Apparent Net Protein Utilization Research Articles

The requirement of the gilthead seabream (Sparus aurata L.) for nicotinic acid

AbstractSemi-purified diets were used to determine the nicotinic acid requirement of the gilthead seabream, Sparus aurata. Vitamin losses during food manufacture were minimal resulting in dietary levels which were close to the declared content. Dietary nicotinic acid contents of 52·21 mg/kg and below resulted in sub-optimum growth, reduced food efficiency and poor values for apparent net protein utilization. Diets containing less than 28·67 mg/kg gave a low proportion of carcass lipid concomitant with an elevation in the relative content of carcass moisture. Although gross deficiency symptoms were not observed, a reduced hepatosomatic index and a slightly lower plasma glucose concentration were detected amongst the fish given diets supplemented with nicotinic acid at the level of 25 mg/kg or less. Based upon the results of broken line analysis and data derived by modelling the weight gain of the fish, the nicotinic acid requirement of Sparus aurata fingerlings lies between 63 and 83 mg/kg of diet or 1·57 to 2·07 µg/kg body weight per day.

The effect of pyridoxine supplementation on dietary protein utilization in gilthead seabream fry

A study was undertaken to ascertain the effect of pyridoxine in diets of varying protein to energy ratio (P: E) for Mediterranean gilthead seabream fry (Sparus aurata) with respect to protein utilization. Diets were formulated to provide three levels of added pyridoxine (0·5, 5·0 and 50·0 mg/kg), at two protein levels (320 or 470 g/kg) whilst maintaining a similar gross isocalorific profile at 20 MJ/kg. Feeding level was proportionately 0·02 of the fish body weight per day, resulting in the following effects after a 70-day feeding trial. Low P: E ratio diets (15 g/MJ) did not perform as well as high P: E diets (24 g/MJ), with respect to growth related indices. Higher inclusions of pyridoxine into diets of equal P: E ratios, caused elevations in food conversion efficiency, protein efficiency ratio and apparent net protein utilization. A marked improvement of growth rate concomitant with pyridoxine level only occurred in the high P: E diets. It was concluded that incremental additions of pyridoxine in the diet, increased the efficiency of protein utilization for all diets tested. However, the protein sparing effect oflipid was not achieved for the low protein diets indicating the relatively high requirement for protein in the growth of the juvenile seabream.

Optimum dietary protein requirement of a Malaysian freshwater catfish, Mystus nemurus

Six isoenergetic pratical diets ranging from 27% to 50% protein were fed for 12 weeks to triplicate groups of the freshwater catfish Mystus nemurus (25.4±0.89 g body weight and 12.80±0.4 cm total length). The fish were cultured in a recycling water system maintained at ambient environmental temperature. Weight gain was directly proportional to protein levels up to an incorporation rate of 42%; beyond this level no significant growth ( P>0.05) either in weight gain or protein gain was observed. Protein efficiency ratio (PER) decreased with increasing protein level. Apparent net protein utilization (ANPU) parabolically increased with increasing dietary protein level but decreased when dietary protein level exceeded 42%. Carcass fat and protein content were negatively correlated while ash content was not affected by varying dietary protein levels. Weight gain, food conversion ratio (FCR), PER and ANPU indicated that a 42% protein diet with digestible protein to energy ratio ( DP E ) of 113.82 mg/kcal produced maximum growth under the experimental conditions used.

Untersuchungen zum eiweissumsatz verschiedener leghornhybriden

After N-balance experiments with leghorn-hens of five different genetic origins in the top laying period, the advanced laying period as well as at the end of the laying period and with feeding of soybean meal/fish meal protein, the nitrogen maintenance requirement per live weight kg0.67 was ascertained regressively by approximation of the N-balance from N-increasing experiments to an exponential function. The Net Protein Utilization (PNu) curve and the apparent Net Protein Utilization (PEW) curve could be described as utilisation values from the N-retention curve (e-function). Moreover the relation between N-intake/LW kg0.67 and egg-N-discharge/LW kg0.67 from N-balance made it possible to estimate N-retention in the body. Finally, capability of the five origins at equal protein and S-AA intake respectively were compared.

