Effect of Dietary Protein Concentration and Feeding Rate on Weight Gain,Feed Efficiency,and Body Composition of Pond-Raised Channel Catfish Ictalurus punctatus1     

Edwin H. Robinson  Meng H. Li 《Journal of the World Aquaculture Society》1999,30(3):311-318

Two experiments were conducted in earthen ponds to evaluate the effect of dietary protein concentration and feeding rate on weight gain, feed efficiency, and body composition of channel catfish. In Experiment 1, two dietary protein concentrations (28% or 32%) and four feeding rates (≤ 90. ≤ 112, ≤ 135 kg/ha per d, or satiation) were used in a factorial arrangement. Channel catfish Ictalurus punctatus fingerlings (average size: 27 g/fish) were stocked into 0.04-ha ponds at a rate of 24,700 fish/ha. Fish were fed once daily at the predetermined maximum feeding rates for 282 d (two growing seasons). In Experiment 2, three dietary protein concentrations (24, 28, or 32%) and two feeding rates (≤ 135 kg/ha per d or satiation) were used. Channel catfish (average size: 373 g/fish) were stocked into 0.04-ha ponds at a rate of 17,300 fish/ha. Fish were fed once daily for 155 d. In both experiments, five ponds were used for each dietary treatment. Results from Experiment 1 showed no differences in total feed fed, feed consumption per fish, weight gain, feed conversion ratio (FCR), or survival between fish fed diets containing 28% and 32% protein diets. As maximum feeding rate increased, total feed fed, feed consumption per fish, and weight gain increased. There were no differences in total feed fed, feed consumption per fish, or weight gain between fish fed at ≤ 135 kg/ha per d and those fed to satiation. Fish fed the 28% protein diet had a lower percentage carcass dressout and higher percentage visceral fat than fish fed the 32% protein diet. Dietary protein concentrations of 28% or 32% had no effect on fillet protein, fat, moisture, and ash. Feeding rate did not affect FCR, survival, percentage carcass dressout, or fillet composition, except fillet fat. As feeding rate increased, percentage visceral fat increased. Fish fed at ≤ 90 kg/ha per d had a lower percentage fillet fat than fish fed at higher feeding rates. In Experiment 2, dietary protein concentration or maximum feeding rate did not affect total feed fed, feed consumption per fish, weight gain, FCR, or survival of channel catfish. Feeding rate had no effect on percentage carcass dressout and visceral fat, or fillet composition. This was due to the similar feed consumption by the fish fed at the two feeding rates. Fish fed the 24% protein diet had lower carcass dressout, higher visceral fat and fillet fat than those fed the 28% or 32% protein diet. Results from the present study indicate that both 28% and 32% protein diets provide satisfactory fish production, dressed yield, and body composition characteristics for pond-raised channel catfish fed a maximum rate of 90 kg/ha per d or ahove.  相似文献   

Effects of increasing photoperiod length on performance and health of broiler chickens   总被引：2，自引：0，他引：2  

H L Classen  C Riddell  F E Robinson 《British poultry science》1991,32(1):21-29

1. Broiler performance and health were compared from 0 to 42 d for lighting programmes consisting of near-continuous light 23L:1D (23L), a lighting programme where photoperiod gradually increased from 6 to 23 h between days 4 and 35 (INC) or an increasing-lighting programme with 1 h of light mid-way through the scotophase (INC + 1). 2. The increasing lighting programmes reduced growth rate and increased gain:food ratio from 0 to 21 d; INC + 1 growth rate was intermediate to the 23 L and INC treatments. From 0 to 42 d there were no differences in growth rate or gain:food ratio among lighting treatments. Males grew faster, ate more food and converted food more efficiently than females. 3. The increasing-lighting programmes (INC and INC + 1) resulted in less skeletal disease than the 23L control. The incidence of sudden death syndrome (SDS) and mortality other than SDS were numerically lower for the increasing lighting treatments. More males died as a result of SDS and were affected by skeletal defects than females. 4. In terms of health, increasing lighting programmes were superior to near-continuous light for broiler chickens.  相似文献   

