Laura A. Muzinic

Partial and total replacement of fish meal with soybean meal and brewer's grains with yeast in practical diets for Australian red claw crayfish Cherax quadricarinatus

Three feeding studies were conducted to evaluate the effects of total replacement of fish meal (FM) with a combination of soybean meal (SBM) and brewer’s grains with yeast (BGY) in diets for two separate strains of juvenile Australian red claw crayfish. In Experiment 1, three practical diets were formulated to be isonitrogenous (40% protein) and isocaloric (4.0 kcal available energy/g diet) and contained either 25%, 10%, or 0% fish meal. Variable percentages of SBM (35%, 46.8%, and 79.8%, respectively) and BGY-35 (0%, 30%, and 5%, respectively) replaced the fish meal. In Experiments 2 and 3, four practical diets were formulated to be isonitrogenous (40% protein) and isocaloric (4 kcal available energy/g diet) containing 24% or 0% fish meal. Diet 1 contained 24% fish meal, 23% SBM, and 0% BGY-35. A variable percentage of SBM (56.75%, 47.75%, and 40.75%, respectively) and BGY-35 (10%, 20%, and 30%, respectively) replaced the fish meal in the remaining three diets. In Experiment 1, after 8 weeks, juvenile red claw fed all three diets had no significant difference (P>0.05) in final weight, percentage weight gain, or survival, which averaged 7.90 g, 3848%, and 83%, respectively. In Experiment 2, after 8 weeks, juveniles fed all four diets had no significant difference in final weight, percentage weight gain, or specific growth rate which averaged 11.46 g, 977%, and 3.08%/day, respectively. Percentage survival was not significantly different among treatments and averaged 79%. In Experiment 3, after 8 weeks, juvenile red claw fed all four diets had

Quality Changes in Australian Red Claw Crayfish, Cherax quadricarinatus, Stored at 0°C

Abstract Shell-on tails of 70 juvenile Australian red claw crayfish, Cherax quadricarinatus, were separately packaged in seven sealed plastic freezer bags (10 in each) and stored on ice (0°C) for 0, 1, 3, 5, 7, 10, and 14 days. At the end of each storage period, raw muscle homogenate from five tails (pooled) were analyzed for lipid peroxidation, proteolysis (electrophoreis), and thermal stability (differential scanning calorime-try). The other five tails were individually cooked (2 minutes boiling) to determine cooking yield and toughness (Warner-Bratzler shear). Lipid oxidation occurred during storage (e.g., TBA values increased from 0.341 mg/kg on day 0 to 1.492 mg/kg on day 14, P< 0.05). Myofibrillar and sarcoplasmic proteins were generally resistant to proteolysis, but were destabilized during storage. Transition temperatures for myosin head and actin decreased (P# 0.05) from 50.2°C and 72.6°C on day 0, to 39.4°C and 60.3°C by day 14, respectively; while enthalpy of denatur-ation for myosin head reduced from 0.324 J/g to 0.116 J/g during this pe-riod. Storage also resulted in a gradual loss in cooking yield, which correlated (R = 20.82, P >0.05) with progressive toughening of cooked meat. The results indicate that red claw muscle is susceptible to protein denaturation and lipid oxidation, and these chemical changes may be responsible for decreased cooking yield and reduced tenderness of meat during extended refrigeration storage.

A Preliminary Assessment of Growth, Survival, Yield, and Economic Return of Australian Red Claw Crayfish, Cherax quadricarinatus, Stocked at Three Densities in Earthen Ponds in a Cool, Temperate Climate

Abstract Juvenile (mean weight 8.1 g) Australian red claw crayfish, Cherax quadricarinatus, were stocked in July at three rates of 12,000/ha, 18,000/ha, and 24,000/ha into two, 0.02-ha earthen ponds in a cool temperature region of the United States (Kentucky) and grown for 70 days. Red claw were fed a pelleted marine shrimp diet twice daily. Ponds had continual aeration provided. Dissolved oxygen and temperature were measured twice daily (0900 and 1530 hours); total ammonia nitrogen (TAN), nitrite, and alkalinity were measured twice weekly; and pH was measured daily. At harvest, there were no significant (P > 0.05) differences in final individual weight, percentage weight gain, specific growth rate, feed conversion ratio, percentage survival, yield, and economic return among all treatments and averaged 58.4 g, 805%, 3.04%/ day, 7.47,42.7%, 461 kg/ha, and -