Initial feeding of European minnow larvae, Phoxinus phoxinus L. 1. Influence of diet and feeding level

European minnows ( Phoxinus phoxinus L.) were reared on natural (frozen Artemia nauplii), dry and mixed diet (50% Artemia and 50% dry food) from hatching to weaning size in order to determine an adequate food supply during their larval growth. The suitability of the different diets was assessed on the basis of survival, growth rate, food conversion ratio, protein efficiency ratio and apparent net protein utilization during the first 4 weeks of larval rearing. Best survival rate, growth and food utilization were attained with the frozen Artemia nauplii or mixed diet. From an initial body weight of 1.86 mg at hatching, P. phoxinus larvae reached about 30 mg in 4 weeks and the survival rate was higher than 96%. On the other hand, the dry diet was not suitable for minnow larvae and fish ceased to grow after 3 weeks and mortality increased. The mixed diet was used to evaluate the quantitative food requirements by determining the maintenance, optimum and maximum daily rations according to the weight of larvae (1.86, 4.3 and 15.7 mg).

Sensory and Nutritional Properties of Cookies Based on Wheat‐Rice‐Soybean Flours Baked in a Microwave Oven

ABSTRACTThree formulas of cookies prepared from 50:45:5 (I), 50:40:10 (II) and 50:35:15% (III) wheat flour, broken rice flour, and defatted soy flour, respectively, baked in a microwave oven (2450 MHz) for 240 sec, were rated as the best of six formulas for flavor and texture by a trained panel. Cookies of formulas I and II were preferred over formula III by a consumer‐type panel. Cookies of all three formulas showed no significant differences in nitrogen balance, apparent biological protein value and apparent net protein utilization. Apparent protein digestibility and protein efficiency ratio were significantly higher in formulas II and III than in formula I.

Feed intake and growth of red tilapia at different stocking densities in ponds in Indonesia

Red tilapia (phenotypicallyOrenchromis niloticus) fingerlings, obtained from the Provincial Fisheries Service in East Java, Indonesia, were stocked at 0.125, 1, 4, 12, and 20 fish /ml in 32 m2 stagnant water concrete ponds and fed ad libitum on commercially available pelletized diets containing (on dry matter basis) 28.2 and 28.8% crude protein and 19.0 and 19.1 kJ g−1 energy respectively. Maximum yield of 17.0 kg/pond per 8 weeks (or 5.3 tonnes/ha per 8 weeks) was obtained at a stocking density of 12 fish/m2. while the average individual growth rate was highest for the lowest density. The relative growth rate of the metabolic weight (RGRm) increased linearly with the feed intake expressed as metabolic ration (Rm) and is given by the equation: RGRm = 0.790*Rm − 2.571 (r2 = 0.63). Maximum RGRm values were realized in the first 4 weeks for the lowest densities and ranged between 30.1 and 34.0 g kg−0.8 d−1 (measured over 2-week periods). Maintenance ration was calculated to be 3.25 g kg−0.8 d−1 (or 62.0 kJ kg−0.80 d−1). These values are compared with recalculations of results in the literature. The apparent net protein utilization (NPUa) averaged 42.5% for the 0.125, 1, 4, and 12 fish/m2 treatments. Taking the marketable size of 100 g into consideration, a stocking density of 4 fish/m2 is recommended.

Interactions of varying dietary protein and lipid levels in young red tilapia: Evidence of protein sparing

A 12-week feeding trial was carried out with young red tilapia, a hybrid of Oreochromis mossambicus and O. niloticus, with a mean weight of 1.185 g. Three series of isocaloric, experimental diets of 15%, 20% and 30% protein content (by dry weight) and for each series, four diets of 6%, 12%, 18% and 24% lipid content were tested. At all three protein levels the best growth was obtained with diets of 18% lipid. Daily consumption (in mg/g fish day −1) was correlated negatively to the digestible energy content of the diets, and overall rate of growth positively to the mean daily protein consumption (per g fish per day). The food conversion ratio ranged from 1.10 (P 30L 24) to 2.32 (P 15L 12), the protein efficiency ratio from 2.18 (P 30L 6) to 3.56 (P 20L 18) and apparent net protein utilization from 19.9% (P 15L 6) to 42.95% (P 30L 18), where P and L refer to dietary protein and lipid, and the subscripts to the approximate percentage. The carcass lipid and protein reflected the dietary regimes. The study indicates the protein-sparing capabilities of young red tilapia. The protein-sparing capability increased with increasing dietary lipid content up to 18% and decreased thereafter.