Effect of Protein Source and Concentration on Somatic Growth of Juvenile Green Sea Urchins Strongylocentrotus droebachiensis     

Edward J.  Kennedy Shawn M. C.  Robinson G. Jay  Parsons John D.  Castell 《Journal of the World Aquaculture Society》2005,36(3):320-336

Abstract— An important aspect in the development of any aquaculture industry is the maximization of juvenile somatic growth (i.e., body growth) to reduce production time and increase the size of the final product. In this study, green sea urchins Strongylocentrotus clroebachiensis were fed a prepared diet from 4 December 1998 to 10 September 1999 (i.e., 280 d) in a laboratory to investigate the effect of protein source (soybean andlor fish), protein concentration (20,30,40, and 50% dry mass) and juvenile size (4‐8 mm and 12‐20 mm initial test diameter) on somatic growth. A natural diet of Laminwia longicrurus (i.e., kelp) was used as a reference. There was no difference in initial size among the treatments for either the smaller cohort 1 or the larger cohort 2 sea urchins (6.3 mm and 13.8 mm initial average test diameter, respectively) (P > 0.05 for all tests). After 280 d, the sea urchins fed kelp had an average size of 20.7 mm and 24.5 mm (cohort 1 and cohort 2, respectively). The final average sizes of the sea urchins fed the prepared diets, which did not relate to dietary protein concentrations andlor protein source, ranged from 13.2 mm to 16.2 mm (cohort 1) and from 20.4 mm to 22.9 mm (cohort 2), and were significantly smaller than the kelpfed sea urchins (P < 0.05 and P < 0.001, cohort 1 and cohort 2, respectively). All treatments experienced 95% survivorship or greater. Sea urchin size appears to affect growth rate when optimal conditions for growth are available (i.e., diet and water temperature). As water temperatures increased during the summer of 1999, the sea urchins in cohort 1 fed kelp had a significantly higher growth rate (0.069 dd) than the cohort 2 kelpfed sea urchins (0.052 dd) (P < 0.05). However, within each cohort, there were no significant difference in growth rate (P > 0.05) among the sea urchins fed prepared diets, suggesting sea urchins do not require high concentrations of dietary protein for superior growth, and that plant protein can substitute fish protein in sea urchin diets. Furthermore, the sea urchins fed the prepared diets had poorer test quality and larger gonad yields (13‐22%) compared to the kelpfed sea urchins (4.2%) and a wild sample of sea urchins of similar size (4.0%). The results suggest that the sea urchins fed the prepared diets allocated more energy to gonad production, whereas those fed a natural diet allocated more energy toward test production. To address this gap, more research is required to identify the nutritional components required for test growth that were present in kelp, but appeared to be deficient in the prepared diets.  相似文献   

British Columbia: Isolation of influenza A virus from a 7-day-old foal with bronchointerstitial pneumonia     

Ann P. Britton  John H. Robinson 《The Canadian veterinary journal. La revue veterinaire canadienne》2002,43(1):55-56

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Temperature,Mg and Al Interaction Effects on Grass Tetany Potential of Ryegrass Forage1     

Z. Rengel  D. L. Robinson 《Journal of Agronomy and Crop Science》1991,166(5):347-352

Two annual ryegrass (Lolium multiflorum Lam.) cultivars differing in Al sensitivity were grown in nutrient solution at pH 4.2 to assess the effects of temperature (10/6 and 22/18 °C day/night), Mg (0.1 and 1 mM) and Al solution concentrations (0, 3.7 and 74 μ M) on several factors influencing grass tetany potential of forage. Added Al depressed Mg and Ca shoot concentrations and increased shoot K/(Ca + Mg) equivalent ratio especially after prolonged treatment at higher temperature and lower Mg solution concentrations. These effects were more pronounced in the relatively Al-sensitive cultivar Wilo which appeared to be less Mg-efficient as well. Grass tetany potential will therefore be higher following a temperature rise if Al-sensitive ryegrass is grown in a medium containing low Mg and high Al levels.  相似文献   