Growth, Processing Measurements, Tail Meat Yield, and Tail Meat Proximate Composition of Male and Female Australian Red Claw Crayfish, Cherax quadricarinatus, Stocked into Earthen Ponds

2659/ha, respectively. There were no significant (P > 0.05) differences in the percentage of males and females harvested from the ponds among any stocking rate with males comprising 48.2% and females comprising 51.8%. Final individual weight of males and females was not significantly (P > 0.05) different among all treatments. These data indicate that there is no advantage to stocking red claw at rates below 24,000/ha in terms of growth, survival, yield, and economic return and that red claw can grow to marketable size in a cooler temperate region of the United States with a short (<110 days) growing season by stocking a larger-size (8 g) red claw.

Use of Turkey Meal as a Replacement for Menhaden Fish Meal in Practical Diets for Sunshine Bass Grown in Cages

Abstract Small (0.7 g) juvenile red claw, Cherax quadricarinatus, were stocked in earthen ponds (0.04 ha) in Kentucky and grown for 86 days so that measures of growth, survival, processing characteristics, and proximate composition of tail muscle in male and female Australian red claw crayfish could be obtained. A commercial marine shrimp was fed to all red in two separate feedings, each consisting of one-half of the total daily ration between 0800-0830 and between 1530-1600 hours for the duration of the culture period. Total weight and number of red claw from each pond were recorded at the harvest. Forty red claw from each sex were randomly sampled, chill-killed by lowering the body temperature in an ice-bath, and frozen (-20°C) for processing measurements and proximate composition. Red claw were removed from the freezer, thawed, individually weighed to the nearest 0.01 g, and then were hand-processed so that weights of chelae, tail, and tail muscle were obtained to the nearest 0.01 g. After 87 days, red claw had a final average individual weight of 59.6 g, weight gain of 8,413%, survival of 64.0%, yield of 903 kg/ha, and feed conversion ratio (FCR) of 4.63. When analyzed by sex, males had significantly (P < 0.05) higher final individual weight (71.05 g) compared to females (53.65 g); higher (P < 0.05) chelae weight (13.1 g for males compared to 6.84 g for females); higher tail weight (25.53 g for males compared to 20.38 g for females); higher tail muscle weight (18.99 g for males compared to 14.89 g for females); and higher cephalothorax weight (32.41 g for males compared to 26.44 g for females; Table 2). There were no significant differences (P > 0.05) in the percentage moisture, protein, lipid, fiber, and ash in the tail muscle of male and female red claw when analyzed either on a wet-weight basis and averaged 81.0%, percentage protein averaged 16.46%, percentage lipid averaged 0.16%, fiber averaged 0.1%, and percentage ash averaged 1.42%. Results from the present study indicate that red claw can be grown as a commercial aquaculture species in locations with limited growing seasons, and that male red claw grow larger, have larger chelae, and higher tail muscle weights compared to females so that it might be economically advantageous to stock all-male populations of red claw in ponds to achieve maximum production. Further research on growth and processing yields of red claw should be conducted to assist the industry.

Evaluation of practical diets containing different protein levels, with or without fish meal, for juvenile Australian red claw crayfish (Cherax quadricarinatus)

Abstract A 391-d feeding trial was conducted with caged juvenile (mean weight = 36.2 g, SD = 8.04 g) sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) to evaluate growth, feed conversion, protein efficiency ratio, body composition, and fillet composition resulting from diets with decreasing levels of fish meal (FM; 30, 20, 10, and 0%) and increasing levels of turkey meal (TM; 0.0, 9.7, 17.5, and 26.4%). We stocked 100 randomly selected fish into each of 12 floating cages (3.5 m3). Twice daily, fish were fed all they could consume in 30 min. Four practical diets were formulated to contain 40% protein and to be isoenergetic. After 391 d, significant (P ≤ 0.05) differences were found in growth; fish fed the control diet (30% FM, 0% TM) had higher individual final weight, percent weight gain, and specific growth rate than fish fed 10.0% FM and 17.5% TM. However, differences for those variables were not apparent between the control group and fish fed the 20% FM and 9.7% TM diet...