Nutritional evaluation of some Bangladeshi oilseed meals as partial substitutes for fish meal in the diet of common carp, Cyprinus carpio L.

. Three oilseed meals (mustard, linseed and sesame) of Bangladeshi origin were evaluated as fish meal substitutes in diets of common carp, Cyprinus carpio L. These oilseed meals were included in the diet at various levels (25, 50 and 75% of dietary protein) and the response of fish fed these diets was compared to fish fed a fish meal based control diet (40% protein). On the basis of observed growth rate, food conversion ratio, protein efficiency ratio and apparent net protein utilization, the control diet produced significantly (P< 0.05) the best growth performance. Growth responses were significantly affected by both type and inclusion level of oilseed protein. Of the oilseed proteins tested, the 25% mustard protein and 25% linseed protein diets produced significantly (P< 0.05) better growth performances than higher inclusion levels tested. Apparent protein digestibilities (APDs) for all diets were fairly high, ranging from 77.72 to 89.8O%. In general, APD values decreased with increasing plant protein. Fish fed diets containing higher levels of oilseed protein had significantly (P< 0.05) higher carcass moisture and lower carcass lipid contents. Fish fed 50% mustard protein had histological abnormalities in liver and thyroid tissues. Results are discussed with respect to dietary levels of essential amino acid and anti-nutritional factors.

DIGESTIBILITY AND ACCEPTABILITY OF OAC WINTRI TRITICALE BY GROWING PIGS

The digestibility and acceptability of OAC Wintri triticale were evaluated in two trials. In trial 1, three diets in which triticale replaced 0, 50 or 100% of corn were fed to 12 barrows individually housed in digestion crates. No significant difference was observed in dry matter digestibility among diets. Daily fecal nitrogen, daily absorbed nitrogen and apparent protein digestibility adjusted to equal nitrogen intake responded quadratically (P &lt; 0.01) to increasing levels of triticale in the diets. There were no significant differences in daily retained nitrogen, apparent biological value or net protein utilization among diets. Gross energy digestibility, digestible energy (MJ kg−1) or metabolizable energy (MJ kg−1) were not different among diets. The second trial involved pair-feeding 48 pigs (average initial weight 36.7 kg) for 28 d to ascertain the acceptability of triticale to pigs utilizing the same diets as in trial 1. Increasing levels of dietary triticale resulted in a linear reduction (P &lt; 0.001) in feed consumption and growth rate with pigs fed ad libitum. Feed efficiency was poorest when pigs consumed the highest level of triticale. The pair-feeding experiment indicated that pigs fed the diet in which triticale replaced 100% of the corn had a lower growth rate than pigs fed the corn diet even though feed intake on the two diets was similar. In summary therefore, all diets had a similar digestibility. OAC Wintri triticale was less acceptable to pigs, presumably due to poorer palatability, and resulted in lower daily gain than corn. The pair-feeding trial indicated that unknown antinutritional factors may be responsible for part of the poor performance of pigs fed this variety of triticale. Key words: OAC Wintri triticale, digestibility, acceptability, performance, growing pigs

Nutritive Value of Whole Soybeans Fermented with Aspergillus oryzae or Rhizopus oligosporus as Evaluated by Neonatal Pigs