Validation of candidate bovine reference genes for use with real-time PCR     

Robinson TL  Sutherland IA  Sutherland J 《Veterinary immunology and immunopathology》2007,115(1-2):160-165

Accurate quantification with real-time PCR requires the use of stable endogenous controls. Recently, there has been much debate concerning the stability of commonly used reference or housekeeping genes. To address this concern, a number of statistical approaches have been designed to analyse data and assist in determining the most appropriate reference genes for experimental comparisons. In this study, three programs, BestKeeper, Norm Finder, and geNorm were used to assess four candidate reference genes: 18S rRNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), acidic ribosomal protein large (RPLP0) and beta-actin, for use in expression profiling of individuals from divergent cattle genotypes subject to parasitic challenge with the cattle tick Boophilus microplus. Results demonstrated beta-actin and GAPDH were the most suitable reference genes in blood and could be used either individually or combined as an index to normalise data. RPLP0 was identified as the least stable gene, while 18S rRNA was omitted as being too highly expressed. As the recommendations on the most suitable reference genes varied between the programs, it is recommended that more than one should be utilised, to ensure the most robust experimental tools are selected.  相似文献   

Political Trends in the 60’s     

Alan Robinson 《Asia Pacific viewpoint》1969,10(1):93-102

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Diversity among Finnish net blotch isolates and resistance in barley     

J. Robinson  M. Jalli 《Euphytica》1996,92(1-2):81-87

Summary Seedlings of a differential barley (Hordeum vulgare L.) series (21 genotypes) and of six check genotypes were used in the greenhouse to assess variation in virulence among 20 single-spore isolates of the net blotch pathogen. Pyrenophora teres Drechs. f.teres Smedeg., collected from various sites in Finland. The experiment was run twice and symptom expression was recorded on the first three leaves. Analysis of second leaf symptom scores from Run 1 indicated differences in virulence between isolates, all of which were pathogenic, and differential resistance among the barleys. The virulence of P. teres isolates appeared to be conditioned by the host barley from which the isolate derived; the average virulence of isolates collected from a susceptible host was greater than that of isolates collected from a less susceptible host. Results from Run 2 were similar regarding resistance within the barleys, but variation in virulence among the P. teres isolates was not consistent with that from Run 1. CI 9819 caries duplicate genes for resistance to P. teres (Rpt1b and Rpt1c), and CI 7548 possesses Rpt3d. Both genotypes were highly resistant to all isolates. The Rpt1a gene of Tifang (CI4407) conferred resistance to all isolates in Run 2, but only to about half of the isolates in Run 1. The checks, including two of the symptomatically most resistant Nordic barley genotypes, were universally susceptible during these stringent tests. No selective pressure has been placed on Finnish isolates of P. teres through previous deployment of major resistance genes, and it is speculated that any variation in virulence among isolates is likely to be due to a combination of evolutionary forces including, natural selection, random genetic drift and gene flow.  相似文献   

Book reviews     

K. C. Pillai  B. Z. Siegel  S. M. Siegel  A. S. Kallend  Elmer Robinson  Arthur C. Stern 《Water, air, and soil pollution》1987,32(3-4):461-461

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Acute effects of wood-pulp on sockeye salmon (Oncorhynchus Nerka)     

Arthur E. Werner  Jack Robinson 《Water, air, and soil pollution》1978,9(1):69-81

Freshwater suspensions of pulp fiber in concentrations exceeding 1000 ppm at 15°C are acutely lethal to sockeye salmon fingerlings. Limited adaptation of such fish to fiber is possible but injury, at least in the short term, is irreversible. The acute lethality of various toxicants associated with industrial pulps is synergistically enhanced by the presence of fiber, and pulp storage up to 158 days at 15°C had no significant effect on the acute lethality. Highly purified fibers are less toxic in fresh than in sea water. The sensitivity to fiber of fish from two sources did not differ significantly.  相似文献