobacillus acidophilus; a second supplemented at 0.1% with the yeast Saccharomyces cerevisae; and a third, a control diet without supplements. Two additional diets were formulated to contain 27% protein to serve as a stress factor, and were supplemented at 0.1% with either the bacterial probiotic mix or the yeast. The diets were fed for 9 weeks to tilapia fry stocked in 20-l tanks at two densities: a high density of 20 fry per tank as a stress factor; and a low density of 10 fry per tank. Results indicate that the fry fed with diets with a probiotics supplement exhibited greater growth than those fed with the control diet. Of the four probiotic treatments, the 40% protein diet supplemented with yeast produced the best growth performance and feed efficiency, suggesting that yeast is an appropriate growth-stimulating additive in tilapia cultivation.

Study of the optimum ideal protein level for weaned piglets

The amount of ideal protein, represented by the first limiting valine (Val), for optimising the growth performances of weaned hybrid piglets was studied. Feeds were formulated based on the ideal protein concept and on a constant essential/nonessential amino acid (AA) ratio and net energy (NE) level. The animal performance trial was composed of five dietary treatments ranging from 0.57 to 0.81% calculated apparent (app.) ileal (il.) digestible (dig.) Val. The piglets, male and female in equal numbers (11 replicates x 6 piglets/pen x 5 treatments) entered the trial at about 4 weeks old (average live weight 8.1 kg). The piglets were a cross product of Piétrain sire x hybrid dam. Feed intake and weight were recorded every two weeks until the end of the trial at 10 weeks of age (average live weight 20.6 kg). The requirement was expressed in st. il. dig. AA-units, as this unit approaches available AA better than app. il. dig. AA. The standardised (st.) il. AA digestibility coefficients (DCAA) were determined for two feeds, close to the animal performance optima, in a digestion trial with four T-cannulated piglets of approximately 6 weeks old. The feed independent endogenous nitrogen excretion was measured with a protein-free feed; although this technique underestimates the actual endogenous N-losses, it provides a reasonable estimate of basal endogenous N-losses. The determined st. il. DCAA were lower than the calculated st. il. DCAA, based on the CVB (2000); this might be linked to the higher than expected crude fibre content of the experimental feeds. The Val-requirement necessary to optimise ADG and FCR was similar and amounted 0.70% st. il. dig. Val, which corresponded with a st. il. dig. Lys-level of 1.03%.

Optimum protein and energy levels for the Thai native frog, Rana rugulosa Weigmann

This study determined the effect of dietary protein and energy levels on growth and feed utilization of the Thai native frog (Rana rugulosa Weigmann). The frogs were fed four isocaloric diets (5300 kcal kg−1) with protein levels 30, 35, 40 and 45% in experiment 1 and with four isonitrogenous (37%) diets with gross energy levels of 4500, 4900, 5300 and 5700 kcal kg−1 in experiment 2. The frogs were fed to apparent satiation twice daily for 12 weeks in three replicate concrete ponds (30 frogs per pond) with an average frog weight of 3.5 and 7.8 g for experiments 1 and 2, respectively. Average weights but not survival rates were significantly different at the end of the study. Feed intake, energy intake and protein efficiency ratio of frogs fed the 30–45% protein diets were not significantly different. Feed conversion ratios of frogs fed the 30% protein diet were significantly higher than for those fed 35, 40 and 45% protein diet. The amount of protein consumed by frogs fed the 30% protein diet was significantly lower than frogs fed the 35, 40 and 45% protein diets. Energy retention in frogs fed the 35% protein diet was significantly higher than other treatments. Protein retention in frogs fed diets with 30 and 35% protein was significantly higher than the frogs fed the 40 and 45% protein diet. The optimum protein level was determined as 36.72%. In experiment 2, frogs were fed with four levels of energy in a diet with a constant protein level of 37%. The average final weight and average daily gain of frogs fed with the 4900 kcal kg−1 diet were significantly higher than the other treatments. Frogs fed with the 4500 kcal kg−1 diet had significantly higher feed intake, feed conversion and lower protein efficiency ratio than frogs fed with the 4900–5700 kcal kg−1 diet. The amount of protein consumed by frogs fed the 4900–5700 kcal kg−1 diet was significantly less than frogs fed diet with 4000 kcal kg−1, but energy consumed by frogs fed the 5300–5700 kcal kg−1 diet was significantly greater than those fed the 4500–4900 kcal kg−1 diet. On the other hand, protein and energy retention in frogs fed the 4900 kcal kg−1 diet were not significantly higher than other treatments. Survival rate and body composition were similar in all treatments. The studies indicate optimum dietary protein, energy and protein to energy ratio were 36.7%, 4900 kcal kg−1 and 74.89 mg kcal−1, respectively.