Two experiments were conducted to evaluate the nutritive effects of heated whole soybeans fermented with the mold Aspergillus oryzae (AOS) or Rhizopus oligosporus (ROS) in diets fed to neonatal pigs from 1 to 22 d of age. In experiment 1, either soybean meal or heated whole soybeans fermented with ROS replaced 75% of the dried skim milk protein. The average daily gain (ADG) and gain-feed (G-F) ratio of pigs fed the diet containing 100% milk protein were greater than those of pigs fed the diets containing either soybean meal or ROS. In experiment 2, heated nonfermented whole soybeans (HUS) or heated whole soybeans fermented with either AOS or ROS replaced 50% of the milk protein in isonitrogenous and isoenergetic diets. Proximate and amino acid analyses of HUS and the fermented soybean products, AOS and ROS were similar. Pigs fed a diet containing either HUS or AOS had greater (P less than 0.05) mean ADG and G-F ratios than pigs fed the diet containing ROS. Apparent biological value, apparent net protein utilization and digestible and metabolizable energy utilization were similar for all dietary treatments. In conclusion, the protein and energy values of whole soybeans were not improved by fermentation with ROS or AOS compared to nonfermented heated whole soybeans, soybean meal or dried skim milk in diets fed to neonatal pigs.

Quantitative feed requirements of African catfish ( Clarias gariepinus Burchell) larvae fed with decapsulated cysts of Artemia: I. The effect of temperature and feeding level

In a series of four experiments, the effects of temperature (range: 25.0–32.5°C) and feeding level on the growth performance and survival rate of first-feeding larvae of the African catfish ( Clarias gariepinus Burchell) was assessed. Feeding occurred with dried decapsulated cysts of Artemia. Growth performance was determined on the basis of growth rate, food conversion ratio, energy conversion efficiency, protein efficiency ratio, and apparent net protein utilization. A new approach to assess growth rate and feeding levels in larval nutrition studies is presented and discussed. The quantity of decapsulated Artemia cysts and the time needed to raise larvae of Clarias gariepinus up to a weight of 50 mg for different combinations of temperatures and feeding level were determined. Recommendations are made for optimal temperature and feeding level under practical farming conditions.

Dietary protein requirement of fingerlings of the herbivorous carp tawes, Pontius gonionotus (Bleaker)

. The dietary protein requirement of fingerlings of Pontius gonionotus (Bleaker) was investigated by feeding five isoenergetic semi-purified diets containing varying levels of dietary protein within a range of 15%–557% by weight over a 70-day feeding period. On the basis of percentage weight gain, daily weight gain, specific growth rate and daily tissue protein deposition the dietary protein requirement of fingerlings of P. gonionotus was approximately 35% when fish meal, blood meal and casein were used as the dietary protein source. Feed conversion ratio, protein efficiency ratio and apparent net protein utilization all decreased with increasing dietary protein levels while apparent protein digestibility was not significantly affected. There was a significant increase in carcass moisture and a decrease in carcass lipid content with progressive dietary protein substitution whilst carcass protein and ash were relatively unaffected.

OAC WINTRI TRITICALE IN DIETS OF GROWING SWINE

Two performance trials and two metabolism trials were conducted to evaluate the feeding value of two samples of OAC Wintri triticale for growing swine. The samples of triticale contained 15.5% (triticale A) or 10% (triticale B) protein on a dry matter basis. In trial 1, each sample replaced 0, 25, 50, 75 or 100% of protein from corn in a 15% protein (as-fed) corn-soybean meal diet. Diets had a constant soybean meal level and cornstarch was added as appropriate to make diets isonitrogenous. Each diet was fed to five individually penned pigs (average weight 22 kg). Forty-eight pigs were utilized in a 2 × 2 × 3 factorial arrangement of triticale sample (triticale A or triticale B), dietary protein (15 or 17%) and percent corn replaced (0, 50 or 100%) in trial 2. Soybean meal in diets was adjusted as appropriate to obtain a 15 or 17% protein diet. Daily gain (P &lt; 0.10) and feed consumption (P &lt; 0.05) were greater for pigs fed triticale B than triticale A in both experiments. While feed efficiency was not different between the two samples of triticale in trial 1, triticale B had better (P &lt; 0.01) feed efficiency than triticale A in trial 2. The corn-soybean meal diet promoted faster gains and higher feed consumption (P &lt; 0.05) than the triticale A-soybean meal diet. As the level of triticale A in the diets increased, daily gain, feed intake and feed efficiency declined in both trials. Digestible and metabolizable energy values (kcal g−1) declined (P &lt; 0.01) linearly as level of triticale in the diet increased. Dry matter digestibility declined (P &lt; 0.01) as the level of triticale increased in trial 2 and as the level of triticale B in diets increased in trial 1. There was no change in dry matter digestibility as the level of triticale A in diets increased in trial 1. Biological value and net protein utilization were lower (P &lt; 0.01) for diets containing triticale A than triticale B. Level of triticale in diets did not affect apparent protein digestibility, biological value and net protein utilization (P &gt; 0.10) in either trial. In a soybean-meal-supplemented diet, the energy value of triticale relative to corn appears to be about 90%. Key words: OAC Wintri triticale, digestibility, energy, pigs, performance, protein

Use of cassava as an energy source in a pelleted feed for the tilapia, Oreochromis niloticus L.

Abstract. An assessment of the nutritive value of cassava as an energy source in a pelleted lilapia diet was carried out. Four isonitrogeneous diets containing 15%. 30%, 45% and 60% cassava were formulated and fed to groups of Ortochromis niloucus L for 10 weeks. Good growth and food utilization efficiencies were obtained with all diets: there was a trend of improved growth and food utilization with increased cassava incorporation in the diet although there were no significant differences (P < 0–05) in food conversion ratio, protein efficiency ratio or apparent net protein utilization between the experimental diets. No nutritionally related pathology was observed in fish fed high cassava levels. Increased incorporation of cassava led to an increase in the carcass fat content although it was within the acceptable limits for tilapia. Phytoplankton growth occurred in all experimental tanks due to the fertilization effects of uneaten feeds and faeces as the water within the experimental lankiyuem was not exchanged: the contribution of phytoplankton to the nutrition of the experimental fish was not quantified but was considered to be minimal since the phytoplankton biomass was approximately an order of magnitude less than in fertilized systems.

Composition and Protein Quality of Honeybee-Collected Pollen of Eucalyptus marginata and Eucalyptus calophylla

The composition and protein quality of the two most important Western Australian export-quality pollens were investigated. Crude pollen protein content was 20.6% and 27.9% for Jarrah (Eucalyptus marginata) and Marri (Eucalyptus calophylla), respectively. Lysine was the limiting amino acid relative to the FAO protein scoring pattern (Food and Agriculture Organization of the United Nations), and the amino acid scores were 0.73 and 0.66 for Jarrah and Marri pollen, respectively. Apparent biological value (BV) was 61.7 for Jarrah pollen, 66.9 for Marri pollen and 71.4 for the casein controls. Adjusted protein efficiency ratio (PER) values were 2.5, 1.2 and 1.1 for casein and Jarrah and Marri pollens, respectively. Apparent net protein utilization (NPU) was significantly reduced for both pollens (32.8 for Jarrah and 39.5 for Marri) compared to casein (63.6). The low apparent NPU values result from the relatively low digestibility of pollens. Apparent digestibility was 52 and 59% for Jarrah and Marri pollen compared to 89% for casein. Although both Jarrah and Marri pollen are relatively high in protein and have favorable amino acid patterns, their relatively low digestibility will be a limiting factor in their usefulness as a food food for humans and monogastric animals. The proximate analysis and mineral content of the pollens are also presented.

A preliminary study on the dietary protein requirement of juvenile snakehead.

The dietary protein requirement of juvenile snakehead Channa micropeltes was in vestigated by feediung eight semipurified diets containing varying levels of dietary protein within a range of 25.5 to 56.5% by weight over a 56-day feeding period at 28°C. On the basis of daily weight gain and daily protein deposition these results indicate that the requirement by juvenile snakehead for dietary protein was about 52% of protein in the diet when fish meal is used as the sole protein source. The relationship between dietary protein level and food conversion ratio, protein efficiency ratio, apparent net protein utilisation, apparent protein digesti-bility, apparent dry matter digestibility, hepatosomatic index, and gross carcass composition were determined and discussed in relation to other fish species.