Effects of dietary protein level on growth and utilization of protein and energy by juvenile haddock ( Melanogrammus aeglefinus)

In order to determine the optimum level of protein required in the diet of juvenile haddock, 750 fish with an average weight of 6.9 g were randomly distributed into each 15 tanks (320 l). Haddock were fed one of five isoenergetic diets containing 45%, 50%, 55%, 60% and 65% protein to satiation. All fish fed the experimental diets for 6 weeks had more than a three-fold increase in body weight, although no significant difference in weight gain was found among treatments. Feed/gain ratio decreased from 0.76 for fish fed 45% protein to 0.62 for fish fed 65% protein. Nitrogen (N) intake increased with an increase in dietary protein, which, in turn, resulted in an increase in N gain of fish whole body. Fish fed 45% protein gained 0.37 g N, which was not significantly different from that of fish (0.40 g) fed 50% protein. Nitrogen gain for fish fed the remaining two diets (55% and 60% protein) had the same value (0.43 g); that was significantly ( P<0.05) higher than fish fed the diet containing 45% protein. The broken-line regression of N gain against dietary protein level yielded an estimated protein requirement of 53.8% ( Y=0.43−0.006( R− X LR), R=53.8±2.08) on a dry-matter basis. Gross energy intake of fish varied from 283 to 229 kJ for fish fed 45% and 65% protein, respectively. The highest energy gain of 119 kJ was obtained with fish fed 50% protein, resulting in the highest energy retention efficiency of 44.1%. The hepatosomatic index of fish significantly ( P<0.05) decreased from 10.7% to 7.3% as dietary protein level increased.

Effects of Dietary Lipid and Energy to Protein Ratio on Growth and Feed Utilization of Juvenile Mutton Snapper Lutjanus analis Fed Isonitrogenous Diets at Two Temperatures

AbstractGrowth and feed utilization of juvenile, hatchery‐reared mutton snapper Lutjanus analis (mean weight = 12.2 g) were compared for 40 d in laboratory aquaria on four isonitrogenous diets (45% crude protein) of varying lipid content (6, 9, 12 and 15%) with energy:protein ratios (E: P; kJ/g protein) of 33.9, 36.3, 38.8, and 41.2, respectively. Growth on these diets was compared under temperatures of 25 and 30 C. Final weights (Wtr) and specific growth rates (SGR) were higher (P &lt; 0.05) at lower dietary E: P ratios of 33.9 and 36.3 (Wtr= 20.3–22.0 g; SGR = 1.25–1.35%/d) than at E:P ratios of 38.8 and 41.2 (Wtr= 17.2‐17.7 g; SGR = 0.84–0.85%/d). Growth at 30 C (Wtr= 21.5 g, SGR = 1.35%/d) was higher (P &lt; 0.05) than at 25 C (Wtr= 17.3 g; SGR = 0.82%/d). Feed consumption (FC) was higher (P &lt; 0.05) at a dietary E: P ratio of 33.9 (1.57%/d) than at 36.3 (1.27%/d) or 38.8–41.2 (0.89–0.98%/d). Growth was highly correlated (P &lt; 0.01) to E: P ratio and to feed consumption. Feed conversion ratio (FCR = 2.17–3.98), protein efficiency ratio (PER = 0.58–1.03) and apparent net protein retention (ANPR = 15.8–20.0%) were not significantly (P &gt; 0.05) affected by dietary E: P ratio. Apparent net energy retention (ANER) was higher (P &lt; 0.05) at E: P ratios of 33.9 and 36.3 (9.50–9.98%) than at E: P ratios of 38.8 and 41.2 (7.15–7.10%). Feed utilization parameters were significantly (P &lt; 0.05) better at 30 C (FC = 1.36%/d; FCR = 2.6; PER = 0.88; ANER = 10.2%) than at 25 C (FC = 1.03%/d; FCR = 3.38; PER = 0.69; ANER = 6.72%), with the exception of ANPR (17.0–17.8%). Maximum growth and energy retention in juvenile mutton snapper using a diet containing 45% crude protein was obtained at dietary lipid levels of 6–9% and E: P ratios of 33.9–36.3 kJ/g protein. Studies which determine optimum protein levels and the effects of reducing E: P ratios below 33.9 kJ/g are needed to improve feed conversion and growth.

Evaluation of the antioxidant potential of natural food/plant extracts as compared with synthetic antioxidants and vitamin E in raw and cooked pork patties