Utilization of glucosev. lactose in an isolated soya bean protein diet by neonatal piglets reared artificially

ABSTRACTForty-eight 1-day-old pigs were used to compare lactose and glucose as the carbohydrate source for piglets from 1 to 22 days of age. Average daily gains, gain over feed ratios and the apparent digestion coefficients for crude protein, ether extract, nitrogen-free extract, ash, energy and dry matter were similar for the two groups. Apparent net protein utilization was greater with the glucose diet than with the lactose diet (P&lt;0·05), although their apparent biological values and metabolizable energy values were similar. The serum levels of total glucose, total protein and urea nitrogen were also similar for both groups. Serum levels of total protein and urea nitrogen declined with age while the trend for total glucose was inconsistent. Subsequent nursery performance from 22 to 64 days of age when all pigs were fed the same diet was not influenced by the previous neonatal dietary treatment.

Evaluation of a Yeast Single Cell Protein with Young Pigs

The digestibility and utilization of nitrogen (N) were compared between a yeast single-cell protein (SCP) and dehulled soybean meal (SBM) during two, 5-day total collection periods. Semipurified diets supplying 18% crude protein from either SCP or SBM as the only protein sources were fed in a metabolism trial to 12 pigs that weighed 5.6 kg at the beginning of the experiment. Both diets were supplemented with methionine. These same pigs were used in an intermediate period to obtain estimates of metabolic fecal nitrogen (MFN) and endogenous urinary nitrogen (EUN) of .101 and .313 g/lOOg of feed intake, respectively. These estimates were made by extrapolating nitrogen intake to zero from low protein (3, 6, 9 and 12%), dried skim milk diets. Apparent dry matter and N digestibility coefficients were higher (P<.01) for the SCP than for the SBM diet. The differences between diets were greater in period 1 than in period 2 (interactions, P<.01 for DM and P<.05 for N). Apparent biological values (BV) of 72.5 and 73.7 for SBM and SCP, respectively, were not significantly different (P>.10). Apparent net protein utilization (NPU) values of 64.8 and 69.3 for SBM and SCP diets, respectively, differed (P<.10) and the source difference was greater in period 1 than in period 2 (interaction, P<.10). True BVs of 84.4% and 84.1% were similar, as were true NPU values of 78.1 and 81.6% for SBM and SCP diets, respectively. Plasma urea N levels, but not plasma α-amino N, were higher (P<.05) 4 hr after feeding in pigs fed SBM than in those fed SCP. In a second experiment the yeast SCP product replaced none, one-third, two-thirds or all of the SBM in the diet of weanling pigs. Diets were not supplemented with methionine. The SCP levels did not affect (P>.05) average daily gain (ADG), average daily feed intake (ADF) and gain to feed ratio (G:F). As SCP level increased, the plasma urea N (PUN) level decreased (linear and quadratic effects, P<.01). Diets did not affect plasma α-amino N concentration. In a third experiment, the SCP product, at a level that replaced 50% of the SBM in the diet, was compared with a second SCP product at the same feeding level and with a control diet containing no SCP. Diets were not supplemented with methionine. Source of protein did not (P>.05) differentially affect ADG, ADF, G:F, PUN and plasma a-amino N of weanling pigs. Results of these experiments indicate that the SCP product described and tested is an excellent protein feedstuff for use in diets fed to weanling pigs.

The use of fish meal and soyabean meal as a protein source in the diet of grass carp fry

Diets based on fish meal and soyabean meal were fed to grass carp fry, the average body weight of each individual being 0.4 g. During the 70 days of the experiment, the best results were obtained with a diet containing 40% fish meal, when growth increment, protein efficiency ratio and apparent net protein utilization amounted to 209, 1.26 and 20.3, respectively. There was a deficiency in sulphuric amino acids in both fish meal- and soyabean meal-containing diets, and this was particularly marked in the latter. A significant decrease in available lysine was found in the diets containing soyabean meal. The main reason for the retardation in fish growth and the reduction of protein utilization when soyabean meal content is increased in the diets, seemed to be that the destruction of anti-nutritional factors by the heat processing of the meal was only partial.