Antioxidant potential for previously identified optimum levels of aloe vera (AV), fenugreek (FGK), ginseng (G), mustard (M), rosemary (R), sage (S), soya protein (SPI), tea catechins (TC) and whey protein concentrate (WPC) were evaluated in raw and cooked patties manufactured from frozen pork. The optimum levels determined were: AV (0.25%), FGK (0.01%), G (0.25%), M (0.10%), R (0.10%), S (0.05%), SPI (0.10%), TC (0.25%) and WPC (4%). Test ingredients were evaluated against synthetic antioxidants butylated hydroxyanisole/butylated hydroxytoluene (BHA/BHT) (0.01%) and a supplemented meat containing natural antioxidant, α-tocopherol (1000 mg α-tocopheryl acetate/kg feed). Ranking the decreasing antioxidant effectiveness of added ingredients in raw patties on day 9 showed that: Control>G>SPI>FGK>AV>M>WPC>S>α-tocopherol>R>TC>BHA/BHT. Cooking resulted in a four-fold increase in TBARS values over raw patties with TC being the most effective antioxidant having significantly ( P<0.001) lower TBARS values than the cooked control on days 3, 6 and 9. Ranking of decreasing antioxidant effectiveness of added ingredients showed that: M>SPI>G>FGK>α-tocopherol>AV>control>S>BHA/BHT>R>WPC>TC. BHA/BHT had the most beneficial effect on cooked meat redness with Hunter ‘a’ values being significantly ( P<0.05) higher than the control on days 3, 6 and 9. Ranking of Hunter ‘a’ values for added test ingredients showed that FGK>WPC>control>R>BHA/BHT>α-tocopherol>TC>AV>SPI>M>G>S on day 9. Hunter ‘L’ and ‘b’ values showed no significant trend over the storage period in either raw or cooked patties. The pH values of both raw and cooked pork control patties and products containing added test antioxidants were variable and while a number of trends were observed, no significant differences were recorded between samples.

Diet development and evaluation for juvenile abalone, Haliotis asinina: protein/energy levels

Juveniles of abalone, Haliotis asinina with mean initial weight and shell length of 0.6±0.03 g and 15±0.07 mm were fed practical diets for 90 days. The practical diets contained graded levels of protein from fish meal, shrimp meal, and soybean meal at 22 (diet 1), 27 (diet 2), and 32% (diet 3) with corresponding estimated metabolizable energy values of 3254, 3150, and 3090 kcal ME/kg diet. The amino acid profile and proximate analyses of muscle meat of the test animal and published nutrient requirements of other species of Haliotids were used as a basis for formulating and developing these practical diets. The diets were fed to abalone at 2–5% body weight once daily (1600 h) for biological evaluation in terms of weight gain (WG), increase in shell length (SL), specific growth rate (SGR), protein efficiency ratio (PER), feed conversion ratio (FCR) and for physical evaluation in terms of shell coloration of the animal. Natural food, Gracilariopsis bailinae (17% CP/2200 kcal ME/kg) (NF) fed ad libitum served as the control. Better growth rates, in terms of WG and SL, FCR and PER were noted in abalone fed the three formulated diets compared with those fed seaweed, G. bailinae. Abalone fed diets 3 (WG: 347%; SGR: 0.81; SL: 140%) and 2 (WG: 307%; SGR: 0.70; SL: 139%) showed significantly better growth rate than those fed diet 1 (WG: 252%; SGR: 0.51; SL: 132%). Natural food-fed abalone had the lowest WG (134%), SGR (0.06) and increase in SL (77%). Survival was generally high at 85–95% for all treatments. FCR (1.5–2.3) and PER (2.19–2.47) for animals fed the three diets were significantly better than for those fed natural food (0.10 PER and 6.98 FCR). Regression analysis showed the optimum protein level for juvenile abalone to be 27% with an energy level of 3150 kcal/kg ME. Abalone juveniles fed the formulated diets produced shells with light bluish green color while those fed seaweed retained the original brown color. Diet 2 which contained 27% protein, 5% lipid and 40% carbohydrates with an energy value of 3150 kcal/kg ME may be used as a basal diet for the rearing of juvenile abalone, H. asinina.

Oxygen consumption and ammonia-N excretion related to protein requirements for growth of white shrimp, Penaeus setiferus (L.), juveniles

An experiment was conducted to study the effect of protein level on the growth rate, survival, pre- and postprandial oxygen consumption, and ammonia (N-NH3) excretion in white shrimp. Penaeus setiferus (L.), juveniles. Diets containing 10%, 20%, 30%, 40% and 50% protein were provided at a proportion of 15% of the dry weight of shrimp weighing 0.19 ± 0.01g. The instantaneous growth rate was recorded for 45 days. The optimum protein level, in terms of the best growth rate, was that of the 30% protein diet (1.1 5g45days−1). All shrimp fed with the diets had significantly higher respiration rates after feeding because of the apparent heat increment (AHI). A greater postprandial nitrogen excretion (PPNE) excretion was also observed after feeding. Shrimp maintained on the 30% protein diet had the lowest AHI and PPNE coefficients (percentage of ingested energyl. and took the least time to reach the oxygen consumption and nitrogen excretion peak. The 0:N ratios varied according to protein level, with higher values (32 and 44, fasting and Feeding, respectively) with a 30% protein diet, and lower values (10 and 13. fasting and feeding, respectively) with 10% and 50% protein diets. These results indicate that P. setiferus juveniles use protein when fed with high (50%) and low (10%) protein diets, and lipid-protein substrates with a 30% protein diet. Under these conditions, P. setiferus grow better with a 30% protein diet where shrimp use food more efficiently.